DE102019121882A1 - Solar module and method for optimizing a solar module - Google Patents

Abstract

The present invention relates to a method for optimizing an interconnection of a solar module (27) which has a plurality of solar elements (20). The method includes providing a plurality of predetermined types of interconnection according to which the solar elements (20) within the solar cell module (27) can each be interconnected, sequential interconnection of the solar elements (20) according to the predetermined interconnection types and determining an efficiency parameter of the solar module (27) for each interconnection according to one of the predetermined interconnection types and a determination of an optimal interconnection type of the predetermined interconnection types in which the solar module (27) has the best efficiency parameter. The method also includes interconnecting the solar module (27) in accordance with the optimal type of interconnection. The invention also relates to a method for optimizing a solar cell arrangement (1), as well as a solar module (27) and a solar cell arrangement (1).

Description

The present invention relates to a solar module and a method for optimizing a solar module, as well as a solar cell arrangement and a method for optimizing a solar cell arrangement. The invention is therefore particularly in the field of photovoltaics.

Series connections of solar modules in solar cell arrangements conventionally lead to a loss of efficiency if the solar modules are partially or completely shaded, since a shaded solar element can at least partially block the current flow of the other solar elements and even be damaged.

Since the shading situations or shading conditions can change during operation of the solar cell arrangement, a conventional, rigid connection of the solar elements, as in the prior art, is disadvantageous.

The dynamic interconnection presented is a further development of lessons from the publications DE102011055754A1 and WO2012163908A2 .

Bypass diodes, which are supposed to protect individual solar elements, such as solar cells or solar cell strings, work in a similar way to a voltage-controlled switch. In integrated form this is z. B. known as the Cool Bypass Switch.

Dynamic interconnection can solve further problems that are named in the prior art. This includes protection for firefighters, as in the JP2014068509 (A ) as well as a power limitation as in the US 2015155818 A1 . The problem of the so-called thermal runaway (thermal runaway with self-destruction) of bypass diodes is addressed in the EP1970965A1 pointed out.

Starting from the prior art, the invention is based on the object of designing an electrical circuit concept which avoids the disadvantages of the prior art listed above. In particular, it is the object of the invention to provide solar modules and methods for optimization which have an optimized efficiency even in changing shading situations and which minimize performance losses due to partial shading.

The invention relates to a solar module, a method for optimizing a solar module, a solar cell arrangement and a method for optimizing a solar cell arrangement with the features of the respective independent claims. Preferred embodiments are specified in the dependent claims and in the description.

In a first aspect, the invention relates to a method for optimizing an interconnection of a solar module which has a plurality of solar elements. The method includes providing a plurality of predetermined types of interconnection according to which the solar elements within the solar cell module can each be interconnected, as well as sequential interconnection of the solar elements according to the predetermined interconnection types and determination of an efficiency parameter of the solar module for each interconnection according to one of the predetermined interconnection types and determining an optimal type of interconnection of the predetermined types of interconnection in which the solar module has the best efficiency parameter. Furthermore, the method has an interconnection of the solar module according to the optimal interconnection type.

In a further aspect, the invention relates to a method for optimizing a solar cell arrangement with a plurality of solar modules and an inverter, the solar cell modules being connected in series and connected to an input of the inverter. The method comprises setting the solar cell arrangement to an operating point with an optimized operating current by means of the inverter and optimizing the interconnection of the solar modules according to the invention.

In a further aspect, the invention relates to a solar module, the solar module being set up to provide a plurality of predetermined types of interconnection according to which the solar elements within the solar module can each be interconnected, as well as a sequential interconnection of the solar elements according to the predetermined types of interconnection and the determination of an efficiency parameter of the solar module for each interconnection according to one of the predetermined interconnection types. Furthermore, the solar module is set up to have an optimal type of interconnection of the predetermined types of interconnection determine at which the solar module has the best efficiency parameter, and to interconnect the solar module or the solar elements of the solar module according to the optimal type of interconnection.

In a further aspect, the invention relates to a solar cell arrangement, comprising a plurality of solar modules and an inverter, the solar modules being connected in series and connected to an input of the inverter. The solar cell arrangement is set up to set the solar cell arrangement to an operating point with an optimized operating current by means of the inverter. Furthermore, the solar cell arrangement is set up to provide a plurality of predetermined interconnection types for each solar module, according to which the solar elements can be interconnected within the respective solar cell module, and to carry out a sequential interconnection of the solar elements according to the respective predetermined interconnection types. In addition, the solar cell arrangement is set up to determine an efficiency parameter of the respective solar module for each connection according to one of the predetermined connection types. Furthermore, the solar cell arrangement is set up to determine an optimal connection type of the predetermined connection types in which the respective solar module has the best efficiency parameter and to connect the solar modules according to the respective optimal connection type. The working current is preferably also present in each of the solar modules at the same level, since the solar modules are preferably connected in series.

A solar element preferably designates a smallest unit in the solar cell arrangement, such as a smallest controllable and / or connectable unit. For example, a single solar cell can represent a solar element. Alternatively, a group of solar cells that is preferably electrically linked or connected in a dynamic manner can also be used. A solar cell group or group of solar cells is a number of solar elements or individual solar cells, which are connected either permanently (then referred to as a string) or dynamically (then referred to as a group) and can be controlled in this form as a solar element.

A bypass diode is preferably assigned to a solar cell group. This preferably offers an additional current path for photo currents that may not be covered by the dynamic interconnection of the solar cell groups
A solar module is an arrangement of solar elements, such as solar cells, solar cell groups and / or solar cell strings or solar cell strings. The solar module preferably comprises a prefabricated interconnection of solar elements in order to achieve a desired output voltage and / or a desired output current. A solar module is or comprises, for example, an arrangement of prefabricated solar cell groups or strings. All these solar elements can, for example, on the same level, ie solar cells with each other, solar cell groups or strings with each other or solar modules with each other, or on different levels, ie solar cells with solar groups or strings and / or solar modules or solar cell groups with solar modules or also on the same level , ie solar cells with solar cells, solar cell strings with solar cell strings, solar cell groups with solar cell groups and solar modules with solar modules are interconnected.

A solar cell arrangement is in particular an arrangement made up of several solar elements and / or solar modules. The solar cell arrangement can also have further elements, such as an inverter and / or a rectifier and / or a pole inverter. A solar cell arrangement can preferably be designed as a solar generator.

The interconnection of a solar module corresponds in particular to the interconnection of the solar elements of the respective solar module. The connection of the solar module or the solar elements can take place according to a plurality of connection types. The number of types of interconnection can preferably correspond to a number of combination or interconnection options for the solar elements of the respective solar module.

The predetermined types of interconnection are preferably specific, selected types of interconnection from the set of possible types of interconnection. In other words, the predetermined interconnection types preferably represent a subset of the possible interconnection types. The predetermined interconnection types can be selected from the possible interconnection types on the basis of different criteria. The predetermined types of interconnection are preferably provided in that the predetermined types of interconnection or the switching of switches in the respective solar module are stored in a memory unit and / or a control unit so that the predetermined types of interconnection can be called up and implemented.

A sequential interconnection of the solar elements in accordance with the predetermined interconnection types means that the solar elements are interconnected temporally one after the other in accordance with the individual predetermined interconnection types. For example, the interconnection of the respective solar elements can be changed such that the interconnection corresponds to the individual predetermined interconnection types one after the other. In other words, the interconnection of the solar elements of a solar module can be switched one after the other by the predetermined types of interconnection. The change between the various predetermined types of interconnection can take place without a waiting time between two successive types of interconnection or with a waiting time.

An efficiency parameter within the meaning of the invention is a determinable parameter, on the basis of which the efficiency of the solar cell system and / or one and / or more solar modules can be assessed. The efficiency parameter preferably corresponds to an electrical measured variable which can be measured on the basis of and / or by the solar cell arrangement. For example, the efficiency parameter can correspond to or be based on an output voltage and / or an operating current and / or a provided electrical power or output power of the solar cell arrangement and / or one or more solar modules. For example, the efficiency parameter can be proportional, in particular directly proportional, to an efficiency and / or the output voltage and / or an operating current and / or an output power of the solar cell arrangement and / or one or more solar modules. The efficiency parameter can be suitable for assessing the efficiency and / or the output voltage and / or an operating current and / or an output power of the solar cell arrangement and / or one or more solar modules at the time of the determination and / or cumulatively over a period of time before the determination.

Optimizing the type of connection of the solar module is to be understood as an at least local maximization of the efficiency and / or the output voltage and / or an operating current and / or an output power of the solar cell arrangement and / or one or more solar modules. In other words, the optimization need not necessarily aim at the achievement of the global maximum, but can be limited to the achievement of a local maximum. For example, the optimization of the interconnection can be limited to selecting the interconnection type from the predetermined interconnection types that has the greatest efficiency and / or the output voltage and / or an operating current and / or an output power of the solar cell arrangement and / or one or more solar modules among the predetermined interconnection types offers. The best efficiency parameter within the meaning of the invention is correspondingly the best value of the efficiency parameter that is achieved with the optimal type of interconnection among the predetermined types of interconnection.

The invention offers the advantage that the solar module and / or the solar cell arrangement can optimize itself independently and in this way can increase the yield of the solar module or the solar cell arrangement.

Furthermore, the invention offers the advantage that the duration of the optimization can preferably be limited to a certain amount in which the number of predetermined types of interconnection through which the respective solar module switches sequentially can be selected accordingly. This can optionally lead to the fact that the globally most suitable type of interconnection may not be selected, but rather that an only approximately optimal type of interconnection is selected. Because the optimization process, in which the solar module and / or the solar cell arrangement typically works with a low efficiency, but can be severely limited in time, for example to 10 μs, the overall efficiency can be improved. In particular, solar modules with a large number of solar elements can have a very large number of possible types of interconnection, so that sequential interconnection of the solar elements in accordance with all of these possible interconnection types would take a very long time. Because the sequential interconnection is restricted to a plurality of predetermined interconnection types, the time required for optimizing the interconnection can also be considerably limited. As a result, it can also be achieved in particular that the duration of the optimization is reduced and, accordingly, an optimization is possible at shorter time intervals. This short reaction time is particularly advantageous in the case of solar modules which are mounted on motor vehicles and are exposed to rapidly changing shading while driving. But solar systems shaded by moving wind turbine blades can also be found in practice. Such a short response time could also be advantageous for them.

The invention also offers the advantage that no communication channel between the solar modules and a control unit and / or an inverter is absolutely necessary for optimizing the interconnection of the solar modules and / or the solar cell arrangement, since the optimization can be carried out independently by the solar modules. Rather, a preferably predetermined by the inverter can Working current and / or a variation of the working current, which is preferably present at the same level in the solar modules, which are preferably connected in series, can be used to transmit signals from the inverter to the solar modules. This means that an additional communication channel can be dispensed with.

Furthermore, the invention offers the advantage that an existing solar cell arrangement can be provided with smart modules, preferably without having to make any further adjustments and / or retrofitting of the solar cell arrangement. In particular, a conventional inverter can be used in the solar cell arrangement and the smart module can still be optimized. In the context of the present invention, a “smart module” denotes such a solar module which is designed and set up to carry out a method according to the invention for optimizing the interconnection of the solar module. Examples of a hardware configuration of such a smart module are explained elsewhere in the description.

The predetermined types of interconnection preferably differ at least in that the solar elements of the respective solar module are interconnected in differently arranged solar cell strings and / or solar cell groups. For example, the solar elements can be interconnected in solar cell strings and / or solar cell groups of different lengths, i.e. with a different number of solar elements per string or group. The predetermined types of interconnection are preferably predetermined in such a way that the efficiency is optimized in the event of shading that is to be expected.

The predetermined types of interconnection are preferably predetermined as a function of different shading situations to be expected for the respective solar module. In other words, the predetermined types of interconnection are preferably reduced to a few types of interconnection which are relevant in practice and which are particularly preferably adapted to the expected shading of the respective solar module. As a result, the number of predetermined connection types to be switched through by the solar module can be reduced in order to also limit the time required for the sequential connection of the solar elements of the solar module. For example, a predetermined interconnection can interconnect the solar elements according to a specific geometry, which is adapted to the geometry of an expected or present shading situation or generates the maximum output voltage of the solar module in this.

The provision of the predetermined connection types preferably comprises the provision of at least 2, preferably at least 3, more preferably at least 4, even more preferably at least 5, much more preferably at least 6, most preferably at least 7 different predetermined connection types. Alternatively or additionally, providing the predetermined types of interconnection includes providing no more than 100, preferably no more than 50, more preferably no more than 30, much more preferably no more than 20, most preferably no more than 10 different predetermined interconnection types. This offers the advantage that the number of predetermined connection types and thus the time required for the sequential connection of the solar elements can be limited in accordance with the predetermined connection types. The number of predetermined types of interconnection is preferably adapted in terms of number and / or type to the shading situations to be expected.

The wiring of the solar modules is preferably optimized in such a way that there is no time overlap with the setting of the solar cell arrangement by means of the inverter. The setting of the solar cell arrangement by means of the inverter can preferably include determining an operating point with maximum power of the solar cell arrangement and can preferably be carried out by the inverter as standard and / or routinely and / or regularly. This offers the advantage that the setting or optimization of the solar cell arrangement by the inverter is not impaired by the optimization of the solar modules by the solar modules themselves. This avoids a superposition of effects and avoids the risk of a mismatching of the solar cell arrangement and / or a faulty and / or disadvantageous connection and / or a suboptimal operation of the solar cell arrangement. In this case, a solar module can be optimized in terms of time directly after the setting of the solar cell arrangement by means of the inverter, or there can be a time span or pause in between.

The optimization of the interconnection for each of the solar modules is preferably carried out independently by the respective solar module. This offers the advantage that no external control unit is required to control the optimization of the solar modules externally. Furthermore, this offers the advantage that each of the solar modules can adjust itself to the predetermined connection that is best suited for its own shading situation, regardless of the selected connections of the other solar modules. In particular, the solar modules can be set up to maximize or optimize an output voltage of the solar module for the working current specified by the inverter by the Solar elements of the respective solar module are connected according to the most suitable predetermined interconnection.

The wiring of the solar modules is preferably optimized for at least some, preferably all, of the solar modules at least partially at the same time. This offers the advantage that the period of time required for optimizing all solar modules can be reduced or even minimized. In addition, this offers the advantage that the reduction in the efficiency of the solar cell arrangement, which may occur during the optimization of the interconnection of the solar modules, can be minimized over time.

The optimization of the interconnection of the solar modules is preferably triggered by means of a trigger signal. This offers the possibility of initiating the start of optimizing the wiring of the solar modules in a targeted manner. Furthermore, this offers the advantage that preferably several or even all solar modules start optimization at the same time.

The inverter particularly preferably provides the trigger signal. This offers the advantage that no separate control unit needs to be provided in order to provide the trigger signal. The trigger signal is particularly preferably provided by the inverter in such a way that no (additional) communication line is required between the inverter and the solar modules.

Setting the solar cell arrangement to an operating point with an optimized operating current particularly preferably includes varying the operating current by means of the inverter. The trigger signal is provided based on the varying operating current. This offers the advantage that there are preferably no additional requirements to be placed on the inverter and its functionality. This in turn offers the advantage that a conventional inverter can preferably be used in the solar cell arrangement. For example, the inverter can use the fluctuations with the frequency of the power grid and / or a current fluctuation deliberately impressed on the working current to find the operating point. In a solar generator, in addition to direct voltage, there is also an alternating voltage, such as the US 2010157632A1 described by way of example, which provides the trigger signal for the Smart Module.

According to one embodiment, a method for optimizing an interconnection of a solar module in or from a smart module is carried out. According to one embodiment, a smart module or a module which is suitable for the method according to the invention can have several solar elements, as well as several switches for establishing and interrupting electrical connections between the solar elements and a control unit, the control unit being set up by means of the switches to interconnect the solar elements in different electrical arrangements, in particular dynamically interconnect them in different electrical arrangements during operation of the solar elements. The control unit preferably forms part of the solar module, so that, particularly preferably, no separate control unit is required in order to carry out the method for optimizing a connection of the solar module. The control unit can, for example, be integrated into the solar module or arranged outside the solar module and optionally attached to the solar module. A solar cell arrangement can have one or more smart modules and optionally also one or more other solar modules that are not designed as smart modules.

Unless otherwise stated, a solar module refers to a smart module in the following, unless expressly stated otherwise.

According to another embodiment, a solar cell arrangement can preferably comprise several solar elements and several switches for producing and interrupting electrical connections between the solar elements. The multiple switches are designed as diodes and can be controlled by an electrical voltage provided by the solar elements in order to interconnect the solar elements in different electrical arrangements or interconnections. According to this embodiment, the solar cell arrangement preferably has no control unit for optimizing the interconnection of the solar module. A combination of switches and diodes is also possible ( 38 )

The fact that the diodes can be controlled by an electrical voltage provided by the solar elements preferably means that they are controlled exclusively by the voltage provided by the solar elements. In particular, the switches designed as diodes preferably do not require any logic element and in particular no control unit in order to be controlled, but can only be controlled by the voltage of the solar elements. Preferably one or several diodes each assigned to a solar element and are controlled by the voltage provided by the respective solar element. whereby a very short reaction time to variable shading is achieved. For example, the switch, which is designed as a diode, can be controlled in such a way that the electrical resistance and / or the permeability of the respective diode depends on the voltage of the solar element to which the diode is assigned.

It is thus possible to combine the solar elements that have similar shading and in this way an optimized connection of solar elements with similar current characteristics can be made.

The solar elements in their dynamic interconnection then together form a solar generator, which can connect the individual solar elements in parallel or in series and thus optimize the power yield in a time-adjustable manner depending on the shading situation while simultaneously protecting against overload.

The optional control unit can have control logic for the switches. The control unit preferably comprises a microcontroller or microprocessor. The control unit makes it possible, by means of at least some of the switches, to be able to interconnect at least some of the solar elements in various different electrical arrangements during operation of the solar elements in at least two different ways.

The switches are preferably electrically and / or electronically and / or optically and / or electromagnetically controllable - preferably wire / cable-bound - switches (units). The actuators of the switches are preferably relay contacts, drain-source paths of (MOS) FETs or C-E paths of bipolar transistors. Further switches such as electromechanical switches (relays) or magnetic switches (transducers) are also preferably provided. The switches can preferably be actuated and switched over (switched on, switched off) several times by the electronic control unit.

The different electrical arrangements or interconnections of the solar elements include a series connection, a parallel connection or a combination of series and parallel connection (group connection), so that some solar elements are connected in series to one another and thus form a solar element group and other solar elements are connected in parallel to this group can. In this case, solar elements of approximately or, if possible, the same current intensity are preferably connected in series, preferably when the current intensity of the individual solar elements does not differ from one another by more than 10%. Solar elements are preferably connected in parallel if the output voltage of the different solar elements is as equal as possible, preferably not differing more than 10% from one another.

If solar elements that are unequal in terms of voltage are connected in parallel, equalizing currents arise which reduce the efficiency of the solar generator and, depending on the magnitude of the currents, can irreversibly damage it. If different solar elements are connected in series with regard to the current strength, some of the solar elements block and can be irreversibly damaged. Therefore, solar elements with the same temperature, the same efficiency and also the same lighting are preferably selected dynamically by the control unit belonging to a group and connected together.

The solar elements are preferably connected at any location, thereby achieving a high degree of freedom for taking into account different shading scenarios for individual solar elements. An interconnection of solar elements can particularly preferably be provided which is set up for expected shading scenarios or situations, i.e. the interconnection of solar elements is preconfigured according to the expected shading scenarios. The dynamic interconnection is therefore preferably set up according to the most common types of shading. The predetermined types of interconnection can therefore preferably be selected in such a way that they are each adapted to one of the most frequently occurring shading situations. As a result, switches are saved in comparison with an arbitrary interconnection.

The technical disadvantages of the state-of-the-art solar systems, those of the state of the art retrospectively (ie on the output side 20th ) have to be compensated by downstream electronics can be avoided by the present invention. Due to the variable electrical connection of the solar elements, the electricity yield is optimized on the input side and not on the output side. In addition, the properties that are optional in the prior art, such as emergency shutdown and intrinsic safety, are preferably designed on the input side and no longer as an add-on on the output side.

Particularly preferably, an nxm topology can be selected and individual solar elements can be freely configured with one another. If specific shading can be predicted based on the specific application, the solar elements can be preconfigured in the expected geometry and divided into solar elements or solar strings along the shading limits in order to connect these solar elements formed in this way. This makes it possible to dispense with additional work for a completely free interconnection and save unnecessary switching elements for this specific application of shading. This can be done in particular by providing predetermined types of interconnection.

The switches preferably comprise transistors and / or MOSFETS and / or power MOSFETs.

MOSFETs are metal-oxide-semiconductor field-effect transistors and power MOSFETs or high-voltage MOSFETs are a specialized version of a MOSFET that is optimized for conducting and blocking large electrical currents and voltages (up to several hundred amps and up to approx. 1000V, with a component volume of around one cubic centimeter).

Switching is preferably also possible in the current-supplying operating state of the arrangement, so that excessively high voltage at the switches / FETs up to approx. 2000 V can be avoided, which would otherwise lead to high RDSon (switch-on resistances) and power losses when using high-voltage MOSFETs.

The control unit preferably comprises a microprocessor and is set up to switch the switches in such a way that the electrical arrangement has several power / power levels, i.e. buses, to which the solar elements are connected depending on their current power / power yield.

In this way it is possible to combine the solar elements according to their electricity / power yield and to connect a bus that corresponds to this electricity / power yield.

• Unverschattete Solarelemente
• Vollverschattete Solarelemente und
• Teilverschattete Solarelemente entlang einer Schattenkante

The solar power of the solar elements is proportional to the lighting. Solar modules can be shaded by objects in the vicinity. These often have straight edges, which means that the shadows also have straight edges. In the simple case one can form three classes of shading:

• Unshaded solar elements
• Fully shaded solar elements and
• Partially shaded solar elements along a shadow edge

• High: 100% Strom = unverschattet
• Low: 30% Strom aufgrund der diffusen Hintergrundstrahlung mit 30% Anteil bei Vollverschattung
• Mid: 65±30% Strom durch eine Beleuchtung entlang einer Schattenkante

A division into three power buses is preferred:

• High: 100% electricity = unshadowed
• Low: 30% electricity due to the diffuse background radiation with 30% share in full shade
• Mid: 65 ± 30% current through lighting along a shadow edge

This means that there can be the same number of solar elements in a group; there can also be a different number of solar elements if they have a different level. N-current buses are preferably combined into one current bus.

A solar cell arrangement preferably comprises a connection for an intermediate consumer, preferably an inverter or a converter. Such an intermediate consumer can be connected via this connection.

An impedance converter with controllable or regulatable or self-adjusting optimal impedance depending on the (average) impedance of the source (s), especially after the MPPT Procedure (Maximum Power Point Tracking - Maximum Power Point Search (e.g. for the in US7256566B2 methods described).

Furthermore, it is preferred that the solar generator is operated as an inverter, which functions as a DC-AC / AC converter and converts the direct photo current of the solar generator into alternating voltage. For this purpose, an upstream rectifier can be provided in addition to an inverter. If the solar generator is already designed as an AC generator, the rectifier can preferably be omitted. Especially Preferably, an inverter operating mode is used with which an AC bus with medium frequencies of at least 50 kHz and above, preferably 100 kHz and above, can be generated. In the event of a breakdown in the solar element, for example contact after an accident, the current can flow through the skin and not through the heart. Preferably - so that the usual 50Hz output voltage inverters according to the state of the art can be used for the power grid feed - a rectifier is connected in front of the input of these inverters, which supplies the direct current usual in the state of the art for the 50Hz inverter. A preferred embodiment is an active rectifier, which has the advantage of higher efficiency compared to bridge rectifiers. Active rectifiers consist of transistor switches (NMOS) with a suitable control unit and their function replaces the diodes of the bridge rectifier.

In a further embodiment, the solar generator can dynamically interconnect the 50 Hz alternating current in the operating mode "island operation"
(Feed into a power island), while a possible "network operation" (feed into the public power grid) is described above.

In a further embodiment of the solar cell arrangement, the solar elements are arranged in an m x n, in particular a 2 x 2 or 3 x 3 topology, and the switches are arranged such that, with an m x n topology, n solar elements can be connected in series and thus form a string. A bypass diode is preferably connected in parallel to each of the n strings. Square topologies are preferably used, so that m = n.

In order to be able to connect solar element groups in parallel, they must preferably have the same voltage and thus the same number of cells. With ideal power sources, the number of cells is insignificant, but solar cells are power sources with intrinsic diodes connected in parallel. Therefore, a parallel connection of different numbers of solar cells can lead to equalizing currents and thus to a loss of yield, i.e. a reduction in efficiency. A division of the solar elements or solar cells into n x n groups is therefore preferred, since n cell strings or groups of equal length can be built up therefrom, which can be connected in parallel without disadvantage. In order to cover faults in the circuit, a bypass diode is preferably connected in parallel to each of these n cell strings.

A fourth diode is preferably switched via the input and output of the electrical two-pole of the solar element. This reduces the diode losses, as for example in the publications EP1045455B1 and US 6225793B1 described. This ensures the current flow through the solar element at all times during the dynamic interconnection, i.e. also during the switchover.

In a further embodiment the switches ( 32 geometric selection of solar cell groups) arranged so that the solar elements can be interconnected in groups in a horizontal direction, in a vertical direction, in a diagonal orientation or at a corner. For example, in a square arrangement of solar elements that are arranged in columns and rows, the solar elements can be interconnected in a row, in a column, in the diagonals or the solar elements arranged at corners in groups. Preferably, the same number of solar elements are always connected together in one group, so that when the diagonals are selected, parallel diagonals are also combined in one group. In a 3x3 matrix with elements 1 to 3.3, for example, it is possible to form three groups with a diagonal alignment, namely the middle diagonal consisting of the three individual elements 1, 2.2 and 3.3 as well as the adjacent solar elements 2.1, 3.1 and 3.2 and 1.2, 1.3 and 2.3. The orthogonal division to this is also conceivable, ie 1.1, 1.2, 2.1 / 1.3,2.2, 3.1 / 2.3,3.2,3.3. In the case of an alignment across a corner or an angular alignment, it is possible to form two groups of four solar elements each, for example solar elements 1, 1.2, 2.1, 2.2 and 1.3, 2.3, 3.1, 3.2, 3.3. A cell from the group with five cells is particularly preferably left uncontacted in order to avoid undesirable equalizing currents when 4 + 5 cells are connected in parallel and thus to have two groups of four groups each in a parallel connection. In the case of a horizontal alignment, the three rows are combined as a group (1.1, 1.2, 1.3 / 2.1, 2.2, 2.3 / 3.1, 3.2, 3.3) and in the case of a vertical alignment, the three columns ( 1 .1, 2.1, 3.1 / 1.2, 2.2, 3.2 / 1.3,2.3,3.3).

This can be carried out accordingly for smaller or larger square arrangements.

In a further exemplary embodiment, the switches are arranged in such a way that some or all groups can be interconnected in parallel ( 31 electrical selection of solar cell groups according to their possible maximum current. However, the actual current drawn is determined by the inverter. 31 and 32 together is referred to as a crossbar distributor circuit). If The groups consist of the same number of solar elements that are similarly shaded, they have the same maximum output current and are therefore similar. This allows the individual solar elements to be connected in series to form a group. If the output voltage of the different groups of solar elements is the same, they can be connected in parallel. It is thus possible, for example in the case of vertical shading of the first two columns 1 and 2, to connect the groups of the first column and the second column in parallel and these two then in series with the third (not shaded) group.

According to a preferred embodiment, a method for the dynamic interconnection of solar elements with switches is carried out via a control unit, whereby shading or a difference in performance between different solar elements ( 20th ) is determined, e.g. B. by a measurement by means of MPPT , the solar elements are classified into different groups according to their current performance or currently possible maximum output or the current lighting status and the solar elements of each group are interconnected. This dynamic interconnection of the solar elements during operation enables groups of similar solar elements to be identified and interconnected in such a way that the individual solar elements are not damaged and the overall arrangement of the solar elements is highly efficient.

• Unverschattete Solarelemente
• Vollverschattete Solarelemente und
• Teilverschattete Solarelemente entlang einer Schattenkante

Specifically, it is possible, for example, to select solar cells or solar elements that are adapted to the shade by defining several current classes / buses. Arrangements of solar elements can be shaded by objects in the vicinity. These often have straight edges, which means that the shadows also have straight edges. If you look at a partially shaded arrangement of solar elements, you can see

• Unshaded solar elements
• Fully shaded solar elements and
• Partially shaded solar elements along a shadow edge

• High: 100% Strom = unverschattet
• Low: 30% Strom aufgrund der diffusen Hintergrundstrahlung mit 30% Anteil bei Vollverschattung
• Mid: 65±30% Strom durch eine Beleuchtung entlang einer Schattenkante

Since the solar power of the cells is proportional to the lighting, a division into three power buses is preferred:

• High: 100% electricity = unshadowed
• Low: 30% electricity due to the diffuse background radiation with 30% share in full shade
• Mid: 65 ± 30% current through lighting along a shadow edge

If the electrical interconnection runs parallel to a shadow edge, the drop in performance is less than if the interconnection is perpendicular to it. In this case, a straight shadow affects all solar elements, even if they are only partially shaded. It is therefore preferably provided to combine the solar elements in groups of solar elements of the same type and then to interconnect them so that the highest possible efficiency of the arrangement of solar elements is achieved.

The conventional rigid electrical connection (StdT) is preferably adapted to the environment by arranging the arrangement of solar elements preferably horizontally or vertically. But even if the environment preferably creates vertically aligned shadow edges, there are slabs of snow on the solar modules in winter that create horizontal shadow edges. The electricity yield in winter is by no means low, as the solar modules are cold and have a high degree of efficiency and the radiation can come in with high radiation intensity despite the cold. Therefore, a decision for a connection direction (= geometrical alignment of the solar modules or solar elements) is only temporarily optimal. The claimed method provides a solution to achieve an optimized interconnection of the solar elements in these scenarios as well and thus on the one hand to protect the individual solar elements from damage and on the other hand to increase the efficiency of the arrangement of solar elements.

• Horizontal
• Vertikal
• Diagonal
• Diagonal um 90° gedreht (orthogonal)
• Winkelförmig bzw. über Eck

For example, the shading orientations to be expected from buildings are:

• Horizontal
• Vertical
• Diagonal
• Rotated diagonally by 90 ° (orthogonal)
• Angular or corner

The predetermined types of interconnection are preferably adapted to such geometries of the shading orientations. For example, a predetermined type of interconnection can be provided depending on the expected shading orientation.

A dynamic interconnection takes place through a spatial combination of solar elements, in particular solar cells, according to the geometrical shading alignment just shown. The geometric division of the cell matrix always takes place as parallel as possible to a shadow edge. This is the strategy for cell division horizontally, vertically, diagonally, orthogonally. The geometrical divisions just listed are ideal for shading with straight and parallel shadow edges. However, angular shadows have two orthogonal shadow edges. These are preferably divided up like diagonal shadows to keep the direction selection of the cells simple. In the case of angular shading, preference is given to a location-independent division into three power buses and, for the electrical interconnection, an electronic conversion of the power sources into voltage sources by means of three MPPT carried out.

• Reihenschaltung S1+S2+S3
• Parallelschaltung S1||S2||S3
• Gruppenschaltung
  • Variante 1: S1+(S2||S3) Abgekürzte Schreibweise: G1
  • Variante 2: S2+(S1||S3) " G2
  • Variante 3: S3+(S1||S2) „ G3

(Bereitgestellt durch die Schaltung nach 31)
Auf diese Weise wird ein Verfahren bereitgestellt, mit dem einzelne Solarelemente in einer Anordnung von Solarelementen, bevorzugt unter Einsatz von MPPT so zusammengeschaltet werden, dass die einzelnen Solarelemente vor irreversiblen Schäden, insbesondere durch Reihenschaltung von bezüglich der Stromstärke unterschiedlicher Solarelemente geschätzt werden und andererseits der Wirkungsgrad der Anordnung von Solarelementen erhöht wird.It is also preferable to combine the three power buses into one with a downstream circuit MPPT respectively. This method is used to turn the three current buses high, medium, low, ie the three two-pole (H, M, L-bus), which consist of the interconnected strings, into a single two-pole. This is done by optionally

• Series connection S1 + S2 + S3
• Parallel connection S1 || S2 || S3
• Group switching
  • Variant 1: S1 + (S2 || S3) Abbreviated notation: G1
  • Variant 2: S2 + (S1 || S3) "G2
  • Variant 3: S3 + (S1 || S2) "G3

(Provided by the circuit after 31 )
In this way, a method is provided with which individual solar elements in an arrangement of solar elements, preferably using MPPT are interconnected in such a way that the individual solar elements are estimated from irreversible damage, in particular by series connection of solar elements that are different in terms of current intensity and, on the other hand, the efficiency of the arrangement of solar elements is increased.

The solar elements of a group are preferably connected in series, particularly preferably some or all groups are connected in parallel.

• - wechselweises Umschalten der Polarität der gesamten Anordnung von Solarelementen, geeignet dazu einen Wechselstrom zu generieren;
  • - Generierung einer Wechselspannung größer 50 Hz, insbesondere 300 kHz;
• - Herstellung der Spannungsfreiheit der gesamten Anordnung der Solarelemente nach außen, d.h. eine Notabschaltung;
• - Notabschaltung bei Temperaturüberschreitung einer Temperaturüberwachung wenigstens eines der Solarelemente, insbesondere für den Brandschutz.

The solar elements are particularly preferably switched in such a way that at least one of the following functions is implemented:

• - Alternating switching of the polarity of the entire arrangement of solar elements, suitable for generating an alternating current;
  • - Generation of an alternating voltage greater than 50 Hz, in particular 300 kHz;
• - Establishing the absence of voltage of the entire arrangement of the solar elements to the outside, ie an emergency shutdown;
• - Emergency shutdown when the temperature exceeds a temperature monitoring of at least one of the solar elements, in particular for fire protection.

• - Monitoring von Betriebszustand, Strom, Spannung, Temperatur oder Hardwarecheck wenigstens eines der Solarelemente und der Elektronik für die dynamische Verschaltung (Selbstcheck);
• - Realisierung eines SMART-Moduls mit einer Menge an Solarelementen, die ein Modul bilden;
• - Lichtbogenerkennung und Modulabschaltung;
• - Diebstahlschutz und Standorterkennung;
• - Überwachung der Überschreitung der Betriebstemperatur und Einleitung von Blitzschutzmaßnahmen;
• - Optische und/oder akustische Kenntlichmachung, wenn das Modul defekt ist, sowie optional eine Fehlermeldung über einen bereitzustellenden Kommunikationskanal über Funk oder kabelgebunden.

A number of the solar elements preferably form a module and a microcontroller or programmable microprocessor realizes at least one of the following functions:

• - Monitoring of operating status, current, voltage, temperature or hardware check of at least one of the solar elements and the electronics for the dynamic interconnection (self-check);
• - Realization of a SMART module with a set of solar elements that form a module;
• - Arc detection and module shutdown;
• - Theft protection and location detection;
• - Monitoring of exceeding the operating temperature and initiation of lightning protection measures;
• - Optical and / or acoustic identification when the module is defective, and optionally an error message via a communication channel to be provided via radio or wired.

The plurality of switches are preferably designed as a diode matrix circuit. A preferred embodiment of a diode matrix circuit is, for example, in 40 shown. The diode matrix circuit is preferably designed in such a way that the solar elements are interconnected as an m × n matrix, as described above, and can be interconnected in different arrangements. For example, the matrix can be designed as a 3 × 3 matrix. The diode matrix circuit offers the advantage that a dynamic interconnection of the solar elements can take place, the interconnection or a change in the interconnection preferably taking place automatically by means of the diodes controlled by the voltage of the solar elements, without the intervention of a control unit being absolutely necessary. This offers the advantage that the dynamic interconnection can take place particularly efficiently and, in particular, in a passive manner. Furthermore, this offers the advantage that the dynamic interconnection and its change can take place particularly quickly, since no previous calculations by means of a control unit are required, which first determine the appropriate interconnection in view of the existing shading of the solar elements and then calculate a suitable interconnection of the solar elements .

The solar cell arrangement preferably comprises at least one pole changer, the solar cell arrangement being designed to connect the multiple solar elements at least partially in parallel by means of the pole changer ( 36 bottom left). In particular, the polarity reverser is designed to at least partially reverse the polarity of the solar elements within an m × n matrix, in particular within a 3 × 3 matrix, in order to switch between a parallel connection and a series connection of at least some of the solar elements. This offers the advantage that even if, for example, there is full shade, ie if all solar elements (of the mxn matrix) are shaded and the voltage of all solar elements is accordingly low, the solar elements can be interconnected in an advantageous arrangement. In the case of full shade, for example, the diode matrix circuit would lead to an arrangement of the solar elements in which all solar elements of the solar cell arrangement are connected in series, which can be disadvantageous for the current flow through the solar elements. By means of the pole reverser, the solar elements, such as the strings of a mxn matrix, can then be at least partially connected in parallel when there is full shade, so that a sufficient current flow through the solar elements can be maintained and in this way more efficient operation of the solar cell arrangement can be achieved than this with the series connection of the solar elements would be the case. For example, the solar elements of the solar cell arrangement can be arranged in a plurality of strings which, for example, are all connected in series when the solar elements are completely irradiated or illuminated, ie when the solar elements are not in the shade. The polarity reverser can then be used to reverse the polarity of one or more of the strings in the event of full or partial shading, so that the strings are no longer connected in series but at least partially, preferably completely, in parallel, which can be advantageous for partially or fully shaded conditions.

According to a preferred embodiment, the solar cell arrangement has a first string of solar elements or solar cells and a second string of solar elements or solar cells connected in parallel to the first string, the second string having a smaller number of solar elements or solar cells than the first string. (Circuit according to 37 , implicitly provided by the circuit according to 34 bottom left) Furthermore, the solar cell arrangement according to this embodiment has a diode which is connected in series with the second strand and in parallel with the first strand. This offers the advantage that a parallel connection of several strings is made possible, which have a different number of solar elements, without the different number of solar elements or solar cells causing a compensating current between the arms of the parallel connection or at least reducing such a compensating current.

One field of application for dynamic interconnection is increasing the yield of solar systems or solar cell arrangements. Another field of application is the thermal relief of bypass diodes. This makes use in difficult environments, such as in a solar facade, sensible, as this way, undesired heating of the air space behind the cold facade can be reduced or avoided. This can help in particular to avoid reaching and / or exceeding a limit temperature at which damage to the solar facade can occur, for example at or above temperatures of 75 ° C or 90 ° C. For example, reaching and / or exceeding such high temperatures can result in bypass diodes being insufficiently cooled and thus being damaged. This risk can be reduced by an optimized dynamic interconnection, since the bypass diode current can preferably be reduced considerably and, particularly preferably, can be essentially completely eliminated. For example, it can be achieved in this way that only the reverse current of the diode flows in the bypass diodes, which is typically in the range 10E-3 to 10E-6 amperes.

Preferably, a conventional electronic circuit, such as in the US 2014 / 0375145A1 described, can be used to operate a solar cell arrangement with additional electronics for dynamic interconnection, for example with a diode matrix circuit and / or a pole-reversing circuit. The circuit is preferably designed to be able to provide sufficient electrical energy for the additional electronics of the solar module even when a solar module is fully shaded.

For example, a circuit according to FIG US 2014 / 0375145A1 come to use, as for example in the figure of the summary of US 2014 / 0375145A1 shown. If the strings V1 to V3 are each 20 cells long, the voltage across a cell string is 12V, since the voltage of a cell in the maximum power point is usually 0.6V. The three strings V1 to V3 thus comprise a total of 60 cells. A PMOS or PNP transistor could be used as switch P. An electromechanical relay could also be used. The switch P could alternatively also be between the diode D1 and be attached to the cell string V1. If the voltage between contacts 2 and 3 falls below a threshold value, then switch P can be opened, whereby the voltage at D4 with respect to contact 3 rises again or at least does not fall below a threshold value that can be set within a wide range (3V to 30V). In addition, auxiliary energy is stored in the capacitor C1, so that you have several seconds to minutes to initiate the switching process of the switch P.

It goes without saying that the embodiments and features explained above and below are to be viewed not only as being disclosed on their own and in the combinations explained in each case, but also in other technically feasible combinations. In particular, the preferred features, which are disclosed, for example, with reference to a solar cell arrangement having a control unit, are also to be regarded as disclosed with reference to an embodiment with switches configured as diodes or with a diode matrix circuit.

Preferred embodiments and examples are explained in more detail below with reference to the drawings.

• 1 in einer schematischen Darstellung eine Solarzellenanordnung 1 gemäß einer bevorzugten Ausführungsform;
• 2 in einer schematischen Darstellung ein Gebäude 100, welches auf dem Dach mit einer Solarzellenanordnung 1 gemäß einer bevorzugten Ausführungsform versehen ist;
• 3 beispielhaft einen Verlauf der zu erwartenden, relativen Ertragssteigerung für eine Solarzellenanordnung gemäß einer bevorzugten Ausführungsform mit einem Smart-Modul 27a und zwei Standard Solarmodulen 27b, wie beispielsweise auf einer Seite des in 2 dargestellten Gebäudes, und mit einer Schaltung, wie mit Bezug auf 38 erläutert;
• 4A und 4B in schematischen Darstellungen zwei verschiedene Anordnungen von Solarzellenanordnungen 1 mit jeweils sechs Solarmodulen 27;
• 5A und 5B in schematischen Darstellungen jeweils eine Solarzellenanordnung 1, bei welchen eine Synchronisierung der Solarmodule 27 vorteilhaft ist;
• 6 ein Solarzellenstring nach StdT mit Bypassdiode,
• 7 ein teilverschattetes Solarmodul mit 3 Solarzellenstrings mit Bypassdioden,
• 8 Schaltsymbol und Ersatzschaltbild einer Solarzelle,
• 9 eine Leistungs- und Spannungskurve eines teilverschatteten Moduls,
• 10 eine Leistungs- und Spannungskurve eines unverschatteten Moduls,
• 11 einen Solargenerator mit parallel geschalteten Solarzellenstrings, davon ein String durch eine defekte Bypassdiode elektrisch verkürzt,
• 12 die Arbeitspunkte für einen Rückstrom unter und ohne Last, für einen Solargenerator nach 11 (OP1=Normalbetrieb, OP2=Rückstrom durch defekte Bypassdiode),
• 13 eine Solaranlage mit einer seriellen Diode pro Solarmodulstring (Stringdiode) zur Vermeidung von Rückströmen,
• 14 eine Gruppenschaltung,
• 15 eine Solarzellenanordnung mit weiteren Dioden (StdT nach 5 in WO2012163908 ),
• 16 Solarmodule in Serienschaltung nach dem Stand der Technik,
• 17 eine dynamische Serienschaltung von Solarzellen innerhalb eines Solarmoduls mit gleichem Maximalstrom und Aufteilung in 3 unterschiedliche Strom niveaus, resultiert in ein unpraktisches Solarmodul mit 6 Anschlussleitungen
• 18 ein Solarmodul mit Zusammenfassung der 3 Strombusse von 17 in einen Strombus durch MPPT mit praxisgerechten, nur noch 2 Anschlussleitungen,
• 19 eine Reihenschaltung von Solarmodulen von der Art von 18,
• 20 eine starre Reihenschaltung von Solarmodulen mit externen MPPTs nach dem Stand der Technik,
• 21 eine horizontale Abschattung mit dynamischer Verschaltung, mit zusätzlichen Bypassdioden in Dickmannschaltung siehe US Patent No. 6225793 ,
• 22 einen Schaltplan für eine Simulation einer Reihenschaltung von 3 Solarmodulen nach dem StdT mit einer zeitlich wandernden Verschattung über ein Modul dieser Reihe sowie einem Diagramm des Ertragsverlaufs,
• 23 ein Beispiel für eine zeitliche Abfolge einer Abschattung, (Vergrößerung des Diagramms nach 22) für Solarmodule nach dem StdT,
• 24 die Abfolge der Abschattung vergrößert, für Solarmodule nach dem StdT sowie in verschiedenen dynamischen Verschaltungen nach 21,
• 25 eine Leistungskurve einer 3x3 Solarzellgruppe,
• 26, ein Beispiel für eine zeitlich veränderliche vertikale Verschattung,
• 27 ein Beispiel für eine zeitlich veränderliche diagonale Verschattung
• 28a ein Beispiel für eine aus 27 resultierende elektrische Zusammenfassung (Reihenschaltung von gleichen Strömen I_n) von Solarzellen welche analog 21 elektrisch verschaltet werden,
• 28b Stromgruppen für eine orthogonale diagonale Verschattung,
• 29 ein Beispiel für eine orthogonale, winkelförmige Verschattung,
• 30 MOS-Schalter (eigentlich Schaltzeichen für allgemeine spannungsgesteuerte Schalter),
• 31 ein Verschaltungskonzept für die dynamische Verschaltung,(Kreuzschienenverteiler (Seriell, Parallel, Alle Gruppenschaltungen G1..G3) für 32), welche die Stromgruppen 11, I2 und I3 elektrisch gemäß 21 zusammenfasst,
• 32 bevorzugte Schalteranordnung zur geometrischen Auswahl von Solarzellgruppen entlang von Schattenkanten in einer 3x3-Matrix, passend zu den Verschattungsformen horizontal 21, vertikal (nicht gezeigt), diagonal, winkelförmig 27 und orthogonal diagonal, winkelförmig 29 Hiermit erfolgt die Geometrische Auswahl von Solarzellgruppen womit die Einteilung in die Stromgruppen 11, I2 und I3 erfolgt,
• 33 eine Anordnung von Solarelementen gemäß einer bevorzugten Ausführungsform mit einer vereinfachten Gruppenschaltung (nur G1 und G3),
• 34 Vereinfachte Gruppenschaltung (nur G1 und G3),
• 35 verschiedene Anordnungen von Solarzellgruppen entlang von Schattenkanten Q=Quer=orthogonal diagonal,
• 36 Polwenderschaltung (links unten in 36) nicht zu verwechseln mit dem ausgangsseitigen Polwender rechts unten in der Schaltung eine Schaltung von Zellstrings in Parallelschaltung mit optional unterschiedlicher Anzahl von Solarzellen),
• 37 eine Schaltung von Zellstrings in Parallelschaltung mit unterschiedlicher Anzahl von Solarzellen),, resultierend aus der vereinfachten Gruppenschaltung nach 34,
• 38 eine Diodenmatrixschaltung, kombiniert mit der Polwenderschaltung 36,
• 39 Ausgangsseitiger Polwender (z.B. für AC-Module), geeignet für die Schaltungen nach 31, 34, 36, sowie 38,
• 40 eine Diodenmatrixschaltung gemäß einer bevorzugten Ausführungsform,
• 41 bis 47 Solarzellenanordnungen mit bevorzugten Zellaufteilungen für 120VDC Systemspannung und mit unterschiedlicher Anzahl von Solarzellen in 3 x 3 Matritzen,
• 43 linker Teil der Schaltung von 45,
• 44 Linker Teil der Schaltung von 46,
• 45 Rechter Teil der Schaltung von 43,
• 46 Rechter Teil der Schaltung 44,
• 47 Drei in Reihe geschaltete Smart Solarmodule ergeben eine bevorzugte Systemspannung von 120VDC mit einer bevorzugten Aufteilung in 3x3 Solarzellgruppen, bestehend aus der Reihenschaltung von jeweils 4 Zellen vertikal mit 2 Zellen horizontal. Diese Aufteilung ist besonders für 72 Solarzellen Standard-Solarmodule geeignet,
• 48 Polwenderschaltung, Ausschnitt von 36.

Show it:

• 1 in a schematic representation a solar cell arrangement 1 according to a preferred embodiment;
• 2 a schematic representation of a building 100 which is on the roof with a solar array 1 is provided according to a preferred embodiment;
• 3 an example of a course of the expected, relative increase in yield for a solar cell arrangement according to a preferred embodiment with a smart module 27a and two standard solar modules 27b , such as on one side of the in 2 illustrated building, and with a circuit as with reference to 38 explained;
• 4A and 4B in schematic representations two different arrangements of solar cell arrangements 1 with six solar modules each 27 ;
• 5A and 5B in schematic representations each a solar cell arrangement 1 , in which a synchronization of the solar modules 27 is advantageous;
• 6th a solar cell string according to StdT with bypass diode,
• 7th a partially shaded solar module with 3 solar cell strings with bypass diodes,
• 8th Circuit symbol and equivalent circuit diagram of a solar cell,
• 9 a power and voltage curve of a partially shaded module,
• 10 a power and voltage curve of an unshaded module,
• 11 a solar generator with solar cell strings connected in parallel, one of which is electrically shortened by a defective bypass diode,
• 12 the operating points for a reverse current under and without load, for a solar generator according to 11 (OP1 = normal operation, OP2 = reverse current through defective bypass diode),
• 13 a solar system with a serial diode per solar module string (string diode) to avoid reverse currents,
• 14th a group connection,
• 15th a solar cell arrangement with further diodes (StdT according to 5 in WO2012163908 ),
• 16 State-of-the-art solar modules connected in series,
• 17th A dynamic series connection of solar cells within a solar module with the same maximum current and division into 3 different current levels results in an impractical solar module with 6 connection lines
• 18th a solar module with a combination of the 3 power buses from 17th into a power bus MPPT with practical, only 2 connection cables,
• 19th a series connection of solar modules of the type of 18th ,
• 20th a rigid series connection of solar modules with external MPPTs according to the state of the art,
• 21st horizontal shading with dynamic interconnection, with additional bypass diodes in Dickmann circuit see US Patent No. 6225793 ,
• 22nd a circuit diagram for a simulation of a series connection of 3 solar modules according to the StdT with a time-shifting shading over a module of this series as well as a diagram of the yield curve,
• 23 an example of a time sequence of shading, (enlargement of the diagram according to 22nd ) for solar modules according to the StdT,
• 24 the sequence of shading increases, for solar modules according to the StdT and in various dynamic interconnections according to 21st ,
• 25th a performance curve of a 3x3 solar cell group,
• 26th , an example of vertical shading that changes over time,
• 27 an example of diagonal shading that changes over time
• 28a an example of one out 27 resulting electrical combination (series connection of equal currents I _n ) of solar cells which are analog 21st be electrically connected,
• 28b Stream groups for orthogonal diagonal shading,
• 29 an example of an orthogonal, angular shade,
• 30th MOS switch (actually a circuit symbol for general voltage-controlled switches),
• 31 an interconnection concept for dynamic interconnection (crossbar distributors (serial, parallel, all group connections G1..G3) for 32 ), which the current groups 11, I2 and I3 electrically according to 21st summarizes,
• 32 Preferred switch arrangement for the geometrical selection of solar cell groups along shadow edges in a 3x3 matrix, matching the shadow shapes horizontally 21st , vertical (not shown), diagonal, angular 27 and orthogonal diagonal, angular 29 This is used to geometrically select solar cell groups, which are divided into current groups 11, I2 and I3,
• 33 an arrangement of solar elements according to a preferred embodiment with a simplified group circuit (only G1 and G3),
• 34 Simplified group switching (only G1 and G3),
• 35 different arrangements of solar cell groups along shadow edges Q = cross = orthogonal diagonal,
• 36 Pole reversing circuit (bottom left in 36 ) not to be confused with the output-side pole changer at the bottom right in the circuit a circuit of cell strings in parallel with optionally different numbers of solar cells),
• 37 a connection of cell strings in parallel with different numbers of solar cells) ,, resulting from the simplified group connection according to 34 ,
• 38 a diode matrix circuit combined with the pole reverser circuit 36 ,
• 39 Output-side pole inverter (e.g. for AC modules), suitable for the circuits according to 31 , 34 , 36 , such as 38 ,
• 40 a diode matrix circuit according to a preferred embodiment,
• 41 to 47 Solar cell arrangements with preferred cell divisions for 120VDC system voltage and with different numbers of solar cells in 3 x 3 matrices,
• 43 left part of the circuit of 45 ,
• 44 Left part of the circuit of 46 ,
• 45 Right part of the circuit of 43 ,
• 46 Right part of the circuit 44 ,
• 47 Three smart solar modules connected in series result in a preferred system voltage of 120VDC with a preferred division into 3x3 solar cell groups, consisting of the series connection of 4 cells vertically with 2 cells horizontally. This division is particularly suitable for 72 solar cells standard solar modules,
• 48 Pole reverser circuit, excerpt from 36 .

1 shows a schematic representation of a solar cell arrangement 1 according to a preferred embodiment, which is designed as a solar generator. The solar cell arrangement 1 has several solar panels 27 that are electrically connected in series. The solar modules can each be designed as a smart module or as a conventional solar module, wherein the solar cell arrangement can have exclusively smart modules or both smart modules and conventional modules.

The solar modules connected in series 27 are through a rectifier 46 with the input of an inverter 40 connected.

The inverter 40 is set up for this purpose, the solar cell arrangement 1 set to the operating point with optimized or maximum operating current. The working point is also called the Maximum Power Point ( MPP ) designated. This causes the working current in the solar cell array 1 through the inverter 40 given. Due to the series connection of the solar modules 27 in the solar cell array 1 is the working current that goes into all solar modules 27 is present, essentially identical and through the inverter 40 certainly.

The inverter 40 is preferably set up to check the working point or the working current at regular time intervals and adjust it if necessary. For example, the time span between the checks and adjustments to the operating point can be between 30 seconds and 5 minutes, with shorter or longer time intervals also being advantageous. In principle, a weighing up is necessary for a suitable choice of the time period between the checks and optional adjustments to the operating point, since a rapid adjustment of the operating point can lead to a rapid increase in the efficiency of the solar cell arrangement, but the checking and adjustment itself takes place during the period of the inspection and adaptation leads to a reduced efficiency of the solar cell arrangement. To check and adjust the operating point, the inverter can vary the operating current and determine the effects of the variation in the operating current on the efficiency or output power of the solar cell arrangement or the solar generator.

The one for optimizing the interconnection of a solar module 27 The time required can in particular depend on the number of predetermined types of interconnection and / or on the switching speed of the switches in the solar module 27 depend. One example is the optimization of the interconnection of a solar module 27 realizable within a period of 10 µs and possibly advantageous. Adjusting the solar cell arrangement 1 on the other hand, the operating point typically takes about 1 ms to about 4 ms. The optimization of the interconnection of a solar module 27 can thus be done much faster than the setting of the operating point by the inverter. The time span or waiting time between two optimizations of the interconnection of a solar module is preferably 27 several grid half-waves, causing a fault in the inverter 40 and the associated loss of efficiency can be reduced.

Based on the variation of the operating current during the checking and adjustment of the operating point by the inverter 40 the solar modules can recognize that the checking and adjustment of the operating point is taking place. In order to avoid a superimposition of effects and the resulting disruptive influences on the setting of the operating point, it is advantageous if the solar modules 27 are set up to carry out the optimization of the interconnection of the solar modules while the operating point is being set by the inverter 27 to stop.

However, it can be advantageous to optimize the wiring of the solar modules 27 to begin immediately after or shortly after the end of the setting of the operating point in order to increase the probability that the optimization will be completed before the beginning of the next setting of the operating point. For example, the start of optimizing the interconnection of the solar cells can be offset by a predetermined period of time from the determined beginning of the setting of the operating point, the predetermined period of time being selected in such a way that the setting of the operating point after the predefined period of time is very likely or certain is finished. Alternatively or additionally, the end of the setting of the operating point can also be determined, for example based on the occurrence or non-occurrence of a variation in the operating current, and the optimization of the connection of the solar elements of the solar modules can then be started when the end of the setting of the operating point has been determined.

The solar modules preferably lead 27 the optimization of the interconnection of your solar elements independently. For example, any solar module 27 have their own control unit for this purpose. Preferably, no separate control unit is necessary, which would coordinate the optimization of the interconnection of the solar modules of the solar cell arrangement externally. Rather, the solar modules 27 preferably carry out the optimization yourself and independently of the optimizations of the other solar elements. The optimizations are preferably carried out by the respective solar modules 27 carried out at least partially in parallel, ie at the same time. This has the advantage that the time required to optimize all solar modules that are designed as smart modules can be minimized.

By setting the operating point on the one hand and independently optimizing the solar modules on the other hand, the efficiency of the solar cell arrangement can therefore be increased. Since the solar modules can carry out the optimization independently, a separate control unit and a communication line connected to it from the separate control unit to the solar modules is not absolutely necessary, although this may be present according to other embodiments.

2 shows a building in a schematic representation 100 which is on the roof with a solar array 1 is provided according to a preferred embodiment. The solar cell arrangement 1 has a total of six solar modules 27 on which on the roof of the building 100 are arranged and are preferably oriented to the south. Here are the two interior solar modules that are adjacent to the dormer 27a as smart modules 27a formed while the four external solar modules 27b than conventional solar modules 27b are trained. Such an arrangement offers the advantage that for the internal solar modules 27a In the course of a day, changing shading is to be expected, since the adjacent dormer window partially shading the solar modules inside, depending on the angle of incidence of the sun's rays 27a caused. As for the external solar modules 27b If such partial shading is not to be expected due to the dormer window, it can be economically advantageous to use this as conventional solar modules 27b to design. The predetermined types of connections for the solar modules 27a can be predetermined in such a way that this is an optimization of the respective solar module 27 for the expected shape and / or the expected course of the shading through the dormer window, and the output voltage of the respective solar module in the respective expected shading situations 27a optimize.

As in 2 shown, so can in a solar cell arrangement 1 conventional solar modules 27b and smart modules 27a be combined.

3 shows an example of a course of the expected, relative increase in yield in percent (y-axis) compared to shading in any units (x-axis) (here short-circuit current I _{sc of} a shaded solar cell in amperes according to StdT 9A = unshaded, 0 to 3A = fully shaded ) for a solar cell arrangement 1 with three smart modules 27a compared to a solar cell arrangement with three conventional solar modules 27b . This shows that with partial shading, a relative increase in the yield compared to a solar cell arrangement with exclusively conventional solar modules of up to 23% can be achieved, which initially increases with decreasing shading from approx. 18% to approx. 23% and then further falling shading drops to 0.

The 4A and 4B show in schematic representations two different arrangements of solar cell arrangements 1 with six solar modules each 27 . Of the six solar modules 27 are four than conventional solar panels 27b trained and two as smart modules 27a . The solar cell arrangement 1 has two module strings, of which each module string has two conventional solar modules 27b and a smart module 27a which are connected in series. According to the in 4a The embodiment shown is each module string to its own inverter 40 connected so that the solar cell array 1 a total of two inverters 40 having. According to the in 4B The embodiment shown are both strings on the same inverter 40 connected, the inverter having an independent input for each string.

The 4A , 4B , 5A and 5B show options for interconnecting the solar generator from 2 . , in which 5A is the worst variant in terms of shading.

Various aspects relating to solar modules, solar cell arrangements and smart modules are explained below for the purposes of explanation. The explained solar modules and solar cell arrangements and smart modules can preferably be used in accordance with preferred embodiments.

State-of-the-art solar modules are designed for ideal installation in a solar system. This includes the lack of shading, a homogeneous orientation in one direction and adequate ventilation. If this is not the case, there will be significant yield losses and electrical and thermal stress for the system.

In free-standing solar systems, the lighting situation can be improved by mechanically tracking the position of the sun with the solar cells or solar modules using so-called trackers. In solar modules that are attached to the building (BAPV Building Attached Photovoltaics such as rooftop systems and BIPV Building Integrated Photovoltaics such as solar facades) this is not possible or only with difficulty. When installing on a building envelope, shading is to be expected for geometric reasons (protrusions, bay windows, chimneys, antennas, etc.). According to the state of the art, shaded parts of the building envelope are therefore often left out. This problem is solved according to the invention in that, instead of mechanical tracking, a concept for electrical tracking of the system is presented. Moving and therefore error-prone parts can thus be avoided.

The present presentation focuses on crystalline solar cells, as the situation there is the most problematic due to the high currents.

Solar modules consist of a series connection of solar cells. Solar cells are not a voltage source, but a current source. A solar cell supplies an electric current proportional to the light irradiation. Ideal power sources have an infinitely high output voltage

According to the usual rules of electrical engineering, power sources would have to be connected in parallel. However, since the solar cells only have a low real output voltage of around 0.6V at the operating point of maximum power ( MPP = Maximum Power Point), they are still connected in series (as a string) in order to achieve technically usable input voltages. The output voltage of such a series connection of solar cells may currently be up to 1500 VDC. The same applies to individual solar modules, which are often connected in series in order to supply a voltage that an inverter can usefully convert into a grid-compatible alternating voltage.

Is a solar cell in this series - consisting of z. B. 2000 solar cells - shaded, this not only supplies a small amount of current, but worse, it also blocks the large flow of current from the remaining unshaded solar cells. It's more likely to break than give in to the flow of electricity. This is an essential property of power sources. However, the output voltage of the unshaded cells is high enough to force the current through the shadowed cell. In order to protect the shaded solar cell from self-destruction, bypass diodes are inserted in sections into the series circuit, which conducts the "excess" current around the shaded solar cell.

Such a section of a solar cell string ( SZS ) designated arrangement of solar cells, comprising an electrical series connection of 20th Solar cells SC is in 6th shown. The bypass diode is located on the right in the circuit diagram D1 .

State-of-the-art SZS consist of 20th or 24 solar cells. If the solar cells are connected in series, the technically best solution in terms of energy yield is to provide each solar cell with a bypass diode. In order to lower the purchase price of the solar module, however SZS used with a bypass diode ( 6th ). In the case of a bypass, the shaded cell sees the voltage of all the remaining solar cells of the SZS plus the forward voltage of the bypass diode. The number of solar cells in one SZS is therefore limited by the reverse voltage of the solar cells used. Solar modules made of crystalline solar cells are therefore z. B. from 3 SZS with 3x20 = 60 or 3x24 = 72 cells.

7th (Source: wdwd - Eigenes Werk, CC-BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39303681) shows a solar module consisting of three solar cell strings SZS (PC1, PC2, PC3). in a standard solar module. The middle one SZS (PC2) is shaded and the stream I. therefore flows through the bypass diode D2.

From a fire protection point of view, solar cells are a source of danger: Solar cells or modules are sources of ignition, as electrical energy flows in them and at the same time they bring with them the fuel in the form of their organic content in the form of embedding and backing foils. They are approved purely in accordance with electrotechnical standards and, as a rule, they do not have a general building authority approval - due to the fact that the residual load-bearing capacity and fire class are usually not tested. This complicates the structural approval as a solar facade or solar roof with integrated solar modules (BIPV)

The electrical characteristic of a solar cell can be obtained from electrical equivalent circuit diagrams. There are more or less detailed equivalent circuits for a solar cell. The simplest of all equivalent circuit diagrams, as in 8th (Source: By Degreen from the German language Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7724909). The circuit symbol is shown on the left and the equivalent circuit diagram consists of a light-controlled current source and a diode for voltage limitation. As a result, an illuminated solar cell short-circuits its own photocurrent when idling. The output voltage of the solar cell corresponds to the forward voltage US of the diode.

With partial shading, as in 9 shown, despite the bypass diode, there is a strong drop in power in the solar module, since the solar cells (power sources) are connected in series and not in parallel. It's the performance curve P (MPP) and voltage curve U (MPP) for the situation 7th shown. The maximum power is withdrawn from the solar module when the lighting-dependent maximum current I _{MPP is} taken from the shaded solar module group PC2. If the load current is increased through the load resistor RL, the output voltage and thus the power decrease significantly. For the short-circuit currents of the solar cell groups PC1 and PC3, 9A was assumed and for the shaded solar cell group PC2 30% of 9A. Due to the diffuse background radiation of around 30% light intensity, the current from PC2 does not drop to zero.

In comparison shows 10 the voltage and power curve of the unshaded solar module. Only the voltage and power curve of the shaded module is shown.

It turns out that with the solar cell model used, the maximum power in 9 only 30% of the unshaded maximum output 10 amounts to, although only one SZS (PC2) is in shadow. It can therefore be determined: The loss of yield due to shading can be considerable despite the bypass diode, even if only one cell (or SZS ) is shaded. Without an invoice, just by looking at it, one might be tempted to assume that the output power is still between 66% and 77% of the maximum power, which corresponds to the proportion of the “failed” solar cells. Here, however, the calculation only gives about 34% of the maximum output.

The reason for the sharp drop in yield with partial shading is the rigid electrical series connection of the solar cells within the solar modules and the voltage drop at the bypass diode D2 in, which increases with the current 7th as well as the voltage drop on the electrical wiring of the solar module.

The bypass diodes can be located in the solar junction boxes that are firmly glued to the solar module. Due to the waste heat concept of the solar junction boxes according to the approval standards EN 50548 or EN 61730, a so-called thermal runaway (thermal runaway with self-destruction) of the bypass diodes can occur because the temperature dependency of the diode reverse current is not taken into account and only with the standard EN 62979 : Received attention in 2016.

After a thermal runaway, the bypass diode is interrupted or defective in the short circuit. In the event of an interruption and partial shading, the affected cell group can then be irreversibly destroyed.

In the event of a short-circuiting defect in the bypass diode and partial shading, it depends on the operating situation whether the junction box with the defective bypass diode is thermally overloaded. The short circuit of the damaged bypass diode is not perfect and often generates three times the waste heat of an undamaged diode in bypass operation.

11 (Source: SMA http://files.sma.de/dl/7418/Rueckstrom-UEN083010.pdf) shows a solar generator, consisting of SMS (solar module strings) connected in parallel, which are connected to an inverter (right). Operation takes place with a short-circuiting bypass diode.

During operation, the inverter will draw power from the solar module strings (SMS) running at full voltage, as in 12 shown, so that relatively little current flows in the SMS that has been electrically shortened by the short circuit. If the inverter is switched off, however, a considerable compensating current flows in the form of reverse current in the solar system, which, according to the state of the art, cannot be switched off without additional electronics (solar module string diode). The inverter is switched off in part by the network operator of the public power grid. In this case, the solar power supplier has no influence.

In 12 the operating points reverse current with load (operating point OP1 => Irev = 9A) and without load (operating point OP2 => Irev = 27A) are shown.

In particular, if the solar system is a solar facade, a short circuit of modules in the event of an accident is conceivable (e.g. if a car crashes with the solar facade). The flow of equalizing currents can make rescue measures difficult or even impossible as long as the sun is shining.

Such errors can be countered with string diodes, as described in 13 , which represents a solar system with one string diode per string, is shown.

However, string diodes cause a loss of energy during normal operation of the system because they heat up and it is not certain whether their function is monitored in practice. I.e. they can fail conductive and the failure is hardly recognized in normal operation due to a slight decrease in the yield of the system. In the event of a conductive failure, the solar system continues to deliver electricity, but increased waste heat from the string diode, which could be detected, for example, by monitoring the temperature of the string diode, and in the event of an interrupting failure, there is no current flow, which can easily be recognized by a drop in performance of the solar system. In order to save costs, string diodes are not always installed.

Another possible fault in solar systems is the failure of solar connectors and the loss of cable insulation due to marten bites. In the event of this fault, an arc can form that burns for a long time (around 30 minutes) and does not go out. In the USA, such situations are encountered with the use of arc detectors, which are required by NEC 2014 (National Electric Code 2014 and following). Arc detectors are rarely used in Europe at the moment.

Due to the lack of a voltage zero crossing, direct current arcs do not extinguish as easily as alternating current arcs. Therefore, a solar module with an AC voltage output has advantages in this regard.

The type of cable routing within the solar modules results in an area in which voltages can be induced by magnetic fields. In nature, such magnetic fields are generated by lightning near-field strikes, which can then pre-damage the bypass diodes and other system parts. Consequential errors can then be arcs in the solar system if the sun shines again afterwards.

In the following, an electrical circuit concept is proposed that avoids the above-mentioned disadvantages or represents a more cost-effective solution than existing systems.

Depending on the lighting situation of the solar modules, the circuit concept switches dynamically adapted series, parallel and group connections of the solar cells within a solar module and generally also of solar modules within solar generators and generally the interconnection of voltage-limited power sources.

This means solar cells that are connected in series at one point in time can be switched dynamically and connected in parallel at another point in time. Likewise vice versa and optionally optionally for more than two solar cells. The latter enables dynamic group switching.

The term solar element here includes a solar cell as the smallest unit. Alternatively, a dynamically and electrically linked group of solar cells can be meant, which z. B. form a solar module. A solar module, which consists of several strings, or groups of strings and solar cells, can also form a solar element. Statements that are made for solar cells or modules are generally also valid for the other element. The electrical connection can, but does not have to be, made by electrical or electronic switches. A magnetic link by means of transformers with multiple windings and also with the help of transducers is also conceivable, along with other physical effects. Solar cells and solar modules can be interconnected with one another with the switch arrangement described below as an example.

Accordingly, such a switch arrangement, e.g. B. in a solar module, a variety of electrical switches that can electrically connect each individual solar cell with other solar cells or groups of solar cells in series, parallel or in a group circuit. Each solar module consists of a number of solar cells. With dynamic interconnection, subsets are formed from this total amount, which do not have to be arranged geometrically close. These subsets are connected in series, parallel and group depending on the lighting so that the maximum energy can be drawn from the solar module. At the same time, this reduces the energy loss in the bypass diodes and thus lowers the operating temperature of the junction boxes.

In 14th (Source: Source: http://elektrotechnikfachwissen.de/grundlagen/gruppenschaltung.php) a combination of series connection (left) and parallel connection (right), which is called group connection, is shown.

In terms of yield, this concept may not be as performance-optimized as a bypass diode per solar cell, but the possibility of providing additional functions such as AC modules with self-diagnosis, integrated solar module shutdown and de-energized solar modules in the idle state makes the use of electronics (Switch arrangement) attractive again.

A preferred technical solution for the switching elements are semiconductor switches.

These solar cell groups are preferably interconnected in such a way that the flow of current through shaded cells is not hindered and thus little or no current flows through the bypass diode. This reduces the electrical and thus in particular the thermal stress for the system and increases the power yield compared to a rigid electrical connection with bypass diodes.

15th (Source: WO2012163908A2 , 5 ) shows the use of additional diodes as semiconductor switches, through which fewer solar cells than usual are bridged when there is shade.

An embodiment of the proposed electrical interconnection concept provides a completely free interconnection of solar cells / elements in all possible combinations. This would require a large number of switches.

An interconnection concept with more than one power level (power bus line) is presented below.

16 shows two solar modules 27 and 27.2 according to the state of the art. When it comes to voltage sources, electronic devices often have lines with different voltage levels (voltage levels), which are also referred to as buses in the present case. Accordingly, one can also use current sources in circuits set up different power bus lines. State-of-the-art solar modules have only one power bus line, as in FIG 16 shown in which a solar cell string is made up of 20 or 24 solar cells (power sources) in series 26th until 26.6 ( SZS ) is formed. The solar cell string 26th .i, which was identified by the dashed circle in the figure, consists of 20th Solar cells connected in series and a diode. Since the solar cells all have a slightly different output current, even with the same illumination, they become bypass elements D1 to D6 (bypass diodes or Smart Bypass Diodes) are required, which compensate for the output current difference.

A preferred concept is to dynamically interconnect the solar cells so that a solar module has several power outputs. The solar cells are divided into current groups, which, depending on the lighting, have a high current (H-Bus), a medium current (M-Bus) and a low current (L-Bus).

17th shows such a model of a solar module with dynamically interconnected solar cells, which are divided into three power bus lines H, M and L (high, mid, low). The bus lines lead to an inverter 40 with three independent inputs Three separate inverters or one inverter with three separate inputs can preferably be used. Since the efficiency of an inverter is dependent on the input current, a specially optimized inverter is preferably used for each current group H, M and L. The solar module 27 or 27.2 works in this connection as a power source.

That would have a solar panel 27 or 27.2 of this type 6 connection lines. This is not ideal due to the very complex wiring that is prone to errors during installation (tangled cables, errors when plugging together, especially if many switches are required).

In 18th an arrangement is shown in which the number of connection lines is reduced to 2 by interposing electrical energy converters. This can be remedied by connecting the bus lines to a DC / DC converter, the output of which is a voltage source. These converters, each located on the solar module 27 can then easily be connected in series. These DC / DC converters must be able to automatically find the optimal working point of the solar cells. These types of converters are called MPP -Tracker. ( MPPT or Maximum Power Point Tracker) and turn the power source solar module into a voltage source. 18th shows the model of a solar module 27 with dynamic interconnection. The currents are divided over three power bus lines (H1, M1, L1) within the module. The solar element group is in the dashed circle 25th shown on power bus line H1. The solar element groups are set up accordingly on the other power bus lines. Each of these lines has its own Maximum Power Point Tracker ( MPPT -H, MPPT -M, MPPT -L). The output of these trackers, which are connected in series, makes this solar module 27 a voltage source. Even with rigid electrical connections, the use of MPPT on the modules to a higher electricity yield of the solar system compared to the standard circuit in 16 . With a dynamic interconnection as in 18th this yield can be increased even further.

In addition, as in 19th shown several such solar modules 27 and 27.2 according to 18th (dynamically if necessary) interconnected with one another, e.g. B. in series. Since the outputs form voltage sources, a series connection of voltage sources is shown here.

There are preferably three concepts for dynamic interconnection: 1) Conversion of the current sources into voltage sources by electronics (im MPPT implemented implicitly and in 18th shown), 2) Division of the current sources into equal currents, e.g. High, Mid, Low and 3) Combining the current sources in just one current bus according to the in 21st described procedure.

Commercially available modules are supplied already connected and cannot be configured. This means that the interconnection of the SZS are permanently wired in series in the solar module. The possibilities for an interconnection according to the above figures would be better if connection possibilities were freely accessible.

Such modules can still, as in 20th shown can be wired with MPPTs. Modules that are rigidly connected in series can therefore be used when using MPPT can be connected in series.

With dynamic interconnection, the fineness of the subdivision into different power buses can be resolved as required. Every power bus needs one MPPT because the number of cells in a power bus group fluctuates depending on the lighting and the bus voltage is therefore different and variable. Each solar cell can be connected in series to one of the power buses. With complete freedom of choice of connection to power buses, the number of switches or MPPTs required is high.

It is therefore proposed as an additional improvement that, in order to save MPPTs, the power buses and also the solar cells within the solar module are connected in parallel and in group circuits in addition to the series connection.

This means that you only need one MPPT per solar module. In this extreme case, the solar module would become a power source again. If you do without the DC / DC converter at the module output, strings of solar modules with dynamically interconnected solar cells can no longer be connected in parallel because their output voltage fluctuates depending on the lighting. The dynamic interconnection of solar modules within the solar system is therefore preferably carried out analogously to the dynamic cell interconnection.

The number of switches required can be reduced if you limit yourself to suitable connection options for the most common shading geometries. The disadvantage of this is that you lose some performance compared to the optimal solution.

An interconnection concept with only one power level (power bus line) is presented below.

21st describes the procedure and the interconnection geometry for concept 3), ie combining the 3 high and mid low power buses into just one common power bus. In the following it is worked out how many solar cell elements one would like to interconnect as a group. The number of switches increases and so does the control complexity.

The number of switches can be reduced by combining the solar cell elements within a solar module into small groups. These groups can be an n x n cell matrix, in the simplest case a 2 x 2 cell matrix. Other embodiments are conceivable. The interconnection concept is explained using a 3 x 3 cell matrix as an example. A large number of these 3 x 3 cell matrices then form a solar module.

Other designs of square (n x n; n element of natural numbers) or rectangular (n x m; n and m element of natural numbers) cell matrices are conceivable.

The special feature of the 3 x 3 cell matrix is that it can be connected in three vertical, three horizontal or optionally also in three diagonal series connections (strings / strings), which each time have the same number of solar cells and thus the same solar cell string voltage. This facilitates the parallel connection and group connection of these cells within the cell matrix. The solar cells are interconnected in such a way that their geometric arrangement runs parallel to a shadow edge. This introduces a classification that represents a practice-relevant approximation.

The types of interconnection can be made for a 3 x 3 cell matrix as in 16 can be seen for a horizontal course of shading, ie a shadow moving in the vertical direction. The shaded image of the solar cell matrix can be seen on the left, the dynamically selected interconnection for the respective shading situation (a) to (e) on the right.

In an unshaded state (shading situation a), the 3 horizontally arranged strands 26, 26.2 and 26.3 are connected in series, on the one hand not to hinder the flow of current (bypass diodes to keep the bypass diodes as currentless as possible and thus minimize waste heat), and on the other hand to generate the highest possible voltage.

• Schritt 1: Den maximalen Strom der am besten beschienenen Solarzellen ermitteln. Diese kommen in die Reihenschaltung (Linker Teil der Gruppenschaltung gemäß 16)
• Schritt 2: Die restlichen Zellen parallel verschalten, damit die Summe der Teilströme möglichst hoch wird.
• Schritt 3: Sind alle Zellen in der Gruppe „gleichmäßig“ beschienen, aus allen eine Reihenschaltung bilden. Die Zellen gelten als „gleichmäßig“ beschienen, wenn sie eine Stromabweichung von weniger als 30%, bevorzugt von weniger als 20%, insbesondere bevorzugt von weniger als 10% vom Maximalstrom aufweisen.

The following procedure is preferably used for this:

• Step 1: Determine the maximum current of the solar cells with the best light. These come in the series connection (left part of the group connection according to 16 )
• Step 2: Connect the remaining cells in parallel so that the sum of the partial currents is as high as possible.
• Step 3: When all cells in the group are lit “equally”, form a series connection from all of them. The cells are considered to be “uniformly” illuminated if they have a current deviation of less than 30%, preferably less than 20%, particularly preferably less than 10%, from the maximum current.

In the shading situation (b), in which the first strand 26 is partially shaded, it is switched on in parallel to another strand (here 26.2) and forms overall with the strand connected in series 26 a group circuit, so that no more destructive current is forced through the partially shaded strand 26.

In the shading situation (c), in which the second strand 26 is partially shaded, both partially shaded strands 26 and 26.3 are connected in parallel. In the example, there is no longer any dynamic switchover between the switching for the shading situation (b) and the shading situation (c), since the target interconnection according to the shading situation (b) is already in place.

With a freedom of choice for the interconnection, as in the shading situation (b) or (c), assumptions about the future shading can preferably be made in order to carry out the parallel connection of the strings, which would also be beneficial in a subsequent shading situation.

In the case of shading situation (d), when the shadow has covered the entire module and continues to shade unevenly, the same rule applies to the interconnection as described in scenarios (b) and (c).

In the next step, when the shadow has completely and evenly captured the module (shading situation (s)), the strings can be switched back in series or in parallel from the point of view of non-destruction; in 16 a parallel connection is shown. Advantageously, the strings are connected in parallel at low power so that the least possible current flows through the bypass diodes, see 4th and 5 . If bypass flow occurs, it means a great loss of performance.

Can be seen from 21st that the same illuminated (or powerful) solar cells are combined as much as possible. In the example shown, the solar cells can always be combined in the horizontal direction due to the horizontal shadow line. In this case, no switches needed to be provided that could separate 3 horizontal strings of the solar cells and interconnect them differently. The geometric division of the cell matrix is preferably carried out as parallel as possible to a shadow edge. This is the strategy for cell division horizontally, vertically, diagonally, orthogonally. The geometrical divisions just listed are ideal for shading with a shadow edge. However, angular shadows have 2 shadow edges. These are divided up like diagonal shadows to keep the direction selection of the cells simple. This division is not ideal for angular shadows.

This concept can be transferred to all larger units, so matrices of solar modules (instead of individual solar cells) can also be connected in this way.

In the following, proof of the possible increase in energy through the dynamic interconnection concept is shown using simulation calculations.

A simulation model is set up to prove the usefulness of the interconnection method presented. It consists of three groups of three solar cells each, which are connected in series, parallel and group connection. The model simulates an example of horizontal or vertical shading of a 3 x 3 solar cell group.

22nd shows a circuit diagram for the simulation in the special case of series connection. V1-V4, B1 and V6 generate auxiliary variables for the calculation that are required for later finding the maximum performance at any time. They are intended for the numerics of the simulation.

The drawn bypass diodes D4, D10 and D14 above the cell matrix can be replaced by a switch which, through a controller, works as if it were a diode. In integrated form, this is called a cool bypass switch, which can also be set up discreetly.

There are various trade names for the bypass elements, e.g. B. "Cool Bypass Switch", "Smart Bypass Diode" or "Ideal Bypass Diode". What is meant is an NMOS with charge pump and controller in one housing. Alternatively, this can be replaced by a MOS switch.

A sequence of shading with a time offset is introduced into the model, which simulates the shading of the three solar cell groups S1, S2 and S3 following a chronological sequence, as in FIG 18th Shown in a chronological sequence of shading in a fictitious solar system. A section of the diagram 22nd is in 23 shown. The shadow is almost a solar cell wide.

In 24 the output of the unshaded 3 x 3 solar cell group with partial shading is shown parallel to the long module axis in series as a solid line. For the calculation of the power curve, the solar elements were dynamically according to 31 and 32 interconnected. The dotted line shows the solar cell group connected in series with continuous partial shading. The power drops from 176 watts to 149 watts. This corresponds to the state of the art. The power can be increased to 156 watts by group switching at suitable times. This corresponds to an increase in performance of 0.77 watts per cell. The parallel connection of the solar cells does not result in an increase in performance. The unshaded system in series is drawn in solid lines.

If the solar module has been rotated 90 ° with the same shadow geometry, then all three will be SZS shaded at the same time. This situation is in 25th and shows the performance of the 3 x 3 solar cells when the solar module is mounted perpendicular to the shadow edge. The solid line shows the power output with full lighting, the dotted line shows the power output of the module when the cell groups are connected in series, and the dashed line shows the power output when the cell groups are connected in parallel. The comparison of 24 and 25th shows how important the selection of cell groups along a shadow edge is.

When shading occurs, the power drops from 176 watts to 96 watts. By connecting the three cell groups in parallel, the output can be increased to 110 watts. This corresponds to an increase in performance of more than 1.5 watts per cell. The time-dependent optima are in 25th pictured.

An uneven number of groups / strings would be unfavorable if the matrices were connected in an anti-series manner so that zero U, ie no voltage, is present from the module. An anti-series connection is when you connect two voltage sources with the same pole. This results in a two-pole with zero voltage. This connection is useful if you want to achieve that the output voltage is zero volts. This is a useful method to switch a solar system off. But it also works by short-circuiting and interrupting the solar cells, with the short-circuit after DIN VDE AR2100-712 should only take place in the short term.

The number of solar cells per matrix string is preferably the same, because otherwise a current flow would preferentially take place in the shorter string, which would lead to equalizing currents and a loss of power.

In the following, further (in addition to shading by a horizontal shadow line) categorizations of the types of shading that occur in practice are listed. With the restriction to certain categories, switches can be saved.

The electrical wiring concept of the vertically shaded cell matrix, as in 21st corresponds to the wiring concept shown above with horizontal shading in a different orientation. This means that in 21st shown that vertical shading ( 26th ) electrically how horizontal shading can be treated.

Another special case are diagonally shaded cell groups, as in 27 shown. 27 converts diagonal shading into horizontal shading by placing the solar cells in accordance with 28a be divided, which in turn according to the procedure according to 21st are dynamically interconnected and with which an optimization of the interconnection of the solar modules is carried out according to predetermined interconnection types. With diagonal shading, the cells become a 3 x 3 cell matrix as in the 28a and 28b shown, summarized in current or power groups I1 to I3. 28a shows the performance groups for a shading process according to 27 . 28b shows the performance groups for a shading process in an orthogonal direction, from bottom left to top right and thus deals with the diagonal shading rotated by 90 ° 29 and electrically converts it into horizontal shading. These power / power groups are defined as in 21st shown linked in series, in parallel or in groups.

Angularly shaded cell matrices, as in 29 shown, are preferably divided into three groups like diagonally shaded cells in the same geometry. The downside is wasted performance. Ideally, solar cells are grouped according to their lighting. Since the electrical diagonal connection is optimized for diagonal shading, power is wasted with angular shading. However, the gain is still higher than with the rigid interconnection according to the prior art, see 25th . Treated with it 29 the angular shading and translates it into a diagonal Shading according to the 28a or 28b above and thus electrically back into horizontal shading according to 21st .

A large number of the cell matrices are interconnected to form a solar module and the principle of dynamically interconnected solar cells can be applied analogously to these cell matrices. The principle of dynamic interconnection can also be applied to the solar modules as a higher-level cell matrix in a solar system. As already mentioned, the term solar element can encompass both at the solar cell level and at the solar module level.

The division of the solar cells into n x n cell matrices influences the number of solar cells in a solar module. With a division into 3 × 3 = 9 cells, a number of 72 = 8 × 9 cells is preferred. With a division into 2 x 2 cells, a number of 15 x 4 = 60 cells is preferred. 60 and 72 cells are the usual number of cells in standard modules.

In 31 for a 3 x 3 cell matrix a SPICE model is shown, which shows the dynamic interconnection, but not the process concept of 21st includes. On the left side of the block diagram there are 3 bypass diodes (the fourth one is missing), a jumper distribution that realizes the series, parallel and group connection, as well as a pole inverter for anti-parallel connection, separation or alternating current generation.

The solar element can be completely disconnected (i.e. switched off) by the polarity reverser, creating an intrinsically safe solar module that only provides energy after a prior release signal. Solar systems can thus be completely de-energized. This, too, is new compared to the state of the art, which accomplishes this interconnection using additional electronics.

Furthermore, solar elements can be connected together in such a way that they remain electrically conductive, but do not provide any output voltage because they compensate each other (anti-serial connection).

The pole inverter can also be used to generate alternating current. An alternating current with a frequency of more than 100 kHz significantly reduces the risk of muscle cramps and cardiac arrest / fibrillation.

In the middle of 31 is the geometric selection of the solar cells from the example 3 x 3 cell matrix for the division into horizontal, vertical, diagonal and 90 ° -turned diagonal (orthogonal).

29 is an incomplete section of the required intermediate circuits or jumper distributors within the 3 x 3 cell group 31 and contains a small part of the switches.

Due to the optional communication (release signal) and the method for performance optimization, the overall circuit preferably has a microprocessor which can interconnect the 8 3x3 cell matrices horizontally, vertically, diagonally, rotated by 90 °, diagonally and also at an angle. This is then referred to as a smart module. As a standard, the solar system can be rigidly interconnected using smart modules. A dynamic interconnection of the solar modules is preferably provided, which can be interconnected horizontally, vertically, diagonally, diagonally 90 °, angularly or in block form as required.

• Solarzellen mit gleicher Beleuchtung werden bevorzugt in Gruppen zusammengefasst. Die Gruppen werden bevorzugt parallel verschaltet. Wenn nicht gleich das ganze Modul verschattet ist, dann sind in dieser Betriebsart die Bypasselemente nicht in Betrieb. Optional kann die Ausgangsspannung dynamisch verschalteter Solarmodule durch einen integrierten DC/DC-Wandler auf normales Niveau angehoben werden.

Further variants of the described interconnection variants result in further advantages:

• Solar cells with the same lighting are preferably grouped together. The groups are preferably connected in parallel. If the entire module is not immediately shaded, the bypass elements are not in operation in this operating mode. Optionally, the output voltage of dynamically connected solar modules can be increased to a normal level using an integrated DC / DC converter.

Due to the dynamic interconnection, the polarity of the solar module can be reversed in steps. This means that the solar module can supply alternating current by itself. This alternating current can be used to create a DC / DC converter or with a few additional components MPP Form tracker. Alternatively, the solar cells can be connected in such a way that no voltage is released from the solar module to the outside, which means that it is then in a non-dangerous idle state. Operation is initiated by external communication. An intrinsically safe solar module with integrated emergency shutdown can thus be implemented.

An "AC module" operating mode is made possible by switching the switches accordingly and thereby generating an alternating voltage / current. The frequency does not necessarily have to be 50 Hz. Raising the frequency to preferably 300 kHz has the advantage that transformers for voltage separation or transducers can be smaller and therefore cheaper and that if they come into contact with the system voltage in the event of an accident, the currents flow through the skin and not through the heart (skin effect) . Muscle spasms would then not take place. This makes the system voltage less dangerous for people than with conventional systems. In addition, the alternating current facilitates automatic extinction of arcs in the event of a fault due to its current zero crossings.

The operating modes listed above are preferably controlled by a microcontroller or microprocessor. Therefore a communication network of the solar modules with further advantages is conceivable with little additional effort. If, for example, an external fire occurs, this information can be reported to all modules through temperature monitoring. These can then all switch off automatically before the fire has hit the entire system.

The status of all modules can be reported to a control center. This can e.g. B. Operating status, current, voltage, temperature, hardware check and optionally include other parameters.

Each solar module can report in the form of a homepage. This means that a SMART module can preferably be implemented in the Internet of Things, which is integrated in the SMART Home.

The microprocessor preferably takes on the task of arc detection and module shutdown.

The microprocessor preferably takes on the function of theft protection and a location report.

The microprocessor preferentially monitors the hardware so that it protects itself. This can include exceeding a maximum operating temperature as well as lightning protection measures.

The firmware of the processor is preferably kept up to date with updates.

An error status is preferably communicated to the outside via a corresponding electronic message or alternatively or additionally also optically or acoustically, so that the search for the defective module is shortened in large systems.

In this way, an optimized arrangement of solar elements with dynamic interconnection during operation of the solar elements depending on their current performance characteristics and a method for controlling such an arrangement of solar elements has been provided, which is suitable for optimizing the interconnection of the solar modules according to predetermined types of interconnection.

31 and 32 shows an arrangement of the solar elements according to a preferred embodiment with a crossbar distributor. In this arrangement, the solar elements are assigned to different routing levels, which enables the solar elements to be connected in series, groups and in parallel. 33 corresponds in essential parts 31 .

34 shows an arrangement of the solar elements according to a preferred embodiment with a simplified group circuit compared to the circuit according to FIG 31 . The connection types, series connection, group connection G1 and G3 as well as parallel connections are hereby in accordance with possible. In the distribution board ( 33 bottom left) the geometric center of the 3x3 matrix is assigned to the distribution boxes ZS2 + and ZS2-. The circuit shown allows the number of switches required in comparison to the crossbar distributor according to 31 be limited. The circuit shown has, for example, 27 switches.

35 shows in a schematic representation different arrangements of the solar elements according to preferred embodiments. According to the arrangement on the left, the solar elements are interconnected in such a way that they are present in an arrangement of three vertically running strings. According to the second arrangement from the left, the solar elements are interconnected in such a way that they are present in an arrangement of three horizontally running strings. According to the two right-hand arrangements, the solar elements are interconnected in such a way that they result in diagonally running strings, the strings in the third arrangement of FIG on the left run diagonally from top left to bottom right and in the right arrangement diagonally from bottom left to top right. For example, a dynamic interconnection according to a preferred embodiment can take place in such a way that between the in 21st arrangements shown is changed. Optionally, further interconnections or arrangements can be provided according to which solar cell strings or the solar elements can be interconnected in order to optimize the efficiency of the solar cell arrangement when there is shade.

36 shows a schematic representation of a solar cell arrangement according to a preferred embodiment, which is referred to as a pole-turning circuit, in a schematic illustration at the bottom left. The pole changer is arranged and / or designed in such a way that the geometric center of the 3x3 matrix can be switched back to the routing levels ZS2 + and ZS2- by means of the pole changer. The geometric center of the 3x3 matrix is placed on a pole changer according to the circuit shown at the bottom left. This circuit enables series, group and parallel circuits to be implemented. The in 36 The polarity reverser shown at the bottom right can generate alternating voltage at the output of the solar module.

37 shows a circuit of cell strings or strands 26a , 26b , 26c according to a preferred embodiment. Here are the strands 26b and 26c connected in series in such a way that they form an arm of a parallel circuit. The strand is in the other arm of the parallel connection 26c and a diode D4 connected in series. Such a circuit is preferably implemented with a pole-changing circuit and / or a diode matrix circuit. This circuit offers the advantage that diodes can be connected in series with one or more strings and in this way strings of different lengths or with a different number of solar cells can be connected in parallel without creating disadvantageous equalizing currents. Furthermore, this circuit offers the advantage that several arms each with a different number of strings connected in series 26th can be connected in parallel and yet no equalizing currents are caused between the arms of the parallel connection. Instead of strands 26th Solar cells and / or groups can also be connected in this way in the same way.

A comparable circuit is also possible in which the arms of the parallel circuit run horizontally and the diode accordingly in series with the strand 26c parallel to the two strands connected in series 26a and 26b is switched.

38 shows a schematic representation of a circuit according to a preferred embodiment, which a diode matrix circuit according to 40 and a pole reverser circuit according to 36 combined. Due to the diode matrix circuit, the circuit is set up to independently interconnect the solar elements by means of diodes in an arrangement that is adapted to the shading conditions. In other words, one can look to the selection of solar cell groups along a shadow edge 32 dispense. In this way, the diode matrix circuit makes it possible to implement a passive, dynamic interconnection of the solar cells or groups or strings. The diodes are controlled by the voltages generated by the solar cells. Only if the entire 3x3 matrix or all solar cells were completely shaded would the diode matrix lead to a disadvantageous connection, since in this case the diode matrix would connect the three strings in series, which would create a large electrical resistance for the current flow and the current would therefore overflow Diodes is diverted within the diode matrix. In the case of full shading, provision is therefore made to switch the three strings in parallel by means of the polarity reverser in order to enable a sufficient flow of current even with full shading. For this purpose, the circuit is preferably set up to reverse the polarity of the middle strand in order in this way to connect the three strings in parallel that would otherwise be connected in series, ie without a pole inverter and only with the diode matrix circuit. In this way, with a combination of the diode matrix circuit and a pole-reversing circuit, a circuit can be implemented in which the solar cells can be dynamically interconnected with great flexibility and which ensures a suitable interconnection or arrangement of the solar cells or solar elements in all shading conditions.

In the 38 The switches S6 and S7 shown are not absolutely necessary and can be omitted according to another preferred embodiment.

The diode matrix circuit delivers the best yield with partial shade and also offers the advantage that the number of required components can be kept low. Only when fully shaded does a division of the solar elements into current groups by means of a pole reverser lead to a better result. With a combination of the two types of circuit according to 38 can therefore yield at all Shading conditions can be optimized and yet the number of components required, in particular the need for switching elements such as MOSFETs and diodes, are reduced. Table 1 lighting StdT Combination circuit (Fig. 38) Diode matrix circuit ( 40 ) Current groups or pole reversing circuit (Fig., 36) Yield unshaded 9A 100% 100% 100% 100% Yield fully shaded 3A 67% 79% 66% 77% Horizontal shading yield 3A 67% 89% 89% 89% Yield vertically shaded 3A 89% 90% 89% 89% Yield diagonal shading et 3A 78% or 66% 89% 89% 79% or 89% Yield cross-shaded 3A 78% or 66% 89% 89% 89% Number of diodes 3 Max. 15 15th 6th Number of switches 0 Max. 6 0 22nd

Table 1 shows an overview of the yields of the various circuits with different shading conditions, as well as the required number of diodes and switches.

36 shows a schematic representation of a pole changer according to a preferred embodiment. While for one related to 36 described pole reverser circuit and one with reference to 38 described combination of diode matrix circuit 40 and pole reverser circuit 36 a pole inverter is integrated in the mxn matrix or 3 x 3 matrix, another pole inverter can be formed in such circuits and / or in other circuits, which is arranged at the output of the mxn matrix or 3 x 3 matrix. In particular, several mxn matrices can be formed in the solar cell arrangement, each via a pole inverter 39 at the output of the mxn matrix. Solar cells or solar elements or matrices can then, if necessary, be bridged via these polarity reversers at the outputs, for example if they have a defect. In particular, defective 3 x 3 matrices can be bridged by means of the pole reverser if they contain defective solar cells or are completely defective. This can be achieved, for example, by the fact that the left half bridge of the in 39 The pole changer shown is switched to high resistance and both switches for the right half bridge SW switched to continuity. The function of the half bridges can be exchanged for this task.

32 shows an arrangement according to a preferred embodiment, which according to the division of solar cell groups along a shadow edge and thus the division of the solar cells into the three current groups high, mid and low 21st shows. With such a circuit, a string and / or individual solar cells within a 3 x 3 matrix can be isolated by using the switches SW switched to interruption.

Solar cell arrangements with 60 cells, as which standard modules are often present, typically have three strings with a cell division of 20 solar cells in series, which can be bridged with a diode, such as a bypass diode. When using 3 x 3 matrices, it is advantageous if the number of solar cells in the vertical direction is a multiple of the number three. This is the case with 72 cells and with 60 cells two rows in the top 3 x 3 matrices are unfilled.

Either the partially filled 3 x 3 matrices or a row of solar cells are omitted and there is space for a strip of electronics in the solar module (this corresponds to a 54-cell solar module) or the gaps in the 3 x 3 matrix are bridged with short circuits (this corresponds to a standard 60 cell module). This results in a simplified switch concept, because, for example, the diagonal connection and the perpendicular cross connection are not useful and bridged switches can be omitted.

Preferred cell divisions are shown in schematic representations in 35 and 26 to 29 are shown by way of example. For some applications, such as for solar facades, a low system voltage of the solar cell arrangement, for example 120 V DC, is preferred in order to avoid a risk from the solar cell arrangement, such as the risk of electric shock due to high electrical voltage, in the event of an accident and / or malfunction , to limit. A 3 × 3 cell group is also preferably selected as a matrix for solar cell arrangements. The division of the cell group within the 3 x 3 matrix is optional. In the following, possible divisions of the solar cells of 72-cell standard modules are explained by way of example, by means of which a 3 x 3 matrix can be implemented.

41 to 47 show a solar cell arrangement according to a preferred embodiment, which comprises 3 SMART 72-cell solar modules which are arranged horizontally next to one another.

40 Figure 3 shows a diode matrix circuit in accordance with a preferred embodiment. 40 shows a variant of the circuit optimized for 72 cell modules 15th which is optimized for 60-cell modules.

41 and 42 show a further solar cell arrangement according to a preferred embodiment, which comprises 3 SMART 72-cell solar modules. One solar cell is combined into a group. Accordingly, N = 1, so that each group comprises one solar cell.

The 43 and 45 show a further solar cell arrangement according to a preferred embodiment, which comprises 3 SMART 72-cell solar modules. Two solar cells arranged vertically one above the other are combined to form a group. Accordingly, N = 2, so that each group comprises two solar cells.

44 and 46 show a further solar cell arrangement according to a preferred embodiment, which comprises 3 SMART 72-cell solar modules. Four solar cells arranged vertically one above the other are combined to form a group. Accordingly, N = 4, so that each group comprises four solar cells.

47 shows a further solar cell arrangement according to a preferred embodiment, which comprises 3 SMART 72-cell solar modules. Eight solar cells are combined into a group, namely four vertically one above the other and two horizontally next to one another. Accordingly, N = 8, so that each group comprises eight solar cells. Such a number of solar cells offers the advantage that exactly a 3 x 3 matrix can be realized with a solar module with 72 solar cells. With three such modules, three 3 x 3 matrices of groups with eight solar cells each can be realized.

Depending on the choice of the parameter N, a different number of switches, such as MOSFETs and / or diodes, is necessary within the SMART solar modules or the solar cell arrangement. The electrical resistance of the switches can reduce the system's yield. The calculations take into account an electrical resistance of 9 milliohms for the supply lines (3 modules with 2 pieces each 1 meter 4mm ² solar cables with 0.5 milliohm each for the solar connector pairs). On the one hand, the finest possible cell division (N as small as possible) is desirable in order to be able to implement dynamic interconnection that is as flexible as possible. On the other hand, the lowest possible number of switches (N as large as possible) is desirable in order to minimize manufacturing costs and electrical resistance. 1 milliohm was assumed for the resistance of the switches.

If N = 1 is selected (a solar cell is an element or a group of the 3x3 matrix), a large number of switches is required. This means that in unshaded operation (for example 6 a.m. to 11 a.m. and 1 p.m. to 6 p.m.), a reduction in the yield of the solar generator due to the many switches must be accepted. The increase in output during the shading almost compensates for this loss of yield. However, with such a fine division of the groups, the interconnectability cannot overcompensate for the losses, so that with regard to the yield, a choice of N = 1 is not worthwhile, but divisions with several solar cells per group can be more advantageous.

For the yield or the efficiency of a solar cell arrangement, it can therefore be advantageous to reduce the switching losses by using a large number of switches. This can be done, for example, as described above, by combining several solar cells into a group. Alternatively or in addition, a different division of the matrix can also be advantageous.

36 shows a preferred solar cell arrangement in a schematic representation, which is based on a diode matrix circuit and a pole reverser circuit. the solar cell arrangement is characterized by the fact that it has only eight switches. The voltage controlled switches are as diodes D1 to D4. These can preferably be designed as diodes, or particularly preferably designed as transistor switches (MOSFETs). Alternatively, the switches can be designed as cool bypass switches or as smart bypass diodes.

The solar cell arrangement according to 37 offers the advantage that the parallel connection of strings of different lengths, ie strings with a different number of solar cells, is made possible, for example with reference to FIG 34 and only eight switches are required.

• • Vereinfachte Gruppenschaltung gemäß 34 oder als
• • Polwenderschaltung gemäß 36 oder als
• • Diodenmatrixschaltung mit Polwender gemäß 38 oder als
• • Polwenderschaltung mit vereinfachter Diodenmatrix gemäß 48

A crossbar distribution circuit according to 31 and 32 can thus be designed according to preferred embodiments in such a way that switching elements are saved. In particular, the following circuits can be implemented:

• • Simplified group switching according to 34 or as
• • Pole reverser circuit according to 36 or as
• • Diode matrix circuit with pole inverter in accordance with 38 or as
• • Pole reverser circuit with simplified diode matrix in accordance with 48

The geometric division of solar cell groups along a shadow edge is preferably based on the circuit in all variants 32 which can also isolate individual solar cells or groups of solar cells from the flow of current.

In the diode matrix circuit with pole reverser and in the pole reverser circuit with a simplified diode matrix, the geometric selection of solar cells can be made 32 Optionally omitted along a shadow border in order to save switches.

List of reference symbols

1

Arrangement of several solar elements

10

Counter ( SW , Sx )

20th

Solar element

22nd

Solar cell

25th

group

26, 26a, 26b, 26c

strand

27

Solar module

27a

Smart module

27b

conventional solar module

30th

Control unit

40

Inverter

42

Reverser

44

Reversing control unit

46

Rectifier

100

building

SC, Sx

Solar cell

D, D1, Dx

(Bypass) diode

SZS, PC _x

Solar cell string

I.

electricity

R _L

Load resistance

MPP

Maximum power point

P (MPP)

Power curve for determining the power in MPP

U (MPP)

Stress curve for determining the stress in MPP

SW, Sx

Switch

MPPT

Maximum Power Point Tracker

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102011055754 A1 [0004]
• WO 2012163908 A2 [0004, 0137]
• JP 2014068509 A [0006]
• US 2015155818 A1 [0006]
• EP 1970965 A1 [0006]
• US 2010157632 A1 [0033]
• US 7256566 B2 [0056]
• EP 1045455 B1 [0061]
• US 6225793 B1 [0061]
• US 2014/0375145 A1 [0081, 0082]
• WO 2012163908 [0085]
• US 6225793 [0085]

Non-patent literature cited

• DIN VDE AR2100-712 [0177]

Claims (12)

Method for optimizing an interconnection of a solar module (27) which has several solar elements (20), the method comprising the steps: - Provision of a plurality of predetermined types of interconnection according to which the solar elements (20) can each be interconnected within the solar cell module (27); - sequential connection of the solar elements (20) according to the predetermined connection types and determining an efficiency parameter of the solar module (27) for each connection according to one of the predetermined connection types; - Determining an optimal type of interconnection of the predetermined types of interconnection in which the solar module (27) has the best efficiency parameter; - Interconnection of the solar module (27) according to the optimal interconnection type. Procedure according to Claim 1 , wherein the predetermined types of interconnection differ at least in that the solar elements (20) of the respective solar module (27) are interconnected in differently arranged solar cell strings and / or solar cell groups. Procedure according to Claim 1 or 2 , the predetermined types of interconnection being predetermined as a function of the various shading situations to be expected for the respective solar module (27). Method according to one of the preceding claims, wherein the provision of the predetermined connection types comprises the provision of at least 2, preferably at least 3, more preferably at least 4, even more preferably at least 5, much more preferably at least 6, most preferably at least 7 different predetermined connection types ; and / or wherein the provision of the predetermined types of interconnection comprises the provision of no more than 100, preferably no more than 50, more preferably no more than 30, much more preferably no more than 20, most preferably no more than 10 different predetermined interconnection types . Method for optimizing a solar cell arrangement (1) with a plurality of solar modules (27) and an inverter (40), wherein the solar cell modules (27) are connected in series and connected to an input of the inverter (40). - Setting the solar cell arrangement (1) to an operating point (MPP) with an optimized operating current by means of the inverter (40); - Optimizing the interconnection of the solar modules (27) according to one of the preceding claims. Procedure according to Claim 5 wherein the wiring of the solar modules (27) is optimized in such a way that there is no temporal overlap with the setting of the solar cell arrangement (1) by means of the inverter (40). Procedure according to Claim 5 or 6th wherein the optimization of the interconnection for each of the solar modules (27) is carried out independently by the respective solar module (27). Procedure according to Claim 7 wherein the optimization of the interconnection of the solar modules (27) for at least some, preferably for all, of the solar modules (27) takes place at least partially at the same time. Method according to one of the Claims 5 to 8th , the optimization of the interconnection of the solar modules (27) being triggered by means of a trigger signal, the inverter (40) preferably providing the trigger signal. Procedure according to Claim 9 , wherein the setting of the solar cell arrangement (1) to an operating point with an optimized operating current comprises varying the operating current by means of the inverter (40) and wherein the trigger signal is provided on the basis of the varying operating current. Solar module (27), the solar module (27) being set up to carry out the following steps: providing a plurality of predetermined types of interconnection, according to which the solar elements (20) can each be interconnected within the solar module (27); - sequential connection of the solar elements (20) according to the predetermined connection types and determining an efficiency parameter of the solar module (27) for each connection according to one of the predetermined connection types; - Determining an optimal type of interconnection of the predetermined types of interconnection in which the solar module has the best efficiency parameter; - Interconnection of the solar module (27) according to the optimal interconnection type. Solar cell arrangement (1), comprising several solar modules (27) and an inverter (40), the solar modules (27) being connected in series and connected to an input of the inverter (20) and the solar cell arrangement (1) being set up to do the following Steps to perform: - Setting the solar cell arrangement (1) to an operating point with an optimized operating current by means of the inverter (40); - Provision of a plurality of predetermined types of interconnection for each solar module (27), according to which the solar elements (20) can each be interconnected within the respective solar cell module (27); - sequential connection of the solar elements (20) according to the respective predetermined connection types and determining an efficiency parameter of the respective solar module (27) for each connection according to one of the predetermined connection types; - Determination of an optimal connection type of the predetermined connection types, in which the respective solar module (27) has the best efficiency parameter; - Interconnection of the solar modules (27) according to the optimal type of interconnection in each case.

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