CN106253330B

CN106253330B - Photovoltaic power optimization system

Info

Publication number: CN106253330B
Application number: CN201610645214.3A
Authority: CN
Inventors: 张永
Original assignee: FONRICH NEW ENERGY TECHNOLOGY Ltd SHANGHAI
Current assignee: FONRICH NEW ENERGY TECHNOLOGY Ltd SHANGHAI
Priority date: 2016-08-09
Filing date: 2016-08-09
Publication date: 2022-05-31
Anticipated expiration: 2036-08-09
Also published as: CN106253330A

Abstract

The invention mainly relates to a photovoltaic power optimization system which is provided with a plurality of photovoltaic modules connected in series, wherein each photovoltaic module is provided with a carrier sending module and is used for forming a communication carrier on a transmission line connected with the photovoltaic modules in series; each photovoltaic module is provided with a carrier detection module and is used for extracting communication carriers on a transmission line; wherein at least a portion of the photovoltaic modules are configured with a wireless communication module: enabling at least one part of the photovoltaic modules to receive or send first data embodied in a wireless communication form through the wireless communication module; and/or the photovoltaic component receives second data embodied in the form of a communication carrier on the transmission line by means of the configured carrier detection module.

Description

Photovoltaic power optimization system

Technical Field

The invention mainly relates to a solar power generation electric device, in particular to a scheme that a multi-stage voltage conversion circuit is used in each photovoltaic module, so that any one stage of voltage conversion circuit can independently execute independent maximum power point tracking calculation on a corresponding battery string, and the stability of the output power of the whole solar power generation system is ensured.

Background

With the limitation of traditional energy sources such as petroleum, coal, natural gas and the like and the increasingly serious negative environmental problems caused by the traditional energy sources, particularly under the large conditions of economic, political and social environments which change continuously around the world, the search for inexhaustible and repeated renewable energy sources to replace traditional chemical energy sources with limited resources and environmental pollution becomes an important proposition which needs to be solved urgently around the world. Nowadays, renewable, environment-friendly and sustainable new energy sources are increasingly widely applied, and the technology development based on new technologies and new materials enables the renewable energy sources to be developed and utilized in a modernized manner, such as solar energy, geothermal energy, wind energy, ocean energy, biomass energy, nuclear fusion energy and the like. Because the new energy of the solar photovoltaic has the advantages of cleanness, safety, reliability, low operation cost, simple daily maintenance, availability at any place and the like, the photovoltaic power generation becomes a novel industry which is generally concerned and intensively developed in all countries in the world, the photovoltaic industry is rapidly developed in the world, and the photovoltaic power generation plays an indispensable role in solving the power utilization problem in remote areas.

The output characteristics of the photovoltaic cell are greatly changed under the influence of the external temperature and the illumination radiation intensity, so that the photovoltaic cell can always output the maximum power, and the solar energy is more effectively utilized as the basic requirement of a photovoltaic power generation system. To output the desired maximum power from the solar panel, it is most important to find the maximum power point MPPT at which the panel output voltage and current are maintained. The change of the maximum power point is usually related to the irradiation intensity and the ambient temperature, so the problem to be solved is that when the environment of the solar panel changes, the parameters which need to be dynamically tracked change to eliminate the external environmental factors and ensure that the solar panel works at the maximum power point. The problem of shadow masking of the photovoltaic module causes a degradation of the photovoltaic module, the normal degradation range being about 5% in the first year, not more than 0.8% in the following years, and about 20% in the 25 years. And due to the factors of inconsistency of outgoing products and inconsistency of attenuation, the generated energy of the solar panel is probably lost by 3-5%. The attenuation of the component is caused by many reasons, mainly including production and manufacturing factors, environmental factors and the like, wherein the production and manufacturing factors mainly include: production process, self-attenuation and aging degree; the environmental factors mainly include: cloud cover, fallen leaves, temperature, installation inclination angle and orientation, etc.

In current Photovoltaic power optimization approaches, optimization is almost always performed at the Photovoltaic module level, which means that each individual cell string is not optimized individually, and actually each Photovoltaic module usually includes a plurality of cell strings (Photovoltaic cell strings) formed by Photovoltaic cells connected in series. When the same string of battery plates cannot normally generate electricity due to poor product consistency or shadow shielding and other factors, the efficiency loss of the whole string of photovoltaic cells is serious, and when inverters, particularly centralized inverters, access a plurality of battery plate arrays, the battery plates of all strings can not operate at the maximum power point of the inverters, which are losses of electric energy and generated energy. Therefore, the power optimizer described later in this application mainly solves or alleviates these problems, and implements power optimization at a battery string level to carry an active power optimizer for each photovoltaic battery string, and introduces maximum power point tracking to ensure stability of output power of the solar system and maximum optimization of power.

Disclosure of Invention

In one embodiment, the present invention provides a photovoltaic power optimization system having a plurality of photovoltaic modules connected in series, wherein: the photovoltaic module is provided with a carrier sending module and/or a wireless communication module to realize data sending, and the carrier sending module is used for forming a communication carrier on a transmission line which is connected with the photovoltaic module in series; the photovoltaic module is provided with a carrier detection module and/or a wireless communication module to realize data receiving, and the carrier detection module is at least used for extracting communication carriers on the transmission line; at least one part of the photovoltaic modules receive or send first data embodied in a wireless communication form through a configured wireless communication module; and/or the photovoltaic component receives second data embodied in the form of a communication carrier on the transmission line by a configured carrier detection module.

In the photovoltaic power optimization system, the carrier transmitting module at least includes a first switch and a capacitor connected in series;

and at the stage that the carrier sending module sends the communication carrier, the first switch is controlled by the processor configured by the photovoltaic module to switch between a switch-off state and a switch-on state, so that a current carrying a data carrier is formed on a transmission line.

In the photovoltaic power optimization system, the carrier sending module includes a first switch, a capacitor and a first resistor, which are connected in series, and the carrier sending module further includes a second resistor connected in parallel to two ends of the capacitor.

In the photovoltaic power optimization system, the carrier sensing module includes a current detection unit (sometimes also referred to as a current sensor) for monitoring current information on the transmission line and a filter for extracting a preset communication carrier signal having a specified frequency range from the current information.

In the above photovoltaic power optimization system, a first type of module among the photovoltaic modules is configured with a wireless communication module, and a second type of module among the photovoltaic modules is not configured with a wireless communication module; when the processor configured by the first type of component receives first data transmitted by the wireless communication module, the processor forms second data representing the first data on a transmission line by controlling the carrier transmitting module configured by the first type of component; and the carrier sensing module configured by the second type of component extracts the second data and transmits the second data to the processor of the second type of component.

In the above photovoltaic power optimization system, the first and second types of components in the photovoltaic component are both configured with wireless communication modules, and in the case that the wireless communication modules of the second type of component are shielded (for example, the wireless communication modules of some components are shielded or semi-shielded by walls or other physical structures that are easy to shield wireless signals), the wireless communication modules of the first type of component and the second type of component are configured with wireless communication modules: when the processor configured by the first type of component receives first data transmitted by the wireless communication module, the processor forms second data representing the first data on a transmission line by controlling the carrier transmitting module configured by the first type of component; and the carrier sensing module configured by the second type of component extracts the second data and transmits the second data to the processor of the second type of component.

The photovoltaic power optimization system further comprises an inverter for converting direct current output by the photovoltaic modules in series into alternating current, wherein the first data is transmitted by a wireless communication device integrated with the inverter.

The photovoltaic power optimization system, wherein the first data is sent by a wireless communication device, and the wireless communication device is an independent terminal device used with the photovoltaic module.

In the photovoltaic power optimization system, each photovoltaic module comprises a first-stage photovoltaic cell string or a multi-stage photovoltaic cell string, each photovoltaic module is also provided with a power optimizer, each power optimizer comprises a multi-stage voltage conversion circuit, and each stage of voltage conversion circuit performs voltage boosting or voltage reduction conversion on the voltage generated by the corresponding first-stage photovoltaic cell string to output;

and the output voltages of the power optimizers respectively configured to the photovoltaic modules connected in series are superposed together to be used as the total output voltage of the photovoltaic modules.

In each power optimizer of the photovoltaic power optimization system, any one of the voltage conversion circuits performs voltage conversion on the voltage generated by the corresponding first-stage photovoltaic cell string and outputs the voltage on one output capacitor, the output capacitors of the voltage conversion circuits of each stage in each power optimizer are connected in series, and one carrier sending module configured for each photovoltaic module is connected in parallel with the output capacitors connected in series.

The photovoltaic power optimization system comprises, in each power optimizer: any one of the voltage conversion circuits performs voltage boosting or voltage reducing conversion on the voltage generated by the corresponding one-stage photovoltaic cell string and outputs the voltage on one output capacitor, and the output capacitors of the multi-stage voltage conversion circuits in each power optimizer are connected in series, so that the voltage superposed on the output capacitors in series provides the output voltage of each power optimizer.

According to the photovoltaic power optimization system, the voltage conversion circuits are Buck-type Buck circuits, each voltage conversion circuit independently performs maximum power point tracking calculation on one photovoltaic cell string, and therefore each level of voltage conversion circuit outputs the maximum power of the corresponding level of photovoltaic cell string.

The above photovoltaic power optimization system further includes, in a power optimizer configured for each photovoltaic module: a second switch provided in any one or more stages of the voltage converting circuit thereof, in the voltage converting circuit with the second switch: the output capacitor and the second switch are connected in series between a group of output ends of the voltage conversion circuit.

In the photovoltaic power optimization system, at the stage that the carrier sending module configured for each photovoltaic module sends the communication carrier: the second switch is controlled by a processor configured by the photovoltaic module to be switched into a turn-off state so as to break a serial branch circuit formed by respective output capacitors of each level of voltage conversion circuits in a power optimizer matched with the photovoltaic module; and the second switch is controlled by the processor to be switched into a switch-on state until the phase that the carrier sending module sends the communication carrier is finished.

In the photovoltaic power optimization system, each photovoltaic module is also provided with a power module for providing stable voltage, the power module respectively converts the voltage generated by each level of photovoltaic cell string of the photovoltaic module into stable voltage to be output, and the voltage generated by each level of photovoltaic cell string is respectively transmitted to the power module through a diode; and/or the power supply module converts the output voltage of a power optimizer which is configured corresponding to the photovoltaic module into stable voltage and outputs the stable voltage.

In the photovoltaic power optimization system, at the stage that the carrier sending module configured for each photovoltaic module sends the communication carrier: and the power supply module for limiting the configuration of each photovoltaic module only collects and converts the voltage generated by each stage of photovoltaic cell string of the photovoltaic module into stable voltage for output, and does not collect the output voltage of the power optimizer.

The photovoltaic power optimization system further comprises an inverter for converting direct current output by the photovoltaic modules in series connection into alternating current, wherein the inverter comprises a carrier detection module; and when the processor of at least one photovoltaic component configuration receives the first data transmitted by the wireless communication module of the photovoltaic component configuration, the processor of the photovoltaic component configuration forms second data representing the first data on the transmission line by controlling the carrier sending module of the photovoltaic component configuration.

And the carrier detection module configured by the inverter extracts the second data and transmits the second data to the processor of the inverter.

The photovoltaic power optimization system also comprises a data acquisition device with a carrier sensing module, wherein the data acquisition device is used for acquiring the specified parameters of the photovoltaic cell; the processor of the photovoltaic component configuration forms communication carrier data representing the designated parameters on a transmission line by controlling the carrier sending module of the photovoltaic component configuration; the data acquisition equipment extracts the communication carrier representing the designated parameter on the transmission line by using a carrier detection module, so as to acquire the designated parameter information of the photovoltaic cell.

In one embodiment, the present invention provides a data communication method for a photovoltaic power optimization system having a plurality of photovoltaic modules connected in series: in the photovoltaic power optimization system: the photovoltaic module is provided with a carrier sending module and/or a wireless communication module to realize data sending, and the carrier sending module is used for forming a communication carrier on a transmission line which is connected with the photovoltaic module in series; the photovoltaic module is provided with a carrier detection module and/or a wireless communication module to realize data receiving, and the carrier detection module is at least used for extracting communication carriers on the transmission line; the data communication method comprises the following steps: sending data to the wireless communication modules configured for all the photovoltaic modules respectively by utilizing wireless communication equipment, and directly communicating with all the photovoltaic modules by utilizing the wireless communication equipment; or the wireless communication device is used for sending first data to the wireless communication module of the first part of photovoltaic module configuration, and when the processor of the first part of photovoltaic module configuration receives the first data transmitted by the wireless communication module, the processor of the first part of photovoltaic module configuration forms second data representing data information of the first data on a transmission line by controlling the carrier sending module of the first part of photovoltaic module configuration; and the carrier sensing module configured by the photovoltaic module of the second part extracts the second data on the transmission line, so that the wireless communication device directly communicates with the photovoltaic module of the first part, and the wireless communication device indirectly communicates with the photovoltaic module of the second part in a data relay mode (namely, the relay from the first data to the second data).

In the method, the carrier transmitting module at least includes a first switch and a capacitor connected in series; and at the stage that the carrier sending module sends the communication carrier, the first switch is controlled by the processor configured by the photovoltaic module to switch between an off state and an on state so as to form carrier current carrying data on the transmission line.

In the method, the carrier sensing module includes a current sensor for monitoring current information on the transmission line and a filter for extracting a predetermined communication carrier signal having a specified frequency range from the current information.

In the method, the carrier transmitter module includes a first switch, a capacitor and a first resistor connected in series, and the carrier transmitter module further includes a second resistor connected in parallel across the capacitor.

In the above method, the photovoltaic power optimization system further comprises an inverter for converting dc power output by the series-connected multiple photovoltaic modules into ac power, wherein the wireless communication device is integrated into the inverter.

In the method, the wireless communication device is an independent terminal device matched with the photovoltaic module for use.

In the method, each photovoltaic module comprises a plurality of stages of photovoltaic cell strings, each photovoltaic module is further provided with a power optimizer, each power optimizer comprises a plurality of stages of voltage conversion circuits, and each stage of voltage conversion circuit performs voltage boosting or voltage reducing conversion on the voltage generated by the corresponding stage of photovoltaic cell string to output; the output voltages of the power optimizers respectively configured to the photovoltaic modules connected in series are added together to serve as the total output voltage of the photovoltaic modules.

In each power optimizer, any one of the voltage conversion circuits performs voltage conversion on the voltage generated by the corresponding first-stage photovoltaic cell string and outputs the voltage on one output capacitor, the output capacitors of the voltage conversion circuits of each stage in each power optimizer are connected in series, and one carrier sending module configured for each photovoltaic module is connected in parallel with the output capacitors connected in series.

The method described above, in each power optimizer: any one of the voltage conversion circuits performs voltage boosting or voltage reducing conversion on the voltage generated by the corresponding one-stage photovoltaic cell string and outputs the voltage on one output capacitor, and the output capacitors of the multi-stage voltage conversion circuits in each power optimizer are connected in series, so that the voltage superposed on the output capacitors in series provides the output voltage of each power optimizer.

In the method, the voltage conversion circuits are Buck-type Buck circuits, and each voltage conversion circuit independently performs maximum power point tracking calculation on one photovoltaic cell string, so that each level of voltage conversion circuit outputs the maximum power of the corresponding level of photovoltaic cell string.

The method further includes, in a power optimizer configured for each photovoltaic module: a second switch provided in any one or more of the voltage converting circuits thereof, in one of the voltage converting circuits with the second switch: the output capacitor and the second switch are connected in series between a group of voltage output ends of the voltage conversion circuit.

In the method, at the stage that the carrier sending module configured for each photovoltaic module sends the communication carrier: the second switch is controlled by a processor configured to the photovoltaic module to be switched into a turn-off state so as to break a serial branch formed by respective output capacitors of voltage conversion circuits at different levels in a power optimizer matched with the photovoltaic module;

and the second switch is controlled by the processor to be switched into a switch-on state until the phase that the carrier sending module sends the communication carrier is finished.

In the above method, each photovoltaic module is further provided with a power module for providing a stable voltage, and the power module converts the voltage generated by each level of photovoltaic cell string of the photovoltaic module into a stable voltage and outputs the stable voltage, wherein the voltage generated by each level of photovoltaic cell string is respectively transmitted to the power module through a diode; and/or the power supply module converts the output voltage of a power optimizer which is configured corresponding to the photovoltaic module into stable voltage and outputs the stable voltage.

In the method, at the stage that the carrier sending module configured for each photovoltaic module sends the communication carrier: and the power supply module for limiting the configuration of each photovoltaic module only collects and converts the voltage generated by each stage of photovoltaic cell string of the photovoltaic module into stable voltage for output, and does not collect the output voltage of the power optimizer.

In the method, an inverter is used to convert the total output voltage output by the photovoltaic modules in series connection into alternating current, and the inverter comprises a carrier detection module; when at least one processor of the photovoltaic module configuration receives first data transmitted by the wireless communication module of the photovoltaic module configuration, the processor of the photovoltaic module configuration forms second data representing data information of the first data on a transmission line by controlling the carrier sending module of the photovoltaic module configuration; and the carrier detection module of the inverter configuration extracts the second data to realize information interaction between the inverter and at least one part of the photovoltaic modules.

In the method, the specified parameters of the photovoltaic cell are collected by a data collection device with a carrier detection module; the processor of the photovoltaic component configuration forms communication carrier data representing the designated parameters on a transmission line by controlling the carrier sending module of the photovoltaic component configuration; the data acquisition equipment extracts the communication carrier representing the designated parameter on the transmission line by using a carrier detection module, so as to acquire the designated parameter information of the photovoltaic cell.

In one embodiment, the invention provides a photovoltaic power optimization system having a plurality of photovoltaic modules connected in series: each photovoltaic module comprises a first-stage photovoltaic cell string or a multi-stage photovoltaic cell string, each photovoltaic module is also provided with a power optimizer, each power optimizer comprises a first-stage or multi-stage voltage conversion circuit, and each stage of voltage conversion circuit performs voltage boosting or voltage reduction conversion on the voltage generated by the corresponding first-stage photovoltaic cell string to output; the output voltages of the power optimizers configured for the photovoltaic assemblies are added together to serve as the total output voltage of the photovoltaic assemblies.

In an alternative embodiment, all of the photovoltaic modules are configured with wireless communication modules. Therefore, a user can utilize the wireless communication device to send data to the wireless communication modules configured for all the photovoltaic modules respectively, so as to realize direct communication between the wireless communication device and all the photovoltaic modules, but if the wireless communication modules configured for a part of the photovoltaic modules are shielded by signals or the wireless communication function of the wireless communication modules fails/is not good, the photovoltaic modules receiving the data through the wireless communication modules can retransmit the data (using the carrier sending modules with the photovoltaic modules) to other photovoltaic modules which cannot receive the data through the wireless communication modules (using the carrier receiving modules with the photovoltaic modules to receive the data).

The photovoltaic power optimization system further comprises an inverter for converting direct current output by the photovoltaic modules in series connection into alternating current, and data interaction is realized between a wireless communication device integrated by the inverter and the wireless communication module.

The photovoltaic power optimization system further comprises a wireless communication device matched with the photovoltaic module for use, wherein the wireless communication device is an independent terminal device matched with the photovoltaic module for use, and data interaction is realized between the terminal device and the wireless communication module.

In the photovoltaic power optimization system, the voltage conversion circuits are Buck-type Buck circuits, and each voltage conversion circuit independently performs maximum power point tracking calculation on one photovoltaic cell string, so that each level of voltage conversion circuit outputs the maximum power of the corresponding level of photovoltaic cell string.

The photovoltaic power optimization system further includes, in a power optimizer configured for each photovoltaic module: a second switch provided in any one or more stages of the voltage converting circuit thereof, in the voltage converting circuit with the second switch: the output capacitor and the second switch are connected in series between a group of output ends of the voltage conversion circuit.

In the photovoltaic power optimization system, at the stage that the carrier sending module configured for each photovoltaic module sends the communication carrier: the second switch is controlled by a processor configured to the photovoltaic module to be switched into a turn-off state so as to break a serial branch formed by respective output capacitors of voltage conversion circuits at different levels in a power optimizer matched with the photovoltaic module; and the second switch is controlled by the processor to be switched to a switch-on state until the phase that the carrier sending module sends the communication carrier is finished.

In the above photovoltaic power optimization system, each photovoltaic module is further configured with a power module for providing a stable voltage, and the power module converts the voltage generated by each level of photovoltaic cell string of the photovoltaic module into a stable voltage and outputs the stable voltage, wherein the voltage generated by each level of photovoltaic cell string is respectively transmitted to the power module through a diode; and/or the power supply module converts the output voltage of a power optimizer which is configured corresponding to the photovoltaic module into stable voltage and outputs the stable voltage.

In the photovoltaic power optimization system, at the stage that the carrier sending module configured for each photovoltaic module sends the communication carrier:

and the power supply module for limiting the configuration of each photovoltaic module only collects and converts the voltage generated by each stage of photovoltaic cell string of the photovoltaic module into stable voltage for output, and does not collect the output voltage of the power optimizer.

The photovoltaic power optimization system further comprises an inverter for converting direct current output by the photovoltaic modules in series connection into alternating current, wherein the inverter comprises a carrier detection module.

When at least one processor of the photovoltaic module configuration receives first data transmitted by the wireless communication module of the photovoltaic module configuration, the processor of the photovoltaic module configuration forms second data representing the first data on a transmission line by controlling the carrier sending module of the photovoltaic module configuration.

The photovoltaic power optimization system also comprises a data acquisition device with a carrier detection module, wherein the data acquisition device is used for acquiring the specified parameters of the photovoltaic cell; the processor of the photovoltaic component configuration forms communication carrier data representing the designated parameters on a transmission line by controlling the carrier sending module of the photovoltaic component configuration; the data acquisition equipment extracts the communication carrier representing the designated parameter on the transmission line by using a carrier detection module, so as to acquire the designated parameter information of the photovoltaic cell.

The invention discloses a photovoltaic power optimization system, which is provided with a plurality of photovoltaic modules connected in series, wherein: each photovoltaic module comprises one-stage or multi-stage photovoltaic cell strings, each photovoltaic module is also provided with a power optimizer, each power optimizer comprises one-stage or multi-stage voltage conversion circuits, and each stage of voltage conversion circuit performs voltage boosting or voltage reducing conversion on the voltage generated by the corresponding one-stage photovoltaic cell string to output; the output voltages of the power optimizers configured for the photovoltaic assemblies are added together to serve as the total output voltage of the photovoltaic assemblies; the photovoltaic module is provided with a carrier sending module and/or a wireless communication module to realize data sending, and the carrier sending module is used for forming a communication carrier on a transmission line which is connected with the photovoltaic module in series; and the photovoltaic module is provided with a carrier detection module and/or a wireless communication module to realize data reception, and the carrier detection module is at least used for extracting communication carriers on the transmission line.

In the above photovoltaic power optimization system, each voltage conversion circuit in the power optimizer that performs maximum power point tracking includes: a first input terminal, a second input terminal, and first and second output nodes for providing output voltages, respectively connected to the positive terminal and the negative terminal of the corresponding primary photovoltaic cell string, wherein the output capacitance of each voltage conversion circuit is connected between its first and second output nodes, a first switch and an inductor are connected between the first input terminal and the first output node, the second input terminal and the second output node are coupled together, and a second switch or a freewheeling diode is connected between an interconnection node between the first switch and the inductor and the second output node.

A first input terminal, a second input terminal, and first and second output nodes for providing output voltages, respectively connected to the positive terminal and the negative terminal of the corresponding primary photovoltaic cell string, wherein the output capacitance of each voltage conversion circuit is connected between its first and second output nodes, a first switch and an inductor are connected between the second input terminal and the second output node, the first input terminal and the first output node are coupled together, and a second switch or a freewheeling diode is connected between an interconnection node between the first switch and the inductor and the first output node;

the power optimizer also comprises a second switch arranged in any one or more stages of voltage conversion circuits, and in any one of the voltage conversion circuits with the second switch: the output capacitor and the second switch are connected in series between the first and second output nodes of the voltage conversion circuit of this stage.

In the invention, the photovoltaic optimizers can communicate with each other, so that the working state of each photovoltaic assembly (even at the level of a cell string) and the voltage of the whole photovoltaic system are known. The inverter realizes the detection of each photovoltaic component through a Rogowski coil, a band-pass filter, demodulation and the like, and the circuit also integrates an arc detection function. The inverter can also realize the issue of commands to the photovoltaic optimizer, the photovoltaic optimizer can be intelligently shut down by adjusting interference current, and the photovoltaic optimizer can be informed of intelligent startup through slow loading voltage. In addition, the inverter informs the photovoltaic optimizer of shutdown or entering a protection mode in a current mode, and the circuit for loading current can also be used as a discharge circuit of the internal capacitance of the inverter. According to the invention, a long photovoltaic string mode can be realized, namely each photovoltaic optimizer controls the output voltage thereof, so that each whole photovoltaic string can be connected with more photovoltaic components in series, and the condition that the inverter needs more input voltage margin due to overhigh output voltage under the condition of low-temperature open circuit of the traditional photovoltaic string is avoided.

These solutions have advantages such as: the power generation efficiency of the whole power generation system is improved, negative factors such as local photovoltaic damage and shielding or inconsistency of photovoltaic cells and installation inconsistency have no influence on the power generation efficiency of the system, the cascade optimization of the cell pieces is realized, the system efficiency is deeply excavated, and the observability of various parameters of each cell component is achieved in a communication mode. The safety of the photovoltaic system is also realized, when a fault or maintenance occurs, the photovoltaic string can be switched off, and the output voltage is zero. The number of each photovoltaic group string in series connection is increased, and the wiring cost of the system is saved. The hot spot resistance of the photovoltaic module is improved, so that the service life of the cell is prolonged.

Drawings

The features and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the following drawings:

fig. 1 is a schematic diagram of a plurality of photovoltaic cells connected in series and then in parallel to power an inverter.

Figure 2 is a schematic diagram of an additional module per photovoltaic cell assembly.

Fig. 3 is a schematic diagram of a plurality of photovoltaic modules connected in series and communicating with a wireless transceiver module of an inverter.

Fig. 4 is a schematic diagram of a plurality of photovoltaic modules connected in series and communicating with a single terminal device.

FIGS. 5-7 are schematic diagrams of power optimizer alternatives for each photovoltaic module configuration.

Fig. 8 is a schematic diagram of a plurality of photovoltaic modules connected in series to achieve data transmission completely through wireless communication.

Detailed Description

Referring to fig. 1, photovoltaic modules PV _1, PV _2, and … … PV _ N (N is a natural number greater than 1) connected in series are combined together to form a photovoltaic string group 101, and a plurality of such photovoltaic string groups 101 are connected in parallel to generate the dc voltage required by the inverter 170. Open circuitThe module 151 is connected between the positive pole of the photovoltaic string 101 and an energy storage capacitor C of the inverter 170_DCBetween the negative pole of the photovoltaic string 101 and the capacitor C, the disconnection module 152_DCBetween the second ends. The photovoltaic string 101 may be an energy storage capacitor C when the

shutdown modules

151 and 152 are turned on_DCSupplying power, otherwise the energy-storage capacitors C when they are disconnected_DCThe voltage source cannot be extracted from the photovoltaic string 101 side. In the field of photovoltaic inversion, a direct-current voltage source generated by a photovoltaic module needs to be converted into alternating current to realize grid connection, a photovoltaic inverter 170 is used for converting direct-current electric energy provided by a photovoltaic string group 101 into alternating-current electric energy so as to meet the requirements of alternating-current load or equipment power supply and grid connection, and the inverter usually has a single-phase or three-phase or even at most equal inversion mode. For the purpose of simply explaining the role of the inverter, fig. 1 exemplarily shows a three-phase full-bridge main power conversion circuit 171 (which may be a single-phase or two-phase or multi-phase), a conventional EMC filter used in a previous stage of the three-phase full-bridge main power conversion circuit 171, a three-phase LC filter used in a next stage of the three-phase full-bridge main power conversion circuit 171, and the like are conventional means, and the conversion circuit 171 may convert a capacitor C in the inverter into a capacitor C_DCThe stored dc voltage is converted into ac voltage, wherein the switching tubes of the converting circuit 171, which constitute the inverter bridge, are mainly driven and controlled by a pulse width modulation signal PWM sent from a controller not shown in the figure. Since the inverter circuit 171 is used to convert dc power into ac power, alternative types are well known in the art and will not be described in detail.

Referring to fig. 2, the differences from the conventional photovoltaic modules PV _1, PV _2, … … PV _ N in fig. 1 are: first, each PV module PV _ N is equipped with an add-on module COM _ N with communication and driving capabilities, and further, each PV module PV _ N is equipped with a power optimizer OP _ N at the cell string level as mentioned later.

Referring to fig. 2, in a photovoltaic power optimization system according to the present application, similar to the conventional solution, there are a plurality of photovoltaic modules PV _1, PV _2, … … PV _ N connected in series, and they are connected in series to form a photovoltaic string group 101, and one or more photovoltaic string groups 101 connected in parallel in the whole photovoltaic power optimization system supply power to the inverter 170.

Referring to fig. 3, each photovoltaic module is provided with a carrier transmission module 130, and the carrier transmission module 130 is mainly used to form a communication carrier on the transmission line LAN connecting the photovoltaic modules PV _1, PV _2, … … PV _ N in series.

Referring to fig. 3, each photovoltaic module is configured with a carrier sensing module 131, and the carrier sensing module 131 is at least used for extracting a communication carrier on the transmission line LAN. The carrier detecting module 131 has various schemes, in this application, the carrier detecting module 131 includes a current sensor 131a (in this application, the current sensor may also be referred to as a current detecting unit or a current transformer module, etc.) and a filter 131b, the current sensor 131a may be a hall sensor or an air-core coil sensor, a codec, a shunt, etc., the current sensor 131a is mainly used for monitoring current information on the transmission line LAN, such as a power frequency signal or a harmonic component signal, or a high-frequency pulse/transient current like a surge, and an arc signal may also be detected. The filter 131b may be a band pass filter, etc., and is mainly used to discriminate and extract a predetermined communication carrier signal having a specific frequency range from the current information detected by the current sensor 131a in the present invention. That is, the band pass filter 102 can detect different information from the current information depending on the selection of the band pass range, for example, the upper frequency limit of the communication carrier is generally lower than the lower frequency limit of the arc level.

Referring to fig. 3, at least a portion of the photovoltaic modules (e.g., PV _ N) are configured with wireless communication modules 133, and while theoretically all of the photovoltaic modules PV _1, PV _2, … … PV _ N could be configured with wireless communication modules 133, for cost and communication optimization considerations, we use wireless communication modules 133 only in one portion of the photovoltaic modules, and do not use wireless communication modules in another portion of the photovoltaic modules (e.g., PV _ 1).

Referring to fig. 3, one of our objectives is: such that at least a portion of the photovoltaic modules (e.g., PV _ N) receive or transmit first data embodied in the form of wireless communications via the configured wireless communication module 133. In the embodiment of fig. 3, the wireless communication device 173 is integrated in the inverter 170, and it is noted that the wireless communication module 133 or the wireless communication device 173 mentioned herein may adopt any existing wireless communication scheme such as WIFI, Zigbee, 433MHZ communication, infrared, bluetooth, GPS, etc. The wireless communication device 173 may be a human-operated device that sends out the first data, when the photovoltaic module PV _ N receives the first data through the wireless communication module 133, the processor 132 configured to the photovoltaic module PV _ N receives the first data transmitted by the wireless communication module 133, and once the processor 132 recognizes that the first data is data that needs to be forwarded to another photovoltaic module (e.g., PV _1), the processor 132 forms the second data representing the data information of the first data on the transmission line LAN through the carrier sending module 130 configured to the photovoltaic module PV _ N, and the second data is in the form of a carrier carried on the transmission line LAN. The photovoltaic module PV _1 is configured with a carrier sensing module 131, and the carrier sensing module 131 is configured to extract a communication carrier identifying the second data on the transmission line LAN.

Thus, the trend of the signal is: the wireless signal (first data) sent by the wireless communication device 173 is captured by the wireless communication module 133 configured by some photovoltaic modules PV _ N, then the processor 132 configured by photovoltaic modules PV _ N recognizes the meaning of the first data transmitted by the wireless communication module 133, when the processor 132 recognizes that the first data needs to be forwarded to those photovoltaic modules PV _1 not configured with the wireless communication module 133, the processor 132 configured by photovoltaic modules PV _ N actively drives the carrier transmission module 130 to form a carrier current carrying the second data on the transmission line LAN, and the processor 132 assigns the second data to have a specified frequency range. The carrier detecting module 131 matched to the photovoltaic module PV _1 without the wireless communication module 133 monitors the current information on the transmission line LAN through the current sensor 131a, and the filter 131b matched to the photovoltaic module PV _1 is further configured to extract a predetermined communication carrier signal (e.g., a second data signal on the LAN) with a specified frequency range from the current information monitored by the current sensor 131a, and the second data is further transmitted to the processor 132 configured to the photovoltaic module PV _1, and the processor 132 reads the meaning of the second data. For example, the first data is a power-on or power-off instruction sent by the wireless communication device 173, the processor 132 of the photovoltaic module PV _ N not only turns on or off the optimizer OP _ N itself, but also forwards the power-on or power-off instruction to other photovoltaic modules, for example, when the photovoltaic module PV _1 receives the second data information, the processor 132 of the photovoltaic module PV _1 also instructs the optimizer OP _1 to turn on or off the photovoltaic module PV _1 because the second data represents the information of the first data.

Referring to fig. 4, the difference from fig. 3 is that the wireless communication device 173 of fig. 3 for sending the first data is integrated with the inverter 170, while in fig. 4, the first data is sent by another wireless communication device 273, and the wireless communication device 273 is a separate terminal device used with the photovoltaic module, and the terminal device is similar to a mobile phone/remote controller, etc. and can send out a wireless communication signal that can be recognized by the wireless communication module 133.

Referring to fig. 4, as an option, the inverter 170 also includes a carrier detection module 131, the carrier detection module 131 of the inverter 170 monitors the current information on the transmission line LAN through the current sensor 131a, and the filter 131b of the inverter 170 is further configured to extract a preset communication carrier signal (e.g., a second data signal on the LAN) with a specified frequency range from the current information monitored by the current sensor 131a, and the second data is further transmitted to a non-illustrated processor of the inverter 170, and the processor reads the meaning of the second data. At this time, the photovoltaic module PV _ N is equivalent to forwarding a power-on or power-off command to the inverter 170, and since the second data represents the information represented by the first data when the inverter 170 receives the second data information, the processor of the inverter 170 may also instruct itself to power on or power off, for example, may also instruct the

circuit breakers

151 and 152 in fig. 1 to open.

Referring to fig. 5, a first cell string ST1 of a PV module PV _ N generates a desired voltage output by using a first BUCK-type BUCK1 conversion circuit, AN inductor L1 and a capacitor C1 in the BUCK1 circuit constitute a low-pass filter, a first input node AN1 of the BUCK1 circuit is connected to AN anode of the cell string ST1, and a second input node AN of the BUCK1 circuitCA1 is connected to the cathode of ST1, and switch S11 and inductor L1 are connected in series at first input node AN1 and first output node N of BUCK1 circuit_B1-1In the meantime. One end of switch S11 is connected to a first input node AN1 of the BUCK1 circuit, but the opposite end of switch S11 is connected to a second input node of the BUCK1 circuit (or a second output node N of the BUCK1 circuit)_B1-2) With another switch S12 connected therebetween. The output capacitor C1 is connected to the first output node N of the BUCK1 circuit_B1-1And a second output node N_B1-2In the meantime. The basic principle of the conversion circuit is as follows: the first and second inputs of the BUCK1 circuit draw a supply voltage from between the anode and cathode of the first battery string ST1, during a switching cycle, switch S11 is turned on and off S12, inductor L1 increases current and charges capacitor C1, switch S11 is turned off and on S12, inductor L1 decreases current and begins to discharge energy, and S12 is turned on to freewheel. The BUCK1 converter is used to realize MPPT for maximum power point tracking in the present invention, and since MPPT is known in the art, detailed descriptions thereof are omitted. The maximum power point tracking can be realized by the processor 132 driving the switches S11-S12, S21-S22, and S31-S32.

Referring to fig. 5, a second cell string ST2 of the PV module PV _ N generates a desired voltage output by using a second BUCK-type BUCK2 conversion circuit, AN inductor L2 and a capacitor C2 in the BUCK2 circuit constitute a low-pass filter, a first input node AN2 of the BUCK2 circuit is connected to AN anode of the cell string ST2, a second input node CA2 of the BUCK2 circuit is connected to a cathode of the ST2, and a switch S21 and AN inductor L2 are connected in series at the first input node AN2 and a first output node N of the BUCK2 circuit_B2-1In the meantime. One end of the switch S21 is connected to a first input node AN2 of the BUCK2 circuit, but the opposite end of the switch S21 is connected to a second input node of the BUCK2 circuit (or a second output node N of the BUCK2 circuit)_B2-2Because of nodes CA2 and node N_B2-2Connected) is connected to another switch S22. The output capacitor C2 is connected to the first output node N of the BUCK2 circuit_B2-1And a second output node N_B2-2In the meantime.

Referring to fig. 5, the third cell string ST3 of the photovoltaic module PV _ N utilizes the third cell stringThree BUCK-type BUCK3 conversion circuits are used for generating a desired voltage output, AN inductor L3 and a capacitor C3 in a BUCK3 circuit form a low-pass filter, a first input node AN3 of a BUCK3 circuit is connected to the anode of a battery string ST3, a second input node CA3 of a BUCK3 circuit is connected to the cathode of the battery string ST3, and a switch S31 and AN inductor L3 are connected in series at a first input node AN3 and a first output node N of the BUCK3 circuit_B3-1In the meantime. One end of switch S31 is connected to a first input node AN3 of the BUCK3 circuit, but the opposite end of switch S31 is connected to a second input node of the BUCK3 circuit (or a second output node N of the BUCK3 circuit)_B3-2Because of nodes CA3 and node N_B3-2Connected) is connected to another switch S32. The output capacitor C3 is connected to the first output node N of the BUCK3 circuit_B3-1And a second output node N_B3-2In the meantime.

In the present application, the inventive spirit of the present application is explained by taking three battery strings ST1 to ST3 and three voltage conversion circuits BUCK1 to BUCK3 as an example for a while. Wherein, the second output node N of the BUCK1 circuit_B1-2And a first output node N of the BUCK2 circuit_B2-1Connected, second output node N of BUCK2 circuit_B2-2And a first output node N of the BUCK3 circuit_B3-1The capacitors C1, C2 and C3 are connected in series at the first output node N of the BUCK1 circuit_B1-1And a second output node N of the BUCK3 circuit_B3-2In the meantime. The carrier transmission module 130 is also connected to the first output node N of the BUCK1 circuit_B1-1And a second output node N of the BUCK3 circuit_B3-2E.g. switch S_BAnd a capacitor C_BAnd a resistor R_BIs connected in series at a first output node N_B1-1And a second output node N_B3-2And in a positional relationship with the switch S_BAnd a capacitor C_BAnd a resistor R_BThe positions of any two of the three can be changed arbitrarily, and a resistor R can be arranged_CConnected in parallel to a capacitor C_BAt both ends of the same.

Referring to fig. 5, an output capacitor C2 and a switch S_WIConnected in series at a first output node N of the BUCK2 circuit_B2-1And a second output node N_B2-2In the meantime. In other placesIn an alternative embodiment, an output capacitor C1 and a switch S may also be provided_WIConnected in series at a first output node N of the BUCK1 circuit_B1-1And a second output node N_B1-2Between, or an output capacitor C3 and a switch S are provided_WIConnected in series at a first output node N of the BUCK3 circuit_B3-1And a second output node N_B3-2In the meantime. That is, switch S_WIOptionally connected in series with one of C1, C2 and C3. In other alternative embodiments, it is even possible to use the first output node N of BUCK1_B1-1And a second output node N_B1-2Between C1 and the first switch S_WIAlso at the first output node N of BUCK2_B2-1And a second output node N_B2-2A capacitor C2 and a second switch S connected in series between_WIAt the same time at the first output node N of BUCK3_B3-1And a second output node N_B3-2A capacitor C3 and a third switch S are connected in series between_WI。

Referring to fig. 3 to 4, each PV module PV _ N includes multiple levels of PV cell strings ST1 to ST3, each PV module PV _ N is configured with a power optimizer OP _ N, each power optimizer OP _ N includes multiple levels of voltage conversion circuits BU1 to BU3, each voltage conversion circuit BU1 performs voltage boosting or voltage dropping conversion on the voltage generated by the corresponding one-level PV cell string ST1 for output, each voltage conversion circuit BU2 performs voltage boosting or voltage dropping conversion on the voltage generated by the corresponding one-level PV cell string ST2 for output, each voltage conversion circuit BU3 performs voltage boosting or voltage dropping conversion on the voltage generated by the corresponding one-level PV cell string ST3 for output, the photovoltaic modules PV _1, PV _2, and … … PV _ N connected in series are respectively and correspondingly configured with power optimizers OP _1, OP _2, and … … OP _ N, and voltages V output by the optimizers OP _1, OP _2, and … … OP _ N._OUT1+V_OUT2+……V_OUTNAdded together as the total output voltage of the plurality of photovoltaic modules PV _1, PV _2, … … PV _ N. The voltage conversion circuit here may employ the BUCK circuit of fig. 5.

Referring to fig. 3 to 4, in the power optimizer OP _ N, the voltage conversion circuit BU1 performs voltage conversion with respect to the voltage generated by the corresponding primary photovoltaic cell string ST1 and outputs the voltage to one output capacitor C1, the voltage conversion circuit BU2 performs voltage conversion with respect to the voltage generated by the corresponding primary photovoltaic cell string ST2 and outputs the voltage to one output capacitor C2, and the voltage conversion circuit BU3 performs voltage conversion with respect to the voltage generated by the corresponding primary photovoltaic cell string ST3 and outputs the voltage to one output capacitor C3. Capacitors C1 to C3 of the voltage conversion circuits BU1 to BU3 of the power optimizer OP _ N are connected in series. If it is defined that each stage of the voltage converting circuit in the power optimizer OP _ N has a first output node and a second output node, the output capacitor C of the voltage converting circuit is connected between the first output node and the second output node thereof, and the first output node of any subsequent stage of the voltage converting circuit is connected to the second output node of the previous stage of the voltage converting circuit thereof, so that the output voltages of the power optimizer OP _ N are provided by the voltages superposed on the output capacitors C1 to C3 connected in series by C1 to C3 in series. And a carrier sending module 130 configured to the photovoltaic module OP _ N is connected in parallel with the output capacitors C1-C3 connected in series, that is, the carrier sending module 130 is connected between the first output node of the first-stage voltage conversion circuit and the second output node of the last-stage voltage conversion circuit in the multi-stage voltage conversion circuits of the power optimizer OP _ N.

Referring to fig. 6, the difference from fig. 5 is that: the switch S12 of the BUCK1 circuit is replaced by a diode D12, the anode of the diode D12 is connected to the cathode of ST1 and the second output node N of the BUCK1 circuit_B1-2The cathode of diode D12 is connected to the node interconnected between switch S11 and inductor L1. Switch S22 of BUCK2 circuit is also replaced by diode D22, the anode of diode D22 is connected to the cathode of ST2 and the second output node N of BUCK2_B2-2The cathode of diode D22 is connected to the node interconnected between switch S21 and inductor L2. Switch S32 of BUCK3 circuit is also replaced by diode D32, the anode of diode D32 is connected to the cathode of ST3 and the second output node N of BUCK3_B3-2The cathode of diode D32 is connected to the node interconnected between switch S31 and inductor L3.

Referring to fig. 7, the difference from fig. 5 is that: the structure of the BUCK circuit is slightly changed. The concrete expression is as follows: BUCK1 electricityThe first input node AN1 of the circuit is connected to the anode of the battery string ST1, the second input node CA1 of the BUCK1 circuit is connected to the cathode of ST1, and the switch S11 and the inductor L1 are connected in series between the second input node CA1 and the second output node N of the BUCK1 circuit_B1-2In between. One end of switch S11 is connected to the second input node CA1 of the BUCK1 circuit, but the opposite end of switch S11 is connected to the first input node of the BUCK1 circuit (or the first input node AN1 of the BUCK1 circuit, since node AN1 and node N_B1-1Connected) to a diode D12, the anode of diode D12 is connected to the node interconnecting the switch S11 and the inductor L1, and the cathode of diode D12 is connected to the first input node AN 1. The capacitor C1 is connected to the first output node N of BUCK1_B1-1And a second output node N_B1-2In between.

Referring to FIG. 7, similarly, switch S21 and inductor L2 are connected in series at a second input node CA2 and a second output node N of the BUCK2 circuit_B2-2And (3) removing the solvent. One end of the switch S21 is connected to the second input node CA2 of BUCK2, and the opposite end of the switch S21 is connected to the first input node AN2 of the BUCK2 circuit (or the second output node N of the BUCK2 circuit)_B2-1Because node AN2 and node N_B1-1Connected) to a diode D22, the anode of diode D22 being connected to the node interconnecting the switch S21 and the inductor L2, and the cathode of diode D22 being connected to the first input node AN 2. The capacitor C2 is connected to the first output node N of BUCK2_B2-1And a second output node N_B2-2In between.

Referring to FIG. 7, similarly, switch S31 and inductor L3 are connected in series at a second input node CA3 and a second output node N of the BUCK3 circuit_B3-2And (3) removing the solvent. One end of the switch S31 is connected to the second input node CA3 of BUCK3, and the opposite end of the switch S31 is connected to the first input node AN3 of the BUCK3 circuit (or the second output node N of the BUCK3 circuit)_B3-1Because node AN3 and node N_B3-1Connected) to a diode D32, the anode of diode D32 being connected to the node interconnecting the switch S31 and the inductor L3, and the cathode of diode D32 being connected to the first input node AN 3. The capacitor C3 is connected to the first output node N of BUCK3_B3-1And a second output node N_B3-2In the meantime.

Referring to fig. 7, an output capacitor C3 and a switch S_WIConnected in series at a first output node N of the BUCK3 circuit_B3-1And a second output node N_B3-2In the meantime. In other alternative embodiments, an output capacitor C1 and a switch S may also be provided_WIConnected in series at a first output node N of the BUCK1 circuit_B1-1And a second output node N_B1-2Between, or an output capacitor C2 and a switch S are provided_WIConnected in series at a first output node N of the BUCK2 circuit_B2-1And a second output node N_B2-2In the meantime. That is, switch S_WIOptionally connected in series with one of C1, C2 and C3. In other alternative embodiments, it is even possible to use the first output node N of BUCK1_B1-1And a second output node N_B1-2A capacitor C1 and a first switch S connected in series between_WIWhile also being at the first output node N of BUCK2_B2-1And a second output node N_B2-2A capacitor C2 and a second switch S connected in series between_WIAt the same time at the first output node N of BUCK3_B3-1 and a second output node N_B3-2A capacitor C3 and a third switch S are connected in series between_WI。

Referring to the embodiments of fig. 5 to 7, the switches S11/S21/S31 and S12/S22/S32 may also be referred to as switches or synchronous switches in this application, the diodes D12/D22/D32 may also be referred to as freewheeling diodes in this application, and the diodes D12/D22/D32 in fig. 7 may also be replaced by three switches, respectively, as long as the requirement of the conventional BUCK circuit can be satisfied. Referring to the embodiments of fig. 5 to 7, the photovoltaic optimizer of the present application can be summarized as follows: in the N-level photovoltaic cell string and the N-level voltage conversion circuit of a certain photovoltaic module, any K-th level voltage conversion circuit comprises an output capacitor C_KThe natural number K satisfies that N is more than or equal to K and more than or equal to 1, and the capacitor C of any K-th level voltage conversion circuit_KConnected to the first output node N of the Kth stage voltage conversion circuit_BK-1And a second output node N_BK-2In the meantime. The voltage provided by the photovoltaic cell string of the Kth stage is correspondingly output at a first output node N of the voltage conversion circuit of the Kth stage_BK-1And a firstTwo output nodes N_BK-2And (3) removing the solvent. In addition, a first output node of any voltage conversion circuit of the next stage is connected with a second output node of the adjacent voltage conversion circuit of the previous stage, so that the first output node N of the first voltage conversion circuit of the first stage can be connected with the second output node N of the voltage conversion circuit of the next stage_B1-1And a second output node N of a last Nth-stage voltage conversion circuit at the end_BN-2In this regard, the overall output voltage of the N-level photovoltaic cell string is generated and provided, which is essentially the output voltage of an optimizer, since the N-level voltage conversion, here matched to a photovoltaic module, is essentially a component of an optimizer. The total number of photovoltaic cell strings in a photovoltaic module is equal to the total number of voltage conversion circuits in an optimizer. Viewed from the outside of the photovoltaic module, the first output node N of the first-stage voltage conversion circuit_B1-1One end connected with the second output node N of the Nth stage voltage conversion circuit_BN-2The other end of the connection can be regarded as a pair of voltage output ports of the photovoltaic optimizer.

In other alternative embodiments, the BUCK circuit can be replaced by a BUCK-BOOST BUCK/BOOST circuit, where the BUCK-BOOST circuit can also implement the MPPT operation. In short, the BUCK circuit in fig. 5 to 7 can be replaced by any voltage conversion circuit, which can input the voltage between the positive and negative electrodes of any battery string, perform maximum power point tracking, and output the voltage on the output capacitor between a set of output terminals of the voltage conversion circuit.

Referring to fig. 3 to 5, the carrier transmitting module 130 at least includes switches S connected in series_BAnd a capacitor C_BAt the stage of transmitting the communication carrier by the carrier transmission module 130, the switch S is turned on_BThe processor 132, configured by the photovoltaic module OP _ N, controls the switching between the off and on states so as to form a data-carrying carrier current on the transmission line LAN. In the preferred embodiment, it is preferable that the carrier transmitter module 130 includes switches S connected in series_BAnd a capacitor C_BAnd a resistor R_BAnd a resistor R is also provided_CConnected in parallel to a capacitor C_BTwo ends. In the presence of by-pass electricityContainer C_BA bypass resistor R_BAnd switch S_BIn the communication circuit of (3), the switch S may be held first_BIn the off state, if the processor 132 tries to exchange information with the outside, the driving signal sent by the processor 132 rapidly jumps from the first logic state (e.g. low level) to the second logic state (e.g. high level) and then returns to the first logic state, so that the switch S, which is switched on under the high level driving, is switched on_BIs turned on and off. Or the driving signal sent by the processor 132 rapidly jumps from the first logic state (e.g. high level) to the second logic state (e.g. low level) and then returns to the first logic state, so that the switch S, which is switched on under the low level driving_BIs turned on and off, the switch S_BThe off-on-off process of (a) may be repeated multiple times. Can be considered to be in the control switch S_BHas a rising or falling edge moment of a nearly transient jump, switches S are closed_BThe harmonic or carrier current flowing through the carrier transmitting module 130 is generated and injected into the first output node N_B1-1Or to a second output node N_B3-2On the transmission line LAN. Various carrier detection modules 131a (e.g., air coil sensor or high frequency transformer, band pass filter, de-encoder) may be used to extract the carrier signal sent by the communication circuit from the current information flowing through the transmission line for demodulation. Such carrier information may be converted into binary symbols for information exchange in accordance with various communication protocols currently specified.

Referring to fig. 5 to 7, taking the photovoltaic module PV _ N as an example, in a stage where the carrier sending module 130 configured to the photovoltaic module PV _ N sends the communication carrier: switch S_WIA processor 132 configured by the photovoltaic module PV _ N controls the switching to the off state to open the serial branch circuit formed by the output capacitors C1-C3 of the voltage conversion circuits BUCK 1-BUCK 3 of each stage in a power optimizer OP _ N matched with the photovoltaic module PV _ N. Until the phase of the carrier sending module 130 sending the communication carrier is finished, the switch S is turned on or off_WIThe processor 132 controls the switch to the on state to recover the path relationship of the serial branch of the output capacitors C1-C3 to avoidThe capacitors C1-C3 absorb carrier signals.

Referring to fig. 5 to 7, taking a photovoltaic module PV _ N as an example, it is configured with a power module (DC/DC circuit) 190 capable of providing a stable voltage source, the power module 190 respectively converts the voltages generated by the photovoltaic cell strings ST1 to ST3 of each stage of the photovoltaic module PV _ N into stable voltages for output, wherein the voltage generated by the photovoltaic cell string ST1 is transmitted to the power module 190 through a diode D1, for example, the positive electrode of the photovoltaic cell string ST1 is connected to the anode of a diode D1, and the cathode of the diode D1 is connected to the voltage input end of the power module 190. The voltage generated by the photovoltaic cell string ST2 is supplied to the power module 190 through the diode D2, and the voltage generated by the photovoltaic cell string ST3 is supplied to the power module 190 through the diode D3. In addition, as an optional solution, the power module 190 may further configure an output voltage of a power optimizer OP _ N (i.e. the voltage V generated by the capacitors C1-C3) corresponding to the photovoltaic module PV _ N_OUTN) Converted into a stable voltage and output. It must be defined that: at the stage when the carrier sending module 130 of the photovoltaic module PV _ N configuration sends the communication carrier: the power module 190 configured to the photovoltaic module PV _ N collects and converts only the voltages generated by the photovoltaic cell strings ST 1-ST 3 at each stage of the photovoltaic module PV _ N into stable voltages and outputs the stable voltages, but does not collect and convert the output voltage V of the power optimizer OP _ N_OUTNThis is because of the switch S_WISwitching the high frequency on and off at this stage applies an additional disturbance noise voltage to the voltage input of the power module 190. The stable voltage generated by the power supply module 190 (which may employ an existing voltage conversion scheme such as a linear power supply or a switching power supply) may be supplied to the filter 131b, the processor 132, the wireless communication module 133, and the like as an operating voltage.

Referring to fig. 3 to 4, the photovoltaic power optimization system further includes a data acquisition device 275 with the carrier detection module 131, the carrier detection module 131 includes a current sensor 131a and a filter 131b, the data acquisition device 275 is configured to acquire parameters (such as voltage, current, temperature, power, etc.) specified by the photovoltaic cell strings ST1 to ST3, and the scheme of the acquisition is as follows: taking PV _ N as an example, the processor 132 configured to collect the specified parameters by using an existing scheme, for example, many MCU processors in the past have their own sensing modules with the specified parameters, or use an auxiliary parameter collecting module to collect the specified parameters, after the processor 132 knows the parameter information, the processor 132 can form or send communication carrier data representing the specified parameters on the transmission line LAN by controlling the carrier sending module 130 configured to PV _ N, and the data collecting device 275 detects and extracts the communication carrier representing the specified parameters on the transmission line LAN by using the carrier detecting module 130 with the specified parameters, so as to collect the specified parameter information of each cell string in the PV _ N.

Referring to the embodiment of fig. 8, slightly different from the embodiments of fig. 3 to 7, each of the photovoltaic modules PV _1 to PV _ N is configured with a wireless communication module 133 for receiving, sending, or receiving and sending data, or may be configured with a carrier sending module 130 at the same time, and then data interaction is realized between the wireless communication device 273 and the wireless communication module 133, and the wireless communication device 273 may be integrated in the inverter 170 or may be a terminal device. At this time, the data can be completely transmitted in a wireless manner, so the carrier sending module 130 and the carrier detecting module 131 can be selected or not selected.

In this application, the data and the like may be user instructions, commands or any other data information.

While the present invention has been described with reference to the preferred embodiments and illustrative embodiments, it is to be understood that the invention as described is not limited to the disclosed embodiments. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above description. It is therefore intended that the appended claims be interpreted as covering all alterations and modifications as fall within the true spirit and scope of the invention. Any and all equivalent ranges and contents within the scope of the claims should be considered to be within the intent and scope of the present invention.

Claims

1. A photovoltaic power optimization system having a plurality of photovoltaic modules connected in series, characterized by:

the photovoltaic module is provided with a carrier sending module and/or a wireless communication module to realize data sending, and the carrier sending module is used for forming a communication carrier on a transmission line which is connected with the photovoltaic module in series;

the photovoltaic module is provided with a carrier detection module and/or a wireless communication module to realize data receiving, and the carrier detection module is at least used for extracting communication carriers on the transmission line;

at least one part of the photovoltaic modules receive or send first data embodied in a wireless communication form through a configured wireless communication module; and/or

The photovoltaic component receives second data embodied in a communication carrier form on the transmission line through a configured carrier detection module;

a first type of component among the photovoltaic components is configured with a wireless communication module, and a second type of component among the photovoltaic components is not configured with the wireless communication module; and is

When the processor configured by the first type of component receives first data transmitted by the wireless communication module, the processor forms second data representing the first data on a transmission line by controlling the carrier transmitting module configured by the first type of component; and

the carrier sensing module configured by the second type of component extracts the second data and transmits the second data to the processor of the second type of component.

2. The photovoltaic power optimization system of claim 1, wherein the carrier transmission module comprises at least a first switch and a capacitor in series with each other;

3. The photovoltaic power optimization system of claim 1, wherein the carrier sensing module comprises a current detection unit for monitoring current information on the transmission line and a filter for extracting a predetermined communication carrier signal having a specified frequency range from the current information.

4. The photovoltaic power optimization system of claim 2, wherein the carrier transmit module comprises a first switch and a capacitor in series with a first resistor, and further comprising a second resistor connected in parallel across the capacitor.

5. The photovoltaic power optimization system of claim 1, further comprising an inverter for converting dc power output from a plurality of series-connected photovoltaic modules into ac power, wherein the first data is transmitted by a wireless communication device integrated with the inverter.

6. The photovoltaic power optimization system of claim 1, wherein the first data is transmitted by a wireless communication device that is a stand-alone terminal device associated with the photovoltaic module.

7. The photovoltaic power optimization system according to claim 1, wherein each photovoltaic module includes one or more photovoltaic cell strings, and each photovoltaic module is further configured with a power optimizer, each power optimizer includes a plurality of voltage conversion circuits, and each voltage conversion circuit performs voltage boost or voltage buck conversion on the voltage generated by the corresponding one of the photovoltaic cell strings to output;

8. The photovoltaic power optimization system according to claim 7, wherein in each power optimizer, any one of the voltage conversion circuits performs voltage conversion on the voltage generated by the corresponding one-stage photovoltaic cell string to output the voltage on one output capacitor, the respective output capacitors of the voltage conversion circuits in each power optimizer are connected in series, and one of the carrier transmission modules configured for each photovoltaic module is connected in parallel with the output capacitors connected in series.

9. The photovoltaic power optimization system of claim 7, wherein in each power optimizer: any one of the voltage conversion circuits performs voltage boosting or voltage reducing conversion on the voltage generated by the corresponding one-stage photovoltaic cell string and outputs the voltage on one output capacitor, and the output capacitors of the multi-stage voltage conversion circuits in each power optimizer are connected in series, so that the voltage superposed on the output capacitors in series provides the output voltage of each power optimizer.

10. The photovoltaic power optimization system according to claim 7, wherein the voltage conversion circuits are Buck-type Buck circuits, and each voltage conversion circuit performs maximum power point tracking calculation on one photovoltaic cell string independently, so that each voltage conversion circuit outputs maximum power to its corresponding photovoltaic cell string.

11. The photovoltaic power optimization system of claim 9, wherein each photovoltaic module is configured with a power optimizer further comprising:

a second switch provided in any one or more stages of the voltage converting circuit thereof, in the voltage converting circuit with the second switch: the output capacitor and the second switch are connected in series between a group of output ends of the voltage conversion circuit of the stage.

12. The photovoltaic power optimization system according to claim 11, wherein, in the phase in which the carrier transmission module of each photovoltaic module configuration transmits a communication carrier: the second switch is controlled by a processor configured to the photovoltaic module to be switched into a turn-off state so as to break a serial branch formed by respective output capacitors of voltage conversion circuits at different levels in a power optimizer matched with the photovoltaic module;

13. The photovoltaic power optimization system according to claim 7, wherein each photovoltaic module is further configured with a power module for providing a stable voltage, the power module converts the voltage generated by each photovoltaic cell string of the photovoltaic module into a stable voltage and outputs the stable voltage, and the voltage generated by each photovoltaic cell string is respectively transmitted to the power module through a diode;

and/or the power supply module converts the output voltage of a power optimizer which is configured corresponding to the photovoltaic module into stable voltage and outputs the stable voltage.

14. The photovoltaic power optimization system according to claim 13, wherein, in the phase in which the carrier transmission module of each photovoltaic module configuration transmits a communication carrier:

and the power supply module for limiting the configuration of each photovoltaic module only collects and converts the voltage generated by each level of photovoltaic cell string of the photovoltaic module into stable voltage to output, and does not collect the output voltage of the power optimizer.

15. The photovoltaic power optimization system of claim 1, further comprising an inverter for converting dc power output by the series of multiple photovoltaic modules into ac power, the inverter including a carrier detection module; and is

When at least one processor of the photovoltaic module configuration receives first data transmitted by the wireless communication module of the photovoltaic module configuration, the processor of the photovoltaic module configuration forms second data representing the first data on a transmission line by controlling the carrier sending module of the photovoltaic module configuration; and

16. The photovoltaic power optimization system of claim 1, further comprising a data collection device with a carrier sensing module for collecting specified parameters of the cells in the photovoltaic module;

the processor of the photovoltaic component configuration forms communication carrier data representing the designated parameters on a transmission line by controlling the carrier sending module of the photovoltaic component configuration;

the data acquisition equipment extracts the communication carrier representing the designated parameter on the transmission line by using a carrier detection module, so as to acquire the designated parameter information of the battery in the photovoltaic module.

17. A photovoltaic power optimization system having a plurality of photovoltaic modules connected in series, characterized by:

The photovoltaic component receives second data in a communication carrier form on the transmission line through a configured carrier detection module;

first and second type assemblies in the photovoltaic module are all equipped with wireless communication module, and under the condition that wireless communication module of second type assembly is shielded by the signal:

18. A photovoltaic power optimization system having a plurality of photovoltaic modules connected in series, characterized by:

each photovoltaic module comprises one-stage or multi-stage photovoltaic cell strings, each photovoltaic module is also provided with a power optimizer, each power optimizer comprises one-stage or multi-stage voltage conversion circuits, and each stage of voltage conversion circuit performs voltage boosting or voltage reducing conversion on the voltage generated by the corresponding one-stage photovoltaic cell string to output;

the output voltages of the power optimizers configured for the photovoltaic assemblies are added together to serve as the total output voltage of the photovoltaic assemblies;

the photovoltaic module is provided with a carrier sending module and/or a wireless communication module to realize data sending, and the carrier sending module is used for forming a communication carrier on a transmission line which is connected with the photovoltaic module in series; and

each voltage conversion circuit in the power optimizer for executing maximum power point tracking comprises:

a first input terminal, a second input terminal, and first and second output nodes for providing output voltages, respectively connected to the positive terminal and the negative terminal of the corresponding primary photovoltaic cell string, wherein the output capacitance of each voltage conversion circuit is connected between its first and second output nodes, a first switch and an inductor are connected between the first input terminal and the first output node, the second input terminal and the second output node are coupled together, and a second switch or a freewheeling diode is connected between an interconnection node between the first switch and the inductor and the second output node; or