JP2004147465A - Converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the state of the activation of a converter also at its installation, and to reduce power consumption. <P>SOLUTION: A boosting converter 3 comprises an inverter circuit that boosts an input voltage and outputs it, an nonvolatile storage means 43 that stores information about whether the automatic activation of a conversion means is permitted or prohibited when the value of the input voltage exceeds a threshold, a control means 35 that controls the activation of the converter circuit according to the information stored in the storing means, and communication means 41, 42 that transmit information for permitting or prohibiting the automatic activation to the storing means corresponding to a signal received from the outside. The information stored in the storing means 43 is rewritten according to the information transmitted from the communication means 41, 42. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a converter, and more particularly, to start-up control of a converter having power conversion means used for a photovoltaic power generation system or the like.
[0002]
[Prior art]
In recent years, problems such as global warming due to emission of carbon dioxide and the like accompanying the use of fossil fuels, accidents at nuclear power plants, and radioactive contamination by radioactive waste have become serious, and interest in the global environment and energy has been increasing. Under these circumstances, photovoltaic power generation using sunlight, geothermal power generation using geothermal energy, wind power generation using wind power, and the like have been put to practical use worldwide as an inexhaustible and clean energy source.
[0003]
Among them, there are various forms of the solar power generation device using the solar cell according to the output scale from several W to several thousand kW. As a typical system using a solar cell, there is a solar power generation system that converts DC power generated by the solar cell into AC power (orthogonal conversion) by a power converter such as an inverter and supplies the AC power to a commercial power system. .
[0004]
Generally, such a system includes a conversion device such as a DC-DC converter that converts an output voltage of a solar cell into a voltage suitable for an inverter device. There are a configuration in which the converter is integrated with the inverter, and a configuration in which a converter according to the output characteristics of each solar cell is provided separately from the inverter.
[0005]
The latter configuration has the advantage that an optimal converter can be used according to the voltage and power of the solar cell. Further, a converter may be provided for each solar cell string or solar cell module, and the outputs of the converters may be connected in parallel and connected to the inverter.
[0006]
In this case, the difference in the output voltage of the solar cells can be absorbed by the converter, eliminating the need to align the output voltages of the solar cells, as required in a normal system, and has the merit of dramatically increasing the degree of freedom in installation. is there. Also, for example, in a configuration in which the output of a solar cell connected to one converter is small, such as connecting a converter for each solar cell module, the effect of a so-called partial shadow in which some of the solar cells have a shadow is affected by the shadow. Since it appears only in a converter having a small output to which a certain solar cell module is connected, there is an advantage that a decrease in output can be minimized.
[0007]
In such a configuration, wiring work for connecting the output of the converter to the subsequent inverter is required. The installation place of the converter does not necessarily need to be the same place as the inverter, and it can be installed according to the specification of the converter, such as indoor, on the roof side, or outdoors. Further, in the case of installation outdoors, there is a configuration provided near the solar cell or integrally with the solar cell.
[0008]
In such a configuration, it is general that the converter is automatically activated when a predetermined voltage is output after the sun shines on the solar cell. Further, a system configured to start by receiving an external start signal is also known (for example, see Patent Documents 1 and 2).
[0009]
[Patent Document 1]
JP 2000-23365 A
[Patent Document 2]
JP 2001-189476 A
[0010]
[Problems to be solved by the invention]
However, the above configuration causes the following problems.
[0011]
If the converter device is configured to start automatically when a predetermined voltage is output from the solar cell, the output side of the converter may become live when the solar cell is illuminated at the time of construction. And the workability of wiring is reduced due to the consideration of electrical leakage.
[0012]
In order to avoid this, it is conceivable to provide an operation switch for each converter so that it does not automatically start until the wiring work is completed.However, in a system with many converters, it is troublesome to operate the operation switches one by one. The workability is reduced. In particular, in a configuration in which a converter is provided for each solar cell module, the configuration has a very large number of converters in the system, so that the workability is greatly reduced.
[0013]
Further, when the converter is installed outdoors, the operation switch also requires waterproofness and dustproofness, so that the entire system becomes expensive. In particular, in a configuration in which a converter is provided for each solar cell module, it is necessary to use a small waterproof switch, so that the cost is further increased.
[0014]
Further, in a system in which the converter is configured to start by receiving an external start signal, the converter does not operate unless an external start signal is received every time the output from the solar cell is stopped. Therefore, for example, a system for providing a start signal from an inverter connected to the output of the converter has also been proposed. However, in such a system, it is necessary to supply power from a system for a means for providing a start signal. In such a configuration, there is a problem that wasteful power consumption occurs at night or the like when the solar cell does not generate power.
[0015]
The present invention has been made in view of the above situation, and has as its object to control the activation state of the conversion device even during construction and to reduce power consumption.
[0016]
[Means for Solving the Problems]
A conversion device according to one embodiment of the present invention that achieves the above object includes a conversion unit that converts input power and outputs the converted power.
When the value of the input voltage exceeds a predetermined threshold, non-volatile storage means for storing information on whether to allow or prohibit automatic activation of the conversion means,
Control means for controlling activation of the conversion means according to the information stored in the storage means;
Communication means for transmitting information for permitting or prohibiting the automatic activation to the storage means in response to a signal received from outside,
The information stored in the storage unit is rewritten according to the information transmitted from the communication unit.
[0017]
That is, in the present invention, the conversion unit that converts and outputs the input power and the information on whether the automatic activation of the conversion unit is permitted or prohibited when the value of the input voltage exceeds a predetermined threshold are stored. Non-volatile storage means, control means for controlling activation of the conversion means in accordance with information stored in the storage means, and information for permitting or prohibiting automatic activation of the storage means in response to a signal received from outside. And a communication unit for transmitting the information. The conversion device is configured to rewrite the information stored in the storage unit in accordance with the information transmitted from the communication unit.
[0018]
In this way, for example, in a configuration in which a solar cell or the like is used as an input, it is possible to prevent the solar cell from generating power and automatically starting the converter at the time of construction, etc. It can be controlled so as to be in an active state. In addition, for example, the communication unit can transmit information for permitting or prohibiting the automatic activation to the storage unit in response to a signal received via a solar cell or the like as an input unit, so that wasteful power is consumed. Consumption can be reduced.
[0019]
Therefore, it is possible to control the activation state of the conversion device even at the time of construction, and to reduce unnecessary power consumption.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0021]
First, the overall configuration of the conversion device according to the present invention and its components will be described.
[0022]
[Conversion device]
The converting device is a converting means for converting the input electric energy into a desired form, a storing means for storing information on whether the automatic activation of the converting means is prohibited or permitted, and connected to the storing means and received from outside. At least communication means for communicating a signal relating to automatic start, a control circuit for controlling automatic start / stop of the conversion means, optimization of the operating point of the solar cell, an operation mode, etc., a protection circuit, and input / output terminals The output is directly connected to a load, or input to a grid-connected inverter to be grid-connected.
[0023]
The conversion means may be configured by a converter circuit or an inverter circuit as a basic configuration. Also, the input and output may be insulated or non-insulated. A circuit system capable of connecting the outputs of a plurality of converters in parallel is preferable. If the converter circuit is a DC circuit, the output is a direct current, so that the parallelization of the outputs can be easily configured.
[0024]
If the conversion means is constituted by a boost converter circuit having a fixed duty, and the voltage is boosted to, for example, 160 V or 320 V and output, a system interconnection inverter having MPPT control can be used. As a result, the usage efficiency of the solar cell can be improved. Further, even if the conversion means is a variable duty step-up converter circuit and the converter is provided with MPPT control, the utilization efficiency of the solar cell can be similarly increased.
[0025]
Providing the booster circuit in the converter in this manner is preferable because wiring loss to a load such as a system interconnection inverter can be significantly reduced, and a low-cost and highly workable wiring material can be used.
[0026]
In particular, when a converter including a booster circuit is provided on the output side of a low-voltage, large-current solar cell, the effect of reducing wiring loss is extremely large.
[0027]
As the main circuit of the conversion means, various known and commonly used circuit configurations, whether insulated or non-insulated, can be used. Usually, the conversion means has a switching element for switching the input power. The switching element is not particularly limited, but includes, for example, IGBT, MOSFET, bipolar transistor, GTO, IEGT, and the like. When the input voltage is low and the voltage applied to the switching element is low, a MOSFET is suitable.
[0028]
The control circuit of the conversion means includes, for example, a CPU, a PWM waveform control circuit, a maximum power tracking control circuit, a control power generation circuit, a frequency / voltage reference generator, and the like.
[0029]
In the converter according to the present invention, in order to simplify the structure as much as possible and reduce costs and improve reliability, the control circuit includes a control power supply generation circuit, a switching reference waveform generation circuit that defines a switching frequency, and a fixed duty. It is preferable that the driving circuit has at least a driving circuit capable of driving the switching element.
[0030]
Another configuration of the control circuit includes at least a control power generation circuit, a switching reference waveform generation circuit that defines a switching frequency, and a drive circuit that can drive the switching element with a variable duty, and the duty can be adjusted by the maximum power tracking circuit. It is preferable that it is a structure.
[0031]
Still another configuration of the control circuit includes at least a control power generation circuit, a control CPU having a built-in nonvolatile storage unit, a switching reference waveform generation circuit that defines a switching frequency, and a drive circuit that can drive an element. It is preferable that a part or all of the configuration be used also as the control CPU. Further, it is preferable that a part of the communication means is also used as the control CPU.
[0032]
The control power supply circuit is not limited in its configuration. For example, if the control power supply circuit is configured to generate a power supply voltage from electric energy supplied to the input side of the converter, power is supplied from outside the converter, for example, from system power. No need to do. As a result, it is possible to prevent wasteful power consumption during a period in which the conversion device is stopped, such as at night.
[0033]
(Communication means)
The configuration of the communication means used in the conversion device according to the present invention is not particularly limited. For example, as a wireless system, a DC component and / or an AC component such as a magnetic field, an electric field, light, a sound wave, heat, and a mechanical force are used. And more specifically, a wireless tag, an antenna, a photodiode, a microphone, a temperature sensor, and the like. Use of such a means is preferable because communication can be performed without performing wiring connection work, so that workability is high, and reliability is improved in outdoor use.
[0034]
Further, a solar cell connected to the input side of the conversion device can be used as a receiver of the communication means, but in this case, it is not necessary to separately provide a receiver in the communication means, so that miniaturization and cost reduction can be achieved. it can. Further, in a power generation device in which the conversion device and the solar cell are integrally formed, a predetermined signal is transmitted at the time of light irradiation on the solar cell at the time of shipping inspection, so that an initial value is transmitted via the communication means. Information for prohibiting automatic startup in the shipping state can be stored in the storage means. As a result, the manufacturing process can be simplified and the cost can be reduced. In addition, by irradiating the solar cell with light after storing the information prohibiting the automatic activation in the storage means, there is an advantage that it is possible to immediately confirm that the automatic activation of the conversion device is reliably inhibited.
[0035]
On the other hand, as a connection method when using a wired communication means, there are an electric connection by wiring, an optical connection by optical fiber, and the like. The input and / or output wiring of the converter can also be used as a communication line for communication. In this case, it is not necessary to separately connect a communication line, so that workability is improved. In particular, when the outputs of a plurality of converters are connected in parallel, it is possible to communicate with all the converters through the output wiring, and the effect is very large.
[0036]
In the case where the receiver of the communication means has the means for detecting the output voltage of the conversion device, a known and publicly-known voltage detection method can be applied. A / D conversion is performed by dividing the resistance, or the voltage exceeds the Zener voltage. Accordingly, various configurations are possible, such as one in which the light emitting diode conducts and emits light, and the light is received and transmitted by the phototransistor.
[0037]
(Storage means)
The storage means used in the converter according to the present invention is rewritable, and needs to be of a non-volatile type in which stored information is retained even when power is not supplied to the converter. For example, there are a nonvolatile semiconductor memory such as an EEPROM, a flash memory, an SRAM, an MRAM, and an FeRAM having a backup power supply, and a device using a voltage of a capacitor capable of controlling charge / discharge.
[0038]
The use of the nonvolatile semiconductor memory is preferable because a part of the nonvolatile semiconductor memory built in the control CPU of the power control device may be used as the storage means, and the size and cost can be reduced.
[0039]
When a capacitor is used, the capacitor is not particularly limited as long as the voltage can be sufficiently maintained during a period in which power supply to the storage unit is stopped.For example, a multilayer ceramic capacitor, a ceramic capacitor, a metalized polyester film capacitor, a polyester film capacitor, and a polycarbonate film capacitor are used. , Polypropylene film capacitor, electric double layer capacitor, tantalum electric capacitor, aluminum electric capacitor and so on. The means for charging / discharging the capacitor is not particularly limited. For example, a circuit that switches the terminal of the capacitor to a power supply line or a ground line using a transistor or a MOSFET is known.
[0040]
Next, a photovoltaic power generation system according to the present invention will be described in which a solar cell is provided on the input side of the above-described converter and a grid-connected inverter used as a power converter is provided on the output side of the converter.
[0041]
[Solar cells]
Although there is no particular limitation on the solar cell used in the solar power generation system according to the present invention, for example, single-crystal silicon having a pn junction or a pin junction, polycrystalline silicon, microcrystalline silicon, an amorphous silicon semiconductor, or the like can be used. As the compound semiconductor, a group III-V compound, a group II-VI compound, a group I-III-VI compound or the like can be used, and various solar cells can be used. Further, a laminated solar cell constituted by laminating a plurality of these can also be used. Dye-sensitized solar cells and those having other structures are also applicable.
[0042]
[Grid-connected inverter]
The configuration of the grid-connected inverter used in the photovoltaic power generation system according to the present invention is not particularly limited, and various types of publicly known and used configurations can be used. For example, an inverter circuit that converts input power to AC power, automatic start / stop of power conversion, optimization of output from a converter, a control circuit that controls operation modes, a control power supply circuit, a protection circuit, an input / output This device is composed of terminals and the like, and is connected to a commercial AC power system (hereinafter, also simply referred to as a system). If the output voltage of the above-described converter is sufficiently high, it is not necessary for the grid-connected inverter to boost the voltage in the stage preceding the inverter circuit, so that conversion efficiency can be improved and cost can be reduced.
[0043]
Although the configuration of the control power supply circuit of the grid interconnection inverter is not limited, for example, it is preferable to configure the power supply circuit to receive power supply not from the system but from the converter. By doing so, it is possible to prevent useless power consumption while the output from the converter is not performed. In addition, it is preferable to be able to temporarily receive power supply from the commercial AC power system at the time of construction or the like. In this way, even when the power supply from the converter to the grid-connected inverter is stopped, the communication unit of the grid-connected inverter is operated to output a predetermined signal, and the information in the storage unit of the converter described above is output. Can be rewritten all at once.
[0044]
Hereinafter, embodiments of a solar power generation system according to the present invention will be described with reference to the drawings.
[0045]
[Embodiment 1]
As described above, according to one embodiment of the present invention, conversion means for converting input power and outputting the power, and permitting or prohibiting automatic activation of the conversion means when the value of the input voltage exceeds a predetermined threshold value Non-volatile storage means for storing information relating to the control means, control means for controlling activation of the conversion means in accordance with the information stored in the storage means, and automatic activation of the storage means in response to a signal received from outside Or a communication unit for transmitting prohibition information, and configured to rewrite the information stored in the storage unit in accordance with the information transmitted from the communication unit.
[0046]
The first embodiment has the following features in addition to the above.
[0047]
Information for prohibiting automatic activation is stored in the storage means in advance.
[0048]
The communication unit detects that the value of the voltage output from the conversion unit is equal to or higher than the first voltage value, and transmits information for permitting automatic activation.
[0049]
The communication means is configured to receive the signal wirelessly.
[0050]
The storage means is a semiconductor memory.
[0051]
Conversion means boosts the input voltage.
[0052]
The output from the solar cell is input as input power, and the communication unit transmits information for permitting or prohibiting the automatic start to the storage unit according to the value of the voltage output from the solar cell.
[0053]
Also disclosed is a photovoltaic power generation device in which a conversion device having any of the above characteristics and a solar cell that supplies input power to the conversion device are integrally configured. The communication unit transmits information for permitting or prohibiting the automatic activation to the storage unit in response to the optical signal received by at least a part of the solar cell.
[0054]
Furthermore, a plurality of converters having any of the above-mentioned features are provided, and the communication unit of each converter allows or prohibits the storage unit from automatically starting according to a single signal received from the outside. A conversion system for transmitting information is also disclosed.
[0055]
The conversion system has the following features. That is, the output wires of each converter are connected in parallel, and the communication means of each converter receives a single signal through the output wires.
[0056]
FIG. 1 is a schematic diagram illustrating a configuration of a first embodiment of a solar power generation system according to the present invention.
[0057]
The photovoltaic power generation system according to the present embodiment includes a plurality of photovoltaic power generators 1 a to 1 c (hereinafter, collectively denoted by reference numeral 1), a grid interconnection inverter 8, and a commercial AC power grid 9.
[0058]
The photovoltaic power generator 1 includes a solar cell 2, a boost converter 3, an output wire 4, and a connector 5. The output voltage from the solar cell 2 is boosted by the boost converter 3, and the output wire 4 and the connector 5 are connected. Output to outside. Each output of the plurality of photovoltaic power generators 1a, 1b, 1c is connected in parallel by a parallel electric wire 7 via a connector 6, and is input to a grid interconnection inverter 8. The grid interconnection inverter 8 converts the input DC power into AC and outputs the AC power to the commercial AC power system 9.
[0059]
FIG. 2 is a block diagram illustrating a configuration of the solar cell 2 and the boost converter device 3.
[0060]
As illustrated, the solar cell 2 has a configuration in which eight solar cells 11 to 18 are connected in series. In addition, bypass diodes 21 to 28 are connected in parallel to the solar cells 11 to 18 in the opposite direction to the solar cells.
[0061]
The boost converter device 3 includes a smoothing capacitor 31 for smoothing input power, a switching unit 32 for switching its output at a high frequency, a transformer 33 for boosting and electrically insulating, and a rectifying unit 34 for rectifying. Output the boosted DC power. The smoothing capacitor 31 only needs to be able to smooth the high-frequency component by the high-frequency switch of the switching means 32, and may have a small size and a small capacity.
[0062]
The boost converter device 3 includes a control circuit 35, a drive circuit 36, a control power generation circuit 37, a first communication unit 41, a second communication unit 42, and a storage unit 43 as a control system.
[0063]
The control circuit 35 reads the information of the prohibition or permission of the automatic start stored in the storage means 43, and when the automatic start is permitted, if the input power is equal to or more than the predetermined value, the drive circuit 36 outputs the predetermined duty. , A pulse signal having a fixed duty in this embodiment. When the automatic start is prohibited, the pulse signal is not output, and the boost converter device 3 does not perform power conversion. The drive circuit 36 drives each switching element constituting the switching means 32 according to the pulse signal output from the control circuit 35.
[0064]
The control power generation circuit 37 converts the DC power output from the solar cell 2 into power and supplies control power to each circuit in the boost converter device 3.
[0065]
The output voltage of the solar cell 2, the duty of the switching means 32, and the turns ratio of the transformer 33 are set so that the voltage can be increased to a voltage suitable for the operation of the system-linking inverter 8 at the subsequent stage.
[0066]
The first communication unit 41 transmits a signal for permitting automatic activation to the storage unit 43 when a predetermined output voltage fluctuation of the solar cell 2 is detected and exceeds a predetermined threshold.
[0067]
The second communication unit 42 detects a voltage on the output side of the boost converter device 3 and transmits a signal for permitting automatic activation to the storage unit 43 when the voltage exceeds the first voltage. The first voltage is preferably sufficiently larger than zero and about the peak voltage of the commercial AC power system 9 or a voltage lower than the peak voltage. For example, when the commercial AC power system 9 is a single-phase 100V, the first voltage is Set the voltage to 100V.
[0068]
The storage unit 43 stores information of prohibition or permission of automatic start, and in an initial shipment state, the storage unit 43 stores information of prohibition of automatic start. When the automatic start permission signal transmitted from the first communication unit 41 and the second communication unit 42 is received, the stored automatic start information is rewritten to permission. The storage means 43 can be constituted by a nonvolatile semiconductor memory and a circuit for controlling read / write of the nonvolatile semiconductor memory. When the control circuit 35 includes a nonvolatile semiconductor memory or a control CPU with a built-in nonvolatile semiconductor memory, A part may be used as the storage means 43. In addition, all or a part of the first communication unit 41 and the second communication unit 42 may be configured to double as the control CPU of the control circuit 35.
[0069]
FIG. 3 is a block diagram showing a configuration of the grid interconnection inverter 8. As shown in the figure, the system interconnection inverter 8 of the present embodiment includes a smoothing capacitor 81, a switching unit 82, an interconnection reactor 83, an interconnection relay 85, an output current detection unit 84, a control circuit 86, a drive circuit 87, It includes a power supply generation circuit 88, a system voltage detection means 89, an input voltage detection means 90, and an input current detection means 91.
[0070]
The input power is smoothed by a smoothing capacitor 81, converted into AC power by a switching means 82 including a bridge circuit of switching elements, smoothed in waveform through an interconnection reactor 83, and commercial AC power system 9 through an interconnection relay 85. Is output to Note that the smoothing capacitor 81 needs to smooth not only the high-frequency component due to the high-frequency switching by the switching means 82 but also a frequency component as low as twice the commercial AC power frequency output from the grid interconnection inverter 8. A relatively large capacity is required.
[0071]
The output current detecting means 84 detects the output current of the grid interconnection inverter 8 and outputs an output current detection signal to the control circuit 86. Further, the system voltage detecting means 89 detects a system voltage at the output terminal of the system interconnection inverter 8 and outputs a system voltage signal to the control circuit 86. The control circuit 86 performs a so-called system protection function of monitoring the magnitude and frequency of the system voltage from the system voltage signal, and performs a switching signal so that the output current of the system interconnection inverter 8 becomes a sine wave that matches the phase of the system voltage. Is generated and output to the drive circuit 87. The drive circuit 87 drives each switching element of the switching means 82 according to a signal from the control circuit 86.
[0072]
The input voltage detecting means 90 and the input current detecting means 91 detect the input voltage and the input current of the grid interconnection inverter 8, respectively, and output the input voltage signal and the input current signal to the control circuit 86. The control circuit 86 further performs so-called MPPT control for controlling the input power to be maximum using the input voltage signal and the input current signal.
[0073]
The control power generation circuit 88 converts the DC power from the boost converter device 3 into power and supplies control power to each circuit in the system interconnection inverter 8. That is, in the system interconnection inverter 8 of the present embodiment, the control circuit operates by the power supply from the boost converter device 3, checks the status of input / output, and automatically starts the power conversion operation if operable.
[0074]
FIG. 4 is a block diagram illustrating a configuration of the first communication unit 41. As illustrated, the first communication unit of the present embodiment includes an input voltage detection unit 51 for detecting an output voltage of the solar cell 2, and a predetermined center frequency f 1 based on an input voltage signal output from the input voltage detection unit 51. A band-pass filter BPF 52 for extracting an AC component, a band-pass filter BPF 53 for extracting an AC component having a predetermined center frequency f2 from an input voltage signal output from the input voltage detecting means 51, and two band filters extracted from the BPF 52 and the BPF 53 A determination unit 54 determines whether each signal level is higher than a predetermined signal level.
[0075]
The judging means 54 outputs a signal for prohibiting automatic activation when the signal of the f1 component extracted by the BPF 52 is higher than a predetermined level, and outputs a signal for prohibiting the automatic activation when the signal of the f2 component extracted by the BPF 53 is higher than the predetermined level. Outputs a signal that permits automatic startup. Then, the information of the automatic activation of the storage means 43 is rewritten by these signals.
[0076]
FIG. 5 is a block diagram showing a configuration of the second communication unit 42. As shown in the figure, the second communication means of the present embodiment includes an output voltage detection means 61 for detecting an output voltage of the boost converter device 3, and whether an output voltage signal from the output voltage detection means 61 is higher than the first voltage. A voltage determination means 62 for determining whether the output voltage signal is higher than the first voltage, and a timer means 63 for outputting a signal for permitting the automatic start when the determination signal continues for a predetermined time.
[0077]
With this configuration, a signal that prohibits automatic activation is transmitted from the first communication unit 41 by irradiating the solar cell 2 with light having a light amount fluctuation of the frequency f1 during the shipping inspection of the photovoltaic power generator 1. Then, the information of the prohibition of the automatic activation is written and stored in the storage means 43. As a result, the control circuit 35 detects that the information of the automatic start is prohibited, does not start the conversion operation even if the input power exceeds the predetermined value, and disables the solar power generation device 1 from solar radiation during the installation work. Easy output of power can be prevented.
[0078]
Also, by irradiating the solar cell 2 with light having a light quantity fluctuation of the frequency f2 when the installation work is completed, a signal to permit automatic start is transmitted from the first communication means 41 and the automatic start is stored in the storage means 43. Is written and stored. Thereby, the control circuit 35 detects that the information of the automatic activation is permitted, automatically activates the conversion operation when the input exceeds a predetermined value, and outputs the electric power from the photovoltaic power generator 1 after the predetermined installation work. .
[0079]
Further, when one solar power generation device 1 starts power generation, the output terminals are connected in parallel, so that the voltage of each output terminal of the other solar power generation devices 1 also increases. Then, in each of the other photovoltaic power generators 1, when each output voltage exceeds the first voltage, a signal for permitting automatic start is transmitted from the second communication means 41, and the permission of automatic start is transmitted to the storage means 43. Information is written and stored. As a result, the control circuit 35 detects that the information of the automatic start is permitted, automatically starts the power conversion operation, and the other solar power generation devices 1 also start outputting power.
[0080]
As described above, by giving the light amount fluctuation of the frequency f2 to the solar cell 2 of one photovoltaic power generation device 1, the permission of the automatic start is written in the storage means 43 of the other photovoltaic power generation device 1. The work of changing the information of automatic start of the photovoltaic power generator 1 to permission is simplified, and workability is remarkably improved. Further, since the output voltage from the boost converter device 3 can be used to transmit the signal for permitting the automatic start from the photovoltaic power generation device 1, it is not necessary to separately provide a signal transmission unit in the communication unit. It can be simple, small, and inexpensive.
[0081]
In addition, when the solar cell and the converter device are connected by a connector or the like, once the information of permission for automatic activation is written in the storage means, the connection between the solar cell and the converter device is once disconnected, and the solar cell is connected to the converter device. When the output of the converter device is checked again after checking the output, the converter device is automatically started without giving a start signal again as in the conventional case, so that the workability is improved.
[0082]
Furthermore, since the control power of the grid-connected inverter 8 is supplied from the photovoltaic power generator 1, the control power is supplied only when the power can be generated by the photovoltaic power generator. There is no consumption.
[0083]
Note that it is necessary that the two components of the frequencies f1 and f2 can be reliably separated, and in the case of the above-described configuration, it is preferable that one of the components is at least twice the other. Further, the frequencies f1 and f2 need to be set in consideration of the frequency characteristics of the solar cell 2 and the first communication means, and are preferably selected from a range of several Hz to several hundred kHz. However, it is preferable that the switching frequency does not overlap with the switching frequency of the switching means 32 or its higher harmonic, and in the case of overlapping, the setting of the detection level should be considered.
[0084]
It should be noted that the light having the light quantity fluctuation of the frequency f1 and / or f2 may be applied to all or some of the solar cells of the solar cell 2. As a method of generating light having a light quantity fluctuation, there are a method using a light emitting means having a light quantity fluctuation, and a method of changing a light quantity reaching a solar battery cell by blocking steady light by reflection or absorption. Further, the light amount of the light having the light amount fluctuation may be substantially zero when the light amount is minimal, or may have a predetermined level without the light amount being zero. These can be used in appropriate combination. Specifically, a method of using pulse emission of a predetermined frequency of a measuring device for measuring the output characteristics of the solar cell, a method of controlling the amount of light transmitted to the solar cell by a liquid crystal shutter, or the like can be used.
[0085]
[Embodiment 2]
Next, a second embodiment of the photovoltaic power generation system according to the present invention will be described. In the following, portions that are the same as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0086]
The second embodiment stores conversion means for converting and outputting input power and information on whether to automatically permit or prohibit automatic activation of the conversion means when the value of the input voltage exceeds a predetermined threshold value. Non-volatile storage means, control means for controlling the activation of the conversion means in accordance with the information stored in the storage means, and information for permitting or prohibiting the automatic activation of the storage means in response to a signal received from outside. And a communication unit for transmitting, wherein the output from the solar cell having a plurality of cells is the input power, in a converter configured to rewrite the information stored in the storage unit in accordance with the information transmitted from the communication unit. The communication means transmits information for permitting or prohibiting the automatic start to the storage means according to a voltage value output from at least one cell of the solar cell. The case, the present embodiment, the conversion system having a plurality of said conversion device, photovoltaic device, and in which also discloses a power conversion system.
[0087]
FIG. 6 is a block diagram illustrating a configuration of the solar cell 2 and the boost converter device 3 of the photovoltaic power generation system according to the present embodiment. The only difference from the configuration shown in FIG. 2 relating to the first embodiment is a portion relating to signal detection of the first communication means of the boost converter 3, and this portion will be described.
[0088]
In the first embodiment, the first communication means 41 detects an output voltage fluctuation at both ends of the solar cell 2 (one in which the solar cells 11 to 18 are connected in series) and automatically activates when the output voltage fluctuation exceeds a predetermined threshold. Is transmitted to the storage unit 43, but the first communication unit 41 of the present embodiment detects a voltage change between both ends of the solar cell 18 in the solar cell 2 and performs a predetermined operation. When the threshold value is exceeded, a signal for permitting automatic activation is transmitted to the storage unit 43.
[0089]
Therefore, according to the present embodiment, by irradiating only the photovoltaic cells 18 with light having a light amount variation, the first communication means 41 transmits a signal for prohibiting or permitting the automatic activation, and the storage means 43 You can rewrite the information of the automatic start of. In addition, since light having a light amount variation only needs to be irradiated to one solar cell 18, light irradiation becomes easy. In addition, since only the voltage between both ends of one solar cell 18 needs to be detected, the S / N ratio at the time of detection is improved and the detection accuracy is increased. Furthermore, if the other solar cell is irradiated with a certain amount of light while irradiating the solar cell 18 with light having a light amount fluctuation, the power supplied from the control power supply is also stabilized. Can be expected.
[0090]
Furthermore, the output of each of a plurality of solar cells instead of one solar cell may be detected to detect the power generation state of the plurality of solar cells. By doing so, it is possible to transmit complicated information and to improve the reliability of information transmission.
[0091]
[Embodiment 3]
Next, a third embodiment of the photovoltaic power generation system according to the present invention will be described. In the following, portions similar to those of the first and second embodiments are denoted by the same reference numerals, description thereof will be omitted, and description will be made focusing on characteristic portions of the present embodiment.
[0092]
The third embodiment stores conversion means for converting and outputting input power and information on whether to allow or prohibit automatic activation of the conversion means when the value of the input voltage exceeds a predetermined threshold value. Non-volatile storage means, control means for controlling the activation of the conversion means in accordance with the information stored in the storage means, and information for permitting or prohibiting the automatic activation of the storage means in response to a signal received from outside. A converter configured to rewrite information stored in the storage unit in accordance with the information transmitted from the communication unit, and a solar cell that supplies input power to the converter. In the photovoltaic power generation device characterized in that the communication means is provided in a region other than the light receiving surface of the solar cell, the present embodiment has a plurality of the conversion devices. You Conversion system, and in which also discloses a power conversion system.
[0093]
FIG. 7 is a diagram illustrating an appearance of the solar power generation device 1 according to the present embodiment. The difference from FIG. 1 shown in the first embodiment is that the antenna coil 44 is provided on the upper part of the photovoltaic power generator 1. That is, in the solar power generation device 1 of the present embodiment, the antenna coil 44 is provided in a region other than the light receiving surface of the solar cell 2 and outside the housing of the boost converter device 3.
[0094]
FIG. 8 is a block diagram illustrating a configuration of the solar power generation device 1 according to the present embodiment. As shown in the drawing, unlike the first embodiment, an antenna coil 44 and a wireless receiving unit 45 are provided instead of the first communication unit 41. The antenna coil 44 receives an electromagnetic wave excited from the outside and outputs it to the wireless receiving unit 45. The wireless receiving unit 45 performs predetermined signal processing on the input signal to extract information. When the signal for prohibiting or permitting the automatic activation is extracted, the wireless receiving unit 45 rewrites and stores the information on the prohibition or the permission of the automatic activation in the storage unit 43.
[0095]
As described above, by transmitting a signal for prohibiting or permitting automatic activation from the outside by means of an electromagnetic wave, information on the automatic activation of the storage means 43 is simultaneously rewritten to prohibition or permission within a range in which radio waves can be received with a predetermined intensity. Since it is not necessary to rewrite the storage means 43 of each photovoltaic power generator 1, workability at the time of installation is improved. In addition, according to the present embodiment, the control range for the storage unit 43 can be adjusted by adjusting the signal intensity of the electromagnetic wave, and for example, the storage of the solar power generation device 1 in close proximity can be adjusted by weakening the signal intensity of the electromagnetic wave. Only the means 43 can be controlled to rewrite the information of automatic activation.
[0096]
Even in this case, when one of the solar power generation devices 1 starts power generation, the information of automatic activation of the storage means 43 of the other solar power generation devices 1 whose output terminals are connected in parallel by the second communication means is simultaneously transmitted. Since it is rewritten, the installation workability is improved.
[0097]
[Embodiment 4]
Next, a fourth embodiment of the photovoltaic power generation system according to the present invention will be described. In the following, the same parts as those in the first to third embodiments are denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on the characteristic parts of the present embodiment.
[0098]
In the present embodiment, the basic configuration of the photovoltaic power generator 1 is the same as that shown in FIG.
[0099]
That is, the storage unit of the present embodiment permits the capacitor, the switch unit that changes the state of charge of the capacitor according to the information transmitted from the communication unit, and the automatic start according to the value of the voltage charged in the capacitor. Determination means for determining whether to perform or prohibit.
[0100]
Hereinafter, the storage unit of the present embodiment will be described with reference to FIG.
[0101]
The storage unit 43 of the present embodiment includes a capacitor 101 that stores information of automatic activation as a voltage, a charge switch 102 that charges the capacitor 101, a discharge switch 103 that discharges the capacitor 101, and a charge voltage of the capacitor 101. A voltage judging means for judging whether the information of the automatic start is prohibited or permitted based on the value; outputting the information of the automatic start to the control circuit in response to the judgment signal from the voltage judging means; 41 and a storage control means 105 for switching the start information as needed based on the signal of prohibition or permission of automatic start received from the second communication means 42. The information on the automatic activation output from the storage control unit 105 is also used as a control signal for the charge switch 102 and the discharge switch 103.
[0102]
The voltage determination unit 104 of the present embodiment determines that the automatic start is permitted when the value of the voltage charged in the capacitor 101 is higher than a predetermined threshold, and prohibits the automatic start when the value of the voltage charged is lower than the predetermined threshold, and outputs a corresponding determination signal. .
[0103]
During a normal operation, the storage control means 105 outputs information of prohibition or permission of automatic start according to the determination signal output from the voltage determination means 104. The charging switch 102 charges the capacitor 101 when the information of the automatic activation is permitted, and does not perform the charging when the information of the automatic activation is prohibited. On the other hand, the discharge switch 103 discharges the capacitor 101 when the information of the automatic activation is prohibited, and does not perform the discharge when the information of the automatic activation is permitted. The charge switch 102 and the discharge switch 103 do not perform the charging operation and the discharging operation at the same time, but operate complementarily. As described above, normally, the information of the automatic start according to the charge voltage of the capacitor 101 is output to the control circuit 35, and the charge state of the capacitor 101 is maintained by the charge switch 102 and the discharge switch 103, and the stored automatic state is stored. Startup information is retained.
[0104]
When a signal for prohibiting or permitting automatic activation is input from the first communication unit 41 or the second communication unit 42, the storage control unit 105 gives priority to the determination signal from the voltage determination unit 104 and The information of the prohibition or permission of the automatic start according to the signal of the automatic start is output. In other words, if the judgment signal and the signal of the automatic activation from the communication means are different (the judgment means is permitted and the communication means is prohibited, or the judgment means is prohibited and the communication means is permitted), the automatic activation signal transmitted from the communication means is transmitted. The storage control unit 150 changes the states of the charge switch 102 and the discharge switch 103 according to the information, and changes the value of the charge voltage of the capacitor 101.
[0105]
In response to this, the determination signal output from the voltage determination unit 104 also changes from permission to prohibition or from prohibition to permission. As a result, the determination signal output to the storage control circuit 105 matches the automatic start signal transmitted from the communication unit. The storage control circuit 105 retains the information of the automatic activation of the changed prohibition or permission even after the transmission of the automatic activation signal from the communication unit is stopped. As described above, the stored automatic activation information is rewritten according to the signal transmitted from the first communication unit 41 or the second communication unit 42 to prohibit or permit the automatic activation.
[0106]
Also, no control power is generated because the solar cell 2 cannot generate power at night, but the charge switch 102, the discharge switch 103, and the voltage determination means 104 are controlled so that the charged state of the capacitor 101 can be maintained even when there is no control power. It is desirable to configure the terminal connected to the capacitor 101 to have sufficiently high impedance. Specifically, it is sufficient that the charged state can be maintained for at least about one day in a state where the control power is not generated. When the solar cell 2 stops generating power, the control power is lost and the charging voltage of the capacitor gradually decreases. In the next morning, when the solar battery 2 generates power again to generate the control power, the capacitor 101 is charged again and the charged state is maintained, so that the solar power generation device 1 can perform the same operation as the previous day.
[0107]
Further, since the configuration is such that the automatic activation is prohibited when the value of the charging voltage is low, the prohibition state can be reliably maintained even if a long time has passed since shipment. Also, if it is known that the time during which the charged state of the capacitor cannot be maintained during the period from shipping inspection to installation, it will automatically start automatically without writing the information of auto start at the time of shipment. Information is set to prohibited.
[0108]
As described above, according to the present embodiment, a nonvolatile semiconductor memory and a control CPU are not required, and a simple and inexpensive storage unit can be realized. In addition, when generating a pulse of a fixed frequency or a pulse of a fixed duty, for example, the configuration of the control circuit 35 can be configured with simple hardware. Therefore, a control CPU is not required, and the configuration of the boost converter device 3 is reduced. Simple and inexpensive construction. Further, in this case, it is easy to integrate the entire boost converter 3 into a dedicated IC.
[0109]
[Embodiment 5]
Next, a fifth embodiment of the photovoltaic power generation system according to the present invention will be described. In the following, the same parts as those in the first to fourth embodiments are denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on the characteristic parts of the present embodiment.
[0110]
The fifth embodiment stores conversion means for converting and outputting input power, and information on whether to allow or prohibit automatic activation of the conversion means when the value of the input voltage exceeds a predetermined threshold. Non-volatile storage means, control means for controlling the activation of the conversion means in accordance with the information stored in the storage means, and information for permitting or prohibiting the automatic activation of the storage means in response to a signal received from outside. Communication means for transmitting, and a plurality of converters configured to rewrite the information stored in the storage means in accordance with the information transmitted from the communication means, wherein the communication means of each conversion apparatus is an external device. A conversion system for transmitting information for permitting or prohibiting the automatic activation to the storage means in response to a single signal received from a power supply, and converting the power output from each conversion device into AC power to convert the power into AC power. A power conversion system comprising: a grid-connected inverter that outputs power to the grid-connected inverter, wherein a power supply circuit for controlling the grid-connected inverter is supplied with power from a plurality of converters, and a single signal is output from the grid-connected inverter. The system interconnection inverter discloses a power conversion system configured to be supplied with power from a commercial AC power system when outputting a single signal.
[0111]
The configuration of the photovoltaic power generation system as the power conversion system of the present embodiment is substantially the same as that of the first embodiment, but the configuration of the system interconnection inverter 8 is different.
[0112]
FIG. 10 is a block diagram showing a configuration of the grid interconnection inverter 8 of the present embodiment. The same parts as those in FIG. 3 shown in the first embodiment are denoted by the same reference numerals. The system interconnection inverter 8 of the present embodiment differs from the system interconnection inverter of the first embodiment in that the system interconnection inverter 8 includes a switch 111 and a current limiting resistor 112 that can be operated from the outside. The switch 111 and the resistor 112 are connected in series, and both ends are connected to the input / output terminal of the interconnection relay 85, respectively.
[0113]
In the present embodiment, consider a case where the automatic startup of the boost converter device 3 is prohibited. Since the automatic start-up of the boost converter device 3 is prohibited, the output is stopped, and the voltage at the input terminal of the grid interconnection inverter 8 is approximately zero.
[0114]
Here, the switch 111 is turned on by operating the switch 111. Thereby, the interconnection reactor 83 is connected to the commercial AC power supply system 9 via the switch 111 and the resistor 112 in the ON state. The voltage of the commercial AC power supply system 9 is applied to the switching means 82 via the switch 111, the resistor 112, and the interconnection reactor 83. Since the switching means 82 has switching elements bridge-connected, the applied voltage of the commercial AC power supply system 9 is rectified by the switching means 82, and the current limited by the resistor 112 charges the smoothing capacitor 81. When the ON state of the switch 111 is continued until the smoothing capacitor 81 is sufficiently charged, the smoothing capacitor 81 is charged to approximately the peak value of the system voltage of the commercial AC power supply system 9.
[0115]
The voltage charged in the smoothing capacitor 81 in this way is also transmitted to the output terminal of each boost converter device 3. For example, if the commercial AC power supply system is a single-phase 100V and the first voltage of the second communication means 42 of the boost converter device 3 is set to 100V, the communication device 42 causes the voltage on the output side of the boost converter device 3 to become the second voltage. It is detected that the voltage exceeds one voltage, and a signal for permitting the automatic start is output to the storage unit 43.
[0116]
As described above, according to the present embodiment, a signal for permitting automatic activation is transmitted from the grid interconnection inverter 9 to each boost converter device 3, and the automatic activation information in the storage unit 43 of each boost converter device 3 is rewritten. Therefore, workability is improved. Further, by using the switching means 82 also as a rectifying element as described above, the voltage of the first voltage can be easily sent to the second communication means 42 of the boosting converter device 3, so that the boosting converter device 3 can be reduced in size and size. It can be realized at a low price. Further, the grid-connected inverter 9 normally operates by generating a control power supply from the input side and is configured to supply power from the commercial AC grid 9 only when transmitting a signal for permitting automatic start-up. There is no need to supply power from the commercial AC system 9 while the solar cell 2 is not generating power, and wasteful power consumption can be prevented.
[0117]
In the present embodiment, the signal for permitting automatic start is generated by rectifying the signal from the commercial AC system 9 via the resistor by the switching means 82. However, the present invention is not limited to this. Various configurations are conceivable, such as a power supply path from the input to the input side, a location where a resistor is provided, and the presence or absence thereof.
[0118]
<Modification>
In addition, the output voltage of each boost converter 3 when disconnected from the grid-connected inverter 8 is set as a second voltage, and the grid-connected inverter 8 automatically starts a third voltage higher than the second voltage. The second communication means detects that the output voltage of each boost converter device 3 is equal to or higher than the third voltage, and rewrites the information of the automatic start of the storage means 43 to be prohibited. It may be configured as follows. In this case, the outputs of the step-up converter devices 3 can be stopped at the same time from the system interconnection inverter 8, and for example, the simultaneous stop at the time of maintenance can be easily coped with, and the workability is improved.
[0119]
Even when the system interconnection inverter 8 is not connected, the information of the automatic storage of the storage unit 43 is prohibited when the first communication unit 41 of any boost converter device 3 receives a signal for prohibiting the automatic start. And may be configured to be temporarily operable up to a third voltage higher than the second voltage. Also in this case, since the third voltage is applied to the output side of the other boost converter device 3 and the output of the other boost converter device 3 can be stopped all at once, it is easy to cope with the simultaneous stop during maintenance. Workability is improved.
[0120]
<Other embodiments>
The present invention can be applied to a system including a plurality of devices (for example, a conversion system, a power conversion system, a photovoltaic power generation system, etc.), but also to a device including one device (for example, a boost converter device). Conversion device, solar power generation device, etc.).
[0121]
Further, an object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and a computer (or CPU or MPU) of the system or apparatus to store the storage medium. It is needless to say that the present invention can also be achieved by reading and executing the program code stored in the program.
[0122]
In this case, the program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
[0123]
As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, and the like can be used.
[0124]
When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also an OS (Operating System) running on the computer based on the instruction of the program code. It goes without saying that a part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0125]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that a CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.
[0126]
【The invention's effect】
As described above, according to the present invention, for example, in a configuration in which a solar cell or the like is used as an input, it is possible to prevent the solar cell from generating power at the time of construction and the like, and to prevent the converter from being automatically activated. Later, control can be performed so that the conversion device is automatically activated. In addition, for example, the communication unit can transmit information for permitting or prohibiting the automatic activation to the storage unit in response to a signal received via a solar cell or the like as an input unit, so that wasteful power is consumed. Consumption can be reduced.
[0127]
Therefore, it is possible to control the activation state of the conversion device even at the time of construction, and to reduce unnecessary power consumption.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration of a first embodiment of a solar power generation system according to the present invention.
FIG. 2 is a block diagram showing a configuration of a solar cell and a boost converter of FIG.
FIG. 3 is a block diagram illustrating a configuration of a system interconnection inverter of FIG. 1;
FIG. 4 is a block diagram illustrating a configuration of a first communication unit in FIG. 2;
FIG. 5 is a block diagram illustrating a configuration of a second communication unit in FIG. 2;
FIG. 6 is a block diagram illustrating a configuration of a solar cell and a boost converter according to a second embodiment of the solar power generation system.
FIG. 7 is a diagram illustrating an appearance of a solar power generation device according to a third embodiment of the solar power generation system.
8 is a block diagram showing a configuration of a solar cell and a boost converter of the solar power generation device of FIG.
FIG. 9 is a block diagram illustrating a configuration of a storage unit according to a fourth embodiment of the solar power generation system.
FIG. 10 is a block diagram illustrating a configuration of a grid-connected inverter according to a fifth embodiment of the photovoltaic power generation system.
[Explanation of symbols]
1 Photovoltaic power generator
2 solar cells
3 Boost converter device
4 Output wire
5 Connector
6 Connector
7 Parallel wires
8 Grid-connected inverter
9 Commercial AC system
11-18 solar cells
21-28 Bypass diode
31 Smoothing capacitor
32 Switching means
33 transformer
34 rectification means
35 control circuit
36 Drive circuit
37 Control power generation circuit
41 first communication means
42 second communication means
43 storage means
44 antenna
45 Wireless receiver
51 Input voltage detecting means
52, 53 BPF
54 Judging means
61 Output voltage detection means
62 Voltage judgment means
63 Timekeeping means
81 Smoothing capacitor
82 Switching means
83 interconnection reactor
84 Output current detecting means
85 interconnection relay
86 control circuit
87 drive circuit
88 Control power generation circuit
89 System voltage detection circuit
90 Input voltage detection circuit
91 Input current detection circuit
101 Capacitor
102 Charge switch
103 Discharge switch
104 Voltage judgment means
105 storage control means
111 switch
112 resistance

Claims (1)

Conversion means for converting and outputting input power;
When the value of the input voltage exceeds a predetermined threshold, non-volatile storage means for storing information on whether to allow or prohibit automatic activation of the conversion means,
Control means for controlling activation of the conversion means according to the information stored in the storage means;
Communication means for transmitting information for permitting or prohibiting the automatic activation to the storage means in response to a signal received from outside,
A conversion device configured to rewrite information stored in the storage unit according to information transmitted from the communication unit.

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