JP7148244B2 - Power controllers, photovoltaic systems, and programs - Google Patents

Description

The present invention relates to a power control device capable of suppressing a decrease in power generation efficiency of a solar cell module in a photovoltaic power generation system, a photovoltaic power generation system including the power control device, and a program.

In a solar cell module, a phenomenon called PID (Potential Induced Degradation) is known, in which the power generation efficiency of the module decreases with the passage of power generation time. Techniques for suppressing PID are also known. For example, Patent Documents 1 and 2 disclose a power control device capable of suppressing a decrease in power generation efficiency by preventing a power generation section in a back electrode type solar cell module from being in a state higher in potential than the ground potential. and a photovoltaic system are disclosed.

Japanese Patent Application Laid-Open No. 2015-56117 (published on March 23, 2015) Japanese Patent Application Laid-Open No. 2015-56118 (published on March 23, 2015)

However, both Patent Documents 1 and 2 are intended for back electrode type solar cell modules, and their configurations cannot be applied to conventional double-sided electrode type solar cell modules. Furthermore, Patent Documents 1 and 2 do not assume a photovoltaic power generation system equipped with a power storage device that stores power generated by a solar cell module or purchased power purchased from a power grid and discharges it as needed. I had a problem.

In order to solve the above-described problems, a power control device according to an aspect of the present invention includes a double-sided electrode type solar cell module whose frame is grounded, a power storage device that stores and discharges power, and an external grid power network. a power control device for controlling input and output of power in a photovoltaic power generation system connected to and including the photovoltaic module, wherein the power storage device performs either storage or discharge with the grid power network, In addition, when the electromotive voltage in the solar cell module is lower than a predetermined voltage, a control signal is generated for disconnecting the solar cell module.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, there is an effect that it is possible to provide a power control device capable of suppressing a decrease in power generation efficiency of a solar cell module.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows an example of a principal part structure of the photovoltaic power generation system which concerns on Embodiment 1 of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the external appearance of the solar cell module used with the said solar power generation system, (a) is the front view seen from the light-receiving surface side, (b) is the figure seen transparently from the back surface. 2 is a cross-sectional view of a solar cell module used in the solar power generation system; FIG. FIG. 4 is a schematic diagram estimating the cause of a decrease in power generation efficiency in the solar cell module shown in FIG. 3; It is a schematic diagram which shows the structural example of the circuit of the said electric power control apparatus. FIG. 5 is a schematic diagram showing a configuration example of a circuit of a power control device according to Embodiment 2 of the present invention;

[Embodiment 1]
An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 5. FIG.

(Configuration of photovoltaic power generation system)
A configuration of a photovoltaic power generation system 1 according to this embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing an example of the main configuration of a photovoltaic power generation system 1. As shown in FIG.

The solar power generation system 1 includes a solar cell module 10, a power storage device 20, and a power control device 30. The solar cell module 10 and the power storage device 20 are connected to the grid power network 2 via the power control device 30. .

The photovoltaic power generation system 1 can convert the power generated by the double-sided electrode type solar cell module 10 whose frame is grounded by the power control device 30 and output it to the power storage device 20 and the grid power network 2 . The photovoltaic power generation system 1 is configured to be connectable to an external grid power network 2 , and can purchase (purchase) power from the grid power grid 2 and store it in the power storage device 20 . Furthermore, the photovoltaic power generation system 1 can cut off the connection between the photovoltaic module 10 and the power control device 30 when the photovoltaic module 10 is not generating power effectively.

The grid power network 2 is an external power network managed and operated by a power company. The photovoltaic power generation system 1 can purchase (purchase) power from a power company or sell (sell) power to the power company via the grid power network 2 . In the illustrated example, the grid power network 2 is a single-phase three-wire power supply grounded at the midpoint. In the following description, it is assumed that the power supplies on the upper and lower sides of the figure are AC 100V power supplies, respectively, and AC 200V is connected to power control device 30 .

The solar cell module 10 is a commonly used double-sided electrode type solar cell module. output from the electrodes. Moreover, the solar cell module 10 is supported by a grounded frame (outer frame). In the illustrated example, of the two lines connecting the solar cell module 10 and the power control device 30, the upper side with the subscript P indicates the output on the positive electrode side, and the lower side with the subscript N indicates the negative electrode side output. shows the output. In addition, the solar cell module 10 may be configured by one module, or may be configured by connecting a plurality of modules. A specific configuration of the solar cell module 10 will be described later.

The power storage device 20 can store and discharge power. Specifically, the power storage device 20 can store power generated by the solar cell module 10 or purchased power purchased from the power company via the grid power network 2 via the power control device 30 . In addition, the power storage device 20 can discharge the power stored in itself to drive an electrical device (not shown), or can reversely flow the power to the grid power network 2 and sell (sell) the power.

The power control device 30 is connected to the solar cell module 10 , the power storage device 20 , and the grid power network 2 , and controls power input/output in the photovoltaic power generation system 1 . The power control device 30 has a positive input terminal 131 for inputting the positive side of the output voltage of the solar cell module 10 and a negative input terminal 132 for inputting the negative side thereof.

Power control device 30 includes booster circuit 101 , bidirectional PWM inverter 102 , AC reactor 103 , bidirectional DC/DC converter 104 , relay 105 , and switching control section 107 .

Booster circuit 101 is arranged between solar cell module 10 and bidirectional PWM inverter 102 and boosts the voltage to the negative electrode side of solar cell module 10 . The booster circuit 101 may have a known circuit configuration using a coil, a diode, and a FET (Field-Effect Transistor) functioning as a switching power element for controlling the boost ratio.

Bidirectional PWM inverter 102 is connected to booster circuit 101 , AC reactor 103 , and bidirectional DC/DC converter 104 . The bidirectional PWM inverter 102 controls the voltage so that the DC power generated by the solar cell module 10 and the power storage device 20 are discharged, and the DC power converted by the bidirectional DC/DC converter described later is converted into AC power. It can be converted and reverse power flowed to the grid power network 2 . In addition, bidirectional PWM inverter 102 controls voltage to convert AC power purchased from a power company through system power network 2 into DC power, and outputs the DC power to booster circuit 101 or bidirectional DC/DC converter 104 . can do.

The AC reactor 103 is arranged between the bidirectional PWM inverter 102 and the system power network 2 , suppresses harmonics in the AC power input from the system power network 2 , and can output the AC power to the bidirectional PWM inverter 102 . .

Bidirectional DC/DC converter 104 is arranged between power storage device 20 , booster circuit 101 and bidirectional PWM inverter 102 . Bidirectional DC/DC converter 104 operates by switching between two operation modes: a step-down mode in which power is stored in power storage device 20 and a step-up mode in which power is discharged to power storage device 20 . Here, in the step-down mode, at least one of the DC power generated by the solar cell module 10 and the DC power converted from the AC power by the bidirectional PWM inverter 102 is modulated so that the power storage device 20 can store the power. This mode performs processing such as On the other hand, the boost mode is a mode in which processing such as modulation is performed so that the DC power discharged to the power storage device 20 can be converted into AC power by the bidirectional PWM inverter 102 .

The relay 105 is a switch that is arranged between the solar cell module 10 and the booster circuit 101 and can be turned on and off. The relay 105 can switch between connection and non-connection with the solar cell module 10 based on the control signal received from the switching control unit 107 . The relay 105 disconnects the solar cell module 10 when the solar cell module 10 is not generating power and the power storage device 20 is either storing or discharging power with the grid power network 2 . It is preferable that the configuration is such that it is possible to

The switching control unit 107 is a controller that generates control signals for controlling each unit of the power control device 30 . Specifically, switching control unit 107 controls the operations of booster circuit 101, bidirectional PWM inverter 102, bidirectional DC/DC converter 104, and relay 105 using control signals. Switching control unit 107 can switch between power storage and discharge in power storage device 20 by switching the operation mode of bidirectional PWM inverter 102 and bidirectional DC/DC converter 104 according to a control signal. When power storage device 20 is performing either storage or discharge with system power grid 2 and the electromotive voltage in solar cell module 10 is lower than a predetermined voltage, switching control unit 107 switches between solar cell module 10 and A control signal can be generated to disconnect from the power controller 30 .

(Configuration example of a solar cell module)
A configuration example of the solar cell module 10 according to the present embodiment will be described with reference to FIGS. 2 to 4. FIG. 2A and 2B are schematic views showing the appearance of the solar cell module 10 used in the photovoltaic power generation system 1. FIG. 2A is a front view seen from the light receiving surface side, and FIG. It is a diagram.

(a) of FIG. 2 shows a front view of the solar cell module 10 . The solar cell module 10 is composed of a plurality of solar cells 13 surrounded by a frame. The plurality of photovoltaic cells 13 are arranged in a matrix, and each photovoltaic cell 13 has a first electrode provided on the back surface side of the light receiving surface thereof, which is provided on the light receiving surface side of another photovoltaic cell 13 . is connected to the second electrode. Thereby, all the solar cells 13 included in the solar cell module 10 are connected in series.

FIG. 2(b) shows the appearance of the solar cell module 10 on the back side. The ends of the plurality of photovoltaic cells 13 connected in series are led to a terminal box provided on the back side by another wiring. A terminal on the positive electrode side and a terminal on the negative electrode side of the output voltage are provided as the output terminals 17 in the terminal box. Through these terminals, electric power generated by the plurality of solar cells 13 connected in series can be output to the outside. In addition, when the solar cell 13 is manufactured using a p-type silicon substrate, the first electrode is a positive electrode and the second electrode is a negative electrode. On the other hand, when the solar cell 13 is manufactured using an n-type silicon substrate, the configuration is reversed.

FIG. 3 is a cross-sectional view of the solar cell module 10. FIG. In the illustrated example, the two solar cells 13 have one positive electrode connected to the other negative electrode by an inner connector 16 . Moreover, the right solar cell 13 is connected to the first electrode bus bar 14a and the second electrode bus bar 14b by another inner connector 16 connected to the back side. Photovoltaic cell 13 is fixed between cover glass 19 and back surface protective sheet 15 by first sealing resin 11a and second sealing resin 11b. In addition, an antireflection film (not shown) may be arranged between the second sealing resin 11b and the solar cell 13 .

Light incident from the light receiving surface reaches solar cell 13 via cover glass 19, first sealing resin 11a, second sealing resin 11b, and an antireflection film (not shown). As a result of generating holes and free electrons in the solar cell 13 by the photoelectric effect, a voltage is generated between the electrodes. The solar cell module 10 synthesizes the voltages generated in the plurality of solar cells 13 and outputs it to the outside as the electromotive voltage of the solar cell module 10 .

(Presumption of PID Occurrence Cause in Double-Sided Electrode Type Solar Cell Module)
As described with reference to FIG. 3 , the solar cell module 10 is configured such that the light incident from the light receiving surface passes through a plurality of members before reaching the solar cell 13 . Based on this, the inventors speculated the cause of PID in the double-sided electrode type solar cell module including the solar cell module 10 according to the present embodiment as follows. The estimated contents will be described below with reference to FIG. FIG. 4 is a schematic diagram presuming the cause of the decrease in power generation efficiency in the solar cell module shown in FIG. The solar cell module 10 is supported by a grounded frame 18, and the frame 18 and the cover glass 19 are in contact with each other. In the following description, the solar cell 13 is manufactured using a p-type silicon substrate, the first electrode 12a provided on the back surface side is the positive electrode, and the first electrode 12a provided on the light receiving surface side is the positive electrode. It is assumed that the second electrode 12b is the negative electrode.

When the solar cell module 10 generates power, the second electrode 12b provided on the light receiving surface side operates as a negative electrode. As a result, an electric field is generated between the cover glass 19 in contact with the frame 18 and the second electrode 12b. In other words, the potential of the cover glass 19 in contact with the grounded frame 18 becomes higher than the potential of the second electrode 12b. At this time, for example, if the cover glass 19 contains cations (Na ⁺ in the figure), the cations move according to the electric field. Specifically, cations are deposited on the first sealing resin 11a and the second sealing resin 11b (arrow 1 in the drawing), and furthermore, the first sealing resin 11a and the second sealing resin 11b and the antireflection film (arrows 2 and 3 in the figure).

When the solar cell module 10 further generates power in the above-described state, some of the free electrons generated by the photoelectric effect are attracted not to the first electrode 12a on the back side, which is the positive electrode, but to the cations deposited on the interface. be done. It is presumed that PID occurs in the double-sided electrode type solar cell module due to such reactions taking place inside.

Based on the above speculation, it is considered that the power generation efficiency of the double-sided electrode type solar cell module 10 in which the frame 18 is grounded decreases when the ground potential of the second electrode 12b, which is the negative electrode, becomes negative due to power generation or the like. . For this reason, when the solar cell module 10 does not generate power, it is preferable to control each part so that the ground potential of the negative electrode does not become negative, for example, by insulating the solar cell module 10 . It is considered that a decrease in power generation efficiency in the solar cell module can be minimized by controlling the period during which the ground potential of the negative electrode is negative to a minimum.

(Example of circuit configuration)
A configuration example of the circuit of the power control device 30 according to this embodiment will be described with reference to FIG. FIG. 5 is a schematic diagram showing a configuration example of the circuit of the power control device 30. As shown in FIG.

Booster circuit 101 is non-insulated and has FET 108 , coil 109 and diode 110 . The drain of FET 108 is connected to coil 109 and the anode of diode 110 . One end of the coil 109 is connected to the positive input terminal 131 via the relay 105 and the other end is connected to the drain of the FET 108 and the anode of the diode 110 .

The relay 105 includes a first switch 151 a that switches between connection with the positive electrode of the solar cell module 10 via the positive input terminal 131 and a second switch that switches between connection with the negative electrode via the negative input terminal 132 . 151b and . Whether or not the first switch 151 a and the second switch 151 b are connected is switched according to the control signal generated by the switching control section 107 .

When the solar cell module 10 is generating power, a first control signal is transmitted from the switching control unit 107 to the booster circuit 101, and a second control signal is transmitted to the bidirectional PWM inverter 102, so that the solar cell module 10 Let us consider a case in which the power generated by the generator is output to the system power network 2 . At this time, the electromotive voltage _VPV of the solar cell module 10 is boosted to _Vout in FIG. be done. Assuming that V _out is 360 V here, due to the reverse conversion operation of the bidirectional PWM inverter 102 , the voltage to ground of the upper side of the two inputs connected from the right side of the booster circuit 101 is V _out /2, which is +180 V. , and a DC voltage of -180 V is applied to the lower side.

At this time, a DC-to-ground voltage of −180 V is applied to the negative electrode side of the solar cell module 10 via the negative input terminal 132 . On the other hand, the voltage to ground on the positive electrode side of the solar cell module 10 is −180 V+V _PV , where V _PV is the electromotive voltage of the solar cell module 10 at this time. In this way, the reverse conversion operation of the bidirectional PWM inverter 102 causes the voltage to ground on the negative electrode side to become negative, and at this time, the power generation efficiency of the solar cell module 10 gradually decreases as described with reference to FIG.

After that, it is assumed that the solar cell module 10 does not generate power due to sunset or the like, or the electromotive voltage in power generation falls below a predetermined voltage. The predetermined voltage is preferably set based on the electromotive voltage generated in the solar cell module 10 at night or in rainy weather.

When the solar cell module 10 does not generate power, the switching control unit 107 transmits a third control signal to the bidirectional DC/DC converter 104, transmits a second control signal to the bidirectional PWM inverter 102, and activates the power storage device. Consider the case where 20 operates to store power purchased from grid 2 . At this time, an AC voltage of 200 V is applied from the system power network 2 . After that, the forward conversion operation of the bidirectional PWM inverter 102 converts it into a DC voltage. Since the forward conversion operation of the bidirectional PWM inverter 102 accompanies a step-up action to achieve a high power factor, the voltage indicated as V _out in FIG. 5 is the DC voltage (200 V ×√2=282V), for example 360V.

At this time, of the two inputs connected from the right side of the drawing, the booster circuit 101 is applied with a DC voltage of +180 V to ground as V _out /2 on the upper side, and a DC voltage of -180 V is applied on the lower side. be done.

At this time, a DC-to-ground voltage of −180 V is applied to the negative electrode side of the solar cell module 10 via the negative input terminal 132 . This results in the generation of an electric field between the negative electrode and the cover glass 19 that reduces the power generation efficiency of the solar cell module 10, as described with reference to FIG. When both the first switch 151 a and the second switch 151 b of the relay 105 are turned off by the fourth control signal transmitted from the switching control unit 107 here, the solar cell module 10 is insulated from the power control device 30 . That is, no voltage is generated between the positive electrode and the negative electrode of the solar cell module 10 and no electric field is generated between the negative electrode and the cover glass 19 . As a result, it is possible to suppress a decrease in the power generation efficiency of the solar cell module 10 for the reason explained with reference to FIG. 4 .

With the circuit configuration as shown in FIG. When the electromotive voltage is below a predetermined voltage, each part can be controlled by a control signal to isolate the solar cell module 10 from the power control device 30 . As a result, it is possible to provide the power control device 30 capable of suppressing a decrease in power generation efficiency in the solar cell module 10 .

It is necessary to turn off both the first switch 151a and the second switch 151b of the relay 105 in FIG. 5 to isolate the solar cell module 10 from the power control device 30, for example, in the following cases. That is, when the power storage device 20 stores power purchased from the grid power network 2, when the power storage device 20 discharges the power and reversely flows (sells) the power to the grid power grid 2, or when the power storage device 20 discharges the power is used to drive an electric device (not shown). In these cases, voltage is applied to the right side of the booster circuit 101 . At this time, the switching control unit 107 insulates the solar cell module 10 so that the power generation efficiency of the solar cell module 10 does not decrease due to the influence of the voltage applied to the right input of the booster circuit 101 . Thereby, the power control device 30 can suppress a decrease in the power generation efficiency of the solar cell module 10 .

In the above description, the reason why the solar cell module 10 is insulated from the power control device 30 to suppress a decrease in power generation efficiency is that the power storage device 20 performs either storage or discharge with the grid power network 2. and the electromotive voltage in the solar cell module falls below a predetermined voltage. However, as long as it is possible to suppress a decrease in power generation efficiency, any trigger may be used. For example, the power control device 30 estimates a time period during which the solar cell module 10 does not generate power from information such as time information, calendar information, and weather forecast, and isolates the solar cell module 10 based on the estimated information. may control each part of

[Embodiment 2]
Embodiment 2 of the present invention will be described below with reference to FIGS. 1 and 6. FIG. For convenience of description, members having the same functions as those of the members described in the above embodiments are denoted by the same reference numerals, and description thereof will not be repeated.

(Configuration of photovoltaic power generation system)
The configuration of a photovoltaic power generation system 1A according to this embodiment is substantially the same as that of the first embodiment.

(Example of circuit configuration)
A configuration example of the circuit of the power control device 30A according to this embodiment will be described with reference to FIG. FIG. 6 is a schematic diagram showing a circuit configuration example of the power control device 30A. In this embodiment, the circuit configuration of the power control device 30A is basically the same as that of the first embodiment shown using FIG. 5, but a part of the configuration is different. In this embodiment, the relay 105A differs from that of the first embodiment in that it only includes a second switch 151b.

Here, it is assumed that the solar cell module 10 does not generate power and the electric power purchased from the system power network 2 is stored in the power storage device 20 as described with reference to FIG. 5 . At this time, when the second switch 151b of the relay 105A is turned off by the fifth control signal transmitted from the switching control unit 107, the negative electrode of the solar cell module 10 is insulated from the power control device 30A. That is, no voltage is generated between the positive electrode and the negative electrode of the solar cell module 10 and no electric field is generated between the negative electrode and the cover glass 19 . As a result, it is possible to suppress a decrease in the power generation efficiency of the solar cell module 10 for the reason explained with reference to FIG. 4 . Therefore, even with the circuit configuration shown in FIG. 6, it is possible to suppress a decrease in the power generation efficiency of the solar cell module 10 .

[Modification]
In each of the above embodiments, the power control device 30 may transmit and receive information with, for example, a HEMS (Home Energy Management System) controller (not shown). For example, the switching control unit 107 acquires history information about the power generation amount and power generation time of the solar cell module 10 from the HEMS controller, and based on the acquired history information, each unit controls a decrease in the power generation efficiency of the solar cell module 10. may be controlled.

[Example of realization by software]
The control block (especially the switching control unit 107) of the power control devices 30 and 30A may be implemented by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be implemented by software. .

In the latter case, the power control devices 30 and 30A are provided with computers that execute instructions of programs, which are software for realizing each function. This computer includes, for example, at least one processor (control device) and at least one computer-readable recording medium storing the program. In the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, a "non-temporary tangible medium" such as a ROM (Read Only Memory), a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the program may be further provided. Also, the program may be supplied to the computer via any transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. Note that one aspect of the present invention can also be implemented in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

〔summary〕
A power control device (30, 30A) according to aspect 1 of the present invention includes a double-sided electrode type solar cell module (solar cell module 10) having a frame (18) grounded, a power storage device (20) that stores and discharges power. ), and an external power control device for controlling power input/output in a photovoltaic power generation system (1, 1A) including the solar cell module, wherein the power storage device is connected to the power grid. When the electromotive voltage in the solar cell module is below a predetermined voltage, a control signal for disconnecting the solar cell module is generated.

According to the above configuration, when the power storage device is performing either storage or discharge with respect to the system power grid, and the electromotive voltage in the solar cell module is lower than the predetermined voltage, the power control device You can disconnect the module. This makes it possible to prevent the solar cell module from being affected by the voltage generated between the power storage device and the system power grid when the solar cell module is not effectively generating power. That is, in the solar cell module, generation of PID can be suppressed by preventing the generation of an electric field between the grounded frame and the electrode due to the voltage generated between the power storage device and the system power grid. Therefore, it is possible to provide a power control device capable of suppressing a decrease in the power generation efficiency of the double-sided electrode type solar cell module in a photovoltaic power generation system having a power storage device.

A power control device (30, 30A) according to aspect 2 of the present invention is the power control device (30, 30A) according to aspect 1, further comprising: a bidirectional DC/DC converter (104) to which the output voltage of the power storage device (20) is input; and a bidirectional inverter circuit (bidirectional PWM inverter 102), wherein the booster circuit and the bidirectional DC/DC converter are connected in parallel, and the bidirectional inverter circuit may be configured such that the output terminals connected in parallel are used as a DC input.

According to the above configuration, the power control device can cause either power storage or discharge between the power storage device and the grid power network by operating the bidirectional DC/DC converter and the bidirectional inverter circuit. . In addition, by disconnecting the solar cell module, the solar cell module can be prevented from being affected by the voltage generated by charging and discharging.

A power control device (30, 30A) according to aspect 3 of the present invention, in aspect 1 or 2, generates the control signal based on information about a time slot in which the solar cell module (10) does not generate power. may be configured.

According to the above configuration, the power control device can cut off the connection with the solar cell module during the time when the solar cell module does not generate power. As a result, it is possible to prevent a decrease in the power generation efficiency of the solar cell module during a period of time when the solar cell module does not generate power, such as at night.

A power control device (30, 30A) according to aspect 4 of the present invention is a power control device (30, 30A) according to any one of aspects 1 to 3, wherein the control signal causes only the connection to the negative electrode side of the output voltage of the solar cell module (10). It is good also as a structure cut|disconnected.

According to the above configuration, the power control device can cut off the connection with the negative electrode side of the output voltage of the solar cell module according to the control signal. As a result, for example, when the solar cell module is not generating power, it is possible to suppress the generation of an electric field presumed to be the cause of PID between the negative electrode of the solar cell module and the grounded frame.

A solar power generation system (1, 1A) according to aspect 5 of the present invention comprises a double-sided electrode type solar cell module (10) having a frame (18) grounded, a power storage device for storing and discharging power, and and the power control device (30, 30A) according to any one of modes 1 to 4. According to the above configuration, the same effects as in the first aspect are obtained.

The power control device (30, 30A) according to each aspect of the present invention may be realized by a computer. A control program for a power control device that causes a computer to implement the control device, and a computer-readable recording medium recording it are also included in the scope of the present invention.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

Reference Signs List 1, 1A photovoltaic power generation system 2 grid power network 10 solar cell module (double-sided electrode type solar cell module)
11a first sealing resin 11b second sealing resin 12a first electrode 12b second electrode 13 solar cell 14a first electrode busbar 14b second electrode busbar 15 back surface protection sheet 16 inner connector 17 output terminal 18 frame (outer frame)
19 cover glass 20 power storage device 30, 30A power control device 101 step-up circuit 102 bidirectional PWM inverter 103 AC reactor 104 bidirectional DC/DC converter 105, 105A relay 107 switching control unit (controller)
108 FETs
109 Coil 110 Diode 131 Positive Input Terminal 132 Negative Input Terminal 151a First Switch 151b Second Switch

Claims (5)

It is connected to a double-sided electrode type solar cell module whose frame is grounded, a power storage device that stores and discharges power, and an external system power network, and controls power input and output in a solar power generation system including the solar cell module. A power control device,
a bidirectional DC/DC converter to which the output voltage of the power storage device is input, a non-isolated booster circuit to which the output voltage of the solar cell module is input, and a bidirectional inverter circuit,
The output terminals of the booster circuit and the bidirectional DC/DC converter are connected in parallel, and the bidirectional inverter circuit uses the parallel-connected output terminals as DC inputs,
Between the power storage device and the system power network, storage of electricity from the bidirectional inverter circuit through the bidirectional DC/DC converter, and discharge from the bidirectional DC/DC converter through the bidirectional inverter circuit. and generating a control signal for disconnecting the solar cell module and the booster circuit when the electromotive voltage in the solar cell module is below a predetermined voltage. Control device. 2. The power control device according to claim 1, wherein the control signal is generated based on information regarding a time period during which the solar cell module does not generate power. 3. The power control device according to claim 1, wherein the control signal disconnects only the connection with the negative electrode side of the output voltage of the solar cell module. a double-sided electrode type solar cell module whose frame is grounded;
a power storage device that stores and discharges power;
A solar power generation system comprising the power control device according to any one of claims 1 to 3. A program for causing a computer to function as the power control device according to claim 1 .

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