JP2000068535A - Power converting device for solar power generation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To excellently recover deterioration by irradiated light by the applying reverse bias voltage in a power converting device for solar power generation wherein a bypass diode is parallel-connected to a solar battery module. SOLUTION: A plurality of solar battery arrays 1j, where the serially connected body of a bypass diode Dji and a relay contact point rji is series- connected to a solar battery module Mji, are connected to an inverter main circuit 6 through relays Aj and Bj. A relay coil Rji, with which the relay contact point rji is opened, is provided. The relays A3 and B3 are switched to the state of reverse bias by the relay control signal R3 sent from a control circuit 7, the relay contact point rji is turned off by exciting the relay coil Rji by driving the relay Cji controlled by the relay control signal Tji sent from the control circuit 7, and the deterioration by irradiated light is recovered by applying reverse bias voltage to the solar battery module Mji.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter for photovoltaic power generation, which applies a reverse bias voltage to a photovoltaic module to recover from light degradation.

[0002]

2. Description of the Related Art As environmental problems such as global warming are taken up on a global scale, a photovoltaic power generation system is attracting attention as an energy system with less environmental load.
FIG. 20 shows an example of a residential solar cell system that is currently spreading to general households. In general, a residential photovoltaic power generation system includes a plurality of solar cell arrays 51, a connection box 52 for connecting the plurality of solar cell arrays 51 via respective backflow prevention diodes 53, and a DC power collected by the connection box 52. Conversion to AC power synchronized with voltage
5 and a system interconnection inverter device 54 as a power converter for performing interconnection operation. At present, connection box 52
There is also a device in which the power supply system and the system interconnection inverter device 54 are integrated.

[0003] Photovoltaic power generation can be roughly divided into a power generation system for electric power intended to use the generated electric power for various purposes, and a power generation system for consumers used for fixed applications such as calculators and watches. There is. Until now, silicon crystal-based solar cells have been mainly used as power generation systems for electric power. However, since silicon crystal solar cells cannot be integrated, voltage and current values cannot be freely designed, and it is difficult to reduce the weight more than the current situation.
In addition, there is a problem that the supply amount of silicon wafers as raw materials is limited. Therefore, a solar cell system using an amorphous silicon thin film solar cell that can be integrated, reduced in weight and flexible, and can be manufactured with a small amount of source gas is currently being developed.

[0004] Amorphous silicon thin-film solar cells have features that they can be integrated, reduced in weight and flexible, can be manufactured by using a small amount of source gas, and can be reduced in cost. Currently attracting attention, there is a problem that light stability is poor. In other words, if the irradiation with sunlight is continued for a long time, the photoelectric conversion efficiency gradually decreases, and finally, compared with the initial photoelectric conversion efficiency immediately after the production of the amorphous silicon thin film solar cell, 10 to 10
The phenomenon of stabilization occurs when the temperature drops by 20%. This phenomenon is called "photo-deterioration" of amorphous silicon solar cells, and research has been conducted to elucidate the photo-deterioration phenomenon from various angles, but at present, the photo-deterioration phenomenon has not been elucidated. No method has been found to eliminate light degradation. For this reason, when building a solar power generation system using amorphous silicon thin-film solar power, etc., the total amount of power generation when the system is installed differs from the total amount of power generation when the system is used for several months. There is a problem that it becomes a photovoltaic power generation system. Further, when a photovoltaic power generation system is designed on the basis of the photoelectric conversion efficiency after photodeterioration, there is a problem that a solar cell having a larger area is required, resulting in an increase in cost. this is,
The problem is not limited to the amorphous silicon thin-film solar cell in which the photodegradation phenomenon appears remarkably, but is also common to a crystalline thin-film solar cell containing some microcrystals and other thin-film solar cells.

[0005] In order to solve the above-mentioned problem of light deterioration in the prior art, a power converter connected to a solar cell is used to apply a reverse bias voltage to the solar cell. . The solar cell can recover from light degradation by receiving sunlight in a reverse bias state. Therefore, in a power converter for photovoltaic power generation using DC power generated by a solar cell as an input, a reverse bias generation unit is configured to apply a reverse bias voltage to the solar cell over a predetermined period of insolation. The configuration is such that the deterioration of the characteristics of the solar cell is recovered.

An example of a prior art photovoltaic power converter for photovoltaic power generation designed to recover the photodegradation of a solar cell by applying a reverse bias voltage will be described below with reference to FIG. Related Japanese Patent Application No. 9-34774
No. 0). 1 ₁ , 1 ₂ ... 1 _n are solar cell arrays, 3
₁ , 3 ₂ ... 3 _n are backflow prevention diodes, 8 ₁ , 8 ₂ ... 8
_n is a relay, 6 is an inverter main circuit, 7 is a control circuit, 9
Is a grid-connected inverter, 10 is a calendar circuit, and 5 is a commercial system. In a state where all the relays 8 ₁ to 8 _n are connected to the contact a side, all the solar cell arrays ₁₁ to 8 _n are connected.
1 _n is connected in parallel to the inverter main circuit 6, and the direct current voltage generated in each of the solar cell arrays ₁₁ to 1 _n by irradiating the solar cell arrays ₁₁ to 1 _n with sunlight. Are supplied to the inverter main circuit 6 through the backflow prevention diodes 3 ₁ , 3 ₂ ... 3 _n . The control circuit 7 performs system operation with the commercial system 5 by executing current waveform control, maximum power follow-up control, interconnection protection control, and the like in the inverter main circuit 6. Now, it is assumed that the calendar circuit 10 operates to perform a function of recovering light deterioration of the solar cells of the solar cell array 1 _n . It sends a relay control signal R _n to the relay 8 _n from the control circuit 7, the contact b relay 8 _n
Switch to the side. Then, the solar cell array 1 _n is in a reverse connection state. DC voltage solar cell array ₁ 1 ~1 n-1 other than the solar cell array 1 _n occurs by receiving the sunlight is applied as a reverse bias voltage to the solar cell array 1 _n. This reverse bias voltage is applied to the solar cell array 1
_{If the} process is performed in a state where sunlight is irradiated on _n , the photodegradation of the solar cell modules constituting the solar cell array 1 _n is recovered.

[0007]

As shown in FIG.
The solar cell array 1 is configured by connecting a plurality of solar cell modules M in series. Such a series connection body may be called a solar cell string. By the way, in a solar cell string, when any one of the solar cell modules M is shaded, the sum of the output voltages of the solar cell strings is applied to the shaded solar cell module M and is damaged. In order to prevent this, a bypass diode Db is connected to each solar cell module M in parallel.

However, in the case of the solar cell array 1 in which the bypass diodes Db are connected in parallel as described above, when the reverse bias voltage is applied, the bypass diodes Db are directly bypassed to bypass the solar cell module M. The current flows, and the reverse bias voltage is not applied to the solar cell module M. Then, naturally, there is a problem that the photodegradation of the solar cell array 1 cannot be recovered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photovoltaic module capable of recovering from light deterioration satisfactorily even in a device having a bypass diode.

[0010]

The invention according to claim 1 is a power conversion device for photovoltaic power generation for recovering light deterioration by applying a reverse bias voltage to a photovoltaic module. The bypass diode is connected in parallel, and when the reverse bias voltage is applied, the bypass diode is disconnected, so that the current due to the reverse bias voltage does not pass through the solar cell module in a bypass manner, and the reverse bias voltage is reliably targeted. The voltage can be applied to the solar cell module, and the photodegradation recovery to an almost initial state can be performed satisfactorily.

According to a second aspect of the present invention, the switching means is inserted in series with the bypass diode, and the switching means is opened when a reverse bias voltage is applied. To exert the effect of.

According to a third aspect of the present invention, a solar cell module to be subjected to light degradation recovery is configured to use the power generated by the remaining solar cell modules as the reverse bias voltage. , The reverse bias voltage can be covered by the power generated by the photovoltaic power generation itself.

The invention according to claim 4 is suitable for a power conversion device for photovoltaic power generation using an amorphous silicon thin-film solar cell in which the solar cell module is an amorphous silicon thin-film solar cell and which needs to recover from light degradation.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a configuration diagram of a power converter for photovoltaic power generation according to a first embodiment of the present invention. An amorphous silicon thin film solar cell is used as the solar cell module. The first solar cell array 1 ₁ plurality of solar cell modules M _11,
M _12, M _13, are those of M ₁₄ become connected in series, the solar battery module M ₁₁ series of the bypass diode D ₁₁ and the relay contact r ₁₁ are connected in parallel, the solar cell module M ₁₂ is Bypass diode D ₁₂ and relay contact r ₁₂
Series body are connected in parallel with, the solar cell module M ₁₃ series of the bypass diode D ₁₃ and the relay contact r ₁₃ are connected in parallel, the bypass diode D ₁₄ and the relay contact r ₁₄ is the solar cell module M ₁₄ Are connected in parallel. Each relay contact r ₁₁ ~r ₁₄ is a b-contact type normally-on. Each relay contact r ₁₁ ~r ₁₄ is adapted to be independently controlled by the relay coil R ₁₁ to R _14. One end of each of the relay coil R ₁₁ to R ₁₄ is connected to the output terminal 2 ₁₁ on the high potential side of the solar cell array 1 _1, the control circuit 7 and the other end via a separate relay C ₁₁ -C _14
Is connected to the power supply terminal V _BB on the high potential side of Each of the relays C _{11 to} C ₁₄ is controlled by a relay control signal T from the control circuit 7.
It is controlled independently by ₁₁ through T _14.
The relays C _{11 to} C ₁₄ are included in the system interconnection inverter 9.

[0015] Although not shown, it is similarly configured second solar cell array 1 _2. That is, in the above description, the suffixes “ ₁ ”, “ ₁₁ ”, “ ₁₂ ”,
Instead of “ ₁₃ ” and “ ₁₄ ”, “ ₂ ”, “ ₂₁ ”, “ ₂₂ ”, “
₂₃ "and" ₂₄ ", the configuration is as shown by the same description. The n-th solar cell array 1 _n is also configured in the same manner. “ ₁ ”, “ ₁₁ ”, “ ₁₂ ”, “ ₁₃ ”,
_{"14" "n"} instead _{of, "n1", "n2"} , "n3", "
_n4 ", the configuration is as shown by the same description. Further, although not shown, the third to n-1th solar cell arrays have the same configuration. I have.

The output terminals 2 ₁₁ to 2 _n1 on the high potential side of each of the solar cell arrays 1 ₁ to 1 _n are connected to a backflow prevention diode 3 _1.
Inverter main circuit 6 in the system interconnection inverter 9 via a to 3 _n and the relay A ₁ to A _n of the transfer format
Is connected to the high potential side power supply input line 6a. The output terminal 2 ₁₂ to 2 _n2 of the low potential side of the solar cell array 1 ₁ to 1 _n denotes a relay B ₁ ~ each transfer format
It is connected to the low potential side power supply input line 6b of the inverter main circuit 6 via _Bn . Each relay A ₁ to A _n of the contact a how a line connecting the common high-potential power supply line 11
The high-potential-side power supply line 11a is connected to the high-potential-side power supply input line 6a of the inverter main circuit 6. The line that connects the contacts a of the relays B _{1 to} B _n in common is a low-potential-side power supply line 11 b, which is connected to a low-potential-side power supply input line 6 b of the inverter main circuit 6. I have.

To enable each solar cell array to be reverse-biased by the photovoltaic power generated by the other solar cell array groups, the contacts b of the relays B _{1 to} B _n are connected to the high-potential-side power supply line 11a. , And each of the relays A _{1 to An}
Is connected to the low potential side power supply line 11b.

The pair of relays A ₁ and B ₁ are configured as interlocking relays, and are controlled by a relay control signal R ₁ from the control circuit 7. The pair of relays A ₂ and B ₂ are configured as interlocking relays, and are controlled by a relay control signal R ₂ from the control circuit 7. Similarly, the pair of relays A _n and B _n are also configured as interlocking relays, and are controlled by a relay control signal R _n from the control circuit 7.

The system interconnection inverter 9 includes an inverter main circuit 6, a control circuit 7 for executing current waveform control, maximum power follow-up control, interconnection protection control, and the like in the inverter main circuit 6, a calendar circuit 10, and the like. regurgitation preventing diode 3 ₁ to 3 _n described, relay A ₁ to A _n, the relay B ₁ .about.B _n, and a like relay C ₁₁ -C _n4. The output side of the inverter main circuit 6 in the system interconnection inverter 9 is connected to the commercial system 5 so as to be capable of interconnection operation.

Next, the operation will be described. Relays A _{1 to An}
When all the relays B _{1 to} B _n are connected to the contact “a”, all the solar cell arrays ₁₁ to 1 _n are connected in parallel to the inverter main circuit 6. by sunlight is irradiated to 1 ₁ to 1 _n, the DC voltage generated in the solar cell array 1 ₁ to 1 _n is supplied to the inverter main circuit 6 through a blocking diode 3 ₁ to 3 _n. The control circuit 7 includes an inverter main circuit 6
, The system operation with the commercial system 5 is performed by executing current waveform control, maximum power follow-up control, interconnection protection control, and the like.

[0021] Now, when you try to recover the light deterioration of the solar cell array _{1 1 ~1 n.} Light degradation recovery switch 1 manually
When 2 is turned on, sends a relay control signal R ₁ from the first solar cell array 1 ₁ control circuit 7 to the relay A _1, B ₁ linked in for the contact relay A _1, B _1, respectively Switch to b side. Then, the output terminal 2 ₁₁ on the high potential side of the _first solar cell array ₁₁ is connected to the inverter main circuit 6.
Together with disconnected from the high potential power supply input line 6a and the high-potential-side power supply line 11a, the output terminal 2 ₁₂ on the low potential side is disconnected from the low potential side power supply input line 6b and the low-potential-side power supply line 11b, the low potential side Output terminal 2
₁₂ Relay A ₂ to A _n of the other solar cell array groups
Is connected to the high potential side power supply line 11a which is connected to the contact a, the output terminal 2 ₁₁ on the high potential side low potential side is connected to contact b of the relay B ₂ .about.B _n for different solar cell array groups is connected to the power supply line 11b, the first solar cell array 1 ₁ becomes reverse biased. However, in the first solar cell array 1 _1, relay contact r ₁₁ ~r connected in parallel to each solar cell module M ₁₁ ~M _14
If any one of ₁₄ is kept on, the low potential side output terminal 2 ₁₂ inverted to a high potential by the reverse bias voltage
Current flows from the solar cell module M ₁₁ via the bypass diodes D _{11 to} D ₁₄ to the output terminal 2 ₁₁ on the high potential side inverted to the low potential.
A reverse bias is not applied against ~M _14, Therefore, the restoration of photodegradation is not performed. Therefore, in the first embodiment, to turn on the relay C ₁₁ by sending a relay control signal T ₁₁ to the relay C ₁₁ from the control circuit 7, a power supply terminal of the first relay coil R ₁₁ the control circuit 7 Connect to V _BB . The current from the power supply terminal V _BB is applied to the relay C ₁₁
Through the first relay coil R ₁₁ through energized the relay coil R _11, it results to flow to the output terminal 2 ₁₁ on the high potential side which is inverted to the low potential, the first solar cell modules M
Relay contact r ₁₁ connected in parallel to the ₁₁ is turned off, the bypass diode D ₁₁ connected in series to the relay contact r ₁₁ first
It will be disconnected from the solar cell module M _11. Accordingly, the current of the first solar cell array 1 ₁ other than the DC voltage by the solar power generation of the solar cell array group, the high-potential power supply line 11a → relay B ₁ contacts b →
In relay contacts r ₁₃ and the bypass diode D ₁₃ → on-state in the first of the first solar cell module M ₁₁ → relay contact r ₁₂ and bypass in the on-state diode D ₁₂ → on-state of the solar cell array 1 ₁ Relay contact r ₁₄
And the bypass diode D ₁₄ → the output terminal 2 ₁₁ on the high potential side inverted to the low potential → the backflow prevention diode 3 ₁ → the contact b of the relay A ₁ → the power supply line 11b on the low potential side, and the first solar cell since the reverse bias voltage is applied to the module M _11, photodegradation of the first solar cell module M ₁₁ is restored.

Next, the control circuit 7 outputs the relay control signal T ₁₁
Together to return the relay contact r ₁₁ to the ON state by demagnetizing the relay coil R ₁₁ blocks the next relay C
Turn on the relay C ₁₂ sends out a relay control signal T ₁₂ relative to _12, to excite the second relay coil R _12. Accordingly, the relay contact r ₁₂ connected in parallel to the second solar cell module M ₁₂ is turned off, the bypass diode D ₁₂ is disconnected from the second solar cell module M _12, the second solar cell module M ₁₂ since the reverse bias voltage is applied, photodegradation of the second solar cell module M ₁₂ is restored. Then, the control circuit 7 causes return the relay contact r ₁₂ to the ON state by blocking relay control signals T _12, to turn on the relay C ₁₃ by sending a relay control signal T ₁₃ for the next relay C ₁₃ , by energizing the third relay coil R _13, relay contact r ₁₃ is turned off, the bypass diode D ₁₃ is the third solar battery module M ₁₃
Disconnected from, since a reverse bias voltage is applied to the third solar battery module M _13, photodegradation of the third solar battery module M ₁₃ is restored. Further, the control circuit 7
Along with restoring the relay contact r ₁₃ to the ON state by blocking relay control signals T _13, to turn on the relay C ₁₄ by sending a relay control signal T ₁₄ for the next relay C _14, fourth relay by energizing the coil R _14, relay contacts r ₁₄ is turned off, the bypass diode D ₁₄ is disconnected from the fourth solar cell module M _14, a reverse bias voltage is applied to the fourth solar cell module M ₁₄ To
The photodegradation of the fourth solar cell module M ₁₄ is restored. Thereafter, the relay C ₁₄ to interrupt the relay control signal T ₁₄
Is returned to the on state, and the relay control signal R ₁
And the pair of relays A ₁ and B ₁ are respectively returned to the contact a side. As described above, the recovery of photodegradation of the first solar cell array 1 ₁ of the solar battery module M ₁₁ ~M ₁₄ is completed. Then performs in the same manner as described above successively photodegradation recover the second solar cell each solar cell module M ₂₁ ~M ₂₄ of array 1 ₂ (not shown). The same sequential photodegradation recovery against in the same manner the solar cell modules of each solar cell array, finally, also the solar cell modules M _n1 ~M _n4 of the solar cell array 1 _n of the n Light degradation recovery is performed sequentially in the same manner as described above. In either case,
The reverse bias voltage for the photovoltaic array targeted for the photodegradation recovery is covered by the DC voltage generated by the photovoltaic power generation of the photovoltaic arrays other than the photodegradation recovery target. Also,
Light deterioration recovery is performed on condition that the solar cell array to be subjected to light deterioration recovery is irradiated with sunlight. If the DC power from the photovoltaic power generation has a margin, the DC power is also supplied to the inverter main circuit 6 within the range until the parallel array output decreases to the minimum voltage value required for reverse bias during the light deterioration recovery operation. It is also possible to supply the power to perform the interconnection operation with the commercial system 5.

The calendar circuit 10 can also periodically recover from light deterioration. The calendar circuit 10 outputs a reverse bias application command S to the control circuit 7 at a predetermined date and time registered in advance. The control circuit 7 that has received the reverse bias application command S performs light degradation recovery of all the solar cell modules by the same operation as described above for a predetermined period.
At this time, the control circuit 7 controls the inverter main circuit 6 so as to reduce the inverter output to a level at which a predetermined reverse bias voltage can be obtained. The calendar circuit 10 has a memory function, and can set the time zone for outputting the reverse bias application command in the morning and evening hours with less solar radiation according to the season.

All the solar cell modules may be amorphous thin film solar cells, crystalline thin film solar cells or other thin film solar cells. Instead of using a relay as the connection switching means, an analog switch such as a semiconductor switch may be used. Instead of connecting each one end of the relay coil _{R 11 ~R 14 ... R n1 ~R} n4 to the output terminal 2 ₁₁ on the high potential side, it may be connected to the ground GND of the control circuit 7.

[Second Embodiment] On the premise of the configuration of the first embodiment, each of the solar cell modules M _{j1 to} M _j4 of the solar cell array 1 _j (j = 1, 2,... Instead of applying the reverse bias voltage, the reverse bias voltage may be applied to all the solar cell modules M _{j1 to} M _j4 at the same time. FIG. 2 shows a main part of the configuration. The relay coils R _{j1 to} R _j4 are connected in series, and one relay C _j controls on / off.

[Third Embodiment] A photovoltaic power conversion device according to a third embodiment includes individual solar cell arrays 1
_j (j = 1, 2,... n) is a parallel connection of m solar cell strings. FIG. 3 shows the configuration of the j-th single solar cell array 1 _j . The solar cell array 1 _j is composed of m solar cell strings S _j1 to 1 to m.
S _jm . Of these, only the first solar cell string S _j1 and the m-th solar cell string S _jm are illustrated, and the illustration is omitted. The first solar cell string S _j1 includes a plurality of solar cell modules M _j11 ,
M _j12 , M _j13 , M _j14 and backflow prevention diode DD
_j1 are those of formed by serially connected solar cell strings S _jm of the m, a plurality of photovoltaic modules M _JM1, M
_jm2 , _Mjm3 , _Mjm4 and backflow prevention diode DD _jm
Are connected in series. Solar cell module M
_{j11, M j12, M j13,} M j14 group is connected to the high potential power supply output line 13a via a blocking diode DD _j1, one end of the first solar cell module M _j11 the low potential side power supply output line 13b It is connected. The group of solar cell modules M _jm1 , M _jm2 , M _jm3 , M _jm4 is connected to a high-potential-side power output line 13a via a backflow prevention diode DD _jm.
, _And one end of the first solar cell module M _jm1 is connected to the low-potential-side power output line 13b. The solar cell module M _j11 series of the bypass diode D _j11 and the relay contact r _j11 are connected in parallel, series body of the bypass diode D _j12 and the relay contact r _j12 are connected in parallel to the solar cell module M _j12, the solar cell module M _j13 series of the bypass diode D _j13 and the relay contact r _j13 are connected in parallel, the bypass diode D _j14 the solar cell module M _j14 and relay contact r
A series body with _j14 is connected in parallel. Each relay contact r
_j11 to _rj14 are _normally- on b-contact systems. Each relay contact r _j11 ~r _j14 each relay coil R
_{j11 to Rj14} are independently controlled. One end of each of the relay coils R _{j11 to} R _j14 is connected to the high-potential-side power output line 13a of the solar cell array 1 _j ,
The other end is connected to a power supply terminal V _BB of the high potential side of the control circuit 7 via a separate relay C _j1 -C _j4. Further, each of the relays C _{j1 to} C _j4 is a relay control signal T _j1 to
It is controlled independently by T _j4 . The relays C _{j1 to} C _j4 are included in the grid-connected inverter 9.
The same applies to the later solar cell strings. Regarding the m-th solar cell string S _jm , the suffix “ _j1 ”, “ _j11 ”, “
" _jm ", instead of " _j12 ", " _j13 ", " _j14 "
When " _jm1 ", " _jm2 ", " _jm3 ", and " _jm4 " are replaced, the configuration is as shown by the same description.

FIG. 4 shows the overall configuration of a photovoltaic power conversion device in which n solar cell arrays 1 _j (j = 1, 2,... N) having the above configuration are connected in parallel. Other configurations are basically the same as those in the first embodiment (FIG. 1), and thus description thereof is omitted.

Next, the operation will be described. Relays A _{1 to An}
In a state where all the relays B _{1 to} B _n are connected to the contact a side, all the string-structured solar cell arrays ₁₁ to 1 _n are connected in parallel to the inverter main circuit 6. by sunlight is irradiated to the solar cell array 1 ₁ to 1 _n of the string configuration, the inverter main circuit 6 DC voltage generated in the solar cell array 1 ₁ to 1 _n via a blocking diode 3 ₁ to 3 _n Supplied to The control circuit 7 performs system operation with the commercial system 5 by executing current waveform control, maximum power follow-up control, interconnection protection control, and the like in the inverter main circuit 6.

Next, the operation of light deterioration recovery will be described. In the same manner as in the first embodiment, each of the solar cell arrays is sequentially subjected to light degradation recovery from one of the solar cell arrays, and one of the solar cell arrays has one in each solar cell string.
The reverse bias voltage is applied to each of the solar cell modules. The feature of the second embodiment is that, in the photodegradation recovery in one solar cell array _1j , a plurality of solar cell strings _{Sj1 to} Sj1 to _Sj are provided. _{In jm} , a reverse bias voltage is applied to each solar cell module of the same rank at the same time.

[0030] Now, when you try to recover the light deterioration of the solar cell array _{1 1 ~1 n.} Light degradation recovery switch 1 manually
When 2 is turned on, sends a relay control signal R ₁ from the first solar cell array 1 ₁ control circuit 7 to the relay A _1, B ₁ linked in for the contact relay A _1, B _1, respectively Switch to b side. Then, the first high-potential power supply output line 13a of the solar cell array 1 ₁ is disconnected from the high-potential power supply input line 6a and the high-potential-side power supply line 11a of the inverter main circuit 6, low potential side power supply output line 13b is disconnected from the low potential side power supply input line 6b and the low-potential-side power supply line 11b, the low-potential power supply output line 13b is high potential is connected to the contact a of relay a ₂ to a _n of the other solar cell array groups connected to the side power source line 11a, the high-potential power supply output line 13a the relay B ₂ ~ for other solar array group
Low-potential-side power supply line 11 connected to contact b of _Bn
b, the first solar cell array ₁₁ is in a reverse bias state. Then, turn on the relay C ₁₁ by sending a relay control signal T ₁₁ to the relay C ₁₁ from the control circuit 7, a first relay of all solar cell strings S _j1 to S _jm of the first through m connecting the coil R ₁₁₁ to R _1m1 to the power supply terminal V _BB of the control circuit 7. The relay coil R ₁₁₁ current from the power source terminal V _BB passes through the first relay coil R ₁₁₁ to R _1m1 all via the relay C ₁₁ to R
Exciting the _1m1, results to flow to the high potential power supply output line 13a which is inverted to the low potential, the relay contacts of all parallel connected to the first solar cell module M ₁₁₁ ~M _1m1 r ₁₁₁
~r _1m1 is turned off, the relay contact r ₁₁₁ ~r _1m1
Are connected in series with the bypass diodes D _{111 to} D _1m1 .
It will be disconnected from the solar cell module M ₁₁₁ ~M _1m1. Accordingly, the current of the first solar cell array 1 ₁ other than the DC voltage by the solar power generation of the solar cell array group, the high potential power supply line 11a → the relay B ₁ contacts b → first solar cell array 1 ₁ All the first solar cell modules M _{111 to} M _1m1 → relay contacts r _{112 to} r _1m2 and bypass diode D ₁₁₂ to ON state
D _{1 m @ 2} → relay contact is in the ON state r ₁₁₃ ~r _{1 m @ 3} and the bypass diode D ₁₁₃ to D _{1 m @ 3} → relay contact is in the ON state _{r 114} ~r 1m4 and the bypass diode D
₁₁₄ ~D _1m4 → the path of the backflow prevention diode DD ₁₁ ~DD _1m → low potential to invert the high-potential power supply output line 13a → blocking diode 3 ₁ → contact b → the low-potential power source line 11b of the relay A ₁ flow, because all of the first reverse bias voltage at the same time the solar cell module M ₁₁₁ ~M _1m1 is applied, the first solar cell modules M ₁₁₁ ~
The light degradation of M _1m1 is recovered.

Next, the control circuit 7 outputs the relay control signal T₁₁
Cut off the relay coil R₁₁₁ ~ R_1m1 Degaussing
And relay contact r₁₁₁ ~ R_1m1 Is turned back on.
Both are the next relay C₁₂For the relay control signal T₁₂To
Send and relay C₁₂Turn on all second relays
Coil R₁₁₂ ~ R_1m2 To excite. Thereby, the second
Solar cell module M₁₁₂ ~ M_1m2 Relay connected in parallel
Contact r₁₁₂ ~ R_1m2 Is turned off and the bypass diode
D₁₁₂ ~ D_1m2 Is the second solar cell module M₁₁₂ ~ M
_1m2 Separated from all the second solar cell modules
Le M₁₁₂ ~ M_1m2 Reverse bias voltage is applied to
All these second solar cell modules M₁₁₂ ~ M
_1m2 Light degradation is recovered. Next, the control circuit 7
ー Control signal T₁₂And relay contact r₁₁₂ ~ R_1m2 To
After returning to the ON state, the next relay C₁₃Against
Relay control signal T₁₃And relay C₁₃Turn on
And the third relay coil R₁₁₃ ~ R_1m3 To excite
The relay contact r₁₁₃ ~ R_1m3 Is turned off and
Pass diode D₁₁₃ ~ D_1m3 Is the third solar cell module
M₁₁₃ ~ M_1m3 Disconnected from all the third fat
Positive battery module M₁₁₃~ M_1m3 Reverse bias voltage
All these third solar cell modules
Le M₁₁₃ ~ M_1m3 Light degradation is recovered. In addition, control
The circuit 7 has a relay control signal T₁₃And relay contact r
₁₁₃ ~ R_1m3 To the ON state, and
Leh C₁₄For the relay control signal T₁₄Send out the relay
C₁₄Is turned on, and the fourth relay coil R₁₁₄ ~ R_1m4 To
By energizing, the relay contact r₁₁₄ ~ R_1m4 Is off
And the bypass diode D₁₁₄ ~ D_1m4 Is the fourth thick
Positive battery module M₁₁₄ ~ M_1m4 Disconnected from everything
Fourth solar cell module M₁₁₄ ~ M_1m4 Reverse bi
As voltage is applied, all these fourth solar
Battery module M₁₁₄ ~ M_1m4 Light degradation is recovered.
Then, the relay control signal T₁₄And relay C₁₄The
Return to the ON state and the relay control signal R ₁ Block
Disconnect and relay A₁ , B₁ To the contact a side respectively
Let it. As described above, the first solar cell array 1₁ 
Solar cell module M₁₁₁ ~ M₁₁₄ ... M_1m1 ~ M_1m4 
The recovery from the light degradation of is completed. Next, the second solar cell
Array 1_TwoEach solar cell module M₂₁₁ ~ M₂₁₄ ... M
_2m1 ~ M_2m4 For light degradation recovery in the same manner as above
I do. Similarly, each solar cell of each solar cell array
Perform the same sequential light degradation recovery on the module,
Finally, the n-th solar cell array 1_n Each solar cell module
M_n11 ~ M_n14 ... M_nm1 ~ M_nm4 And above
Similarly, light deterioration recovery is sequentially performed. For calendar circuit 10
This operation is similar to that of the first embodiment.

Note that all the solar cell modules M _j11
Configuration as well as the relay coil R _j11 to R _j14 connected in series may be used according to the second embodiment with respect ~M _j14, likewise, exemplary for all of the solar cell module M _JM1 ~M _JM4 Similar to the configuration of the second embodiment, series-connected relay coils R _{jm1 to} R _jm4 may be used.

[Embodiment 4] FIG. 5 corresponds to one solar cell string S _j1 in the solar cell array 1 _j of FIG. High-potential power supply output line 13a to be connected to the anode of the blocking diode 3 _j and the relay B _j
Is connected to the power distribution box 15 in a state where the low-potential-side power output line 13b to be connected to the power supply line 13b is connected between the string connectors 14a and 14b. The cathode K of the first solar cell module M _j11 is connected to the module connector 16.
It is connected to the low-potential-side power supply output line 13b via the negative electrode terminal (a) (a). First solar cell module M
The anode A of _j11 is connected to the negative terminal (○-) of the module connector 16b via the positive terminal (○ +) of the module connector 16a. In addition, "○ +", "○
"-" Is used for convenience due to restrictions in the description of the specification.
The negative terminal (○-) of the module connector 16b is connected to the cathode K of the second solar cell module _Mj12 , and the second solar cell module The anode A of _Mj12 is connected to the negative terminal (○-) of the module connector 16c via the positive terminal (○ +) of the module connector 16b, and the negative terminal (○-) of the module connector 16c is connected to the third sun. Connected to the cathode K of the battery module _Mj13 ,
Of the solar cell module _Mj13 is connected to the negative terminal ( _負極 -) of the module connector 16d via the positive terminal (○ +) of the module connector 16c.
The negative terminal of the module connector 16d (○ -) is connected to the cathode K of the fourth solar cell modules M _j14, the anode A of the fourth solar cell module M _j14 is through a positive terminal of the module connector 16d (○ +) The anode of the backflow prevention diode _DDj1 is connected to the anode of the backflow prevention diode _DDj1 , and the cathode of the backflow prevention diode _DDj1 is connected to the high potential side power supply output line 13a in the distribution box 15.

[0034] The first solar cell module M _j11 series of the bypass diode D _j11 and the relay contact r _j11 are connected in parallel, the second solar cell module M _j12 bypass diode D _j12 and relay contact r _{j12 Are} connected in parallel, a series body of a bypass diode D _j13 and a relay contact r _j13 is connected in parallel to the third solar cell module M _j13, and a bypass diode D is connected to the fourth solar cell module M _j14. A series body of _j14 and a relay contact r _j14 is connected in parallel. Each relay contact r _{j11 -r
j14} is a _normally- on b-contact type. Each relay contact r _j11 ~r _j14 each relay coil R _j11 to R _j14
Is controlled independently by the One end of each of the relay coils R _{j11 to} R _j14 is connected to the high-potential-side power output line 13a of the solar cell string S _j1 , and the other end is connected to the string connectors 14a,
Four control signal lines 1 wired between 14b
7a to 17d, and each control signal line 1
7a~17d is connected to the power supply terminal V _BB of the high potential side of the control circuit 7 via a separate relay C _j1 -C _j4. The relays C _{j1 to} C _j4 are independently controlled by relay control signals T _{j1 to} T _j4 from the control circuit 7. The relays C _{j1 to} C _j4 are included in the grid-connected inverter 9. The same applies to the later solar cell strings.

FIG. 6 shows a solar cell array 1 _{j in} which m solar cell strings S _j1 having the above configuration are connected in parallel.
Are further connected in parallel to show the entire configuration of the photovoltaic power conversion device. The configuration of a solar cell array 1 _j composed of a parallel connection of solar cell strings S _{j1 to} S _jm is basically the same as that of the third embodiment (FIG. 3). The connection configuration with the grid interconnection inverter 9 is basically the same as that of the third embodiment (FIG. 4). That is, each of the solar cell arrays ₁₁ to
The high-potential power output line 18a and the low-potential power output line 13 connected to the 1 _n high-potential power output line 13a
The low-potential-side power supply output lines 18b connected to the line b are connected to the system interconnection inverter 9, respectively. The system interconnection inverter 9 includes an inverter main circuit 6, a control circuit 7 for executing current waveform control, maximum power follow-up control, interconnection protection control, and the like in the inverter main circuit 6, a calendar circuit 10, and a plurality of backflow prevention circuits. and the diode 3 ₁ to 3 _n, and a plurality of relay a ₁ to a _n and the relay B ₁ ~B _n, relay C ₁₁
Is constructed from such ~C ₁₄ ... C _n1 ~C _n4.

[0036] Each high-potential power supply output line 18a via a blocking diode 3 ₁ to 3 _n is connected to the common terminal of the relay A ₁ to A _n, the high potential side of the contact a of the relay inverter main circuit 6 It is connected to the power input line 6a. Each low-potential-side power output line 18b is connected to relays B _{1 to} B
is connected to the _n common terminal, contact a of the relay is connected to the low potential side power supply input line 6b of the inverter main circuit 6.

Next, the operation will be described. Relays A _{1 to An}
In a state where all the relays B _{1 to} B _n are connected to the contact a side, all the string-structured solar cell arrays ₁₁ to 1 _n are connected in parallel to the inverter main circuit 6. by sunlight is irradiated to the solar cell array 1 ₁ to 1 _n of the string configuration, the inverter main circuit 6 DC voltage generated in the solar cell array 1 ₁ to 1 _n via a blocking diode 3 ₁ to 3 _n Supplied to The control circuit 7 performs system operation with the commercial system 5 by executing current waveform control, maximum power follow-up control, interconnection protection control, and the like in the inverter main circuit 6.

Next, the operation of the optical degradation recovery will be described. In the same manner as in the third embodiment, each one of the solar cell arrays sequentially undergoes photodegradation and recovery, and one of the solar cell arrays has one of the solar cell strings.
Than is a reverse bias voltage is applied to the solar cell module by One, but as with the fourth embodiment of the third embodiment, in the photodegradation recovery in one solar cell array 1 _j, a plurality of In the solar cell strings S _{j1 to} S _jm , a reverse bias voltage is applied to each of the solar cell modules in the same order at the same time.

Now, the solar cell array 1₁ ~ 1_n Light degradation
Trying to recover. Light degradation recovery switch 1 manually
2 is turned on, the first solar cell array 1₁ about
Interlocking Relay A₁ , B₁ From the control circuit 7
Ray control signal R₁ And relay A₁ , B₁ Each
The contact is switched to the contact b side. Then, the first solar cell array
I1₁ Of the high potential side power supply output line 18a
Disconnected from the high-potential-side power supply input line 6a of the circuit 6
At the same time, the low-potential-side power output line 18b is
Power supply input line 6b
In 18b is a relay A for another solar cell array group.
_Two , B_Two ~ A_n , B_n High potential connected to contact a of
Connected to the high-potential-side power supply output line
13a is a relay A for another solar cell array group._Two 
~ A_n Low-potential-side power line 1 connected to the contact b
1b, the first solar cell array 1₁ Is a reverse via
State. Next, the relay C₁₁To
The relay control signal T₁₁And relay C₁₁On
And all the solar cell strings from the first to the m-th
S₁₁~ S_1mFirst relay coil R₁₁₁ ~ R_1m1 Control
Power supply terminal V of control circuit 7_BBConnect to Power supply terminal V_BBFrom
Current of relay C₁₁Through all first relay coils
Le R₁₁₁ ~ R_1m1 Through this relay coil R₁₁₁ ~ R
_1m1 And the high-potential-side power output
As a result, the flow to all the first solar cell modules
Jules M₁₁₁ ~ M_1m1 Relay contact r connected in parallel₁₁₁ 
~ R_1m1 Is turned off and this relay contact r₁₁₁ ~ R_1m1 
To the bypass diode D connected in series₁₁₁ ~ D_1m1 Is the first
Solar cell module M₁₁₁ ~ M_1m1 Disconnected from
Will be. Therefore, the first solar cell array 1₁ Less than
DC voltage from the solar array outside
Current flows from the high potential side power supply line 11a to the relay B ₁ Contact
Point b → first solar cell array 1₁ Inverted to high potential
Low potential side power output line 18b → each solar cell string
S₁₁~ S_1mLow-side power supply output
In 13b → first solar cell array 1₁ The first of all
Solar cell module M₁₁₁ ~ M_1m1 → in the ON state
Relay contact r₁₁₂ ~ R_1m2 And bypass diode D
₁₁₂ ~ D_1m2 → Relay contact r in ON state₁₁₃ ~ R
_1m3 And bypass diode D₁₁₃ ~ D_1m3 → ON
Relay contact r₁₁₄ ~ R_1m4 And bypass die
Aether D₁₁₄ ~ D_1m4 → Each solar cell string S₁₁~
S_1mHigh-side power output line 13 inverted to a low potential
a → first solar cell array 1₁ High inverted to low potential of
Potential side power output line 18a → backflow prevention diode 3₁ 
→ Relay A₁ Contact b → low potential side power supply line 11b
All the first solar cell modules
M₁₁₁ ~ M_1m1 Reverse bias voltage is applied to the
Therefore, the first solar cell module M₁₁₁ ~ M_1m1 
Light degradation is recovered.

Next, the control circuit 7 outputs the relay control signal T ₁₁
Together to return the relay contact r ₁₁₁ ~r _1m1 to the ON state by demagnetizing the relay coil R ₁₁₁ to R _1m1 shut off the relay C sends out a relay control signal T ₁₂ for the next relay C _{12 12} is turned on to excite all the second relay coil R ₁₁₂ to R _{1 m @ 2.} Accordingly, the relay contact r ₁₁₂ ~r _{1 m @ 2} of the parallel connection to the second solar cell module M ₁₁₂ ~M _{1 m @ 2} is turned off, the bypass diode D ₁₁₂ to D _{1 m @ 2} is the second solar cell module M ₁₁₂ ~M
Disconnected from _{1 m @ 2,} since the reverse bias voltage is applied to all of the second solar cell module M ₁₁₂ ~M _1m2,
All of these second solar cell modules M _{112 to} M _112
1m2 light degradation is recovered. Then, the control circuit 7 causes return the relay contact r ₁₁₂ ~r _{1 m @ 2} to the ON state by blocking relay control signals T _12, relay C ₁₃ by sending a relay control signal T ₁₃ for the next relay C ₁₃ was turned on, by energizing the third relay coil R ₁₁₃ to R _{1 m @ 3,} the relay contact r ₁₁₃ ~r _{1 m @ 3} is turned off, the bypass diode D ₁₁₃ to D _{1 m @ 3} third solar battery module M ₁₁₃ ~M disconnected from _{1 m @ 3,} since all of the third solar battery module M ₁₁₃ ~M _{1 m @ 3} in the reverse bias voltage is applied, light degradation of all of these third solar battery module M ₁₁₃ ~M _{1 m @ 3} is recovered. Further, the control circuit 7 relay contact r blocks the relay control signal T ₁₃
The ₁₁₃ ~r _{1 m @ 3} together is returned to the ON state, and turns on the relay C ₁₄ by sending a relay control signal T ₁₄ for the next relay C _14, to excite the fourth relay coil _{R 114} ~R 1m4 the relay contacts _{r 114} ~r 1m4 is turned off, the bypass diode _{D 114} ~D 1m4 disconnected from the fourth solar cell modules _{M 114} ~M 1m4, all of the fourth solar cell modules _{M 114} ~M 1m4 since the reverse bias voltage is applied, light degradation of all of these fourth solar cell modules _{M 114} ~M 1m4 is recovered.
Thereafter, the returning the relay C ₁₄ to the ON state by blocking relay control signals T _14, to return the relay A _1, B ₁ pair to interrupt the relay control signal R ₁₁₁ to the contact a side. As described above, the first solar cell array 1
₁ solar cell module M _{111 to} M ₁₁₄ … M _{1m1 to} M
_1m4 light degradation recovery is completed. Then, the second solar cell array 1 each solar cell ₂ module M ₂₁₁ ~M ₂₁₄
... For M _{2m1 to} M _2m4 , light deterioration recovery is sequentially performed in the same manner as described above. The same sequential photodegradation recovery against in the same manner the solar cell modules of each solar cell array, and finally, the solar battery module M of a solar array 1 _n of the n _n11 ~M _n14 ... M Light degradation recovery is sequentially _performed for _{nm1 to Mnm4 in the same} manner as described above. Calendar circuit 1
The operation based on 0 is the same as in the first embodiment.

[Fifth Embodiment] In the fifth embodiment, three control signal lines are provided in the distribution box. That is, as shown in FIG. 7, the three control signal lines 19 a to 19 wired in the distribution box 15.
c. FIG. 7 is a sectional view of the solar cell array _1j shown in FIG.
One solar cell string S _j1 . Control signal lines 19a to 19c are wired between the string connectors 14a and 14b in the distribution box 15. One end of the relay coil R _j11 is connected to the first control signal line 19a, and the other end is a backflow prevention diode d _j11.
To the second control signal line 19b. One end of the relay coil _Rj12 is connected to the second control signal line 19b, and the other end is connected to the first control signal line 19a via the backflow prevention diode _dj12 .
One end of the relay coil _Rj13 is connected to the third control signal line 19
c, and the other end is connected to a second control signal line 19b via a backflow prevention diode _dj13 . One end of the relay coil R _j14 is connected to the second control signal line 19b, and the other end is connected to the third control signal line 19c via the backflow prevention diode _dj14 . Each of the control signal lines 19a to 19c is connected to an individual relay E _j1 , F _{j1 to} E _j1.
j4 and F _j4 , the power supply terminal V _BB on the high potential side of the control circuit 7
And the ground GND on the low potential side. The relays E _j1 , F _{j1 to} E _j4 , F _j4 are independently controlled by relay control signals T _{j1 to} T _j4 from the control circuit 7. The relays E _j1 , F _{j1 to} E _j4 , F _j4 are included in the system interconnection inverter 9. The same applies to the later solar cell strings.

In the same manner as in FIG. 6, a photovoltaic power conversion device is constructed by further connecting in parallel a solar cell array 1 _j in which m solar cell strings S _j1 having the above configuration are connected in parallel. I have. Solar cell strings S _j1 ~
The configuration of the solar cell array 1 _j composed of the parallel connection of S _jm is basically the same as that of the third embodiment (FIG. 3). The connection configuration with the grid interconnection inverter 9 is basically the same as that of the third embodiment (FIG. 4).

[0043] Now, when you try to recover the light deterioration of the solar cell array _{1 1 ~1 n.} Light degradation recovery switch 1 manually
When 2 is turned on, sends a relay control signal R ₁ from the first solar cell array 1 ₁ control circuit 7 to the relay A _1, B ₁ linked in for the contact relay A _1, B _1, respectively Switch to b side. Then, the first solar cell array ₁₁ is in a reverse bias state. Next, the control circuit 7
Turn on the relay E _11, F ₁₁ by sending a relay control signal T ₁₁ for a greater relays E _11, F _11, first of all solar cell strings S ₁₁ to S _{1 m} of the first through m The relay coils R _{111 to} R _1m1 are connected to the power supply terminal V _{BB of the} control circuit 7.
And ground GND. A current from the power supply terminal V _BB passes through all the first relay coils R _{111 to} R _1m1 via the relay E ₁₁ and the control signal line 19a to excite the relay coils R _{111 to} R _1m1 , and the backflow prevention diode d via a control signal line 19b from ₁₁ to d _{1 m,} the result to flow to the ground GND via the relay F _11, the relay contact r ₁₁₁ ~r _1m1 connected in parallel to all of the first solar cell module M ₁₁₁ ~M _1m1 is turned off, the bypass diode D connected in series to the relay contact r ₁₁₁ ~r _{1m1
111 to} D _1m1 are the first solar cell modules M _{111 to} M
It will be separated from _1m1 . The control signal line 19a from the second solar cell module M ₁₁₂ ~M _{1 m @ 2}
Current is blocked by the presence of the backflow prevention diode d ₁₁₂ to d _{1 m @ 2} for. As a result, since all the first reverse bias voltage at the same time the solar cell module M ₁₁₁ ~M _1m1 is applied, the first light degradation of solar cell modules M ₁₁₁ ~M _1m1 all of which is recovered.

Next, the control circuit 7 outputs the relay control signal T ₁₁
By blocking with returning the relay contact r ₁₁₁ ~r _1m1 to the ON state by demagnetizing the relay coil R ₁₁₁ to R _1m1, sends the relay control signal T ₁₂ for the next relay E _12, F ₁₂ Te turn on the relay E _12, F _12, energizing all the second relay coil R ₁₁₂ to R _{1 m @ 2} by current flowing in the control signal line 19a from the control signal line 19b. Thereby, the second solar cell module M ₁₁₂
~M _{1 m @ 2} relay contact r ₁₁₂ ~r _{1 m @ 2} of the parallel connection is turned off, the bypass diode D ₁₁₂ to D _{1 m @ 2} is disconnected from the second solar cell module M ₁₁₂ ~M _{1 m @ 2,} all of the second solar cell module since the reverse bias voltage is applied to the M ₁₁₂ ~M _1m2, photodegradation of all these second solar cell module M ₁₁₂ ~M _{1 m @ 2} is restored.
The first solar battery module M ₁₁₁ backflow prevention for ~M _1m1 diode d from the control signal line 19b
The presence of ₁₁₁ to d _1m1 current is prevented, The third
The against the solar battery module M ₁₁₃ ~M _{1 m @ 3} current is prevented by the presence of the backflow prevention diode d ₁₁₃ to d _{1 m @ 3.} Then, the control circuit 7 causes return the relay contact r ₁₁₂ ~r _{1 m @ 2} to the ON state by blocking relay control signals T _12, and sends the relay control signal T ₁₃ for the next relay E _13, F ₁₃ By turning on the relays E ₁₃ and F ₁₃ and exciting all the third relay coils R _{113 to} R _1m3 by the current flowing from the control signal line 19c to the control signal line 19b, the relay contacts r _{113 to} r _1m3 are turned off. is in, since the bypass diode D ₁₁₃ to D _{1 m @ 3} is disconnected from the third solar battery module M ₁₁₃ ~M _{1 m @ 3,} a reverse bias voltage is applied to all of the third solar battery module _M 113 ~M _{1 m @ 3,} these All third
Of the photovoltaic modules M _{113 to} M _1m3 is recovered. Incidentally, for the control signal line 19c fourth solar cell modules _{M 114} ~M 1m4 current is prevented by the presence of the backflow prevention diode d ₁₁₄ ~d _1m4. Further, the control circuit 7 causes return the relay contact r ₁₁₃ ~r _{1 m @ 3} in the ON state by blocking relay control signals T _13,
Turn on the relay E _14, F ₁₄ by sending a relay control signal T ₁₄ for the next relay E _14, F _14, a control signal line 1
By energizing all of the fourth relay coil _{R 114} ~R 1m4 by a current flowing from 9b to the control signal line 19c, the relay contacts _{r 114} ~r 1m4 is turned off, the bypass diode _{D 114} ~D 1m4 fourth disconnected from the solar cell module _{M 114} ~M 1m4, since all of the fourth solar cell modules _{M 114} ~M 1m4 a reverse bias voltage is applied, all of these fourth solar cell modules _{M 114} ~M 1m4 Of light is recovered. The third solar cell from the control signal line 19b module M ₁₁₃
Blocking diode d ₁₁₃ for ~M _{1 m @ 3} to d _{1 m @ 3}
Current is blocked by the presence of. Thereafter, the returning the relay E _14, F ₁₄ to the ON state by blocking relay control signals T _14, to return the relay A ₁ pair to interrupt the relay control signals R _1, B ₁ to contact a respective . As described above, the recovery of photodegradation of the first solar cell array 1 ₁ of the solar battery module _{M 111 ~M 114 ... M 1m1 ~M} 1m4 is completed. Then performs sequentially photodegradation recovered in the same manner as described above for the second respective photovoltaic solar cell array 1 _second module _{M 211 ~M 214 ... M 2m1 ~M} 2m4. In the same manner, similar sequential photodeterioration recovery is performed for each solar cell module of each solar cell array, and finally, each of the solar cell modules M _{n11 to} M n of the n-th solar cell array 1 _n.
n14 ... For M _{nm1 to} M _nm4 , light deterioration recovery is sequentially performed in the same manner as described above. The operation of the calendar circuit 10 is the same as that of the first embodiment.

[Sixth Embodiment] In the sixth embodiment, only two control signal lines are provided in the distribution box. That is, as shown in FIG. 8, the two control signal lines 20a, 2
0b. FIG. 8 corresponds to one solar cell string S _j1 in the solar cell array 1 _j of FIG. String connectors 14a, 14b in distribution box 15
The control signal lines 20a and 20b are arranged between them. One end of the relay coil _Rj11 is connected to the first control signal line 20a, and the other end is a backflow prevention diode d.
It is connected to the second control signal line 20b via _j11 . One end of the relay coil R _j12 is connected to the second control signal line 20b, and the other end is a backflow prevention diode d _j12.
To the first control signal line 20a. One end of the relay coil _Rj13 is connected to the first control signal line 20a, and the other end is connected to the high-potential-side power supply output line 13a via an NPN-type switching transistor _Qj13.
It is connected to the. The first control signal line 20a and the second
The output terminal of the AND gate AND _j1 having two input terminals connected to the control signal line 20b is connected to the base of the switching transistor Q _j13 . Relay coil R
One end of _{j 14} is connected through a current limiting resistor R _j1 to the low-potential power supply output line 13b, the other end is connected to the high potential power supply output line 13a through the switching transistor Q _j14. The output terminal of the NOR gate NOR _j1 having two input terminals connected to the first control signal line 20a and the second control signal line 20b is connected to the switching transistor Q.
_{Connected to j14} base. Each control signal line 20
a, 20b is connected to a separate relay G _j1, H _j1 ~G _j4, the power supply terminal of the high-potential side of the control circuit 7 via the H _j4 V _BB and ground GND on the low potential side. The relays G _j1 , H _{j1 to} G _j4 , H _j4 are independently controlled by relay control signals T _{j1 to} T _j4 from the control circuit 7. The relays G _j1 , H _{j1 to} G _j4 , H _j4 are included in the system interconnection inverter 9. The same applies to the later solar cell strings.

In the same manner as in FIG. 6, a photovoltaic power conversion device is formed by further connecting in parallel a solar cell array 1 _j in which m solar cell strings S _j1 having the above configuration are connected in parallel. I have. Solar cell strings S _j1 ~
The configuration of the solar cell array 1 _j composed of the parallel connection of S _jm is basically the same as that of the third embodiment (FIG. 3). The connection configuration with the grid interconnection inverter 9 is basically the same as that of the third embodiment (FIG. 4).

Now, an attempt is made to recover the photodegradation of the solar cell arrays 1 ₁ to 1 _n . Light degradation recovery switch 1 manually
When 2 is turned on, sends a relay control signal R ₁ from the first solar cell array 1 ₁ control circuit 7 to the relay A _1, B ₁ linked in for the contact relay A _1, B _1, respectively Switch to b side. Then, the first solar cell array ₁₁ is in a reverse bias state. Next, the control circuit 7
Turn on the relay G _11, H ₁₁ by sending a relay control signal T ₁₁ more to the relay G _11, H _11, first of all solar cell strings S ₁₁ to S _{1 m} of the first through m The relay coils R _{111 to} R _1m1 are connected to the power supply terminal V _{BB of the} control circuit 7.
And ground GND. The current from the power supply terminal V _BB passes through all the first relay coils R _{111 to} R _1m1 via the relay G ₁₁ and the control signal line 20a to excite the relay coils R _{111 to} R _1m1 , and the backflow prevention diode d _{11 to} d _1m from control signal line 20b to relay H
Results flows to the ground GND via the _11, all of the first solar cell module M ₁₁₁ ~M _1m1 relay contact r ₁₁₁ ~r _1m1 of parallel connected is turned off, series with the relay contact r ₁₁₁ ~r _1m1 Connection bypass diode D ₁₁₁
To D _1m1 is to be disconnected from the first solar cell module M ₁₁₁ ~M _1m1. As a result, since all the first reverse bias voltage at the same time the solar cell module M ₁₁₁ ~M _1m1 is applied, the first light degradation of solar cell modules M ₁₁₁ ~M _1m1 all of which is recovered. Note that a backflow prevention diode d ₁₁₂ is connected from the control signal line 20a to the second solar cell modules M _{112 to} M _1m2 .
Current is blocked by the presence of to d _{1 m @ 2.} In addition, the AND gate AND ₁₁ ~AND _1m also NOR gate NOR ₁₁ ~NO
R _{1m is} also non-conductive and the switching transistor Q ₁₁₃
For _{~Q 1m3} ... Q ₁₁₄ ~Q 1m4 also non-conductive, the third relay coil R ₁₁₃ to R _{1 m @ 3,} a fourth relay coil R
_No current flows through _{114 to R1m4} .

Next, the control circuit 7 outputs the relay control signal T ₁₁
By blocking with returning the relay contact r ₁₁₁ ~r _1m1 to the ON state by demagnetizing the relay coil R ₁₁₁ to R _1m1, sends the relay control signal T ₁₂ for the next relay G _12, H ₁₂ Te turn on the relay G _12, H _12, energizing all the second relay coil R ₁₁₂ to R _{1 m @ 2} by current flowing in the control signal line 20a from the control signal line 20b. Thereby, the second solar cell module M ₁₁₂
~M _{1 m @ 2} relay contact r ₁₁₂ ~r _{1 m @ 2} of the parallel connection is turned off, the bypass diode D ₁₁₂ to D _{1 m @ 2} is disconnected from the second solar cell module M ₁₁₂ ~M _{1 m @ 2,} all of the second solar cell module since the reverse bias voltage is applied to the M ₁₁₂ ~M _1m2, photodegradation of all these second solar cell module M ₁₁₂ ~M _{1 m @ 2} is restored.
The first solar battery module M ₁₁₁ backflow prevention for ~M _1m1 diode d from the control signal line 20b
The presence of ₁₁₁ to d _1m1 current is prevented. In addition, the AND gate AND ₁₁ ~AND _1m also NOR gate NOR ₁₁ ~
The NOR _{1m is} also non-conductive and the switching transistor Q
₁₁₃ ~Q _1m3 ... Q ₁₁₄ for to Q _1M4 also non-conductive, the third relay coil R ₁₁₃ to R _{1 m @ 3,} no current flows through the fourth relay coil R ₁₁₄ ~R _1m4. Then, the control circuit 7 relay contacts r ₁₁₂ ~ blocks the relay control signal T ₁₂
r _1m2 is returned to the ON state, and the next relay G
_13, and sends the relay control signal T ₁₃ relative to H _13, both relays G ₁₃ which is connected to a power supply terminal V _BB, H ₁₃ was turned on, to conduct an AND gate AND ₁₁ ~AND _1m, the switching transistor Q ₁₁₃ to Q _{1 m @ 3} is turned on, by energizing all the third relay coil R ₁₁₃ to R _{1 m @ 3} by a current flowing from the control signal line 20a to the high-potential power supply output line 13a which is inverted to the low potential, relay contact r _{113 to} r _1m3 are turned off, and the bypass diodes D _{113 to} D _1m3 are connected to the third solar cell module M _113.
Disconnected from ~M _{1 m @ 3,} since all of the third solar battery module M ₁₁₃ ~M _{1 m @ 3} in the reverse bias voltage is applied, the third solar battery module M ₁₁₃ ~ all these
The photodegradation of M _1m3 is recovered. Incidentally, also, the NOR gate NOR ₁₁ ~NOR _1m is non-conductive, since the switching transistor _{Q 114} ~Q 1m4 is nonconductive, no current flows through the fourth relay coil R ₁₁₄ ~R _1m4. Further, the control circuit 7 causes return the relay contact r ₁₁₃ ~r _{1 m @ 3} in the ON state by blocking relay control signals T _13,
By sending a relay control signal T ₁₄ for the next relay G _14, H _14, to turn on the relay G _14, H _14, which are both connected to the ground GND, and the NOR gate NOR ₁₁ ~NOR _1m
Is conducting, the switching transistor _{Q 114} ~Q 1m4
It was turned on, all of the fourth through the current limiting resistor R ₁₁ to R _{1 m} by a current flowing from the low-potential power supply output line 13b which is inverted to the high potential to the high potential power supply output line 13a which is inverted to the low potential by energizing the relay coil R ₁₁₄ ~R _1m4, relay contacts _{r 114} ~r 1m4 is turned off, the bypass diode _{D 114} ~D 1m4 disconnected from the fourth solar cell modules M ₁₁₄ ~M _1m4, all since the reverse bias voltage to the fourth solar cell modules _{M 114} ~M 1m4 of is applied, photodegradation of all these fourth solar cell modules _{M 114} ~M 1m4 is restored. Incidentally, the AND gate AND ₁₁ ~AND _1m is non-conductive,
Since the switching transistor Q ₁₁₃ to Q _{1 m @ 3} is nonconductive, no current flows through the third relay coil R ₁₁₃ to R _{1 m @ 3.} Thereafter, the returning the relay G _14, H ₁₄ in the ON state by blocking relay control signals T _14, to return the relay A ₁ pair to interrupt the relay control signals R _111, B ₁ to contact a respective . As described above, the first solar cell array 1 ₁ of the solar battery module M ₁₁₁ ~M
₁₁₄ ... M _1m1 recovery of light deterioration of _~M 1m4 is completed. Then performs sequentially photodegradation recovered in the same manner as described above for the second respective photovoltaic solar cell array 1 _second module _{M 211 ~M 214 ... M 2m1 ~M} 1m4. In the same manner, similar sequential photodegradation recovery is performed on each solar cell module of each solar cell array, and finally, the n-th solar cell array 1
each of the solar battery module M of _{n n11} ~M _n14 ... M _nm1 ~M
_{As for nm4} , light degradation recovery is performed sequentially in the same manner as described above.
The operation of the calendar circuit 10 is the same as that of the first embodiment.

[Seventh Embodiment] A seventh embodiment relates to a modification of the sixth embodiment. An analog switch is used in place of a relay, and a 2-bit control signal is transmitted from a control circuit. Each analog switch is controlled. This will be described with reference to FIG. For each of the bypass diode _{D j11, D j12, D j13} , D j14, connect the switching transistors _{q j11, q j12, q j13} , q j14 instead of the relay contact, the base of the switching transistor q _j11, q _j12 each switching transistor qq _j11 to, be connected to one qq _j12, connects the output terminal of the aND gate the aND _j1 to the base of the switching transistor q _j13, NOR gate NOR _j1 to the base of the switching transistor q _j14
Output terminals are connected. Control signal lines 20a and 20b are connected to output ports P and Q of the control circuit 7, respectively. Output ports P and Q are (1, 0),
It can take four states, (0,1), (1,1), and (0,0).

When the output ports P and Q of the control circuit 7 are set to (1, 0) in a state where the relays A ₁ and B ₁ are switched to the contact b side, the switching transistor qq _j11 conducts,
Switching transistor q _j11 is blocked, the light deterioration recovery is performed on the first solar cell module M ₁₁₁ ~M _1m1. At this time, the switching transistor q _j12
Is non-conductive, AND gate AND _j1 and NOR gate NO
R _{j1 is} also non-conductive. _Assuming that the output ports P and Q are (0, 1), the switching transistor qq _j12 conducts,
Switching transistor q _j12 is blocked, the light deterioration recovery is performed for the second solar cell module M ₁₁₂ ~M _1m2. At this time, the switching transistor q _j11
Is non-conductive, AND gate AND _j1 and NOR gate NO
R _{j1 is} also non-conductive. _Assuming that the output ports P and Q are (1, 1), the AND gate AND _j1 is turned on, the switching transistor q _j13 is turned off, and the light deterioration recovery is performed on the third solar cell modules M _{113 to} M _1m3 . . At this time, the switching transistors q _j11 and q _j12 are non-conductive, and the NOR gate NOR _j1 is also non-conductive. Output port P, when the Q (0, 0), conducts the NOR gate NOR _j1, switching transistors q _j14 is blocked, the light deterioration recovery is performed on the fourth solar cell modules _{M 114} ~M 1m4. At this time, the switching transistors q _j11 and q _j12 are non-conductive, and the AND gate AND _j1 is also non-conductive.

[Eighth Embodiment] An eighth embodiment relates to a modification of the sixth embodiment, in which the photovoltaic modules of two solar cells are recovered from light deterioration. FIG.
It will be described based on. While switching the relay A _1, B ₁ to the contact b side, and turns on the relay K _11, L ₁₁ and sends the relay control signal T ₁₁ from the control circuit 7, all of the solar cell of the first through m strings S ₁₁ to S first energized relay coil R ₁₁₁ a to R _1m1 and a second relay coil R ₁₁₂ to R _{1 m @ 2} at the same time _{1 m,} the relay contact r ₁₁₁ ~r
_1m1, r ₁₁₂ ~r _1m2 is turned off at the same time, the bypass diode _{D 111 ~D 1m1, D 112 ~D} 1m2 first and second solar cell modules M ₁₁₁ ~M _1m1, M ₁₁₂ ~M
It will be separated from _1m2 . As a result, all of the first and second solar cell modules M ₁₁₁ ~M _1m1,
Light deterioration recovery of the M ₁₁₂ ~M _1m2 is performed. Then, the control circuit 7 relay K ₁₂ by sending a relay control signal T ₁₂ from,
The L ₁₂ is turned on, the third relay coil R ₁₁₃ of all of the solar cell strings S ₁₁ to S _{1 m} of the first through m ~
Simultaneously exciting the R _{1 m @ 3} and a fourth relay coil _{R 114} ~R 1m4, relay contact _{r 113 ~r 1m3, r 114 ~r} 1m4
Are simultaneously turned off, and the bypass diodes D _{113 to} D _113
1m3, D ₁₁₄ ~D _1m4 the first solar battery module M
Becomes ₁₁₃ ~M _1m3, M ₁₁₄ be disconnected from _~M 1m4. As a result, all of the third and fourth solar cell modules M ₁₁₃ ~M _{1 m @ 3,} photodegradation recovery _{M 114} ~M 1m4 is performed. The configuration of the relay has been simplified.

Ninth Embodiment A ninth embodiment relates to a modification of the eighth embodiment. In the case where two photovoltaic modules are subjected to photodegradation recovery, the high-potential power supply inverted to a low potential is used. The control current flows through the output line 13a. A description will be given based on FIG. While switching the relay A _1, B ₁ to the contact b side, and turns on the relay K ₁₁ by sending a relay control signal T ₁₁ from the control circuit 7, a control signal current from a power supply terminal V _BB of the control circuit 7 by passing from the line 20a to the high-potential power supply output line 13a which is inverted to the low potential, the first relay coil R ₁₁₁ to R _1m1 of all solar cell strings S ₁₁ to S _{1 m} of the first through m and Second relay coil R
_{112 to} R _1m2 are simultaneously excited and relay contacts r _{111 to} r _1m1
, R ₁₁₂ ~r _{1 m @ 2} is turned off at the same time, the bypass diode _{D 111 ~D 1m1, D 112 ~D} 1m2 will be disconnected from the first solar cell module _{M 111 ~M 1m1, M 112 ~M} 1m2. As a result, all of the first and second solar cell modules M ₁₁₁ ~M _1m1, M ₁₁₂ ~M
_1m2 light degradation recovery is performed. Then, turn on the relay K ₁₂ by sending a relay control signal T ₁₂ from the control circuit 7,
By passing a current from the power supply terminal V _BB of the control circuit 7 from the control signal line 20b to the high-potential power supply output line 13a which is inverted to the low potential, and all of the solar cell strings S ₁₁ ~ of the first through m S _1m third relay coils R _{113 to} R _1m3 and fourth relay coils R _{114 to} R ₁₁₄
At the same time exciting the _1m4, relay contact r ₁₁₃ ~r _1m3, r
₁₁₄ ~r _1m4 is turned off at the same time, the bypass diode _{D 113 ~D 1m3, D 114 ~D} 1m4 will be disconnected from the first solar cell module _{M 113 ~M 1m3, M 114 ~M} 1m4. As a result, all of the third and fourth solar cell modules M ₁₁₃ ~M _{1 m @ 3,} photodegradation recovery _{M 114} ~M 1m4 is performed. The configuration of the relay has been further simplified.

[Embodiment 10] Embodiment 10 relates to a modification of Embodiment 6, in which all four solar cell modules recover from light degradation simultaneously. This will be described with reference to FIG. While switching the relay A _1, B ₁ to the contact b side, and turns on the relay K _11, L ₁₁ and sends the relay control signal T ₁₁ from the control circuit 7, all of the solar cell of the first through m Strings S ₁₁ ~
The first relay coil R ₁₁₁ to R _1m1 of S _{1 m,} the second relay coil R ₁₁₂ to R _{1 m @ 2,} a third relay coil R ₁₁₃ ~
Simultaneously exciting the R _{1 m @ 3} and a fourth relay coil _{R 114} ~R 1m4, relay contact r ₁₁₁ ~r _1m1, r ₁₁₂ ~r
_{1m2, r 113 ~r 1m3, r} 114 ~r 1m4 is turned off at the same time, the bypass diode D ₁₁₁ ~D _1m1, D ₁₁₂ ~D
_{1m2, D 113 ~D 1m3, D} 114 ~D 1m4 fourth from the first
Solar cell modules M _{111 to} M _1m1 , M _{112 to} M
_{1m2, M 113 ~M 1m3, M} 114 will be disconnected from _~M 1m4. As a result, the solar cell module M ₁₁₁ from all of the first to third _{4 ~M 1m1, M 112 ~M 1m2} ,
Photodegradation recovery _{M 113 ~M 1m3, M 114 ~M} 1m4 are performed simultaneously. The configuration of the relay has been simplified.

[Eleventh Embodiment] An eleventh embodiment relates to a modification of the tenth embodiment, in which only one control signal line is used, and all four solar cell modules simultaneously recover from light deterioration. Things. This will be described with reference to FIG. While switching the relay A _1, B ₁ to the contact b side, and turns on the relay K ₁₁ by sending a relay control signal T ₁₁ from the control circuit 7, the power supply terminal V _BB of the control circuit 7
From the control signal line 20a to the high potential side power supply output line 13a inverted to a low potential,
All the first to m-th solar cell strings S ₁₁
ＳS _1m, a first relay coil R ₁₁₁ ＲR _1m1 , a second relay coil R ₁₁₂ ＲR _1m2 , a third relay coil R ₁₁₃
The to R _{1 m @ 3} and a fourth relay coil _{R 114} ~R 1m4 simultaneously excited, the relay contact r ₁₁₁ ~r _1m1, r ₁₁₂ ~r
_{1m2, r 113 ~r 1m3, r} 114 ~r 1m4 is turned off at the same time, the bypass diode D ₁₁₁ ~D _1m1, D ₁₁₂ ~D
_{1m2, D 113 ~D 1m3, D} 114 ~D 1m4 fourth from the first
Solar cell modules M _{111 to} M _1m1 , M _{112 to} M
_{1m2, M 113 ~M 1m3, M} 114 will be disconnected from _~M 1m4. As a result, the solar cell module M ₁₁₁ from all of the first to third _{4 ~M 1m1, M 112 ~M 1m2} ,
Photodegradation recovery _{M 113 ~M 1m3, M 114 ~M} 1m4 are performed simultaneously. The configuration of the control signal line and the relay is simplified.

[Twelfth Embodiment] The twelfth embodiment also has only two control signal lines in the distribution box. That is, as shown in FIG. 14, the two control signal lines 20 wired in the distribution box 15
a and 20b. FIG. 14 shows the solar cell array 1 _j of FIG.
Corresponds to one solar cell string S _j1 . Strings connector 14 in distribution box 15
control signal lines 20a, 20b
Are wired. Each control signal lines 20a, 20b are connected to a separate relay U _j1, V _j1 ~U _j4, the power supply terminal of the high-potential side of the control circuit 7 via a V _j4 V _BB and ground GND on the low potential side. Further, each relay U _j1 , V _j1 .
U _j4 and V _j4 are relay control signals T _{j1 to} T _j from the control circuit 7.
It is controlled independently by _j4 . The relays U _j1 , V _{j1 to} U _j4 , V _j4 are included in the system interconnection inverter 9. In the power distribution box 15, a backflow prevention diode _dj11 is inserted between one end of the relay coil _Rj11 and the low-potential-side power output line 13b, and between the low-potential-side power output line 13b and one end of the relay coil _Rj12. A backflow prevention diode _dj12 is inserted into the relay coil R
blocking diode d _j13 between one end and the low-potential power supply output line 13b of the _j13 is inserted, the backflow prevention diode d _j14 between one end of the low-potential power supply output line 13b and the relay coil R _j14 is inserted ing. The same applies to the later solar cell strings.

[0056] Now, when you try to recover the light deterioration of the solar cell array _{1 1 ~1 n.} When the calendar circuit 10 operates, the control circuit 7 starts the following processing. FIG. 15 is a timing chart for the relay, and FIG. 16 is a relay operation sequence. First sent from linked relay A _1, the control circuit 7 with respect to B ₁ of the solar cell array 1 ₁ relay control signals R _1, it switches the relay A _1, B ₁ each contact b. Then, the first solar cell array ₁₁ is in a reverse bias state. Next, the control circuit 7 sends a relay control signal T ₁₁ to the relays U ₁₁ and V ₁₁ .
And all the first relay coils R _{111 to} R _1m1
Was turned on, the relay contact r ₁₁₁ ~r _1m1 is turned off,
The bypass diode D ₁₁₁ to D _1m1 disconnected from the first solar cell module M ₁₁₁ ~M _1m1, all of the first
Light degradation is restored by a reverse bias voltage at the same time the solar cell module M ₁₁₁ ~M _1m1 of application. Then relay U
_12, and sends the relay control signal T ₁₂ relative to V _12, the same way all the second solar cell module M ₁₁₂ ~M _{1 m @ 2}
At the same time, a reverse bias voltage is applied to recover light degradation. Further, a relay control signal T is applied to the relays U ₁₃ and V ₁₃ .
₁₃ is sent out, and a reverse bias voltage is simultaneously applied to all the third solar cell modules M _{113 to} M _1m3 in the same manner to recover light degradation. Also sends a relay control signal T ₁₄ to the relay U _14, V _14, similarly to all of the fourth solar cell modules _{M 114} ~M 1m4 photodegradation reverse bias voltage is applied simultaneously is restored . As described above, the solar cell module M of the _first solar cell array 11
₁₁₁ ~M ₁₁₄ ... M _1m1 ~M recovery of light deterioration of _1m4 is completed. Then performs sequentially photodegradation recovered in the same manner as described above for the second respective photovoltaic solar cell array 1 _second module _{M 211 ~M 214 ... M 2m1 ~M} 1m4. The same sequential photodegradation recovery against in the same manner the solar cell modules of each solar cell array, and finally, the solar battery module M of a solar array 1 _n of the n _n11 ~M _n14 ... M
Light degradation recovery is sequentially _performed for _{nm1 to Mnm4 in the same} manner as described above. Instead of the operation by the calendar circuit 10, the light deterioration recovery switch 12 is manually turned on in a timely manner,
Light deterioration recovery may be performed.

In any of the above, the reverse bias voltage is generated by another solar cell array group. For example, FIG. 17A shows an I (current) -V (voltage) characteristic of a solar cell array for generating a reverse bias voltage, and FIG. 17 shows an IV characteristic of a solar cell array to which a reverse bias can be applied.
When these are connected as the curve of (b), FIG.
The solar cell array (a), the position of the current value of the short circuit current value Im ₂ of the solar cell array shown in FIG. 17 (b) is an operating point, the voltage at that time is the V _B of FIG. 17 (a). Then, this voltage is applied as a reverse bias to the solar cell array of FIG. 17B, thereby recovering from light degradation. At this time, short-circuit current Im ₃ of the solar cell array for reverse bias generation as is apparent from FIG. 17, must be connected to be larger than the short-circuit current Im ₂ reverse bias application target of the solar array.

In each of the above embodiments, the reverse bias voltage uses a DC voltage generated by another solar cell array group through photovoltaic power generation. However, the present invention is not limited to this. DC- input from the inverter main circuit 6
A DC converter may be configured, and the output voltage of the DC-DC converter may be used as a reverse bias voltage.

[0059]

According to the first aspect of the present invention, even in a photovoltaic power conversion device in which a bypass diode is connected in parallel to a solar cell module, a current due to a reverse bias voltage is applied to the solar cell module. Avoiding a state in which the photovoltaic module is bypassed, the reverse bias voltage is reliably applied, and the photodegradation of the photovoltaic module to the almost initial state can be satisfactorily recovered, thereby improving the system efficiency of the photovoltaic power generation system. .

According to the second aspect of the present invention, the above-described function is exerted by a relatively simple structure of opening and closing means, and maintenance work is reduced.

According to the third aspect of the invention, the reverse bias voltage can be covered by the electric power generated by the photovoltaic power generation in the state where the solar light is irradiated, and the cost for recovering from the photodegradation can be reduced.

The invention according to claim 4 is suitable for a power conversion device for photovoltaic power generation using an amorphous silicon thin film solar cell which is liable to photodegradation.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a power converter for photovoltaic power generation according to a first embodiment of the present invention.

FIG. 2 is a circuit configuration diagram of a solar cell array according to Embodiment 2 of the present invention.

FIG. 3 is a circuit configuration diagram of a solar cell array according to Embodiment 3 of the present invention.

FIG. 4 is a circuit configuration diagram of a photovoltaic power conversion device according to a third embodiment in which the solar cell arrays of FIG. 3 are connected in parallel.

FIG. 5 is a circuit configuration diagram of a solar cell array according to Embodiment 4 of the present invention.

FIG. 6 is a circuit configuration diagram of a photovoltaic power conversion device according to a fourth embodiment in which the solar cell arrays of FIG. 5 are connected in parallel.

FIG. 7 is a circuit configuration diagram of a solar cell string according to a fifth embodiment of the present invention.

FIG. 8 is a circuit configuration diagram of a solar cell string according to a sixth embodiment of the present invention.

FIG. 9 is a circuit configuration diagram of a solar cell string according to a seventh embodiment of the present invention.

FIG. 10 is a circuit configuration diagram of a solar cell string according to Embodiment 8 of the present invention.

FIG. 11 is a circuit diagram of a solar cell string according to a ninth embodiment of the present invention.

FIG. 12 is a circuit configuration diagram of a solar cell string according to Embodiment 10 of the present invention.

FIG. 13 is a circuit configuration diagram of a solar cell string according to Embodiment 11 of the present invention.

FIG. 14 is a circuit configuration diagram of a solar cell string according to Embodiment 12 of the present invention.

FIG. 15 is a timing chart of a relay in the power converter for photovoltaic power generation of the twelfth embodiment.

FIG. 16 shows a relay operation sequence in the photovoltaic power converter according to the twelfth embodiment.

FIG. 17 is a current-voltage characteristic diagram of a solar cell array according to each embodiment.

FIG. 18 is a circuit configuration diagram of a power conversion device for photovoltaic power generation of the prior art devised to recover light degradation of a solar cell by applying a reverse bias voltage.

FIG. 19 is a circuit configuration diagram in which a bypass diode is connected in parallel to a solar cell module.

FIG. 20 is a configuration diagram of a conventional residential solar cell system.

[Explanation of symbols]

1 _j ... solar cell array, 2 _j1 ... high potential side output terminal, 2 _j2 ... low potential side output terminal, 3 _j ... backflow prevention diode, 5 ... commercial system, 6 ... inverter main circuit ,
6a... High potential side power input line, 6b... Low potential side power input line, 7... Control circuit, 9. ... Low-potential-side power supply line, 12... Light-degradation recovery switch, 13 a... High-potential-side power supply output line, 13 b.
b ... Strings connector, 15 ... Distribution box,
16a to 16d: Module connector, 17a to 17
d: control signal line, 18a: high potential side power output line, 18b: low potential side power output line, 19a to 1
9c: control signal line, 20a, 20b: control signal line, AND _ji : AND gate, A _j: relay
B _j ... relay, C _ji ... relay, D _ji ... bypass diode, DD _ji ... backflow prevention diode, d _ji ... backflow prevention diode, E _ji ... relay, F _ji ... relay,
G _ji ... relay, H _ji ... relay, K _ji ... relay, L
_ji …… Relay, M _ji …… Solar cell module, NOR _ji
…… Nor gate, Q _ji … Switching transistor,
q _ji ...... switching transistor, qq _ji ...... switching transistor, R _ji ...... relay coil, r _ji ......
Relay contact, R _j ... relay control signal, S ... reverse bias application command, S _ji ... solar cell strings, T _ji ...
Relay control signal, _Uji ... relay, _Vji ... relay, V
_BB ...... Power supply terminal

Claims (4)

[Claims] 1. A photovoltaic power converter for applying a reverse bias voltage to a solar cell module to recover light degradation, wherein a bypass diode is connected in parallel to the solar cell module, A photovoltaic power conversion device configured to disconnect a bypass diode when a voltage is applied. 2. The power converter for photovoltaic power generation according to claim 1, wherein switching means is inserted in series with the bypass diode, and the switching means is opened when a reverse bias voltage is applied. 3. The solar battery module according to claim 1, wherein the remaining solar battery module uses the photovoltaic power generated as the reverse bias voltage for the solar battery module to be subjected to light degradation recovery. Power converter for solar power generation. 4. The power converter for photovoltaic power generation according to claim 1, wherein the solar cell module is an amorphous silicon thin film solar cell.