JP6792820B2 - Solar power system - Google Patents

Description

The present invention relates to a photovoltaic power generation system in which DC power output from a solar cell group is converted into predetermined AC power by a chopper unit and an inverter and connected to a power system.

As a prior art of this kind of photovoltaic power generation system, the one described in Patent Document 1 is known.
FIG. 5 is a block diagram showing a schematic configuration of this prior art, and the photovoltaic power generation system includes solar cell groups 2a and 2b, chopper units 3a and 3b, an inverter 4, and a capacitor 5. The chopper units 3a and 3b are provided with the first operating point control means 6a and 6b, respectively, and the inverter 4 is provided with the second operating point control means 8.

Chopper unit 3a, 3b, respectively boosts solar cell groups 2a, the DC output voltage of 2b as an input voltage _{V in,} and output.
Since the inverter 4 operates in interconnection with a power system (not shown), voltage adjustment and synchronous adjustment are performed, and the DC voltage output from the chopper units 3a and 3b is converted into an AC voltage and output. The AC voltage output from the inverter 4 is transformed into the system voltage at each site by a transformer (not shown).
The inverter 4, as the input voltage E is constant or predetermined voltage range, has a function of controlling the AC output current I _o.

The first operating point control means 6a and 6b in the chopper units 3a and 3b optimize the operating points of the solar cell groups 2a and 2b by controlling the input current I _in , and from the solar cell groups 2a and 2b, respectively. Maximum power point tracking (MPPT) control is performed so as to obtain the maximum output.

Further, the chopper unit 3a, 3b, when the input voltage V _in exceeds a predetermined input voltage of the inverter 4, the switching operation is stopped function of outputting directly the input voltage V _in as the voltage E (through mode operation Function). This through mode operation function plays a role of preventing the occurrence of switching loss in the chopper units 3a and 3b, and this function makes it possible to improve the efficiency of the photovoltaic power generation system.

FIG. 6 is a schematic configuration diagram showing the main circuits (both units are the same) of the chopper units 3a and 3b.
That is, the chopper unit 3a, the main circuit of 3b includes a DC input terminals _P 1, _N semiconductor switching elements connected in series between ₁ (MOSFET) 31 and inductor 32, a free wheeling diode 33, a switching diode 34 , A chopper 36 including a capacitor 35, and a short-circuit means 7. Note that P ₂ and N ₂ are DC output terminals.

The short-circuit means 7 comprises either a low-frequency rectifier diode, a mechanical contact switch, or a synchronous rectifier circuit using a semiconductor switching element, or a combination thereof. The short-circuiting means 7, during the through mode operation described above, the chopper unit 3a, and short circuit between input and output terminals _P 1, _{P 2} of 3b, and outputs the input voltage _{V in} as it voltage E.

Further, the second operating point control means 8 in the inverter 4 has a function of changing the input voltage E to optimize the operating points of the solar cell groups 2a and 2b, and all the chopper units 3a and 3b pass through. When the mode operation is performed, the maximum power tracking control for changing the operating point is performed so that the total output power of the solar cell groups 2a and 2b is maximized.

In the conventional technique configured as described above, even when the output voltage of the solar cell groups 2a and 2b is small, the input voltage is boosted by the chopper units 3a and 3b to increase the input voltage E of the inverter 4. Can be done. Therefore, the AC output voltage of the inverter 4 can be set high, the output current _Io of the inverter 4 can be reduced for the same output power, the conduction loss in the inverter 4 can be reduced, and the device can be miniaturized. is there.

Furthermore, the output power of the solar cell groups 2a and 2b can be maximized by performing MPPT control by the chopper units 3a and 3b provided corresponding to the solar cell groups 2a and 2b, respectively, so that all the solar cell groups can be used. Compared with the case where MPPT control is performed collectively for 2a and 2b, there is an advantage that the output power of the entire photovoltaic power generation system can be increased.

Next, an example of the operation of this photovoltaic power generation system will be described.
For example, as a result of one of the chopper unit 3a has performed MPPT control, when the output voltage V _in of the solar cell group 2a exceeds a predetermined input voltage of the inverter 4, switching loss by stopping switching operation of the chopper unit 3a together with reducing, and outputs the output terminal P _1, P ₂ between shorting the input voltage V _in of the chopper unit 3a by short-circuiting means 7 as it is as the voltage E (through mode operation).

At this time, as a result of the other chopper unit 3b has performed MPPT control, the output voltage V _in of the solar cell group 2b is less than the predetermined input voltage of the inverter 4, the chopper unit 3b is boosting operation performed switching.
As described above, according to the prior art, it is possible to increase the output power of the solar cell groups 2a and 2b, reduce the loss, and increase the output power of the photovoltaic power generation system.

Japanese Patent No. 5880778 (paragraphs [0021] to [0031], FIG. 1, etc.)

By the way, the DC power obtained from the solar cell group fluctuates with changes in the amount of solar radiation and temperature.
In the photovoltaic power generation system shown in FIG. 5, when the amount of solar radiation suddenly increases, the output powers of these are rapidly increased by the chopper units 3a and 3b performing MPPT control. Inverter 4, as the input voltage E is constant, or by controlling the AC output current I _o to a predetermined voltage range, the output effective power of the inverter 4 is rapidly increased as a result.

However, in a fragile power system such as a remote island, the frequency of the system fluctuates when the output active power of the inverter 4 increases rapidly.
Therefore, while the conventional photovoltaic power generation system has the above-mentioned advantages, there is a problem that the frequency of the system fluctuates when the amount of solar radiation suddenly increases, which adversely affects the load, especially in a fragile power system such as a remote island. was there.

Therefore, an object of the present invention is to provide a photovoltaic power generation system capable of reducing fluctuations in the system frequency at the time of a rapid increase in the amount of solar radiation and contributing to stabilization of the electric power system.

In order to solve the above problems, the invention according to claim 1 is installed corresponding to a plurality of solar cell groups, and the DC output voltage of the solar cell group is set to a predetermined magnitude by the operation of the semiconductor switching element. Multiple chopper units that convert to DC voltage,
An inverter that is commonly connected to the output side of the plurality of chopper units and that converts DC voltage to AC voltage by the operation of semiconductor switching elements and operates in interconnection with the power system.
A first operating point for maximizing the output power of the solar cell group by controlling the output current of the chopper unit and optimizing the operating point of the solar cell group connected to the chopper unit. Control means and
When the output voltage of the solar cell group exceeds a predetermined input voltage of the inverter, the switching operation of the chopper unit is stopped and the through mode operation of directly outputting the output voltage of the solar cell group to the inverter is executed. Function and
By controlling the input voltage of the inverter and optimizing the operating points of all the solar cell groups when all the chopper units operate in the through mode, the total output power of all the solar cell groups is maximized. A second operating point control means for converting to
In a photovoltaic power generation system equipped with
A first change rate limiting means that limits the rate of change in the increasing direction of the input power of the chopper unit in which the first operating point control means is operating so as not to exceed a predetermined value .
When the second operating point control means is operated, the second change rate limiting means for limiting the rate of change in the increasing direction of the input power of the inverter so as not to exceed a predetermined value ,
When the rate of change in the increasing direction of the input power of the inverter exceeds a predetermined value when the second rate of change limiting means does not operate, the power rapid increase suppressing means for suppressing the increase in the input power of the inverter
It is characterized by being equipped with.

The invention according to claim 2 is the photovoltaic power generation system according to claim 1.
The first rate of change limiting means is
A means for generating a chopper input power command based on the chopper input voltage and the chopper input voltage command obtained by the first operating point control means, and
A means for generating a chopper input current command so that the rate of change in the increasing direction of the chopper input power command does not exceed a predetermined rate of change in the increasing direction, and
A means for generating an on / off command for the switching element of the chopper unit so that the deviation between the chopper input current command and the chopper input current becomes zero, and
It is characterized by being equipped with.

The invention according to claim 3 is the photovoltaic power generation system according to claim 1 or 2.
The second rate of change limiting means is
A means for generating a first effective current command so that the deviation between the inverter input voltage and the inverter input voltage command obtained by the second operating point control means becomes zero.
A means for generating the second effective current command by limiting the rate of change in the increasing direction of the first effective current command so as not to exceed a predetermined value.
A means for generating an inverter output voltage command using the second effective current command, an invalid current command, and an inverter output current, and generating an on / off command for the switching element of the inverter based on the inverter output voltage command.
It is characterized by being equipped with.

The invention according to claim 4 is the photovoltaic power generation system according to any one of claims 1 to 3.
The power rapid increase suppressing means is
When the rate of change in the increasing direction of the input power of the inverter exceeds a predetermined rapid increase detection level, the previously calculated value of the effective current command of the inverter is set to the upper limit value, and the upper limit of the effective current command is changed to the previously calculated value. A means for generating an effective current command with the value obtained by sequentially adding the amount addition values as a new upper limit value,
A means for generating an inverter output voltage command using the effective current command, an invalid current command, and an inverter output current, and generating an on / off command for the switching element of the inverter based on the inverter output voltage command.
It is characterized by being equipped with.

According to the fifth aspect of the present invention, in the photovoltaic power generation system according to any one of claims 1 to 4, the first operating point control means and the first rate of change limiting means are installed in the chopper unit. In addition to being provided, the inverter is provided with the second operating point control means, the second rate of change limiting means, and the power rapid increase suppressing means.

According to the present invention, while aiming to increase the output power and reduce the loss of the solar cell group, it suppresses the rapid increase in the active power output from the inverter even when the amount of solar radiation suddenly increases, and adversely affects the frequency fluctuation and the load of the system. Can be suppressed. This makes it possible to realize a highly efficient and high-performance photovoltaic power generation system.

It is a block diagram which shows the schematic structure of embodiment of this invention. It is a control block diagram for demonstrating the operation of the chopper power increase direction change rate limiting means in FIG. It is a control block diagram for demonstrating the operation of the inverter power increase direction change rate limiting means in FIG. It is a control block diagram for demonstrating the operation of the inverter power rapid increase suppressing means in FIG. It is a block diagram which shows the schematic structure of the prior art described in Patent Document 1. It is a schematic block diagram which shows the main circuit of the chopper unit in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of this embodiment. In FIG. 1, parts having the same functions as those shown in FIG. 5 are designated by the same reference numerals and description thereof will be omitted. Hereinafter, parts different from those in FIG. 5 will be mainly described.

The embodiment shown in FIG. 1 differs from that of FIG. 5 in that the chopper units 30a and 30b are provided with chopper power increasing direction change rate limiting means 21a and 21b in addition to the first operating point control means 6a and 6b, respectively. In addition to the second operating point control means 8, the inverter 40 includes an inverter power increase direction change rate limiting means 22 and an inverter power rapid increase suppressing means 23.
The configurations of the chopper units 30a and 30b are the same, and the main circuit thereof includes a chopper 36 and a short-circuiting means 7 as in FIG. 6 described above.

First, the chopper power increasing direction change rate limiting means 21a and 21b operate when the chopper units 30a and 30b perform MPPT control, respectively.
Further, the inverter power increasing direction change rate limiting means 22 operates when all the chopper units 30a and 30b operate in the through mode and the inverter 40 performs MPPT control. Further, the inverter power rapid increase suppressing means 23 operates when the inverter 40 does not perform MPPT control, that is, when a chopper unit that performs MPPT control is partially present.

Next, the configuration and operation of the chopper power increasing direction change rate limiting means 21a and 21b will be described with reference to FIG. Since the configurations of the limiting means 21a and 21b are the same, here, the chopper power increasing direction change rate limiting means 21a in the chopper unit 30a will be described as an example.

If chopper unit 30a performs MPPT control, as shown in FIG. 2 obtains the input power _{P in} and multiplied by a chopper input current _{I in} and the chopper input voltage _{V in} and a multiplication means 301, the input power _{P in} operating point control means 6a in response to performs MPPT control, determine the input voltage command _{V in} ^*. Determined by the input voltage command _{V in} ^* a chopper input voltage _{V in} and deviation subtraction means 302, the input current command (before power change ratio _limitation) by the voltage regulator 303 so that the deviation becomes zero _I ^{in **} Is obtained and input to the chopper power increasing direction change rate limiting means 21a.

In the chopper power increasing direction change rate restriction means 21a, the input current command by multiplying means 211 (before power change ratio limitation) by multiplying the I _in ^** the chopper input voltage V _in, input power command (before power change ratio limitation) Find _Pin ^** . To the input power command (before power change rate limit) P _in ^**, through the increasing direction change rate limiter 212 obtains the input power command P _in ^* after power change rate limit, the chopper input voltage V by multiplying means 214 by multiplying the _in reciprocal of (1 _{/ V in)} obtaining the input current command _{I in} ^* after power change rate limit.
Here, the command holding means 213 holds the last calculated value of the input power command P _in ^*, increasing direction change rate limiter 212, the direction of increasing the current calculated value for the previously calculated value of the input power command P _in ^* It operates so that the rate of change does not exceed a predetermined value.

Next, the deviation between the input current command I _in ^* output from the multiplication means 214 and the chopper input current I _in is obtained by the subtraction means 215, and the voltage with respect to the switching control means 304 is obtained by the current regulator 216 so that this deviation becomes zero. Generate a command. The switching control means 304 outputs an on / off command to the switching element 31 (see FIG. 6) of the chopper 36 based on the voltage command, and controls the operation of the chopper 36.

By the above operation, the rate of change of the solar cell group 2a in which the chopper unit 30a controls MPPT can be limited when the amount of solar radiation rapidly increases and the output power increases.
If the amount of solar radiation suddenly decreases and the output power of the solar cell group 2a suddenly decreases, the rate of change cannot be limited to the specified range, so the rate of change in the direction of decrease in output power should not be limited. To do.
The above-mentioned operation is the same for the chopper power increasing direction change rate limiting means 21b in the other chopper unit 30b.

Next, the operation of the inverter power increasing direction change rate limiting means 22 in the inverter 40 will be described with reference to FIG.
When all the chopper units 30a and 30b operate in through mode and the inverter 40 performs MPPT control, the input current of the inverter 40 (the total value of the output currents of the solar cell groups 2a and 2b) as shown in FIG. I _d and the input voltage E are multiplied by the multiplying means 401 to obtain the input power _{Pin INV} , and the operating point control means 8 performs MPPT control according to the input power _{Pin INV} to obtain the input voltage command E ^* .

Next, the deviation between the input voltage command E ^* and the inverter input voltage E is obtained by the subtracting means 402, and the effective current command (before the rate of change limitation) _IP ^** is issued by the voltage regulator 403 so that the deviation becomes zero. It is obtained and input to the inverter power increasing direction change rate limiting means 22.
For this effective current command (before the rate of change limitation) I _P ^** , the effective current command I _P ^* after the rate of change is limited is obtained via the increase direction change rate limiter 221, and this effective current command I _P ^* is adjusted. Input to the device 223. Here, the command holding means 222 holds the previously calculated value of the effective current command _IP ^* , and the increase direction change rate limiter 221 is the increasing direction of the current calculated value with respect to the previously calculated value of the effective current command _IP ^*. It operates so that the rate of change does not exceed a predetermined value.

The current controller 223 generates a voltage command so that the deviations between the active current command _IP ^* and the reactive current command _IQ ^* and the active current component and the reactive current component in the inverter output current _Io become zero. Then, it is output to the addition means 407. Incidentally, PLL circuit 405 is for generating a phase reference signal from the inverter output voltage _{V o.}

The addition means 407, compensation signal is also inputted obtained by entering the inverter output voltage V _o to the counter voltage compensation means 406. Here, the counter voltage compensation means 406, in order to output the same voltage as the electric power system to interconnection inverter 40, the inverter output voltage V _o, a band pass filter operation and detection delay for the purpose of ripple removal The compensation signal is generated by performing phase lead correction for correction and performing calculations for soft-starting the output voltage.
The switching control means 404 controls the operation of the inverter 40 by generating an on / off command for the switching element of the inverter 40 based on the voltage command after the counter voltage compensation.

By the above operation, when all the chopper units 30a and 30b operate in the through mode and the inverter 40 performs MPPT control, the output power generated by the solar cell groups 2a and 2b is controlled by controlling the effective current output by the inverter 40. It is possible to limit the rate of change in the increasing direction of.
If the amount of solar radiation suddenly decreases and the output power of the solar cell groups 2a and 2b suddenly decreases, the rate of change cannot be limited to the specified range, so the rate of change in the direction of decrease in output power is not limited. I will do it.

Next, the operation of the inverter power rapid increase suppressing means 23 will be described with reference to FIG.
When the chopper unit that performs MPPT control and the chopper unit that operates in the through mode coexist, the chopper unit that operates in the through mode cannot control the output power of the solar cell group connected to the chopper unit. In other words, if the operating point control means 8 in the inverter 40 does not operate and the inverter power increase direction change rate limiting means 22 does not operate, the output power of the solar cell group cannot be controlled.
Therefore, the inverter power rapid increase suppressing means 23 is for suppressing the rapid increase in the output power of the solar cell group at the time of the rapid increase in the amount of solar radiation in such a case.

4, obtains an inverter input power _{P InINV} by multiplying by the inverter input voltage E of the inverter input current _{I d} and the multiplication means 231 and inputs the inverter input power _{P InINV} the inverter input power surge determining means 232. In the inverter input power rapid increase determination means 232, when the change rate of _PinINV exceeds the "inverter input power rapid increase detection level", the "inverter input power rapid increase flag" is turned on and output.

When the "inverter input power rapid increase flag" is turned on, the switching means 233 is connected to the "T" side. Then, the previously calculated value (output of the command holding means 241) of the effective current command _IP ^* , which will be described later, is given as the upper limit value of the upper limit limiter 240 from the switching means 233 via the adding means 235 and the upper limit limiter 236. Further, the switching means 234 is connected to the "T" side for each "effective current command upper limit addition timing", and the "effective current command upper limit change amount addition value" is input to the addition means 235, resulting in the upper limit value of the upper limit limiter 240. Is gradually increased. As a result, it is possible to limit the change in the increasing direction of the active current command _IP ^* to the set change rate or less and prevent a sudden increase in the input power (output active power) of the inverter 40.

In the inverter power rapid increase suppressing means 23, the deviation between the inverter input voltage command E ^* and the inverter input voltage E is obtained by the subtracting means 238, and the effective current command is calculated by the voltage regulator 239 so that the deviation becomes zero. The upper limit value of this effective current command is limited by the above-mentioned upper limit limiter 240, and the effective current command is output as an effective current command _IP ^* .

In the current regulator 242, similarly to the current regulator 223 of FIG. 3, the active current command _IP ^* and the reactive current command _IQ ^* and the active current component and the reactive current component in the inverter output current I _o are respectively. A voltage command is generated according to the deviation and output to the adding means 407. The function of the current regulator 242 of FIG. 4 may be shared by the current regulator 223 shown in FIG.

The adding means 407 adds a compensation signal from the counter voltage compensating means 406 to the voltage command and outputs it to the switching control means 404. The switching control means 404 outputs an on / off command to the switching element of the inverter 40 based on the voltage command output from the addition means 407, and controls the operation of the inverter 40.
By the above-mentioned operation, even when the chopper unit that performs MPPT control and the chopper unit that operates in the through mode coexist, the operation of the inverter power rapid increase suppressing means 23 suppresses the rapid increase in the output power of the solar cell group when the amount of solar radiation rapidly increases. be able to.

As described above, according to this embodiment, the chopper power increasing direction change rate limiting means 21a and 21b in the chopper units 30a and 30b, the inverter power increasing direction change rate limiting means 22 in the inverter 40, and the inverter power rapid increase suppression. By providing the means 23, the rate of change in the increasing direction of the output power of the solar cell group is limited in the power converter performing MPPT control, and the chopper unit performing MPPT control and the chopper unit operating in through mode are mixed. Even in this case, it is possible to suppress a rapid increase in the output active power of the inverter 40 and prevent fluctuations in the system frequency.

The present invention is not limited to the above-described embodiment.
For example, the number of solar cell groups, chopper units, and inverters can be changed as appropriate according to the power specifications of the photovoltaic power generation system. Further, in the embodiment, it is assumed that the chopper unit is composed of one short-circuiting means and one chopper for one solar cell group, but depending on the power specifications of the photovoltaic power generation system, One solar cell group may be composed of one short-circuiting means and a plurality of choppers connected in parallel.

Further, as for the configuration of the chopper and the inverter, various conventionally provided methods can be appropriately adopted according to the power specifications of the photovoltaic power generation system. Further, as a semiconductor switching element constituting a chopper or an inverter, high-frequency switching is performed using a power semiconductor element using a wide bandgap semiconductor such as SiC (silicon carbide), gallium nitride-based material, gallium oxide-based material, or diamond. As a result, the power converter may be downsized and the loss may be reduced.

2a, 2b: Solar cell group 5: Condenser 6a, 6b: First operating point controlling means 8: Second operating point controlling means 21a, 21b: Chopper power increasing direction change rate limiting means 22: Inverter power increasing direction change rate Limiting means 23: Inverter power rapid increase suppressing means 30a, 30b: Chopper unit 40: Inverter 211,214,231: Multiplying means 212: Increasing direction change rate limiter 213,222,237,241: Command holding means 215,238: Subtracting means 216, 223, 242: Current regulator 221: Increase direction change rate limiter 232: Inverter input power rapid increase determination means 233, 234: Switching means 235: Adding means 236,240: Upper limit limiter 239: Voltage regulator 301: Multiplying means 302 : Subtraction means 303: Voltage regulator 304: Switching control means 401: Multiplication means 402: Subtraction means 403: Voltage regulator 404: Switching control means 405: PLL circuit 406: Opposite voltage compensation means 407: Addition means

Claims (5)

A plurality of chopper units that are installed corresponding to a plurality of solar cell groups and that convert the DC output voltage of the solar cell group into a DC voltage of a predetermined size by the operation of a semiconductor switching element.
An inverter that is commonly connected to the output side of the plurality of chopper units and that converts DC voltage to AC voltage by the operation of semiconductor switching elements and operates in interconnection with the power system.
A first operating point for maximizing the output power of the solar cell group by controlling the output current of the chopper unit and optimizing the operating point of the solar cell group connected to the chopper unit. Control means and
When the output voltage of the solar cell group exceeds a predetermined input voltage of the inverter, the switching operation of the chopper unit is stopped and the through mode operation of directly outputting the output voltage of the solar cell group to the inverter is executed. Function and
By controlling the input voltage of the inverter and optimizing the operating points of all the solar cell groups when all the chopper units operate in the through mode, the total output power of all the solar cell groups is maximized. A second operating point control means for converting to
In a photovoltaic power generation system equipped with
A first change rate limiting means that limits the rate of change in the increasing direction of the input power of the chopper unit in which the first operating point control means is operating so as not to exceed a predetermined value .
When the second operating point control means is operated, the second change rate limiting means for limiting the rate of change in the increasing direction of the input power of the inverter so as not to exceed a predetermined value ,
When the rate of change in the increasing direction of the input power of the inverter exceeds a predetermined value when the second rate of change limiting means does not operate, the power rapid increase suppressing means for suppressing the increase in the input power of the inverter
A photovoltaic power generation system characterized by being equipped with. In the photovoltaic power generation system according to claim 1,
The first rate of change limiting means is
A means for generating a chopper input power command based on the chopper input voltage and the chopper input voltage command obtained by the first operating point control means, and
A means for generating a chopper input current command so that the rate of change in the increasing direction of the chopper input power command does not exceed a predetermined rate of change in the increasing direction, and
A photovoltaic power generation system including a means for generating an on / off command for a switching element of the chopper unit so that a deviation between the chopper input current command and the chopper input current becomes zero. In the photovoltaic power generation system according to claim 1 or 2.
The second rate of change limiting means is
A means for generating a first effective current command so that the deviation between the inverter input voltage and the inverter input voltage command obtained by the second operating point control means becomes zero.
A means for generating the second effective current command by limiting the rate of change in the increasing direction of the first effective current command so as not to exceed a predetermined value.
A means for generating an inverter output voltage command using the second effective current command, an invalid current command, and an inverter output current, and generating an on / off command for the switching element of the inverter based on the inverter output voltage command.
A photovoltaic power generation system characterized by being equipped with. In the photovoltaic power generation system according to any one of claims 1 to 3.
The power rapid increase suppressing means is
When the rate of change in the increasing direction of the input power of the inverter exceeds a predetermined rapid increase detection level, the previously calculated value of the effective current command of the inverter is set to the upper limit value, and the upper limit of the effective current command is changed to the previously calculated value. A means for generating an effective current command with the value obtained by sequentially adding the amount addition values as a new upper limit value,
A means for generating an inverter output voltage command using the effective current command, an invalid current command, and an inverter output current, and generating an on / off command for the switching element of the inverter based on the inverter output voltage command.
A photovoltaic power generation system characterized by being equipped with. In the photovoltaic power generation system according to any one of claims 1 to 4.
The first operating point control means and the first change rate limiting means are provided in the chopper unit, and the second operating point control means, the second change rate limiting means, and the power rapid increase suppressing means are provided. A photovoltaic power generation system characterized in that it is provided in the inverter.

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