JP6308618B2 - PV power conditioner - Google Patents

Description

  The present invention relates to a PV power conditioner, and more particularly to an improvement of a PV power conditioner that converts DC power input from a solar cell into AC power and outputs the AC power to a system power supply.

  2. Description of the Related Art Conventionally, an interconnection system in which a solar cell that receives sunlight and converts it into electric power is connected to a system power supply via an inverter device called a PV (Photo Voltaic) power conditioner has been known (for example, Patent Documents). 1). Usually, in the PV power conditioner, the switching operation of the inverter circuit is controlled so that the difference between the input voltage to the inverter circuit and the target voltage, that is, the voltage deviation becomes small. Further, in order to optimize the operating point of the solar cell, the operating point control for adjusting the target voltage is performed so that the output power of the solar cell is maximized.

FIG. 4 is a diagram showing the configuration of a conventional PV power conditioner 100, in which a voltmeter 4, 7, an ammeter 5, 6, a buffer capacitor 8 and an electromagnetic contactor 9, and a reactor 17 constituting a low-pass filter. And the PV power conditioner 100 provided with the capacitor | condenser 18 for a filter, the inverter circuit 110, the MPPT control part 111, the electric current command value production | generation part 112, and the feedforward control part 113 is shown. The inverter circuit 110 is a power conversion circuit that converts DC power input from the solar battery 2 into AC power and outputs the AC power to the system power supply 3. The voltmeters 4 and 7 and the ammeters 5 and 6 measure the input voltage V ₁ , the output voltage V ₂ , the input current I _1, and the output current I ₂ of the inverter circuit 110, respectively. Here, the ammeter 5 and the voltmeter 4 take a moving average in a cycle synchronized with the commercial power source.

The MPPT (Maximum Power Point Tracking) control unit 111 adjusts the target voltage Vref based on the input voltage V ₁ and the input current I _{1 so} that the output power of the solar cell 2 is maximized. It is a point control unit. Then, the voltage deviation ΔV _{1 formed} by the difference between the input voltage V ₁ and the target voltage Vref is converted into an AC signal, and a current command value Iref is generated. The current command value Iref is a constant current control command value for obtaining a target voltage Vref that is the maximum output power determined by the MPPT control unit 111. Then, the switching operation of the inverter circuit 110 is controlled based on the current deviation ΔI _{2 formed} by the difference between the output current I ₂ and the current command value Iref. By controlling the inverter circuit 110 so that the output current _{I 2} is coincident with the current command value Iref, can be brought close to the input voltages _{V 1} to the target voltage Vref.

FIG. 5 is a diagram illustrating the operation of the PV power conditioner 100 of FIG. 4, and shows how the input voltage V ₁ and the output current I ₂ change when the input current I ₁ rapidly decreases. . The (a) of the figure, a waveform representing the time variation of the output current I ₂ is shown in the (b), shows a waveform representing the time variation of the input voltage V _1, the (c) is input waveform representing the time variation of the current I ₁ is shown. This figure shows a case where power is supplied to a 200 V system power supply 3 using a solar battery 2 having a power generation amount of about 500 kW.

If the amount of solar radiation is rapidly reduced, decreased output power of the solar cell 2, the input current I ₁ decreases sharply. Since the ammeter 5 takes a moving average, the step fluctuation of the input current I ₁ is detected as a lamp fluctuation. Meanwhile, since the detection of the input current I ₁ is delayed from the actual time, the inverter circuit 110 compensates for the shortage of the input current I ₁ from the buffer capacitor 8, but the inverter circuit 110 outputs a larger amount of power than the input power. In order to try to, the input voltage V ₁ greatly reduced.

Input current _{I 1} which is shown is generally constant until time _{t 11,} at time _{t 11,} decreased from 800A to 400A, then, are generally constant. On the other hand, the input voltage V ₁ is substantially constant until time t ₁₁ , whereas it rapidly decreases from 650 V to 575 V from time t ₁₁ to time t ₁₂ , and thereafter fluctuates for a while. Yes. Fluctuation width Vw of the input voltages _{V 1} during the period from time _{t 11} to time _{t 12} is 75V.

JP 2001-169564 A

In conventional PV power conditioner 100 described above, when decreasing the input current I ₁ rapidly by a sudden drop or the like of the solar radiation, there is a problem that the input voltages V ₁ decreases significantly. For example, by the input voltages _{V 1} significantly reduced, PV power DCUVR of conditioner 100: operating (DC Under Voltage Relay DC undervoltage) and the like, occurs inconvenience to stop the operation of the device. This defect is caused by taking a moving average with the ammeter 5 and the voltmeter 4. Further, as described above, as a buffer capacitor for compensating a shortage of the input current I _1, it is necessary to prepare an electrolytic capacitor having a large capacity, the miniaturization of cost and equipment have been inhibited.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a PV power conditioner that can suppress a decrease in input voltage when an input current rapidly decreases.

  A PV power conditioner according to a first aspect of the present invention converts a DC power input from a solar cell into an AC power based on a PWM signal and outputs the AC power to a system power supply, and an input voltage of the power conversion circuit And input power measuring means for measuring the input current, output measuring means for measuring the output current of the power conversion circuit, a buffer capacitor provided between the input power measuring means and the power conversion circuit, Based on the input voltage and the input current, the operating point control means for adjusting the target voltage so as to maximize the output power of the solar cell, and the amount of change per unit time of the input current based on the input current Current differential calculation means for obtaining current command value generation means for generating a current command value based on the difference between the input voltage and the target voltage, and the amount of change, and Based on the difference between the force current and the current command value, constituted by a PWM signal generating means for generating the PWM signal for controlling the power conversion circuit.

  According to such a configuration, since the fluctuation of the input current is taken into the current command value via the change amount of the input current per unit time, the input voltage is reduced when the input current is rapidly reduced. Can be suppressed. Therefore, the capacity of the buffer capacitor can be reduced.

  In the PV power conditioner according to the second aspect of the present invention, in addition to the above-described configuration, the current command value generation means calculates the current command value based on the sum of the difference between the input voltage and the target voltage and the amount of change. Configured to generate.

  According to such a configuration, when the amount of change per unit time of the input current is larger than the voltage deviation formed by the difference between the input voltage and the target voltage, the fluctuation of the input current can be quickly reflected in the current command value. it can. On the other hand, when the amount of change is smaller than the voltage deviation, constant voltage control according to the voltage deviation can be performed.

  The PV power conditioner according to the third aspect of the present invention outputs the change amount obtained by the current differential calculation means when the input current decreases and the input current increases in addition to the above configuration. A limiter that outputs a fixed value instead of the amount of change, and the current command value generating means calculates the current command value based on the sum of the difference between the input voltage and the target voltage and the output of the limiter. Configured to generate.

  According to such a configuration, only when the input current decreases, the fluctuation of the input current can be reflected quickly in the current command value. On the other hand, when the input current increases, for example, by outputting a fixed value 0 as the limiter output, the fluctuation of the input current is not reflected in the current command value for the increase of the input current, and the input voltage and the target It is possible to perform constant voltage control according to a voltage deviation composed of a voltage difference.

  In the PV power conditioner according to the fourth aspect of the present invention, in addition to the above-described configuration, the input power measurement means detects the input voltage and the input current over a sampling period corresponding to a sampling frequency synchronized with the frequency of the system power supply. The moving average calculating means for sampling each of the signals and outputting the average value as a measured value.

  In this PV power conditioner, there is a time lag in the sampling period before the fluctuation of the input current is reflected in the measured value of the input current. On the other hand, the amount of change per unit time of the input current is obtained using the detection time required for sampling including the calculation time as the unit time. For this reason, regardless of the responsiveness of the input power measuring means, fluctuations in the input current can be quickly reflected in the current command value.

  According to the present invention, the fluctuation of the input current is taken into the current command value via the change amount of the input current per unit time, so that the input voltage is prevented from lowering when the input current is rapidly reduced. A PV power conditioner can be provided.

It is the block diagram which showed one structural example of the PV power conditioner 1 by embodiment of this invention. Is a diagram illustrating an example of the operation of the PV power conditioner 1 of FIG. 1, the output current I _2, the input voltage V _1, the moving average of the input current I ₁ and the input current I ₁ is shown. Is a diagram illustrating an example of the operation of the PV power conditioner 1 of FIG. 1, the differential value of the moving average, the output and the correction voltage deviation [Delta] V ₁₁ of the low-pass filter is shown. It is the figure which showed the structure of the conventional PV power conditioner. It is the figure which showed operation | movement of the PV power conditioner 100 of FIG.

<PV power conditioner 1>
FIG. 1 is a block diagram showing a configuration example of a PV power conditioner 1 according to an embodiment of the present invention. The PV power conditioner 1 is an inverter device for grid connection that converts the power generated by the solar cell 2 into AC power and supplies it to the system power supply 3. The output voltage and frequency are matched with the system power supply 3, and the output waveform Is connected to the system power supply 3. Further, the PV power conditioner 1 determines a power failure and power recovery of the system power supply 3 and performs system protection control for stopping or restarting the output. Furthermore, the PV power conditioner 1 controls the operating point of the solar cell 2 and performs operating point control that maximizes the generated power.

This PV power conditioner 1 includes a voltmeter 4, 7, an ammeter 5, 6, a buffer capacitor 8 and an electromagnetic contactor 9, an inverter circuit 10, an MPPT controller 11, a current command value generator 12, and a PWM signal generator. Section 13, current differentiation calculation section 14, LPF 15 and limiter 16, reactor 17 and filter capacitor 18 constituting a low-pass filter, subtractors 21 and 23, and adders 22 and 24. The ammeter 6 that detects the output current I ₂ of the inverter circuit 10 detects the current between the reactor 17 and the filter capacitor 18.

  The solar cell 2 is a power generator that receives sunlight and converts it into electric power. In the solar cell 2, sunlight energy is directly converted into DC power using the photovoltaic effect. For example, the solar cell 2 includes a photovoltaic module in which a plurality of cells are connected in series or in parallel.

  The system power source 3 is a commercial power source that is supplied via a power network of a power company, that is, a commercial system. For example, a three-phase three-wire system power supply 3 having an AC rated voltage of 200 V and a frequency of 50 Hz is connected to the PV power conditioner 1.

The ammeter 6 and the voltmeter 7 are inverter output measuring devices that measure the output current I ₂ and the output voltage V ₂ of the inverter circuit 10, respectively. The voltmeter 4 and the ammeter 5 are input power measuring devices that respectively measure the input voltage V ₁ and the input current I ₁ of the inverter circuit 10. A digital measuring device that performs a moving average calculation is used as the voltmeter 4 and the ammeter 5.

For example, the voltmeter 4, the sampling period T1, repeatedly detects an input voltages _{V 1} at the sampling number n times, and outputs a voltage average value Vav obtained by averaging valued sum Σ a (Vdet) of the voltage detection value Vdet. The sampling period T1 corresponds to the sampling frequency f synchronized with the frequency of the system power supply 3, and T1 = 1 / f. One detection time including the calculation time is T2. For example, when the frequency of the system power supply 3 is 50 Hz, assuming that the half cycle is the sampling frequency f = 50 × 2 and the number of samplings is n = 60, T1 = 10 ms and T2 = T1 / n = 166.66667 μs.

  Here, an example in which the voltage average value Vav is calculated using a ring buffer having (n + 1) buffer values will be described. A ring buffer having (n + 1) buffer values has buffers at addresses 0 to n. Write the first voltage detection value Vdet1 to the address 0 of the ring buffer, then write the second voltage detection value Vdet2 to the address 1 of the ring buffer, and write the voltage detection value Vdet while sequentially incrementing the address in this way. I do. When the sampling period T1 elapses, the nth detected voltage value Vdetn is written at address (n−1). The voltmeter 4 calculates the sum Σ (Vdet) = Σ (Vdet1 to Vdetn), divides the sum Σ (Vdet) by the number of samplings n, and calculates the voltage average value Vav = [Σ (Vdet)] / n Get.

  Next, when the detection time T2 elapses after the lapse of the sampling period T1, the oldest voltage detection value Vdet1 is written in the 0th address of the ring buffer, and (n + 1) pieces are written in the nth address of the adjacent ring buffer. The voltage detection value Vdet (n + 1) of the eye is written, the latest voltage detection value Vdet (n + 1) is added to the previous sum Σ (Vdet) = Σ (Vdet1 to Vdetn), and the oldest voltage detection value Vdet1 is subtracted. This result is divided by the number of samplings n to obtain the latest voltage average value Vav.

  The average voltage value Vav when the mth detected voltage value Vdetm is detected is Vav = {[Σ (Vdet) + Vdetm] −Vdet (m−n)} / n. However, here, Σ (Vdet) = Σ (Vdet (mn) to Vdet (m-1)). The ammeter 5 has the same configuration as that of the voltmeter 4 described above.

  The buffer capacitor 8 is a capacitive element for backing up the input power when the output power of the solar cell 2 is lowered, and is provided between the ammeter 5 and the inverter circuit 10. For example, an electrolytic capacitor is usually used as the buffer capacitor 8. However, if the present invention is applied as described later, a film capacitor having a small capacity can be used. The magnetic contactor 9 is a relay for disconnecting the inverter circuit 10 from the system power supply 3.

The inverter circuit 10 is a power conversion circuit that converts DC power input from the solar cell 2 into AC power and outputs the AC power to the system power supply 3 by a switching operation of the semiconductor element. The MPPT controller 11 is an operating point controller that adjusts the target voltage Vref based on the measured values of the input voltage V ₁ and the input current I ₁ so that the output power P ₁ of the solar cell 2 is maximized. The output power P ₁ is obtained from P ₁ = V ₁ × I ₁ .

The output characteristics (VI characteristics) of the solar cell 2 vary depending on the amount of solar radiation and temperature. For this reason, if the output voltage of the solar cell 2, that is, the input voltage V ₁ is controlled by MPPT (maximum power point tracking) control and the operating point on the output characteristics is optimized, the output power P ₁ is maximized. be able to. In the MPPT control unit 11, the optimum value of the target voltage Vref is obtained using the hill-climbing method. In the hill-climbing method, the current input voltage V ₁ and the output power P ₁ are set to Vo and Po, the target voltage Vref is changed by a certain amount ΔVref, for example, the target voltage Vref is changed in a lowering direction, and the output power before and after the change is changed. comparing P _1, if is larger after the change of the output power _{P 1,} further lowers the target voltage Vref. Repeat this, when the output power P ₁ after the change is smaller than before the change, the target voltage Vref immediately before it is determined that the maximum output power point, the target voltage Vref immediately before the target value. In this way, the optimum value of the target voltage Vref is obtained.

The subtractor 21 obtains a difference between the voltage average value Vav and the target voltage Vref, and outputs the difference as a voltage deviation ΔV ₁ to the adder 22. The voltage deviation ΔV ₁ is ΔV ₁ = (Vav−Vref). The adder 22 calculates the sum of the voltage deviation [Delta] V ₁ and the limiter output _{D 1,} and outputs the current command value generating section 12 as the correction voltage deviation [Delta] V _11. The correction voltage deviation ΔV ₁₁ is ΔV ₁₁ = (ΔV ₁ + k × D ₁ ). k is a fixed value and consists of a predetermined real number.

The current differential calculation unit 14 obtains a differential value composed of the change amount ΔI ₁ per unit time of the current average value Iav. As shown in FIG. 2, when the input current I ₁ continues for a predetermined value is rapidly lowered, current average Iav is gradually decreased stepwise over the sampling period T1. The change amount ΔI ₁ of the current average value Iav, which is a differential value, appears as a discrete line on the minus side as shown in FIG. When this change amount ΔI ₁ is passed through an LPF (low-pass filter) 15, a negative pulse signal having a width of the sampling period T 1 and having an amplitude corresponding to the current drop is generated. In the case where the input current I ₁ is increased rapidly, although the these upper and lower inverted waveform, the pulse signal of the positive side by the limiter 16 to be described later is cut.

Limiter 16, of the pulse signal output from the LPF 15, as a definition of the lower limit of the negative side of the pulse signals as well as cutting the plus side, and outputs the limiter output D _1. When the magnitude of the pulse signal is a fixed value [Delta] I ₀ is greater than a lower limit value, as a limiter output D _1, and outputs the fixed value [Delta] I _0. Incidentally, if the input current I ₁ rises, the pulse signal of the positive side is outputted from the LPF 15, to cut the pulse signal plus direction by the limiter 16, and outputs the fixed value 0 as a limiter output D _1. The limiter output D ₁ is added to the voltage deviation ΔV ₁ by the adder 22 to generate a corrected voltage deviation ΔV _11, which is sent to the current command value generation unit 12. By providing such a limiter 16, only when the input current I ₁ is reduced, it is possible to quickly reflect the change in the input current I ₁ to the current command value Iref. On the other hand, when the input current I ₁ increases, constant voltage control according to the voltage deviation ΔV ₁ can be performed.

The current command value generation unit 12 includes a voltage deviation limiter 31, an oscillator 32, and a multiplier 33. Voltage deviation limiter 31 is a protecting circuit of the inverter circuit 10, the correction voltage deviation [Delta] V ₁₁ compared with the upper limit value ΔVupper and the lower limit value DerutaVunder, the correction voltage deviation [Delta] V ₁₁ is the upper limit ΔVupper less and, at least as large as the lower limit DerutaVunder If there is, the correction voltage deviation ΔV ₁₁ is output to the multiplier 33. On the other hand, voltage deviation limiter 31 is either corrected voltage deviation [Delta] V ₁₁ exceeds the upper limit value DerutaVupper, or, if less than the lower limit DerutaVunder, fixed upper limit DerutaVupper, or outputs a fixed lower limit DerutaVunder.

The oscillator 32 generates a reference sine wave having the same frequency as that of the system power supply 3 and outputs the reference sine wave to the multiplier 33. The multiplier 33 generates a current command value Iref by multiplying the output of the voltage deviation limiter 31 by the reference sine wave. The subtracter 23 outputs a current deviation ΔI ₂ based on the difference between the current command value Iref and the output current I ₂ . Based on the correction voltage deviation [Delta] V ₁₁ is the sum of the limiter output _{D 1} generated from the variation [Delta] I ₁ of the voltage deviation [Delta] V ₁ and the input current _{I 1,} by determining the current command value Iref, the change of the input current _{I 1} When the amount ΔI ₁ is larger than the voltage deviation ΔV ₁ , the constant current control can be performed by quickly reflecting the fluctuation of the input current I _{1 in} the current command value Iref. On the other hand, when the amount of change [Delta] I ₁ of the input current I ₁ is smaller than the voltage deviation [Delta] V ₁ is able to perform the constant voltage control in accordance with the voltage deviation [Delta] V _1.

The adder 24 calculates the sum of the current deviation ΔI ₂ and the output voltage V ₂ and outputs the sum to the PWM signal generation unit 13. The PWM signal generator 13 includes a carrier wave generator 34 and a comparator 35. The carrier wave generation unit 34 generates a carrier wave for generating a PWM signal and outputs the carrier wave to the comparator 35.

The comparator 35 is a comparator that compares the sum of the current deviation ΔI ₂ and the output voltage V ₂ with the waveform of the carrier wave and outputs a binary signal indicating the comparison result as a PWM signal, and is composed of an operational amplifier. The comparator 35 receives the sum of the current deviation ΔI ₂ and the output voltage V ₂ as an inverting input, receives a carrier wave as a non-inverting input, and outputs a PWM (Pulse Width Modulation) signal to the inverter 10. To do. The PWM signal here controls the inverter circuit 10 so that the output current I ₂ matches the current command value Iref, thereby bringing the input voltage V ₁ closer to the target voltage Vref.

Conventionally, when a moving average calculation is used as a detected value of input power, there is a time lag of the sampling period T1 until a change in input power is detected. Therefore, output is performed using the buffer capacitor 8 during the sampling period T1. Since power was controlled, it was necessary to provide a buffer capacitor 8 having a large capacity. However, according to the present invention, the change in the input power is differentiated and the current command value Iref is generated based on the change amount ΔI ₁ per unit time, so that the change in the input power can be immediately responded. Responsiveness can be accelerated. Therefore, conventionally, an electrolytic capacitor having a large capacity has been used as the buffer capacitor 8. However, by applying the present invention, a film capacitor having a small capacity and having a self-recovering function can be used. Therefore, the PV power conditioner 1 can contribute to downsizing and improved reliability.

2 and 3 are views showing an example of the operation of the PV power conditioner 1 of FIG. 1, the input current I ₁ shows a case where rapidly decreased. 2A to 2D show moving averages of the output current I ₂ , the input voltage V ₁ , the input current I _1, and the input current I ₁ , respectively. 3A to 3C show the moving average differential value, the output of the low-pass filter, and the correction voltage deviation ΔV ₁₁ . This figure shows a case where power is supplied to the system power supply 3 using the solar battery 2 having a power generation amount of about 500 kW.

Input current _{I 1} is substantially constant until time _{t 1,} at time _{t 1,} decreased from 800A to 400A, then, it is generally constant. On the other hand, the input voltages _{V 1,} compared generally is constant until time _{t 1,} during the period from time _{t 1} to time _{t 2, the} rapidly decreases from 650V to 600V, then, for a while, vary Yes. Fluctuation width Vw of the input voltages _{V 1} during the period from time _{t 1} to time _{t 2} is about 50 V.

The correction voltage deviation ΔV ₁₁ is the sum of the voltage deviation ΔV _{1 formed by} the difference between the input voltage V ₁ and the target voltage Vref, and the change amount ΔI ₁ per unit time of the input current I ₁ . Measured value of the input current I _1, since obtained by moving average operation, before change of the input current I ₁ is reflected on the measurement value, a time lag of the sampling period T1. However, in the present invention, the voltage deviation ΔV ₁ is corrected on the basis of the change amount ΔI ₁ made up of the differential value of the input current I ₁ to generate the corrected voltage deviation ΔV ₁₁ . That is, immediately detect that the input current I ₁ is changed, are reflected in the control. Therefore, regardless of the response of the input power measurement device, fluctuation of the input current I ₁ is quickly reflected.

In PV power conditioner 1 according to this embodiment, since the fluctuation of the input current I ₁ is taken into the current command value Iref through the change amount [Delta] I _1, the output at the timing when the input current I ₁ begins to decrease current I ₂ Can be narrowed down quickly. By narrow the output current I ₂ in this manner, it is possible to suppress the variation width Vw of the input voltages V ₁ when the input current decreases sharply. Thus, it is possible to immediately reflected in controlling sudden drop of the input current I _1, it is possible to reduce the capacity of the buffer capacitor 8.

  In the present embodiment, an example of a chopperless type power conditioner in which the power conversion circuit that converts the DC power input from the solar cell 2 into AC power and outputs the AC power to the system power supply 3 is composed only of the inverter circuit 10 is described. Although demonstrated, this invention does not limit the structure of a power converter circuit to this. For example, the present invention can also be applied to a case where the power conversion circuit includes a chopper circuit that boosts a DC voltage and an inverter circuit that converts a DC voltage input from the chopper circuit into an AC voltage.

DESCRIPTION OF SYMBOLS 1 PV power conditioner 2 Solar cell 3 System power supply 4,7 Voltmeter 5,6 Ammeter 8 Buffer capacitor 9 Electromagnetic contactor 10 Inverter circuit 11 MPPT control part 12 Current command value generation part 13 PWM signal generation part 14 Current differentiation Calculation unit 15 LPF
16 Limiter 17 Reactor 18 Filter capacitors 21 and 23 Subtractors 22 and 24 Adder 31 Voltage deviation limiter 32 Oscillator 33 Multiplier 34 Carrier wave generation unit 35 Comparator

Claims (3)

Based on the PWM signal, the power conversion circuit that converts the DC power input from the solar cell into AC power and outputs it to the system power supply,
Input power measuring means for measuring the input voltage and input current of the power conversion circuit;
Output measuring means for measuring the output current of the power conversion circuit;
A buffer capacitor provided between the input power measuring means and the power conversion circuit;
Based on the input voltage and the input current, operating point control means for adjusting the target voltage so that the output power of the solar cell is maximized;
Based on the input current, current differential calculation means for obtaining a change amount per unit time of the input current,
Current command value generating means for generating a current command value based on the difference between the input voltage and the target voltage, and the amount of change;
PWM signal generation means for generating the PWM signal for controlling the power conversion circuit based on the difference between the output current and the current command value ,
The PV power conditioner, wherein the current command value generating means generates the current command value based on a sum of a difference between the input voltage and the target voltage and the amount of change . When the input current decreases, the change amount obtained by the current differential calculation means is output, and when the input current increases, a limiter is provided that outputs a fixed value instead of the change amount,
2. The PV power condition according to claim 1 , wherein the current command value generating unit generates the current command value based on a sum of a difference between the input voltage and the target voltage and an output of the limiter. Na. The input power measuring means samples the detected values of the input voltage and the input current over a sampling period corresponding to a sampling frequency synchronized with the frequency of the system power supply, and outputs the average value as a measured value. It has a means, The PV power conditioner of Claim 1 or 2 characterized by the above-mentioned.

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