JP2012070598A - Method for avoiding output suppression of multiple interconnected photovoltaic power generation systems and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for correcting inequality in an output suppression amount between users (houses) only by adding a function to an existing apparatus in a power distribution system with multiple interconnected photovoltaic power generation systems.SOLUTION: A method for avoiding output suppression according to the present invention comprises: measuring end voltages of PCSs 7 of all houses 5 in a district where multiple photovoltaic power generation systems 6 are interconnected to the power distribution system at a certain time; calculating a difference between the end voltage at the PCS 7 of the house 5 which shows the highest voltage and 107.5 V which is a preset power management value; and setting an operation voltage for voltage rise suppression function to the PCS 7 of each house 5 by setting the set value of the PCS 7 of the house 5 which shows the highest voltage at 107.5 V and setting the set value of the PCS 7 of each of the other houses at a voltage obtained by adding the difference to each measured voltage.

Description

The present invention relates to a method and an apparatus for avoiding suppression of solar light output in a distribution system in which a large number of solar systems are connected.

In general, a photovoltaic power generation (PV) system has been installed in a plurality of consumers (housing) that are fed from the same distribution system. In the photovoltaic power generation system, DC power generated in the solar cell panel is converted into AC power by a power conditioner (PCS) and supplied to the load of the consumer, and surplus power is flowing backward to the AC system side.

When many photovoltaic power generation systems are connected to the same distribution system, the system voltage rises due to the reverse power flow flowing out from each house. In particular, when the generated power is large and the load power is low, such as Golden Week, a case is assumed in which the voltage deviates from the voltage management value obtained by adding the upper limit value defined by the Electricity Business Act and the extension of the extension voltage.

In this case, the PV system is required to operate to maintain an appropriate voltage, and deviated from the voltage management value by the voltage rise suppression function (phase advance reactive power control function, output suppression function) provided in the PCS of each house. In this case, as shown in FIG. 12, particularly in some houses connected to the terminal, the output suppression function operates when the voltage rises, and operation in which generated power is suppressed (hereinafter, output suppression) is performed. Such a voltage rise suppression function of the PV system is described in paragraph 0003 of Patent Document 1 below, for example.

In this case, in spite of sufficient solar radiation, the power generation output is suppressed and the power generation efficiency is reduced. Moreover, since the capacity | capacitance and system | strain structure of photovoltaic power generation change with houses, it is also considered that the fall of power generation efficiency is biased to a specific house.

On the other hand, as a countermeasure against voltage rise, the PCS is allowed to advance phase reactive power control in the range where the power factor of the power receiving point is 85% or more, and if this allows the appropriate voltage to be maintained, the power generation output is suppressed. Although it is not necessary, since voltage variation occurs between houses, the amount of output suppression varies from house to house.

JP 2008-154334 A

In this way, when multiple photovoltaic power generation systems are connected, voltage fluctuations occur between houses, but the voltage rise suppression function minimizes the amount of output suppression between all houses and compensates for fluctuations between houses. The control method has not been established. If the voltage rise suppression function is set to the same set value for all the buildings (the voltage at which the voltage rise suppression function set in advance in each PCS operates), there will be unfairness in the output suppression amount and reactive power output between houses. Can be considered. As a result, the amount of electricity sold is small in houses where output suppression is large, and the amount of power sold is large in houses where output suppression does not occur so much, resulting in low-income houses and many houses, resulting in income inequality. It will be.

That is, since the PCS installed in each house has a voltage rise suppression function, even if there is sufficient solar radiation, if the local voltage is rising, the PCS output suppression function As a result, the amount of power (power generation efficiency) flowing backwards decreases.

However, since the power generation amount of photovoltaic power generation becomes very large during the daytime, even if the power consumption of each house differs, the power consumption is smaller than the power generation amount. For this reason, there is no great difference in daytime power consumption between houses.

Therefore, in view of these prior arts, the present invention is a distribution system in which a large number of photovoltaic power generation systems are connected to each other, and by simply adding a function to an existing device, the output suppression amount of all consumers of the distribution system can be reduced. An object of the present invention is to provide an output suppression avoidance method for a photovoltaic power generation system and a system thereof that can minimize and correct inequalities in the amount of output suppression between consumers.

According to the first aspect of the present invention, in a region where a photovoltaic power generation apparatus is connected to a plurality of consumers in one distribution system, the PCS of the consumer having the photovoltaic power generation apparatus performs voltage management when the voltage rises. In order not to deviate from the value, the PCS end voltage of all the consumers in a certain region at a certain time is measured, and the difference between the PCS end voltage of the consumer showing the highest voltage and the voltage management value is calculated. The set value of the PCS of the consumer showing the highest voltage is set to the same value as the voltage control value, and the set value of the PCS of the other consumers is set to the value obtained by adding the difference to the measured voltages. A method of avoiding output suppression at the time of voltage increase in reverse power flow of a photovoltaic power generation system connected to a large number of units, wherein a set value of PCS is set for a consumer.

According to the second aspect of the present invention, in a region where a photovoltaic power generation apparatus is connected to a plurality of consumers in a single distribution system, the consumer PCS provided in the photovoltaic power generation apparatus performs voltage management when the voltage rises. In order not to deviate from the value, the PCS of each photovoltaic power generation system is connected to a server, and each PCS measures the PCS terminal voltage according to a command from the server, and transmits the measured voltage to the server. The server calculates the difference between the terminal voltage of the consumer PCS that shows the highest voltage of each of the PCS and the voltage management value, and sets the set value of the consumer PCS that shows the highest voltage. Set the same value as the voltage management value, set the PCS settling value of other consumers as the value obtained by adding the above difference to each measured voltage, set the settling value of the PCS to each consumer, and set these set voltages. Send to each PCS Each PCS has a configuration in which each PCS is configured to set a set value transmitted from the server, and is an output suppression avoidance system at the time of voltage increase in reverse power flow of a photovoltaic power generation system linked to multiple units .

According to a third aspect of the present invention, when the set time or condition is satisfied, the server automatically instructs each PCS to measure the set value of each PCS, and the measured voltage of each PCS. The multi-unit-connected photovoltaic power generation system according to claim 2, wherein data is collected and calculated, a set value of each PCS is set, and transmitted to a control unit of each resettable PCS. An output suppression avoidance system at the time of voltage rise in reverse power flow was adopted.

As in the first aspect of the invention, by setting the PCS set value for each consumer, the power output suppression amount of all the consumers is minimized, and the variation in the power output suppression amount and the reactive power output among the consumers. Can be minimized, and inequality in the amount of electricity sold by customers in the same distribution system can be corrected, and an increase in the overall voltage of the distribution system can be suppressed.

In addition to the effect of the invention of claim 1, the invention of claim 2 is provided with a server connected to the PCS of the solar power generation system of each consumer, and this server provides an end voltage of the PCS of each consumer. Measurement, calculation, and setting of setting values can be converted to IT and processed automatically.

Further, according to the invention of claim 3, when the PV system of the distribution system is added, the system configuration changes due to the change of the section switch, or the case where the power generation amount and the load amount change due to the season When the setting conditions and the set time are satisfied, the server automatically operates to set the set value of each PCS, so that inequality among consumers can be finely resolved.

The present invention measures the PCS end voltage of all the customers in a region where a large number of photovoltaic power generation devices are connected to the distribution system at a certain time, and the end of the PCS of the consumer that showed the highest voltage among them. The voltage management value is calculated by adding the voltage, the upper limit value of the Electricity Business Law and the extension of the extension voltage. For example, the set value of the PCS of the consumer showing the highest voltage is set to 107.5 V which is the voltage management value. The setting value of the PCS of other consumers is set as the voltage obtained by adding the difference to the measured voltage, and the setting value of the PCS is set for each consumer. This is a method for avoiding output suppression in the power generation system.

Thereby, the electric power output suppression amount of all the said consumers can be minimized, and the dispersion | variation in the electric power output suppression amount and reactive power output between consumers can be minimized.

Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing interconnection of customers (housing) in which a large number of photovoltaic power generations are linked to a power distribution system used in the method of the present invention.

In FIG. 1, a high-voltage distribution line 2 is led out from a substation 1, and a plurality of pole transformers 3 are provided at intervals in the high-voltage distribution line 2. Electric power is supplied from each of these pole transformers 3 to a plurality of houses 5 via low-voltage distribution lines 4, and each house 5 is provided with a solar power generation system 6. 6 is provided with a power conditioner (PCS) 7. The DC power generated in the solar panel of the solar power generation system 6 of each house 5 is converted into AC power by the PCS 7 and supplied to the load 8 of the house 5. The surplus power is flowing backward to the distribution system side.

In addition, the PCS 7 of each house 5 is connected to the server 9 via the Internet, LAN, or wireless. Of course, the PCS 7 and the server 9 can be connected via a power line (PLC). In FIG. 1, the server 9 is described as being installed at a location distant from each PCS 7, but this server 9 may be provided in a specific PCS 7, It may be installed in other places.

Further, each PCS 7 has a voltage measurement function, a function for changing the set value by an external control signal, a voltage control function for maintaining a voltage management value, and the like. In addition, the server 9 has a function of instructing each PCS 7 to measure voltage at a certain time, and also receives and records the measured voltage from each PCS 7, and the PCS of the PCS 7 of the house 5 showing the highest voltage. The difference between the terminal voltage and the voltage management value in the distribution system is calculated, the PCS terminal voltage of the PCS 7 of the house 5 showing the highest voltage is set to the same value as the voltage management value, and the PCS 7 of the other house 5 is set. A function for setting the value by adding the difference to the measured voltage, and a function for determining the set value of the PCS 7 of each house 5 and transmitting the value to the PCS 7 of each house 5 in this way. ing. Accordingly, when the PCS 7 of each house 5 receives the set value from the server 9, it changes to the set value.

In such a power distribution system, we established a method for setting the PCS settling value to minimize the output suppression amount of all the houses and to minimize the variation in output suppression amount and reactive power output between houses.

A specific method is as shown in FIG.
Step S1: The end voltage of the PCS 7 of each house 5 is measured at the power generation output around 10 am. However, when the voltage rise suppression function is operating, the delivery voltage of the substation 1 is lowered until the voltage increase suppression function is not activated.
Step S2: The difference ΔV between the end voltage (Vmax) of the PCS 7 having the highest voltage measured in Step S1 and 107.5 V which is the upper limit of the voltage management value is calculated.
Step S3: The setting value of the PCS 7 of the house 5 where Vmax is measured is set to 107.5V.
Step S4: The PCS 7 of the other house 5 The voltage obtained by adding ΔV to the end voltage measured in step is taken as the settling value.

In the following, a simulation will be conducted to verify the effect of phase-advanced reactive power control on avoiding output suppression in a general distribution system configuration and the method of setting the operating voltage for each house.

FIG. 3 shows the configuration of the high-voltage distribution system among the distribution system configurations, in which the pole transformers 3 are distributed at the same intervals on the high-voltage wiring 2 from the substation 1 and the electric wires are AL120 mm ² . . FIG. 4 shows a configuration in which 15 low-voltage distribution lines 4 supply 15 houses 5 from one pole transformer 3, and low-voltage distribution lines 4 have ALOC 120 mm ² and low-voltage service lines SV 14 mm ^2. It is used CV5.5Mm ² to wire up for PCS PV from board.

The power generation / load power pattern was measured at 553 houses in Ota City, Gunma Prefecture in the New Energy and Industrial Technology Development Organization (NEDO) project “Centralized Photovoltaic Power Generation System Demonstration Study”. Were used after averaging. As a representative day, we extracted the day of Golden Week (Apr 29, 2007), the most concerned about the occurrence of output suppression in the year. FIG. 5 shows the power generation / load pattern used in the simulation. The generated power amount of the day was 21.7 kWh, the load power amount was 21.9 kWh, and the reverse flow power amount was 15.5 kWh.

The distribution line feed voltage was fixed at 6660 V (low voltage conversion value 106.0 V) in order to confirm the influence on the output suppression by the PV system multi-unit interconnection under the condition that the voltage control is not performed on the system side.

Regarding the voltage control of the PCS, the specifications of the output suppression control and the phase advance reactive power control are the operation voltage of 107.5V for both the output suppression function and the phase advance reactive power control, and the return voltage is 0.2V from the operation voltage. 107.3 V is low, and the fast reactive power control sets the power factor to 1 to 0.85.

As a method of injecting reactive power, the control method of injecting reactive power using a system power supply while maintaining PV generated power was used. The operation of the PCS voltage control function when the system voltage rises is as follows. If the system voltage is out of the proper value as a result of the power flow calculation, the power factor is reduced (the phase reactive power is output) until it falls within the proper range. If the voltage exceeds the appropriate value even when the power factor reaches the set value, the voltage control is performed in two steps in which the output control function operates so as to be within the appropriate voltage.

Next, as described with reference to FIG. 12, when a large number of PV systems are connected to the same distribution system, the voltage tends to increase toward the end of the system. Therefore, it is assumed that the output suppression amount also varies among houses depending on the grid connection position. Therefore, an algorithm for minimizing the overall output suppression amount, the output suppression amount between houses, and the variation in reactive power output is examined by a three-stage approach.

The goal of the first stage was to confirm the effect of reducing the output suppression amount by the phase advance reactive power control. In this study, when the phase advance reactive power control function is masked, the output suppression amount when the phase advance reactive power control function is enabled with the power factor setting of 0.85 is compared. However, the distribution line distance is set to 0 to 10 km in steps of 2 km, and the setting values for PCS voltage control are standardized for all houses, and the output suppression amount of the house with the largest output suppression amount per pole transformer is evaluated. .

The goal of the second stage was to establish a PCS voltage control settling value for minimizing the amount of output suppression without outputting reactive power as much as possible. In this study, the power factor setting of the fast reactive power control is used as a parameter to understand the effect of the output suppression amount on the reduction of the total sum of all the houses. However, the distribution line distance was set to 0 to 10 km in increments of 2 km, the setting values of PCS voltage control were unified for all the houses, and evaluation was performed based on the output suppression avoidance rate (see Equation 2) for all the houses.

FIG. 6 shows the output of reactive power and apparent power with respect to the set power factor when the PCS active power is 3 kW. It can be seen from FIG. 6 that the PCS capacity (apparent power) is the largest when the power factor is 0.85, in which case the reactive power is about 1.8 kvar and the PCS capacity is about 3.5 kVA. Karu.

The target of the third stage is to establish a voltage control settling value for minimizing the variation in the output suppression amount and the reactive power injection amount between houses while maintaining the second stage target. In this study, the sum of the output suppression amount and the output suppression of each house when the power factor setting of phase reactive power control for each house and the operating voltage (Vo: Operating voltage) of PCS voltage control are used as parameters. Understand the impact on quantity and reactive power output variability. Originally, in order to optimize the entire PCS voltage control function, in addition to the operating voltage, the return voltage and change rate should be used as parameters, but this time, the essential control logic is not touched. The return voltage is fixed at a value 0.2 V lower than the operating voltage as shown in Equation 1. In this control logic, the set values of the operation / return voltage of the output suppression function and the phase advance reactive power control function are common.

_{V r} = V o -0.2 ......... Formula 1
V _r : PCS voltage control return voltage V _o : PCS voltage control operating voltage

Next, we examined the simulation conditions for establishing a settling value that minimizes the amount of output suppression and the variation in the amount of output suppression and reactive power injection between houses. Table 1 shows the simulation conditions for the six patterns implemented this time.

Of the six patterns shown in Table 1, Tr-1 and Tr-2 are setting parameters for correcting variations in output suppression amount and reactive power between houses in units of low-voltage distribution lines. Although it is impossible to correct the voltage variation due to the power flow of the high-voltage distribution line, there is an advantage that the operating voltage can be determined by a small-scale system. On the other hand, All-1, All-2, and All-3 are methods for changing the operating voltages of all PV systems on the same distribution line. A specific method for determining the operating voltage will be described with reference to FIG.

The operating voltage of each house of All-1, All-2, and All-3 is determined by the following procedure.
1. Calculation of the potential difference between the substation and each house The power flow is calculated using the power generation / load pattern shown in FIG. 5 with the sending voltage lowered so that the voltage control of the PCS does not operate. The time when the reverse power flow is greatest (AM11: 34) and the time when the reverse power flow starts (AM6: 55) are divided into three equal parts, and the times when the reverse power flow is different (AM8: 28, AM10: 01, AM11: 34) Calculate the potential difference between the substation and each house.
2. Determination of the operating voltage of the voltage rise suppressing function of each house The operating voltage of Tr5TM1, which is most likely to increase the voltage, is 107.5V. Based on the potential distribution calculated in step 1, the operating voltage of the voltage rise suppression function for other houses is determined. The operation voltage of the voltage rise suppression function calculated using the reverse flow voltage of AM8: 28 is All-1, the operation voltage of the voltage rise suppression function calculated using AM10: 01 is All-2, and the reverse flow of AM11: 34 The operating voltage of the voltage rise suppression function calculated using electric power is defined as All-3.

The output suppression amount was calculated by simulation analysis using the parameters shown above. FIG. 8 shows the daily output suppression amount of a house having the largest output suppression amount among the pole transformers when the PCS control uses only the output suppression function and the phase advance reactive power control in combination.

As shown in FIG. 8 (a), when phase reactive power control is not used together (output suppression function and output suppression function only), even if the total length of the high-voltage distribution line is 0 km, ideal output suppression does not occur in the worst case. When the maximum output of about 4 kWh corresponding to about 18% of the generated power (21.7 kWh) occurs and the total length of the high-voltage distribution line is 10 km, it corresponds to about 47% of the ideal generated power in the worst case. It was confirmed that there is a house where output suppression of 10.1 kWh occurs. On the other hand, as shown in FIG. 5B, when the phase-advanced reactive power control is used together, the output suppression amount is greatly reduced, and the output suppression amount becomes almost zero regardless of the line length of the high-voltage distribution line. I was able to confirm.

In addition, from the above results, it was decided to confirm the effect of changing the power factor setting value of the phase reactive power control on the change in the output suppression amount. This was implemented using the output suppression avoidance rate, the output suppression amount of each house, and the distribution of reactive power output defined by Equation 2.

FIG. 9 shows the correlation between the set power factor and the output suppression avoidance amount, and FIG. 10 shows the distribution of the output suppression amount and the phase reactive power output for each house when the total length of the high-voltage distribution line is 10 km. In addition, the reactive power of FIG.10 (b) extracted the data of the time when the apparent power is the largest in the said house.

From FIG. 9, in any case, the output suppression avoidance rate increases as the set power factor is lowered. When the distribution line distance is 10 km and the set power factor is 0.85, the output suppression avoidance rate is about 25% at the maximum. It was confirmed that

Moreover, it was confirmed that the reactive power / output suppression amount of each house is the largest in the house 1 and the smallest in the house 7, regardless of the set power factor as shown in FIG. This tendency becomes more prominent as the power factor setting of the advanced reactive power control is made smaller, so it is an unfavorable operation from the viewpoint of the amount of output suppression between houses and compensation for variations in reactive power output. .

Based on these results, the next step was to verify the output suppression amount between houses and the effect of reducing the variation in reactive power by changing the PCS voltage control set value for each house. The setting value for each house is the operating voltage of all PV systems in the same distribution line as the method of making a difference in pole transformer units to correct the output suppression amount and reactive power variation between houses in the low voltage distribution line unit. It verified in two ways of changing. The former has the advantage that the set value can be determined by the voltage distribution in the pole transformer.
On the other hand, the latter has an advantage that the voltage distribution of the entire distribution line can be taken into account, but has a disadvantage that a detailed simulation for simulating all houses is required.

In fact, in the simulation that was conducted this time, the former used a method in which a difference of 0.1V or 0.2V settling value was given to a house that is likely to increase in voltage according to the voltage distribution in the pole transformer, an intermediate house, or a house that is difficult to increase the voltage. However, the latter voltage distribution is obtained by reducing the sending voltage so that the voltage control function of the PCS does not operate, and the time when the reverse power flow is the largest (AM11: 34) and the time when the reverse power flow starts (AM6: 55) are 3 Calculate the potential difference between the substation and each house at different times (AM8: 28, AM10: 01, AM11: 34) when the reverse power flow is equally divided, and the operation of the Tr5TM1 voltage rise suppression function where the voltage rises the most The simulation was carried out by the process of determining the settling value based on the potential distribution calculated with a voltage of 107.5V.

As a result of simulation, when operating with the settling value (All-3) calculated with the reverse power flow of AM11: 34, the output suppression avoidance rate is the highest, compared to the case where the same settling value is used in all the houses. It was confirmed that the output suppression avoidance rate was increased by about 10%. However, in this operation, it was confirmed that there is a drawback that the amount of output suppression between houses and the variation of reactive power output are large. On the other hand, when operating with a settling value (All-2) calculated with the reverse power flow of AM10: 01, the output suppression avoidance rate is equivalent to All-3, and the output suppression loss amount between houses and the standard of reactive power output It was confirmed that the deviation was the smallest among all operations. In order to evaluate this quantitatively, a weighting function was given to the output suppression avoidance rate, the variation in the amount of output suppression between houses, and the variation in reactive power, and an overall evaluation was performed.

In other words, the overall evaluation was evaluated using three items: (1) output suppression avoidance rate, (2) variation in output suppression amount between houses, and (3) variation in reactive power output.

In order to optimize the voltage control function for avoiding output suppression, the above three items are all important, but an evaluation that can make a difference in importance from the viewpoint of reducing loss and did. The evaluation was performed using the standardized output suppression avoidance rate defined by Equation 3, the variation in the amount of output suppression between houses, and the determination coefficient Jc shown in Equation 4 using the variation in reactive power output.

The determination coefficient Jc is the largest when the output suppression avoidance rate is the highest and there is no variation in the output suppression amount between the houses and the reactive power output. In addition, the weighting factor takes into account the importance of each parameter, and two cases (α = 1, β = 0.5, γ = 0.5), (α = 1) where the values are assigned to α, β, γ. , Β = 0.5, γ = 0.25) and the case (α, β, γ = 1) in which α, β, γ are set to the same value, and the evaluation was started. FIG. 11 shows determination coefficient calculation results for each condition.

From FIG. 11, in the weighting factor and power factor condition set this time, in all cases, All-2 has the largest determination coefficient, and power factor setting 0.875 to 0.9 has the largest determination coefficient. Therefore, it was found that this operation is the most efficient under the conditions set this time.

From the above simulation, the setting value is set to AM10: 01, but the present invention is not limited to this time.
When the setting conditions such as the load of each customer and the fluctuation of the generated power and the set time are satisfied, the server automatically operates, the voltage of each PCS 7 is measured by each PCS 7, and the operating voltage is applied to each PCS 7. Can also be set.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows the connection of the consumer (house | housing) by which many photovoltaic power generations were connected to the power distribution system used for the method of Example 1 of this invention. It is a flowchart which shows the settling method of the set value of each PCS in Example 1 of this invention. It is a block diagram of the high voltage | pressure distribution system in the simulation of Example 1 of this invention. It is a block diagram of the low voltage | pressure distribution system in the simulation of Example 1 of this invention. It is an electric power generation and load pattern graph figure in the simulation of Example 1 of this invention. It is a graph which shows the relationship of the reactive power and the apparent power with respect to the setting power factor at the time of PCS active power 3kW in the simulation of Example 1 of this invention. It is a block diagram of the operation | movement determination method of each house of a power distribution system in the simulation of Example 1 of this invention. It is a graph which shows the amount of output suppression loss of the day in the simulation of Example 1 of this invention, (a) A figure is a case where only output suppression control is performed, (b) A figure is phase advance reactive power control and output suppression control. It is the same graph in the case of using together. It is a graph which shows the correlation of the setting power factor and output suppression avoidance rate in the simulation of Example 1 of this invention. It is the distribution graph figure for every house of the output suppression amount and reactive power in the simulation of Example 1 of this invention, (a) A figure shows the amount of output suppression, (b) The case of reactive power is shown. It is a graph which shows the determination coefficient calculation result in the simulation of Example 1 of this invention, (a) figure, (b) figure, (c) figure shows the case where a coefficient is changed mutually, respectively. It is an image figure of the output suppression generation | occurrence | production in a power distribution system.

DESCRIPTION OF SYMBOLS 1 Substation 2 High voltage distribution line 3 Transformer on pole 4 Low voltage distribution line 5 Housing 6 PV system 7 PCS 8 Load 9 Server 10 PCS terminal voltage

Claims (3)

In an area where photovoltaic power generation devices are connected to a plurality of consumers in one power distribution system, the PCS of the consumer having the photovoltaic power generation device is prevented from deviating from the voltage management value when the voltage rises. Therefore, the PCS end voltage of all customers in a region at a certain time was measured, and the difference between the PCS end voltage of the consumer who showed the highest voltage and the voltage management value was calculated, and the highest voltage was shown. The set value of the PCS of the customer is set to the same value as the voltage control value, the set value of the PCS of the other customer is set to the value obtained by adding the difference to each measured voltage, and the set value of the PCS is set to each customer. An output suppression avoidance method at the time of voltage rise in a reverse power flow of a photovoltaic power generation system connected to multiple units, characterized in that it is set. In an area where photovoltaic power generation devices are connected to a plurality of consumers in one distribution system, the PCS of the consumer provided in the photovoltaic power generation system does not deviate from the voltage management value when the voltage can be increased. In order to do this, the PCS of each photovoltaic power generation system is connected to a server, and each PCS measures the PCS terminal voltage according to a command from the server, and transmits the measured voltage to the server. The difference between the PCS end voltage and the voltage management value of the consumer showing the highest PCS end voltage is calculated, and the set value of the consumer PCS showing the highest voltage is the same value as the voltage management value. A function of setting the PCS settling value for each consumer, using the set value of the PCS of the other consumer as a value obtained by adding the difference to the measured voltage, and transmitting the set voltage to each PCS. Have Each PCS is characterized by being configured to set the setting value transmitted from the server, the output suppression avoidance system when a voltage rise in the reverse flow of the multiple stage interconnection sunlight power generation system. When the set time or condition is satisfied, the server automatically instructs each PCS to measure the set value of each PCS, collects and calculates the measured voltage data of each PCS, The output suppression at the time of the voltage rise in the reverse power flow of the multi-unit connected photovoltaic power generation system according to claim 2, wherein the setting value of the PCS is set and transmitted to the control unit of each resettable PCS. Avoidance system.

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