JP5556289B2 - Distributed power supply and distributed power supply control method - Google Patents

Description

  The present invention relates to a distributed power supply and a distributed power supply control method, and more particularly to a distributed power supply and a distributed power supply control method for controlling an interconnection point voltage.

  In recent years, distributed power sources such as wind power generators and solar cells are connected to existing power distribution systems to supply power to consumers. Of the technical requirements for connecting such distributed power sources to the power grid, the Ministry of Economy, Trade and Industry It is formulated as “Guidelines for grid interconnection technical requirements” (for example, see Non-Patent Document 1).

  A distributed power source refers to a power generation facility installed near a demand place regardless of its power generation form, scale, and installer. Examples include solar power generation facilities and wind power generation facilities that use natural energy, engine power generation systems and gas turbine power generation systems that use fuel, fuel cells, waste power generation facilities, and biomass power generation facilities. Moreover, not only these but also what stores and discharges electric power and energy, such as a lead storage battery, a sodium sulfur battery (NAS battery), a flywheel, and a superconducting energy storage device (SMES), is included in the concept of the distributed power source.

  On the other hand, for electric utilities, the voltage of electricity to be supplied is stipulated as a value to be maintained by the Electricity Business Act and an Ordinance of the Ministry of Economy, Trade and Industry. The above guidelines provide measures to maintain the voltage of low-voltage consumers at an appropriate value. When there is a risk that the voltage of the low-voltage consumer will increase beyond the appropriate value due to reverse power flow from the distributed power source, the voltage is automatically adjusted by the reactive power control function or output control function of the distributed power source. It describes that measures are taken.

In such a distributed power source, a method has been proposed in which fluctuations in the interconnection point voltage caused by active power are suppressed by voltage compensation control based on impedance estimation (see, for example, Patent Document 1). Further, in such a control method, the control is performed optimally on the assumption that the voltage of the distribution system before the distributed power supply interconnection is managed to be close to the reference value.
Furthermore, in the connection point voltage dependent control method, as shown in the relationship of Expression (10) and the predetermined connection point voltage upper limit value V _H (for example, 106 [V] to 107 [V]) as shown in FIG. And the lower limit value V _L (for example, 96 V), the reactive power Q _GV is changed to P _G × (tan φ) × (V−V _L ) in the equation (10) with respect to the change of the connection point voltage V. / (V _H −V _L ) is linearly changed. However, when the interconnection point voltage V exceeds the upper limit value VH, the reactive power Q _GV is calculated based on P _G × (tan φ) of the equation (10). When the constant power factor is fixed to 0.85, and the interconnection point voltage V is lower than the lower limit value V _L , the reactive power Q _GV is set to 0 in the equation (10), that is, the constant power factor = 1. Secure to the equivalent. FIG. 12 is a schematic diagram showing characteristics of a reactive power control method based on a system impedance-dependent method according to the prior art.

That is, the power factor cosφ is determined by the connection point voltage value, and the power factor decreases as it approaches the upper limit value of the connection point voltage. When the connection point voltage is equal to or higher than the upper limit value, the power factor is fixed at the lower limit value. .
Equation (10), _12, the lower limit of the _{Q GV} reactive power, _{V L} is linking point voltage, the upper limit of _{V H} is linking point voltage, V is the interconnection point voltage value, _{P G} is the active power , Φ is the phase at the power factor cos φ. Furthermore, a lower limit value and an upper limit value are set for the system impedance.

Japanese Patent Laid-Open No. 2007-300784 JP 2009-207225 A

Grid interconnection technical requirement guidelines for ensuring power quality (Agency for Natural Resources and Energy)

  However, in the prior art of Patent Document 1, the voltage of the distribution system before the distributed power connection is optimized on the assumption that it is managed to be close to the reference value. There may be a case where the interconnection point voltage is not in the vicinity of the reference value (for example, 105V) and has already been increased to 106V to 107V. In such cases, mainly using the connection point voltage-dependent control method, the reactive power output is fixed at the lower limit of the power factor, and there is a possibility that the control performance will be lost when the voltage rises further. There was a problem that there was.

  Further, in the conventional techniques of Patent Document 1 and Patent Document 2, in the voltage compensation control method based on impedance estimation, it is required to accurately estimate the impedance, so that a large load is applied to the arithmetic unit for performing the arithmetic processing. There was a problem. Furthermore, in the prior art of Patent Document 1, when the upper limit value or the lower limit value of the impedance is reached at the interconnection point voltage, the reactive power output sticks to and is fixed to the lower limit value of the power factor regardless of the amount of power generation. There was a problem.

  The present invention has been made in view of the above problems, and when the voltage is high due to system side factors, the reactive power output by the distributed power source does not stick to the limiter limit value. It is an object of the present invention to provide a distributed power source and a distributed power source control method for performing compensation.

  In order to achieve the above object, a distributed power source according to the present invention includes a power generation unit that generates active power and reactive power and outputs the active power and reactive power to a connection point, a voltage detection unit that detects a connection point voltage, and the connection An output power instruction generating unit that generates an instruction to reduce the power output to the point to the first predetermined power generation amount, and the first power generation amount at the first predetermined power generation amount with respect to the first interconnection point voltage at the rated power or maximum power A first voltage fluctuation value that is a difference between two interconnection point voltages and a second voltage fluctuation value that is a difference between the fourth interconnection point voltage at the first predetermined power generation amount with respect to the third interconnection point voltage at an arbitrary time. And a control unit that controls the power generation unit based on the reactive power corresponding to the second predetermined power factor.

  In the distributed power supply according to the present invention, the control unit obtains a third interconnection point voltage at the arbitrary time, reduces the generated power at the arbitrary time to the first predetermined power generation amount, and performs the first predetermined power generation. The second voltage fluctuation value may be calculated by obtaining a fourth interconnection point voltage at the time of power generation and calculating a difference of the fourth interconnection point voltage with respect to the third interconnection point voltage. Good.

  Further, in the distributed power source of the present invention, the control unit obtains a first interconnection point voltage at the rated power or maximum power, and lowers the rated power or maximum power to the first predetermined power generation amount, The first voltage fluctuation value is calculated by obtaining a second interconnection point voltage at the first predetermined power generation amount and calculating a difference of the second interconnection point voltage with respect to the first interconnection point voltage. You may do it.

  Further, in the distributed power source according to the present invention, the control unit includes the predetermined rated power or maximum power, the generated power at the arbitrary time, the third interconnection point voltage, and the fourth interconnection. The first voltage fluctuation value may be estimated using a point voltage.

  In the distributed power supply of the present invention, the frequency of calculating the second voltage fluctuation value is higher than the frequency of acquiring the fourth interconnection point voltage, and the frequency of acquiring the fourth interconnection point voltage is the first frequency. You may make it more than the frequency which calculates 1 voltage fluctuation value.

  Further, in the distributed power supply according to the present invention, the control unit may be configured such that when the second voltage fluctuation value is greater than 0 and the second voltage fluctuation value is less than the first voltage fluctuation value, Generating a reactive power based on a second predetermined power factor, the first interconnection point voltage, the second interconnection point voltage, the third interconnection point voltage, and the fourth interconnection point voltage, and generating the electric power; When the second voltage fluctuation value is greater than the first voltage fluctuation value, the reactive power based on the active power and the second predetermined power factor is generated to control the power generation unit, When the second voltage fluctuation value is less than 0, 0 reactive power may be generated to control the power generating unit.

Further, in the distributed power supply according to the present invention, the control unit is configured such that when the second voltage fluctuation value is greater than 0 and the second voltage fluctuation value is less than the first voltage fluctuation value, the active power P _G Tan φ based on the second predetermined power factor, the first interconnection point voltage V _m , the second interconnection point voltage V _0m , the third interconnection point voltage V, and the fourth interconnection point voltage V _0. The reactive power based on the relational expression P _G × (tan φ) × (V−V ₀ ) / (V _m −V _0m ) is generated to control the power generator, and the second voltage fluctuation value is If 1 greater than the voltage variation value, the active power P _G and the second predetermined consisting tan [phi based on power factor equation P _G × (tan [phi) and the generated reactive power based controls said power generation unit When the second voltage fluctuation value is less than 0, the reactive power is generated by generating 0 reactive power. It may be controlled raw unit.

  In the distributed power supply of the present invention, the control unit performs control until the absolute value of the second voltage fluctuation value falls within a third predetermined range, or the reactive power is generated by the second power generation output. Control may be performed until a value based on a predetermined power factor is reached.

In the distributed power supply of the present invention, the third predetermined range may be based on the accuracy of voltage measurement of the voltage detector or the accuracy of current measurement.

Further, in the distributed power source according to the present invention, the control unit estimates a system impedance of the power system, calculates the effective power, a ratio of a resistance component and a reactance component of the system impedance estimation value, and the system impedance estimation value. A predetermined binary value RBX _L , RBX _H (where RBX _L is smaller than RBX _H ) related to the ratio of the resistance component and the reactance component, and a first reactive power Q _GRX based on the second predetermined power factor; Second power based on active power, estimated system impedance of the power system, predetermined binary values Z _L and Z _H (where Z _L is smaller than Z _H ), and the second predetermined power factor power _{Q GZ} and the interconnection point voltage, the active power, the interconnection point voltage for a given binary _V L, _{V H} (provided that, _{V L} is less than _{V H)} A third reactive power Q _GV based on fine said second predetermined power factor, the interconnection point voltage, the active power, the rated power or the maximum power, the first communication system point voltage, the second communication system point A fourth reactive power Q _GΔV based on the voltage, the third interconnection point voltage, the fourth interconnection point voltage, and the second predetermined power factor, and a weighting factor K ₁ for the first reactive power Q _GRX , using a weighting coefficient _{K 2} for said second reactive power _{Q GZ,} the weighting factor _{K 3} for the third reactive power _{Q GV,} the weighting coefficient _{K 4} for the fourth reactive power _{Q JiderutaV,} the reactive power based on You may make it control.

In the distributed power source according to the present invention, in the distributed power source connected to at least one of a plurality of distributed power sources, a high-voltage line, and a low-voltage line, the control unit includes at least an overhead of the high-voltage line or the low-voltage line. Based on one of the span length that is the cumulative length of the transmission line, the frequency of change of the system configuration including the distributed power source, or the margin for the upper limit voltage value of the normal system voltage before interconnection The weighting coefficient K ₁ , the weighting coefficient K ₂ , the weighting coefficient K ₃ , and the weighting coefficient K ₄ may be determined.

In the distributed power supply according to the present invention, the control unit estimates a system impedance Z of the power system, and a ratio R between a resistance component R and a reactance component X of the active power P _G and the system impedance estimation value Z. / X, a predetermined binary value RBX _L , RBX _H (where RBX _L is smaller than RBX _H ) relating to the ratio R / X and a first relational expression (6) based on the second predetermined power factor cosφ The reactive power _QGRX , the active power P _G , the system impedance estimation value Z of the power system, the predetermined binary values Z _L and Z _H related to the system impedance (where Z _L is smaller than Z _H ) and the second a second reactive power Q _GZ based on relation of a predetermined power factor cos [phi (7), the interconnection point voltage V, the effective power P _G, given regarding the interconnection point voltage 2 value V _{L, H} (However, _{V L} is _{V H} less than) and the third reactive power _{Q GV} based on the relational expression of a second predetermined power factor cos [phi (8), the interconnection point voltage V, the effective power P _G , the rated power or maximum power P _m , the first connection point voltage V _m , the second connection point voltage V _0m , the third connection point voltage V, the fourth connection point voltage V ₀ , And the fourth reactive power Q _GΔV based on the relational expression (9) consisting of the second predetermined power factor cos φ, the weighting coefficient K ₁ for the first reactive power Q _GRX, and the weighting for the second reactive power Q _GZ a coefficient K _2, the weighting factor K ₃ for the third reactive power Q _GV, the weighting coefficient K ₄ for the fourth reactive power _Q GΔV, may be controlled by the use of a reactive power based on.

  In order to achieve the above object, in a distributed power supply control method for a distributed power supply, a power generation unit generates an active power and a reactive power and outputs them to a connection point, and a voltage detection unit includes a connection A voltage detection step for detecting a point voltage, an output power instruction generation unit for generating an instruction for reducing the power output to the interconnection point to a first predetermined power generation amount, and a control unit, The first voltage fluctuation value, which is the difference between the second interconnection point voltage at the first predetermined power generation amount with respect to the first interconnection point voltage at the rated power or maximum power, and the third interconnection point voltage at an arbitrary time A control step of controlling the power generation unit based on a second voltage fluctuation value that is a difference between the fourth interconnection point voltages at the first predetermined power generation amount and the reactive power corresponding to a second predetermined power factor. It is characterized by comprising.

  According to the present invention, and in the distributed power supply and the distributed power supply control method, when the voltage is high due to system-side factors, the reactive power output by the distributed power supply does not stick to the limiter limit value. Compensation can be performed.

It is a systematic diagram of the power distribution equipment which concerns on 1st Embodiment of this invention. It is a schematic diagram for explaining a fluctuation suppression principle of interconnection point voltage V by the reactive power Q _G according to the embodiment. It is a figure explaining the variation | change_quantity control of the connection point voltage which concerns on the same embodiment. 3 is a flowchart of voltage compensation control according to the embodiment. It is a flowchart of the voltage compensation control which concerns on 2nd Embodiment. It is a flowchart of the voltage compensation control in 3rd Embodiment. It is a figure explaining the weighting coefficient which concerns on 4th Embodiment. It is a figure explaining the determination conditions and determination criteria of the weighting coefficient which concern on the same embodiment. It is a flowchart of an example of the selection method of the weighting coefficient which concerns on the embodiment. It is an example of the combination of the weighting coefficient which concerns on the same embodiment. It is another example of the combination of the weighting coefficient which concerns on the same embodiment. It is a schematic diagram which shows the characteristic of the control method of the reactive power by the system | strain impedance dependence system which concerns on a prior art.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. In addition, this invention is not limited to the embodiment which concerns, A various change is possible within the range of the technical thought.

[First Embodiment]
FIG. 1 is a system diagram of a power distribution facility according to the first embodiment of the present invention. The present embodiment relates to a power distribution facility including a distributed power source PW1 that generates and controls reactive power using maximum voltage fluctuation and voltage fluctuation.

  In FIG. 1, symbol S is a distribution substation, C1 is a high voltage distribution line, T1 and T2 are distribution transformers (post transformers), C2 is a low voltage distribution line, PW1 is a distributed power source, and L is a load. . The distribution substation S is connected to the primary side of the distribution transformers T1 and T2 via the high-voltage distribution line C1. The high-voltage distribution line C1 transmits high-voltage power (for example, 6600 [V]) output from the distribution substation S to the distribution transformers T1 and T2. The distribution transformers T1 and T2 convert the high voltage power supplied via the high voltage distribution line C1 into low voltage power of, for example, 100 [V] or 200 [V], and supply the low voltage distribution line C2. The low-voltage distribution line C2 is provided between the distribution transformers T1 and T2 and the load L, and supplies low-voltage power to the load L.

  Here, the distribution substation S, the high-voltage distribution line C1, the distribution transformers T1 and T2, and the low-voltage distribution line C2 constitute an existing distribution system laid in a network in the city. On the other hand, the distributed power source PW1 is connected to the low-voltage distribution line C2 at the interconnection point, and supplies low-voltage power to the load L in linkage with the existing distribution system. Moreover, the load L has illustrated all the loads connected to the existing power distribution system.

As shown in FIG. 1, the distributed power source PW1 includes a voltmeter 1, an ammeter 2, a detected power calculation unit 3, an output power determination unit 4, an optimum output power calculation unit 5, and a storage unit as main functional components. 6, an output current setting unit 7, an output current control unit 8, an inverter 9, a DC power supply 10, and an interconnection reactor 11 are provided.
The voltmeter 1 detects an instantaneous value of the voltage (connection point voltage V) at the connection point of the low-voltage distribution line C <b> 2 and outputs it to the detected power calculation unit 3. The ammeter 2 detects an instantaneous value of the output current of the distributed power source PW1 and outputs it to the detected power calculation unit 3.

Based on the instantaneous value of the voltage at the connection point input from the voltmeter 1 and the instantaneous value of the output current input from the ammeter 2, the detected power calculation unit 3 is output from the distributed power source PW1 to the connection point. Output power (that is, active power P _G and reactive power Q _G ) is calculated. The detected power calculation unit 3 outputs the calculated output power to the output power determination unit 4 and the optimum output power calculation unit 5 as detected power, and the instantaneous value of the voltage at the interconnection point input from the voltmeter 1 Based on the above, the effective value of the voltage at the connection point is calculated, and the calculated effective value of the connection point voltage (connection point voltage V) is output to the optimum output power calculation unit 5. Further, the detected power calculation unit 3 calculates the connection point voltage V _m at the rated power (or maximum power) P _m , and the output power determination unit 4 determines from the rated power (or maximum power) P _m to the generated power 0. calculating the interconnection point voltage V _om in after lowering calculates the interconnection point voltage V at the power P _G any time, calculated interconnection point voltage V, interconnection node voltage V _m, interconnection node voltage V _om and rated power (or maximum power) P _m are output to the optimum power calculation unit 5.

Output power determination unit 4 is input detected power input from the detection power calculation section 3, the input detected power is equal to or a rated power (or the maximum power) P _m. When it is determined that the input detected power is the rated power (or maximum power) P _m , the output power determination unit 4 gives an instruction to reduce the generated power to 0 at a predetermined power interval and a predetermined time interval. Output to the output setting unit 7. Further, the output power determination unit 4 calculates the interconnection point voltage V _om when the detected power calculation unit 3 has the generated power 0, and then again reaches the rated power (or maximum power) P _m for a predetermined power interval and a predetermined time. An instruction to increase at intervals is output to the output setting unit 7. The predetermined power interval and the predetermined time interval are, for example, a power interval of 10% of the maximum power P _{m and} an interval of 1 second, that is, the rated power (or maximum power) P _{m is} reduced from the rated power (or maximum power) P _m to 0 in 10 seconds. In 10 seconds, the generated power is increased from 0 to the rated power (or maximum power) _Pm to 0.
On the other hand, when it is determined that the input detected power is not the rated power (or maximum power) P _m , the output power determination unit 4 continues the measurement and calculation of the output of the detected power calculation unit 3.

The optimum output power calculation unit 5 detects the detected power (active power P _G and reactive power Q _G ), the connection point voltage V, the connection point voltage V _m , and the connection point voltage V _om input from the detection power calculation unit 3. and the rated power (or the maximum power) is stored by writing P _m in the storage unit 6. Further, the optimum output power calculation unit 5 includes a connection point voltage V, an active power P _G , a reactive power Q _G and a power factor lower limit value, a connection point voltage V _m , and a connection point stored in the storage unit 6. The voltage V _om and the rated power (or maximum power) P _m are read out, and the read connection point voltage V, active power P _G , reactive power Q _G and power factor lower limit value, connection point voltage V _m , connection point Based on the voltage V _om and the rated power (or maximum power) P _m or the like, the output power (active power P _G and reactive power Q _G ) of the inverter 9 is output to the output current setting unit 7 as a power command value.
The power instruction value is composed of a reactive power command value for instructing the active power command value and the reactive power Q _G instructing active power P _G to be output from the inverter 9. The lower limit of the power factor, which defines the upper limit of the reactive power Q _G output from the inverter 9, is a value that is acceptable existing distribution system (e.g., 0.85). In addition, the active power command value needs to be consistent with the generated power of the DC power supply 10. Furthermore, when generating the reactive power command value, the optimum output power calculation unit 5 estimates the system impedance Z including the existing power distribution system and its higher system using a predetermined estimation method. Then, the optimum output power calculation unit 5 calculates the estimated value of the system impedance Z, the lower limit value of the power factor, the connection point voltage V _m , the connection point voltage V _om , the connection point voltage V, and the rated power (or maximum power). based on the P _m or the like, can be suppressed to a minimum the variation of the interconnection point voltage V when the output active power P _G in the manner described below to the interconnection point via the interconnection reactor 11 from the inverter 9, and the inverter The reactive power Q _G that satisfies both of the maximum output capacities of 9 can be calculated as an optimum value. Then, the optimal output power calculating unit 5, a reactive power command value for instructing the output of the optimum value of the reactive power Q _G calculated is output to the output current setting unit 7.

The storage unit 6 includes the detected power (active power P _G and reactive power Q _G ), the connection point voltage V, the connection point voltage V _m , the connection point voltage V _om, and the rating that are input from the optimum output power calculation unit 5. The power (or maximum power) _Pm is stored. Moreover, the memory | storage part 6 has memorize | stored the lower limit of the power factor beforehand as one of the control information.

The output current setting unit 7 receives a power command value (active power command value and reactive power command value) output from the optimum output power calculation unit 5, generates a current command value based on the input power command value, The generated current command value is output to the output current control unit 8.
The output current control unit 8 generates a control signal for controlling the inverter 9 based on the current command value output from the output current setting unit 7, for example, a PWM (Pulse Width Modulation) signal, and outputs the control signal to the inverter 9.
The inverter 9 converts the DC voltage supplied from the DC power source 10 into an AC voltage by switching based on a control signal generated by the output current control unit 8. Further, the inverter 9 adjusts the voltage difference and the phase difference between both ends of the reactor 11 to determine the load current sharing.

The DC power supply 10 is a solar cell, for example, and outputs a predetermined DC voltage to the inverter 9.
The interconnected reactor 11 is a reactor (a coil in which an insulated wire is spirally wound), and is provided at the output end of the inverter 9 to provide inductance.
Note that the DC power supply 10 depends on the amount of light emitted from the sun, for example, by the generated power. Therefore, the inverter 9, can not be output active power P _G which is controlled to a constant value over a long period of time to the interconnection point, it outputs the active power that is constantly adapted to the power generated by the DC power supply 10 become. That is, distributed power PW1 in power distribution equipment can not control the active power P _G to a constant value, and outputs the active power P _G which varies randomly depending on the generated power of the DC power source 10 to the interconnection point.

As described above, the distributed power source PW1 constitutes power generation means in which the inverter 9, the DC power source 10, and the interconnection reactor 11 generate the active power P _G and the reactive power Q _G and output them to the connection point. . The voltmeter 1 ammeter 2, detection power calculation section 3, the optimum output power calculating unit 5, a storage section 6, the output current setting unit 7 and the output current control unit 8, interconnection points due to active power P _G calculated on the basis of reactive power Q _G so as to suppress the fluctuation of the voltage V to the system impedance Z, constitute a control means for controlling the power generating means to generate the reactive power Q _G. Such a distributed power source PW1 is a characteristic component of the power distribution facility.
The voltage generating unit is configured by an inverter 9, a DC power supply unit 10, and a grid reactor 11. The voltage detecting unit is configured by a voltmeter 1, an ammeter 2, and a detected power calculating unit 3, and an output power instruction generating unit. Includes an optimum output power calculation unit 5 and a storage unit 6, and the control unit includes an output power determination unit 4, an output current setting unit 7, and an output current control unit 8.

Next, the operation of the power distribution equipment configured as described above will be described in detail. In this power distribution facility, the distributed power source PW1 and the existing power distribution system work together to supply power to the load L. Linking point voltage V at the interconnection point between the dispersed type power supply PW1 and existing distribution system, but generally will vary depending on the active power P _G which is output from the distributed power source PW1, the distributed power PW1 of the power distribution facility may, itself outputs to the linking point by setting the reactive power Q _G so as to suppress the fluctuation of interconnection point voltage V caused by the active power P _G to be output to the interconnection point .

Figure 2 is a schematic diagram for explaining a fluctuation suppression principle of interconnection point voltage V by the reactive power Q _G in this embodiment. In this schematic diagram, the system impedance Z including the distribution system and its upper system is “R + jX”, the back voltage of the system is “E”, the power output from the distributed power source PW1 is “P _G + jQ _G ”, The load power consumed by the load L from the system point is “P + jQ”. Of the load power P + jQ, “P” indicates load effective power, and “Q” indicates load reactive power. Although the system impedance Z includes the impedance of the upper system, in reality, the impedance of the distribution system occupies most of the system, so that the back voltage E of the system is substantially equal to the output voltage of the distribution substation S.

  In this power distribution facility, the following approximate expression (1) is established with each value as a variable or constant.

V _drop = _EV
= R (P−P _G ) + X (Q−Q _G )
= (R × P + X × Q) - (R × P G + X × Q G) ··· (1)

The approximate expression (1), the voltage drop V _drop1 the voltage drop _{V drop} of the system is due to variation of the load L and (= R × P + X × Q), the active power _{P G} and disable output from the distributed power source PW1 It _shows that the voltage drop V _drop2 (= R × P _G + X × Q _G ) caused by the power Q _G.

That is, the voltage drop _{V Drop2} due to active power _{P G} and the reactive power _{Q G} of the dispersed power source PW1, by optimizing the reactive power _{Q G} of the dispersed power source PW1, i.e. the conditional expression: R × _P G + X It is possible to minimize by setting the reactive power Q _G to satisfy × Q _G = 0. This voltage drop V _Drop2 are those caused by active power P _G is existing that flows into the power distribution system and the active power P _G distributed power PW1 is changed.

Next, the voltage compensation operation will be described with reference to FIGS. 1 and 3 to 4. FIG. 3A and FIG. 3B are diagrams for explaining the change control of the interconnection point voltage in the present embodiment. FIG. 4 is a flowchart of voltage compensation control in the present embodiment. Also, the difference between FIG. 12 of the prior art and FIG. 3B is that the vertical axis is the connection point voltage fluctuation ΔV _G , that is, FIG. 3B shows the connection point potential fluctuation amount with respect to the reactive power Q _G. a [Delta] V _G, indicates that the reactive power output varies according to the interconnection point potential fluctuation amount [Delta] V _G.

First, in FIG. 3A, description will be made assuming that the distributed power source PW1 operates on the straight line A. First, the output power determination unit 4 determines whether or not the time T1 has elapsed since the previous execution of steps S3 to S6 (step S1). When the time T1 has elapsed since the previous execution of steps S3 to S6 (step S1; Yes), the process proceeds to step S3. When the time T1 has not elapsed since the previous step S3 to step S6 (step S1; No), the output power determination unit 4 has elapsed the time T2 since the previous step S7 to step S9. It is determined whether or not (step S2). When time T2 has elapsed since the previous execution of steps S7 to S9 (step S2; Yes), the process proceeds to step S7, and when time T2 has not elapsed since the previous execution of steps S7 to S9 (Step S2; No), the process proceeds to Step S10. As a result of the determination in step S1, when the time T1 has elapsed since the previous execution of steps S3 to S6, the output power determination unit 4 acquires the output of the detected power calculation unit 3, and the output power is the rated power. It is determined whether (or maximum power) P _m (step S3). As a result of the determination, if the output power is not a rated power (or the maximum power) _{P m} (Step S3; No), the process proceeds to step S2.
As a result of the determination, if the output power is the rated power (or the maximum power) P _m (Step S3; Yes), the output power determination unit 4 outputs an instruction to decrease the amount of power generation to zero output setting unit 7. The detection power calculation unit 3 calculates the interconnection point voltage V _m corresponding to the rated power P _m.

Next, the output current setting unit 7 generates a current command value based on the instruction to reduce the input power generation amount to 0, and based on the generated current command value, the output current control unit 8, the inverter 9, and the interconnection reactor 11. The electric power generation amount output to the connection point via 0 is reduced to 0 (step S4, FIG. 3 (a) P _G = 0, V _G = V _om ). Note that when dropping the power generation amount from 0 to rated power (or the maximum power) P _m, for example, go down over 10 seconds by 10% from the rated power (or the maximum power) P _m per second.
Next, the detected power calculation unit 3 calculates the interconnection point voltage V _om corresponding to the generated power = 0, and calculates ΔV _m = V _m −V _om (step S5).

After calculating the interconnection point voltage V _om corresponding to the generated power = 0, the detected power calculation unit 3 outputs an instruction to return the power generation amount from 0 to the rated power (or maximum power) P _m again to the output setting unit 7. .
Next, the output current setting unit 7 generates a current command value based on an instruction to return the input power generation amount to the rated power (or maximum power) _Pm , and the output current control unit 8 based on the generated current command value. , inverter 9, the power generation amount of rated power through the interconnection reactor 11 is outputted to the connecting point (or the maximum power) back to P _m (step S6). Incidentally, when the power generation amount back from 0 to the rated power (or the maximum power) P _m, for example, go raised over 10 seconds by 10% with respect to the rated power (or the maximum power) P _m per second.
Moreover, the process of step S4-step S6 is performed by time T1 space | interval by determination of step S1, for example, is performed about once a day during the day with much power consumption.

Next, after the execution of step S6 or as a result of the determination in step S2, when the time T2 has elapsed since the previous execution of steps S7 to S9, the power usage of the entire distribution facility in FIG. 1 changes. In FIG. 3A, the distributed power source PW1 is assumed to operate on the straight line B.
First, the detection power calculation unit 3 calculates the interconnection point voltage V corresponding to the generated power P _G at any time.
Next, the output power determination unit 4 outputs an instruction to lower the power generation amount to 0 to the output setting unit 7. Next, the output current setting unit 7 generates a current command value based on the instruction to reduce the input power generation amount to 0, and based on the generated current command value, the output current control unit 8, the inverter 9, and the interconnection reactor 11. The electric power generation amount output to the connection point via 0 is reduced to 0 (step S7, FIG. 3 (a) P _G = 0, V _G = V ₀ ). Note that when dropping the power generation amount from 0 to generated power P _G any time, for example, go down over 10 seconds by 10% from the power P _G every second.
Next, the detected power calculation unit 3 calculates an interconnection point voltage V ₀ corresponding to power = 0 (step S8).

After calculating the interconnection point voltage V ₀ corresponding to generation power = 0, the detection power calculation section 3 outputs an instruction to the output setting unit 7 to return the generated power P _G power generation amount from 0 again.
Then, the output current setting unit 7 generates a current command value based on an instruction to return the power generation amount input to generated power P _G, the output current control unit 8 based on the generated current command value, the inverter 9, communication returning the power generation amount is outputted to the connecting point via a system reactor 11 to the generator power P _G (step S9). Incidentally, when the power generation amount from 0 back to the generator power P _G, for example, go raised over by 10% 10 seconds to the generator power P _G every second.
Moreover, the process of step S7-step S9 is performed by time T2 interval by determination of step S2, for example, is performed about once every several minutes.

Then, after returning the power generation amount of generated power P _G in step S9, or if the result of determination in step S2, when the time T2 since the implementation of the previous step S7~ step S9 has not elapsed, the detection power calculation part 3 calculates the interconnection point voltage V corresponding to the generated power P _G arbitrary time (step S10).
After calculating the interconnection point voltage V corresponding to the generated power P _G any time, the detection power calculation section 3 uses the interconnection point voltage V and V _0, which is calculated, the voltage change value [Delta] V = V-V ₀ Calculate (step S11).
Next, the optimum output power calculation unit 5 calculates the reactive power output using Expression (2) based on the determination in step S12.

When ΔV <0 (step S12; ΔV <0), the optimum output power calculation unit 5 calculates Q _GΔV = 0 (step S13).
When 0 <ΔV <ΔV _m (step S12; 0 <ΔV <ΔV _m ), the optimum output power calculation unit 5 calculates Q _GΔV = P _G × (tan _φ ) × ΔV / ΔV _m (step S14).
When ΔV <ΔV _m (step S12; ΔV <ΔV _m ), the optimum output power calculation unit 5 calculates Q _GΔV = P _G × (tan _φ ) (step S15).
Next, the optimum output power calculation unit 5 outputs the calculated reactive power output Q _GΔV to the output current setting unit 7, and the output current setting unit 7 sets the current command value based on the input reactive power output Q _GΔV. It produces | generates and it outputs to a connection point via the output current control part 8, the inverter 9, and the interconnection reactor 11 based on the produced | generated electric current command value.
Note that a series of processing from the start to the end of the flowchart of FIG. 4 is performed at time T3 intervals, for example, once every several seconds. As a result, the processing of step S10 to step S15 is performed at time T3 intervals. The length of time T1 is longer than the length of time T2, and the length of time T2 is longer than the length of time T3. The time T1 is, for example, about one day, the time T2 is, for example, about several minutes, and the time T3 is, for example, about several seconds.

In the conventional technique, when the voltage is high due to system side factors, the reactive power output by the distributed power supply may stick to the limiter limit value, and the voltage rise caused by the distributed power supply PW1 cannot be compensated effectively. There was also. According to the present embodiment, the optimum output power calculation unit 5 uses the reactive power Q _GΔV based on the connection point voltage fluctuation to generate the reactive power Q _G and controls the voltage compensation.
That is, as described in the first embodiment, the maximum value ΔV _m of the voltage fluctuation due to the output of the dispersion device PW1 is measured or estimated in advance, the power factor is determined by the voltage fluctuation ΔV at an arbitrary time, and the voltage fluctuation ΔV is measured in advance. Alternatively, the reactive power Q _GΔV is generated so that the power factor decreases as the estimated maximum value is approached, and the amount of change in the interconnection point voltage is controlled, so that the voltage increase caused by the distributed power source PW1 can be effectively compensated.

In the present embodiment, the length of time T1 is set to about one day, the power generation amount is reduced to 0 at the rated power (or maximum power) P _m , and the frequency of calculating the interconnection point voltage V _0m of the power generation amount 0 is 1 Although the example performed once a day has been described, this frequency may be another frequency, for example, once every two days, etc., in accordance with the power fluctuation of the distribution system including the distributed power source PW1. Further, when the average value processing is performed on the electric power, the frequency of calculating the interconnection point voltage V _0m may be about once a month. Moreover, as several minutes the length of time T2, has been described an example in which once every several minutes the frequency of calculating the interconnection point voltage V ₀ is lowered to the power generation amount 0 from the output P _G any time, similar The frequency of calculating the interconnection point voltage V ₀ may be another frequency according to the power fluctuation of the distribution system including the distributed power source PW1, such as once every 10 minutes. Further, as a few seconds the length of time T3, constantly measures the interconnection point voltage V, has been described an example in which once the frequency of calculating the voltage variation ΔV in a few seconds, similarly the interconnection point voltage V ₀ The frequency to be calculated may be another frequency according to the power fluctuation of the power distribution system including the distributed power source PW1, such as once every 10 seconds.

As described above, the maximum voltage fluctuation ΔV _m at the rated power is calculated, the voltage fluctuation ΔV is calculated at an arbitrary time, and the reactive power output is calculated using the calculated maximum voltage fluctuation ΔV _m and the voltage fluctuation ΔV. Therefore, even when the voltage is high due to system side factors, it becomes possible to compensate for fluctuations in the interconnection point voltage so that the reactive power output from the distributed power source does not stick to the limiter limit value. .

[Second Embodiment]
Next, a second embodiment will be described using FIG. 1, FIG. 3, and FIG. FIG. 5 is a flowchart of voltage compensation control in the present embodiment. Note that the same processes as those in the first embodiment are denoted by the same step numbers and description thereof is omitted. The second embodiment, when the distributed power supply PW1 is unable to rated power (or the maximum power) P _m, to estimate the maximum voltage variation [Delta] V _m, is a method of performing voltage compensation.
In FIG. 3A, description will be made assuming that the distributed power source PW1 operates on the straight line A. The detection power calculation section 3, the rated power in the distributed power PW1 (or the maximum power) P _m is stored.

  First, the output power determination unit 4 determines whether or not the time T1 has elapsed since the previous execution of Step S3 to Step S107 or Step S3 to Step S6 (Step S101). If time T1 has elapsed since the previous execution of step S3 to step S107 or step S3 to step S6 (step S101; Yes), the process proceeds to step S3. When the time T1 has not elapsed since the previous step S3 to step S107 or step S3 to step S6 was performed (step S101; No), the output power determination unit 4 has performed the previous step S7 to step S9. It is determined whether or not the time T2 has elapsed (step S102). When the time T2 has elapsed since the execution of the previous step S7 to step S9 (step S102; Yes), the step S7 to step S11 are performed to calculate the voltage fluctuation ΔV, and the previous step S7 to step S9 is performed. When the time T2 has not elapsed since the execution (step S102; No), steps S10 to S11 are performed. In addition, operation | movement of step S102-step S11 is the same as operation | movement of step S2-step S11 of 1st Embodiment.

As a result of the determination in step S101, when the time T1 has elapsed since the previous execution of step S3 to step S107 or step S3 to step S6 (step S101; Yes), the output power determination unit 4 3 of the output acquired, the output power is determined whether the rated power (or the maximum power) P _m (step S3). Result of the determination, the output power is the rated power (or maximum power) when the _{P m} (Step S3; Yes), the output power determination unit 4, similarly to the first embodiment performs the step S4~ step S11, the maximum voltage The fluctuation ΔV _m and the voltage fluctuation ΔV are calculated by actual measurement.
As a result of the determination, if the output power is not a rated power (or the maximum power) P _m (Step S3; No), the output power determination unit 4 outputs an instruction to decrease the amount of power generation to zero output setting unit 7. Next, the output current setting unit 7 generates a current command value based on the instruction to reduce the input power generation amount to 0, and based on the generated current command value, the output current control unit 8, the inverter 9, and the interconnection reactor 11. The power generation amount output to the connection point via 0 is reduced to 0 (step S103). Note that when dropping the power generation amount from 0 to generated power P _G any time, for example, go down over 10 seconds by 10% from the power P _G every second.
Next, the detected power calculation unit 3 calculates a connection point voltage V _0m corresponding to power = 0 (step S104).

After calculating the interconnection point voltage V _{0 m} corresponding to generation power = 0, the detection power calculation section 3 outputs an instruction to the output setting unit 7 to return the generated power P _G power generation amount from 0 again.
Then, the output current setting unit 7 generates a current command value based on an instruction to return the power generation amount input to generated power P _G, the output current control unit 8 based on the generated current command value, the inverter 9, communication returning the power generation amount is outputted to the connecting point via a system reactor 11 to the generator power P _G (step S105). Incidentally, when the power generation amount from 0 back to the generator power P _G, for example, go raised over by 10% 10 seconds to the generator power P _G every second.
After returning the power generation amount of generated power P _G, detected power calculation unit 3 calculates the interconnection point voltage V corresponding to the generated power P _G any time (step S106).

Next, the detection power calculation section 3, interconnection communicating voltage V and the rated power (or the maximum power) and the corresponding interconnection connecting the voltage V _{0 m} that corresponds to the generated power 0 calculated for generated power P _G using P _m estimates the [Delta] V _m by linear interpolation using equation (3) (step S107).

ΔV _m = P _m × (V−V _{0 m} ) / P _G (3)

Next, steps S7 to S11 are performed.
Note that the processing of step S3 to step S107 or step S3 to step S6 is performed at time T1 intervals based on the determination of step S101, for example, about once a day during a day when power consumption is large, and step S7. The process in step S9 is performed at intervals of time T2 based on the determination in step S102, for example, once every several minutes.
Hereinafter, using the estimated [Delta] V _m with [Delta] V _m or step S107 which is calculated in step S5, the step S12~ step S15 in the first embodiment repeatedly, the optimal output power calculating unit 5, the calculated reactive power Q _GΔV is output to the output current setting unit 7. The output current setting unit 7 generates a current command value based on the input reactive power output Q _GΔV , and the output current control unit 8 and the inverter based on the generated current command value. 9. Output to the connection point via the interconnected reactor 11.
Note that a series of processing from the start to the end of the flowchart of FIG. 5 is performed at time T3 intervals, for example, once every few seconds. As a result, the processing of step S10 to step S15 is performed at time T3 intervals. The length of time T1 is longer than the length of time T2, and the length of time T2 is longer than the length of time T3. The time T1 is, for example, about one day, the time T2 is, for example, about several minutes, and the time T3 is, for example, about several seconds.
That is, only when it can not output the rated power (or the maximum power) _{P m,} if performed step S103~ step S107, to estimate the maximum voltage variation [Delta] V _m, it outputs the rated power (or the maximum power) _{P m,} the As in the first embodiment, the maximum voltage fluctuation ΔV _m is calculated by actual measurement (steps S4 to S6).

In the conventional technique, when the voltage is high due to system side factors, the reactive power output by the distributed power supply may stick to the limiter limit value, and the voltage rise caused by the distributed power supply PW1 cannot be compensated effectively. There was also. According to this embodiment, even when power generation cannot be performed with the rated power (or maximum rating) P _m , the detected power calculation unit 3 estimates the voltage fluctuation ΔV _m , and the optimum output power calculation unit 5 performs the connection described in the first example. The reactive power Q _G is generated using the reactive power Q _GΔV based on the system point voltage fluctuation to control the voltage compensation. That is, as described in the first embodiment, the maximum value ΔV _m of the voltage fluctuation due to the output of the dispersion device PW1 is measured or estimated in advance, the power factor is determined by the voltage fluctuation ΔV at an arbitrary time, and the voltage fluctuation ΔV is measured in advance. Alternatively, the reactive power Q _GΔV is generated so that the power factor decreases as the estimated maximum value is approached, and the amount of change in the interconnection point voltage is controlled, so that the voltage increase caused by the distributed power source PW1 can be effectively compensated.

In the present embodiment, the example in which the length of time T1 is set to about one day and the frequency of calculating the maximum voltage fluctuation ΔV _m by estimation or actual measurement is performed once a day has been described. Another frequency, for example, once every two days, etc. may be used in accordance with the power fluctuation of the distribution system including the power supply PW1. Further, when the power is averaged, the frequency of calculating the maximum voltage fluctuation ΔV _m by estimation or actual measurement may be about once a month.
Furthermore, since the value obtained by calculating the maximum voltage fluctuation ΔV _m by actual measurement is higher in accuracy than the value of the estimated maximum voltage fluctuation ΔV _m , in the determination of S101, the previous steps S4 to S6 are performed. When the maximum voltage fluctuation ΔV _m is acquired by the execution, T1 is a large value (for example, 10 days), and when the maximum voltage fluctuation ΔV _m is estimated by the previous execution of Steps S103 to S107, T1 is a small value. (e.g., 1 day) by a, it is also possible to increase the operation period of the distributed power PW1 by higher values of accurate maximum voltage variation [Delta] V _m.
Further, in the present embodiment, as several minutes the length of time T2, an example in which once the frequency of calculating the interconnection point voltage V ₀ is lowered to the power generation amount 0 from the output P _G any time in minutes As described above, the frequency at which the interconnection point voltage V ₀ is calculated in the same manner may be another frequency according to the power fluctuation of the distribution system including the distributed power source PW1, such as once every 10 minutes. Further, as a few seconds the length of time T3, constantly measures the interconnection point voltage V, has been described an example in which once the frequency of calculating the voltage variation ΔV in a few seconds, similarly the interconnection point voltage V ₀ The frequency to be calculated may be another frequency according to the power fluctuation of the power distribution system including the distributed power source PW1, such as once every 10 seconds.

As described above, when the dispersed power source PW1 is unable to rated power (or the maximum power) P _m, to estimate the maximum voltage variation [Delta] V _m, with a maximum of the voltage variation [Delta] V _m and the voltage variation [Delta] V estimated Reactive power output is calculated and output, so even if the voltage is high due to system-side factors, compensation for fluctuations in the interconnection voltage that prevents the reactive power output from the distributed power source from sticking to the limiter limit value is performed. It becomes possible.

[Third Embodiment]
Next, a third embodiment will be described with reference to FIG. 1, FIG. 3, and FIG. FIG. 6 is a flowchart of voltage compensation control in the present embodiment. Note that the same processes as those in the first embodiment are denoted by the same step numbers and description thereof is omitted. In the third embodiment, reactive power Q _GΔV is gradually injected, and a _limiter is applied when the voltage fluctuation ΔV is within a predetermined range or becomes reactive power Q _Gmax corresponding to the power factor 0.85 of the power generation output. This is a method of performing voltage compensation.

First, the detection power calculation unit 3 executes a step S1~ step S4, and calculates the interconnection point voltage V _m at the rated power (or the maximum power) P _m, the rated power (or the maximum power) when P _m The connection point voltage V _0m when the power generation amount is reduced to ₀ is calculated, and the maximum voltage fluctuation ΔV _m is calculated.
Next, the detection power calculation unit 3 executes a step S5~ step S9, calculates an interconnection point voltage V of the power generation electric power P _G any time, the power generation amount from the time of the generated power P _G any time 0 The connection point voltage V ₀ when it is dropped to is calculated, and the voltage fluctuation ΔV is calculated.
Next, in order to compensate the calculated voltage fluctuation ΔV, the optimum output power calculation unit 5 calculates reactive power Q _GΔV = P _G × (tan _φ ) × ΔV / ΔV _m (step S201).
Then, the calculated reactive power Q _GΔV is output to the output current setting unit 7, and the output current setting unit 7 generates a current command value based on the input reactive power Q _GΔV, and based on the generated current command value By outputting to the connection point via the output current control unit 8, the inverter 9, and the interconnection reactor 11, the reactive power Q _GΔV is injected into the distribution facility system (step S202).

Next, the optimum output power calculation unit 5 determines whether or not Q _GΔV is less than Q _Gmax (= P _G × (tan _φ )) (step S203).
If Q _GΔV is less than Q _{Gmax as} a result of the determination in step 203 (step S203; Yes), the detected power calculation unit 3 determines whether the absolute value of the voltage fluctuation ΔV (= V−V ₀ ) is equal to or less than a predetermined ε. It is determined whether or not (step S204). For example, ε is equivalent to the accuracy of the voltmeter 1, and ε = 1% when the accuracy of the voltmeter 1 is 1% of the rated voltage.
As a result of the determination in step S204, if the absolute value of the voltage fluctuation ΔV is not less than or equal to the predetermined ε (step S204; No), the process returns to step S8, and the absolute value of the voltage fluctuation ΔV is less than or equal to the predetermined ε. _{Alternatively} , the _process is repeated until Q _GΔV becomes _equal to or greater than Q _{Gmax as} a result of the determination in step S203.

If Q _GΔV is _equal to or greater than Q _{Gmax as} a result of the determination in step S203 (step S203; No), the optimum output power calculation unit 5 substitutes Q _Gmax for Q _GΔV (step S205). Step S203 is, when _{the Q JiderutaV} exceeds the reactive power _{Q Gmax} corresponding to the power factor 0.85 of the generator output _{P G,} which means that optimum output power calculating unit 5 multiplies the limiter _{Q Gmax} reactive power ing.
Next, as a result of the determination in step S204, the optimum output power calculation unit 5 determines that Q _GΔV when the absolute value of the voltage fluctuation ΔV is equal to or less than a predetermined ε, or a power factor 0.85 of the power generation output P _G after step S205. The reactive power Q _Gmax corresponding to is determined as the reactive power Q _GΔV (step S206). Then, the optimum output power calculation unit 5 generates a current command value based on the determined _QGΔV , and at the connection point via the output current control unit 8, the inverter 9, and the interconnection reactor 11 based on the generated current command value. By outputting, reactive power Q _GΔV is output to the distribution facility system.

In the conventional technique, when the voltage is high due to system side factors, the reactive power output by the distributed power supply may stick to the limiter limit value, and the voltage rise caused by the distributed power supply PW1 cannot be compensated effectively. There was also. According to the present embodiment, the optimum output power calculation unit 5 uses the reactive power Q _GΔV based on the interconnection point voltage fluctuation described in the first example, until the absolute value of the voltage fluctuation ΔV reaches a predetermined ε. Gradually output to the system and inject. That is, as described in the first embodiment, the maximum value ΔV _m of the voltage fluctuation due to the output of the dispersion device PW1 is measured or estimated in advance, the power factor is determined by the voltage fluctuation ΔV at an arbitrary time, and the voltage fluctuation ΔV is measured in advance. Alternatively, the reactive power Q _GΔV is generated so that the power factor decreases as the estimated maximum value is approached, and the amount of change in the interconnection point voltage is controlled, so that the voltage increase caused by the distributed power source PW1 can be effectively compensated.

In this embodiment, the example in which the maximum voltage fluctuation ΔV _m is measured and calculated in the same manner as in the first embodiment has been described. However, the value estimated by the same method as in steps S3 to S107 in the second embodiment. May be used.

  Further, in the present embodiment, an example in which the predetermined ε is equivalent to the accuracy of the voltmeter 1 has been described, but the predetermined ε may be equivalent to the accuracy of the ammeter 2, for example, or may be a predetermined value set in advance. good.

As described above, the reactive power Q _GΔV is gradually injected, and a voltage is applied by applying a limiter when the voltage fluctuation ΔV becomes within a predetermined range or the reactive power Q _Gmax corresponding to the power factor 0.85 of the power generation output. Since the compensation is performed, even when the voltage is high due to system side factors, it is possible to compensate for fluctuations in the interconnection point voltage in which the reactive power output from the distributed power source does not stick to the limiter limit value.

[Fourth Embodiment]
Next, a fourth embodiment will be described with reference to FIGS. 1 and 7 to 11. FIG. 7 is a diagram illustrating the weighting coefficient in the present embodiment. FIG. 8 is a diagram for explaining the weighting coefficient determination conditions and determination criteria in the present embodiment.

The applicant has, in JP 2009-207225, has filed a method of controlling the reactive power _{Q G} with a weighting factor as in equation (4).

Q _G = K ₁ × Q _GRX + K ₂ × Q _GZ + K ₃ × Q _GV (4)

However, K _{1 to} K ₃ are weighting coefficients of the reactive powers Q _GRX , Q _GZ , and Q _GV , and K ₁ + K ₂ + K ₃ = 1.

This embodiment is a method of controlling the reactive power Q _G by giving a weighting coefficient to the connection point voltage Q _GΔV shown in the first to third embodiments in addition to the weighting coefficient of the method of Japanese Patent Laid-Open No. 2009-207225. . In the present embodiment, the optimum output power calculating unit 5 is controlled based on the reactive power Q _G in equation (5).

Q _G = K ₁ × Q _GRX + K ₂ × Q _GZ + K ₃ × Q _GV + K ₄ × Q _GΔV (5)

_However, K 1 ~K _4, each reactive power _{Q GRX,} Q _GZ, are weighting coefficients of _{Q GV} and _{Q JiderutaV,} a _{K 1 + K 2 + K 3} + K 4 = 1.

That is, active power _{P G,} system impedance ratio R / X between the resistance component R and reactance X of the estimated value Z, consists of a lower limit value _{R BXL} and the upper limit value _{R BXH} and power factor cosφ relates ratio R / X following equation Reactive power Q _GRX based on (6) (that is, reactive power calculated using the reactive power control method proposed in Japanese Patent Application No. 2009-207225), active power P _G , system impedance estimation value Z of power system, system Reactive power Q _GZ based on the following relational expression (7) consisting of the lower limit value Z _L , the upper limit value Z _H and the power factor cosφ regarding the impedance Z (that is, using the system impedance dependent Z chameleon method proposed in Japanese Patent Application No. 2007-099677) and reactive power) calculated Te, interconnection point voltage V, active power P _G, a lower limit regarding interconnection node voltage V value V _L and the upper limit value V _H and the power factor c following relational equation (reactive power calculated using the words interconnection point voltage dependence reactive power control scheme proposed in Japanese Patent Application No. 2007-099677) reactive power _{Q GV} based on (8) consisting of Esufai, active power _{P G} , Interconnection point voltage V _m at rated power (or maximum power), interconnection point voltage V _0m when rated power (or maximum power) is reduced to power generation amount 0, generated power V at arbitrary time, at arbitrary time From the interconnection point voltage V ₀ and the power factor cos φ when the power generation amount is reduced to 0, the reactive power Q _GΔV based on the following relational expression (9) (that is, calculated using the reactive power control method according to the first embodiment) And the weighting coefficients K ₁ , K ₂ , K ₃ , and K ₄ (where K ₁ + K ₂ + K ₃ + K ₄ = 1) for each reactive power, the optimum output power calculation unit 5 set the optimal reactive power Q _G To.

Q _GRX is expressed as shown in Equation (6).

Incidentally, the ratio of R / X is a resistance component R and reactance X of the system impedance estimated value _Z, the upper limit of _{R BXH} are R / _{X, R BXL} upper limit of R / X, phi is the power factor cosφ phase It is. K ₁ is a weight for Q _GRX , and as shown in FIG. 7, the proportion of resistance R of system impedance estimated value Z is higher than reactance amount X as the ratio of lead-in wire is higher than that of high-voltage line and low-voltage line. The power Q _GRX increases. The system impedance estimated value Z is estimated by an existing method, for example, the method disclosed in Japanese Patent Application Laid-Open No. 2009-207225.
Further, Q _GZ is expressed as in Expression (7).

The system impedance estimated values Z and Z _H are upper limit values related to the system impedance estimated value Z, and Z _L is a lower limit value related to the system impedance estimated value Z. K ₂ is a weighting for Q _GZ , and as shown in FIG. 7, the reactive power Q _GZ increases as the system terminal increases, and the higher the absolute value of the total impedance regardless of the high-voltage line, low-voltage line, and lead-in line, the more invalid it becomes. The power Q _GZ increases.

Further, Q _GV is expressed as in Expression (8).

V _H is an upper limit value for the connection point voltage V, and V _L is a lower limit value for the connection point voltage V. K ₃ is a weight for Q _GV , and as shown in FIG. 7, the higher the interconnection point voltage, the higher the reactive power Q _GV becomes. When the voltage increase due to the output of the distributed power source is mostly, It is possible to compensate for the voltage rise caused by. However, when the voltage is high due to system side factors, the reactive power output by the distributed power source may stick to the limiter limit value, and the voltage increase caused by the distributed power source cannot be compensated effectively. In such a case, voltage compensation can be performed by increasing the specific gravity to the other weighting factors K ₁ , K ₂ , and K ₄ .

Further, Q _GΔV is expressed as in Expression (9).

K ₃ is a weighting for Q _GΔV , and as shown in FIG. 7, the reactive power Q _GΔV increases as the amount of change in the interconnection point voltage increases.

Further, as shown in FIG. 7, the weighting coefficients K ₁ and K ₂ are related to the voltage compensation technique for performing impedance estimation, and the weighting coefficients K ₃ and K ₄ are related to the voltage compensation technique depending on the voltage value. .

Next, an example of selecting a weighting coefficient will be described with reference to FIGS. FIG. 9 is a flowchart of an example of a weighting coefficient selection method according to the present embodiment. Further, in the storage unit 6, frequency configuration change frequency information, high-voltage line / low-voltage line length information, and margin information for the upper limit voltage of the normal system voltage before interconnection are written and stored in advance.
The optimum power calculation unit 5 reads information on the grid stored in the storage unit 6 (step S301), and extracts class 1 information, class 2 information, and class 3 information (step S302). Class 1 is information on the frequency of system configuration change, Class 2 is the length of high-voltage lines and low-voltage lines (the length of the overhead power transmission line, connecting the center of the support such as the steel tower from the starting point of the substation, etc. Class 3 is information on the margin for the upper limit voltage of the normal system voltage before interconnection.

As shown in FIG. 8, the weighting conditions for the weighting coefficients K _{1 to} K ₄ are different depending on the class. The criteria for determining the frequency of system configuration change in class 1 is based on the number of system configuration changes in the past year. If the number of system configuration changes in the past year is 2 or more, frequency = large, and once. If frequency = medium and 0 times, it is determined that frequency = small. Similarly, the condition for determining the length of the high-voltage line / low-voltage line of class 2 is as follows: when the length of the low-voltage line of the interconnection system is 100 [m] or longer, the length is 50 [m] to 100 [m]. In the case of m], it is determined that the travel length = medium, and in the case of less than 50 [m], the travel length = short. Furthermore, the condition for determining the margin with respect to the upper limit voltage of the normal system voltage that is Class 3 before the interconnection is, when the maximum value of the interconnection point voltage before the interconnection is less than 103 [V], the margin is large, In the case of 103 [V] to 105 [V], it is determined that the margin is medium, and in the case of 105 [V] or more, the margin is small.
Note that the weighting conditions for each of the weighting coefficients K _{1 to} K ₄ in FIG. 8 are examples, and the determination criteria, the type and number of classes, and combinations of weighting determination conditions (classification) and weighting coefficients are different. It may be a combination. Moreover, the frequency information of the system configuration change, the length information of the high-voltage line and the low-voltage line, and the margin information with respect to the upper limit voltage of the normal system voltage before interconnection are written and stored in advance in the storage unit 6 of the distributed power source PW1. Alternatively, it may be generated based on information obtained from the electric power company at the time of installation or measured information, and the generated information may be written and stored in the storage unit 6, or may be installed first. Each piece of information may be generated based on information from other distributed power sources, and the generated information may be written and stored in the storage unit 6.

Next, when the class 1 information is extracted in step S302, the optimum power calculation unit 5 determines whether the frequency of system configuration change is higher than a predetermined threshold (step S303). If the frequency of the system configuration change is higher than a predetermined threshold value (step S303; Yes), the optimum power computation section 5, the weighting coefficient _{K 1} and _{K 2,} the other weighting factor _{K 3} and much more allocation _{K 4} (Step S304). As an example, K ₁ = 0.5, K ₂ = 0.5, K ₃ = 0, K ₄ = 0.
Further, if the frequency of the system configuration change is lower than a predetermined threshold value (step S303; No), the optimum power computation section 5, the weighting coefficient _{K 3} and _{K 4,} the allocation from the other weighting coefficients _{K 1} and _{K 2} (Step S305). As an example, the optimum power calculation unit 5 selects K ₁ = 0, K ₂ = 0, K ₃ = 0.5, and K ₄ = 0.5 for each weighting coefficient.

Next, when class 2 information is extracted in step S302, the optimum power calculation unit 5 determines whether or not the length of the high-voltage line / low-voltage line is shorter than the length of the lead-in line (step S306). If a short route length is the length of the lead-in high-voltage lines and low pressure lines (step S306; Yes), the optimum power computation section 5, the weighting coefficient _{K 1,} more allocation than any other weighting coefficient _K 2 ~K ₄ (Step S307). As an example, the optimum power calculation unit 5 selects K ₁ = 1.0, K ₂ = 0, K ₃ = 0, and K ₄ = 0 for each weighting coefficient.
Also, if the route length of the high-voltage lines and low-pressure line is not shorter the length of the lead-in (Step S306; No), the optimum power computation section 5, the weighting coefficient _{K 2,} the other weighting coefficients _{K 1, K} 3, increasing the allocation from the K ₄ (step S308). As an example, the optimum power calculation unit 5 selects K ₁ = 0, K ₂ = 1.0, K ₃ = 0, and K ₄ = 0.5 for each weighting coefficient.

Next, when class 3 information is extracted in step S302, the optimum power calculation unit 5 determines whether or not the margin with respect to the upper limit voltage of the normal system voltage before interconnection is greater than or equal to a predetermined threshold value. (Step S309). If margin for the upper limit voltage of the constant of the system voltage before interconnection is equal to or larger than a predetermined threshold value (step S309; Yes), the optimum power computation section 5, the weighting coefficient K _3, other weighting factors K _1, The distribution is increased more than K ₂ and K ₄ (step S310). As an example, the optimum power calculation unit 5 selects K ₁ = 0, K ₂ = 0, K ₃ = 1.0, and K ₄ = 0 for each weighting coefficient.
Also, if the margin for the upper limit voltage of the constant of the system voltage before interconnection is less than the predetermined threshold value (step S309; No), the optimum power calculation unit 5, the weighting coefficient K _4, the other weighting factor The distribution is increased from K _{1 to} K ₃ (step S311). As an example, the optimum power calculation unit 5 selects K ₁ = 0, K ₂ = 0, K ₃ = 0, and K ₄ = 1.0 for each weighting coefficient.

The optimum power calculator 5 determines each of the weighting factors K _{1 to} K ₄ (step S312). The information regarding the system may have class 1 to class 3 in combination. In this case, the distribution of the weighting factors K _{1 to} K _{4 in} step S312 is determined based on the weighting factors selected in step S303, step S306, and step S309. As an example, weighting factors K ₁ and K ₂ are selected in step S303 (eg, K ₁ = 0.5, K ₂ = 0.5), and weighting factor K ₁ is selected in step S306 (eg, K ₁ = 1. 0), the case where the weighting coefficient K ₃ is selected (eg, K ₃ = 1.0) in step S309 will be described. In this case, the optimum power computation section 5, step S303, step S306, the value of the selected weighting coefficients in step S309, the calculated total sum for each weighting coefficient, further calculates the sum of the weighting factors _K 1 ~K ₄ To do.
As a result, K ₁ = 1.5, K ₂ = 0.5, K ₃ = 1.0, K ₄ = 0, and K (total) = 3.0 are calculated. Then, the optimum power calculation unit 5 divides each of the weighting coefficients K _{1 to} K ₄ by K (total) = 3.0, and K ₁ = 0.5, K ₂ = 0.17, K ₃ = 0 by division. .33, K ₄ = 0. In other words, the optimum power calculation unit 5 distributes the respective weighting factors K _{1 to} K ₄ so that K ₁ + K ₂ + K ₃ + K ₄ = 1.

  Further, in the flowchart of FIG. 9, in order to simplify the description, an example in which the determination is made by comparing with one predetermined threshold value in step S303 has been described. However, for example, there are two predetermined threshold values. Then, as shown in FIG. 8, the frequency of system configuration change may be divided into three, high, medium, and low, and it may be determined which weighting coefficient is assigned based on the frequency of high, medium, and low. . Similarly, also in step S306 and step S309, the length of the high-voltage line and the low-voltage line is divided into the length of the lead-in line being long, medium, and short, and the margin for the upper limit voltage of the normal system voltage before interconnection. You may make it divide into three like large, medium, and small.

FIG. 10 is an example of combinations of weighting coefficients in the present embodiment. FIG. 11 shows another example of combinations of weighting coefficients in the present embodiment. As shown in FIG. 10 and FIG. 11, each weighting coefficient is based on the frequency of system configuration change, the length of the high-voltage line and the low-voltage line is the length of the lead-in line, and the margin for the upper limit voltage of the normal system voltage before interconnection. to determine the K ₁ ~K _4. Further, these combination patterns may be written and stored in the storage unit 6 in advance.
As an example, when the frequency of system configuration change is high, the length of the high-voltage line and low-voltage line is the length of the lead-in line = long, and the margin for the upper limit voltage of the normal system voltage before interconnection is large = optimal power calculation The unit 5 selects K ₁ = 0.5625, K ₂ = 0.1875, K ₃ = 0.1875, and K ₄ = 0.0625 for each weighting coefficient. Using each of the weighting coefficients K _{1 to} K ₄ selected in this way, the optimum power calculation unit 5 calculates the reactive power Q _G by Equation (5) and outputs it to the connection point.

In the conventional technique, when the voltage is high due to system side factors, the reactive power output by the distributed power supply may stick to the limiter limit value, and the voltage rise caused by the distributed power supply PW1 cannot be compensated effectively. There was also. According to this embodiment, in addition to the weighting factor of the prior art, even using a weighting coefficient K ₄ against reactive power Q _JiderutaV optimum output power calculating unit 5 is based on the interconnection point voltage fluctuation described in the first embodiment controlling the voltage compensation to generate a reactive power Q _G Te. That is, as described in the first embodiment, the maximum value ΔV _m of the voltage fluctuation due to the output of the dispersion device PW1 is measured or estimated in advance, the power factor is determined by the voltage fluctuation ΔV at an arbitrary time, and the voltage fluctuation ΔV is measured in advance. Alternatively, the reactive power Q _GΔV is generated so that the power factor decreases as the estimated maximum value is approached, and the amount of change in the interconnection point voltage is controlled, so that the voltage increase caused by the distributed power source PW1 can be effectively compensated.

  In this embodiment, the example in which the optimum output power calculation unit 5 determines the weighting coefficient based on the information stored in the storage unit 6 has been described. However, the processing in FIG. 9 is processed in the distributed power source. Instead, for example, only the weighting factors K1 to K4 finally determined by the installer or the system operator of the distributed power source as an off-line operation are written and stored in the storage unit 6 and controlled based on the stored information. It may be. In this case, the determination of the weighting coefficient may be performed only when the distributed power source is installed and during periodic review work such as once a year.

As described above, in addition to the weighting factors K _{1 to} K ₃ of the conventional method, the weighting factor K ₄ is set to the reactive power Q _GΔV calculated using the reactive power control method according to the first embodiment and is invalidated. since to perform the voltage compensation by calculating a power Q _G, even when the voltage is high the mains factors, compensation for variations in the interconnection point voltage reactive power output is never stick to the limiter limits by distributed power It becomes possible to do.

In the present embodiment, the case where the voltmeter 1 is built in the distributed power source PW1 has been described. However, the voltmeter 1 is not necessarily provided in the distributed power source PW1, and may be provided separately. That is, the detection power calculation in distributed power PW1 voltmeter 1 linking point voltage V detected, interconnection node voltage V _{0 m,} interconnection node voltage V _m, interconnection node voltage V ₀ provided separately The data may be output to the unit 3 (not shown).

Further, in the first embodiment, the connection point voltage V _m and the connection point voltage V _0m are measured by setting the power generation amount to 0 at the rated power (or maximum power), and the connection point voltage V ₀ is generated at an arbitrary time. The example of setting 0 to zero has been explained, but it may not be strictly the rated power (or maximum power), and the interconnection point voltage V _m is measured when it is within a predetermined range (for example ± 1%), and further power generation The amount 0 may not be strictly 0, and the interconnection point voltage V _0m may be measured when the amount is within a predetermined range (for example, + 1%). Similarly, the interconnection point voltage V ₀ may be measured when the power generation amount is within a predetermined range (for example, + 1%).

  In the present embodiment, the distributed power source PW1 has been described, but the present invention is not limited to these. The distributed power source according to the present invention is a relatively small-capacity power source in general that does not have an influence on the power system so that the system voltage can be determined independently, among the power generation facilities linked to the power system. These include solar power generation, wind power generation, small hydropower generation, fuel cells, combined heat and power generation facilities or waste incineration power generation.

Moreover, although this embodiment demonstrated the case where this invention was applied to the power distribution equipment which is a part of electric power system, this invention is not limited to this. The present invention is also applicable to a system that operates independently from the power system or a system that operates in conjunction with the power system. One example of a system operating independently from such a power system or a system operating in conjunction with the power system is a microgrid.
At present, there is no unified definition for microgrids, but microgrids are composed of a combination of distributed power sources and power storage systems, and supply power that matches the power demand by adjusting the amount of power generated by distributed power sources. Usually, it is operated independently from the power system, but may be operated in conjunction with the power system as necessary. The present invention can be applied as one component of such a microgrid.
One definition of the microgrid includes a variety of distributed power sources including a distributed power source using natural energy, but the present invention is not limited to this. It is a distributed power source that uses a gas turbine or the like and does not use natural energy, and there may be only one type of distributed power source.

It should be noted that a program for realizing the function of each unit in FIG. 1 of the embodiment is recorded on a computer-readable recording medium, and the program recorded on this recording medium is read into a computer system and executed, thereby executing each unit. Processing may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” is a portable medium such as a flexible disk, a magneto-optical disk, a ROM (Read Only Memory), a CD-ROM, or a USB (Universal Serial Bus) I / F (interface). A storage device such as a USB memory or a hard disk built in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, it also includes those that hold a program for a certain period of time, such as a volatile memory inside a computer system serving as a server or client in that case. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

S ... Distribution substation C1 ... High-voltage distribution lines T1, T2 ... Distribution transformer (post transformer)
C2 ... Low voltage distribution line PW1 ... Distributed power supply L ... Load 1 ... Voltmeter 2 ... Ammeter 3 ... Detected power calculation unit 4 ... Output power judgment unit 5 ... Optimal output power calculation unit 6 ... storage unit 7 ... output current setting unit 8 ... output current control unit 9 ... inverter 10 ... DC power supply 11 ... interconnection reactor

Claims (13)

A power generation unit that generates active power and reactive power and outputs it to the interconnection point;
A voltage detector for detecting the interconnection point voltage;
An output power instruction generating unit that generates an instruction to reduce the power output to the interconnection point to a first predetermined power generation amount;
The first voltage fluctuation value, which is the difference between the second interconnection point voltage at the first predetermined power generation amount with respect to the first interconnection point voltage at the rated power or maximum power, and the third interconnection point voltage at an arbitrary time A control unit that controls the power generation unit based on a second voltage fluctuation value that is a difference between the fourth interconnection point voltages at the first predetermined power generation amount and the reactive power corresponding to a second predetermined power factor. When,
A distributed power source characterized by comprising: The controller is
Obtaining a third interconnection point voltage at the arbitrary time, reducing the generated power at the arbitrary time to the first predetermined power generation amount, obtaining a fourth interconnection point voltage at the first predetermined power generation amount; The distributed power supply according to claim 1, wherein the second voltage fluctuation value is calculated by calculating a difference of the fourth interconnection point voltage with respect to the third interconnection point voltage. The controller is
A first interconnection point voltage at the time of the rated power or maximum power is acquired, and the second interconnection point voltage at the time of the first predetermined power generation amount is decreased from the rated power or maximum power to the first predetermined power generation amount. The distributed voltage source according to claim 2, wherein the first voltage fluctuation value is calculated by obtaining a difference between the second interconnection point voltage and the first interconnection point voltage. The controller is
The first voltage fluctuation value is estimated using the predetermined rated power or maximum power, the generated power at the arbitrary time, the third interconnection point voltage, and the fourth interconnection point voltage. The distributed power source according to claim 2. The frequency of calculating the second voltage fluctuation value is higher than the frequency of acquiring the fourth interconnection point voltage, and the frequency of acquiring the fourth interconnection point voltage is higher than the frequency of calculating the first voltage fluctuation value. The distributed power supply according to claim 3 or 4, characterized in that there are many. The controller is
When the second voltage fluctuation value is greater than 0 and the second voltage fluctuation value is less than the first voltage fluctuation value, the active power, the second predetermined power factor, and the first interconnection point voltage are Generating reactive power based on the second interconnection point voltage, the third interconnection point voltage, and the fourth interconnection point voltage to control the power generation unit;
When the second voltage fluctuation value is larger than the first voltage fluctuation value, the reactive power based on the active power and the second predetermined power factor is generated to control the power generation unit,
6. The distributed power supply according to claim 1, wherein, when the second voltage fluctuation value is less than 0, the reactive power generation unit generates zero reactive power to control the power generation unit. 6. . The controller is
If the second voltage variation value is large and the second voltage change value from 0 in the range of less than the first voltage variation value, the active power the P _G and tanφ based on the second predetermined power factor first Relational expression P _G × (tan φ) × (V−V) composed of a connection point voltage V _m , the second connection point voltage V _0m , the third connection point voltage V and the fourth connection point voltage V _{0 0} ) / (V _m −V _0m ) to generate reactive power and control the power generation unit,
When the second voltage fluctuation value is greater than the first voltage fluctuation value, reactive power is generated based on the active power P _G and a relational expression P _G × (tan φ) composed of tan φ based on the second predetermined power factor. And controlling the power generation unit,
6. The distributed power supply according to claim 1, wherein, when the second voltage fluctuation value is less than 0, the reactive power generation unit generates zero reactive power to control the power generation unit. 6. . The controller is
Control is performed until the absolute value of the second voltage fluctuation value falls within a third predetermined range, or control is performed until the reactive power reaches a value based on the second predetermined power factor of the power generation output. The distributed power source according to claim 1, wherein the power source is a distributed power source. The distributed power source according to claim 8, wherein the third predetermined range is based on accuracy of voltage measurement of the voltage detection unit or accuracy of current measurement.
The controller is
A system impedance of the power system is estimated, and a predetermined binary value RBX relating to the active power, a ratio of a resistance component and a reactance component of the system impedance estimation value, and a ratio of the resistance component and the reactance component of the system impedance estimation value _L , RBX _H (where RBX _L is smaller than RBX _H ) and a first reactive power Q _GRX based on the second predetermined power factor;
A second reactive power Q _GZ based on the active power, a system impedance estimated value of the power system, a predetermined binary value Z _L , Z _H (where Z _L is smaller than Z _H ) and a power factor; ,
A predetermined invalid value V _L , V _H (where V _L is smaller than V _H ) related to the connection point voltage, the active power, and the connection point voltage, and a third invalidity based on the second predetermined power factor. Power Q _GV ,
The interconnection point voltage, the active power, the rated power or maximum power, the first interconnection point voltage, the second interconnection point voltage, the third interconnection point voltage, the fourth interconnection point voltage, and A fourth reactive power Q _GΔV based on the second predetermined power factor;
A weighting factor K ₁ for the first reactive power Q _GRX ;
A weighting factor K ₂ for the second reactive power Q _GZ ;
A weighting factor _{K 3} for the third reactive power _{Q GV,}
A weighting coefficient K ₄ for the fourth reactive power Q _GΔV ;
The distributed power supply according to any one of claims 1 to 5, wherein the reactive power is controlled using the reactive power. In a distributed power source connected to at least one of a plurality of distributed power sources, a high voltage line, and a low voltage line,
The controller is
Is it at least the cumulative length of the overhead transmission line of the high-voltage line or low-voltage line, the frequency of changing the system configuration including the distributed power supply, or the margin for the upper limit voltage value of the normal system voltage before interconnection? 11. The distributed type according to claim 10 , wherein the weights of the weighting coefficient K ₁ , the weighting coefficient K ₂ , the weighting coefficient K ₃ , and the weighting coefficient K ₄ are determined based on any one of the following. Power supply.
The controller is
The system impedance Z of the power system is estimated, the active power P _G , the ratio R / X of the resistance component R and reactance component X of the system impedance estimation value Z, and a predetermined binary value RBX _L relating to the ratio R / X , RBX _H (where RBX _L is smaller than RBX _H ) and the first reactive power Q _GRX based on the relational expression (6) consisting of the second predetermined power factor cosφ,
From the active power P _G , the system impedance estimation value Z of the power system, predetermined binary values Z _L and Z _H (where Z _L is smaller than Z _H ) and the second predetermined power factor cos φ A second reactive power Q _GZ based on the relational expression (7)
The connection point voltage V, the active power P _G , predetermined binary values V _L and V _H related to the connection point voltage (where V _L is smaller than V _H ), and the second predetermined power factor cos φ. A third reactive power Q _GV based on the relational expression (8);
The connection point voltage V, the active power P _G , the rated power or maximum power P _m , the first connection point voltage V _m , the second connection point voltage V _0m , the third connection point voltage V A fourth reactive power Q _GΔV based on the relational expression (9) consisting of the fourth interconnection point voltage V ₀ and the second predetermined power factor cos φ,
A weighting factor K ₁ for the first reactive power Q _GRX ;
A weighting factor K ₂ for the second reactive power Q _GZ ;
A weighting factor _{K 3} for the third reactive power _{Q GV,}
A weighting coefficient K ₄ for the fourth reactive power Q _GΔV ;
The distributed power supply according to any one of claims 1 to 5, wherein the reactive power is controlled using the reactive power.

In the distributed power supply control method of the distributed power supply,
A power generation step in which the power generation unit generates active power and reactive power and outputs the generated power to the interconnection point;
A voltage detection step in which the voltage detection unit detects a connection point voltage;
An output power instruction generating unit that generates an instruction to reduce the power output to the interconnection point to a first predetermined power generation amount; and
The control unit includes a first voltage fluctuation value that is a difference between the second interconnection point voltage at the first predetermined power generation amount with respect to the first interconnection point voltage at the rated power or the maximum power, and a third linkage at an arbitrary time. Based on the second voltage fluctuation value, which is the difference between the fourth predetermined point voltage at the first predetermined power generation amount with respect to the system point voltage, and the reactive power corresponding to the second predetermined power factor, A control process to control;
A distributed power supply control method comprising:

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