JP2010183701A - Voltage monitor control method by voltage monitor control system of distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage control method for efficiently performing voltage control by giving high incentive to an owner of a distributed power supply with high control sensitivity since a cooperation cost of voltage control is evaluated in accordance with a voltage improvement degree in monitor control of a distributed system to which many distributed power supplies are connected. <P>SOLUTION: A method evaluates an effect given to the system of the distributed power supply. An amount is collected as system link charge. A voltage is efficiently improved by power factor control by optimizing calculation. Incentive is given in accordance with a contribution degree to voltage improvement. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a voltage monitoring control method by a voltage monitoring control system of a distribution system in which a plurality of distributed power sources are interconnected.

  In a power distribution system in which a large number of distributed power sources are connected, there is a concern that a voltage increase may occur due to an increase in reverse power flow. In the conventional power distribution system, the voltage distribution has been optimized using voltage control equipment such as an automatic voltage regulator (SVR) and a reactive power compensator (SVC: Static Var Compensator).

  However, since the occurrence of overvoltage due to the introduction of the distributed power supply greatly depends on the introduction location and the introduction amount of the distributed power supply, it is difficult to determine the introduction location of the voltage adjustment equipment in advance.

  On the other hand, a distributed power source that is connected using an inverter can supply and absorb reactive power by controlling the power factor, and thus can contribute to voltage control. Therefore, when the distributed power source is arranged so as to be spread across the surface, the surface voltage control can be performed without additional capital investment by utilizing the power factor control function of the distributed power source.

JP 2004-274812 A (paragraph [0054], FIG. 1)

  In the literature 1, as cooperation for maintaining the voltage quality by reactive power control, compensation is paid for the number of times of control or the integrated value of the controlled reactive power, and for the amount of active power output limited by reactive power control. Is also disclosed to pay consideration.

  According to the method of Literature 1, there is a possibility that a distributed power source with low control sensitivity outputs a large amount of reactive power. Therefore, the amount of reactive power generated in the entire system also increases, and there is a possibility that the problem of increasing the power loss of the system may occur.

  Furthermore, since a distributed power source with low control sensitivity generates a large amount of reactive power, an unfairness arises in that a distributed power source with a low contribution to voltage improvement gets more consideration.

  In addition, since the system operator bears all the cooperation costs for maintaining the voltage quality, there is a concern that the costs required for voltage adjustment will be recorded as electricity charges and will be recovered from all consumers. The

  The present invention has been made to solve the above-described problems, and performs efficient control and improves profits for both distributed power supply owners and consumers who do not have distributed power supplies. It is an object of the present invention to provide a voltage monitoring control method using a voltage monitoring control system for a distribution system capable of maximizing the active power output from the power distribution system.

  A voltage monitoring control method by a voltage monitoring control system for a distribution system according to the present invention is a voltage monitoring control method by a voltage monitoring control system for a distribution system in which distributed power sources capable of controlling reactive power output are interconnected. Collects data on the operating status and distribution system status of the type power supply to monitor and control the distribution system voltage.When the system voltage deviates from the appropriate range, the output of the system power is controlled by the reactive power output control of the distributed power source. In the voltage monitoring control method by the voltage monitoring control system of the distribution system that prevents deviation from the proper range, when determining the control amount of the reactive power output of the distributed power source by simulation, the active power output of each distributed power source is almost the same amount The output of each distributed power supply when any one of the system voltages reaches the upper limit of the appropriate range is used as a reference output. In this state, the reactive power output of each distributed power supply is individually controlled, and the active power of the distributed power supply when any one of the system voltages reaches the upper limit of the appropriate range is defined as P′max, and the distributed power supply An amount obtained by multiplying the difference (Pmax−P′max) from the maximum active power output Pmax by the power selling unit price in the time period is calculated as the grid connection fee of the distributed power source, and each distributed type is calculated by optimization calculation. When the reactive power control amount of each distributed power source is determined so that the system voltage is within an appropriate range with the total reactive power of the power source being in the minimum range, the active power output of each distributed power source is set as Popt. An amount obtained by multiplying the difference (Pmax−Popt) from the maximum active power output Pmax by the unit price of power sold in the time period is calculated as an opportunity loss cost of the distributed power source, and further, from the total grid connection fee The remaining amount minus the total loss cost is calculated as a voltage control reward according to the contribution to the voltage improvement of each distributed power source, the reactive power control amount of each distributed power source is determined, and It calculates the grid connection fee, opportunity loss compensation fee, and voltage control incentives for the type power supply.

  Therefore, it is possible to perform efficient control and minimize the active power output from each distributed power source by minimizing reactive power controlled for voltage improvement by optimization calculation in the entire system. Provides a voltage monitoring and control method using the voltage monitoring and control system of the distribution system. Furthermore, the voltage monitoring and control system calculates the grid connection fee according to the degree of influence on the grid from the owner of the distributed power station. By calculating the charge as the opportunity loss compensation cost according to the control amount, and calculating it as a voltage control reward according to the contribution to voltage improvement, it becomes easier to obtain cooperation for voltage monitoring and control. It is possible to maximize the active power output from.

  In the voltage monitoring control method by the voltage monitoring control system of the distribution system according to the present invention, when the control amount of the reactive power output of the distributed power source is determined by simulation, any one part of the system voltage reaches the upper limit of the appropriate range. The active power output of each distributed power supply is increased by approximately the same amount in order, and then the maximum active power P′max that the voltage in the system can be output within the appropriate range while each distributed power supply individually controls the reactive power. Since the charge according to the difference (Pmax−P′max) from the maximum value Pmax of the active power output is calculated as the grid connection charge, each distributed power owner has an influence degree on the grid. Depending on the system, the grid connection fee will be borne, the fairness among the owners of distributed power sources will be maintained, the introduction of distributed power sources will be promoted, and cooperation for voltage monitoring and control will be easily obtained, and eventually There is an effect that makes it possible to maximize the active power output from the distributed power supply.

  In addition to paying opportunity loss compensation costs to distributed power supply owners whose active power has been reduced by reactive power control, we evaluated the contribution to voltage improvement of each distributed power supply and paid for it, By giving incentives to highly distributed power sources, it is easier to obtain cooperation for improving the voltage of each distributed power source.

  In addition, by collecting the grid connection fee from the owner of the grid-connected distributed power source, and by paying the cost required for improving the system voltage in the collected grid connection fee, This has the effect of eliminating the burden on ordinary consumers who do not own it.

It is a figure which shows Embodiment 1 of this invention, and is a flowchart which performs voltage monitoring control of a distribution system. It is a figure which shows Embodiment 1 of this invention, and is a figure which shows an example of a system configuration | structure. It is a figure which shows Embodiment 1 of this invention, and is explanatory drawing which shows an example of a grid connection charge. It is a figure which shows Embodiment 1 of this invention, and is explanatory drawing which shows an example of opportunity loss compensation expense. It is a figure which shows Embodiment 1 of this invention, and is explanatory drawing which shows an example of a voltage control reward. It is a figure which shows Embodiment 1 of this invention, and is explanatory drawing which shows an example of the collection | recovery cost of a distributed power supply.

Embodiment 1 FIG.
FIG. 1 is a flowchart showing an example of an execution flow of the voltage monitoring control method of the present invention. The execution flow will be described below in the order of flow.

  Measurement data read processing by the measurement data read processing function (step ST1), measurement data collected at regular intervals and stored in the system is read, and voltage distribution calculation by the voltage distribution calculation function (step ST2) A simulation is performed to determine the voltage at each node.

  In the voltage departure determination process (step ST3) by the voltage departure determination processing function, it is determined whether or not the voltage is within the proper range. If the voltage is out of the proper range, the following processing is performed. Ends the process.

  In the grid interconnection impact assessment (step ST4) by the grid interconnection impact assessment function, the impact on the grid when each distributed power source is operating at the maximum output with a power factor of 1.0 is evaluated. Calculate interconnection charges.

  The optimal control amount calculation by the optimal control amount calculation function (step ST5) is a reactive power output of the distributed power source so that the voltage of each node of the system is within an appropriate range in a state where the reactive power of the system is minimum by the optimization calculation. To decide.

  In the active power reduction amount calculation by the active power reduction amount calculation function (step ST6), the output reduction amount of the active power accompanying the reactive power output of the distributed power source is calculated, and the opportunity loss compensation cost is calculated.

  In the voltage improvement contribution evaluation by the voltage improvement contribution evaluation function (step ST7), the contribution to the voltage improvement of each distributed power source is calculated, and then the voltage control reward is calculated.

  The voltage control output (step ST8) in the voltage control output function outputs the reactive power control amount obtained by the optimum control amount calculation (step ST5) to the target distributed power source.

  FIG. 2 is a system configuration diagram for executing the voltage monitoring control method for the distribution system according to the present invention. Hereinafter, the configuration and functions of the system will be described with reference to FIG.

  In FIG. 2, the on / off state of the switch 22 installed in the high-voltage distribution line 21 and the voltage and current data of the distribution system are transmitted to the voltage monitoring control device 26 via the slave station 23, the communication line 24, and the communication master station 25. Is done.

  The operating state of the distributed power supply 30 is transmitted to the voltage monitoring control device 26 via the slave station 23, the communication line 24, and the communication master station 25.

  A control command for the distributed power supply 30 is transmitted through the route of the voltage monitoring control device 26, the communication master station 25, the communication line 24, and the slave station 23.

  Next, the operation of the system of FIG. 2 will be described.

  The voltage monitoring control device 26 collects the operation state of the distributed power source 30, the on / off state of the switch 22, and the voltage and current data of the distribution system at regular intervals via the slave station 23, the communication line 24, and the communication master station 25. Then, voltage monitoring control of the distribution system is performed.

  The voltage monitoring control device 26 performs processing according to the flow chart of FIG. 1 based on the collected data, and when it is determined that the voltage of the distribution system is out of the proper range, reactive power control for improving the voltage. The amount is calculated and a control command is output to the distributed power source to be controlled.

  When performing control for voltage improvement, simultaneously with calculation of the control amount, the grid connection fee, opportunity loss compensation cost, and voltage control reward are calculated as costs required for control, and the calculation results are accumulated.

  First, the degree of influence of the distributed power source i on the grid is evaluated by the following procedure, and the grid interconnection charge is calculated.

(1) Increase the output of each distributed power supply by a small amount, and obtain the output (reference output) of the distributed power supply when any of the nodes N1 to N6 deviates from the appropriate voltage. (See Fig. 3 (B))
(2) From the state of (1) above, find the effective power (P'max, i) that can be output within the appropriate voltage range when the distributed power source i individually controls the power factor. (Refer to FIG. 3C)
(3) Since the distributed power source i has an adverse effect on the system when the active power exceeding P′max, i is output, the difference between the maximum output Pmax, i of the distributed power source and the P′max, i is Active power that affects
(4) The amount obtained by multiplying the difference Ploss1, i between the maximum output Pmax, i of the distributed power source and the above P'max, i by the surplus power purchase price Cp in that time zone is calculated as the grid interconnection charge SCFi.
See formula below.
Ploss1, i = Pmax, i−P'max, I
SCFi = Ploss1, i × Cp

Next, in the optimum control amount calculation 4, the reactive power output of each distributed power source is determined.
Power factor control is performed to maintain the system voltage within an appropriate range by centralized control of the distributed power supply.
The active power output Popt and the reactive power output Qopt of each distributed power source are determined by optimization calculation using the reactive power output of the distributed power source as a minimum.
The optimization calculation is performed by the following algorithm.
[Objective function]
Mini ΣQgi ²
[Restrictions]
(Tidal current equation)
Pgi−Pli−ViΣVk {Gik cos (θi−θk) + Bik sin (θi−θk)} = 0
Qgi−Qli−ViΣVk {Gik sin (θi−θk) + Bik cos (θi−θk)} = 0
I = 1, 2, 3,... N
(Upper and lower limits of distributed power supply reactive power output)
Qgi_min ≤ Qgi ≤ Qgi_max
(Node voltage upper and lower limit constraints)
Vmin ≤ Vi ≤ Vmax
(Power factor constraint of distributed power supply)
√ (P ² + Q ² ) = S
here,
m: number of distributed power supplies n: total number of nodes Pgi, Qgi: active / reactive power output of distributed power supply i Pli, Qli: active / reactive power output of load i
Vi, θi: voltage of bus i, phase Gik, Bik: conductance between buses i and k, susceptance Qgi_min, Qgi_max: upper and lower limits of reactive power output of distributed power source i
Vmin, Vmax: Upper and lower limits of node voltage

Next, in the active power decrease calculation 6, Ploss2, i is the amount by which the active power of the distributed power source i is reduced by the reactive power control from the active power output Popt, i of the distributed power source i obtained by the optimal control amount calculation. And Ploss2, i multiplied by the surplus power purchase price for that time period is used as the opportunity loss compensation fee OLCI.
See formula below.
Ploss2, i = Pmax, i-Popt, i
OLCI = Ploss2, i × Cp
here,
Ploss2, i: Effective power decrease of distributed power source i by control execution Pmax, i: Maximum value of active power output of distributed power source i Popt, i: Active power output of distributed power source i by optimization calculation OLCI: Distributed FIG. 4 shows an example in which the system voltage is improved within an appropriate range by the power factor control of the distributed power sources G5 and G6, and the distributed power sources G5 and G6 obtain the mechanical loss compensation cost. ing.

Next, after calculating the node voltage improvement degree and the contribution degree of each distributed power source to the voltage improvement of each node in the voltage improvement contribution evaluation 7, the voltage control reward is calculated.
First, the voltage improvement degree VCRi of the node i is calculated as follows.
When each distributed power source is operating at a power factor of 1.0 and maximum output, the voltage at node i is Vi, the upper limit of the appropriate voltage range is Vu, and VCRi is as follows.
VCRi = (Vi−Vu) / Σ (Vj−Vu)
j = 1 to N
In the example of FIG. 5, the improvement level VCR6 of the node 6 is as follows.
VCR6 = (V6-Vu) / {(V2-Vu) + (V3-Vu) + (V4-Vu)
+ (V5−Vu) + (V6−Vu)}

Next, the degree of contribution VCi, j for the voltage improvement of the node j of the distributed power source i is calculated as follows.
VCi, j = Vi, j / ΣVi, k
here,
k = 1 to N
Vi, j: Change amount of node j due to active power and reactive power control of distributed power source I In the example of FIG.
VC6,6 = V6,6 / (V6,6 + V5,6)
Further, the contribution level VC5,6 of the power supply 5 to the node 6 is as follows.
VC5,6 = V5,6 / (V6,6 + V5,6)

Based on the above calculation, the voltage control reward VCRj of the distributed power source j is set as follows.
Voltage reward for power supply j = (total grid connection charge-total opportunity loss charge) x {Σ of node i
Voltage improvement × contribution of power supply j to node i}
= (Σ (SCFi−OLCI)) × ΣVCRI × VCj, i
I = 1 to N
FIG. 6 shows an example of costs recovered by the distributed power sources G1 to G6.
In the radial power distribution system, the control sensitivity becomes higher at the end, so that many control commands are likely to be output to the distributed power supply connected to the vicinity of the end of the system.
For this reason, distributed power supply owners with high control sensitivity have more opportunities to obtain incentives for control cooperation, and they can induce participation in control cooperation and can perform control efficiently.

  As described above, Embodiment 1 of the present invention is a voltage monitoring control method by a voltage monitoring control system for a distribution system in which distributed power sources capable of controlling reactive power output are interconnected. Status and distribution system status data is collected online to monitor and control the distribution system voltage, and when the system voltage deviates from the appropriate range, the output of the reactive power of the distributed power source controls the deviation of the system voltage from the proper range. In the voltage monitoring control method by the voltage monitoring control system of the distribution system to prevent, when determining the control amount of the reactive power output of the distributed power source by simulation, the active power output of each distributed power source is increased by a minute amount in order. The output of each distributed power source when any one of the system voltages reaches the upper limit of the appropriate range is used as a reference output, and the reactive power output of each distributed power source is set in the state of the reference output. Separately, the active power of the distributed power source when any one of the system voltages reaches the upper limit of the appropriate range is defined as P′max, and the difference (Pmax−) from the maximum active power output Pmax of the distributed power source P'max) is multiplied by the unit price of electricity sold in the time period as the grid connection fee for the distributed power source, and the system voltage with the total reactive power of each distributed power source minimized by optimization calculation The effective power output of each distributed power source when the reactive power control amount of each distributed power source is determined to be within an appropriate range is set as Popt, and the difference (Pmax−Popt) from the maximum active power output Pmax of the distributed power source ) Multiplied by the unit price of electricity sold during the time period as the opportunity loss cost of the distributed power source, and the remaining amount obtained by subtracting the total opportunity loss cost from the total grid connection fee It is calculated as a voltage control reward according to the contribution to the voltage improvement of the distributed power supply, and the reactive power control amount of each distributed power supply is determined, and the grid connection fee and opportunity loss compensation fee for the distributed power supply A voltage monitoring control method by a voltage monitoring control system of a distribution system, characterized in that a voltage control reward is calculated.

  Further, in the first embodiment of the present invention, in the monitoring control of a distribution system in which a large number of distributed power sources are connected, the cooperation cost of voltage control is evaluated according to the degree of voltage improvement. By providing a high incentive to the owner of a highly distributed power supply, we provide a voltage control method that enables efficient voltage control, and evaluates the impact on the distributed power supply system. In addition to collecting as an interconnection fee, the power factor is controlled efficiently by power factor control by optimization calculation, and incentives are given according to the contribution to voltage improvement.

  As described above, in the voltage monitoring control method by the voltage monitoring control system according to the first embodiment of the present invention, the opportunity compensation cost is given according to the control amount, and the voltage control reward is given according to the contribution to the voltage improvement. It is something to give. Therefore, it is easy to obtain control cooperation of a distributed power source owner with high control sensitivity, and there is an effect that control can be performed efficiently.

  In addition, when determining the control amount of the reactive power output of the distributed power source through simulation, the active power output of each distributed power source is increased by the same amount in order until one of the system voltages reaches the upper limit of the appropriate range. Then, the maximum active power P′max that can be output within the appropriate range of the voltage in the system is obtained while each distributed power source individually controls the reactive power, and the difference (Pmax−) from the maximum value Pmax of the active power output is obtained. P′max) is calculated as a grid connection charge, and each distributed power owner bears the grid connection charge according to the degree of influence on the grid. It is possible to maintain fairness among owners of distributed power sources, promote the introduction of distributed power sources, facilitate cooperation in voltage monitoring control, and maximize the effective power output from each distributed power source. To say There is a result.

  In addition to paying opportunity loss compensation costs to distributed power supply owners whose active power has been reduced by reactive power control, we evaluated the contribution to voltage improvement of each distributed power supply and paid for it, By giving incentives to highly distributed power sources, it is easier to obtain cooperation for improving the voltage of each distributed power source.

  In addition, by collecting the grid connection fee from the owner of the grid-connected distributed power source, and by paying the cost required for improving the system voltage in the collected grid connection fee, This has the effect of eliminating the burden on ordinary consumers who do not own it.

  In addition, it can be expected to promote the introduction of distributed power sources and contribute to global warming countermeasures.

1 Measurement data reading process,
2 Voltage distribution calculation processing,
3 Voltage deviation judgment processing,
4 Grid connection impact assessment process,
5 Optimal control amount calculation processing,
6 Active power output reduction calculation processing,
7 Voltage improvement degree evaluation process,
8 Voltage control output processing,
21 21 High voltage distribution line,
22 22 Switch,
23 23 Slave station for communication,
24 24 communication lines,
25 25 Communication master station,
26 26 voltage monitoring and control device,
30 30 Distributed power supply.

Claims (1)

A voltage monitoring control method by a voltage monitoring control system of a distribution system connected to a distributed power source capable of controlling the output of reactive power, collecting data on the operating state and distribution system status of the distributed power source online Voltage monitoring and control method by voltage monitoring control system of distribution system that monitors and controls voltage and prevents deviation of system voltage from proper range by output control of reactive power of distributed power source when system voltage deviates from proper range In
When determining the control amount of reactive power output of the distributed power source by simulation, the active power output of each distributed power source is increased in order by almost the same amount, and one of the system voltages reaches the upper limit of the appropriate range. When the output of each distributed power source is used as the reference output, and the reactive power output of each distributed power source is individually controlled in the state of the reference output, and one of the system voltages reaches the upper limit of the appropriate range An amount of power obtained by multiplying a difference (Pmax−P′max) from the maximum active power output Pmax of the distributed power source by the power selling unit price in the time period is defined as P′max. When calculating the power system interconnection fee and determining the reactive power control amount of each distributed power source so that the system voltage is within the appropriate range with the total reactive power sum of each distributed power source being at the minimum by optimization calculation of An opportunity loss cost of the distributed power source is calculated by multiplying the difference (Pmax-Popt) from the maximum active power output Pmax of the distributed power source by the power selling unit price in the time zone with the active power output of the distributed power source as Popt. In addition, the remaining amount obtained by subtracting the total opportunity loss cost from the total grid connection fee is calculated as a voltage control reward according to the contribution to the voltage improvement of each distributed power source. The reactive power control amount is determined, and the grid monitoring fee, opportunity loss compensation fee, and voltage control reward for the distributed power source are calculated. Control method.

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