WO2022270030A1

WO2022270030A1 - Power system operation plan support system, power system operation plan support method, and program

Info

Publication number: WO2022270030A1
Application number: PCT/JP2022/010169
Authority: WO
Inventors: 準板井; 裕小海; 英佑黒田; 弘一原
Original assignee: 株式会社日立製作所
Priority date: 2021-06-24
Filing date: 2022-03-09
Publication date: 2022-12-29
Also published as: JP2023003787A

Abstract

This power system operation plan support system comprises: a vibration suppression index evaluation unit that outputs an evaluation result by a power system vibration suppression index created on the basis of system stability determination criteria data; a vibration suppression index improvement plan creation unit that uses the evaluation result and the data of a facility to be changed as inputs to create, while satisfying a vibration suppression index criteria, an initial improvement plan for maximizing the total amount of the outputs of renewable energy power supplies designated in a power system to be calculated; and a system voltage improvement plan creation unit that outputs, on the basis of the initial improvement plan, an improvement plan for maximizing the total amount of the outputs of the renewable energy power supplies while satisfying the voltage criteria of the system stability determination criteria data.

Description

POWER SYSTEM OPERATION PLANNING SUPPORT SYSTEM, POWER SYSTEM OPERATION PLANNING SUPPORT METHOD AND PROGRAM

The present invention relates to a power system operation plan support system, a power system operation plan support method, and a program.

In power systems, the introduction of renewable energy power sources such as wind power and solar power is progressing with the aim of reducing carbon dioxide emissions. Along with this, the number of operating synchronous machines used for thermal power generation and hydroelectric power generation tends to decrease. Here, the synchronous machine described in this specification refers to a synchronous generator, a synchronous motor, or a synchronous phase modifier, and hereinafter collectively referred to as a synchronous machine. Synchronous machines have the ability to keep the voltage of the power system constant, but renewable energy sources often do not have this ability. Therefore, it is feared that the capacity to maintain the voltage of the electric power system will decline due to the large-scale introduction of renewable energy power sources.

A decline in the voltage maintenance capability of the power system may affect the stability of the operating state of renewable energy sources and the stability of the power system. For example, many wind power generators connected to a power system via an inverter output active power and reactive power in amounts based on the magnitude of the voltage at the connection point of the wind power generator. Therefore, in a situation where the voltage maintenance capacity of the power system is low and the voltage at the connection point of the wind power generation is likely to change due to changes in the number of operating circuits of the transmission lines of the power system and changes in the output of the wind power generation, the voltage at the connection point of the wind power generation It is known that a change in voltage causes a change in the wind power output, which again causes a change in the voltage at the connection point of the wind power generator.

As a result, it has been confirmed that the output and voltage of wind power generation continue to experience unstable oscillations that do not fall within a certain value. Wind turbines are often connected together in locations with good wind conditions, so if the output of one wind turbine causes unstable vibrations, the output of other wind turbines adjacent to it will also be adversely affected. Stable vibration spreads, and eventually the entire power system becomes unstable.

Techniques described in Patent Document 1, Patent Document 2, and Patent Document 3 are known as techniques for solving this problem.
In Patent Document 1, by measuring one or more of the voltage, active power, and reactive power at a connection point between a renewable energy farm composed of a plurality of renewable energy power generation systems and the power system, the power system Techniques for estimating strength are described.

The technique described in Patent Document 1 determines the sensitivity of voltage to one or more of active power and reactive power, and determines the strength of the power system as a function of the sensitivity. It then dynamically determines one or more of the active power command value and the reactive power command value for the renewable energy farm based on the strength of the power system.

In addition, Patent Document 2 discloses a configuration in which the power generation output of the generator is controlled based on at least two types of measurement data received from the connection point between the generator and the power system, and based on at least two of the measurement data There is a description of technology for creating a model of a power system using Here, the power system model is characterized by an equivalent power system voltage and an equivalent power system impedance. In addition, in Patent Document 2, at least two of the measurement data are used to calculate a value indicating the strength of the power system based on the power system model, and based on the value indicating the strength, the power generation output is controlled. technique is described.

In addition, Patent Document 3 describes a technique for determining a power system state such as a vulnerable state and controlling a power plant such as a wind power plant or a photovoltaic power plant in a manner appropriate to the power system state. . Here, the technology described in Patent Document 3 measures the output parameters of generators such as wind power generation and solar power generation, determines the relationship between the measured output parameters, and determines the relationship between the measured output parameters. In order to prevent possible vibration phenomena in the power plant, the power plant is controlled according to the relationship.

U.S. Patent Application Publication No. 2020/0328611 U.S. Patent Application Publication No. 2019/0131795 U.S. Patent Application Publication No. 2015/0361954

In the techniques described in Patent Literature 1, Patent Literature 2, and Patent Literature 3, the output of the renewable energy power source is controlled in order to prevent the generation of unstable vibration of the renewable energy power source.
As described in these documents, if only curbing the output of renewable energy power is taken, the output of renewable energy power cannot be utilized to the maximum.
Therefore, the degree of contribution to the reduction of carbon dioxide emissions, which is the purpose of introducing renewable energy sources, will be weakened. Therefore, in order to reduce the amount of carbon dioxide emissions, it is necessary to prevent the occurrence of unstable vibrations in renewable energy power sources by minimizing output suppression of renewable energy power sources.

An example of a method to prevent curtailment of renewable energy power sources is to reduce the impedance value of the power system as seen from the wind power generation connection point by increasing the number of transmission lines and transformer banks in operation. This approach may improve the ability to maintain voltage at the wind turbine connection and prevent the occurrence of unstable vibrations.

However, if measures other than curbing the output of renewable energy power sources are taken, there is a concern that the voltage of the power system will deviate from the appropriate range for operation because the state of the operating equipment of the system will be changed. In addition, since the number of transmission lines and the number of transformer banks in operation can only be changed in stages, it was mathematically difficult to calculate appropriate countermeasures for optimization problems.

As described above, there are various problems with the conventional technology, and a power system that can make the most of the output of the renewable energy power supply while simultaneously suppressing the unstable vibration of the renewable energy power supply and maintaining the voltage of the power system. It has been desired to provide an operation plan support system, power system operation plan support method and program.

In order to solve the above problems, for example, the configurations described in the claims are adopted.
The present application includes a plurality of means for solving the above problems. The power system to be calculated while satisfying the vibration suppression index standards of the system stability judgment standard data by inputting the vibration suppression index evaluation unit that outputs the evaluation results by the vibration suppression index and the evaluation results and the equipment data subject to operation status change. and a vibration suppression index improvement plan creation unit that creates an initial improvement plan that maximizes the total amount of output of the renewable energy power source specified in .
Furthermore, the power system operation plan support system of the present invention outputs an improvement plan that maximizes the total amount of renewable energy power output while satisfying the voltage standard of the system stability criterion data based on the initial improvement plan. and an output unit that outputs or displays information of the vibration suppression index evaluation unit, the vibration suppression index improvement plan creation unit, and the system voltage improvement plan creation unit.

According to the present invention, by reducing the output suppression amount of the renewable energy power supply necessary to prevent the occurrence of unstable vibration of the renewable energy power supply due to the decrease in the voltage maintenance capability of the power system, the amount of carbon dioxide emissions can be further reduced.
In addition, according to the present invention, a method is sought that can maximize the output of the renewable energy power supply while preventing both the occurrence of unstable vibrations in the renewable energy power supply and deviation of the voltage of the power system from the proper range. can reduce the time required for
Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS It is a functional block diagram which shows the structural example of the electric power system operation plan assistance system of the 1st Embodiment of this invention. It is a figure which shows an example of the data structure of the system|strain structure data D11 of the 1st Embodiment of this invention. It is a figure which shows an example of the data structure of the system operation plan data D12 of the 1st Embodiment of this invention. It is a figure which shows an example of the data structure of the system model data D13 of the 1st Embodiment of this invention. 4 is a diagram showing an example of the data structure of calculation target data D14 according to the first embodiment of this invention; FIG. It is a figure which shows an example of the data structure of the system stability criterion data D15 of the 1st Embodiment of this invention. It is a figure which shows an example of the data structure of the operation state change object equipment data D16 of the 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the structural example of the hardware of the power system operation plan assistance system of the 1st Embodiment of this invention. 4 is a flow chart showing an example of overall processing of the power system operation plan support system according to the first embodiment of the present invention; 4 is a flow chart showing an example of processing of the vibration suppression index improvement plan creation unit 24 according to the first embodiment of the present invention; 4 is a flow chart showing an example of processing by a system voltage improvement plan creation unit 27 according to the first embodiment of the present invention; FIG. 4 is a diagram showing an example of a screen displaying a state of a future electric power system targeted for improvement of an operation plan and an improvement proposal for the operation plan according to the first embodiment of the present invention; It is a figure which shows an example of the screen which displays the effect by the improvement of the operation plan of the 1st Embodiment of this invention. It is a figure which shows an example of the unstable vibration suppression effect of the renewable energy power supply of the 1st Embodiment of this invention. It is a figure which shows an example of the output amount increase effect of the renewable energy power supply of the 1st Embodiment of this invention. FIG. 3 is a functional block diagram showing a configuration example of a power system operation plan support system according to a second embodiment of the present invention; FIG. 5 is a block diagram showing a hardware configuration example of a power system operation plan support system according to a second embodiment of the present invention; It is a flow chart which shows the example of the whole processing of the electric power system operation plan support system of the 2nd embodiment example of the present invention. FIG. 11 is a functional block diagram showing a configuration example of a power system operation plan support system according to a third embodiment of the present invention; FIG. 11 is a block diagram showing a hardware configuration example of a power system operation plan support system according to a third embodiment of the present invention; It is a flow chart which shows the example of the whole processing of the electric power system operation plan support system of the example of the 3rd embodiment of the present invention.

<First Embodiment>
A first embodiment of the present invention will be described below with reference to FIGS. 1 to 15. FIG.
[Configuration of Power System Operation Planning Support System]
FIG. 1 shows the configuration viewed from the function of a power system operation plan support system 1 of the first embodiment.
The power system operation plan support system 1 includes input data D1 held in advance by the operator of the power system, a calculation unit 2 that creates an improvement plan for the power system operation plan based on the input data D1, and the input data D1 and calculation. It is composed of a display section 3 for displaying the contents of the section 2 .

The calculation unit 2 includes an analysis cross section creation unit 21, a vibration suppression index calculation unit 22, a vibration suppression index evaluation unit 23, a vibration suppression index improvement plan creation unit 24, a system voltage calculation unit 25, a system voltage evaluation unit 26, and a system voltage improvement unit. It is composed of a draft creation unit 27 and performs processing in this order.
The input data D1 consists of system configuration data D11, system operation plan data D12, system model data D13, calculation target data D14, system stability criterion data D15, and operation status change target facility data D16.
The details of the functions of the units 21 to 27 constituting the calculation unit 2 will be specifically explained in the explanation of the flow charts described later with reference to FIGS. 9 to 11. FIG.

The display unit 3 displays the analysis cross section, the vibration suppression index improvement plan, and the system voltage improvement plan created by the analysis cross section creation unit 21, the vibration suppression index improvement plan creation unit 24, and the system voltage improvement plan creation unit 27. FIG. Further, the display unit 3 may display calculation results and evaluation results of the vibration suppression index calculation unit 22, the vibration suppression index evaluation unit 23, the system voltage calculation unit 25, and the system voltage evaluation unit 26. For example, the operator selects which item to display.
Here, the power system operation plan support system 1 is provided with the display unit 3 to display an example, but instead of the display unit 3, an output unit is provided to display each information via a network or the like. It may be output to the outside and displayed on the receiving terminal.

[System configuration data]
FIG. 2 shows an example of the data structure of the system configuration data D11 in the input data D1.
The system configuration data D11 stores information about transmission lines and synchronous machines that configure the power system. The transmission line information includes detailed information on the characteristics of each transmission line, such as the number of lines, connection source busbar, connection destination busbar, resistance R, reactance X, and the like.
The information on the synchronous machines includes detailed information on characteristics such as link bus, number of parallel machines, rated capacity, rated output, reactance X, and the like. The synchronous machine here is at least one of a synchronous generator, a synchronous motor, and a synchronous phase modifier, as already explained.
Although not shown in FIG. 2, the system configuration data D11 includes information on the power transmission lines and synchronous machines that make up the power system, as well as information on loads, renewable energy power sources, transformers, phase modifying equipment, and the like. are stored regardless of their operational state.

[System operation plan data]
FIG. 3 shows an example of the data structure of the system operation plan data D12 in the input data D1.
The system operation plan data D12 includes future plans for switching on and off circuit breakers used in transmission lines and transformers, future plans for active power output of synchronous machines, prediction data for active power consumption of loads, and the like. stored in time intervals. The data held by the system operation plan data D12 includes not only the data shown in FIG. It also includes the active power output plan and reactive power output plan of the power system, and the operation plan of each bus voltage in the power system.

[System model data]
FIG. 4 shows an example of the data structure of the system model data D13 in the input data D1.
The system model data D13 stores details such as the model type and various constants, which are related information, regarding models of the synchronous machine (SG), the renewable energy power source (RES), and the load. Information on these models of synchronous machines, renewable energy sources, and loads is necessary for numerical analysis of electric power systems using computers and calculators.
Note that the system model data D13 includes not only information on synchronous machines, renewable energy power sources, and loads, but also information on models such as transmission lines, transformers, and phase modifying equipment.

[Calculation target data]
FIG. 5 shows an example of the data structure of calculation target data D14 in input data D1.
The calculation target data D14 stores information on the number of the bus for which the vibration suppression index is calculated by the vibration suppression index calculator 22 and the number of the bus for which the system voltage is calculated by the system voltage calculator 25. .

[System stability criterion data]
FIG. 6 shows an example of the data structure of the system stability criterion data D15 in the input data D1.
The system stability judgment reference data D15 includes a reference value (SCR lower limit) used for evaluation of the vibration suppression index in the vibration suppression index calculation unit 22 and a reference value (voltage upper limit) used for evaluation of the system voltage in the system voltage evaluation unit 26. value, voltage lower limit) is stored.

[Equipment data subject to operation status change]
FIG. 7 shows an example of the data structure of the operation status change target facility data D16 in the input data D1.
The operation state change target equipment data D16 stores information about transmission lines, transformers, synchronous machines, etc., which are considered as improvement methods in the vibration suppression index improvement plan creation unit 24 and the system voltage improvement plan creation unit 27. .

For example, as information on the number of transmission line operation circuits, the number of changeable operation circuits is stored for each change target transmission line. In addition, as information on the number of transformer banks, the number of changeable banks is stored for each transformer to be changed. Also, as information on the number of parallel synchronous machines, the changeable number of parallel machines is stored for each synchronous machine to be changed. Furthermore, as information on the transformer tap, a changeable tap ratio range is stored for each transformer to be changed.

Note that the operation status change target equipment data D16 does not include information about system equipment that cannot be used as an improvement method due to some restrictions, such as transmission lines that cannot change the number of operating circuits from the existing operation plan due to work or maintenance. Marked as excluded and not stored.
In addition to the data shown in FIG. 7, the operation status change target equipment data D16 includes, for example, information related to power capacitors and shunt reactors subject to change in the number of inputs, and information related to synchronous machines subject to change in reactive power. and information about renewable energy sources whose active power output is subject to change.

[Hardware Configuration of Power System Operation Planning Support System]
FIG. 8 shows an example of the hardware configuration of the power system operation plan support system 1 of this embodiment.
The power system operation planning support system 1 includes program data D2a, a display unit 3, an input unit 4, a CPU (Central Processing Unit) 5, a memory 6, various input data D11 to D16, and a bus line connecting these 7. The program data D2a and various input data D11 to D16 are stored, for example, in a non-volatile storage unit (not shown).

The program data D2a is composed of an analysis cross section creation program, a vibration suppression index calculation program, a vibration suppression index evaluation program, a vibration suppression index improvement plan creation program, a system voltage calculation program, a system voltage evaluation program, and a system voltage improvement plan creation program. .

The display unit 3 is composed of, for example, one or more of a display device, a printer device, a projector device, an audio output device, and the like.
The display unit 3 displays the input data D1 shown in FIG. An example of the display screen will be described later.
The input unit 4 is composed of, for example, one or more of a keyboard, a switch, a mouse, a touch panel, a voice input device, and the like.

The CPU 5 reads a program necessary for the processing of the calculation unit 2 from among various programs constituting the program data D2a and executes calculation. The CPU 5 may be composed of one or more semiconductor chips, or may be composed of a computer or calculator.
The memory 6 is composed of a storage device such as a RAM (Random Access Memory), and stores programs read from the program data D2a, calculation result data created by the calculation unit 2, image data, and the like.

[Overall Processing Flow of Power System Operation Planning Support System]
FIG. 9 is a flow chart showing the overall processing flow of the power system operation plan support system 1 in this embodiment.
First, the analysis section creation unit 21 uses the system configuration data D11, the system operation plan data D12, and the system model data D13 to create an analysis section of the power system in the future, for example, after 30 minutes or 1 hour (step S21). ).

Next, the vibration suppression index calculator 22 uses the analysis cross section created in step S21 to calculate the vibration suppression index of the bus specified in the calculation target data D14 (step S22). That is, the vibration suppression index calculator 22 receives the analysis cross section of the electric power system and the calculation target data, and outputs the calculation result of the vibration suppression index. The vibration suppression index here indicates at least one of the unstable vibration of the output and voltage of the renewable energy power source, or the voltage maintenance capability of the power system.
As vibration suppression indices, already known SCR (Short Circuit Ratio), WSCR (Weighted Short Circuit ratio), CSCR (Composite Short Circuit Ratio), SCRIF (Short Circuit Ratio with Interaction Factors), SDSCR (Site-Dependent Short Circuit Ratio), etc., is used.

For any of these indices, the larger the value, the less likely it is that unstable vibrations will occur in renewable energy power sources, so they are used as a guideline for determining whether or not unstable vibrations in renewable energy power sources have occurred.

Here, as a calculation example of the vibration suppression index, the SCR calculation formula is shown in [Equation 1]. In the formula [Equation 1], SCRi is the SCR at the connection bus of the i-th renewable energy power supply, Vi is the voltage of the connection bus of the i-th renewable energy power supply, and Zi is the connection bus of the i-th renewable energy power supply. is the impedance of the entire power system viewed, Pi is the active power output of the i-th renewable energy source, and R is the set of all renewable energy source numbers.

　Vi and Pi required for calculating the formula [Equation 1] can be obtained, for example, by executing a power flow calculation on the analysis cross section created in step S21. Also, Zi is obtained by referring to the analysis cross section created in step S21.

Next, the vibration suppression index evaluation unit 23 performs vibration suppression index evaluation processing for evaluating whether or not the vibration suppression index calculated in step S22 satisfies the reference value using the system stability judgment reference data D14. (Step S23). If it is determined in step S23 that the reference value is satisfied (YES in step S23), the process proceeds to step S3, and the results obtained in steps S21 to S23 are displayed on the display unit 3. FIG.

Further, when it is evaluated that the reference value is not satisfied in step S23 (NO in step S23), the vibration suppression index improvement plan creation unit 24 changes the operating state so that the vibration suppression index satisfies the reference value. Vibration suppression index improvement plan creation processing for creating an improvement plan for the operation plan is performed using the target facility data D16 (step S24). A specific example of the improvement plan creation procedure in step S24 will be described later.
Next, the system voltage calculation unit 25 calculates the voltage of the bus designated by the calculation target data D14 using the analysis cross section created in step S21 and the operation plan improvement plan created in step S24 (step S25 ). It should be noted that the system voltage in step S24 is obtained by power flow calculation, for example.

Next, the system voltage evaluation unit 26 uses the system stability criterion data D14 to evaluate whether or not the voltage calculated in step S25 is within an appropriate range (step S26).
If it is evaluated as being within the appropriate range in step S26 (YES in step S26), the process proceeds to step S3, and the results obtained in steps S21 to S26 are displayed on the display section 3. FIG.

On the other hand, if it is evaluated that the voltage is not within the proper range in step S26, that is, if the voltage standard of the system stability criterion data D14 is not satisfied (NO in step S26), the system voltage improvement plan creation unit 27 In order to keep the voltage outside the proper range within the proper range, the operational state change target facility data D16 is used to create an improvement proposal for the operational plan (step S27). A specific example of the improvement plan creation procedure in step S27 will be described later.
After creating an improvement plan for the operation plan, the process moves to step S3, and the results obtained in steps S21 to S27 are displayed on the display unit 3. FIG.

The series of processes shown in FIG. 9 are periodically executed in a time span that allows the process to be completed, such as 10 minutes or 30 minutes.

[Procedure for creating vibration suppression index improvement plan]
Next, with reference to the flowchart of FIG. 10, an example of a procedure for creating a vibration suppression index improvement plan, which is an initial improvement plan in step S24 of the flowchart of FIG. 9, will be described. The improvement plan here is at least the number of operating circuits of transmission lines that make up the power system, the number of operating transformers, the number of operating synchronous machines (number of parallel machines), and the active power output of renewable energy power sources. It includes one or more operational plan changes as improvements.

First, the vibration suppression index improvement plan creation unit 24 solves an optimization problem for creating a vibration suppression index improvement plan using the calculation target data D14, the system stability judgment reference data D15, and the operation state change target equipment data D16. An objective function, constraints, and decision variables are set (step S241).

Here, the objective function and the constraint conditions are, for example, as shown in [Equation 2]. In [Equation 2], SCR _ref,i is the reference value of SCR at the connection bus of the i-th renewable energy power supply.

In addition, the decision variables for the formula [Formula 2] are the number of operating circuits of each transmission line in the power system, the number of banks of each transformer, the number of parallel synchronous machines, the tap ratio of each transformer, and each renewable energy power source. is the active power output Pi of . However, in order not to deteriorate the vibration suppression index, the number of operating lines of transmission lines, the number of transformer banks, and the number of parallel synchronous machines cannot be reduced. Conversely, it is assumed that the transformer tap ratio and the active power output of the renewable energy power source cannot be increased.

Next, the vibration suppression index improvement proposal creation unit 24 creates a power flow cross section of the electric power system for calculating the vibration suppression index using the analysis cross section created in step S21 (step S242).

Next, the vibration suppression index improvement plan creation unit 24 selects one type of power system equipment parameters to be changed in order to improve the vibration suppression index (step S243). Here, the parameters to be changed are the number of operating lines of the transmission line of the power system, the number of transformer banks, the number of parallel synchronous machines, the transformer tap ratio, the regeneration Examples include the active power output of renewable energy sources.

The order of selection of the parameters can be arbitrarily set by the operator of the power system via the input unit 4. However, since maximization of the active power output of the renewable energy power supply is set as the objective function here, it is desirable that the order of selection of the active power output of the renewable energy power supply be later. In step S243, the parameters are selected in the set selection order, and if there is no changeable parameter among the selected parameters, the parameters in the next order are selected.

Next, the vibration suppression index improvement plan creation unit 24 determines the total amount of increase in the vibration suppression index in the connection bus of each renewable energy power source when each parameter belonging to the parameter class selected in step S243 is changed by a specified amount. A value O _sum,j is obtained by, for example, power flow calculation (step S244). Here, each parameter is said to be changed by a specified amount, but the amount by which the parameter is changed can be arbitrarily set by the power system operator through the input unit 4 .

The total amount of increment O _sum,j is expressed, for example, by the formula [Equation 3]. In Equation 3, SCR _{aft, ij} represents the SCR at the connection bus of the i-th renewable energy power supply after changing the j-th power system equipment parameter by a specified amount. Also, SCR _{bef, ij} represents the SCR in the connection bus of the i-th renewable energy power source before changing the j-th power system equipment parameter by a specified amount, and P represents a set of all parameter numbers.

Next, the vibration suppression index improvement plan creation unit 24 changes the parameter with the largest increase in the vibration suppression index _{Osum, j} calculated in step S244 by the specified amount. A vibration suppression index on the generatrix is calculated (step S245). As the vibration suppression index to be obtained here, the value calculated when obtaining the total increase amount _Osum,j of the vibration suppression index in step S244 may be used as it is.

Next, the vibration suppression index improvement plan creation unit 24 evaluates whether or not each vibration suppression index obtained in step S245 is equal to or greater than a reference value (step S246). If it is evaluated in step S246 that it is equal to or greater than the reference value (YES in step S246), the vibration suppression index improvement plan creation unit 24 determines all the parameter changes made in step S245 as improvement plans, and starts the process. finish.

On the other hand, if it is evaluated that the value is not equal to or greater than the reference value in step S246 (NO in step S246), the vibration suppression index improvement plan creation unit 24 applies the last parameter change in step S245 to the vibration suppression index. It is reflected in the tidal flow cross section to be used (step S247). After that, the vibration suppression index improvement plan creation unit 24 returns to the process in step S243.

[Procedure for creating system voltage improvement plan]
Next, with reference to the flowchart of FIG. 11, an example of the system voltage improvement plan creation procedure in step S27 of the flowchart of FIG. 9 will be described. As described below, the system voltage improvement plan creation unit 27 performs a system voltage improvement plan creation process for creating an improvement plan for the bus voltage based on the calculation result of the system voltage calculation unit 25 and the voltage reference. It outputs improvement proposals.
First, the system voltage improvement plan creation unit 27 uses the calculation target data D14, the system stability judgment reference data D15, and the operation state change target facility data D16 to create the system voltage improvement plan. , constraints, and decision variables are set (step S260).

The objective function and constraint conditions are, for example, as shown in [Equation 4]. V _j in the formula (4) is the magnitude of the voltage of the j-th bus, V _{LL, j} is the lower limit of the proper range of the voltage of the j-th bus, and V _{UL, j} is the proper voltage of the j-th bus. Represents the upper value of the range. Note that N indicates a set of all busbar numbers.

Also, the decision variables for the [Formula 4] formula are the number of power capacitors and shunt reactors to be turned on, the reactive power output of the synchronous machine, and the reactive power output of the renewable energy power supply. Power system equipment that adjusts reactive power in the power system has little effect on voltage maintenance capability of the power system due to changes in reactive power. Therefore, the voltage of the electric power system can be improved without deteriorating the vibration suppression index improved in step S24.

In addition to the information on the power system equipment described above, variables of the power system equipment that are considered to have a small adverse effect on the vibration suppression index may be included as decision variables for the [Equation 4] formula. In other words, it is possible to create an improvement plan that maximizes the total output of renewable energy power sources while satisfying both the vibration suppression index standard and the voltage standard by using an improvement method that is considered to have little adverse effect on the vibration suppression index. good.
For example, the number of operating lines of transmission lines, the number of transformer banks, the number of parallel synchronous machines, etc. may be included as decision variables on the condition that they are increased, the transformer tap ratio, the active power output of renewable energy power sources, etc. may be included as a decision variable provided that it is reduced.

Next, the system voltage improvement plan creation unit 27 creates a power flow cross section of the power system for calculating the system voltage, using the analysis cross section created in step S21 and the vibration suppression index improvement plan created in step S24. (step S261).
Next, the system voltage improvement proposal creation unit 27 selects one type of parameters of the power system equipment to be changed in order to improve the system voltage (step S262). Note that the parameters to be changed in step S262 are the same as the decision variables set in step S261, such as the number of power capacitors and shunt reactors to be turned on, the reactive power output of the synchronous machine, the transformer tap ratio, the reproducible Active power output and reactive power output of the energy source.

The order in which the parameters are selected can be arbitrarily set by the power system operator via the input unit 4. However, since maximization of the active power output of the renewable energy power supply is set as the objective function here, it is desirable that the order of selection of the active power output of the renewable energy power supply be later. A step S262 selects the parameters in the set selection order, and if there is no changeable parameter among the selected parameters, selects the parameters in the next order.

Next, the system voltage improvement plan creation unit 27 obtains the amount of change in each calculation target voltage when each parameter belonging to the parameter class selected in step S262 is changed by a unit amount, that is, the sensitivity, for example, by power flow calculation. (Step S263). The unit amount to be changed means the minimum amount that each parameter can be changed. , one unit is the unit quantity.

Next, the system voltage improvement plan creation unit 27 calculates the voltage deviation suppression amount V _sum,j for each parameter using the values of each system voltage before and after the change of each parameter calculated in step S263, and calculates the voltage deviation The parameter with the maximum suppression amount V _sum,j is selected (step S264).

The voltage excursion suppression amount V _sum,j is expressed, for example, by the formula [Equation 5]. ΔV _ij in the formula [Equation 5] is an index showing how much the magnitude of the i-th bus voltage approaches the appropriate range by changing the unit amount of the j-th power system equipment parameter. ] expression. Here, V _{bef, ij} indicates the magnitude of the i-th bus voltage before the j-th power system equipment parameter is changed by the unit amount, and V _{aft, ij} is the j-th power system equipment parameter changed by the unit amount. It shows the magnitude of the later i-th bus voltage.

Next, the system voltage improvement plan creation unit 27 calculates the total voltage to be calculated and the voltage deviation suppression amount each time while changing the parameter selected in step S264 by unit amount within a changeable range (step S265). . For example, when the parameter selected in step S264 is the number of shunt reactors to be turned on, the voltage to be calculated is obtained by multiplying the sensitivity obtained in step S263 by a unit amount such as 2 units, 3 units, or 4 units. It is obtained by adding to the voltage before changing the parameter. Also, the voltage excursion suppression amount is obtained by multiplying the value of the formula [Equation 5] obtained in step S264 by a value for every unit amount.

Next, the system voltage improvement plan creation unit 27 determines whether or not there is a case in which all the voltages to be calculated fall within the proper range in step S265 (step S266). If there is a corresponding case in step S266 (YES in step S266), the parameter change performed in step S265 is reflected in the improvement plan, and the process ends.

On the other hand, if there is no corresponding case in step S266 (NO in step S266), the system voltage improvement proposal creation unit 27 selects the parameter change that maximizes the voltage deviation suppression amount among the parameter changes in step S265. is reflected in the improvement plan (step S267).

Next, the system voltage improvement proposal creation unit 27 determines whether or not there are still system facilities that can be changed for system voltage improvement (step S268). If it is determined in step S268 that changeable system equipment remains (YES in step S268), the parameter change made in step S267 is reflected in the power flow cross section used for system voltage calculation (step S269). , the process returns to step S262.
On the other hand, if it is determined in step S268 that there is no system equipment that can be changed (NO in step S268), the calculation of the optimization problem is terminated, and the process ends.

[Display example]
Here, an example of the display on the display unit 3 will be described with reference to FIGS. 12 and 13. FIG.
FIG. 12 is an example of a screen in which a display 31 of the state of the electric power system at a specific time in the future targeted for improvement of the operation plan and a display 32 of an improvement plan for the operation plan are arranged side by side.
In this example, the state of the power system is displayed 31 in the form of a system diagram display 31a and a tabular form 31b as the power flow state of the power system in the future and the operation status of various system facilities.
Further, the display 32 of the operation plan improvement plan output by the calculation unit 2 is also performed in tabular form 32a to 31d.
Specifically, as the display 32 of the operation plan improvement plan, a table 32a of the number of operating circuits of the transmission line, a table 32b of the number of operating synchronous machines, a table 32c of the number of shunt reactors (ShR) input, and a Figure 32d shows a table 32d of Soyo facilities (SC) inputs.

FIG. 13 is an example of a screen of

displays

33 and 34 showing the effect of improving the operation plan. In this example, a display 33 before the operation plan improvement and a display 34 after the improvement by the operation plan improvement plan are arranged side by side.
Here, as the display 33 before the operation plan improvement, a list 33a of renewable energy output, SCR, and SCR reference value, and a list 33b of voltage, upper limit value, and lower limit value of each bus line are shown. Further, as a display 34 after operation plan improvement, a list 34a of renewable energy output, SCR, and SCR reference value, and a list 34b of voltage, upper limit value, and lower limit value of each bus are shown.

The power system operator can refer to the screen shown in FIG. 13 and consider whether or not to reflect the created operation plan improvement plan in the actual operation plan.
Information displayed by the display unit 3 is not limited to the examples shown in FIGS. 12 and 13 . For example, information of various input data D11 to D16, intermediate data generated during the processing of the vibration suppression index improvement plan creation unit 24 and the system voltage improvement plan creation unit 27, etc. can be displayed as necessary.

[Effects of First Embodiment]
14 and 15, the effects of the power system operation plan support system of this embodiment will be described.
FIG. 14 shows a time-series waveform 101 of the active power output of the renewable energy power source before applying the power system operation plan support system of this embodiment, and the power system operation plan support system of this embodiment. Fig. 10 compares time-series waveforms 102 of active power output of renewable energy power sources after

In the time-series waveform 101 of the active power output of the renewable energy power supply before application, the output of the renewable energy power supply is unstable and oscillating, and the output suppression is required.
On the other hand, in the time-series waveform 102 of the active power output of the renewable energy power supply after application, the output of the renewable energy power supply is stable, and output suppression is unnecessary. In this manner, by applying the power system operation plan support system of the present embodiment, it is possible to prevent unstable oscillation of the active power output of the renewable energy power supply.

FIG. 15 compares the output state 201 of the renewable energy power source before application of the power system operation plan support system of the present embodiment and the output state 202 of the renewable energy power source after application.
Before applying the power system operation plan support system of the present embodiment, the output of a part of the renewable energy power source was suppressed in order to prevent unstable vibration of the renewable energy power source. In the example of FIG. 15, for example, the renewable energy output total value was 200 MW.

On the other hand, after applying the power system operation planning support system of the present embodiment, it is possible to prevent unstable vibration without suppressing the output of the renewable energy power source. The value can be 300 MW. In other words, by applying the power system operation plan support system of this embodiment, the total output of renewable energy power sources can be increased, and the amount of carbon dioxide emissions can be further reduced.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS. 16 to 18. FIG. 16 to 18, the same reference numerals are given to the same components or the same steps as those in FIGS. 1 to 15 described in the first embodiment, and redundant description will be omitted.

[Configuration of Power System Operation Planning Support System]
FIG. 16 shows the configuration viewed from the function of the power system operation plan support system 1 of the second embodiment of the present invention.
In the power system operation plan support system 1 of the present embodiment, in addition to evaluating the vibration suppression index, instantaneous value analysis processing of the renewable energy power source is performed in order to determine whether or not unstable vibration of the renewable energy power source has occurred. It is an addition.

Then, as a result of the instantaneous value analysis, only when unstable vibration of the renewable energy power source is confirmed, proceed to the improvement plan creation process for the operation plan. As a result, the amount of processing increases by the amount of instantaneous value analysis, but if the vibration suppression index does not meet the standard value even though the unstable vibration of the renewable energy power source does not occur, an improvement plan is created. processing can be omitted.

As shown in FIG. 16, in the power system operation plan support system 1, an unstable vibration determination unit 28 is added to the calculation unit 2, which is the power system operation plan of the first embodiment example shown in FIG. It differs from the support system 1.
The information of the evaluation result of the vibration suppression index evaluation unit 23 is supplied to the unstable vibration determination unit 28, and the unstable vibration determination unit 28 performs instantaneous value analysis processing of the renewable energy power source, Determine the presence or absence of
Information on the presence or absence of unstable vibration determined by the unstable vibration determination unit 28 is supplied to the vibration suppression index improvement proposal creation unit 24 together with information on the evaluation result of the vibration suppression index evaluation unit 23 .

In addition, for the instantaneous value analysis processing in the unstable vibration determination unit 28, a reference for determining whether or not unstable vibration has occurred is separately required as data held by the system stability determination reference data D15.
In addition, the analysis section for instantaneous value analysis is also required for the instantaneous value analysis processing in the unstable vibration determination unit 28 . Therefore, the system model data D13 additionally holds power system model data for instantaneous value analysis, and based on this, the analysis section creating unit 21 creates an analysis section for instantaneous value analysis.
Other configurations of the power system operation plan support system 1 shown in FIG. 16 are the same as those of the power system operation plan support system 1 shown in FIG. 1, so description thereof will be omitted.

[Hardware Configuration of Power System Operation Planning Support System]
FIG. 17 shows an example of the hardware configuration of the power system operation planning support system 1 according to the second embodiment of the present invention.
The power system operation plan support system 1 shown in FIG. 17 differs from the program data D2a of the power system operation plan support system 1 shown in FIG. 8 in that a renewable energy unstable vibration determination program is added as program data D2b. do. The renewable energy unstable vibration determination program is read when the calculation unit 2 executes the unstable vibration determination unit 28 .

[Overall Processing Flow of Power System Operation Planning Support System]
FIG. 18 is a flow chart showing the overall process flow of the power system operation plan support system 1 in the second embodiment of the present invention. Compared with the flow of processing in the first embodiment shown in FIG. 9, the flow of processing shown in FIG. is added by step S28 for confirming by instantaneous value analysis and step S29 for determining the presence or absence of unstable vibration of the renewable energy power source.

That is, when it is evaluated that the reference value is not satisfied in step S23 (NO in step S23), the unstable vibration determination unit 28 confirms the operating state of the renewable energy power supply by instantaneous value analysis (step S28). , the presence or absence of unstable vibration of the renewable energy power source is determined (step S29). In step S29, if there is no unstable vibration of the renewable energy power supply (NO in step S29), the process proceeds to step S3, and display processing is performed.
On the other hand, in step S29, if there is unstable vibration of the renewable energy power source (YES in step S29), the process proceeds to step S24 to create a vibration suppression index improvement plan.
Other processes in the flowchart of FIG. 18 are executed in the same flow as in the flowchart of FIG.

As described above, according to the power system operation plan support system 1 in the second embodiment, even if the unstable vibration of the renewable energy power source does not occur, the vibration suppression index does not satisfy the reference value. In this case, the improvement proposal creation process can be omitted.
In the second embodiment, instantaneous value analysis is used to determine whether or not an improvement plan needs to be created, but the usage is not limited to this. For example, the vibration suppression index improvement plan creation unit 24 may use instantaneous value analysis to determine whether or not the created improvement plan prevents unstable vibration.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIGS. 19-21. In FIGS. 19 to 21 as well, the same components or steps as those in FIGS. 1 to 18 described in the first and second embodiments are denoted by the same reference numerals, and redundant description is omitted.
In the power system operation plan support system 1 of this embodiment, the processing performed by the power system operation plan support system 1 is reduced by screening.

That is, in the third embodiment, the improvement method is screened when creating an improvement plan for either or both of the vibration suppression index and the system voltage. As a screening method, for example, improvement methods are narrowed down only to system equipment whose electrical distance from the bus line does not satisfy the reference value for the vibration suppression index, and whose electrical distance is equal to or less than a certain distance. The electrical distance here is obtained using, for example, the magnitude of impedance between two points. This can reduce the amount of calculation required to create an improvement plan.

[Configuration of Power System Operation Planning Support System]
FIG. 19 shows the configuration viewed from the function of the power system operation plan support system 1 in the third embodiment of the present invention.
The power system operation plan support system 1 shown in FIG. 19 differs from the power system operation plan support system 1 shown in FIG. 1 in that screening reference data D17 is added to the input data D1.
The screening reference data D<b>17 becomes input data for the vibration suppression index improvement plan creation unit 24 and the system voltage improvement plan creation unit 27 .

[Hardware Configuration of Power System Operation Planning Support System]
FIG. 20 shows an example of the hardware configuration of the power system operation plan support system 1 according to the third embodiment of the present invention.
The power system operation plan support system 1 shown in FIG. 20 is provided with the screening reference data D17, and the change target facility screening program is added as the program data D2c. program data D2a. The facility screening program to be changed is read when the calculation unit 2 executes either or both of the vibration suppression index improvement plan creation unit 24 and the system voltage improvement plan creation unit 27 .

[Overall Processing Flow of Power System Operation Planning Support System]
FIG. 21 is a flow chart showing the overall process flow of the power system operation plan support system 1 according to the third embodiment of the present invention. Compared with the flow of processing in the first embodiment shown in FIG. 9, the flow of processing shown in FIG. A screening step S30 is added. Furthermore, a step S31 of screening a system voltage improvement method is added before the step S27 of creating a system voltage improvement plan. Only one of step S30 and step S31 may be used instead of both.

That is, when the vibration suppression index improvement plan creation unit 24 determines that the reference value is not satisfied in step S23 (NO in step S23), the vibration suppression index improvement plan creation unit 24 screens the vibration suppression index improvement means using the screening reference data D17. (Step S30).
Further, when the system voltage is not within the appropriate range in step S26 (NO in step S26), the system voltage improvement plan creation unit 27 screens the system voltage improvement means using the screening reference data D17 (step S31). .
Other processes are executed in the same flow as the flow chart shown in FIG.

By performing the process of screening the improvement method of the vibration suppression index and the process of screening the method of improving the system voltage in this way, the process performed by the power system operation planning support system 1 can be reduced.

<Modification>
It should be noted that the embodiments described so far have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.

For example, in each of the described embodiments, the power system operation plan support system 1 creates an improvement plan on the premise that the power system, synchronous machine, and renewable energy power supply equipment are all existing equipment. I made it
On the other hand, you may make it create the improvement plan when one of facilities is reinforced. For example, when increasing the number of renewable energy power sources connected to an existing power system, the power system operation plan support system 1 may examine whether or not vibration can be suppressed, and create an improvement plan.
In this way, by creating an improvement plan for increasing power equipment, the power system operation plan support system 1 can examine whether or not the equipment reinforcement is appropriate.

In addition, in the configuration diagrams shown in FIGS. 1 and 8, etc., only those control lines and information lines that are considered necessary for explanation are shown, and not all control lines and information lines are necessarily shown on the product. No. In fact, it may be considered that almost all configurations are interconnected.
In addition, in each of the embodiments described above, FIG. 8 and the like show the case where the power system operation plan support system is configured by a computer. On the other hand, some or all of the functions performed by the power system operation planning support system may be realized by hardware such as FPGA (Field Programmable Gate Array) and ASIC (Application Specific Integrated Circuit).
Also, it is an example to configure the power system operation plan support system 1 as one device, for example, a device holding the input data D1 shown in FIG. may be configured and connected via a network, etc.

When the power system operation planning support system 1 is configured by an information processing device such as a computer, the program may be prepared in non-volatile storage or memory in the computer, or may be stored in an external memory, IC card, SD card, It may be placed on a recording medium such as an optical disk and transferred.

DESCRIPTION OF SYMBOLS 1... Power system operation plan support system, 2... Calculation part, 3... Display part, 4... Input part, 5... CPU, 6... Memory, 7... Bus line, 21... Analysis section preparation part, 22... Vibration suppression index calculation Part 23 Vibration suppression index evaluation unit 24 Vibration suppression index improvement plan creation unit 25 System voltage calculation unit 26 System voltage evaluation unit 27 System voltage improvement plan creation unit 28 Unstable vibration determination unit , D1: input data, D2a, D2b, D2c... program data, D11... system configuration data, D12... system operation plan data, D13... system model data, D14... data to be calculated, D15... system stability criteria data, D16 ... operation status change target equipment data, D17 ... screening reference data

Claims

A vibration suppression index evaluation unit that outputs an evaluation result based on the vibration suppression index of the power system created based on the system stability criterion data;
Using the evaluation result and the data of equipment subject to operation status change as input, the total amount of output of the renewable energy power source specified in the power system to be calculated is maximized while satisfying the vibration suppression index standard of the system stability judgment standard data. A vibration suppression index improvement plan creation department that creates an initial improvement plan to
a system voltage improvement plan creation unit that outputs an improvement plan that maximizes the total amount of output of the renewable energy power source while satisfying the voltage standard of the system stability criterion data based on the initial improvement plan;
An electric power system operation plan support system, comprising: an output unit that outputs or displays information of the vibration suppression index evaluation unit, the vibration suppression index improvement plan creation unit, and the system voltage improvement plan creation unit.
The initial improvement plan includes the number of operating circuits of the transmission lines that make up the power system, the number of operating transformers, the number of operating synchronous generators, the number of operating synchronous motors, the number of operating synchronous phase modifiers, and regeneration 2. The power system operation plan support system according to claim 1, wherein a change in at least one of the active power output of the potential energy power source and the change in the operation plan are included as improvement contents.
The system voltage improvement proposal creation unit uses an improvement method that is considered to have little adverse effect on the vibration suppression index, and calculates the total output amount of the renewable energy power source while satisfying both the vibration suppression index standard and the voltage standard. The power system operation plan support system according to claim 1, wherein an improvement plan that can be maximized is created.
2. The power system operation plan support system according to claim 1, wherein the vibration suppression index indicates either unstable vibration of the output or voltage of the renewable energy power source, or voltage maintenance capability of the power system.
2. The power system operation plan support system according to claim 1, wherein the vibration suppression index is calculated by a vibration suppression index calculation unit that receives an analysis section of the power system and calculation target data and outputs a calculation result of the vibration suppression index.
6. The power system operation plan support system according to claim 5, wherein the analysis cross section is created by an analysis cross section creation unit that creates an analysis cross section of the power system by inputting system configuration data, system operation plan data, and system model data.
6. The power system operation plan support system according to claim 5, further comprising a system voltage calculation unit that calculates a bus voltage of the power system using the analysis section, the vibration suppression index improvement plan, and the calculation target data as inputs.
The power system operation plan support system according to claim 7, wherein the system voltage improvement plan creation unit outputs the improvement plan for the bus voltage based on the calculation result of the system voltage calculation unit and the voltage reference.
9. The power system operation plan support according to claim 8, wherein the system voltage improvement plan creation unit creates an improvement plan by inputting operation state change target facility data when the voltage standard of the system stability judgment standard data is not satisfied. system.
The power system according to claim 1, wherein the vibration suppression index improvement plan creation unit creates an improvement plan by inputting operation state change target equipment data when the vibration suppression index criteria of the system stability criterion data are not satisfied. Operation planning support system.
The power system operation planning support system according to any one of claims 1 to 10, wherein the output unit displays information on the created improvement plan.
Vibration suppression index evaluation processing for outputting an evaluation result based on the vibration suppression index of the power system created based on the system stability criterion data;
Using the evaluation result and the data of equipment subject to operation status change as input, the total amount of output of the renewable energy power source specified in the power system to be calculated is maximized while satisfying the vibration suppression index standard of the system stability judgment standard data. a vibration suppression index improvement plan creation process for creating an initial improvement plan for
A system voltage improvement plan creation process for outputting an improvement plan that maximizes the total amount of output of the renewable energy power source while satisfying the voltage standard of the system stability criterion data based on the initial improvement plan;
A power system operation plan support method, including: outputting or displaying information obtained by the vibration suppression index evaluation process, the vibration suppression index improvement plan creation process, and the system voltage improvement plan creation process.
A program that causes a computer installed to execute a procedure for supporting power system operation planning,
A vibration suppression index evaluation procedure for outputting an evaluation result based on the power system vibration suppression index created based on the system stability criterion data;
Using the evaluation result and the data of equipment subject to operation status change as input, the total amount of output of the renewable energy power source specified in the power system to be calculated is maximized while satisfying the vibration suppression index standard of the system stability judgment standard data. A vibration suppression index improvement plan creation procedure for creating an initial improvement plan to
A system voltage improvement plan creating procedure for outputting an improvement plan that maximizes the total amount of output of the renewable energy power source while satisfying the voltage standard of the system stability criterion data based on the initial improvement plan;
A program that causes the computer to execute a procedure for outputting or displaying information obtained by the vibration suppression index evaluation procedure, the vibration suppression index improvement plan creation procedure, and the system voltage improvement plan creation procedure.