JP7675626B2 - Power system stabilization system, computer program for power system stabilization system, and power system stabilization method - Google Patents

Description

This embodiment relates to a power system stabilization system, a computer program for the power system stabilization system, and a power system stabilization method that controls multiple power devices that generate and transmit electricity, and maintains stable operation of the power system by performing control such as limiting power supply when an accident such as a lightning strike occurs in the power system.

A power system is made up of power plants, substations, loads, and the electric lines that connect them. A power system is a power equipment network that sends generated power to the loads, and includes power generation equipment and transmission and transformation equipment from the power plant to the load end. Electricity in a power system is generated by power sources such as thermal, nuclear, and hydroelectric power. Electricity generated by multiple power sources is supplied to the loads via transmission and transformation equipment. Stable operation and power quality of a power system are maintained by appropriately controlling multiple power generation equipment and transmission and transformation equipment. Even if an accident occurs in a power system due to a lightning strike or the like, it is preferable that control such as power supply restrictions on the power source be performed appropriately and stable operation of the power system be maintained. A power system stabilization system that controls power equipment installed in a power system is known.

JP 2018-085834 A JP 2020-145880 A JP 2011-061911 A

In recent years, many renewable energy power sources that generate electricity from renewable energy have been introduced. The output of renewable energy power sources may fluctuate sharply in a short period of time depending on weather conditions, etc. A time lag occurs between the time when the power status in the power system is measured and the time when an accident actually occurs in the power system and power equipment is controlled after a system model is created and a control target is selected. If, for example, the output of a renewable energy power source fluctuates sharply during this time lag, the power flow at the time when the power status in the power system is measured and the power flow at the time when the power equipment is actually controlled will be different. For this reason, the power limit of the control target selected using system information at the time when the power status in the power system is measured may be insufficient or excessive for the amount of control required at the time when the power equipment is actually controlled, which is a problem in that it is not possible to accurately stabilize the power system. If the amount of control is insufficient, there is a risk that stable operation of the power system cannot be maintained.

It is possible to shorten the time difference between the time when the power situation in the power system is measured and the time when the power equipment is actually controlled, but to achieve this, it is necessary to speed up the acquisition of system information and improve the processing power of the central processing unit, which would entail a significant increase in costs. Therefore, it is preferable to correct the control amount by adding or reselecting the power equipment to be controlled so that the control amount does not become insufficient.

The present embodiment aims to provide a power system stabilization system, a computer program for a power system stabilization system, and a power system stabilization method that can calculate an appropriate power control amount that reduces shortages and excesses relative to the required control amount.

The power system stabilization system of this embodiment has the following features.
(1) The power system includes a power flow calculation/transient stability calculation unit that performs an analysis and simulation of the stability of the power system when a power source to be controlled is cut off.
(2) A control table setting unit is provided that creates a control table indicating a combination of power sources to be shut off for each accident scenario and a control amount that is the total value of the power generation output of the power sources, based on the results of the analytical simulation performed by the power flow calculation transient stability calculation unit.
(3) A setting information derivation unit is provided which derives a correlation equation which expresses the correlation between the power flow value and the power control amount based on the power source to be cut off for each accident type calculated by the power flow calculation transient stability calculation unit, the control amount, and the power flow value, based on the online calculation actual values including the power source to be cut off for each accident type calculated by the power flow calculation transient stability calculation unit, and the control amount and power flow value.
(4) The setting information derivation unit derives a stepped correlation equation for calculating a power control amount corresponding to a range of power flow values, based on the multiple online calculation result values created up to now.
(5) The setting information derivation unit derives a step-like correlation equation based on control variables related to the online calculation actual value that belongs to the same time zone as the current time, within the range of the power flow value, among the multiple online calculation actual value created up to now.

FIG. 1 is a diagram showing a configuration of a power system stabilization system according to a first embodiment; FIG. 2 is a diagram for explaining a control table of the power system stabilization system according to the first embodiment. FIG. 1 is a diagram for explaining corrective control setting information in the prior art related to the power system stabilization system according to the first embodiment. FIG. 2 is a diagram for explaining a corrected control table of the power system stabilization system according to the first embodiment; FIG. 1 is a diagram showing an example of corrected control setting information in the prior art related to the power system stabilization system according to the first embodiment; FIG. 1 is a diagram showing an example of corrected control setting information of the power system stabilization system according to the first embodiment; FIG. 1 is a diagram for explaining derivation of corrective control setting information of the power system stabilization system according to the first embodiment. FIG. 1 is a diagram for explaining corrected control setting information of the power system stabilization system according to the first embodiment. FIG. 1 is a diagram showing a program flow of a central processing unit according to a first embodiment. FIG. 1 is a diagram showing a program flow of a central control device according to a first embodiment. FIG. 1 is a diagram showing an example of corrected control setting information of a power system stabilization system according to a first modified example of the first embodiment; FIG. 13 is a diagram showing an example of corrected control setting information of a power system stabilization system according to a second modification of the first embodiment; FIG. 1 is a diagram showing a configuration of a power system stabilization system according to a second embodiment;

[1. First embodiment]
[1-1. Overall configuration]
As an example of the present embodiment, a power system stabilization system 1 will be described with reference to FIG. 1. As an example, the power system stabilization system 1 is composed of a central processing unit 10, an accident detection terminal unit 20, a control terminal unit 30, and a central control unit 40. The power system stabilization system 1 is connected to a power system 9 and a power supply information network 8. The central processing unit 10 may be referred to as a "central processing unit (pre-processing unit)", and in this case, the central control unit 40 may be referred to as a "central processing unit (post-processing unit)". Note that the central processing unit 10 and the central control unit 40 may be configured as a single unit by integrating their respective functions (for example, Patent Document 3). In this embodiment, the accident detection terminal unit 20 and the control terminal unit 30 may be collectively referred to as terminal units. The control amount of the power supply limit calculated using the corrected control setting information D12 calculated by the setting information derivation unit 202 described later is referred to as a "power supply control amount". In addition, a power supply to be cut off to stabilize the power system 9 may be referred to as a "power supply to be controlled", "power supply to be controlled", "power supply to be controlled", or simply "power supply control target" or "control target".

(Power system 9)
The power system 9 is a power supply network that supplies power generated by a power source to a load. The power system 9 is composed of a plurality of power devices that generate and transmit power. The power devices include, for example, a power source, a circuit breaker, a disconnecting switch, a bus bar, a transmission line, a transformer, and a phase modifying device (not shown in the figure).

The power source is a power generation facility that generates and outputs electric power. The power source is a generator that generates electric power using hydroelectric power, thermal power, nuclear power, etc. The power source may be a renewable energy power source that generates electric power using renewable energy such as wind power or solar power. Multiple power sources are arranged in the power system 9.

A circuit breaker is a device that interrupts the flow of electricity generated by a power source and transmitted through a transmission line, a transformer, and a busbar. When limiting the power supply in the power system stabilization system 1, the power supply is cut off from the power system 9 by controlling the circuit breaker. The circuit breaker is controlled by the central control device 40 via the control terminal device 30. When the circuit breaker is controlled, power supply limitation (hereinafter referred to as power control) is performed in the power system 9.

"Power control" refers to cutting off a power source from the power grid 9. "Power control" may also be called "shutdown" or "disconnection." "Power control amount" refers to the output power of the power source that is being controlled. "Power control amount" may also be called "control amount."

(Power supply information network 8)
The power supply information network 8 is usually composed of a dedicated communication line using microwave radio or optical fiber. Communication is performed between a measuring device (not shown in the figure) installed in the power system 9 and a central processing unit 10 via the power supply information network 8. The measuring device measures the status of power equipment such as power sources, circuit breakers, disconnecting switches, bus bars, transmission lines, and transformers. The measuring device is installed in a substation or a power plant. System information D81 measured by the measuring device is transmitted to the central processing unit 10 via the power supply information network 8. The power supply information network 8 may be one that performs communication via a wired line or one that performs communication via a wireless line.

(Accident detection terminal device 20)
The accident detection terminal device 20 is a terminal device configured with digital relays for a contact information input circuit, a voltage/current input circuit, an active power measurement circuit, a transmission/reception circuit, etc. The accident detection terminal device 20 transmits system information D21 and accident information D22 in the power system 9 to the central control device 40. A plurality of accident detection terminal devices 20 are arranged in substations etc. that can detect assumed accidents.

The system information D21 is information on the connection state of the power system 9 and the supply and demand state of power detected by the accident detection terminal device 20. The system information D21 includes, for example, on/off information of power devices in the power system 9 and measurement information on the supply and demand state of power. The on/off information is information indicating the continuity and interruption of circuit breakers, disconnectors, etc. The measurement information includes information on the output of the power source, the load, the transmission line, the transformer, the active power flowing through the bus (hereinafter referred to as the power flow value), and the bus voltage of each electric power station. The accident detection terminal device 20 captures on/off information of circuit breakers, disconnectors, etc. through the contact information input circuit. In addition, the active power measurement circuit uses the voltage and current information captured through the voltage and current input circuit to measure the active power of the power source output, load, and transmission line, and creates the system information D21.

The accident information D22 is information about an accident that has occurred in a power device in the power system 9. For example, if an accident occurs in a power transmission line, the information indicates the power device involved in the accident and the nature of the accident. The accident detection terminal device 20 inputs, via a contact information input circuit, for example, an operation signal of an accident removal relay (a protective device installed in the power system, not shown in the figure) and on/off information of a circuit breaker, and creates the accident information D22.

(Control Terminal Device 30)
The control terminal device 30 is a terminal device in which a contact information input circuit, a contact information output circuit, a voltage/current input circuit, an active power measuring circuit, a transmitting/receiving circuit, etc. are configured using digital relays. The control terminal device 30 controls a circuit breaker using the contact information output circuit based on a control command D44 received from the central control device 40, and cuts off the designated power source from the power grid 9. The control terminal device 30 outputs system information D31. A plurality of control terminal devices 30 are installed at a power plant or the like that has a power source to be controlled.

The system information D31 is information on the connection state of the power system 9 and the supply and demand state of electricity detected by the control terminal device 30. The system information D31 includes, for example, on/off information of power devices in the power system 9 and measurement information on the supply and demand state of electricity. The on/off information is information indicating the conduction or interruption of circuit breakers, disconnectors, etc. The measurement information includes information on the output of the power source, the load, the power flow value, and the bus voltage of each power station. The control terminal device 30 imports on/off information of circuit breakers, disconnectors, etc. through a contact information input circuit. In addition, the control terminal device 30 uses the voltage and current information imported through the voltage and current input circuit to measure the output of the power source, the load, and the active power of the transmission line through an active power measurement circuit, and creates the system information D31.

(Central processing unit 10)
The central processing unit 10 is a device that receives system information D81, creates a control table D13 and corrected control setting information D12 by calculation, and outputs them. The central processing unit 10 is configured with a computer or the like. The central processing unit 10 is connected to the power supply information network 8 and the central control device 40. The central processing unit 10 is installed in a central power supply command center of a general electricity transmission and distribution company, or the like.

Control table D13 is a table that shows the power sources that are subject to electrical control when an accident occurs and the control amount, which is the total value of the output of the power sources. Control table D13 records the power sources that are subject to electrical control and the control amount for all possible accident scenarios.

Corrected control setting information D12 is information that indicates the relationship between the current value of the monitored object and the control amount required to maintain stable operation of the power system when an accident occurs. Corrected control setting information D12 is created for all possible accident scenarios.

The central processing unit 10 has a system information acquisition unit 101, a system model creation unit 102, a selection target list creation unit 103, a power flow calculation transient stability calculation unit 104, a control table setting unit 105, an online calculation performance information recording unit 201, a setting information derivation unit 202, and a setting information recording unit 203. The system information acquisition unit 101, the system model creation unit 102, the selection target list creation unit 103, the power flow calculation transient stability calculation unit 104, the control table setting unit 105, the online calculation performance information recording unit 201, the setting information derivation unit 202, and the setting information recording unit 203 are configured by a calculation unit in a computer or a software module.

Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integrated circuit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware.

The central processing unit 10 also has a memory unit 204, a memory unit 205, and a memory unit 206. The memory units 204, 205, and 206 are configured with storage media such as semiconductor memory and hard disks. The memory unit 204 stores online calculation performance information D11. The memory unit 205 stores correction control setting information D12. The memory unit 206 stores a control table D13.

Some or all of these components may be composed of, for example, a hard disk drive (HDD), flash memory, electrically erasable programmable read only memory (EEPROM), read only memory (ROM), or random access memory (RAM).

In the following description, the processes executed by each of the system information acquisition unit 101, system model creation unit 102, selection target list creation unit 103, power flow calculation transient stability calculation unit 104, and control table setting unit 105 may be referred to as online pre-calculation or online calculation.

The system information acquisition unit 101 is connected to the power supply information network 8. The system information acquisition unit 101 receives system information D81 from the power supply information network 8 at a predetermined cycle. The system information D81 is information on the connection state of the power system 9 and the power supply and demand state. The system information D81 includes, for example, on/off information of power devices in the power system 9 and measurement information on the power supply and demand state. The on/off information is information indicating the conduction or cutoff of circuit breakers and disconnectors. The measurement information includes information on the output of the power source, the load, the power flow value, and the busbar voltage of each power station. The system information acquisition unit 101 transmits the received system information D81 to the system model creation unit 102.

The system model creation unit 102 creates a system model based on the system information D81 received by the system information acquisition unit 101. The system model is data that models the power system 9. The system model creation unit 102 transmits the created system model to the selection target list creation unit 103.

The selection target list creation unit 103 creates a selection target list based on the system information D81. The selection target list is a list of power sources that can be controlled. The selection target list creation unit 103 creates a selection target list by determining whether or not the power source in which the control terminal device is installed can be controlled based on the operating state of the power source, and transmits the selection target list to the power flow calculation transient stability calculation unit 104. The operating state of the power source refers to the on/off state of the circuit breaker, the magnitude of the power source output, etc.

The power flow calculation transient stability calculation unit 104 performs an analysis simulation based on the system model created by the system model creation unit 102 and the selection target list created by the selection target list creation unit 103. The power flow calculation transient stability calculation unit 104 performs an analysis simulation for stability when an accident occurs in the power system, and if the result is unstable, adds power sources to be controlled sequentially, and determines the control content (combination of power sources to be controlled) that will result in a stable result. The analysis simulation is performed by transient stability calculation for the behavior of the power system 9 when the power source to be controlled is cut off. The power flow calculation transient stability calculation unit 104 transmits the calculated analysis simulation result to the control table setting unit 105 and the online calculation performance information recording unit 201.

The control table setting unit 105 records the analysis simulation results calculated by the power flow calculation transient stability calculation unit 104 in the control table D13. The control table D13 is a table showing the power sources to be controlled when an accident occurs and the control amount, which is the total value of the output of the power sources. The control table D13 records the power sources to be controlled and the control amount for all expected accident modes. The control table setting unit 105 creates a control table D13 that shows the combination of power sources to be cut off and the control amount that maintains the stability of the power system when an accident occurs, based on the analysis simulation performed by the power flow calculation transient stability calculation unit 104. The control table setting unit 105 stores the control table D13 in the memory unit 206.

The memory unit 206 is configured as a database. The memory unit 206 accumulates and stores the control table D13 created by the control table setting unit 105. The control table D13 stored in the memory unit 206 is transmitted to the central control device 40.

The online calculation performance information recording unit 201 creates online calculation performance information D11 based on the analysis simulation results calculated by the power flow calculation transient stability calculation unit 104 and the control table D13 created by the control table setting unit 105. The online calculation performance information D11 is information that indicates each of the analysis simulation results periodically obtained by online pre-calculation.

The online calculation performance information D11 includes each of the results of the analysis simulation as an online calculation performance value. The online calculation performance information D11 is, for example, information that associates the monitored power flow value with information on the content of control. The online calculation performance information recording unit 201 transmits the online calculation performance information D11 to the setting information derivation unit 202 and stores it in the memory unit 204.

The storage unit 204 is configured as a database. The storage unit 204 accumulates and stores the online calculation performance information D11 created by the online calculation performance information recording unit 201. The online calculation performance information D11 stored in the storage unit 204 is transmitted to the setting information derivation unit 202.

The setting information derivation unit 202 derives corrected control setting information D12 based on the online calculation result information D11 created by the online calculation result information recording unit 201 and accumulated and stored in the storage unit 204. The corrected control setting information D12 is information indicating the relationship between the power flow value of the monitored object and the power control amount required to maintain stable operation of the power system when an accident occurs. The corrected control setting information D12 is created for all assumed accident situations. The setting information derivation unit 202 derives corrected control setting information D12 for calculating the power control amount from the power flow value based on the control amount calculated by the power flow calculation transient stability calculation unit 104 and the online calculation result value including the power flow value of the monitored object in the system model used in the analysis simulation. The setting information derivation unit 202 derives a stepwise correlation equation between the power flow value and the control amount for calculating the control amount corresponding to the power flow value range based on multiple online calculation result values created up to now. The settling information derivation unit 202 transmits the corrected control settling information D12 to the settling information recording unit 203.

The setting information recording unit 203 stores the correction control setting information D12 derived by the setting information derivation unit 202 in the memory unit 205.

The memory unit 205 is configured as a database. The memory unit 205 stores the corrected control setting information D12 derived by the setting information derivation unit 202. The corrected control setting information D12 stored in the memory unit 205 is transmitted to the central control device 40.

(Central Control Unit 40)
The central control device 40 is a device that selects a power source based on the system information D21, the accident information D22, and the system information D31, and creates and outputs a control command D44 based on the corrected control setting information D12 and the control table D13. The central control device 40 transmits the control command D44 to the control terminal device 30 to shut off the power source to be controlled.

The central control device 40 also creates a control table D42 for backup control in the event that an abnormality occurs in the central processing device 10. The central control device 40 creates a corrected control table D43 that corresponds to the change in tide current. The central control device 40 creates a control command D44 based on the control table D42 for backup control or the corrected control table D43, and transmits it to the control terminal device 30.

The central control device 40 is composed of a digital relay equipped with a transmission/reception circuit, etc. The central control device 40 is connected to the fault detection terminal device 20, the control terminal device 30, and the central processing unit 10. The central control device 40 is installed in a substation of a general electricity transmission and distribution company, etc.

The central control device 40 has a system information acquisition unit 301, a selection target list creation unit 302, a backup control selection unit 303, an anomaly detection unit 304, a control table switching unit 305, a current change detection unit 401, a correction control target determination unit 402, an accident information receiving unit 500, and a control command output unit 600.

Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integrated circuit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware.

The central control device 40 also has a memory unit 306, a memory unit 307, a memory unit 403, a memory unit 404, and a memory unit 405. The memory units 306, 307, 403, 404, and 405 are configured with storage media such as semiconductor memories. The memory unit 306 stores a correlation equation for backup control D41. The memory unit 307 stores a control table for backup control D42. The memory unit 403 stores corrected control setting information D12. The memory unit 404 stores a control table D13. The memory unit 405 stores a corrected control table D43.

Some or all of these components may be composed of, for example, a hard disk drive (HDD), flash memory, electrically erasable programmable read only memory (EEPROM), read only memory (ROM), or random access memory (RAM).

The system information acquisition unit 301 is connected to the accident detection terminal device 20 and the control terminal device 30. The system information acquisition unit 301 receives system information D21 from the accident detection terminal device 20 and system information D31 from the control terminal device 30 at a predetermined cycle. The system information D21 and system information D31 are information related to the connection state of the power system 9 and the power supply and demand state. The system information D21 and system information D31 include, for example, on/off information of power devices in the power system 9 and measurement information related to the power supply and demand state. The system information acquisition unit 301 transmits the received system information D21 and system information D31 to the selection target list creation unit 302 and the current change detection unit 401.

The selection target list creation unit 302 receives system information D21 and system information D31 from the system information acquisition unit 301. The system information D21 and system information D31 include information on the power sources to be controlled in the power system 9. The selection target list creation unit 302 creates a selection target list that is a list of power sources that can be controlled based on the system information D21 and system information D31. The selection target list creation unit 302 transmits the selection target list to the backup control selection unit 303.

The storage unit 306 stores the correlation equation for backup control D41. The correlation equation for backup control D41 is a correlation equation for performing backup control when an abnormality occurs in the central processing unit 10. The correlation equation for backup control D41 is a correlation equation that indicates the relationship between the power flow value and the required control amount. The correlation equation for backup control D41 is set and stored in advance in the storage unit 306 by the operator of the power system stabilization system 1.

The backup control selection unit 303 creates a control table for backup control D42 based on the selection target list received from the selection target list creation unit 302, the system information D21, and the correlation equation for backup control D41 stored in the memory unit 306. The control table for backup control D42 is a list showing the power sources to be controlled by the backup control performed by the central control unit 40 when an abnormality occurs in the central processing unit 10, for each assumed accident scenario. The backup control selection unit 303 stores the control table for backup control D42 in the memory unit 307.

The memory unit 307 stores the control table D42 for backup control created by the backup control selection unit 303.

The tide current change detection unit 401 receives system information D21 and system information D31 from the system information acquisition unit 301. The tide current change detection unit 401 detects a tide current change based on the system information D21 and system information D31. The tide current change detection unit 401 detects a tide current change as a tide current change at a time immediately before a system accident actually occurs and power control is performed, relative to the tide current at the time when the power situation in the power system 9 is measured. The tide current change detection unit 401 transmits the detected tide current change to the correction control target determination unit 402.

The memory unit 403 receives and stores the correction control setting information D12 from the memory unit 205 of the central processing unit 10.

The memory unit 404 receives and stores the control table D13 from the memory unit 206 of the central processing unit 10.

The corrected control target determination unit 402 creates a corrected control table D43 based on the tide change detected by the tide change detection unit 401, the corrected control setting information D12 stored in the memory unit 403, and the control table D13 stored in the memory unit 404. The corrected control table D43 is a table that indicates the power sources that are subject to electrical control in the event of an accident, corresponding to the tide change, and the control amount that is the total output value of the power sources. The corrected control target determination unit 402 stores the corrected control table D43 in the memory unit 405.

The memory unit 405 receives and stores the corrected control table D43 from the correction control target determination unit 402.

The abnormality detection unit 304 detects abnormalities in the central processing unit 10. The abnormality detection unit 304 monitors online calculation processing by the central processing unit 10, and detects abnormalities in transmission and calculation that occur during the online calculation processing. The abnormality detection unit 304 transmits the detected abnormality to the control table switching unit 305. An abnormality in the central processing unit 10 is detected, for example, when the control table D13 cannot be received from the central processing unit 10.

The control table switching unit 305 selects one of the corrected control table D43 stored in the memory unit 405 and the control table for backup control D42 stored in the memory unit 307, and transmits it to the control command output unit 600. If an abnormality is detected by the abnormality detection unit 304, the control table for backup control D42 is selected, and if no abnormality is detected by the abnormality detection unit 304, the corrected control table D43 is selected.

The accident information receiving unit 500 receives accident information D22 from the accident detection terminal device 20 and transmits it to the control command output unit 600. The accident information D22 includes the location of the accident and the nature of the accident.

The control command output unit 600 receives accident information D22 from the accident information receiving unit 500 and outputs a control command D44. The control command output unit 600 determines the accident status of the control object based on the accident information D22 received from the accident information receiving unit 500, selects the control object based on the corrected control table D43 or the backup control table D42 selected by the control table switching unit 305, and creates a control command D44. The control command output unit 600 transmits the control command D44 to the control terminal device 30.

The above is the configuration of the power system stabilization system 1 according to this embodiment.

[1-2. Effect】
Next, an overview of the operation of the power system stabilization system 1 of this embodiment will be described with reference to Figures 1 to 10. Figure 9 is a diagram showing a program flow when the central processing unit 10 is configured with software modules. The program shown in Figure 9 is built into the central processing unit 10. Figure 10 is a diagram showing a program flow when the central control unit 40 is configured with software modules. The program shown in Figure 10 is built into the central control unit 40. The power system stabilization system 1 performs the following operations and calculations.

(Operation of Central Processing Unit 10)
The central processing unit 10 receives the system information D81, and derives and outputs the control table D13 and the corrected control setting information D12 by calculation. The central processing unit 10 receives the system information D81 from the power supply information network 8 at a predetermined cycle, and updates the control table D13 and the corrected control setting information D12 to reflect the latest state of the power system 9.

The control table D13 is created based on the latest state of the power grid 9 according to the grid information D81. The control table D13 is a table showing the power sources that are subject to electrical control when an accident occurs and the control amount that is the sum of the output values of the power sources.

The central processing unit 10 creates online calculation performance information D11 related to the results of the analysis simulation. The online calculation performance information D11 includes each of the results of the analysis simulation as an online calculation performance value. Based on the online calculation performance information D11, corrected control setting information D12 is created. The corrected control setting information D12 is information indicating the relationship between the power flow value of the monitored object and the required power control amount. The operation of the central processing unit 10 is detailed below.

The central processing unit 10 receives system information D81 from the power supply information network 8 at a predetermined cycle using the system information acquisition unit 101. The system information D81 is information related to the connection state of the power system 9 and the supply and demand state of electricity. The state of the power equipment, such as the power source, circuit breaker, disconnector, transmission line, transformer, and busbar, is measured by measuring devices installed in the power system 9, and is transmitted to the central processing unit 10 via the power supply information network 8 as system information D81.

The system information D81 includes, for example, on/off information of power devices in the power system 9 and measurement information related to the supply and demand state of power. The on/off information is information indicating the conduction or interruption of circuit breakers, disconnectors, etc. The measurement information includes information related to the output of the power source, the load, the power flow value, and the bus voltage of each power station. The system information acquisition unit 101 transmits the received system information D81 to the system model creation unit 102. When the central processing unit 10 is configured by a software module, the above processing is executed by step S101.

The central processing unit 10 creates a system model using the system model creation unit 102 based on the system information D81 received by the system information acquisition unit 101. The system model is data that models the power system 9, and is composed of various models that represent nodes and branches, generators, generator control devices, etc.

A node is a representation of a bus, generator, and load in digital form, and has a node number as identification information. Information about a node, such as the active and reactive power of the power source and load, and the bus voltage, corresponding to the node number, is included in the information about the node. A branch is a representation of a power transmission line and transformer in digital form, and has a branch number as identification information. Information about the branch, such as the connected node numbers (start node and end node), the number of operating lines, and impedance, corresponding to the branch number, is included in the information about the branch. Various models representing generators and generator control equipment are set in the generator node. The magnitude of power demand (active power and reactive power), as well as its voltage and frequency characteristics, are set in the load node.

The system model creation unit 102 performs state estimation calculations based on the system information D81 received before the accident and data related to the system equipment, and creates a system model that represents the system state at that time. The data related to the system equipment is set and stored in advance in the central processing unit 10. The system model creation unit 102 transmits the created system model to the selection target list creation unit 103. When the central processing unit 10 is configured by a software module, the above process is executed by step S102.

The central processing unit 10 creates a selection target list based on the system information D81 using the selection target list creation unit 103. The selection target list is a list of power sources that can be controlled. The selection target list is created based on information about the power sources to be controlled that is included in the system information D81.

The information on the power source to be controlled includes the active power output value of the power source to be controlled and information indicating whether the power source can be controlled. For example, a power source that satisfies certain conditions, such as being currently in operation, having a power generation output exceeding a certain value, and not being excluded from being shut off by the grid operator, is considered to be a power source that can be controlled. The selection target list creation unit 103 transmits a selection target list, which is a list of power sources that can be controlled, to the power flow calculation transient stability calculation unit 104. When the central processing unit 10 is configured by a software module, the above process is executed by step S103.

The central processing unit 10 performs an analysis simulation using the power flow calculation and transient stability calculation unit 104 based on the system model created by the system model creation unit 102 and the selection target list created by the selection target list creation unit 103. The analysis simulation is for confirming the stability of the power system 9 when the power source to be controlled is cut off, and is performed using power flow calculation and transient stability calculation. The power flow calculation and transient stability calculation unit 104 first performs a power flow calculation based on the system model created by the system model creation unit 102.

The power flow calculation calculates the power flow values (active power P and reactive power Q) flowing through the transmission lines and transformers, as well as the magnitude V and phase δ of the bus voltage. Based on the results of the power flow calculation, the power flow calculation transient stability calculation unit 104 performs a simulation using transient stability calculation on the behavior of the power system 9 when the power source to be controlled is shut off after an accident occurs.

The simulation is performed for multiple assumed accidents that are set in advance. The power flow calculation transient stability calculation unit 104 changes the selection of the power source to be controlled, and repeatedly performs transient stability calculations to calculate individual power sources and combinations of power sources until it obtains a result in which the system is stable. The power flow calculation transient stability calculation unit 104 transmits the analysis simulation results to the control table setting unit 105 and the online calculation performance information recording unit 201. When the central processing unit 10 is configured by a software module, the above processing is executed by step S104.

The central processing unit 10 uses the control table setting unit 105 to record the analysis simulation results calculated by the power flow calculation transient stability calculation unit 104 in the control table D13. An example of the control table D13 is shown in FIG. 2. The control table D13 is a table that shows the power sources that are subject to electrical control when an accident occurs and the control amount that is the sum of the output values of the power sources. The control table D13 records the contents of all possible accident scenarios.

The control table D13 is periodically updated in preparation for the occurrence of a postulated accident, with online pre-calculation being performed periodically. For example, online pre-calculation is performed every 30 seconds, and the control table D13 is updated. The control table D13 indicates the combination of power sources to be controlled for each postulated accident scenario and the amount of control. The control table setting unit 105 transmits the control table D13 to the online calculation performance information recording unit 201 and stores it in the memory unit 206. When the central processing unit 10 is configured by a software module, the above process is executed by step S105.

The memory unit 206 stores the control table D13 recorded by the control table setting unit 105.

The central processing unit 10 creates online calculation performance information D11 using the online calculation performance information recording unit 201 based on the analysis simulation results calculated by the power flow calculation transient stability calculation unit 104 and the control table D13 recorded by the control table setting unit 105. The online calculation performance information D11 is information indicating each of the analysis simulation results periodically obtained by online pre-calculation. The online calculation performance information D11 includes each of the analysis simulation results as an online calculation performance value. The online calculation performance information D11 is, for example, information that associates the monitored power flow value with information regarding the content of control.

The monitored power flow value is system information that is highly correlated with the severity of the postulated fault, for example, the power flow value (active power) before the fault occurs on the transmission line that is the subject of the postulated fault. The monitored power flow value is calculated by the power flow calculation transient stability calculation unit 104 through power flow calculation using the system information.

The information on the content of control is the content of control for stabilizing unstable phenomena that arise when a hypothetical accident occurs. For example, the information on the content of control is the name of the power source selected as the control target, and information on the amount of power (control amount) that is electrically cut off from the power grid 9 when the power source to be controlled is cut off.

In this embodiment, as an example, the information regarding the content of control is the amount of power that is electrically cut off from the power grid 9 when the power source to be controlled is cut off.

The online calculation performance information recording unit 201 extracts the monitored power flow value from the analysis simulation result calculated by the power flow calculation transient stability calculation unit 104, and extracts the selection result of the control object based on the control table D13 recorded by the control table setting unit 105. The online calculation performance information recording unit 201 creates online calculation performance information D11 every time it extracts the monitored power flow value and the selection result of the control object corresponding to this monitored power flow value. The online calculation performance information recording unit 201 transmits the online calculation performance information D11 to the setting information derivation unit 202 and accumulates and stores it in the memory unit 204. When the central processing unit 10 is configured by a software module, the above process is executed by step S201.

The memory unit 204 accumulates and stores the online computation performance information D11 created by the online computation performance information recording unit 201.

The central processing unit 10 derives corrected control setting information D12 by the setting information derivation unit 202 based on the online calculation result information D11 created by the online calculation result information recording unit 201 and stored in the memory unit 204. The corrected control setting information D12 is information that indicates the relationship between the power flow value of the monitored object and the required amount of power control. The required amount of power control is the total value of the output applied to the power sources that are the subject of power control. The corrected control setting information D12 is created for all expected accident situations.

In conventional technology, the relationship between the monitored power flow value for each assumed accident scenario and the required control amount in the corrected control setting information D12 was generally expressed by a linear equation. For example, in conventional technology, the relationship between the monitored power flow value and the required control amount was expressed by a linear correlation equation such as y = ax + b. x is the monitored power flow value, and y is the required control amount. a and b are coefficients. Figure 3 shows the relationship between the monitored power flow value for each assumed accident scenario and the required control amount in conventional technology.

The calculation of the power control amount in the conventional technology will be explained with reference to FIG. 5. In FIG. 5, L0 is an approximate line that represents the relationship between the monitored power flow value and the required control amount. The approximate line L0 is calculated by the least squares method or the like based on the online calculation performance information D11 stored in the memory unit 204. In FIG. 5, multiple white circles are online calculation performance values and represent each piece of online calculation performance information D11. The approximate line L0 represents an approximation of the relationship between the monitored power flow value and the required control amount.

In the prior art, a straight line obtained by translating the approximate straight line L0 was used as the corrected control setting information L1. The straight line that is applied to the corrected control setting information L1 is created so as to have a large control amount that is the strictest value for the monitored power flow value that is a lump for the required control amount while maintaining the slope of the approximate straight line L0. The created straight line was used as the corrected control setting information L1. The corrected control setting information L1 is used to calculate the power control amount based on the monitored power flow value.

When calculating the power control amount based on the corrected control setting information L1 shown in Figure 5, the control amount will be excessive for the monitored power flow value. As shown by the distribution of white circles, which are online calculation performance values, the relationship between the actual monitored power flow value and the power control amount is distributed in a stepped manner, so when the required power control amount that exceeds the control amount in all of the online calculation performance information D11 is calculated using a straight line on the corrected control setting information L1, the power sources to be controlled are selected so that the control amount further exceeds the power control amount. For this reason, the control amount, which is the total output of the power sources to be controlled, will be larger than the control amount of the online calculation performance information D11. In Figure 5, the control amount, which is the total output of the power sources to be controlled, is shown by a black circle, and the control amount of each online calculation performance information D11 is shown by a white circle.

The amount of electrical control is calculated based on a straight line that fits the corrected control setting information L1. However, there is a difference M0 between the amount of electrical control and the minimum control amount. There is also a difference M1 between the required control amount and the amount of electrical control. This is because the power source to be subjected to electrical control is selected so that it exceeds the required control amount.

In the example of Figure 5, when calculating the power control amount based on the straight line on the corrected control setting information L1, the ideal control amount corresponding to the monitored power flow value P2 is C1. However, since the output of power sources that can be selected as power control targets is a large discrete value, there is no combination of power sources for which the control amount is C1. For this reason, of the combinations of power sources for which the control amount is C1 or more, the combination of power sources with the control amount closest to C1 is selected.

In the example of Figure 5, C2 is selected as the control amount corresponding to the power source combination whose control amount is closest to C1. In the vicinity of the monitored power flow value P2, C2 is selected as the control amount. As a result, the power control amount becomes excessive compared to the required control amount.

In addition, a control target may be selected for a monitored power flow value that is determined to be stable without shutting off the power source. In FIG. 5, the region 0≦x≦P1 is a region determined to have no control target based on online calculation performance information D11. However, if a power source to be controlled is selected based on a straight line on corrected control setting information L1, the required control amount in the region 0≦x≦P1 will be a positive value, and a control target corresponding to the required control amount will be selected. Of the required control amounts corresponding to the monitored power flow value, the control amounts corresponding to the regions M0 and M1 shown by hatching in FIG. 5 are unnecessary and excessive control.

In this way, in the power system stabilization system 1 of the conventional technology, a correlation equation based on the corrected control setting information L1 is created so as to avoid undercontrol even during a sudden change in power flow, and corrected control information is created using the correlation equation based on the corrected control setting information L1, and corrective control is performed. Since the correlation equation based on the corrected control setting information L1 is a linear equation, if a power control amount with a margin is calculated so as to avoid undercontrol, the control amount will be excessive. Furthermore, if there are few data samples used to determine the correlation equation, a correlation equation with low accuracy is created, and there is a concern that the accuracy of the power control amount will decrease. The data samples used to determine the correlation equation are the actual values of the corrected control information calculated by online calculation.

To improve the above problem, the setting information derivation unit 202 in this embodiment calculates the control amount based on the correlation equation related to the corrected control setting information D12, which has a power control amount set in stages corresponding to the monitored power flow value, instead of the correlation equation related to the corrected control setting information L1.

The setting information derivation unit 202 in this embodiment derives corrected control setting information D12 based on the online calculation result information D11 created by the online calculation result information recording unit 201 and stored in the storage unit 204. The corrected control setting information D12 is information that expresses the relationship between the monitored power flow value and the power control amount using a stepped correlation equation.

The setting information derivation unit 202 creates a step-like function based on the maximum control amount in the range of the power flow value from among the multiple online calculation result values related to the online calculation result information D11 created up to now, calculates the power control amount, and creates a step-like correlation equation.

An example of the corrected control setting information D12 derived by the setting information derivation unit 202 is shown in FIG. 6. The derivation of the corrected control setting information D12 by the setting information derivation unit 202 will be described with reference to FIG. 7. FIG. 7 shows the derivation process of the corrected control setting information D12. The vertical axis of FIG. 7 indicates the controlled variable, and the horizontal axis indicates the monitored power flow value.

Based on the online calculation result information D11 created by the online calculation result information recording unit 201, individual online calculation result values are plotted as shown in FIG. 7. The white circles in FIG. 7 are individual online calculation result values. The electrical control amount equal to or greater than each online calculation result value is derived in stages as corrective control setting information D12. In FIG. 7, NO is the electrical control amount applied to the corrective control setting information D12.

In Figure 7, L1 indicates the corrected control setting information according to the conventional technology. The corrected control setting information L1 according to the conventional technology was expressed as a correlation equation using a linear expression such as y = a x + b. x is the monitored power flow value, and y is the required control amount. a and b are coefficients.

The setting information derivation unit 202 in this embodiment derives a correlation equation having a stepwise set amount of electrical control control corresponding to the monitored current value as the corrected control setting information D12, instead of the corrected control setting information L1. As shown in FIG. 8, the corrected control setting information D12 indicates the correlation between the monitored current value P for each assumed accident state and the total (control amount) of the generator output of the electrical control object, and also indicates the correlation between the monitored current value P and the required control amount. The correlation equation between the monitored current value P and the required control amount is expressed by a step-like correlation equation such as y = 0 (0 < x ≦ P1), y = C0 (P1 < x ≦ P2), ....

The setting information derivation unit 202 derives corrected control setting information D12 that indicates the relationship between the monitored power flow value and the power control amount according to the point (hereinafter referred to as the rising point) at which the required control amount in the online calculation result information D11 exceeds a predetermined threshold and changes in a stepwise manner.

In addition, when the online calculation performance information D11 is small, for example because data on the monitored current value and the required control amount is not sufficiently accumulated, the setting information derivation unit 202 pre-sets corrected control setting information D12 indicating the relationship between the monitored current value and the power control amount based on the required control amount that is set in advance.

The setting information derivation unit 202 derives corrected control setting information D12 that sets a constant electrical control amount corresponding to the selection result of the control target shown in the online calculation result information D11 from the rising point to the next rising point in the online calculation result information D11. As a result, an appropriate electrical control amount is selected that reduces excessive control amounts such as the control amounts corresponding to the regions M0 and M1 in FIG. 5 compared to the electrical control amount based on the corrected control setting information L1 in the conventional technology.

The setting information derivation unit 202 transmits the derived correction control setting information D12 to the setting information recording unit 203. When the central processing unit 10 is configured by a software module, the above process is executed by step S202.

The central processing unit 10 causes the setting information recording unit 203 to store the correction control setting information D12 derived by the setting information derivation unit 202 in the memory unit 205. When the central processing unit 10 is configured by a software module, the above process is executed in step S203.

The memory unit 205 stores the correction control setting information D12 derived by the setting information derivation unit 202.

(Operation of the central control device 40)
The central control device 40 selects a power source based on the system information D21, the accident information D22, and the system information D31, and creates and outputs a control command D44 based on the corrected control setting information D12 and the control table D13. The central control device 40 transmits the control command D44 to the control terminal device 30 to shut off the power source to be controlled.

The central control device 40 also creates a control table D42 for backup control to be used for backup control when an abnormality occurs in the central processing device 10. The central control device 40 creates a corrected control table D43 that corresponds to the change in tide current. The central control device 40 creates a control command D44 based on the control table D42 for backup control or the corrected control table D43, and transmits it to the control terminal device 30.

The central control device 40 periodically receives system information D21 from the accident detection terminal device 20 and system information D31 from the control terminal device 30, detects the latest state of the power system 9, performs corrections to prevent power shortage control in the event of a sudden change in the current, and updates the selection result of the control target.

When a predicted accident actually occurs, the central control device 40 transmits a control command D44 to the control terminal device 30 to shut off the power source that is to be controlled based on the control table D13 created in advance by the central processing unit 10.

As a backup control function, when an abnormality occurs in the central processing unit 10, the central control unit 40 creates a control command D44 to shut off the power source to be controlled based on a control table D42 for backup control that was created in advance, and transmits the control command D44 to the control terminal unit 30. When an abnormality occurs in the central processing unit 10, the central control unit 40 substitutes the control table D42 for backup control, creates a control command D44 based on the control table D42 for backup control, and transmits the control command D44 to the control terminal unit 30.

The central control device 40 receives system information D21 from the accident detection terminal device 20 and system information D31 from the control terminal device 30 at a predetermined cycle via the system information acquisition unit 301. The system information D21 and system information D31 are information related to the connection state of the power system 9 and the supply and demand state of electricity.

The accident detection terminal device 20 arranged in the power system 9 measures the state of the power equipment in the electric station where the accident detection terminal device 20 is installed, and transmits the state to the central control device 40 as system information D21. The control terminal device 30 arranged in the power system 9 measures the state of the power equipment in the electric station where the control terminal device 30 is installed, and transmits the state to the central control device 40 as system information D31. Information relating to the system information D21 and information relating to the system information D31 may overlap.

System information D21 and system information D31 are information related to the connection state of the power system 9 and the power supply and demand state. System information D21 and system information D31 include, for example, on/off information of power devices in the power system 9 and measurement information related to the power supply and demand state.

On/off information is information indicating the continuity or interruption of circuit breakers, disconnectors, etc. Measurement information includes information on the power source output, load, power flow value, and bus voltage of each power station. The system information acquisition unit 301 transmits the received system information D21 and system information D31 to the selection target list creation unit 302 and power flow change detection unit 401. When the central control unit 40 is configured by software modules, the above processing is executed by step S301.

The central control device 40 receives the system information D21 and system information D31 from the system information acquisition unit 301 by the selection target list creation unit 302. The system information D21 and system information D31 include information on the power sources to be controlled in the power system 9. The selection target list creation unit 302 creates a selection target list, which is a list of power sources that can be controlled, based on the system information D21 and system information D31. A controllable power source is a power source that satisfies a specified condition, for example, a power source that is currently in operation, has an output exceeding a specified value, and has not been excluded from being shut off by the system operator. The selection target list creation unit 302 transmits the selection target list to the backup control selection unit 303. When the central control device 40 is configured by a software module, the above process is executed by step S302.

The storage unit 306 stores a correlation equation for backup control D41. The correlation equation for backup control D41 is a correlation equation for performing backup control when an abnormality occurs in the central processing unit 10. The correlation equation for backup control D41 is a correlation equation that indicates the relationship between the power flow value and the required control amount. The correlation equation for backup control D41 is set and stored in the storage unit 306 in advance by the operator.

The correlation equation for backup control D41 is, for example, a correlation equation that expresses the relationship between the power flow value and the required control amount for each assumed accident situation using a linear equation such as y = ax + b. x is the power flow value of the accident point transmission line, and y is the required control amount y. a and b are coefficients. The coefficient a and intercept b are stored as setting values in the memory unit 306.

The central control device 40 creates a control table D42 for backup control using the backup control selection unit 303 based on the selection target list received from the selection target list creation unit 302 and the backup control correlation equation D41 stored in the storage unit 306. The control table D42 for backup control is a list showing the power sources to be controlled for each assumed accident scenario used in backup control when an abnormality occurs in the central processing device 10.

The backup control selection unit 303 calculates the required control amount based on the backup control correlation equation D41, selects a control object based on the selection object list created by the selection object list creation unit 302 so that the control amount exceeds the required control amount, and creates a control table for backup control D42. The backup control selection unit 303 stores the control table for backup control D42 in the storage unit 307. When the central control device 40 is configured by a software module, the above process is executed by step S303.

The memory unit 307 stores the control table D42 for backup control created by the backup control selection unit 303.

The central control device 40 receives system information D21 and system information D31 from the system information acquisition unit 301 via the tidal current change detection unit 401. The tidal current change detection unit 401 detects a tidal current change based on the system information D21 and system information D31. A tidal current change is a change between the tidal current at the time when the online pre-calculation is performed, when the power situation in the power system 9 is measured, and the tidal current immediately before the time when the power equipment is actually controlled.

The tidal current change detection unit 401, for example, compares the tidal current cross section used when creating the system model used in the online pre-calculation with the current tidal current cross section, and detects a tidal current change if the tidal current has increased since the online pre-calculation. The detection of tidal current changes is performed repeatedly at regular intervals, for example, every second. The tidal current change detection unit 401 transmits the detected tidal current change to the correction control target determination unit 402. When the central control unit 40 is configured by a software module, the above process is executed by step S401.

The memory unit 403 receives and stores correction control setting information D12 from the memory unit 205 of the central processing unit 10.

The memory unit 404 receives and stores the control table D13 from the memory unit 206 of the central processing unit 10.

The central control device 40 creates a corrected control table D43 using the corrected control target determination unit 402 based on the tide current change detected by the tide current change detection unit 401, the corrected control setting information D12 stored in the memory unit 403, and the control table D13 stored in the memory unit 404. The corrected control table D43 is a table that indicates the power sources that are subject to electrical control in the event of an accident, corresponding to the tide current change, and the control amount that is the total output of the power sources. The corrected control target determination unit 402 stores the corrected control table D43 in the memory unit 405.

The correction control target determination unit 402 receives the tide change detected by the tide change detection unit 401, and corrects the control target if the control amount for the correction control is greater than the control amount recorded in the control table D13. Specifically, the correction control target determination unit 402 refers to the correction control setting information D12 stored in the memory unit 403, adds generators to be controlled so that the control amount is greater than the required control amount, corrects the control table D13, and creates a corrected control table D43.

An example of the corrected control table D43 is shown in Figure 4. The corrected control table D43 is a table that shows the power sources that are subject to electrical control when an accident occurs and the control amount, which is the total output of the power sources. The corrected control table D43 is created for all possible accident scenarios.

If the tidal current change detection unit 401 does not detect an increase in tidal current, the correction control target determination unit 402 does not correct the control table D13 created by the central processing unit 10, and stores it in the storage unit 405 as a corrected control table D43. If the central control unit 40 is configured by a software module, the above process is executed by step S402.

The memory unit 405 receives and stores the corrected control table D43 from the correction control target determination unit 402.

The central control unit 40 detects abnormalities in the central processing unit 10 by the abnormality detection unit 304. The abnormality detection unit 304 monitors the online calculation processing by the central processing unit 10 and detects abnormalities in transmission and calculation that occur during the online calculation processing.

The abnormality detection unit 304 detects, for example, an abnormality in the reception of the system information D81 in the system information acquisition unit 101, or an abnormality in the online pre-calculation processing in the power flow calculation transient stability calculation unit 104. The abnormality detection unit 304 transmits the detected abnormality to the control table switching unit 305. When the central control device 40 is configured by a software module, the above process is executed by step S304.

The central control device 40 uses the control table switching unit 305 to select one of the corrected control table D43 stored in the memory unit 405 and the control table for backup control D42 stored in the memory unit 307, and transmits it to the control command output unit 600. If an abnormality is detected by the abnormality detection unit 304, the control table for backup control D42 is selected, and if no abnormality is detected by the abnormality detection unit 304, the corrected control table D43 is selected. If the central control device 40 is configured by a software module, the above process is executed by step S305.

The central control device 40 receives accident information D22 from the accident detection terminal device 20 via the accident information receiving unit 500 and transmits it to the control command output unit 600. The accident information D22 includes the location of the accident and the nature of the accident. When the central control device 40 is configured as a software module, the above process is executed by step S500.

The central control device 40 receives accident information D22 from the accident information receiving unit 500 through the control command output unit 600 and outputs a control command D44. The control command output unit 600 determines the nature of the accident that occurred based on the accident information D22 received from the accident information receiving unit 500, selects a control target based on the corrected control table D43 or the backup control table D42 selected by the control table switching unit 305, and creates a control command D44.

The control command output unit 600 creates a control command D44 to shut off the selected power source to be controlled. The control command output unit 600 transmits the control command D44 to the control terminal device 30. When the central control device 40 is configured by a software module, the above process is executed by step S600.

The control terminal device 30 performs control to shut off the power source to be controlled based on the received control command D44.

The above is the operation of the power system stabilization system 1 according to this embodiment.

[1-3. Effects]
(1) According to this embodiment, the central processing unit 10 includes a power flow calculation transient stability calculation unit 104 that performs an analytical simulation of the control amount when a power source to be controlled in the power system 9 is cut off; a control table setting unit 105 that creates a control table D13 that indicates a combination of power sources to be cut off for each accident state and a control amount that is the total value of the power generation output of the power sources based on the analytical simulation performed by the power flow calculation transient stability calculation unit 104; and a setting information derivation unit 202 that calculates a power control amount for a power flow value based on an online calculation result value including the power source to be cut off, the control amount, and the power flow value calculated by the power flow calculation transient stability calculation unit 104. The setting information derivation unit 202 derives a stepped correlation equation corresponding to a range of power flow values based on a plurality of online calculation result values created up to now, thereby making it possible to provide a central processing unit 10 that can calculate an appropriate power control amount in which insufficiency and excess are reduced with respect to the required control amount.

According to this embodiment, even if the state of the power grid 9 changes and the required control amount changes suddenly, an appropriate power control amount can be calculated based on the corrected control setting information D12 using a stepped correlation equation. This makes it possible to calculate a power control amount that suppresses excessive control compared to the power control amount calculated using a linear function in conventional technology. Furthermore, even if the number of data items in the online calculation performance information D11 used to calculate the correlation equation is small, the power control amount can be calculated based on a preset stepped correlation equation.

(2) According to this embodiment, the setting information derivation unit 202 creates a stepped correlation equation based on the maximum control amount in the range of power flow values among the multiple online calculation actual values created up to now, and calculates the power control amount. Therefore, it is possible to provide a central processing unit 10 that can calculate an appropriate power control amount that is both reduced insufficiency and reduced in excess of the required control amount.

The setting information derivation unit 202 calculates a constant power control amount corresponding to the selection result of the control target shown in the online calculation result information D11 for the period from the rising point to the next rising point in the online calculation result information D11, and creates corrected control setting information D12. The calculated power control amount is the maximum power control amount within the range of the power flow value, so an appropriate power control amount with reduced shortage is calculated.

[1-4. Modifications]
(1) First Modification In the above embodiment, the setting information derivation unit 202 derives a step-like function expressing the correlation between the power flow value and the power control amount based on the maximum control amount in the range of the power flow value among the multiple online calculation result values related to the online calculation result information D11 created up to now, and creates the derived step-like correlation equation as the corrected control setting information D12. However, the derivation of the step-like correlation equation by the setting information derivation unit 202 is not limited to the above.

The setting information derivation unit 202 may create a stepped correlation equation based on the control amount related to the online calculation result values that belong to the same time zone as the current time within the range of the power flow value among the multiple online calculation result values related to the online calculation result information D11 created up to now, calculate the power control amount, and create the corrected control setting information D12 using the stepped correlation equation.

The operation of the setting information derivation unit 202 according to the first modified example will be described with reference to FIG. 11. The online calculation result values according to the online calculation result information D11 are created by dividing them into time periods, and are accumulated and stored in the storage unit 205. Each of the multiple online calculation result values includes data for a time period.

The case where 24 hours in a day are divided into eight time periods of three hours each will be described. Each time period is divided as shown in FIG. 11(b). For example, when the current time is 16:00, the setting information derivation unit 202 creates a stepped correlation equation based on the control amount related to the online calculation result value related to time period 6, which includes 16:00, to create the corrected control setting information D12.

When there are multiple online calculation actual values for the same time period, the corrected control setting information D12 may be created based on the control amount for the online calculation actual value created at the latest date and time among the online calculation actual values for the same time period.

Alternatively, when there are multiple online calculation actual values for the same time period, the corrected control setting information D12 may be created based on the maximum control amount or the average control amount among the multiple online calculation actual values for the same time period.

If there is no online calculation result value that belongs to the same time period as the current time, the corrected control setting information D12 may be created based on the control amount related to the online calculation result value that belongs to a time period close to the current time.

Time periods may be determined by day of the week, holiday, or season.

The setting information derivation unit 202 creates a stepped correlation equation based on the control amount for the online calculation result value that belongs to the same time zone as the current time within the range of the power flow value among the multiple online calculation result values related to the online calculation result information D11 created up to now, calculates the power control amount, and creates the corrected control setting information D12 using the stepped correlation equation. Since the power control amount is calculated using the correlation between the power flow value and the control amount that reflects the tendency of the system state in that time zone, the power control amount related to the corrected control setting information D12 can be calculated more accurately.

The setting information derivation unit 202 calculates the power control amount based on the online calculation result value that belongs to the same time zone as the current time, so that it is possible to reduce a shortage of the control amount for the power control amount and to reduce an excess of the control amount.

(2) Second Modification The setting information derivation unit 202 may create a stepped correlation equation based on the control amount associated with the online calculation actual value created at a date and time close to the current date and time, within the range of the power flow value, among the multiple online calculation actual values associated with the online calculation actual information D11 created up to now, to calculate the power control amount, and create corrected control setting information D12 using the stepped correlation equation.

The operation of the setting information derivation unit 202 in the second modified example will be described with reference to FIG. 12. Each of the online calculation performance values in the online calculation performance information D11 includes data on the date and time when the values were created.

The online calculation result values shown in FIG. 12(b) are assumed to have been created in the order of A, B, C, ... H, at the date and time closest to the current date and time. The setting information derivation unit 202 creates a stepped correlation equation based on the control amount related to the online calculation result value [A] created at the date and time closest to the current date and time, and creates the corrected control setting information D12.

The setting information derivation unit 202 may create a stepped correlation equation based on the control amount related to a plurality of online calculation result values created at a date and time close to the current date and time, and create the corrected control setting information D12. For example, the setting information derivation unit 202 may create a stepped correlation equation based on the average value of the control amount of a plurality of online calculation result values A, B, and C created at a date and time close to the current date and time, and create the corrected control setting information D12.

Alternatively, the setting information derivation unit 202 may weight each of the online calculation result values A, B, C, ... H in the order of their creation date and time close to the current date and time, create a stepped correlation equation based on the control amount for the multiple online calculation result values, and create the corrected control setting information D12. For example, the setting information derivation unit 202 may multiply each of the online calculation result values A, B, C, ... H by a weighting coefficient set so that the weight of the online calculation result values created on the date and time close to the current date and time is increased, create a stepped correlation equation based on the control amount for the multiple online calculation result values, and create the corrected control setting information D12.

The setting information derivation unit 202 creates a stepped correlation equation based on the control amount for the online calculation result value created at a date and time close to the current date and time within the range of the power flow value among the multiple online calculation result values related to the online calculation result information D11 created up to now, and calculates the power control amount, and creates the corrected control setting information D12 using the stepped correlation equation.Since the power control amount is calculated using the correlation between the power flow value and the control amount in a system state close to the current system state, the power control amount related to the corrected control setting information D12 can be calculated more accurately.

The configuration of power equipment in the power system 9, such as power sources, circuit breakers, disconnecting switches, busbars, transmission lines, transformers, and phase modifying equipment, as well as the power transmission paths, may have changed. For this reason, online calculation results created at a date and time that is not close to the current date and time may not have been created for the current configuration of the power system 9.

The setting information derivation unit 202 calculates the power control amount based on the online calculation result value created at a date and time close to the current date and time for the current configuration of the power system 9, so that the power control amount related to the corrected control setting information D12 can be calculated more accurately. This makes it possible to reduce a shortage of the control amount related to the power control amount and to reduce an excess of the control amount.

[2. Second embodiment]
[2-1. Configuration and Action]
A power system stabilization system 1 according to the second embodiment will be described. The power system stabilization system 1 according to the second embodiment is shown in Fig. 13. The central control device 40 of the power system stabilization system 1 according to the first embodiment has a storage unit 306, but the central control device 40 of the power system stabilization system 1 according to the second embodiment is different in that it does not have the storage unit 306. The other configurations of the power system stabilization system 1 according to the second embodiment are the same as those of the power system stabilization system 1 according to the first embodiment.

The power system stabilization system 1 according to the second embodiment is composed of a central processing unit 10, a fault detection terminal unit 20, a control terminal unit 30, and a central control unit 40. The central processing unit 10 according to the second embodiment has a system information acquisition unit 101, a system model creation unit 102, a selection target list creation unit 103, a power flow calculation transient stability calculation unit 104, a control table setting unit 105, an online calculation performance information recording unit 201, a setting information derivation unit 202, a setting information recording unit 203, a memory unit 204, a memory unit 205, and a memory unit 206.

The central control device 40 according to the second embodiment has a system information acquisition unit 301, a selection target list creation unit 302, a backup control selection unit 303, an anomaly detection unit 304, a control table switching unit 305, a current change detection unit 401, a correction control target determination unit 402, an accident information reception unit 500, a control command output unit 600, a memory unit 307, a memory unit 403, a memory unit 404, and a memory unit 405.

Below, an overview of the operation of the power system stabilization system 1 according to the second embodiment will be described. In the following explanation, operations that differ from those of the power system stabilization system 1 according to the first embodiment will be described. Explanations of operations similar to those of the power system stabilization system 1 according to the first embodiment will be omitted.

The central control device 40 of the power system stabilization system 1 according to the second embodiment receives the corrected control setting information D12 derived by the central processing device 10, sets the corrected control setting information D12 as backup control setting information D45, and creates a control table D42 for backup control based on the backup control setting information D45.

The central control device 40 of the power system stabilization system 1 according to the second embodiment does not have a memory unit 306 that stores the backup control correlation equation D41. The memory unit 403 of the central control device 40 receives and stores the corrected control setting information D12 from the memory unit 205 of the central processing unit 10.

The central control unit 40 creates a control table D42 for backup control using the backup control selection unit 303 based on the selection target list received from the selection target list creation unit 302 and the correction control setting information D12 stored in the storage unit 403. The backup control selection unit 303 sets the correction control setting information D12 as backup control setting information D45, and creates a control table D42 for backup control based on the backup control setting information D45. The control table D42 for backup control is a list showing the relationship between the amount of control required when an abnormality occurs in the central processing unit 10 and the power supply to be controlled.

The backup control selection unit 303 calculates the required control amount using the system information D21 and system information D31 received via the system information acquisition unit 301 and the corrected control setting information D12 stored in the storage unit 403. The backup control selection unit 303 selects a generator to be electrically controlled for backup control so that the control amount exceeds the required control amount using the selection target list received from the selection target list creation unit 302, and creates a control table D42 for backup control and stores it in the storage unit 307. The backup control selection unit 303 may be configured by a software module.

The above is the configuration and operation of the power system stabilization system 1 according to the second embodiment.

[2-2. Effects]
(1) According to the present embodiment, the power system stabilization system 1 includes a central processing unit 10 and a central control unit 40 .

The central processing unit 10 has a power flow calculation transient stability calculation unit 104 that performs an analytical simulation of the control amount when the power source to be controlled in the power system 9 is cut off, a control table setting unit 105 that creates a control table D13 that shows the combination of power sources to be cut off for each accident state and the control amount that is the total value of the power generation output of the power sources based on the analytical simulation performed by the power flow calculation transient stability calculation unit 104, and a setting information derivation unit 202 that calculates the power control amount for the power flow value based on the online calculation actual value including the power source to be cut off, the control amount, and the power flow value calculated by the power flow calculation transient stability calculation unit 104, and creates corrected control setting information D12, and the setting information derivation unit 202 derives a stepped correlation equation that shows the control amount corresponding to the range of the power flow value based on multiple online calculation actual values created up to now.

When the central control device 40 detects a change in the power flow in the power system 9, the central control device 40 has a corrected control target determination unit 402 that corrects the control table D13 created by the control table setting unit 105 based on the corrected control setting information D12 created by the setting information derivation unit 202 to create a corrected control table D43, and controls the power supply using the control amount related to the corrected control table D43 created by the corrected control target determination unit 402.

This makes it possible to provide a power system stabilization system 1 that can calculate an appropriate power control amount that reduces shortages and excesses relative to the required control amount.

According to this embodiment, even if the state of the power system 9 changes and the required control amount changes suddenly, the central control device 40 corrects the control table D13 created by the control table setting unit 105 based on the corrected control setting information D12 created by the setting information derivation unit 202, and controls the power source to be controlled in the power system 9 with an appropriate control amount. This makes it possible to control the power source in the power system 9 with an appropriate control amount that reduces shortages and reduces excesses.

(2) According to this embodiment, the central control device 40 has a backup control selection unit 303 that creates a control table for backup control D42, which is a list of power sources to be electrically controlled by backup control when an abnormality occurs in the central processing device 10, based on the corrected control setting information D12 created by the setting information derivation unit 202. When an abnormality occurs in the central processing device 10, the power sources are controlled based on the control table for backup control D42 created by the backup control selection unit 303. Therefore, even if an abnormality occurs in the central processing device 10, the power sources in the power system 9 can be controlled with an appropriate amount of control.

According to this embodiment, the corrected control setting information D12 is used for backup control, so there is no need to set the backup control setting value through offline analysis. This reduces the workload of the operator of the power system stabilization system 1.

(2) According to this embodiment, the power system stabilization system 1 includes a terminal device that detects changes in the power system 9, and the central control device 40 detects changes in the power system 9 using the terminal device. This allows the power system stabilization system 1 to quickly and accurately detect changes in the power system 9. As a result, even if the power system 9 experiences a sudden change in the power system 9, the power system stabilization system 1 can control the power source in the power system 9 with an appropriate control amount.

3. Other embodiments
Although the embodiments including the modified examples have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as well as in the scope and gist of the invention. The following is an example.

(1) In the above embodiment, the system information acquisition unit 101 receives the system information D81 from the power supply information network 8. However, the system information acquisition unit 101 may receive the system information D81 via another information transmission medium.

Reference Signs List 1: Power system stabilization system 10: Central processing unit 101: System information acquisition unit 102: System model creation unit 103: Selection target list creation unit 104: Power flow calculation transient stability calculation unit 105: Control table setting unit 201: Online calculation result information recording unit 202: Setting information derivation unit 203: Setting information recording unit 204, 205, 206: Storage unit 20: Accident detection terminal device 30: Control terminal device 40: Central control device 301: System information acquisition unit 302: Selection target list creation unit 303: Backup control selection unit 304: Abnormality detection unit 305: Control table switching unit 401: Power flow change detection unit 402: Correction control target determination unit 500: Accident information receiving unit 600: Control command output unit 306, 307, 403, 404, 405: Storage unit 8: Power supply information network 9: Power system

Claims (7)

A power flow calculation and transient stability calculation unit performs analysis and simulation of stability when a fault occurs in the power system;
a control table setting unit that creates a control table indicating a combination of power sources to be shut off in order to maintain the stability of the power system when an accident occurs and a control amount that is a total value of an output of the power sources, based on the analysis simulation performed by the power flow calculation and transient stability calculation unit; and
a setting information derivation unit that derives setting information for calculating a power control amount from the power flow value based on an online calculation result value including the control amount calculated by the power flow calculation transient stability calculation unit and a power flow value related to the analysis simulation,
the setting information derivation unit derives a stepped correlation equation expressing a correlation between a power flow value and a control amount, the step-like correlation equation calculating a control amount corresponding to a range of power flow values based on the plurality of online calculation result values created up to now ;
the setting information derivation unit derives a step-like correlation equation based on a control amount related to the online calculation result value that belongs to the same time zone as the current time within the range of the power flow value, among the plurality of online calculation result values created up to now;
Power system stabilization system. A power flow calculation and transient stability calculation unit performs analysis and simulation of stability when a fault occurs in the power system;
a control table setting unit that creates a control table indicating a combination of power sources to be shut off in order to maintain the stability of the power system when an accident occurs and a control amount that is a total value of an output of the power sources, based on the analysis simulation performed by the power flow calculation and transient stability calculation unit; and
a setting information derivation unit that derives setting information for calculating a power control amount from the power flow value based on an online calculation result value including the control amount calculated by the power flow calculation transient stability calculation unit and a power flow value related to the analysis simulation,
the setting information derivation unit derives a step-like correlation equation expressing a correlation between a power flow value and a control amount, the step-like correlation equation calculating a control amount corresponding to a range of the power flow value based on the plurality of online calculation result values created up to now;
the setting information derivation unit derives a stepped correlation equation based on a control amount related to the online calculation result value created at a date and time close to a current date and time within a range of the power flow value, among the plurality of online calculation result values created up to now;
Power system stabilization system. A power flow calculation and transient stability calculation unit performs analysis and simulation of stability when a fault occurs in the power system;
a control table setting unit that creates a control table indicating a combination of power sources to be shut off in order to maintain the stability of the power system when an accident occurs and a control amount that is a total value of an output of the power sources, based on the analysis simulation performed by the power flow calculation and transient stability calculation unit; and
a setting information derivation unit that derives setting information for calculating a power control amount from the power flow value based on an online calculation result value including the control amount calculated by the power flow calculation transient stability calculation unit and a power flow value related to the analysis simulation,
the setting information derivation unit derives a step-like correlation equation expressing a correlation between a power flow value and a control amount, the step-like correlation equation calculating a control amount corresponding to a range of the power flow value based on the plurality of online calculation result values created up to now;
A central processing unit;
a corrected control target determination unit that corrects the control table created by the control table setting unit based on corrected control setting information created by the setting information derivation unit when a change in power flow in the power system is detected, and creates a corrected control table;
The power supply is controlled based on the power control amount according to the corrected control table created by a corrected control target determination unit.
A central control unit;
A power system stabilization system equipped with the above. The central control device has a backup control selection unit that creates a control table for backup control, which is a list of power sources to be controlled by the backup control when an abnormality occurs in the central processing device, based on the corrected control setting information created by the setting information derivation unit, and when an abnormality occurs in the central processing device, control is performed based on the control table for backup control created by the backup control selection unit.
The power system stabilization system according to claim 3 . the power system stabilization system includes a terminal device for detecting a change in tide flow in the power system;
The central control device detects a change in power flow in the power system by the terminal device.
The power system stabilization system according to claim 3 or 4 . On the computer,
a power flow calculation transient stability calculation step for performing an analytical simulation on stability when a fault occurs in the power system;
a control table setting step of creating a control table showing a combination of power sources to be shut off in order to maintain the stability of the power system when an accident occurs and a control amount which is a sum of outputs of the power sources, based on the analysis simulation performed in the power flow calculation and transient stability calculation step;
a setting information derivation step of deriving setting information for calculating a power control amount from a power flow value based on an online calculation result value including the control amount calculated in the power flow calculation transient stability calculation step and a power flow value related to the analytical simulation;
a correction control target determination step of correcting the control table created in the control table setting step based on corrected control setting information created in the setting information derivation step when a change in power flow in the power system is detected, to create a corrected control table ,
the setting information derivation step derives a stepwise correlation equation expressing a correlation between a power flow value and a control variable, the step calculating a control variable corresponding to a range of power flow values based on the online calculation result values created up to now ;
The power supply is controlled based on the power control amount according to the corrected control table created in the corrected control target determination step .
A computer program for power system stabilization systems. A procedure for power flow calculation and transient stability calculation to perform analysis and simulation of stability when a fault occurs in a power system;
a control table setting step for creating a control table indicating a combination of power sources to be shut off in order to maintain the stability of the power system when an accident occurs and a control amount which is a sum of the outputs of the power sources, based on the analytical simulation performed by the power flow calculation transient stability calculation step;
a setting information derivation step of deriving setting information for calculating a power control amount from the power flow value based on the control amount calculated by the power flow calculation transient stability calculation step and an online calculation result value including a power flow value related to the analytical simulation;
a correction control target determination step of correcting the control table created in the control table setting step based on corrected control setting information created in the setting information derivation step when a change in power flow in the power system is detected, to create a corrected control table;
the setting information derivation step includes deriving a step-like correlation equation expressing a correlation between a power flow value and a control amount, the step-like correlation equation calculating a control amount corresponding to a range of power flow values based on the online calculation result values created up to now;
The power source is controlled by the power control amount according to the corrected control table created by the corrected control target determination procedure .
Power system stabilization method.

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