System stabilization system and system stabilization method

Abstract

The objective of the present invention is to provide a technology that enables appropriate determination of a power generator and a load which are to be controlled, and a control amount with respect to the power generator and load. A system stabilizing system includes a control content calculation unit that, if it is determined, on the basis of a system model, that an overload or an abnormal voltage is to occur, calculates control content including a control target and a control amount of the control target, by optimal power flow calculation, and on the basis of the system model and facility information. The control content includes a cutoff amount, which is a control amount of a generator and / or a load that are to be controlled.

Description

[Technical Field]

[0001] This disclosure relates to a grid stabilization system and a grid stabilization method. [Background technology]

[0002] Various technologies have been proposed for controlling power systems. For example, Patent Document 1 proposes a technology for calculating the reactive power that a power source should output in the event of a fault in a power system. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-21919 [Overview of the project] [Problems that the invention aims to solve]

[0004] When an accident occurs in a power system, protective relay systems are used to eliminate the accident to prevent its effects from spreading over a wide area. However, when transmission lines and transformers are opened as a result, the voltage and power flow conditions in the power system can change rapidly, potentially causing overload and abnormal voltage in the transmission lines. Therefore, to resolve such overload and abnormal voltage, power supply restriction or load restriction is performed by disconnecting generators or loads from the power system using systems stabilization systems or the like.

[0005] However, as power systems become more complex, conventional technology has the problem of not being able to properly determine which generators and loads should be shut off and by what amount.

[0006] Therefore, this disclosure has been made in view of the above-mentioned problems, and aims to provide a technology that can appropriately determine the generator and load to be controlled, and the amount to be controlled. [Means for solving the problem]

[0007] The first grid stabilization system according to this disclosure includes: an acquisition unit that acquires measurement information of a power system including a generator and loads; an accident occurrence determination unit that determines whether or not an accident has occurred in the power system based on the measurement information; a model generation unit that generates a grid model based on the measurement information and the equipment information of the power system when it is determined that an accident has occurred; and a control content calculation unit that, when it is determined that an overload or abnormal voltage has occurred based on the grid model, calculates control content including a control target and a control amount of the control target by optimal power flow calculation with the control amount of the control target as a variable, based on the grid model and the equipment information, wherein the control content includes a break-off amount which is the control amount of at least one of the generator and the load that are the control targets. The system further includes a sensitivity calculation unit that calculates the sensitivity of at least one of the power flow in the power transmission lines of the power system and the voltage of the busbars of the power system based on the control content. .

[0008] The second grid stabilization system according to this disclosure comprises a central computing unit and a slave unit capable of communicating with the central computing unit, wherein the central computing unit includes a first acquisition unit that acquires measurement information of a power system including generators and loads, a model generation unit that generates a grid model for each of the predetermined fault patterns based on the measurement information, equipment information of the power system and a predetermined number of fault patterns, and, when it is determined that an overload or abnormal voltage occurs based on the grid model of the fault pattern, the system generation unit generates a control content including a controlled object and a controlled amount of the controlled object based on the grid model and equipment information, the controlled object The system includes a control content calculation unit that calculates by optimal power flow calculation with control quantities as variables and generates a control table that associates the fault pattern with the control content, wherein the control content includes a break amount which is the control quantity of at least one of the generator and the load that are the controlled objects, and the slave station device includes a second acquisition unit that acquires the measurement information and the control table, a fault occurrence determination unit that determines whether or not the fault pattern in the control table has occurred in the power system based on the measurement information, and a control content determination unit that determines the control content associated with the fault pattern determined to have occurred in the control table. Furthermore, the central processing unit includes a sensitivity calculation unit that calculates the sensitivity of at least one of the power flow in the power transmission lines of the power system and the voltage of the busbars of the power system based on the control content. . [Effects of the Invention]

[0009] According to this disclosure, based on a system model and equipment information, the control content, including the controlled object and the controlled quantity of the controlled object, is calculated by optimal power flow calculation, and the control content includes a break-off quantity, which is at least one of the controlled quantities of the generator and load that are the controlled objects. With such a configuration, the generator and load to be controlled and their controlled quantities can be appropriately determined.

[0010] The purpose, features, aspects, and advantages of this disclosure will become clearer from the following detailed description and accompanying drawings. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing a power grid using the grid stabilization system according to Embodiment 1. [Figure 2] This is a block diagram showing the configuration of the system stabilization system according to Embodiment 1. [Figure 3] This figure shows the concept of the system model according to Embodiment 1. [Figure 4] This is a flowchart showing the operation of the system stabilization system according to Embodiment 1. [Figure 5] This is a block diagram showing the configuration of the system stabilization system according to Embodiment 2. [Figure 6] This figure shows the model used in the sensitivity calculation unit according to Embodiment 2. [Figure 7] This is a block diagram showing the configuration of the system stabilization system according to Embodiment 3. [Figure 8] This is a flowchart showing the operation of the system stabilization system according to Embodiment 3. [Figure 9] This is a schematic diagram showing a power grid using the grid stabilization system according to Embodiment 4. [Figure 10] This is a block diagram showing the configuration of the central processing unit of the system stabilization system according to Embodiment 4. [Figure 11]This is a block diagram showing the configuration of the slave station equipment of the grid stabilization system according to Embodiment 4. [Figure 12] This is a flowchart showing the operation of the central processing unit of the system stabilization system according to Embodiment 4. [Figure 13] This is a flowchart showing the operation of the slave station device of the system stabilization system according to Embodiment 4. [Figure 14] This block diagram shows the hardware configuration of a system stabilization system relating to other variations. [Figure 15] This block diagram shows the hardware configuration of a system stabilization system relating to other variations. [Modes for carrying out the invention]

[0012] <Embodiment 1> Figure 1 is a schematic diagram showing a power system using the grid stabilization system 8 according to this embodiment 1. The power system in Figure 1 comprises a power transmission and distribution system 1, a generator 2, a load 3, a renewable energy source (hereinafter referred to as "renewable energy source") 4, a storage battery 5, a voltage control device 6, a measuring device 7, and a grid stabilization system 8.

[0013] The power transmission and distribution system 1 connects the generator 2, load 3, renewable energy source 4, storage battery 5, and voltage control equipment 6 so that power is transferred between them. The power transmission and distribution system includes, for example, transmission lines and busbars.

[0014] Generator 2 includes at least one of the following types of generators: a nuclear power generator, a thermal power generator, a hydroelectric power generator, etc. In this specification, for example, at least one of A, B, C, ..., and Z means any one of all combinations obtained by selecting one or more types from the groups A, B, C, ..., and Z.

[0015] Load 3 includes, for example, equipment of a consumer that uses power from the power grid. Renewable energy source 4 includes, for example, equipment with inverters such as solar power generators and wind power generators. Storage battery 5 includes, for example, a secondary battery system consisting of lithium-ion batteries, NAS batteries, etc., or at least one of a flywheel battery and an electric double-layer capacitor. Voltage control equipment 6 is voltage control equipment other than renewable energy source 4 and storage battery 5, and includes, for example, phase adjustment equipment and FACTS (Flexile AC Transmission System) equipment such as SVC (Reactive Power Compensator) and STATCOM (Self-Commutated Reactive Power Compensator).

[0016] The measuring device 7 generates measurement information for the power system, including the generator 2, load 3, renewable energy source 4, storage battery 5, and voltage control equipment 6. The measurement information includes, for example, the voltage, current, power, frequency, and switching status of protective relays for each part of the power transmission and distribution system 1.

[0017] A protective relay (not shown) is installed, for example, in the transmission lines, busbars, generators 2, loads 3, and renewable energy sources 4 in the power transmission and distribution system 1. It detects overvoltage, overcurrent, etc., caused by an accident and electrically shuts off the power equipment at the location of the accident to prevent the accident from spreading to a wider area, thereby clearing the accident.

[0018] A power cutoff device or load cutoff device (not shown) is installed, for example, between the power transmission and distribution system 1 and the generator 2, load 3, and renewable energy source 4, and cuts off the connection between the power transmission and distribution system 1 and the generator 2, load 3, and renewable energy source 4 by a commanded amount. In the following description, unless otherwise distinguished, the generator 2, load 3, renewable energy source 4, battery 5, voltage control equipment 6, measuring device 7, power cutoff device, and load cutoff device will be referred to as "equipment."

[0019] The grid stabilization system 8 is connected to the equipment via the communication network shown by the dashed line in Figure 1. Based on the measurement results of the measuring device 7, if the grid stabilization system 8 determines that a fault has occurred in the power system, it calculates the control content, including the control target and the control quantity for the control target, which should be controlled in order to resolve the grid abnormal conditions such as overload and abnormal voltage that occur during fault removal. The grid stabilization system 8 then transmits (commands) the control content to the control target equipment, making it possible to resolve the grid abnormal conditions that occur after the fault has been removed.

[0020] Figure 2 is a block diagram showing the configuration of the system stabilization system 8 according to this first embodiment. The system stabilization system 8 in Figure 2 comprises a communication unit 11 which is an acquisition unit, a recording unit 12, an accident occurrence determination unit 13, a model generation unit 14, and a control content calculation unit 15.

[0021] The communication unit 11 receives and acquires measurement information of the power system sequentially (for example, periodically) from the measuring device 7. The communication unit 11 also transmits (commands) the control content, which is the calculation result of the control content calculation unit 15, to the equipment to be controlled.

[0022] The recording unit 12 records measurement information acquired by the communication unit 11, power system equipment information, calculation results from the control content calculation unit 15, and the equipment's past control history (e.g., history of controlled quantities). The equipment information includes, for example, the connection relationships between equipment and the impedance and reactance between equipment.

[0023] The fault occurrence determination unit 13 determines whether or not a fault has occurred in the power system based on the measurement information. Generally, when a fault occurs in the power system, the voltage, current, and power flow change rapidly, and protective relays activate. For this reason, the fault occurrence determination unit 13 may determine whether or not the protective relays have activated based on the measurement information, and if it determines that the protective relays have activated, it may determine that a fault has occurred in the power system.

[0024] The model generation unit 14 generates a system model based on measurement information and equipment information when the fault occurrence determination unit 13 determines that a fault has occurred. The system model is a model that shows the state of the power system. Conceptually, the system model is as shown in Figure 3. ~ As shown above, it is a model that shows the connection relationships and operating conditions of equipment, including the impedance between equipment, generated power, and consumed power. In reality, a system model includes the impedance between equipment, generated power, and consumed power, and is represented by multiple equations that show the relationships between equipment according to the physical laws of the power system.

[0025] According to the system model, for example, the voltage, current, and power flow status of the power system, the amount of power generated by generator 2, the load amount of load 3, and the operating status of renewable energy source 4, storage battery 5, and voltage control equipment 6 can be calculated. When the model generation unit 14 generates a system model based on measurement information and equipment information when a fault occurs in the power system, a system model is generated in which the transmission lines or transformers are opened to resolve the fault.

[0026] The control content calculation unit 15 determines whether or not an overload or abnormal voltage occurs based on the system model. For example, if the power system state indicated by the system model is a predetermined power system state (for example, a predetermined state where transmission lines are open), the control content calculation unit 15 may determine that an overload or abnormal voltage occurs. Alternatively, for example, if the calculation result of the system model using measurement information indicates predetermined voltage, current, and power flow states, and predetermined operating states of equipment, the control content calculation unit 15 may determine that an overload or abnormal voltage occurs.

[0027] When the control content calculation unit 15 determines that an overload or abnormal voltage has occurred, it calculates the control content, including the controlled object and the controlled quantity of the controlled object, based on the system model and equipment information, using optimal power flow calculation (hereinafter sometimes referred to as "OPF").

[0028] The control includes a tripping amount, which is the control variable of at least one of the generator 2 and load 3 that are being controlled. In other words, the control includes a tripping amount, which is the control variable of at least one of the generator 2 and load 3.

[0029] Furthermore, in this embodiment 1, the control content further includes at least one of the following: the interruption amount, which is the control amount of the renewable energy power source 4 that is the target of control; and the active power and reactive power, which are the control amounts of the renewable energy power source 4, the storage battery 5, and the voltage control device 6 that are the targets of control. In other words, the control content further includes at least one of the following: the interruption amount of the renewable energy power source 4; the active power of the renewable energy power source 4; the reactive power of the renewable energy power source 4; the active power of the storage battery 5; the reactive power of the storage battery 5; the active power of the voltage control device 6; and the reactive power of the voltage control device 6. The calculation of the control content will be explained in detail later.

[0030] The control content calculation unit 15 discretizes the control variable as needed. The discretization of the control variable will be explained in detail later.

[0031] <Calculation of control content> Next, we will explain the calculation of the control content using the OPF in the control content calculation unit 15. The OPF is a calculation that finds the value of the variable that minimizes the objective function, which is expressed by the variable, under the constraints. In the following explanation, the objective function, constraints, and OPF will be explained in this order.

[0032] <Objective Function> In the following explanation, the objective function is represented as f(x,u,z). The variable x is the set of voltage solutions, for example, a voltage vector composed of the magnitude and phase angle of the bus voltage.

[0033] Variable u is a control variable, and is a set of variables that can be controlled by a control system such as the grid stabilization system 8. In this embodiment 1, variable u includes the amount of power cutoff to the generator 2, load 3 and renewable energy source 4 by the power cutoff device or load cutoff device, and the active power and reactive power of the renewable energy source 4, storage battery 5 and voltage control equipment 6.

[0034] The variable z is a dependent variable and is a set of variables determined by the determination of the variable u. For example, the variable z includes the active and reactive power flows of the transmission line, which are determined by the determination of the interruption amounts of generator 2, load 3, and renewable energy source 4.

[0035] The objective function f(x, u, z) according to Embodiment 1 is a function for optimizing a certain item of the power system. Hereinafter, examples of several objective functions will be described.

[0036] <Objective Function of the First Example> The objective function of the first example is an objective function for minimizing the amount of interruption of the generator 2, the load 3, and the renewable power source 4 by the power cut-off device or the load cut-off device, and is expressed as the following formula (1). In the right side of formula (1), the notations of the variables x, u, z are omitted, and the notations of the variables x, u, z may be omitted similarly in the right sides of other formulas. Also, due to the notation constraints in the specification, the characters represented by subscripts in the formula are represented as mere subscripts in the specification.

[0037]

Equation

[0038] R i Gcur , R i Lcur , R i REScur is the amount of interruption of the generator (i), the load (i), and the renewable power source (i). P i G0 , P i L0 , P i RES0 is the rated active power of the generator (i), the load (i), and the renewable power source (i). K G1 , K L1 , K RES1 is the weight coefficient of the objective function. Since the amount of interruption is expressed as the product of the interruption rate and the rated active power, the above objective function may be expressed as the following formula (2).

[0039]

Equation

[0040] R i G , R i L ,R i RES This represents the interruption rate of the generator (i), load (i), and renewable energy source (i).

[0041] <Objective function in the second example> The objective function in the second example is the objective function for minimizing the output change of the renewable energy power source 4, the storage battery 5, and the voltage control equipment 6, whose outputs are controlled by output commands from the grid stabilization system 8, and is expressed as shown in equation (3) below. In this example, the voltage control equipment 6 includes, but is not limited to, phase regulating equipment, SVC, and STATCOM.

[0042]

number

[0043] P i RES ,P i RES0 This represents the active power and steady-state active power of the renewable energy source (i). i ESS ,P i ESS0 These are the active power and steady-state active power of the battery (i). Q i RES ,Q i ESS ,Q i SCShS ,Q i SVC ,Q i STATCOM This is the reactive power of renewable energy sources (i), storage batteries (i), phase adjustment equipment (i), SVC (i), and STATCOM (i). Q i RES0 ,Q i ESS0 ,Q i SCShS0 ,Q i SVC0 ,Q i STATCOM0 This represents the steady-state reactive power of renewable energy sources (i), storage batteries (i), phase-shifting equipment (i), SVC (i), and STATCOM (i). RES,P ,K RES,Q ,K ESS,P ,K ESS,Q ,K SCShR,Q ,K SVC,Q ,K STATCOM,Q This is the weight coefficient of the objective function.

[0044] <Objective function for the third example> The objective function for the third example is the objective function for minimizing the voltage and power flow violations, and is expressed as shown in equation (4).

[0045]

number

[0046] V i vio ,V i ,V i max ,V i min These are the voltage violation amount, voltage, maximum voltage, and minimum voltage of node (i). i vio ,S i ,S i max These are the apparent power flow violation, apparent power flow, and apparent power capacity of transmission line (i). The absolute values ​​of equations (3) and (4) (e.g., |P) i RES0 -P i RES Instead of |), use the square of the number inside the absolute value (for example (P i RES0 -P i RES ) 2 ) may also be used.

[0047] The above describes an example of an objective function according to this embodiment 1, but it is not limited to the above example. For example, the objective function according to this embodiment 1 may be an objective function for minimizing the fuel cost of the generator 2, an objective function for minimizing transmission losses, or an objective function for minimizing the voltage deviation from the target voltage. The objective function may be changed as appropriate according to the user's operational objectives. Furthermore, the objective function according to this embodiment 1 is K A ,K B Using two or more weighting factors such as A (x, u, z), f B Combining two or more objective functions such as A f A (x, u, z) + K B f B (x, u, z) etc. may also be objective functions.

[0048] <Constraints> Constraints (also called constraint equations) are inequalities such as g A (x, u, z) ≤ 0, and at least one of the equations such as h A (x, u, z) = 0. Examples of inequality constraints include the capacity constraints of generator 2, renewable power source 4, and battery 5, and the upper limits of the disconnection amounts of generator 2, load 3, and renewable power source 4. Examples of equation constraints include the power flow equation (also called the state equation).

[0049] Note that constraints substituting for the objective function may be used. For example, instead of using the objective function of the third example, voltage upper and lower limit constraints (V i min ≤ V i ≤ V i max ) and apparent power flow constraints (0 ≤ S i ≤ S i max ) may be used.

[0050] <opf> The objective function and constraint conditions described above are described by parameters that are fixed values in the OPF in addition to the variables x, u, z that are variable values in the OPF. As the parameters that are fixed values, values based on the system model and equipment information are used, such as, for example, constants of power system equipment, line impedances, upper and lower limit values of bus voltages, upper and lower limits of the active power output and reactive power output of Generator 2, and upper and lower limit values of equipment capacities.

[0051] The control content calculation unit 15 performs a calculation to obtain variables x, u, z that minimize the objective function under the constraint conditions by performing OPF. For the solution method of OPF, for example, a simplex method, an interior point method, a primal-dual interior point method, etc. may be used, or metaheuristics such as a genetic algorithm and particle swarm optimization (PSO) may be used, or other solution methods may be used.

[0052] The variables x, u, z obtained by OPF can minimize the objective function. For example, the variables x, u, z obtained by OPF of the objective function combining the objective function of the first example and the objective function of the third example can reduce overload and abnormal voltage by minimizing the disconnection amounts of Generator 2, Load 3, and the renewable energy source 4 and minimizing the voltage violation amount and the power flow violation amount. The variables x, u, z obtained by OPF of the objective function of the first example and the constraint conditions (V i min ≤V i ≤V i max [ 、0≤S i ≤S i max ) can also perform similar minimization and reduction.

[0053] Furthermore, for example, the variables x, u, z obtained by the OPF of the objective function combining the objective function of the second example and the objective function of the third example can reduce overload and abnormal voltage by minimizing voltage violations and power flow violations while minimizing the change from the steady state of the active and reactive power outputs of the renewable energy source 4, storage battery 5, and voltage control equipment 6. The constraints (V) corresponding to the objective function of the second example and the objective function of the third example are... i min ≤V i ≤V i max , 0≦S i ≤S i max The variables x, u, and z obtained by the OPF with ) can also be minimized and reduced in the same way.

[0054] The variable u contains control content including the controlled object and the controlled quantity of the controlled object. In this embodiment 1, it includes the interruption amounts of the generator 2, load 3, and renewable energy source 4, and the active power and reactive power of the renewable energy source 4, storage battery 5, and voltage control device 6. Note that the interruption amount and the interruption rate have a one-to-one relationship and are substantially the same; therefore, the controlled quantity is substantially the same as the interruption amount of the generator 2, load 3, and renewable energy source 4 and the interruption rate of the generator 2, load 3, and renewable energy source 4. For this reason, the interruption amount may be a broad concept that includes the interruption rate.

[0055] The interruption rates of the generator 2, load 3, and renewable energy source 4 obtained by the OPF may be discrete values ​​such as 0 or 1, or continuous values ​​such as 0 to 1. Furthermore, when simulating by aggregating multiple generators 2, load 3, and renewable energy source 4, the interruption amounts of the generators 2, load 3, and renewable energy source 4 obtained by the OPF may be discrete values ​​such as 0, the steady-state value of one piece of equipment, or the sum of combinations thereof, or continuous values ​​such as 0 to the steady-state value after aggregation. In addition, the active power and reactive power of the renewable energy source 4, storage battery 5, and voltage control equipment 6 obtained by the OPF may also be discrete or continuous values.

[0056] <Discretization of the controlled variable> The control content calculation unit 15 discretizes the control quantity as needed. For example, the generator 2, load 3, and renewable energy source 4 will be controlled to either shut off (shutting off rate 1) or not shut off (shutting off rate 0). Also, when multiple generators 2, loads 3, and renewable energy source 4 are aggregated, control will be performed in increments of the shutoff amount corresponding to one piece of equipment. Furthermore, some renewable energy source 4, storage battery 5, and voltage control equipment 6 can output to any value, while others can only adjust the output in discrete values, such as in increments of 10kW. In particular, the phase adjustment equipment of the voltage control equipment 6 can only adjust the output in increments of the capacity of each power capacitor and shunt reactor. In situations like the above, if the control quantity obtained by the OPF is a continuous value, the control content calculation unit 15 may discretize the control quantity and convert it into a discrete value control quantity actually used by the controlled object.

[0057] For example, the control content calculation unit 15 calculates 0≦R i G If <0.5, then R i G Let = 0, and 0.5 ≤ R i G When R is ≤ 1 i G The controlled variable may be discretized by rounding to 1, or it may be discretized using a threshold different from the rounding threshold (0.5).

[0058] <Operation> Figure 4 is a flowchart illustrating the operation of the system stabilization system 8 according to this embodiment 1, i.e., the system stabilization method.

[0059] In step S1, the communication unit 11 sequentially receives and acquires measurement information of the power system from the measuring device 7.

[0060] In step S2, the fault occurrence determination unit 13 determines whether or not a fault has occurred in the power system based on the measurement information. If it is determined that a fault has occurred in the power system, the process proceeds to step S3; otherwise, the process proceeds to step S1.

[0061] In step S3, the model generation unit 14 generates a system model based on the measurement information and equipment information.

[0062] In step S4, the control content calculation unit 15 determines whether an overload or abnormal voltage occurs based on the system model. If it is determined that an overload or abnormal voltage occurs, the process proceeds to step S5; otherwise, the process proceeds to step S1.

[0063] In step S5, the control content calculation unit 15 calculates the control content, including the controlled object and the controlled amount of the controlled object, using the OPF based on the system model and equipment information. In this embodiment 1, the control content includes the amount of power cutoff for the generator 2, load 3 and renewable energy source 4 by the power cutoff device or load cutoff device, and the active power and reactive power of the renewable energy source 4, storage battery 5 and voltage control equipment 6.

[0064] In step S6, the control content calculation unit 15 discretizes the control quantity as necessary.

[0065] In step S7, the communication unit 11 transmits the control content, including the discretized control quantity and the controlled object as needed, to the equipment determined to be the controlled object. As a result, the equipment determined to be the controlled object performs control based on the control quantity. After that, the operation shown in Figure 4 is completed.

[0066] <Summary of Embodiment 1> According to the grid stabilization system 8 of this embodiment 1 described above, when it is determined that an overload or abnormal voltage has occurred based on the grid model, the control content, including the controlled object and the controlled amount, is calculated by optimal power flow calculation based on the grid model and equipment information. The control content includes the interruption amount (interruption rate) of the generator 2 and the load 3. With this configuration, it is possible to appropriately determine the generator 2 and the load 3 to be controlled, and their interruption amount (interruption rate), while reducing the controlled amount and reducing voltage and power flow violations.

[0067] Furthermore, in this embodiment 1, the control content further includes at least one of the following: the amount of interruption (interruption rate) of the renewable energy power source 4, and the active power and reactive power of the renewable energy power source 4, the storage battery 5, and the voltage control equipment 6. With this configuration, it is possible to appropriately determine the amount of interruption (interruption rate) of the renewable energy power source 4 while reducing the amount of control, as well as the amount of voltage violations and power flow violations.

[0068] <Embodiment 2> Figure 5 is a block diagram showing the configuration of the system stabilization system 8 according to this second embodiment. The configuration in Figure 5 is the same as the configuration in Figure 2, with the addition of a sensitivity calculation unit 16.

[0069] The sensitivity calculation unit 16 calculates the sensitivity of at least one of the power flow in the power transmission lines of the power system and the voltage of the power busbars of the power system, based on the control content calculated by the control content calculation unit 15. For example, the sensitivity calculation unit 16 calculates the sensitivity to the control quantity of the controlled object included in the control content, or the sensitivity to the control quantity of the controlled object node included in the control content, by numerical analysis simulation.

[0070] In the following example, the active power (P) of the generator (i) is calculated in the first calculation example. (i) G ) and reactive power (Q (i) G The first example of calculating sensitivity to ) is explained, and in the second example, the active power (P) of the node (i) to be controlled is explained. (i) ) and reactive power (Q (i) This section explains an example of calculating sensitivity to the following. Note that even if the controlled object is not a generator but other equipment such as load 3 or renewable energy source 4, the sensitivity can be calculated in the same manner as below.

[0071] <First calculation example> The sensitivity calculation unit 16 performs power flow calculations, which are system calculations, by changing the operating state (output state) of one controlled object in a system model where an overload or abnormal voltage has been determined to occur. For example, if the controlled object of the control content is a generator (i) and the controlled amount of the control content is an active power (P) of 100 MW (i) G If this is the case, the sensitivity calculation unit 16 calculates the active power (P (i) G ) may be changed to 10MW or 100MW. Unlike OPF, in power flow calculations, the power generated by generator 2 and the power consumed by load 3 are fixed values, and the power flow through the transmission lines, etc., as well as the voltage and phase of each part, are calculated based on these fixed values.

[0072] The sensitivity calculation unit 16 calculates the change in power flow in the transmission line where overload occurs and the change in voltage of the busbar where abnormal voltage occurs by performing the above power flow calculation in the simulation. For example, if the change in the active power of generator (i) is ΔP (i) G When this is the case, ΔP is defined as the change in the active power flow, reactive power flow, and apparent power flow of the transmission line (k). (k) f , ΔQ (k) f ΔS (k) f This is calculated, and ΔV is expressed as the voltage change of the busbar (j). (j) Assume that the following is calculated. In this case, the sensitivity calculation unit 16 calculates ΔP using the following equation (5). (i) G ΔP for (k) f , ΔQ (k) f ΔS (k) f , ΔV (j) Calculate the sensitivity.

[0073]

number

[0074] For example, if the change in the active power of generator (i) is ΔQ (i) G When this is the case, ΔP is defined as the change in the active power flow, reactive power flow, and apparent power flow of the transmission line (k). (k) f , ΔQ (k) f ΔS (k) f This is calculated, and ΔV is expressed as the voltage change of the busbar (j). (j) Assume that the following is calculated. In this case, the sensitivity calculation unit 16 calculates ΔQ using the following equation (6). (i) G ΔP for (k) f , ΔQ (k) f ΔS (k) f , ΔV (j) Calculate the sensitivity.

[0075]

number

[0076] The sensitivity calculation unit 16 calculates the sensitivity for each controlled object, each transmission line where an overload occurs, and each busbar where an abnormal voltage occurs. The sensitivity calculation unit 16 may perform the sensitivity calculation multiple times for each controlled object and each transmission line or busbar. For example, the sensitivity calculation unit 16 may perform the sensitivity calculation multiple times while adjusting the degree of change in the operating state of the equipment in the simulation, and obtain the average or median of the multiple sensitivities obtained from the multiple calculations as the final sensitivity. Specifically, the controlled object of the control content is a generator (i), and the controlled amount of the control content is an active power (P) of 100 MW. (i) G If this is the case, the sensitivity calculation unit 16 calculates the active power (P (i) G The sensitivity is calculated by varying the value from -200MW to 200MW in 50MW increments, and then calculating nine different sensitivities. The sensitivity calculation unit 16 may then determine the average value of the nine sensitivities as the final sensitivity.

[0077] <Second calculation example> The sensitivity calculation unit 16 calculates the active power (P) flowing into the node (i) to be controlled. (i) ) and reactive power (Q (i) A voltage sensitivity matrix is ​​calculated that shows the change in the voltage at node (i) in response to a change in ). For example, the sensitivity calculation unit 16 calculates the voltage sensitivity matrix by calculating the partial derivative of the power flow equation. The power flow equation is an equation that shows the relationship between the active power and reactive power flowing into the node and the voltage at the node, and is expressed as shown in equation (7) below.

[0078]

number

[0079] P (i) and Q (i) These are the active power and reactive power flowing into node (i), respectively. V^· (i) (^· means that a dot is placed above the preceding character) is the voltage at node (i), V (i) exp(jV (i) It is represented as Y^· ik This is the node admittance matrix.

[0080] Equation (7), which represents the tidal equation, is given by V for the real part and imaginary part, respectively. (i) and δ (i) Taking the partial derivative with respect to this, we obtain equation (8).

[0081]

number

[0082] Equation (8) shows the change in voltage at node (i) (ΔV (i) ,Δδ (i) The change in active and reactive power (ΔP) of node (i) in relation to ) (i) ,ΔQ (i) ) represents the matrix J, which is called the Jacobian matrix of the tidal equation. Equation (8) shows the inverse matrix J of matrix J. -1 Multiplying by from the left, we obtain equation (9).

[0083]

number

[0084] Equation (9) shows the change in active and reactive power (ΔP) at node (i). (i) ,ΔQ (i) The change in voltage at node (i) (ΔV) (i) ,Δδ (i) This represents the inverse matrix J of the Jacobian matrix. -1 This is the voltage sensitivity matrix. For example, if the node to be controlled is node (i) and the node where an abnormal voltage occurs is node (j), then the change in active and reactive power (ΔP) of node (i) is... (i) ,ΔQ (i) The change in voltage at node (j) (ΔV) (j) ) can be expressed as shown in equation (10).

[0085]

number

[0086] The sensitivity calculation unit 16 calculates the voltage sensitivity matrix (J -1 In addition to calculating the power flow rate (P), the system also calculates a power flow sensitivity matrix that represents the changes in active and reactive power flow rates in the transmission line in response to changes in node voltage. For example, in a model like the one in Figure 6, the active power flow rate (P) on the node (i) side flowing through the transmission line (k) is calculated. (k) f ) and reactive power flow (Q (k) f ) and the voltage (V^·) of node (i) (i) ) and the voltage (V^·) at node (j) (j) The following relationship (11) holds between ) and ).

[0087]

number

[0088] y^· k This is the admittance of the transmission line (k). Equation (11) is given by V for the real and imaginary parts, respectively. (i) , δ (i) , V (j) and δ (j) Taking the partial derivative with respect to this, we obtain equation (12).

[0089]

number

[0090] Equation (12) shows the change in voltage at node (i) (ΔV (i) ,Δδ (i) Changes in active and reactive power flow (ΔP) of the transmission line (k) relative to ) (k) f ,ΔQ (k) f This represents the current sensitivity matrix.

[0091] Substituting equation (9) into equation (12), we get the change in active and reactive power (ΔP) at node (i). (i) ,ΔQ (i) Changes in active and reactive power flow (ΔP) of the transmission line (k) relative to ) (k) f ,ΔQ (k) f The following equation (13) is obtained, which represents ).

[0092]

number

[0093] The sensitivity calculation unit 16 calculates the voltage sensitivity matrix (J -1 The sensitivity is calculated using equation (13), which combines the power flow sensitivity matrix (P). For example, if the node to be controlled is node (i) and the transmission line where the overload occurs is transmission line (k), the change in active and reactive power (ΔP) of node (i) is calculated using equation (13). (i) ,ΔQ (i) Changes in active and reactive power flow (ΔP) of the transmission line (k) relative to ) (k) f ,ΔQ (k) f ) can be expressed as shown in equations (14) and (15).

[0094]

number

[0095]

number

[0096] <Summary of Embodiment 2> The grid stabilization system 8 may control not only the facilities of the general transmission and distribution operators (power companies) that operate the grid stabilization system 8, but also the facilities of power generators and general consumers. When controlling the facilities of power generators and general consumers, the operator of the grid stabilization system 8 may have to explain the appropriateness of the control content to the power generators and consumers.

[0097] Therefore, in the grid stabilization system 8 according to this embodiment 2, the sensitivity of at least one of the power flow in the power transmission lines of the power system and the voltage of the power busbars of the power system is calculated based on the control content. With this configuration, for example, the operator of the grid stabilization system 8 can explain the effectiveness and appropriateness of the control content in resolving overload and abnormal voltage by referring to the calculated sensitivity.

[0098] Furthermore, the sensitivity calculation unit 16 may also calculate sensitivity for equipment other than those mentioned above, such as transmission lines and busbars. In this case, for example, the operator of the grid stabilization system 8 can use the calculated sensitivity as a reference to explain why the equipment in question was not included in the control target for resolving overload and abnormal voltage. In addition, the grid stabilization system 8 may use AI (Artificial Intelligence) to machine learn (train) an explanation of the validity of the control content based on the calculated sensitivity, so that it can present such an explanation to the operator of the grid stabilization system 8.

[0099] <Embodiment 3> Figure 7 is a block diagram showing the configuration of the system stabilization system 8 according to this third embodiment. The configuration in Figure 7 is the same as the configuration in Figure 2, with the addition of a coefficient setting unit 17.

[0100] In this embodiment 3, the first to fourth configurations described below make it possible to suppress the concentration of control on a specific piece of equipment among the controlled objects, or to make a specific piece of equipment among the controlled objects more difficult or easier to control. Note that this embodiment 3 only needs to include at least one of the first to fourth configurations.

[0101] <First configuration> In the first configuration, the coefficient setting unit 17 sets weight coefficients to adjust the control values, which are at least one of the control quantities and control counts for each of the multiple controlled objects, and the control content calculation unit 15 uses the objective function including the set weight coefficients in the OPF. For example, the coefficient setting unit 17 sets weight coefficients W to adjust the control values ​​of the generator 2, load 3, and renewable energy source 4. i PG ,W i PL ,W i PRES Set the weight coefficient W in the following explanation. i PG ,W i PL ,W i PRES If they are not distinguished, they are referred to as weight coefficients W. The control content calculation unit 15 uses equation (2) and weight coefficients W. i PG ,W i PL ,W i PRES The objective function used in the OPF is expressed by equation (16) below, which includes the following.

[0102]

number

[0103] For example, the weight coefficient W in equation (16) i PG The larger the value of the generator (i), the smaller the control value of the generator (i), and the less likely the generator (i) is to be controlled. Conversely, the weighting coefficient W in equation (16) i PG The smaller the value, the larger the control value of generator (i), and the easier it becomes for generator (i) to be controlled.

[0104] Therefore, the coefficient setting unit 17 sets the weight coefficient W of the controlled object to a large value so that the larger the past controlled value of the controlled object, the smaller the controlled value of the controlled object becomes. On the other hand, the coefficient setting unit 17 sets the weight coefficient W of the controlled object to a small value so that the smaller the past controlled value of the controlled object, the larger the controlled value of the controlled object becomes.

[0105] This first configuration makes it possible to suppress the concentration of control on specific equipment among the controlled objects, thereby making the control of the controlled objects fairer (uniform).

[0106] Furthermore, the objective function including the weight coefficients set by the control content calculation unit 15 is not limited to equation (16), but may also include, for example, an objective function including equation (3) and the weight coefficients. In addition, the coefficient setting unit 17 may set the weight coefficients determined by trial and error by the operator of the system stabilization system 8, or it may set the weight coefficients calculated by the following equations (17) and (18), or it may set weight coefficients other than these.

[0107]

number

[0108]

number

[0109] P i Gtotal This is the cumulative control amount in the operation of generator (i) to date, and a G ,b G ,c G These are the parameters used in calculating the weight coefficients.

[0110] <Second configuration> In the second configuration, similar to the first configuration, the coefficient setting unit 17 sets weight coefficients W to adjust the control values ​​of each of the multiple controlled objects, and the control content calculation unit 15 uses the objective function including the set weight coefficients W in the OPF. However, the coefficient setting unit 17 sets the weight coefficients W of the controlled objects in such a way that predetermined equipment is less likely to be selected as a controlled object or is more likely to be selected, or that the control value becomes smaller or larger when selected.

[0111] For example, if equipment is designated as equipment for which continued operation or stable power supply is desirable, the coefficient setting unit 17 sets the weighting coefficient W of the controlled equipment to a large value so that the equipment is less likely to be selected as a controlled equipment and the controlled value is smaller than that of other equipment. Equipment for which continued operation or stable power supply is desirable is, for example, a hospital or a mass transformer power supply necessary for stabilizing the power system.

[0112] On the other hand, if equipment is designated in advance as equipment that is preferable to be controlled, the coefficient setting unit 17 sets the weighting coefficient W of the equipment to be controlled to a small value so that the equipment is more likely to be selected as the equipment to be controlled and the control value is larger than that of other equipment. Equipment that is preferable to be controlled is, for example, a power plant that recovers quickly even after stopping, or the cost required for recovery is low.

[0113] This second configuration makes it possible to make certain pieces of equipment among those being controlled more difficult or easier to control.

[0114] <Third configuration> In the third configuration, the control content calculation unit 15 generates an objective function to minimize the variation in the controlled quantities of multiple controlled objects and uses it in the OPF. For example, when the control content calculation unit 15 performs OPF using a certain objective function, it performs OPF using an objective function that minimizes the variation in the controlled quantities of multiple controlled objects. The objective function that minimizes the variation in the controlled quantities of multiple controlled objects can be expressed, for example, as shown in equation (19) below.

[0115]

number

[0116] Note: K G3 ,K L3 ,K RES3 σ is the weighting coefficient of the objective function. This weighting coefficient may be constant or may be changed based on the history of the controlled variables of multiple controlled objects. 2 PG ,σ 2 PL ,σ 2 PRES This represents the variability in the amount of interruption for generator 2, load 3, and renewable energy source 4. The variability in the amount of interruption for generator 2 can be expressed, for example, as shown in equation (20), and the variability in the amount of interruption for load 3 and renewable energy source 4 can be expressed similarly.

[0117]

number

[0118] In the above explanation, the variation in the controlled quantity across multiple controlled objects was the variation in the interruption amounts of generator 2, load 3, and renewable energy source 4. However, it is not limited to this, and could be, for example, the variation in the interruption amount of generator 2, load 3, and renewable energy source 4 as a whole. Also, in the above explanation, the variation in the controlled quantity was the variance of the controlled quantity, but it is not limited to this, and could be, for example, the standard deviation, mean deviation, or the difference between the maximum and minimum values ​​of the controlled quantity.

[0119] This third configuration makes it possible to suppress the concentration of control on specific equipment among the controlled objects, thereby making the control of the controlled objects fairer (more uniform).

[0120] <4th configuration> In the fourth configuration, the control content calculation unit 15 adjusts the control quantities of multiple controlled objects based on the history of the control quantities of multiple controlled objects when the control effects of multiple controlled objects correspond to each other. The correspondence of the control effects of multiple controlled objects includes, for example, at least one of the following: the electrical distance between the multiple controlled objects is below a threshold, and the difference between the power flow change and voltage change of the multiple controlled objects is below a threshold.

[0121] For example, if the control effect of the first controlled object corresponds to the control effect of the second controlled object, the control content calculation unit 15 may determine from the history of the control quantities whether the total value of the control quantities of the first controlled object up to now is greater than the first threshold, and whether the total value of the control quantities of the second controlled object up to now is less than the second threshold, which is less than the first threshold. If the control content calculation unit 15 determines that the total value of the first controlled object is greater than the first threshold and the total value of the second controlled object is less than the second threshold, it may replace the current control quantity of the first controlled object with the current control quantity of the second controlled object. Alternatively, the control content calculation unit 15 may set the average value of the control quantity of the first controlled object and the control quantity of the second controlled object obtained in the current OPF as the control quantities of the first and second controlled objects.

[0122] For example, if the control effect of the first controlled object corresponds to the control effect of the second controlled object, the control content calculation unit 15 may, according to the rotation table, replace the control amount of the first controlled object obtained in this OPF with the control amount of the second controlled object obtained in this OPF.

[0123] This fourth configuration makes it possible to suppress the concentration of control on specific equipment among the controlled objects, thereby making the control of the controlled objects fairer (more uniform).

[0124] <Operation> Figure 8 is a flowchart showing the operation of the system stabilization system 8 according to this third embodiment. The operation in Figure 8 is similar to the operation in Figure 4, but with step S11 added and steps S5 and S6 of the operation in Figure 4 changed to steps S5a and S6a. Therefore, the following will mainly describe steps S11, S5a, and S6a.

[0125] If it is determined in step S4 that an overload or abnormal voltage has occurred, the process proceeds to step S11. In step S11, the coefficient setting unit 17 sets the weight coefficients described in the first and second configurations. After that, the process proceeds to step S5a.

[0126] In step S5a, the control content calculation unit 15 calculates the control content, including the controlled object and the controlled quantity of the controlled object, using the OPF based on the system model and equipment information. The objective function used in the OPF includes, for example, at least one of the objective functions described in the first to third configurations.

[0127] In step S6a, the control content calculation unit 15 adjusts the control quantity as described in the fourth configuration or discretizes the control quantity, if necessary.

[0128] <Summary of Embodiment 3> As described above, the system stabilization system 8 according to this embodiment 3 can suppress the concentration of control on specific equipment among the controlled items, make it difficult or easy to control specific equipment among the controlled items, through the first to fourth configurations. Therefore, the controlled items can be controlled appropriately.

[0129] <Embodiment 4> Figure 9 is a schematic diagram showing a power system using the grid stabilization system 8 according to this embodiment 4. The grid stabilization system 8 in Figure 9 comprises a central computing unit 8a and one or more slave station devices 8b that can communicate with the central computing unit 8a. The power system in Figure 9 is the same as the power system in Figure 1, except for this point.

[0130] The central processing unit 8a acquires measurement information of the power system from the measurement device 7 via the slave station device 8b and generates a control table that associates predetermined fault patterns with control contents. Based on the measurement information, the slave station device 8b determines that a fault pattern from the control table has occurred in the power system, and then determines the control contents associated with that fault pattern in the control table. The slave station device 8b then transmits (commands) the control contents to the equipment to be controlled, thereby resolving the system abnormality state that occurs after the fault has been cleared.

[0131] <Central processing unit 8a> Figure 10 is a block diagram showing the configuration of the central processing unit 8a. The central processing unit 8a in Figure 10 includes a first acquisition unit, which is a communication unit 21, a recording unit 22, a hypothetical accident setting unit 23, a model generation unit 24, and a control content calculation unit 25.

[0132] The communication unit 21 receives and acquires power system measurement information from the measuring device 7 sequentially (for example, periodically) via the slave station device 8b. The communication unit 21 also transmits the control table generated by the central processing unit 8a to the slave station device 8b as appropriate.

[0133] The recording unit 22 records the measurement information collected by the communication unit 21, the equipment information of the power system, the calculation results of the control content calculation unit 25, and the equipment's past control history (for example, the history of the controlled quantity).

[0134] The assumed fault setting unit 23 sets up multiple fault patterns that may occur in the current power system based on measurement information and equipment information. These fault patterns include, for example, a predetermined first transmission line experiencing a ground fault or short circuit due to a lightning strike, fallen tree, or contact with a flying object, and a predetermined second transmission line being opened to mitigate the effects of the ground fault or short circuit on the first transmission line. Note that the multiple fault patterns do not necessarily have to be predetermined by the assumed fault setting unit 23; they may also be predetermined by the operator of the system stabilization system 8.

[0135] The model generation unit 24 generates a system model for each of the multiple accident patterns based on measurement information, equipment information, and a predetermined set of accident patterns. The generation of system models by the model generation unit 24 is the same as the generation of system models by the model generation unit 14 in Figure 2. In the system models generated by the model generation unit 24, for example, the parts of the connection relationships between equipment that are disconnected differ depending on the accident pattern.

[0136] The control content calculation unit 25 determines whether an overload or abnormal voltage occurs based on the fault pattern system model, similar to the control content calculation unit 15 described in Embodiment 1. If the control content calculation unit 25 determines that an overload or abnormal voltage occurs, it calculates the control content using the OPF based on the system model and equipment information, similar to the control content calculation unit 15 described in Embodiment 1. The control content only needs to include the interruption amount, which is the control quantity of at least one of the controlled generator 2 and load 3, and may also include the interruption amount, which is the control quantity of the controlled renewable energy power source 4, similar to Embodiment 1.

[0137] The control content calculation unit 25 generates a control table that associates accident patterns with the control content calculated from those accident patterns. If the control content calculation unit 25 calculates multiple control content from multiple accident patterns, the multiple accident patterns and multiple control content are associated in the control table.

[0138] The components of the central processing unit 8a are not limited to those described above. For example, the central processing unit 8a may further include the sensitivity calculation unit 16 described in Embodiment 2, or the coefficient setting unit 17 described in Embodiment 3.

[0139] <Slave station device 8b> Figure 11 is a block diagram showing the configuration of the slave unit 8b. The slave unit 8b in Figure 11 comprises a second acquisition unit, which is a communication unit 31, a recording unit 32, an accident occurrence determination unit 33, and a control content determination unit 34.

[0140] The communication unit 31 receives and acquires measurement information of the power system sequentially (for example, periodically) from the measuring device 7 and transmits the measurement information to the central processing unit 8a as appropriate. The communication unit 31 also receives and acquires control tables from the central processing unit 8a and transmits (commands) the control content determined by the control content determination unit 34 to the equipment to be controlled.

[0141] The recording unit 32 records equipment information of the power system under the jurisdiction of the slave station device 8b, as well as measurement information and control tables acquired by the communication unit 31.

[0142] The fault occurrence determination unit 33, similar to the fault occurrence determination unit 13 in Figure 2, determines whether or not a fault pattern from the control table has occurred in the power system based on the measurement information. In this embodiment 4, the fault pattern corresponds to the operating state of the protective relay or an overload or abnormal voltage in the power system.

[0143] The control content determination unit 34 determines the control content associated with the accident pattern that has been determined to have occurred, as determined by the control table.

[0144] <Operation> Figure 12 is a flowchart showing the operation of the central processing unit 8a according to this embodiment 4.

[0145] In step S21, the communication unit 21 sequentially receives and acquires power system measurement information from the measuring device 7 via the slave station device 8b.

[0146] In step S22, the assumed fault setting unit 23 or the operator sets multiple fault patterns that could occur in the current power grid.

[0147] In step S23, the model generation unit 24 generates a system model for each of the multiple accident patterns based on the measurement information, equipment information, and multiple accident patterns.

[0148] In step S24, the control content calculation unit 25 determines whether an overload or abnormal voltage occurs based on a system model of one fault pattern. If it is determined that an overload or abnormal voltage will occur, the process proceeds to step S25; otherwise, the process proceeds to step S26.

[0149] In step S25, the control content calculation unit 25 calculates one control content using the OPF based on the system model and equipment information of one fault pattern, and associates one fault pattern with one control content in the control table. The control content determination unit 25 may discretize the control quantities included in the control content as needed, similar to the control content calculation unit 15 in Figure 2.

[0150] In step S26, the control content calculation unit 25 determines whether the determination in step S24 has been made for all of the multiple accident patterns. If the determination in step S24 has been made for all of the multiple accident patterns, the process proceeds to step S27. If the determination in step S24 has not been made for all of the multiple accident patterns, the process proceeds to step S24.

[0151] In step S27, the communication unit 21 transmits the control table to the slave station device 8b. After that, the operation shown in Figure 12 is completed.

[0152] Figure 13 is a flowchart illustrating the operation of the slave unit 8b according to this embodiment 4. It is assumed that the slave unit 8b has already received the control table from the central processing unit 8a before performing this operation.

[0153] In step S31, the communication unit 31 sequentially receives and acquires measurement information of the power system from the measuring device 7, and transmits the measurement information to the central processing unit 8a as appropriate.

[0154] In step S32, the fault occurrence determination unit 33 determines, based on the measurement information, whether or not a fault pattern from the control table has occurred in the power system. If it is determined that a fault pattern has occurred in the power system, the process proceeds to step S33; otherwise, the process proceeds to step S31.

[0155] In step S33, the control content determination unit 34 determines the control content associated with the accident pattern determined to have occurred in the control table. The control content determination unit 34 may, if necessary, discretize the control quantities included in the control content, similar to the control content calculation unit 15 in Figure 2.

[0156] In step S34, the communication unit 31 transmits the control content to the equipment determined to be controlled. As a result, the equipment determined to be controlled performs control based on the control quantity. After that, the operation shown in Figure 13 is completed.

[0157] <Summary of Embodiment 4> According to the power grid stabilization system 8 of this embodiment 4 described above, the central processing unit 8a can create a control table including control details before a fault occurs in the power grid and transmit the control table to the slave station 8b. Then, when a fault occurs in the power grid, the slave station 8b can determine the control details without communicating with the central processing unit 8a.

[0158] This reduces the processing load on the central processing unit 8a after an accident, and also allows for rapid transmission of control information from the slave unit 8b to the controlled object. Therefore, it eliminates the need for a high-performance computer and a wide-area, high-speed communication network. In order to transmit control information from the slave unit 8b to the controlled object more quickly, it is preferable that the electrical distance between the slave unit 8b and the controlled object is smaller than the electrical distance between the central processing unit 8a and the controlled object.

[0159] <Other variations> The communication unit 11, accident occurrence determination unit 13, model generation unit 14, and control content calculation unit 15 shown in FIG. 2 above are hereinafter referred to as "communication unit 11 etc.". The communication unit 11 etc. are realized by the processing circuit 81 shown in FIG. 14. That is, the processing circuit 81 includes a communication unit 11 that acquires measurement information of the power system, an accident occurrence determination unit 13 that determines whether an accident has occurred in the power system based on the measurement information, and a model generation unit 14 that generates a system model based on the measurement information and the equipment information of the power system when it is determined that an accident has occurred. When it is determined that an overload or abnormal voltage has occurred based on the system model, a control content calculation unit 15 that calculates, by optimal power flow calculation, control content including a control target and a control amount of the control target based on the system model and the equipment information. The control content includes a cutoff amount that is a control amount of at least one of the generators and loads that are the control targets. For the processing circuit 81, dedicated hardware may be applied, or a processor that executes a program stored in a memory may be applied. Examples of the processor include a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a DSP (Digital Signal Processor).

[0160] When the processing circuit 81 is dedicated hardware, the processing circuit 81 corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The functions of each part such as the communication unit 11 etc. may be realized by a circuit in which the processing circuit is distributed, or the functions of each part may be realized by one processing circuit collectively.

[0161] When the processing circuit 81 is a processor, functions such as the communication unit 11 are realized in combination with software or the like. Note that the software or the like includes, for example, software, firmware, or software and firmware. The software or the like is described as a program and stored in a memory. As shown in FIG. 15, the processor 82 applied to the processing circuit 81 reads and executes the program stored in the memory 83 to realize the functions of each part. That is, when the power grid stabilization system 8 is executed by the processing circuit 81, it includes steps of acquiring measurement information of the power grid, determining whether an accident has occurred in the power grid based on the measurement information, generating a grid model based on the measurement information and the equipment information of the power grid when it is determined that an accident has occurred, and calculating, by optimal power flow calculation, control content including a control target and a control amount of the control target based on the grid model and the equipment information when it is determined that an overload or an abnormal voltage has occurred based on the grid model. The memory 83 is provided for storing a program that will ultimately be executed. In other words, this program can be said to cause a computer to execute procedures and methods such as those of the communication unit 11. Here, the memory 83 may be, for example, a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), HDD (Hard Disk Drive), magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disc), their drive devices, or any storage medium to be used in the future.

[0162] The above describes a configuration in which each function of the communication unit 11, etc., is realized by either hardware or software. However, this is not the only configuration; a configuration in which part of the communication unit 11, etc., is realized by dedicated hardware and another part by software, etc., is also possible. For example, the function of the communication unit 11 can be realized by a processing circuit 81 as dedicated hardware, while the functions of the others can be realized by a processing circuit 81 as a processor 82 reading and executing a program stored in memory 83.

[0163] As described above, the processing circuit 81 can realize each of the above-mentioned functions by hardware, software, or a combination thereof. The components of the grid stabilization system 8 in Figure 5, the components of the grid stabilization system 8 in Figure 7, the components of the central processing unit 8a in Figure 10, and the components of the slave station device 8b in Figure 11 are the same as described above.

[0164] Furthermore, it is possible to freely combine each embodiment and each variation, and to modify or omit each embodiment and each variation as appropriate.

[0165] The above explanation is illustrative and not limiting in all respects. It should be understood that countless variations not illustrated are conceivable. [Explanation of symbols]

[0166] 2 Generator, 3 Load, 4 Renewable energy source, 5 Storage battery, 6 Voltage control equipment, 8 System stabilization system, 8a Central processing unit, 8b Substation equipment, 11,21,31 Communication unit, 13,33 Accident occurrence determination unit, 14,24 Model generation unit, 15,25 Control content calculation unit, 16 Sensitivity calculation unit, 17 Coefficient setting unit, 34 Control content determination unit.< / opf>

Claims

1. An acquisition unit that acquires measurement information of the power system including the generator and load, An accident occurrence determination unit that determines whether or not an accident has occurred in the power system based on the measurement information, When it is determined that the aforementioned accident has occurred, a model generation unit generates a system model based on the measurement information and the power system equipment information, If it is determined that an overload or abnormal voltage occurs based on the system model, a control content calculation unit calculates a control content including the controlled object and the controlled amount of the controlled object based on the system model and the equipment information, by performing an optimal power flow calculation with the controlled amount of the controlled object as a variable. Equipped with, The control content includes a cutoff amount which is the control amount of at least one of the generator and the load that are the targets of control. A power system stabilization system further comprising a sensitivity calculation unit that calculates the sensitivity of at least one of the power flow in the power transmission lines of the power system and the voltage of the busbars of the power system based on the control content described above.

2. A system stabilization system according to claim 1, The aforementioned power system further includes a renewable energy source, a storage battery, and voltage control equipment. The aforementioned control contents are: The control amount of the renewable energy power source that is the target of control is the interruption amount, The active power and reactive power are the control quantities of the renewable energy power source, the storage battery and the voltage control device that are the objects of control. A system stabilization system further comprising at least one of the following.

3. A system stabilization system according to claim 1, The aforementioned sensitivity calculation unit, A grid stabilization system that calculates the sensitivity by changing the operating state of the controlled object and performing grid calculations.

4. A system stabilization system according to claim 1, The aforementioned sensitivity calculation unit, A grid stabilization system that calculates the sensitivity using a voltage sensitivity matrix, which is the inverse of the Jacobian matrix of the power flow equation and represents the change in the voltage of the node to be controlled in response to changes in the active power and reactive power of the node, and a power flow sensitivity matrix, which represents the change in the active power flow and reactive power flow of the transmission line in response to changes in the voltage of the node.

5. A system stabilization system according to claim 1, The system stabilization system includes a sensitivity calculation unit that presents the sensitivity calculated by the sensitivity calculation unit together with the control content derived by the control content calculation unit.

6. A system stabilization system according to claim 1 or claim 2, The control content calculation unit is: A power grid stabilization system that uses an objective function in the optimal power flow calculation to minimize the variation in the controlled quantities of multiple controlled objects.

7. A system stabilization system according to claim 1 or claim 2, The control content calculation unit is: A system stabilization system that adjusts the control amounts of multiple controlled objects based on the history of the control amounts of the multiple controlled objects when the control effects of the multiple controlled objects correspond to each other.

8. A system stabilization system according to claim 1 or claim 2, The system further includes a coefficient setting unit that sets a weighting coefficient for adjusting a control value which is at least one of the control amount and control count for each of the multiple control targets, The control content calculation unit is a power grid stabilization system that uses the objective function including the weight coefficients in the optimal power flow calculation.

9. A system stabilization system according to claim 8, The coefficient setting unit is, A system stabilization system that sets the weight coefficient such that the larger the past control value of the controlled object, the smaller the control value of the controlled object becomes, or the smaller the past control value of the controlled object, the larger the control value of the controlled object becomes.

10. A system stabilization system according to claim 8, The coefficient setting unit is, A system stabilization system that sets the weighting coefficient so that the control value of the controlled object becomes larger or smaller when the controlled object is a predetermined piece of equipment.

11. The central processing unit and The aforementioned central processing unit and a slave station device capable of communicating with it Equipped with, The aforementioned central processing unit is A first acquisition unit that acquires measurement information of the power system including the generator and load, A model generation unit generates a system model for each of the predetermined fault patterns based on the measurement information, the equipment information of the power system, and a predetermined set of fault patterns. When it is determined that an overload or abnormal voltage occurs based on the system model of the fault pattern, a control content calculation unit calculates control content including the controlled object and the controlled amount of the controlled object based on the system model and the equipment information by optimal power flow calculation with the controlled amount of the controlled object as a variable, and generates a control table that associates the fault pattern with the control content. Includes, The control content includes a cutoff amount which is the control amount of at least one of the generator and the load that are the targets of control. The aforementioned substation device is, A second acquisition unit that acquires the aforementioned measurement information and the aforementioned control table, Based on the measurement information, the power system includes an accident occurrence determination unit that determines whether or not the accident pattern of the control table has occurred, A control content determination unit determines the control content associated with the accident pattern that has been determined to have occurred and the control table. Includes, The aforementioned central processing unit is A power system stabilization system further comprising a sensitivity calculation unit that calculates the sensitivity of at least one of the power flow in the power transmission lines of the power system and the voltage of the busbars of the power system based on the control content described above.

12. We acquire measurement information of the power system, including generators and loads. Based on the measurement information, it is determined whether or not an accident has occurred in the power system. If it is determined that the aforementioned accident has occurred, a system model is generated based on the measurement information and the power system equipment information. If it is determined that an overload or abnormal voltage occurs based on the system model, the control content, including the controlled object and the controlled amount of the controlled object, is calculated based on the system model and the equipment information by an optimal power flow calculation with the controlled amount of the controlled object as a variable. The control content includes a cutoff amount which is the control amount of at least one of the generator and the load that are the targets of control. A power system stabilization method for calculating the sensitivity of at least one of the power flow in the power transmission lines of the power system and the voltage of the busbars of the power system, based on the control content described above.

13. A method for stabilizing a power system stabilization system, The system stabilization system comprises a central computing unit and a slave unit capable of communicating with the central computing unit. The aforementioned central processing unit is We acquire measurement information of the power system, including generators and loads. Based on the measurement information, the power system equipment information, and a predetermined set of fault patterns, a system model is generated for each of the set of fault patterns. If it is determined that an overload or abnormal voltage occurs based on the system model of the fault pattern, the control content, including the controlled object and the controlled quantity of the controlled object, is calculated based on the system model and the equipment information by an optimal power flow calculation with the controlled quantity of the controlled object as a variable, and a control table is generated that associates the fault pattern with the control content. The control content includes a cutoff amount which is the control amount of at least one of the generator and the load that are the targets of control. The aforementioned substation device is, The measurement information and the control table are acquired. Based on the measurement information, it is determined whether the fault pattern in the control table occurred in the power system. The control content is determined to correspond to the accident pattern that was determined to have occurred in the control table. The aforementioned central processing unit is A power system stabilization method for calculating the sensitivity of at least one of the power flow in the power transmission lines of the power system and the voltage of the busbars of the power system, based on the control content described above.

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