Power system control device and power system control method

Abstract

To provide a power system control device capable of suppressing an increase of an operation cost which is caused by a time change of the state of a power system.SOLUTION: A scenario creation unit 120 creates a scenario which indicates whether or not each of multiple control clock times is determined as a target clock time for operating an electric device 5 included in a power system 3, for each of combinations of two or more values that can be taken by the scenario. A control plan making unit 130 determines, for each of the scenarios, the operation content of the operation performed on the electric device 5 included in the power system 3 at each of the target clock times on the basis of system time change data. An effective-level calculation unit 140 calculates, for each of the scenarios, an effective level which indicates an evaluation of the effectiveness of the scenario on the basis of an operation cost regarding the operation performed on the electric device 5 and an index value which indicates an evaluation of the state of the power system 3. A control decision unit 160 decides a control scenario for use in controlling the power system 3 on the basis of the effective level.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a power system control device and a power system control method.

Background Art

[0002] A power system control device that controls a power system operates each facility of the power system so that a plurality of index values such as transmission loss, transmission capacity, and voltage stability are increased while satisfying the constraint conditions related to the power system according to the state of the power system such as power demand. However, this type of power system control device has a problem that the cost associated with the operation of the facilities (hereinafter referred to as the operation cost) may increase.

[0003] In contrast, Patent Document 1 discloses a technique for calculating the operation cost associated with the operation of the operation target facilities of the power system. In this technique, the operation amount for the operation target facilities is calculated so that the index value including the operation cost becomes a predetermined value while satisfying the constraint conditions related to the power system. Thereby, the operation cost can be suppressed while improving the voltage stability.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the state of the power system changes with time, depending on the time change, wasteful operations such as repeatedly performing an operation to change the operation target facilities to a certain state and an operation to return to the original state in a short time may be performed, and the operation cost may increase. In the technique described in Patent Document 1, since only the operation cost at a specific time is calculated, it is difficult to suppress the increase in the operation cost due to the time change of the state of the power system.

[0006] The purpose of this disclosure is to provide a power system control device and a power system control method that can suppress the increase in operating costs due to changes in the state of the power system over time. [Means for solving the problem]

[0007] A power system control device according to one aspect of the present disclosure generates a scenario for each of several future control times, indicating whether or not to make it a target time for performing operations on equipment to be operated included in the power system, for each of two or more possible values ​​of the scenario; determines the content of the operation on the equipment to be operated at each of the target times for each scenario based on the system time change data; calculates an effectiveness score for each scenario, evaluating the effectiveness of the scenario based on the operation cost related to the operation on the equipment to be operated in that scenario and an index value that evaluates the state of the power system in that scenario; and determines a control scenario from the scenarios that is to be used to control the power system based on the effectiveness score. [Effects of the Invention]

[0008] According to the present invention, it becomes possible to suppress the increase in operating costs due to changes in the state of the power grid over time. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows the configuration of a power system control device according to one embodiment of the present disclosure. [Figure 2] This is a diagram showing an example scenario. [Figure 3] This is a flowchart illustrating the overall processing of the power system control device 1. [Figure 4] This is a flowchart illustrating an example of the effectiveness calculation process. [Figure 5] This is a flowchart illustrating an example of a constraint satisfaction determination process. [Figure 6]This figure shows an example of the judgment process. [Figure 7] This figure shows another example of the judgment process. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described below with reference to the drawings.

[0011] Figure 1 is a diagram showing the configuration of a power system control device according to one embodiment of the present disclosure. The power system control device 1 shown in Figure 1 is a system that is communicatively connected to each component of a power system 3 via a communication network 2 and controls the power system 3 using each component. In the example of Figure 1, the power system 3 has measuring instruments 4 that measure physical quantities related to the power system 3, such as voltage and current, and electrical equipment 5 that are operated by the power system control device 1. There may be multiple measuring instruments 4 and electrical equipment 5. Examples of electrical equipment 5 include power generation equipment, reactive power adjustment devices such as SVCs (Static Var Compensators), transformers, power capacitors, and circuit breakers.

[0012] The power system control device 1 includes a control unit 10, a recording unit 20, an input unit 30, a display unit 40, and a communication unit 50.

[0013] The control unit 10 is a processor such as a CPU (Central Processing Unit), and is also called a processing unit. The control unit 10 reads a program (computer program: not shown) recorded in the recording unit 20 and executes the read program to realize various functions. In this embodiment, the control unit 10 realizes the main control unit 110, the scenario generation unit 120, the control planning unit 130, the effectiveness calculation unit 140, the constraint satisfaction determination unit 150, and the control decision unit 160 by executing the program.

[0014] The main control unit 110 controls the entire respective units of the control unit 10. The scenario generation unit 120 generates a plurality of scenarios indicating whether to apply an optimization calculation to the target equipment group for each of a plurality of control times within a future prediction period. In the present embodiment, the main control unit 110 generates scenarios for two or more combinations of whether to apply the optimization calculation. The optimization calculation is a process of determining the operation content for each electric device 5 at each application time so that a predetermined objective function is optimized, for example, so that the value of the objective function becomes a predetermined value (maximum value or minimum value). The objective function is, for example, the available transmission capacity that is the sum (or weighted sum) of the available transmission capacities for each transmission line. In this case, the predetermined value is the maximum value. However, the objective function is not limited to the available transmission capacity and may be, for example, the active power loss. In this case, the predetermined value is the minimum value. The prediction period is, for example, about 3 hours to 12 hours. Also, in the present embodiment, the interval between control times is constant, and the value thereof is, for example, about 5 minutes to 30 minutes. However, the prediction period and the interval between control times are not limited to these examples.

[0015] FIG. 2 is a diagram showing an example of a scenario. In FIG. 2, the control times are t0 to t3, and among scenarios 1 to n, the values at the control times t0 to t3 of scenarios 1 to 3 and n are schematically shown. In the example of FIG. 2, since the scenarios are generated for all combinations of possible values, n is 16. Note that the interval between the control times t0 to t3 is, for example, 30 minutes. In this case, the control time t0 is 30 minutes later, t1 is 1 hour later, t2 is 1.5 hours later, and t3 is 2 hours later.

[0016] For example, scenario 1 is a scenario in which an optimization calculation is performed at all control times t0 to t3. Scenario 2 is a scenario in which an optimization calculation is not performed at the first control time t0 and an optimization calculation is performed at the other control times t1 to t3. Scenario n is a scenario in which an optimization calculation is not performed at all control times t0 to t3.

[0017] Return to the description of FIG. 1. The control planning unit 130 performs optimization calculations for each scenario generated by the scenario generation unit 120, and for each scenario, generates operation information indicating the operation content for each electrical device 5 at each application time of the scenario. Note that the set of electrical devices 5 to be calculated in the optimization calculation may be the same as or different from the set of electrical devices 5 whose application / non-application is changed in the scenario.

[0018] The effectiveness calculation unit 140 calculates the effectiveness of evaluating the effectiveness of a scenario based on the operation cost related to the operation on the electrical device 5 in the scenario and the index value obtained by evaluating the state of the power system 3 in the scenario for each scenario generated by the scenario generation unit 120.

[0019] The constraint satisfaction determination unit 150 determines for each scenario generated by the scenario generation unit 120 whether the scenario satisfies the constraint conditions related to the power system 3. The constraint conditions are conditions for capacity constraints, voltage deviation degrees, voltage stability, etc. related to the power system 3.

[0020] The control decision unit 160 determines a control scenario, which is a scenario used for controlling the electrical devices 5 of the power system 3, from the scenarios generated by the scenario generation unit 120 based on the effectiveness calculated by the effectiveness calculation unit 140 and the determination result by the constraint satisfaction determination unit 150.

[0021] The main control unit 110 implements the control of the electrical devices 5 in accordance with the control scenario determined by the control decision unit 160. Instead of controlling for all times of the scenario, it may use only a part of the most recent time for control and perform recalculation for the non-controlled time to avoid the adverse effects caused by prediction errors.

[0022] The recording unit 20 is a memory that records the above-mentioned program and various information used and generated by the program's processing. In this embodiment, the recording unit 20 records system-related data 210, system measurement data 220, control schedule 230, scenario data 240, control data 250, cost data 260, index value data 270, effectiveness data 280, and constraint satisfaction data 290.

[0023] The grid-related data 210 is data relating to the power system 3, and includes power configuration data showing the configuration of the power system 3 (arrangement and configuration of each facility, impedance of the distribution network, etc.) and grid time change data predicting the time change of values ​​related to the state of the power system 3. Values ​​related to the state of the power system 3 include, for example, the output power of the generators of the power system 3 and the power demanded by consumers of the power system 3. The grid measurement data 220 is measurement data measured by the measuring instruments 4 of the power system 3. The control schedule 230 is information indicating the schedule for controlling the power system 3, for example, the prediction period and control time related to the optimization calculation. The control schedule 230 may be predetermined or specified by a user of the power system control device 1.

[0024] Scenario data 240 shows each scenario generated by the scenario generation unit 120. Control data 250 shows the operation information generated by the control planning unit 130 and the control scenario determined by the control decision unit 160. Cost data 260 shows the operation cost for each scenario. Indicator value data 270 shows the indicator value for each scenario. Effectiveness data 280 shows the effectiveness of each scenario calculated by the effectiveness calculation unit 140. Constraint satisfaction data 290 shows the determination result for each scenario by the constraint satisfaction determination unit 150.

[0025] The input unit 30 receives various information from users of the power system control device 1. For example, the input unit 30 may receive a control schedule 230 from the user. The display unit 40 displays various information. For example, the display unit 40 displays control data 250 and constraint satisfaction data 290. The communication unit 50 is connected to each measuring instrument 4 and electrical equipment 5 of the power system 3 via the communication network 2. For example, the communication unit 50 receives measurement data from the measuring instrument 4 and transmits command data corresponding to the control data 250 to the electrical equipment 5.

[0026] Figure 3 is a flowchart illustrating the overall processing of the power system control device 1.

[0027] First, the main control unit 110 acquires system time change data that predicts the time changes in the output power of the generators in the power system 3 and the demand power from consumers in the power system 3 (step S1). For example, the main control unit 110 may calculate the system time change data from system-related data 210 and system measurement data 220, or it may acquire the system time change data from a higher-level device (not shown). The system time change data may also be recorded in the recording unit 20.

[0028] Next, the scenario generation unit 120 generates scenarios for all possible combinations of values ​​based on the control schedule 230. For each scenario generated by the scenario generation unit 120, the control planning unit 130 performs optimization calculations based on the system time change data and generates operation information indicating the operation content for each electrical equipment 5 at the target time in each scenario (step S2).

[0029] Subsequently, the effectiveness calculation unit 140 performs an effectiveness calculation process (see Figure 4) to calculate the effectiveness of each scenario generated by the scenario generation unit 120 (step S3).

[0030] Furthermore, the constraint satisfaction determination unit 150 performs a constraint satisfaction determination process (see Figures 5 to 7) to determine whether or not the constraint conditions related to the power system 3 are satisfied for each scenario generated by the scenario generation unit 120 (step S4).

[0031] The control decision unit 160 determines whether the highest maximum effectiveness among the effective levels of each scenario is equal to or greater than the threshold, and whether the scenario with the highest effectiveness satisfies the constraint conditions (step S5).

[0032] If the maximum effectiveness is equal to or greater than the threshold, and the scenario with the maximum effectiveness satisfies the constraints (Step S5: Yes), the control decision unit 160 determines that the scenario with the maximum effectiveness as the control scenario (Step S6), and terminates the process.

[0033] If the maximum effectiveness is less than the threshold (Step S5: No), the control decision unit 160 checks whether the constraint conditions are met for the scenario in which the control is not applicable at all control times (Step S7).

[0034] If all non-applicable scenarios satisfy the constraints (Step S7: Yes), the control decision unit 160 determines all non-applicable scenarios as control scenarios (Step S8) and terminates the process.

[0035] If all non-applicable scenarios do not satisfy the constraint conditions (Step S7: No), the control decision unit 160 determines whether or not there is a constraint path scenario that satisfies the constraint conditions (Step S9).

[0036] If a constraint path scenario exists (Step S9: Yes), the control decision unit 160 decides one of the constraint path scenarios to be the control scenario (Step S10) and terminates the process. At this time, the control decision unit 160 may decide the control scenario based on the effectiveness or operation cost of the constraint path scenarios. For example, the control decision unit 160 may decide the scenario with the highest effectiveness among the constraint path scenarios to be the control scenario, or it may decide the scenario with the lowest operation cost among the constraint path scenarios to be the control scenario.

[0037] If no constraint path scenario exists (step S9: No), the control decision unit 160 performs emergency response processing, such as displaying error information on the display unit 40 to notify that no scenario satisfies the constraint conditions (step S11), and then terminates the process.

[0038] Furthermore, various data and information acquired, generated, and used in the above overall processing are recorded in the recording unit 20 as appropriate.

[0039] Figure 4 is a flowchart illustrating an example of the effectiveness calculation process in step S3 of Figure 3.

[0040] In the effectiveness calculation process, the effectiveness calculation unit 140 first selects one of the scenarios as the scenario to be calculated (step S101).

[0041] The effectiveness calculation unit 140 calculates the improvement ΔP of the index value evaluating the state of the power system 3 in the calculation target scenario from the index value in the scenario in which none of the scenarios are applied (step S102). The index value of the scenario is the sum of the individual index values ​​evaluating the state of the power system 3 at each control time when the scenario is applied (when the operation of the operation content indicated in the operation information corresponding to the scenario is applied to each electrical equipment 5). The individual index value is, for example, the value of the objective function of the optimization calculation.

[0042] Next, the effectiveness calculation unit 140 calculates the change ΔC between the operation cost of operating the electrical equipment 5 in the calculation target scenario and the operation cost in the scenario where none of the scenarios are applied (step S103). The operation cost of a scenario is the sum of the individual operation costs related to the operation at each control time when the scenario is applied. The effectiveness calculation unit 140 uses, for example, a lookup table that shows the relationship between the operation for each electrical equipment 5 and the individual operation cost related to that operation to calculate the sum of the individual operation costs of the operations performed on the electrical equipment 5 in the calculation target scenario as the operation cost of the calculation target scenario. Note that the operation cost is expressed, for example, as a value converted into a monetary amount.

[0043] The effectiveness calculation unit 140 calculates the effectiveness of the target scenario based on the improvement amount ΔP and the change amount ΔC of the target scenario (step S104). Specifically, the effectiveness calculation unit 140 calculates the effectiveness as the ratio of the improvement amount ΔP to the change amount ΔC. In other words, the effectiveness E is expressed by equation 1.

number

[0044] The effectiveness calculation unit 140 then determines whether all scenarios have been selected as scenarios to be calculated (step S105). If no scenarios have been selected (step S105: No), the process returns to step S101. On the other hand, if all scenarios have been selected (step S105: Yes), the process ends. Note that in step S101, any scenarios that have not yet been selected are selected as scenarios to be calculated.

[0045] Figure 5 is a flowchart illustrating an example of the constraint satisfaction determination process in step S3 of Figure 3.

[0046] In the constraint satisfaction determination process, the constraint satisfaction determination unit 150 first selects one of the scenarios as the scenario to be determined (step S201).

[0047] The constraint satisfaction determination unit 150 generates individual determination results that determine whether the constraint conditions are satisfied at each control time based on the operation information corresponding to the scenario to be determined (step S202). Specifically, the constraint satisfaction determination unit 150 determines whether the constraint conditions are satisfied at each control time when an operation corresponding to the operation information corresponding to the scenario to be determined is performed on the electrical equipment 5.

[0048] The constraint satisfaction determination unit 150 determines whether the target scenario satisfies the constraint conditions based on the individual determination results (step S203).

[0049] The constraint satisfaction determination unit 150 then determines whether or not all scenarios have been selected as scenarios to be judged (step S204). If no scenarios have been selected (step S204: No), the process returns to step S201. On the other hand, if all scenarios have been selected (step S204: Yes), the process ends. In step S201, any scenarios that have not yet been selected are selected as scenarios to be judged.

[0050] Figures 6 and 7 show an example of the judgment process in step S204 of Figure 5. In Figures 6 and 7 and their descriptions, "OK" may be used to indicate that the constraints are satisfied, and "NG" may be used to indicate that the constraints are not satisfied.

[0051] In the example shown in Figure 6, the constraint satisfaction determination unit 150 determines that the target scenario satisfies the constraint conditions if the individual determination result is "OK" for all control time points, and determines that the target scenario does not satisfy the constraint conditions if the individual determination result is "NG" for any one of the control time points.

[0052] In other words, in the example in Figure 6, the target scenario is determined to satisfy the constraints if the constraints are satisfied at each control time. However, for constraints such as voltage deviation, it may be permissible for the constraints not to be satisfied for a certain period of time.

[0053] In the example shown in Figure 7, the constraint satisfaction determination unit 150 determines that the target scenario satisfies the constraint conditions if the individual determination results do not show "NG" for m consecutive times or more, and determines that the target scenario does not satisfy the constraint conditions if the time-based determination results show "NG" for m consecutive times or more. In the example shown in Figure 7, m is 2, but it is not limited to 2. The value of m is set appropriately according to the allowable time during which the constraint conditions are not satisfied and the interval of the control time.

[0054] There may be multiple constraints. In this case, for example, if all constraints are satisfied, the constraint satisfaction determination unit 150 may determine that the target scenario satisfies the constraints.

[0055] As described above, in this embodiment, the scenario generation unit 120 generates a scenario for each of several future control times, indicating whether or not to use it as a target time for operating on the electrical equipment 5 included in the power system 3, for each of two or more possible values ​​of the scenario. The control planning unit 130 determines the operation content for each of the several future control times based on the system time change data for each scenario. The effectiveness calculation unit 140 calculates an effectiveness score for each scenario, evaluating the effectiveness of the scenario based on the operation cost related to operating on the electrical equipment 5 and an index value that evaluates the state of the power system 3. The control decision unit 160 determines a control scenario, which is the scenario to be used to control the power system 3, based on the effectiveness score. Therefore, it is possible to determine a control scenario while taking into account the operation cost at each of the several future control times, and thus it is possible to suppress the increase in operation costs due to changes in the state of the power system over time.

[0056] Furthermore, in this embodiment, the effectiveness of a scenario is the ratio of the improvement in the indicator value of the scenario from the indicator value of the scenario that is not applied to the change in the operating cost of the scenario that is not applied. This makes it possible to evaluate the effectiveness of a scenario more appropriately.

[0057] Furthermore, in this embodiment, the control determination unit 160 determines the scenario with the highest effectiveness among the effective levels of each scenario as the control scenario if the highest effective level is equal to or greater than the threshold. Therefore, a more appropriate scenario can be determined as the control scenario in order to reduce operational costs.

[0058] Furthermore, in this embodiment, if the maximum effectiveness is less than the threshold, the control determination unit 160 determines the fully inapplicable scenario, which is a scenario in which no operation is performed at all control times, as the control scenario. Therefore, a more appropriate scenario can be determined as the control scenario in order to reduce operational costs.

[0059] Furthermore, in this embodiment, if all non-applicable scenarios do not satisfy the constraints related to the power system, the control decision unit 160 determines one of the scenarios that satisfy the constraints as the control scenario. This makes it possible to satisfy the constraints while suppressing operating costs.

[0060] Furthermore, in this embodiment, if all non-applicable scenarios do not satisfy the constraints, the control decision unit 160 determines a control scenario based on the effectiveness or operational cost of the scenarios that satisfy the constraints. This makes it possible to determine a more appropriate scenario as the control scenario in order to suppress operational costs.

[0061] The control planning unit 130 determines the operation content based on the grid time change data so that the objective function related to the power system is optimized. This makes it possible to generate appropriate operation content and scenarios.

[0062] The embodiments of the Disclosure described above are illustrative for illustrative purposes and are not intended to limit the scope of the Disclosure to those embodiments only. Those skilled in the art can implement the Disclosure in various other forms without departing from the scope of the Disclosure. [Explanation of Symbols]

[0063] 1: Power system control device 3: Communication network 4: Power system 5: Measuring instruments 6: Electrical equipment 10: Control unit 20: Recording unit 30: Input unit 40: Display unit 50: Communication unit 110: Main control unit 120: Scenario generation unit 130: Control planning unit 140: Effectiveness calculation unit 150: Constraint satisfaction unit 160: Control decision unit

Claims

1. A power system control device having a processing unit and a recording unit, The recording unit stores system time change data, which predicts the time changes of values ​​related to the state of the power system. The aforementioned processing unit, For each of several future control times, a scenario is generated that indicates whether or not to designate it as a time for performing operations on the equipment to be operated included in the power system, for each of two or more possible values ​​of the scenario. Based on the aforementioned system time change data, the content of the operation for the target equipment at each of the target time periods is determined for each scenario. For each of the above scenarios, the effectiveness of the scenario is calculated based on the operational cost related to the operation on the equipment to be operated in that scenario and an index value that evaluates the state of the power system in that scenario. A power system control device that determines a control scenario, which is a scenario used for controlling the power system, from the scenarios based on the effectiveness.

2. The effectiveness of the scenario is the ratio of the improvement in the index value of the scenario from the index value of the all-inapplicable scenario to the change in the operating cost of the scenario from the operating cost of the all-inapplicable scenario, which is a scenario in which the operation is not performed at all of the control time intervals, according to claim 1.

3. The power system control device according to claim 1, wherein the processing unit determines the scenario with the highest maximum effectiveness among the effectiveness levels of each scenario as the control scenario if the maximum effectiveness level is equal to or greater than a threshold.

4. The power system control device according to claim 3, wherein the processing unit determines a completely inapplicable scenario, which is a scenario in which the operation is not performed at all of the plurality of control times, as the control scenario when the maximum effectiveness is less than a threshold.

5. The power system control device according to claim 4, wherein the processing unit determines one of the scenarios that satisfy the constraints as the control scenario if the all-inapplicable scenario does not satisfy the constraints relating to the power system.

6. The power system control device according to claim 5, wherein the processing unit determines the control scenario based on the effectiveness or operation cost of the scenarios that satisfy the constraints if the all-inapplicable scenarios do not satisfy the constraints.

7. The power system control device according to claim 1, wherein the processing unit determines the operation content based on the system time change data so that the objective function relating to the power system is optimized.

8. A power system control method using a power system control device having a processing unit and a recording unit, The recording unit is configured to store system time change data, which predicts the time changes of values ​​related to the state of the power system. In the aforementioned processing unit, For each of several future control times, a scenario is generated that indicates whether or not to designate it as a time for performing operations on the equipment to be operated included in the power system, for each of two or more possible values ​​of the scenario. Based on the aforementioned system time change data, the content of the operation for the target equipment at each of the target time periods is determined for each scenario. For each of the above scenarios, the effectiveness of the scenario is calculated based on the operational cost related to the operation of the equipment to be operated in that scenario and an index value that evaluates the state of the power system in that scenario. A power system control method that determines a control scenario, which is a scenario used for controlling the power system, from the scenarios based on the effectiveness level.

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