Power system control device, power system control system, and power system control method

Abstract

To provide a power system control device capable of suppressing operations of target devices to be controlled related to a power system as much as possible, even when viewed chronologically over a predetermined period.SOLUTION: A power system control device 11 predicts a future system state related to a power system 10, creates a control plan based on the predicted future system state, and performs control including operations of a target device 21 to be controlled in accordance with the created control plan. The power system control device 11 includes: a constraint condition schedule setting unit 43 that sets the constraint condition including an upper limit value and a lower limit value related to whether or not the target device 21 to be controlled can be chronologically operated and the predicted control action according to the control plan; and a control action calculation unit 47 that outputs the control action related to an actual time by applying the set constraint condition to an actual time cross section. The constraint condition schedule setting unit 43 sets a constraint condition based on a control trend related to the predicted control action belonging to the predetermined period.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power system control device, a power system control system, and a power system control method for performing stabilization control of a power system. [Background technology]

[0002] Stabilization control of power systems is an important technical element for maintaining the quality of power supply in power systems. In recent years, the increase in renewable energy sources has increased the uncertainty of power systems, making it increasingly difficult for operators to devise appropriate control measures.

[0003] In the past, attempts have been made to predict the future state of the power system and apply optimal power flow calculations to the predicted future state to create a control schedule and perform online analysis in real time, thereby maintaining voltage stability and reducing transmission losses at the same time.

[0004] In this regard, the power system control technology disclosed in Patent Document 1 predicts multiple future states of the power system, creates multiple control schedules corresponding to each of the predicted future states, and selects one of the created control schedules to be adopted as a control action by referring to real-time measurement values. According to the power system control technology disclosed in Patent Document 1, even if the prediction result is locally inaccurate, it is possible to avoid the influence of the prediction error. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-4593 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the power system control technology of Patent Document 1, one control schedule to be adopted as a control action is set by referring to real-time measurement values ​​from among multiple planned control schedules. Therefore, when a certain length of predetermined period is viewed chronologically, there is a concern that the operation of controlled devices related to the power system may be fragmented and excessive, leaving room for improvement.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a power system control device, a power system control system, and a power system control method that are capable of suppressing operation of controlled devices and the like related to the power system as much as possible, even when a predetermined period is viewed chronologically from a bird's-eye view. [Means for solving the problem]

[0008] In order to solve the above problems, the power system control device according to the present invention comprises: A power system control device that predicts a future system state of a power system, formulates a control plan based on the predicted future system state, and performs control including operation of a controlled device in accordance with the formulated control plan, a constraint condition setting unit that sets constraint conditions including upper and lower limits related to time-series operatability and predicted control actions of the control target device according to the control plan; a control action calculation unit that outputs a control action related to real time by applying the constraint condition set by the constraint condition setting unit to a real-time cross section; Equipped with The most important feature of the constraint condition setting unit is that it sets the constraint condition based on a control tendency related to the predicted control action belonging to a predetermined time period. Effect of the Invention

[0009] According to the present invention, even when a predetermined period is viewed chronologically from a bird's-eye view, it is possible to suppress operation of controlled devices related to an electric power system as much as possible. Problems, configurations, and effects other than those described above will be described in detail in the following embodiments. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram functionally illustrating an overview of a power system control system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram illustrating a specific example of a predicted control action obtained by a control action calculation unit included in the power system control device according to the embodiment of the present invention. [Diagram 3] 4 is an explanatory diagram showing the predictive control action (time-dependent change characteristics of the transformer tap position with respect to the predicted time) shown in FIG. 3 together with a first upper limit value and a first lower limit value. FIG. [Figure 4] FIG. 2 is a flowchart illustrating the operation of the power system control device according to the embodiment of the present invention. [Diagram 5] FIG. 11 is an explanatory diagram illustrating a specific example of a predictive control action determined by a control action calculation unit included in the power system control device according to the first modified example of the present invention. [Figure 6A] FIG. 4 is a flow chart illustrating the operation of the power system control device according to the first modified example of the present invention. [Figure 6B] FIG. 4 is a flow chart illustrating the operation of the power system control device according to the first modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power system control device, a power system control system, and a power system control method according to embodiments of the present invention will be described in detail with reference to appropriate drawings. In the description of the power system control device and the power system control system according to the embodiment (example) of the present invention, components having common functions are given common reference numerals, and duplicated descriptions thereof will be omitted.

[0012] [Outline of power system control system 1] First, a schematic configuration of a power system control system 1 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram functionally illustrating an overview of a power system control system 1 according to an embodiment of the present invention.

[0013] As shown in FIG. 1, a power system control system 1 according to an embodiment of the present invention is configured by electronically connecting a power system 10 and a power system control device 11 via a communication medium 13 such as the Internet or a dedicated communication line to enable data exchange.

[0014] [Configuration of power system 10] The power system 10 is a concept including all the facilities related to the generation to consumption of electricity, including power generation facilities, power transmission facilities, substation facilities, demand facilities, etc. Specifically, the power system 10 is configured to include controlled devices 21 and measuring devices 23.

[0015] The controlled device 21 is a concept that includes devices that belong to the power system 10 and whose output can be changed, such as phase modifying equipment, generators, converters, storage batteries, and consumer equipment, as well as general devices whose equipment state can be changed, such as transformers with taps, circuit breakers, and switches. The controlled device 21 plays a role of performing operations according to control commands sent from the power system control device 11 or performing operations according to manual instructions.

[0016] The measuring device 23 is a device that measures the output state of a generator belonging to the power system 10, the power flow state of the power transmission and transformation equipment, and the equipment state of the controlled device 21. The measuring device 23 is provided at a predetermined measurement point in the power system 10, and plays a role of outputting measurement values ​​related to the power system 10, including the power flow value related to the controlled device 21 and the measurement values ​​of the system equipment, including the active power value and reactive power value of the load.

[0017] [Configuration of power system control device 11] 1, a weather information server 15 under the management of a weather information provider is electronically connected to the power system control device 11 so as to be able to exchange data via a communication medium 17. The weather information server 15 stores weather information for various locations that changes from moment to moment (past and future data including at least temperature, humidity, wind speed, and solar radiation).

[0018] The power system control device 11 has a control function for maintaining good power quality in the power system 10. To perform such a control function, the power system control device 11 is configured using, for example, a CPU, a memory, a storage device such as a hard disk and an SSD, and a server with a communication function (none of which are shown).

[0019] In the power system control device 11, the CPU performs predetermined processing according to the present invention in accordance with the control program stored in the memory, so that, as shown in FIG. 1, the power system control device 11 is configured to realize each of the functions of a measurement value acquisition unit 31, a current system creation unit 33, a weather information acquisition unit 35, a demand forecasting unit 37, a predicted system creation unit 39, a predicted control action calculation unit 41, a constraint condition schedule setting unit 43, a constraint condition schedule storage unit 45, a control action calculation unit 47, and a control application unit 49. The constraint schedule storage unit 45 is a functional unit realized by the storage device.

[0020] The measurement value acquiring unit 31 acquires the measurement values ​​related to the power system 10 output by the measuring device 23 via the communication medium 13. The measurement values ​​related to the power system 10 may be data directly measured by the measuring device 23, or may be data processed by the power company. The measurement values ​​acquired by the measurement value acquisition unit 31 are sent to the prediction system creation unit 39 .

[0021] The current system creation unit 33 estimates the current system state based on the real-time measurement values ​​related to the power system 10 acquired by the measurement value acquisition unit 31, and creates the estimated system cross section as the current system.

[0022] The weather information acquiring unit 35 acquires weather information (including weather forecast data) stored in the weather information server 15 via the communication medium 17. The weather information acquired by the weather information acquiring unit 35 is sent to the demand forecasting unit 37.

[0023] The demand forecasting unit 37 calculates a demand forecast value for each of a plurality of time periods in a future time series based on the weather information acquired by the weather information acquiring unit 35. The demand forecast values ​​for each of a plurality of time periods calculated by the demand forecasting unit 37 are sent to a forecast system creating unit 39.

[0024] The forecast system creation unit 39 creates a power generation plan value for each time period in the future based on the measurement values ​​related to the power system 10 acquired by the measurement value acquisition unit 31. Next, the forecast system creation unit 39 applies the demand forecast values ​​and power generation plan values ​​for each future time period to the current system based on the power generation plan values ​​for each future time period created, the current system created by the current system creation unit 33, and the demand forecast values ​​for each future time period calculated by the demand forecast unit 37. Thereafter, the predicted system creation unit 39 creates a predicted system for each time zone in the future by performing a power flow calculation with reference to the current system after the application.

[0025] The predictive control action calculation unit 41 executes an optimal power flow calculation for the predicted system for each future time period created by the predicted system creation unit 39. In this optimal power flow calculation, an operating state that optimizes a predetermined objective, such as maintaining voltage stability and reducing operating costs, is determined while satisfying constraints such as upper and lower limits of the bus voltage, an upper limit of the branch power flow, and whether or not the controlled device 21 can be operated and the controllable amount.

[0026] In this embodiment, as the constraint conditions of the controlled device 21 used in the optimal power flow calculation, constraint conditions on the operation of the controlled device 21 defined in advance in a facility database (not shown) are used. After performing the optimal power flow calculation, the predictive control action calculation unit 41 calculates the predictive control action from the difference in the system cross section before and after the optimization. In this example, a transformer and a phase modifying device are shown as the operable controlled device 21, and the transformer tap position and the phase modifying device input capacity are output as the predictive control action.

[0027] The constraint condition schedule setting unit 43 sets a constraint condition schedule for the controlled device 21 for each of the operation periods and non-operation periods (described in detail later) included in a predetermined control period (a relatively long period such as 8 hours) based on the predicted control action calculated by the predicted control action calculation unit 41. The constraint condition schedule setting unit 43 corresponds to the "constraint condition setting unit" of the present invention. The setting of the constraint schedule by the constraint schedule setting unit 43 will be described in detail later. The constraint condition schedule set by the constraint condition schedule setting unit 43 is sent to a constraint condition schedule storage unit 45 . In response to this, the constraint condition schedule storage unit 45 stores the constraint condition schedule at a specified address in the storage device.

[0028] The control action calculation unit 47 applies the constraint condition schedule related to the target predicted time (corresponding to the current time) read from the constraint condition schedule storage unit 45 to the current system created by the current system creation unit 33, and then determines, for example, a control action that maintains voltage stability and can reduce operating costs by optimal power flow calculation. Examples of the control action include discrete value commands such as tap position switching of a transformer and on / off control of a phase modifying device. This makes it possible to perform voltage control and reactive power control for the power system 10. The control action calculated by the control action calculation unit 47 is sent to a control application unit 49 .

[0029] The control application unit 49 generates a control command to be applied to the power system 10 based on the control action determined by the control action calculation unit 47 . The control command for the power system 10 generated by the control application unit 49 is sent to the controlled device 21 belonging to the power system 10 via the communication medium 13.

[0030] [Definition of terms] Here, definitions of major terms used in this specification will be explained with reference to FIG. 2 and FIG. Fig. 2 is an explanatory diagram showing a specific example of a predicted control action calculated by a control action calculation unit included in a power system control device according to an embodiment of the present invention. Fig. 3 is an explanatory diagram showing the control action (time-dependent change characteristic of a transformer tap position) shown in Fig. 2 together with a first upper limit value and a first lower limit value (constraint condition).

[0031] In this specification, "operation" refers to the operation of the controlled device 21 belonging to the power system 10. Examples of the "operation" of the controlled device 21 include control actions such as changing the tap position of a transformer and turning on and off a phase modifying device. In this specification, the term "non-operation period" means, in principle, a period during which the controlled device 21 is not operated. As an example of the "non-operation period" in this embodiment, a period during which the same predicted value appears consecutively in each chronologically consecutive prediction time (prediction slice) with respect to the predicted control action (time-dependent change characteristic of the transformer tap position with respect to the prediction time) shown in FIG. 2 is defined as the non-operation period (see FIG. 2). Also, even if a deviation value (see Tp1, Tp2, and Tp3 in FIG. 2) appears in one prediction slice while the same predicted value appears consecutively in each chronologically consecutive prediction time (prediction slice), the deviation value may be regarded as being due to a minute deviation occurring in the process of local optimization control or numerical calculation, and the deviation value may be invalidated to define the period as the non-operation period (see FIG. 2). In this specification, the term "operation period" basically means a period during which the controlled device 21 is operated. As an example of the "operation period" in this embodiment, with respect to the predicted control action (time-dependent change characteristics of the transformer tap position) shown in Fig. 2, a period during which mutually different predicted values ​​appear consecutively in individual prediction times (prediction sections) that are successive in a chronological order (the predicted values ​​of the control action change consecutively in a chronological order), in other words, a period existing between non-operation periods, is defined as the operation period. In this specification, the term "target operation period" refers to one target "operation period" when there are multiple "operation periods" during which the predicted value of the control action changes continuously over time. In this specification, the term "no-operation period of interest" refers to one "no-operation period" that is of interest when there are multiple "no-operation periods" in which the predicted value of the control action changes continuously over time. The "no-operation period", "operation period", "focused operation period" and "focused no-operation period" correspond to the "predetermined period" of the present invention. In this specification, the term "constraint condition" refers to a condition that specifies the dynamic range (control area) of a control action, which is applied to a control action belonging to a "focused operation period" or a "focused non-operation period", for example. In this specification, a "constraint schedule" refers to a set of "constraints" in which each "constraint" is arranged in chronological order. In this specification, the term "control schedule" refers to a set of control actions in which individual control actions are arranged in a time series. The "control schedule" corresponds to the "control plan" of the present invention. In this specification, the term "prediction error" refers to an error in a control action that occurs due to a difference between a system state related to a prediction time frame and a system state related to a real-time time frame. In this specification, the "correction start time" refers to, for example, the time at which it is determined that a prediction error has occurred (that a correction of a control action is required).

[0032] [Example of constraint schedule setting] Next, an example of setting the constraint condition schedule by the constraint condition schedule setting unit 43 included in the power system control device 11 according to the embodiment of the present invention will be described with reference to Figs. The constraint condition schedule setting unit 43 sets a constraint condition schedule for the controlled device 21 for each of the operation period and the non-operation period, based on the predicted control action exemplified in FIG. If the predicted time corresponding to the predicted value related to the control action belongs to a non-operation period, that is, if the controlled-target device 21 is in a non-operation state at the target predicted time t, the constraint condition schedule setting unit 43 sets a constraint condition schedule to the effect that the controlled-target device 21 cannot be operated (no operation).

[0033] However, when the predicted time corresponding to the predicted value related to the control action belongs to a non-operation period, the constraint condition schedule setting unit 43 may set the constraint condition schedule (see FIG. 3) using the first upper limit value and the first lower limit value related to the control action (transformer tap position switching) obtained according to the following (Equation 1). Uu(t)=Lu(t)=Vsc(t) (Equation 1) In (Equation 1), Uu represents the upper limit of the control action, Uu(t) represents the upper limit of the control action at the focused prediction time t, Lu represents the lower limit of the control action, Lu(t) represents the lower limit of the control action at the focused prediction time t, Vsc represents the predicted value of the control action, and Vsc(t) represents the predicted value of the control action at the focused prediction time t.

[0034] On the other hand, when the predicted time corresponding to the predicted value related to the control action belongs to the operation period, the constraint condition schedule setting unit 43 may set the constraint condition schedule (see FIG. 3) using the first upper limit value and the first lower limit value related to the control action (transformer tap position switching) obtained according to the following (Equation 2) and (Equation 3). Uu(t)=Vsc(tmax) (Equation 2) Lu(t)=Vsc(tmin) (Equation 3) In (Equation 2) and (Equation 3), tmax represents the time when the predicted value is maximum within each operation period, tmin represents the time when the predicted value is minimum within each operation period, Vsc(tmax) represents the predicted value (first upper limit value) of the control action at the focused prediction time tmax, and Vsc(tmin) represents the predicted value (first lower limit value) of the control action at the focused prediction time tmin.

[0035] In addition, in a case where, for example, a phase modifying device whose predicted control action is expressed by binary data of ON / OFF is adopted as the controlled device 21, it is difficult to set upper and lower limit values ​​for the predicted control action. In such a case, the constraint condition schedule setting unit 43 may adopt a configuration in which, when the predicted time corresponding to the predicted value related to the control action belongs to a non-operation period, the controlled device 21 (phase modifying device) is set to inoperable, whereas, when the predicted time corresponding to the predicted value related to the control action belongs to an operation period, the controlled device 21 (phase modifying device) is set to operable (with appropriate constraint conditions).

[0036] [Operation of the power system control device 11 according to the embodiment of the present invention] Next, the operation of the power system control device 11 (see FIG. 1) according to the embodiment of the present invention will be described with reference to FIG. FIG. 4 is a flowchart illustrating the operation of the power system control device 11 according to the embodiment of the present invention, and shows the flow of calculation processing by the control action calculation unit 47 among the multiple functional units provided in the power system control device 11.

[0037] 4, the control action calculation unit 47 applies the initially set constraint condition schedule related to the predicted time of interest read from the constraint condition schedule storage unit 45 to the current system created by the current system creation unit 33, in other words, applies the initially set constraint condition related to the predicted time of interest (corresponding to the current time) to the real-time section, and then executes an optimal power flow calculation. Here, the real-time section means the current system state (the power consumption state of the load in the current power transmission and distribution facility).

[0038] In step S102, control action calculation unit 47 determines whether or not the optimal power flow calculation in step S101 has converged. If the control action calculation unit 47 determines in step S102 that the optimal power flow calculation has converged (YES in step S102), it advances the process to the next step S103, whereas if the control action calculation determines that the optimal power flow calculation has not yet converged (NO in step S102), it jumps the process to step S105.

[0039] In step S103, the control action calculation unit 47 executes a voltage stability evaluation for the optimized cross section. There are various methods for the voltage stability evaluation, but here, as an example, the voltage stability evaluation using the PV curve, which is a general evaluation method, is performed. The PV curve is a characteristic curve that plots the change in bus voltage when the load changes, with the load size as a parameter. In the PV curve, the difference between the load size at the current power system operating point and the load size at the point where voltage collapse occurs is considered to be the load margin, and the larger the load margin value, the higher the voltage stability is determined to be.

[0040] In step S104, the control action calculation unit 47 determines whether the voltage stability is sufficient or not. This determination may be performed, for example, by determining whether the load margin value in the PV curve exceeds a predetermined threshold value (an appropriate set value at which the voltage stability is considered to be high). As a result of the judgment in step S104, if the control action calculation unit 47 judges that the voltage stability is sufficient (YES in step S104), it decides to adopt the proposed control action and jumps the process flow to step S110. On the other hand, if the control action calculation unit 47 judges that the voltage stability is not sufficient (NO in step S104), it advances the process flow to the next step S105.

[0041] In step S105, if the result of the judgment in step S102 is that the optimal power flow calculation has not converged, or the result of the judgment in step S104 is that the voltage stability is not sufficient, the control action calculation unit 47 applies predefined operational constraints of the controlled device 21 to perform the optimal power flow calculation.

[0042] In step S106, control action calculation unit 47 determines whether or not the optimal power flow calculation of step S105 has converged. If the control action calculation unit 47 determines in step S106 that the optimal power flow calculation has converged (YES in step S106), it proceeds to the next step S107, whereas if the control action calculation unit 47 determines that the optimal power flow calculation has not yet converged (NO in step S106), it jumps to step S109.

[0043] In step S107, the control action calculation unit 47 performs a voltage stability evaluation for the optimized cross section using a method similar to that in step S103.

[0044] In step S108, the control action calculation unit 47 determines whether or not the voltage stability is sufficient using a determination method similar to that in step S104. As a result of the judgment in step S108, if the control action calculation unit 47 judges that the voltage stability is sufficient (YES in step S108), it decides to adopt the proposed control action and jumps the process flow to step S110. On the other hand, if the control action calculation unit 47 judges that the voltage stability is not sufficient (NO in step S108), it advances the process flow to the next step S109.

[0045] In step S109, if the result of the judgment in step S106 is that the optimal power flow calculation has not converged, or the result of the judgment in step S108 is that the voltage stability is insufficient, the control action calculation unit 47 regards that an analysis error has occurred.

[0046] In step S110, the control action calculation unit 47 outputs the control action whose adoption was decided in step S104 or step S108, and then ends the flow of a series of control action calculation processes. However, if an analysis error occurs (see step S109), the control action calculation unit 47 outputs a message indicating that an analysis error has occurred.

[0047] The control action output from the control action calculation unit 47 is sent to the control application unit 49. In response to this, the control application unit 49 transmits a control command including the control action to the electric power company via the communication medium 13. In response to this, the electric power company operates a predetermined controlled device 21 belonging to the electric power system 10 based on the received control command.

[0048] According to the power system control device 11 of the embodiment of the present invention, the constraint condition schedule setting unit 43 (constraint condition setting unit) sets constraint conditions based on the control tendency related to the predicted control action belonging to a specified period, so that even when the specified period is viewed chronologically from a bird's-eye view, the operation of the controlled device 21 related to the power system 10 can be suppressed as much as possible.

[0049] Furthermore, according to the power system control device 11 of the embodiment of the present invention, when it is determined that a prediction error has occurred based on the difference between the system state related to the prediction slice and the system state related to the real-time slice (see step S102, NO in step S104), the constraint condition schedule setting unit 43 (constraint condition setting unit) sets constraint conditions taking into consideration compensation for the prediction error (see the processing in step S105, etc.). Therefore, even if a prediction error occurs, it is possible to suppress the influence of the prediction error as much as possible.

[0050] Furthermore, according to the power system control device 11 of the embodiment of the present invention, a control tendency is grasped based on the transition of the predicted values ​​of the control actions that are successive in a time series during an operation period (a specified period), and a control range related to an appropriate control action is set by utilizing the grasped control tendency. Therefore, even when a specified period is viewed chronologically from a bird's-eye view, the operation of the controlled device 21 related to the power system 10 can be suppressed as much as possible.

[0051] [Configuration of power system control device 11x according to first modification] Next, the configuration of a power system control device 11x according to a first modified example will be described with reference to FIGS. FIG. 5 is an explanatory diagram showing a state in which a control region (constraint condition) related to a control action (change characteristics over time of a transformer tap position) is defined using a second upper limit value and a second lower limit value. The power system control device 11 according to the embodiment of the present invention and the power system control device 11x according to the first modification have the same configuration of the other functional units, except for a part of the functional units (constraint condition schedule setting unit 43). Therefore, the following description will focus on the differences in some functional units (constraint condition schedule setting unit 43) instead of describing the configuration of the power system control device 11x according to the first modified example.

[0052] In the constraint condition schedule setting unit 43 provided in the power system control device 11 according to the embodiment of the present invention, when a predicted time corresponding to a predicted value related to a certain control action (transformer tap position switching) belongs to a target operation period, the respective predicted values ​​which are maximum / minimum within the target operation period are used as a first upper limit value and a first lower limit value related to the control action, and a control region related to the control action is defined by the first upper limit value and the first lower limit value, thereby setting a constraint condition schedule (see FIG. 2C ). In contrast, in the constraint condition schedule setting unit 43x provided in the power system control device 11x according to the first modification, when a predicted time corresponding to a predicted value related to a certain control action (transformer tap position switching) belongs to either a non-operation period of interest or an operation period of interest, a value obtained by adding / subtracting a predetermined margin value Val to / from the predicted value within the period to which the control action belongs is used as a second upper limit value and a second lower limit value related to the control action, and the second upper limit value and the second lower limit value are used to define a control region related to the control action, thereby setting a constraint condition schedule (see FIG. 5).

[0053] In detail, when the predicted time corresponding to the predicted value related to the control action belongs to a no-operation period, the constraint condition schedule setting unit 43x related to the first modified example sets the constraint condition schedule (see FIG. 5) using the second upper limit value and the second lower limit value related to the control action obtained according to the following (Equation 4) and (Equation 5). Uu(t)=Vsc(t)+Val (Equation 4) Lu(t)=Vsc(t)-Val (Equation 5) In (Equation 4) and (Equation 5), Val represents a predetermined margin value for a predicted value related to a control action. The margin value Val is not particularly limited, but may be set to, for example, the minimum unit of a control action (amount of control related to the controlled device 21). However, in a case where the predicted value Vsc(t) of the control action at the target prediction time t deviates from the operational constraints (upper and lower limits) of the controlled device 21 predefined in the equipment database, the predetermined margin value Val is set to zero (Val=0).

[0054] On the other hand, when the predicted time corresponding to the predicted value related to the control action belongs to the operation period, the constraint condition schedule setting unit 43x related to the first modified example performs setting to relax the constraint condition schedule (see FIG. 5) by using the second upper limit value and the second lower limit value related to the control action obtained according to the following (Equation 6) and (Equation 7). Uu(t)=Vsc(tmax)+Val (Equation 6) Lu(t)=Vsc(tmin)-Val (Eq. 7) However, in a case where either the predicted value Vsc(tmax) of the control action at time tmax, at which the predicted value is maximum within the operation period of interest, or the predicted value Vsc(tmin) of the control action at time tmin, at which the predicted value is minimum within the operation period of interest, deviates from the operational constraints (upper and lower limits) of the controlled device 21 predefined in the equipment database, the predetermined margin value Val is set to a value of zero (Val=0).

[0055] In addition, in a case where, for example, a phase modifying device in which a predicted control action is expressed by binary data of ON / OFF is adopted as the controlled device 21, it is difficult to set an upper limit value and a lower limit value for the predicted control action. In such a case, the constraint condition schedule setting unit 43x according to the first modified example may be configured to set the controlled device 21 (phase modifying device) to inoperable when the predicted time corresponding to the predicted value related to the control action belongs to a non-operation period, and to set the controlled device 21 (phase modifying device) to operable (with appropriate constraint conditions) when the predicted time corresponding to the predicted value related to the control action belongs to an operation period.

[0056] [Operation of the power system control device 11x according to the first modified example] Next, the operation of the power system control device 11x (see FIG. 1) according to the first modification will be described with reference to FIG. 6A and FIG. 6B. 6A and 6B are flowcharts illustrating the operation of a power system control device 11x according to a first modified example of the present invention, and show the flow of calculation processing by a control action calculation unit 47x among multiple functional units provided in the power system control device 11x.

[0057] In step S201 shown in FIG. 6A, the control action calculation unit 47x applies the initially set constraint condition schedule related to the predicted time of interest read from the constraint condition schedule storage unit 45 to the current system created by the current system creation unit 33, in other words, applies the initially set constraint condition schedule related to the predicted time of interest (corresponding to the current time) to the real-time section, and then performs an optimal power flow calculation.

[0058] In step S202, the control action calculation unit 47x determines whether or not the optimal power flow calculation in step S201 has converged. If the control action calculation unit 47x determines in step S202 that the optimal power flow calculation has converged (YES in step S202), it advances the process to the next step S203, whereas if the control action calculation unit 47x determines that the optimal power flow calculation has not yet converged (NO in step S202), it jumps the process to step S205.

[0059] In step S203, the control action calculation unit 47x performs a voltage stability evaluation for the optimized cross section. Here, as an example, the voltage stability evaluation is performed using the PV curve, which is a general evaluation method.

[0060] In step S204, the control action calculation unit 47x determines whether the voltage stability is sufficient or not. This determination may be performed by determining whether the load margin value in the PV curve exceeds a predetermined threshold value (a suitable set value at which the voltage stability is considered to be high) in the same manner as described above. As a result of the judgment in step S204, if the control action calculation unit 47x judges that the voltage stability is sufficient (YES in step S204), it decides to adopt the proposed control action and jumps the process flow to step S110. On the other hand, if the control action calculation unit 47x judges that the voltage stability is not sufficient (NO in step S204), it advances the process flow to the next step S205.

[0061] In step S205, if the result of the judgment in step S202 is that the optimal power flow calculation has not converged, or the result of the judgment in step S204 is that the voltage stability is insufficient (in other words, if a prediction error is deemed to have occurred), the control action calculation unit 47x applies a predetermined margin value Val (see Figure 5) to the constraint condition schedule that is initially set based on the predictive control action calculated by the predictive control action calculation unit 41, thereby applying the relaxed constraint condition to the real-time cross section and performing the optimal power flow calculation.

[0062] In step S206, the control action calculation unit 47x determines whether or not the optimal power flow calculation in step S205 has converged. As a result of the judgment in step S206, if the control action calculation unit 47x judges that the optimal power flow calculation has converged (YES in step S206), the control action calculation unit 47x advances the process to the next step S207, whereas if the control action calculation judges that the optimal power flow calculation has not yet converged (NO in step S206), the control action calculation unit 47x jumps the process to step S209.

[0063] In step S207, the control action calculation unit 47x performs a voltage stability evaluation for the optimized cross section using a method similar to that in step S203.

[0064] In step S208, the control action calculation unit 47x determines whether or not the voltage stability is sufficient using the determination method similar to that in step S204. As a result of the judgment in step S208, if the control action calculation unit 47x judges that the voltage stability is sufficient (YES in step S208), it decides to adopt the proposed control action and jumps the process flow to step S110. On the other hand, if the control action calculation unit 47x judges that the voltage stability is not sufficient (NO in step S208), it advances the process flow to the next step S209.

[0065] In step S209, if the result of the judgment in step S206 is that the optimal power flow calculation has not converged, or the result of the judgment in step S208 is that the voltage stability is insufficient (in other words, if the prediction error still cannot be compensated for even when the relaxed constraint conditions are applied), the control action calculation unit 47x executes the optimal power flow calculation by applying predefined operational constraint conditions of the controlled device 21.

[0066] In step S210, the control action calculation unit 47x determines whether or not the optimal power flow calculation in step S209 has converged. As a result of the judgment in step S210, if the control action calculation unit 47x judges that the optimal power flow calculation has converged (YES in step S210), it advances the process to the next step S211. On the other hand, if the control action calculation unit 47x judges that the optimal power flow calculation has not yet converged (NO in step S210), it jumps the process to step S213.

[0067] In step S211, the control action calculation unit 47x performs a voltage stability evaluation for the optimization cross section using a method similar to that in step S203.

[0068] In step S212, the control action calculation unit 47x determines whether or not the voltage stability is sufficient using the determination method similar to that in step S204. As a result of the judgment in step S212, if the control action calculation unit 47x judges that the voltage stability is sufficient (YES in step S212), it decides to adopt the proposed control action and jumps the process flow to step S110. On the other hand, if the control action calculation unit 47x judges that the voltage stability is not sufficient (NO in step S212), it advances the process flow to the next step S213.

[0069] In step S213, if the result of the judgment in step S210 is that the optimal power flow calculation has not converged, or the result of the judgment in step S212 is that the voltage stability is insufficient, the control action calculation unit 47x considers that an analysis error has occurred.

[0070] In step S110, the control action calculation unit 47x outputs the control action whose adoption was decided in step S204, step S208, or step S212, and then ends the flow of a series of control action calculation processes. However, if an analysis error occurs (see step S213), the control action calculation unit 47x outputs a message indicating that an analysis error has occurred.

[0071] The control action output from the control action calculation unit 47x is sent to the control application unit 49. In response to this, the control application unit 49 transmits a control command including the control action to the electric power company via the communication medium 13. In response to this, the electric power company operates a predetermined controlled device 21 belonging to the electric power system 10 based on the received control command.

[0072] According to the power system control device 11x of the first modification, when it is determined that a prediction error has occurred based on the difference between the system state related to the prediction slice and the system state related to the real-time slice (see step S202, NO in step S204), the constraint condition schedule setting unit 43 (constraint condition setting unit) sets relaxed constraint conditions taking into account compensation for the prediction error (see the processing of step S205, etc.). Therefore, even if a prediction error occurs, it is possible to suppress the influence of the prediction error as much as possible.

[0073] Moreover, according to the power system control device 11x of the first modification, when a predicted time corresponding to a predicted value related to a certain control action (transformer tap position switching) belongs to either a non-operation period of interest or an operation period of interest, a value obtained by adding / subtracting a predetermined margin value Val to / from the predicted value within the period to which the control action belongs is used as a second upper limit value and a second lower limit value related to the control action, and a control region related to the control action is defined by the second upper limit value and the second lower limit value, thereby setting a constraint condition schedule (see FIG. 5). Therefore, compared to the power system control device 11, it is possible to relax the constraint condition related to the control action. In short, according to the power system control device 11x of the first modification, even if a prediction error occurs in the real-time analysis and the optimal power flow calculation does not converge or it is determined that the voltage stability is insufficient, the control tendency is grasped over a predetermined period of a certain length and the grasped control tendency is used to set a control region (relaxed constraint condition) for an appropriate control action, so that even when the predetermined period is viewed chronologically as a whole, the operation of the controlled device 21 related to the power system can be suppressed as much as possible.

[0074] [Configuration of power system control device 11y according to the second modified example] Next, the configuration of a power system control device 11y according to a second modification will be described with reference to FIG. The power system control device 11 according to the embodiment of the present invention and a power system control device 11y according to the second modification have the same configuration of functional units, except for a part of functional units (constraint condition schedule setting unit 43). Therefore, the following description will focus on the differences in some functional units (constraint condition schedule setting unit 43) instead of describing the configuration of the power system control device 11y according to the second modified example.

[0075] In the constraint condition schedule setting unit 43 provided in the power system control device 11 according to the embodiment of the present invention, when a predicted time corresponding to a predicted value related to a certain control action (transformer tap position switching) belongs to a target operation period, the respective predicted values ​​which are maximum / minimum within the target operation period are used as a first upper limit value and a first lower limit value related to the control action, and a control region (constraint condition) related to the control action is specified by the first upper limit value and the first lower limit value, thereby setting a constraint condition schedule (see FIG. 2C ). In contrast, in the constraint condition schedule setting unit 43y provided in the power system control device 11y according to the second modification, when a predicted time corresponding to a predicted value related to a certain control action (switching of transformer tap position) belongs to either a target non-operation period or a target operation period, the constraint condition (first upper limit value / first lower limit value) in the period to which the predicted time belongs is subjected to extended correction related to the constraint condition (first upper limit value / first lower limit value) by adding / subtracting the difference Vdf between the measured value and the predicted value at the correction start time tas. Thus, the constraint condition schedule is set.

[0076] In detail, the constraint condition schedule setting unit 43y in the second modified example sets a constraint condition schedule in accordance with the extended and corrected constraint condition (first upper limit value / first lower limit value) obtained according to the following (Equation 8) and (Equation 9) when the predicted time corresponding to the predicted value related to the control action belongs to either a non-operation period or an operation period. Uu(t)=Usc(t)+[Vnw(tas)-Vsc(tas)] (Equation 8) Lu(t)=Lsc(t)-[Vnw(tas)-Vsc(tas)] (Equation 9) In (Equation 8) and (Equation 9), Uu(t) represents the corrected upper limit value of the control action at the focused prediction time t, Usc(t) represents the constraint condition at the focused prediction time t (predicted upper limit value: first upper limit value), Vnw(tas) represents the measured value of the control action at the correction start time tas, Vsc(tas) represents the predicted value of the control action at the correction start time tas, Lu(t) represents the corrected lower limit value of the control action at the focused prediction time t, and Lsc(t) represents the constraint condition at the focused prediction time t (predicted lower limit value: first lower limit value).

[0077] However, in a case where either the corrected upper limit value Uu(t) or the corrected lower limit value Lu(t) of the control action at the target prediction time t deviates from the operational constraints (upper limit value and lower limit value) of the controlled device 21 predefined in the equipment database, the constraints (first upper limit value / first lower limit value) are applied as they are without performing an extended correction of the constraints (first upper limit value / first lower limit value).

[0078] [Operation of the power system control device 11y according to the second modified example] Next, the operation of the power system control device 11y (see FIG. 1) according to the second modification will be described in comparison with the operation of the power system control device 11x (see FIG. 6A) according to the first modification.

[0079] In the power system control device 11x according to the first modified example, in step S205 shown in FIG. 6A, if the result of the judgment in step S202 is that the optimal power flow calculation has not converged, or the result of the judgment in step S204 is that the voltage stability is insufficient (in other words, if it is deemed that a prediction error has occurred), the control action calculation unit 47x applies a predetermined margin value Val (see FIG. 5) to the constraint condition schedule initially set based on the predictive control action calculated by the predictive control action calculation unit 41, thereby applying the relaxed constraint condition to the real-time cross section and executing the optimal power flow calculation.

[0080] In contrast, in the power system control device 11y according to the second modification, in step S205 shown in FIG. 6A, if the result of the judgment in step S202 indicates that the optimal power flow calculation has not converged, or the result of the judgment in step S204 indicates that the voltage stability is insufficient (in other words, if a prediction error is deemed to have occurred), the control action calculation unit 47y performs extended correction related to the constraint condition (first upper limit value / first lower limit value) by adding / subtracting the difference Vdf between the measured value and the predicted value at the correction start time tas (which is the time when it was determined that a prediction error has occurred) for the constraint condition (first upper limit value / first lower limit value) related to the target prediction time t (corresponding to the current time) in the initially set constraint condition schedule. Thereafter, the control action calculation unit 47y applies the expanded and corrected constraint condition (first upper limit value+α / first lower limit value-α: α=[Vnw(tas)-Vsc(tas)]) to the real-time cross section and then performs an optimal power flow calculation.

[0081] According to the power system control device 11y of the second modification, when it is determined that a prediction error has occurred based on the difference between the system state related to the prediction slice and the system state related to the real-time slice (see NO in steps S202 and S204), the constraint condition schedule setting unit 43 (constraint condition setting unit) sets a constraint condition taking into consideration compensation for the prediction error (extended correction related to the constraint condition (control range defined by the first upper limit value / first lower limit value)). Therefore, even if a prediction error occurs, it is possible to suppress the influence of the prediction error as much as possible.

[0082] Furthermore, in the power system control device 11y of the second modification, when performing an extended correction of the constraint condition (control region defined by the first upper limit value / first lower limit value), the constraint condition schedule setting unit 43 (constraint condition setting unit) increases the amount of the extended correction based on the magnitude of the difference between the measured value and the predicted value related to the control action (the difference Vdf between the measured value and the predicted value at the correction start time tas), as the difference Vdf increases. Therefore, even if a prediction error occurs, the effect of suppressing the influence associated with the prediction error as much as possible can be further enhanced.

[0083] Furthermore, according to the power system control device 11y of the second modification, when a prediction time corresponding to a predicted value related to a certain control action (switching of transformer tap position) belongs to either a non-operation period of interest or an operation period of interest, an extended correction related to the constraint condition (first upper limit value / first lower limit value) is performed by adding / subtracting the difference Vdf between the measured value and the predicted value at the correction start time tas (the time when it is determined that a prediction error has occurred) for the constraint condition (first upper limit value / first lower limit value) in the period to which the constraint condition belongs, thereby setting a constraint condition schedule. Therefore, compared to the power system control devices 11 and 11x, it is possible to realize power stabilization control that takes into consideration the difference Vdf between the measured value and the predicted value, i.e., compensation for the prediction error.

[0084] [Configuration, Functions and Effects of Power System Control System 1 According to the Present Invention] The power system control system 1 according to the present invention is premised on a power system control system 1 including a power system control device 11 that predicts a future system state of a power system 10, formulates a control plan based on the predicted future system state, and performs control including operation of a controlled device 21 in accordance with the formulated control plan. The power system control device 11 includes a constraint condition schedule setting unit 43 (constraint condition setting unit) that sets constraint conditions including time-series operation propriety of the controlled device 21 and upper and lower limits related to a predicted control action in accordance with the control plan, and a control action calculation unit 47 that outputs a control action related to real time by applying the constraint conditions set by the constraint condition schedule setting unit 43 to a real-time cross section, and the constraint condition schedule setting unit 43 sets the constraint conditions based on the control tendency related to the predicted control action belonging to a specified period. According to the power system control system 1 of the present invention, the constraint condition schedule setting unit 43 (constraint condition setting unit) sets constraint conditions based on the control tendency related to the predicted control action belonging to a specified period, so that even when the specified period is viewed chronologically from a bird's-eye view, the operation of the controlled device 21 related to the power system 10 can be suppressed as much as possible.

[0085] [Configuration, operation and effect of the power system control method according to the present invention] The power system control method according to the present invention is based on a power system control method used in a power system control device 11 that predicts a future system state of a power system 10, formulates a control plan based on the predicted future system state, and performs control including operation of a controlled device 21 in accordance with the formulated control plan. The power system control method according to the present invention includes a step of setting constraint conditions including upper and lower limit values ​​related to the time-series operatability of the controlled device 21 and the predicted control action in accordance with the control plan, and a step of outputting a control action related to real time by applying the set constraint conditions to a real-time cross section, in which the constraint conditions are set based on a control tendency related to the predicted control action belonging to a predetermined period. According to the power system control method of the present invention, in the step of setting the constraint conditions, the constraint conditions are set based on the control tendency related to the predicted control action belonging to a specified period. Therefore, even when the specified period is viewed chronologically from a bird's-eye view, the operation of the controlled device 21 related to the power system 10 can be suppressed as much as possible.

[0086] Other embodiments The above-described embodiments are merely examples of the realization of the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these embodiments. The present invention can be embodied in various forms without departing from the spirit or main characteristics of the present invention.

[0087] In addition, a part of the configuration of the embodiment described here can be replaced with the configuration of another embodiment, and a configuration of one embodiment can be added to a configuration of another embodiment. Furthermore, a part of the configuration of each embodiment can be added to, deleted from, or replaced with another configuration. [Explanation of symbols]

[0088] 1 Power system control system 10 Power system 11. Power System Control Device According to the Embodiment 11x Power system control device according to a first modification 11y Power system control device according to a second modified example 21 Controlled Equipment 23 Measuring Instruments 31 Measurement value acquisition section 33 Current System Creation Department 35 Weather Information Acquisition Department 37 Demand Forecasting Department 39 Prediction System Creation Department 41 Predictive control action calculation unit 43 Constraint condition schedule setting unit (constraint condition setting unit) according to the embodiment 43x Constraint condition schedule setting unit (constraint condition setting unit) according to the first modified example 43y Constraint condition schedule setting unit (constraint condition setting unit) according to the second modified example 45 Constraint Schedule Storage 47 Control action calculation unit according to the embodiment 47x Control action calculation unit according to the first modification 47y Control action calculation unit according to the second modified example 49 Control Application Section

Claims

1. A power system control device that predicts a future system state of a power system, formulates a control plan based on the predicted future system state, and performs control including operation of a controlled device in accordance with the formulated control plan, a constraint condition setting unit that sets constraint conditions including upper and lower limits related to time-series operatability and predicted control actions of the control target device according to the control plan; a control action calculation unit that outputs a control action related to real time by applying the constraint condition set by the constraint condition setting unit to a real-time cross section; Equipped with The constraint condition setting unit sets the constraint condition based on a control tendency related to the predicted control action belonging to a predetermined time period. A power system control device comprising:

2. The power system control device according to claim 1, The constraint condition setting unit: When it is determined that a prediction error has occurred based on a difference between a system state related to a prediction time section and a system state related to a real-time time section, the constraint condition is set in consideration of compensation for the prediction error. A power system control device comprising:

3. The power system control device according to claim 1, The constraint condition setting unit: When it is determined that a prediction error has occurred based on the difference between the system state related to the prediction section and the system state related to the real-time section, the control region defined by the upper limit value and the lower limit value related to the prediction control action is expanded and corrected, thereby setting the constraint condition taking into consideration compensation for the prediction error. A power system control device comprising:

4. The power system control device according to claim 3, The constraint condition setting unit: When performing the expansion correction of the control region, the amount of the expansion correction is increased as the difference between the measured value and the predicted value related to the control action increases based on the magnitude of the difference. A power system control device comprising:

5. A power system control system including a power system control device that predicts a future system state of a power system, formulates a control plan based on the predicted future system state, and performs control including operation of a controlled device in accordance with the formulated control plan, The power system control device comprises: a constraint condition setting unit that sets constraint conditions including upper and lower limits related to time-series operatability and predicted control actions of the control target device according to the control plan; a control action calculation unit that outputs a control action related to real time by applying the constraint condition set by the constraint condition setting unit to a real-time cross section; Equipped with The constraint condition setting unit sets the constraint condition based on a control tendency related to the predicted control action belonging to a predetermined time period. A power system control system comprising:

6. A power system control method for use in a power system control device, which predicts a future system state of a power system, formulates a control plan based on the predicted future system state, and performs control including operation of a controlled device in accordance with the formulated control plan, setting constraint conditions including upper and lower limits relating to time-series operation of the control target device and predicted control actions according to the control plan; and outputting a control action related to the real time by applying the set constraint condition to a real time slice, In the step of setting the constraint condition, the constraint condition is set based on a control tendency related to the predicted control action belonging to a predetermined period. A power system control method comprising:

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