Microgrid system equipment planning support device, support system, and microgrid system equipment planning support method

Abstract

The objective of the present invention is to provide a technology that enables a user to determine appropriate microgrid system equipment. The microgrid system equipment planning support device includes: an equipment configuration candidate generation unit that generates system equipment configuration candidates combining multiple system equipment based on information about multiple system equipment of a microgrid, including power supply equipment; a magnetizing inrush current amount estimation unit that estimates an amount of magnetizing inrush current that will occur when the candidate is started up on the system, based on the candidate; and a determination unit that evaluates the appropriateness of the candidate based on the magnetizing inrush current amount of the candidate and an evaluation purpose of the candidate.

Description

[Technical field]

[0001] The present disclosure relates to a microgrid system facility planning support device, a support system, and a microgrid system facility planning support method. [Background technology]

[0002] In recent years, power system accidents or large-scale blackouts may occur due to increasingly severe heavy rainfall disasters or natural disasters such as earthquakes, and it is necessary to ensure the resilience of the power system in order to ensure a stable power supply. In addition, in order to realize a decarbonized society, the introduction of distributed power sources, including renewable energy such as solar power generation and wind power generation, and storage batteries, is being promoted. Microgrids, which utilize these distributed power sources to produce and consume electricity within a certain area and strengthen resilience, are attracting attention as a method to break away from the large-scale and centralized conventional power systems.

[0003] One example of where resilience should be ensured is rapid recovery from a power outage. When a large-scale disaster occurs in a conventional power system, it is conceivable that large-scale power generation equipment connected to the grid, such as thermal power generators, will be disconnected from the grid, resulting in a loss of power supply. Once such large-scale power generation equipment is disconnected, it takes a long time to reconnect. In contrast, microgrids utilize distributed power sources to supply power within a certain area, enabling rapid recovery from a power outage.

[0004] When constructing a microgrid, it is necessary to formulate a design plan for the system equipment after properly understanding and considering the state of the system. Therefore, various technologies have been proposed for planning support of microgrid system equipment. For example, Patent Document 1 proposes a technology that predicts load fluctuations and the like for a plan to expand charging and discharging equipment, evaluates whether voltage violations and overcurrents will occur under normal conditions, and modifies the plan as necessary. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2021 / 100200 Summary of the Invention [Problem to be solved by the invention]

[0006] In the event of an emergency such as a large-scale blackout, when power supply equipment including storage batteries is started to start up a microgrid that has been in a blackout state, an inrush current flows into the transformers in the microgrid system. If this current exceeds the capacity of the power supply, the power supply may stop and startup may fail. Therefore, when building a microgrid, it is necessary to determine the capacity of new power supply equipment and the installation locations and number of system equipment such as inrush current suppression switches, taking into account the inrush current flowing into the transformers in the system equipment.

[0007] However, the conventional technology has a problem in that it does not take into account the amount of magnetizing inrush current that occurs when starting up a microgrid from a power outage.In addition, the conventional technology has a problem in that it is not possible to determine an appropriate system equipment configuration for evaluation purposes such as cost minimization.

[0008] Therefore, the present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a technology that enables a user to determine appropriate microgrid system equipment. [Means for solving the problem]

[0009] The microgrid system equipment planning support device according to the present disclosure includes an equipment configuration candidate generation unit that generates candidates for system equipment configurations combining a plurality of system equipment including power supply equipment of a microgrid based on information about the plurality of system equipment, a magnetizing inrush current estimation unit that estimates an amount of magnetizing inrush current that will occur when the candidate is started up based on the candidate, and a determination unit that evaluates the suitability of the candidate based on the amount of magnetizing inrush current of the candidate and an evaluation purpose of the candidate. Effect of the Invention

[0010] According to the present disclosure, the amount of magnetizing inrush current generated during system startup is estimated, and the suitability of a system equipment configuration pattern is evaluated based on the amount of magnetizing inrush current and the evaluation purpose, so that a user can determine appropriate microgrid system equipment.

[0011] The objects, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a functional configuration of a microgrid system facility planning support device according to a first embodiment. [Diagram 2] 4 is a flowchart showing an operation of the microgrid system facility plan supporting device according to the first embodiment. [Diagram 3] FIG. 11 is a block diagram showing a functional configuration of a microgrid system facility planning support device according to a second embodiment. [Figure 4] 10 is a flowchart showing an operation of the microgrid system facility plan supporting device according to the second embodiment. [Diagram 5] FIG. 11 is a block diagram showing a functional configuration of a microgrid system facility planning support device according to a third embodiment. [Figure 6] 11 is a flowchart showing an operation of the microgrid system facility plan supporting device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] <Embodiment 1> 1 is a block diagram showing a functional configuration of a microgrid system equipment planning support device 1 according to the first embodiment. The microgrid system equipment planning support device 1 includes an input unit 2, a storage unit 3, an equipment configuration candidate generation unit 4, a magnetizing inrush current estimation unit 5, a determination unit 6, and an output unit 7. The storage unit 3 includes a system equipment DB 31, a calculation condition DB 32, and a calculation result DB 33. Note that DB is an abbreviation for database.

[0014] The input unit 2 receives data on system equipment of the microgrid, calculation conditions, and the like, and stores the data in the storage unit 3. Note that the system equipment of the microgrid includes, for example, switches and power supply equipment.

[0015] The data received by the input unit 2 includes, for example, the system equipment configuration of power supply equipment, the unit price of equipment to be added, the maintenance costs of existing equipment and equipment to be added, the equipment lifespan, and the characteristics of the equipment for the microgrid system equipment. The input unit 2 stores this information in the system equipment DB 31 as equipment information. The system equipment configuration includes, for example, the equipment capacity such as the power supply capacity of the system equipment and information on the connection relationship. The characteristics of the equipment include, for example, the input / output characteristics of the system equipment, the upper and lower limits of input / output, characteristics related to aging, and physical characteristics. The characteristics of the equipment may include, for a transformer included in the system equipment, a catalog value or an estimated value of the amount of magnetizing inrush current at the start-up of the microgrid system.

[0016] The data received by the input unit 2 includes, for example, system constraints, budget limits for system equipment, and constraints on installation locations and the number of units to be installed, for system equipment of a microgrid. The input unit 2 stores this information in the calculation condition DB 32 as facility plan creation conditions. The system constraints include, for example, upper and lower limits of node voltages and allowable currents of lines for system equipment.

[0017] The equipment configuration candidate generating unit 4 generates system equipment configuration candidates combining the multiple system equipment as system equipment configuration patterns based on information on the multiple system equipment of the microgrid, and stores the system equipment configuration patterns in the calculation result DB 33. The information on the multiple system equipment of the microgrid may include the equipment information stored in the system equipment DB 31, or may include the equipment information stored in the system equipment DB 31 and the equipment plan creation conditions stored in the calculation condition DB 32. For example, the equipment configuration candidate generating unit 4 generates multiple system equipment configuration patterns by combining the capacities and installation locations of system equipment to be added based on information on the multiple system equipment of the microgrid.

[0018] In addition, the facility configuration candidate generating unit 4 may adjust the power capacity of the power supply facility to be expanded in the system equipment configuration pattern so that the sum of the existing power supply capacity and the power supply capacity to be expanded is not excessively large or small with respect to the power demand or the power generation amount of the renewable energy power source. For example, the facility configuration candidate generating unit 4 may compare the maximum power demand with the sum of the existing and planned power supply capacities, and adjust the power supply capacity of the power supply facility to be expanded in the system equipment configuration pattern so that the sum of the existing and planned power supply capacities is not more than twice the maximum power demand. In addition, when information on the constraint conditions that can be determined when generating the system equipment configuration pattern is stored in the calculation condition DB 32, the facility configuration candidate generating unit 4 may adjust the power supply capacity of the power supply facility to be expanded in the system equipment configuration pattern so that the constraint conditions are satisfied.

[0019] The magnetizing inrush current estimation unit 5 estimates the amount of magnetizing inrush current that occurs at the start-up of the system of the system equipment configuration pattern, based on the system equipment configuration pattern generated by the equipment configuration candidate generation unit 4, and stores the amount of magnetizing inrush current in the calculation result DB 33. Note that the start-up of the system of the system equipment configuration pattern, that is, the start-up of the microgrid system, is the time when the power supply is started from a power outage state when the system is affected by a disaster or the like.

[0020] For example, the magnetizing inrush current amount estimating unit 5 may estimate the magnetizing inrush current amount generated in the power supply equipment at the start-up of the microgrid system by considering the characteristics and connection relationship of the installed equipment for each of a plurality of system equipment configuration patterns. Also, for example, the magnetizing inrush current amount estimating unit 5 may estimate the magnetizing inrush current amount at the start-up of the system by performing an instantaneous value simulation based on the physical characteristics and connection relationship of the system equipment. Also, for example, when catalog values ​​or estimated values ​​of the magnetizing inrush current amount for the switch of the system equipment are stored in the system equipment DB 31, the magnetizing inrush current amount estimating unit 5 may estimate the magnetizing inrush current amount at the start-up of the system based on those values. Also, for example, the magnetizing inrush current amount estimating unit 5 may estimate the magnetizing inrush current amount at the start-up of the system by multiplying the amount of current flowing through the power supply equipment of the system equipment under normal conditions by a constant, or may estimate the magnetizing inrush current amount at the start-up of the system by a method other than those.

[0021] The determination unit 6 evaluates the appropriateness of the system equipment configuration pattern based on the amount of magnetizing inrush current of the system equipment configuration pattern and the evaluation objective of the system equipment configuration pattern, and stores the evaluation result obtained thereby in the calculation result DB 33. For example, the evaluation of the appropriateness of the system equipment configuration pattern includes determining whether the amount of magnetizing inrush current estimated by the magnetizing inrush current amount estimation unit 5 is below the current allowable amount of power supply equipment of the system equipment, and determining whether the system equipment configuration is optimal for the evaluation objective.

[0022] In the first embodiment, the evaluation objective is to minimize the initial cost of adding the system equipment to be added among the system equipment configuration patterns, and the running cost of the existing system equipment and the system equipment to be added among the system equipment configuration patterns. In this case, the determination unit 6 may determine the optimality of the system equipment configuration pattern for the objective of minimizing the initial cost and the running cost as the determination of the optimality of the system equipment configuration pattern for the evaluation objective of the system equipment configuration. Note that the evaluation objective is not limited to this, and may be, for example, an evaluation objective other than the above specified by a user or the like, and the determination unit 6 may determine the optimality of the system equipment configuration pattern for the other evaluation objective.

[0023] The output unit 7 outputs the evaluation result of the determination unit 6. For example, the output unit 7 outputs and displays to a user the system equipment configuration pattern generated by the equipment configuration candidate generation unit 4, the evaluation result of the determination unit 6 for the system equipment configuration pattern, the equipment capacity and the number of installed equipment, the equipment installation position, the amount of magnetizing inrush current estimated to occur at the start-up of the microgrid system, and the index value used in determining the optimality. For example, only the system equipment configuration pattern optimal for the evaluation purpose may be displayed, or multiple system equipment configuration patterns similar to the optimal system equipment configuration pattern may be displayed together, or all system equipment configuration patterns may be displayed.

[0024] The microgrid system equipment planning support device 1 having the above-mentioned components can be realized by, for example, a computer. The system equipment DB 31, the calculation condition DB 32, and the calculation result DB 33 can be realized by, for example, a database constructed by storing data on a hard disk drive, a solid state drive (SSD), or a memory provided in the computer. The equipment configuration candidate generating unit 4, the magnetizing inrush current amount estimating unit 5, and the determining unit 6 can be realized by, for example, a processor such as a central processing unit (CPU) for performing calculation processing, and a memory such as a dynamic random access memory (DRAM). When the CPU has multiple calculation cores, the calculation speed can be increased by performing the calculations of the magnetizing inrush current amount estimating unit 5 and the determining unit 6 in parallel. Note that the equipment configuration candidate generating unit 4, the magnetizing inrush current amount estimating unit 5, and the determining unit 6 may be realized by a processing circuit.

[0025] The input unit 2 includes input devices such as a mouse, a keyboard, and a touch panel, and inputs data to the system equipment DB 31 and the calculation condition DB 32. The output unit 7 includes output devices such as a display monitor and a printer, and outputs the data stored in the system equipment DB 31, the calculation condition DB 32, and the calculation result DB 33.

[0026] <Operation> FIG. 2 is a flowchart showing the operation of the microgrid system equipment plan supporting device 1 according to the first embodiment.

[0027] In step S1, the input unit 2 receives data including equipment information and power supply device information such as the microgrid's system equipment, power demand, and power generation amount of renewable energy power sources, as well as calculation conditions, and stores the data in the memory unit 3.

[0028] The data received by the input unit 2 includes, for example, the system equipment configuration of the power supply equipment, the unit price of the equipment to be added, the maintenance costs of the existing equipment and the equipment to be added, the equipment lifespan, and the equipment characteristics for the microgrid system equipment. The input unit 2 stores this information in the system equipment DB 31 as equipment information.

[0029] The system equipment configuration includes information on the equipment capacity, physical characteristics, and connection relationships of equipment that constitutes the system, such as existing switches, power supply equipment, distribution lines, utility poles, and transformers in the system equipment. The equipment unit price includes, for example, the price per unit amount of equipment planned to be added to the system equipment. This equipment unit price may include costs such as land acquisition and installation work required when adding equipment. For example, the equipment unit price may include unit prices such as 50,000 yen / kW, 50,000 yen / kWh, and 1 million yen / unit in the case of power supply equipment, and may include unit prices such as 10,000 yen / km in the case of distribution lines.

[0030] The maintenance cost includes, for example, the price required for maintenance per unit of existing and planned additional equipment in the system equipment. For example, the maintenance cost includes unit prices such as 10,000 yen / kW-year and 500,000 yen / unit-year in the case of power supply equipment. The equipment life includes, for example, the remaining life of existing equipment in the system equipment and the life of equipment planned to be added. The equipment characteristics include, for example, the input / output characteristics, upper and lower limits of input / output, characteristics related to aging, and physical characteristics of the system equipment. The equipment characteristics may include the catalog value or approximate value of the amount of magnetizing inrush current at the start-up of the microgrid system for a transformer included in the system equipment.

[0031] The data received by the input unit 2 includes, for example, system constraints, budget limits for the system equipment, and constraints on installation locations for the microgrid system equipment. The input unit 2 stores this information in the calculation condition DB 32 as equipment plan creation conditions. The system constraints include, for example, upper and lower limits of node voltages and allowable current capacity of lines for the system equipment. The constraints on installation locations include, for example, candidate installation locations for equipment to be expanded within the system equipment, geographical constraints such as the installation area required per equipment unit, the installation height, and the upper limit of the inclination angle, and the upper limit of the number of equipment to be expanded.

[0032] In step S2, the equipment configuration candidate generator 4 generates a system equipment configuration pattern by combining a plurality of system equipment based on the equipment information in the system equipment DB 31 stored in step S1, and stores the pattern in the calculation result DB 33. The system equipment configuration pattern includes, for example, the capacity and installation location of power supply equipment such as a renewable energy power source, and the equipment capacity, installation location, and current capacity of a transformer, etc.

[0033] For example, the equipment configuration candidate generating unit 4 may generate a system equipment configuration pattern by performing a simulation in which a system equipment such as a switch is introduced at a random position in the existing system equipment configuration. Alternatively, for example, the equipment configuration candidate generating unit 4 may perform an instantaneous value simulation on the existing system equipment configuration, extract a portion where a magnetizing inrush current amount is large and measures are required, and then generate a system equipment configuration pattern. Alternatively, for example, when the magnetizing inrush current amount for a switch or the like of the system equipment is stored in the system equipment DB 31, the equipment configuration candidate generating unit 4 may generate a system equipment configuration pattern based on the magnetizing inrush current amount. Note that the generation of the system equipment configuration pattern is not limited to the above. For example, when information on a constraint condition that can be determined when generating a system equipment configuration pattern is stored in the calculation condition DB 32, the equipment configuration candidate generating unit 4 may adjust the power capacity of a power supply equipment to be added in the system equipment configuration pattern so that the constraint conditions are satisfied.

[0034] In step S3, the magnetizing inrush current estimation unit 5 estimates the amount of magnetizing inrush current that will occur during system start-up of the system equipment configuration pattern based on the system equipment configuration pattern generated by the equipment configuration candidate generation unit 4, and stores the estimated magnetizing inrush current amount in the calculation result DB33.

[0035] For example, the magnetizing inrush current amount estimating unit 5 may estimate the magnetizing inrush current amount generated in the power supply equipment at the start-up of the microgrid system based on the physical characteristics and connection relationships of the system equipment of the system equipment configuration pattern stored in the system equipment DB 31. Also, for example, the magnetizing inrush current amount estimating unit 5 may estimate the magnetizing inrush current amount by performing an instantaneous value simulation based on the physical characteristics and connection relationships of the system equipment, or may estimate the magnetizing inrush current amount by multiplying the amount of current flowing through the power supply equipment of the system equipment under normal conditions by a constant. Also, for example, when catalog values ​​or estimated values ​​of the magnetizing inrush current amount for the switch of the system equipment are stored in the system equipment DB 31, the magnetizing inrush current amount estimating unit 5 may estimate the magnetizing inrush current amount based on those values, or may estimate the magnetizing inrush current amount by a method other than these.

[0036] In step S4, the judgment unit 6 judges whether the magnetizing inrush current amount estimated by the magnetizing inrush current amount estimation unit 5 is below the current allowable capacity of the power supply equipment, and judges the optimality of the power supply equipment configuration for the evaluation purpose, for the power supply equipment configuration pattern generated by the equipment configuration candidate generation unit 4, thereby evaluating the appropriateness of the power supply equipment configuration pattern. In the first embodiment, the evaluation purpose is to minimize the initial cost at the time of adding the power supply equipment to be added among the power supply equipment configuration patterns, and the running cost of the existing power supply equipment and the power supply equipment to be added among the power supply equipment configuration patterns. Note that the evaluation purpose is not limited to this. For example, the evaluation purpose may be a multi-purpose purpose of maximizing the allowable margin, which is the difference between the current allowable capacity of the power supply equipment and the magnetizing inrush current amount, and minimizing the initial cost and the running cost.

[0037] Next, an example of determining the optimality of a system equipment configuration pattern for the purpose of minimizing the initial cost and the running cost will be described. The objective function used for the determination in this case can be formulated as in Equation (1) which aims to minimize the sum of the initial cost and the running cost. Note that C_init represents the total initial cost of the equipment related to the system equipment to be expanded, and C_run represents the total running cost incurred in the operation of the existing system equipment and the system equipment to be expanded.

[0038]

number

[0039] The initial cost (C_init) of the equipment for the system equipment to be expanded is calculated by, for example, formula (2) using the number and unit price of the system equipment including power supply equipment and switchgear. Note that n_gen[i] is the number of power supply equipment i to be expanded, n_eq[j] is the number of system equipment j to be expanded excluding power supply equipment, C_gen_init[i] is the equipment unit price of power supply equipment i, and C_eq_init[j] is the equipment unit price of system equipment j excluding power supply equipment.

[0040]

number

[0041] The unit price of equipment may include the purchase price of the grid equipment, as well as the labor costs for installing the grid equipment and the cost of acquiring the land for the installation site. When considering long-term initial costs, the cost of updating equipment during operation may be added to the unit price of equipment by adding a term to equation (2) that considers not only the capital investment that occurs at the beginning of the expansion, but also the cost of updating equipment during operation.

[0042] The running cost (C_run) of the existing and planned additional system equipment is calculated by, for example, formula (3) using the unit maintenance cost of the existing and planned additional system equipment, the cost of purchasing electricity from the power grid, and the cost of generating electricity at the power supply equipment. Note that C_gen_run[i,y] is the unit maintenance cost of the power supply equipment i in the year y, C_eq_run[j,y] is the unit maintenance cost of the system equipment j excluding the power supply equipment in the year y, E_buy[t] is the amount of purchased electricity at each time, E_gen[i,t] is the amount of generated electricity at each time by the power supply equipment i, C_buy[t] is the unit price of purchased electricity at each time, and C_fuel[i,t] is the fuel purchase cost of the power supply equipment i at each time.

[0043]

number

[0044] Note that C_fuel[i,t] may be a constant that is constant regardless of the fuel consumption amount, or may be defined as a function that changes according to the fuel consumption amount. In addition, when the power supply facility is a renewable energy power supply and a storage battery, fuel for power generation and discharge is not substantially required, so the fuel purchase cost C_fuel[i,t] may be 0. When considering selling a portion of the power generated in the microgrid system, a term related to the power sales cost may be added to formula (3).

[0045] Constraint conditions to be satisfied are set for the values ​​used in equations (2) and (3) and for values ​​associated with these values. Some examples of the constraint conditions are described below.

[0046] For example, as shown in formula (4), a constraint is set such that the amount of magnetizing inrush current during system startup does not exceed the current capacity of the equipment. Note that I_ir[i,t] represents the maximum amount of magnetizing inrush current generated in power supply equipment i at each time, and I_max[i] represents the current capacity of power supply equipment i.

[0047]

number

[0048] For example, as shown in formula (5), a constraint is set such that the power demand consumed in the microgrid matches the amount of power supplied by the power generation of the power supply facility (= purchased power amount + generated power amount). Note that E_dem[t] represents the power demand at each time.

[0049]

number

[0050] For example, a condition that the amount of power purchased from the grid does not exceed a predetermined upper limit is set as a constraint condition, as shown in Equation (6). Note that E_buy_max[t] represents the upper limit of the amount of power purchased from the grid.

[0051]

number

[0052] For example, as shown in formula (7), a condition that the amount of power generated by a power generation facility falls within a predetermined operating range is set as a constraint condition. Note that X[i,t] represents the operation value (e.g., fuel consumption and power generation) of power generation facility i at each time, X_min[i] represents the lower limit of the operation value of each facility, and X_max[i] represents the upper limit of the operation value of each facility.

[0053]

number

[0054] The determination unit 6 formulates an equipment plan using an optimization method such as mathematical programming so that the objective function is optimized (so that the objective function is minimized when the objective function is formula (1)) within a range in which the above constraint conditions are satisfied as much as possible. Such a determination unit 6 makes it possible to formulate an equipment plan that takes into account the amount of magnetizing inrush current.

[0055] Although the formula is omitted, the constraint conditions are not limited to the above. For example, when a user specifies the installation location of the grid equipment, the installation location and the upper limit of the number of grid equipment that can be installed at one location may be set as the constraint conditions. For example, when a storage battery is installed as the power supply equipment, the upper limit of the kW output and the upper and lower limits of the SOC (charging rate) may be set as the constraint conditions. For example, when considering selling a portion of the power generated in the microgrid system, the upper and lower limit constraints of the power sales amount may be set as the constraint conditions.

[0056] When determining the optimality of the system equipment configuration pattern for the purpose of minimizing costs, the determination unit 6 may calculate the value of an objective function such as formula (1) for all of the generated multiple system equipment configuration patterns, and determine the system equipment configuration pattern with the smallest value as the optimal system equipment configuration pattern. For example, the determination unit 6 may use a combinatorial optimization method such as tabu search or a genetic algorithm to calculate the capacity, number, and installation location of the system equipment to be added so as to satisfy the above constraints, and determine the optimal system equipment configuration pattern. For example, the determination unit 6 may use a method other than these to determine the optimal system equipment configuration pattern.

[0057] The determination unit 6 stores the determination result of whether the estimated magnetizing inrush current amount falls below the current allowable capacity of the power supply equipment and the determination result of the optimality of the power supply equipment configuration pattern as an evaluation result of the power supply equipment configuration pattern in the calculation result DB 33. In this case, the evaluation result may include a true / false value indicating whether the magnetizing inrush current amount satisfies a constraint condition of the power supply equipment, etc., a true / false value indicating whether the power supply equipment configuration pattern is optimal, and a value of the objective function used in the determination of the optimality.

[0058] In step S5, the determination unit 6 determines whether the evaluation of the appropriateness of the system equipment configuration patterns is completed based on the termination condition. The termination condition may be, for example, a condition that the evaluation is completed when the evaluation of the appropriateness is performed for all of the multiple system equipment configuration patterns stored in the calculation result DB 33, a condition that the evaluation is completed when the objective function values ​​of the multiple system equipment configuration patterns are sequentially calculated and the objective function values ​​do not change continuously, or a condition other than these. If it is determined that the evaluation is completed, the process proceeds to step S6, and if it is determined that the evaluation is not completed, the process returns to step S3.

[0059] In step S6, the output unit 7 outputs and displays to the user the system equipment configuration patterns generated by the equipment configuration candidate generation unit 4, the evaluation result by the determination unit 6 for the system equipment configuration patterns, the equipment capacity and the number of installed equipment, the equipment installation positions, the amount of magnetizing inrush current estimated to occur at the start-up of the microgrid system, and the index value used to determine the optimality. For example, only the system equipment configuration pattern optimal for the evaluation purpose may be displayed, or multiple system equipment configuration patterns similar to the optimal system equipment configuration pattern may be displayed together, or all system equipment configuration patterns may be displayed.

[0060] <Summary of the first embodiment> According to the microgrid system equipment planning support device 1 according to the first embodiment as described above, the amount of magnetizing inrush current generated at the time of system startup is estimated, and the suitability of a system equipment configuration pattern is evaluated based on the amount of magnetizing inrush current and the evaluation purpose. With such a configuration, the user can determine a system equipment configuration pattern in which the amount of magnetizing inrush current at the time of microgrid system startup does not exceed the current allowable capacity of the power supply equipment and is appropriate for the evaluation purpose, so that the user can determine appropriate microgrid system equipment.

[0061] <Embodiment 2> In the first embodiment, the user can determine a system equipment configuration pattern in consideration of the amount of magnetizing inrush current generated when starting up a microgrid system. However, in reality, when starting up a microgrid system, not only the amount of magnetizing inrush current is generated, but also a current amount that changes over time due to power generation by power supply equipment is generated, but the first embodiment does not take this current amount into consideration.

[0062] Therefore, in this embodiment 2, it is possible to evaluate the appropriateness of a power system equipment configuration pattern based on the amount of magnetizing inrush current of the power system equipment configuration pattern, the time series change in the amount of current generated by the power supply equipment of the power system equipment configuration pattern, and the evaluation purpose of the power system equipment configuration pattern.

[0063] Fig. 3 is a block diagram showing a functional configuration of a microgrid system equipment planning support device 1 according to the present embodiment 2. The functional configuration of Fig. 3 is similar to the functional configuration of Fig. 1 in which a current transient change estimation unit 8 is added. Hereinafter, among the components according to the present embodiment 2, components that are the same as or similar to the components described above are given the same or similar reference symbols, and different components will be mainly described.

[0064] The input unit 2, like the input unit 2 according to the first embodiment, stores data including the system equipment configuration of the power supply equipment, the unit price of the equipment to be added, the maintenance costs of the existing equipment and the equipment to be added, the equipment life, and the equipment characteristics, for the system equipment of the microgrid, in the system equipment DB 31. Also, like the input unit 2 according to the first embodiment, the input unit 2 stores data including the system constraints, the budget upper limit, and the constraints on the installation location, for the system equipment of the microgrid, in the calculation condition DB 32. In addition, the input unit 2 stores time-series data including the actual value and the future predicted value of the power demand, the power generation amount of the renewable energy power source, the charge and discharge schedule of the storage battery, and the operation schedule of the power supply equipment not subject to control, for the system equipment of the microgrid, in the load power generation DB 34.

[0065] The current transient change estimation unit 8 estimates a time series change in the amount of current generated by the power supply equipment during the system startup process of the system equipment configuration pattern based on the system equipment configuration pattern generated by the equipment configuration candidate generation unit 4, and stores the change in the amount of current in the calculation result DB 33. In the following description, the time series change in the amount of current generated by the power supply equipment during the system startup process of the system equipment configuration pattern may be referred to as a "current amount change."

[0066] For example, the current transient change estimation unit 8 may estimate the change in the amount of current by considering the data stored in the load power generation DB 34 (i.e., the power demand, the amount of power generated by the renewable energy power source, and the charging and discharging schedule of the storage battery) and the characteristics of the introduced equipment for each of a plurality of system equipment configuration patterns. Also, for example, the current transient change estimation unit 8 may estimate the change in the amount of current using a power flow calculation or an instantaneous value simulation, or may estimate the change in the amount of current using other methods.

[0067] The determination unit 6 evaluates the appropriateness of the system equipment configuration pattern based on the magnetizing inrush current amount of the system equipment configuration pattern, the current amount change of the system equipment configuration pattern, and the evaluation purpose of the system equipment configuration pattern, and stores the evaluation result obtained thereby in the calculation result DB 33. For example, the evaluation of the appropriateness of the system equipment configuration pattern includes determining whether the total current amount is below the current allowable amount of the power supply equipment of the system equipment, and determining whether the system equipment configuration is optimal for the evaluation purpose.

[0068] The combined current amount is a current amount obtained by adding together the magnetizing inrush current amount estimated by the magnetizing inrush current amount estimating unit 5 and the current amount change estimated by the current transient change estimating unit 8. For example, the total current amount may be a current amount obtained by adding together the magnetizing inrush current amount and the current amount change in consideration of the time series change in the current amount. Also, for example, the total current amount may be a current amount obtained by adding together the maximum magnetizing inrush current amount and the maximum current amount change, or may be a current amount obtained by adding together using another method.

[0069] The output unit 7 may, for example, display the change in the amount of current to the user.

[0070] <Operation> Fig. 4 is a flowchart showing the operation of the microgrid system equipment planning support device 1 according to the second embodiment. The operation in Fig. 4 is the same as the operation in Fig. 2 except that the process of step S7 is added between step S3 and step S4, and steps S1 and S4 are changed to steps S1a and S4a. Hereinafter, among the processes included in the operation in Fig. 4, components that are the same as or similar to the processes included in the operation in Fig. 2 are denoted by the same or similar reference symbols, and different components will be mainly described.

[0071] In step S1a, in addition to the processing of step S1 in the first embodiment, the input unit 2 stores in the load power generation DB 34 time series data including actual values ​​and future predicted values ​​of power demand for the microgrid system equipment, the power generation amount of the renewable energy power source, the charging and discharging schedule of the storage battery, and the operation schedule of the power supply equipment not subject to control.

[0072] In step S7, the magnetizing inrush current estimator 5 estimates a change in the amount of current based on the system equipment configuration pattern generated by the equipment configuration candidate generator 4, and stores the change in the amount of current in the calculation result DB 33. For example, the current transient change estimator 8 may estimate a change in the amount of current by considering the data stored in the load power generation DB 34 and the characteristics of the installed equipment for a plurality of system equipment configuration patterns. Also, for example, the current transient change estimator 8 may estimate a change in the amount of current by calculating a change in the amount of current in the microgrid system using a power flow calculation or an instantaneous value simulation, or may estimate a change in the amount of current by other methods.

[0073] In step S4a, the determination unit 6 performs a determination on the system equipment configuration pattern generated by the equipment configuration candidate generation unit 4 as to whether the total current amount is below the current allowable amount of the power supply equipment and a determination on the optimality of the system equipment configuration for the evaluation purpose, thereby evaluating the appropriateness of the system equipment configuration pattern. For example, the total current amount may be a current amount obtained by adding up the magnetizing inrush current amount and the current amount change in consideration of the time series change in the current amount. Also, for example, the total current amount may be a current amount obtained by adding up the maximum magnetizing inrush current amount and the maximum current amount change, or may be a current amount obtained by adding up by other methods. The process of step S4a according to the second embodiment is the same as the process of step S4 described in the first embodiment, except that the determination of the magnetizing inrush current amount is replaced with the determination of the total current amount.

[0074] <Summary of the second embodiment> According to the microgrid system equipment planning support device 1 according to the second embodiment as described above, the appropriateness of a system equipment configuration pattern is evaluated based on the magnetizing inrush current amount of the system equipment configuration pattern, the current amount change of the system equipment configuration pattern, and the evaluation purpose of the system equipment configuration pattern. According to such a configuration, the magnetizing inrush current amount and the current change can be considered in parallel, so that even when power generation by the system equipment starts during the system startup process, the user can determine an appropriate system equipment configuration pattern that does not exceed the current capacity of the power supply equipment.

[0075] In the above description, the change in the current amount that occurs separately from the magnetizing inrush current during the system startup process of the system equipment configuration pattern is described as a change in the current amount due to power generation by the power supply equipment, but is not limited to this. The change in the current amount that occurs separately from the magnetizing inrush current during the system startup process of the system equipment configuration pattern may be a change in the current amount due to power consumption by the load, or a change in the current amount due to power generation by the power supply equipment and power consumption by the load.

[0076] <Embodiment 3> In the first and second embodiments, the user can determine a system equipment configuration pattern in which the current generated when starting up the microgrid system does not exceed the current capacity of the power supply equipment. However, in the first and second embodiments, it is not possible to determine an operation method for starting up the microgrid system without violating system constraints when the microgrid system experiences a blackout due to an accident or the like.

[0077] Therefore, in the third embodiment, a system equipment configuration pattern is evaluated in the same manner as in the second embodiment, and an operation method of the system equipment configuration pattern can be determined based on the evaluated system equipment configuration pattern. Note that, although a case where the third embodiment is applied to the second embodiment will be described below, a case where the third embodiment is applied to the first embodiment will also be described below.

[0078] Fig. 5 is a block diagram showing a functional configuration of a microgrid system equipment planning support device 1 according to the present embodiment 3. The functional configuration of Fig. 5 is similar to the functional configuration of Fig. 3 in which a system operation method determination unit 9 is added. Hereinafter, among the components according to the present embodiment 3, components that are the same as or similar to the components described above are given the same or similar reference symbols, and different components will be mainly described.

[0079] The input unit 2, similar to the second embodiment, stores data regarding the microgrid system equipment including a system equipment configuration of power supply equipment, unit prices of equipment to be added, maintenance costs of existing equipment and equipment to be added, equipment lifespan, and equipment characteristics in the system equipment DB 31. Similarly to the input unit 2 according to the second embodiment, the input unit 2 stores data regarding the microgrid system equipment including system constraints, budget limits, and constraints regarding installation locations in the calculation condition DB 32. The input unit 2 may also store a plurality of typical examples of operation methods of the system equipment at the time of start-up of the microgrid system in the calculation condition DB 32 as operation patterns.

[0080] The system operation method determination unit 9 determines an operation method of the system equipment configuration pattern based on the system equipment configuration pattern evaluated by the determination unit 6. The operation method includes, for example, the order and timing of load application and power supply equipment startup, and time-series changes in the output of the power supply equipment, as procedures for starting up the microgrid system. When a consumer has power supply equipment, the operation method includes, for example, a procedure of starting up the consumer's power supply equipment to reduce the amount of current generated in the main power supply and increasing the available capacity with respect to the current tolerance upper limit of the main power supply before applying a load, in order to prevent the amount of excitation inrush current from exceeding the current tolerance of the main power supply.

[0081] The system operation method determination unit 9 may determine an operation method only for the system equipment configuration pattern determined to be optimal by the determination unit 6, or may determine an operation method for multiple or all of the system equipment configuration patterns evaluated by the determination unit 6. For example, when multiple operation patterns are stored in the calculation condition DB 32, the system operation method determination unit 9 may determine an operation method by selecting one operation pattern from the multiple operation patterns based on system information including the power demand amount of the system equipment configuration pattern, the output amount of the power supply equipment, and the geographical information of the system equipment. For example, in order to minimize the influence on the system equipment, the system operation method determination unit 9 may determine an operation pattern, which is an operation method, by performing an optimization calculation with a constraint condition that no overcurrent occurs, with the objective function being the minimization of the maximum value of the current generated in the system equipment of the system equipment configuration pattern. In addition, the system operation method determination unit 9 may determine an operation pattern by a method other than the above. In addition, the system operation method determination unit 9 may determine not only the operation method at the time of system startup, but also the operation method of the load and the power supply equipment during normal times.

[0082] The output unit 7 outputs the evaluation result of the determination unit 6, similarly to the output unit 7 according to the second embodiment. For example, the output unit 7 outputs to a user and displays the system equipment configuration pattern generated by the equipment configuration candidate generation unit 4, the evaluation result of the determination unit 6 for the system equipment configuration pattern, the equipment capacity and the number of installed equipment, the equipment installation position, the amount of magnetizing inrush current estimated to occur at the start-up of the microgrid system, the amount of current change, and the index value used in determining optimality.

[0083] Furthermore, the output unit 7 outputs the operation method determined by the system operation method determination unit 9. For example, the output unit 7 outputs and displays to a user the order and timing of load application and power supply equipment startup when system equipment is arranged in the system equipment configuration pattern determined by the determination unit 6, and information on time-series changes in the output of the power supply equipment. For example, only the system equipment configuration pattern optimal for the evaluation purpose may be displayed, or multiple system equipment configuration patterns similar to the optimal system equipment configuration pattern may be displayed together, or all system equipment configuration patterns may be displayed.

[0084] <Operation> Fig. 6 is a flowchart showing the operation of the microgrid system equipment planning support device 1 according to the third embodiment. The operation in Fig. 6 is the same as the operation in Fig. 4 except that step S8 is added between step S5 and step S6 and step S6 is changed to step S6a. Hereinafter, among the processes included in the operation in Fig. 6, components that are the same as or similar to those included in the operation in Fig. 4 are denoted by the same or similar reference symbols, and different components will be mainly described.

[0085] When it is determined in step S5 that the evaluation is completed, step S8 is performed. In step S8, the system operation method determination unit 9 determines an operation method of the system equipment configuration pattern based on the system equipment configuration pattern evaluated by the determination unit 6, and stores the operation method in the calculation result DB 33. The operation method includes, as a procedure for starting up the microgrid system, the order and timing of load application and power supply equipment startup, and time-series changes in the output of the power supply equipment.

[0086] For example, when multiple operation patterns are stored in the calculation condition DB 32, the system operation method determination unit 9 may determine the operation method by selecting one operation pattern from the multiple operation patterns based on the system scale and the configuration of the power supply equipment of the multiple operation patterns. Also, for example, in order to minimize the influence on the system equipment, the system operation method determination unit 9 may determine the operation pattern by performing an optimization calculation with the objective function being the minimization of the maximum value of the current generated in the system equipment of the system equipment configuration pattern and the constraint condition being that no overcurrent occurs. Also, the system operation method determination unit 9 may determine the operation pattern by a method other than the above.

[0087] In step S6a, the output unit 7 outputs and displays to the user the system equipment configuration pattern generated by the equipment configuration candidate generation unit 4, the evaluation result of the determination unit 6 for the system equipment configuration pattern, the equipment capacity and the number of installed equipment, the equipment installation position, the amount of magnetizing inrush current estimated to occur at the start-up of the microgrid system, and the index value used to determine the optimality, as in the second embodiment. The output unit 7 also outputs and displays to the user the order and timing of load application and power supply equipment startup when the system equipment is arranged in the system equipment configuration pattern determined by the determination unit 6 among the operation methods at the start-up of the system determined by the system operation method determination unit 9, and information on time-series changes in the output of the power supply equipment. For example, only the system equipment configuration pattern optimal for the evaluation purpose may be displayed, or multiple system equipment configuration patterns similar to the optimal system equipment configuration pattern may be displayed together, or all system equipment configuration patterns may be displayed.

[0088] <Summary of the Third Embodiment> According to the microgrid system equipment planning support device 1 according to the third embodiment as described above, an operation method of the system equipment configuration pattern is determined based on the system equipment configuration pattern evaluated by the determination unit 6. According to such a configuration, when the microgrid system experiences a blackout due to an accident or the like, it is possible to start up the microgrid system without violating system constraints.

[0089] <Modification> In the above, the microgrid system equipment planning support device 1 includes the output unit 7, but is not limited to this. For example, the support system may include the microgrid system equipment planning support device 1 without the output unit 7, and an output unit that has substantially the same function as the output unit 7 and can communicate with the microgrid system equipment planning support device 1 via a network or the like.

[0090] It should be noted that the embodiments and modifications may be freely combined, and the embodiments and modifications may be modified or omitted as appropriate.

[0091] The above description is illustrative in all respects and is not restrictive. It is understood that countless variations not illustrated can be envisioned. [Explanation of symbols]

[0092] 4 Facility configuration candidate generation unit, 5 Magnetizing inrush current estimation unit, 6 Judgment unit, 8 Current transient change estimation unit, 9 System operation method decision unit.

Claims

1. an equipment configuration candidate generation unit that generates a candidate for a system equipment configuration combining a plurality of system equipment including a power supply equipment of a microgrid based on information on the plurality of system equipment; a magnetizing inrush current amount estimation unit that estimates an amount of magnetizing inrush current that occurs when the candidate is started up on a grid based on the candidate; a determination unit that evaluates the suitability of the candidate based on the amount of the magnetizing inrush current of the candidate and an evaluation purpose of the candidate; A microgrid system facility planning support device comprising:

2. The microgrid system facility planning support device according to claim 1, The evaluation objective is to A microgrid system equipment planning support device that includes a purpose of minimizing an initial cost at the time of expanding the system equipment to be expanded among the candidates, and a running cost of the existing system equipment among the candidates and the system equipment to be expanded.

3. The microgrid system facility planning support device according to claim 1 or 2, A current transient change estimation unit is further provided for estimating a change in a current amount that occurs separately from the magnetizing inrush current amount during a system startup process of the candidate based on the candidate, The determination unit is A microgrid system facility planning support device that evaluates suitability of the candidate based on the amount of magnetizing inrush current of the candidate, a change in the amount of current of the candidate, and the evaluation purpose of the candidate.

4. The microgrid system facility planning support device according to claim 1 or 2, The microgrid system facility planning support device further includes a system operation method determination unit that determines an operation method of the candidate based on the candidate evaluated by the determination unit.

5. The microgrid system facility planning support device according to claim 1 or 2; an output unit that outputs an evaluation result of the judgment unit; A support system comprising:

6. generating candidates for a system equipment configuration combining a plurality of system equipments, including a power supply equipment, of the microgrid based on information on the plurality of system equipments; estimating an amount of magnetizing inrush current generated when starting up a system of the candidate based on the candidate; A microgrid system facility planning support method, comprising: evaluating suitability of the candidate based on the amount of magnetizing inrush current of the candidate and an evaluation purpose of the candidate.

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