Distributed Energy Resource Management Device, Distributed Energy Resource Management System, and Distributed Energy Resource Management Program

Abstract

To obtain a distributed type energy resource management device capable of maintaining a voltage of a system in an appropriate range even when a power generation amount of photovoltaic power generation is changed.SOLUTION: A distributed type energy resource management device 1 includes: an information acquisition unit 11 for acquiring information on a distributed type energy resource and information on a power distribution system; a photovoltaic power generation output prediction unit 12 for predicting an output maximum value and an output minimum value of photovoltaic power generation included in the distributed type energy resource; an optimal power flow calculation unit 13 for performing optimal power flow calculation by using information acquired by the information acquisition unit and the output maximum value and the output minimum value predicted by the photovoltaic power generation output prediction unit to determine a control amount of the distributed type energy resource; a setting value calculation unit 14 for determining a setting value of the distributed type energy resource based on a voltage distribution of the power distribution system; and a control information output unit 15 for notifying the distributed type energy resource of the control amount determined by the optimum power flow calculation unit and the setting value determined by the setting value calculation unit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a distributed energy resource management device, a distributed energy resource management system, and a distributed energy resource management program for managing distributed energy resources (DERs: Distributed Energy Resources).

Background Art

[0002] In recent years, the number of ordinary households introducing solar power generation equipment has been increasing. Among the electric power generated by the solar power generation equipment of ordinary households, surplus electric power that cannot be consumed within the household is sold to the electric power company via the power distribution system, stored in a storage battery, or consumed during a time period when the power generation amount is small. There are also electric power companies equipped with solar power generation equipment.

[0003] Here, since the power generation amount of solar power generation varies greatly depending on the weather, measures are required to prevent the current and voltage of the power transmission and distribution system from deviating from the proper state due to this influence.

[0004] For example, Patent Document 1 discloses a technique capable of achieving the maintenance of the balance between the voltage and the reactive power of the power system even when output fluctuations such as renewable energy occur. The voltage reactive power operation support and monitoring control device described in Patent Document 1 is installed at various locations in the system, and predicts the operation of individual control devices that individually control the voltage and the like at the installation location, using the measured values and predicted values of the system, the predicted values of the output fluctuations of renewable energy, and the like, and provides the operation prediction results to the operator. Further, the deadband width set for the individual control device is calculated using the operation prediction results and transmitted to the individual control device.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The voltage and reactive power operation support and monitoring control device described in Patent Document 1 predicts the operation of the individual control device using the predicted value of the output fluctuation of renewable energy created in advance, and calculates the deadband width to be set. When the weather assumed when calculating the predicted value of the output fluctuation of renewable energy used for operation prediction is different from the actual weather, it becomes difficult to maintain the voltage in an appropriate state.

[0007] The present disclosure has been made in view of the above, and an object thereof is to obtain a distributed energy resource management device that can maintain the voltage of the power distribution system within an appropriate range even when the power generation amount of solar power generation connected to the system changes.

Means for Solving the Problems

[0008] In order to solve the above-described problems and achieve the object, a distributed energy resource management device according to the present disclosure includes an information acquisition unit that acquires information on distributed energy resources connected to a power distribution system and information on the power distribution system, and a solar power generation output prediction unit that predicts the maximum output value and the minimum output value of solar power generation included in the distributed energy resources connected to the power distribution system. Further, the distributed energy resource management device uses the information acquired by the information acquisition unit and the maximum output value and the minimum output value predicted by the solar power generation output prediction unit to , optimal power flow calculation under the output maximum condition where the output of solar power generation reaches the output maximum value, and under the output minimum condition where the output of solar power generation reaches the output minimum value perform optimal power flow calculation and determine the control amount of the distributed energy resources connected to the power distribution system For each of the output maximum condition and the output minimum condition An optimal power flow calculation unit, a setting value calculation unit that determines the setting value of the distributed energy resource based on the voltage distribution of the power distribution system obtained by the optimal power flow calculation, and a control information output unit that notifies the distributed energy resource of the control amount determined by the optimal power flow calculation unit and the setting value determined by the setting value calculation unit. For each of the output maximum condition and the output minimum condition

Effects of the Invention

[0009] ​According to the distributed energy resource management device according to the present disclosure, even when the power generation amount of solar power generation connected to the power system changes, the voltage of the power system can be maintained within an appropriate range, and this has the effect of maintaining the voltage of the power system within an appropriate range.

Brief Description of Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiment for Carrying Out the Invention

[0011] Hereinafter, a distributed energy resource management device, a distributed energy resource management system, and a distributed energy resource management program according to embodiments of the present disclosure will be described in detail with reference to the drawings.

[0012] Embodiment 1. FIG. 1 is a diagram showing a configuration example of a distributed energy resource management system 100 according to Embodiment 1.

[0013] As shown in FIG. 1, the distributed energy resource management system 100 includes a distributed energy resource management device 1, a VPP (Virtual Power Plant) aggregator system 2, and a distribution automation system 3.

[0014] The distributed energy resource management system 100 shown in FIG. 1 corresponds to a system called DERMS (Distributed Energy Resource Management Systems). DERMS collects information such as the operating states of distributed energy resources such as solar power generation (PV: PhotoVoltaic power generation system) and storage batteries, and manages them integrally. As needed, it controls the DER so that the current and voltage of the power transmission and distribution system to which the DER is connected are maintained within an appropriate range.

[0015] As will be described in detail later, the distributed energy resource management device 1 transmits control commands for DERs installed in the homes of customers, commands for setting values, etc. via the VPP aggregator system 2. Further, the distributed energy resource management device 1 transmits control commands for DERs and step voltage regulators (SVRs) installed by power utilities, etc., setting values, etc. via the distribution automation system 3. This prevents the current and voltage of the distribution system from deviating from the appropriate ranges determined. Also, regarding solar power generation among DERs, where the amount of power output to the distribution system fluctuates greatly depending on the weather, the distributed energy resource management device 1 predicts the amount of power output to the distribution system, and based on the prediction results, controls each DER connected to the distribution system, determines and notifies the setting values necessary for the DERs to operate, etc. This ensures that even when the amount of power generated by solar power generation fluctuates due to changes in weather and the amount of power output to the distribution system varies, the current and voltage of the distribution system do not deviate from the appropriate ranges. In the following description, the power output from the PV among DERs to the distribution system may be referred to as "PV output".

[0016] The VPP aggregator system 2 manages and controls DERs installed at the customer, etc. In Fig. 1, a household EV (Electric Vehicle) charger 54 and a household battery 55 are described as examples of DERs managed by the VPP aggregator system 2. Also, when the VPP aggregator system 2 satisfies defined conditions, it transmits information regarding the DERs to be managed to the distributed energy resource management device 1 as management device information. The defined conditions include, for example, when it receives an instruction or request from the distributed energy resource management device 1, or when it reaches a preset time or timing (once a day, every 30 minutes, etc.). In the example shown in Fig. 1, the DER controllable range is transmitted from the VPP aggregator system 2 to the distributed energy resource management device 1 as management device information. Here, the DER controllable range refers to the controllable range of active power, reactive power, and apparent power that the DER outputs to the power distribution system. Note that the DERs managed by the VPP aggregator system 2 may include PV. Also, the VPP aggregator system 2 receives the reactive power control amount and the active power control amount (described as the power control amount in Fig. 1) and the setting value, which will be described later, from the distributed energy resource management device 1, and controls the DERs based on the received information.

[0017] The distribution automation system 3 manages and controls devices such as DERs and SVRs installed by the electric power company, etc. to maintain the proper state of the current and voltage of the power distribution system. In Fig. 1, a solar power generation facility (PV) 51, an EV charger 52, a system battery 53, and an SVR 4 are described as examples of devices managed by the distribution automation system 3.

[0018] In addition, when the power distribution automation system 3 meets the defined conditions, it transmits information regarding the devices and power distribution systems to be managed as management target information to the distributed energy resource management device 1. The defined conditions include, for example, when receiving an instruction or request from the distributed energy resource management device 1, or when it reaches a preset time or timing (once a day, every 30 minutes, etc.). In the example shown in FIG. 1, the system information, load information, power generation actual value, DER controllable range, and SVR information are transmitted from the power distribution automation system 3 to the distributed energy resource management device 1 as management target information. Here, the system information includes power distribution line information indicating the topology of the power distribution system, the impedance of each power distribution line constituting the power distribution system, information on the location of the SVR, etc. The load information is information on the power consumption of consumers, indicating how much power the consumers are consuming at what time. The SVR information is information on the functions of the SVR, etc. Note that instead of the power generation actual value, the actual value of the power output from a power generation facility such as a PV to the power distribution system may be transmitted. Also, the power distribution automation system 3 receives the reactive power control amount and active power control amount (described as the power control amount in FIG. 1) and the setting value, which will be described later, from the distributed energy resource management device 1, and controls the DER based on the received information.

[0019] Here, the DER managed by the VPP aggregator system 2 and the DER managed by the power distribution automation system 3 are equipped with smart inverters having a communication function. The smart inverter of the DER can receive control commands for active power and reactive power from the outside or receive commands for the setting values of local control using the communication function. In local control, the smart inverter of the DER controls the voltage output to the power distribution system, etc., based on its own judgment according to the setting value commanded from the outside. Examples of this local control include maximum output limit control, Volt-Var control, etc. Note that the outside refers to the distributed energy resource management device 1, the VPP aggregator system 2, the power distribution automation system 3, etc.

[0020] In maximum output power control, the maximum output values of active power and reactive power are commanded from the outside as set values, and the smart inverter operates to maintain the states where the active power and reactive power output to the power distribution system are below the set values (maximum output values). In Volt-Var control, the target value of the terminal voltage of the smart inverter and the dead band which is the range where no control is performed are commanded from the outside as set values, and when the terminal voltage of the smart inverter is outside the range indicated by the dead band, the smart inverter adjusts the output of reactive power so that the terminal voltage approaches the target value. Note that the target value is included in the dead band. For example, the smart inverter is commanded from the outside so that the vicinity of the median value of the dead band becomes the target value.

[0021] Next, the configurations and operations of the distributed energy resource management device 1, the VPP aggregator system 2, and the distribution automation system 3 of the distributed energy resource management system 100 will be described in detail.

[0022] FIG. 2 is a diagram showing a configuration example of the distributed energy resource management device 1 according to Embodiment 1. As shown in FIG. 2, the distributed energy resource management device 1 includes an information acquisition unit 11, a solar power generation output prediction unit 12, an optimal power flow calculation unit 13, a set value calculation unit 14, a control information output unit 15, a storage unit 16, and a communication unit 17.

[0023] The information acquisition unit 11 acquires, through the communication unit 17, management device information which is information about DERs managed by the VPP aggregator system 2, and management object information which is information about DERs, SVRs, power distribution systems, etc. managed by the distribution automation system 3. The management device information and the management object information include information necessary when the distributed energy resource management device 1 controls the DERs, information necessary when the distributed energy resource management device 1 determines the setting values to be commanded to the DERs, and the like. For example, the information acquisition unit 11 acquires, from the VPP aggregator system 2 and the distribution automation system 3, information such as information on the controllable range of the DERs, information on the presence or absence of power factor constraints, information on the control method of the DERs, system information, and SVR information as management device information or management object information. Here, the controllable range of the DERs refers to the controllable range of the active power output by the smart inverter provided in the DER to the power distribution system, the controllable range of the reactive power, and the controllable range of the apparent power. The information on the presence or absence of power factor constraints is information indicating whether the DER has power factor constraints. Also, the information on the control method of the DERs is information indicating whether the control of the output power by the DER is in the form of a constant value control quantity command type or a control setting value command type.

[0024] The solar power generation output prediction unit 12 predicts the maximum output and the minimum output of the PV for the target time section. The target time section is, for example, a 30-minute section. The solar power generation output prediction unit 12 may perform machine learning using, for example, the past PV output performance and weather information, and perform prediction using the learned model generated by the machine learning, or may perform prediction by other methods. When configured to predict the maximum output and the minimum output of the PV using machine learning, for example, in the learning phase, the past PV output performance value and the weather information at the time when this performance was obtained are used as feature quantities, and the relationship between the PV output performance value and the weather at that time is learned to generate a learned model. The weather information used for machine learning may be acquired from the outside via the Internet or the like, or may be manually input by the user of the distributed energy resource management device 1. Also, in the utilization phase, the predicted values of the maximum output and the minimum output of the PV are calculated by inputting the weather forecast information of the target time section into the learned model. The feature quantity may be configured to include information on other conditions that affect the PV output in addition to the PV output performance value and the weather information. For example, information such as the date and time when the PV output performance value was obtained, the solar irradiance, solar intensity, solar altitude, voltage of the power distribution system, temperature, and humidity at the time when the PV output performance value was obtained may be added to the feature quantity.

[0025] Also, the solar power generation output prediction unit 12 may use the performance values of the PV maximum output and the minimum output at the same time section in the past determined period as the predicted values instead of performing prediction using machine learning. Also, the solar power generation output prediction unit 12 may estimate the maximum PV power generation amount from the solar altitude, the PV power generation capacity, etc. of the target time section. For example, the result of multiplying the PV power generation capacity by a coefficient (a value less than 1) corresponding to the solar altitude is used as the predicted value of the maximum output of the PV, and the predicted value of the minimum output is set to 0 kW, for example. Also, the solar power generation output prediction unit 12 may use the PV power generation capacity as the predicted value of the maximum output of the PV and set the predicted value of the minimum output to 0 kW.

[0026] For each of the conditions where the PV output is maximum and minimum, the optimal power flow calculation unit 13 determines the control amount of the DER that keeps the current and voltage within the defined appropriate ranges and minimizes the control cost through optimal power flow (OPF) calculation, which is a type of optimization calculation. The control cost is the cost required for control. Since the control cost varies for each DER, the optimal power flow calculation unit 13 derives through optimal power flow calculation which DER among the plurality of DERs can minimize the control cost while keeping the current and voltage within the appropriate ranges. Information such as the system information and predicted load information used in the optimal power flow calculation uses the corresponding information held in the storage unit 16. Here, the "condition where the PV output is maximum" means the state where the PV output is maximum, and the "condition where the PV output is minimum" means the state where the PV output is minimum. That is, the optimal power flow calculation unit 13 determines through optimal power flow calculation the control amount of the DER that keeps the current and voltage within the defined appropriate ranges and minimizes the control cost when the PV output is the maximum output predicted by the solar power generation output prediction unit 12. Also, the optimal power flow calculation unit 13 determines through optimal power flow calculation the control amount of the DER that keeps the current and voltage within the defined appropriate ranges and minimizes the control cost when the PV output is the minimum output predicted by the solar power generation output prediction unit 12. In this embodiment, it is decided to determine the control amount of the DER that keeps the current and voltage within the defined appropriate ranges and minimizes the control cost. However, instead of the control cost, the total control amount, suppression of solar power generation output, etc. may be used to determine the control amount of the DER that minimizes these. That is, the optimal power flow calculation unit 13 may determine the control amount of the DER that keeps the current and voltage within the defined appropriate ranges and minimizes the total control amount, or may determine the control amount of the DER that keeps the current and voltage within the defined appropriate ranges and minimizes the suppression of solar power generation output.

[0027] Regarding the control amount of DER, the control amount of active power and the control amount of reactive power with the same value may be obtained under the conditions where the PV output is maximum and minimum, respectively, or the control amount of active power and the control amount of reactive power may be obtained individually for each condition. Further, there may be a mixture of DERs with the same control amount under the conditions where the PV output is maximum and minimum, respectively, and DERs with different control amounts under the conditions where the PV output is maximum and minimum, respectively.

[0028] Generally, for DERs connected by a smart inverter, since the control amount can be autonomously controlled according to the grid state, it is formulated in the optimal power flow calculation as a control variable that takes different control amounts under the conditions where the PV output is maximum and minimum, respectively.

[0029] In addition, for other DERs, that is, DERs that cannot autonomously control the control amount according to the grid state, it is common to continue to output the power of the commanded control amount. Therefore, it is formulated in the optimal power flow calculation as a control variable that takes the same value under each of the conditions where the PV output is maximum and minimum.

[0030] An example of the operation in which the optimal power flow calculation unit 13 determines the control amount of DER by the optimal power flow calculation will be described. FIG. 3 is a diagram showing an example of the optimal power flow calculation performed by the optimal power flow calculation unit 13 of the distributed energy resource management device 1 according to Embodiment 1.

[0031] FIG. 3 shows an image of a case where control amounts for a storage battery having a Volt-Var control function and a PV having a maximum output limit control function are determined by optimal power flow calculation. For example, as shown in FIG. 3, consider performing optimal power flow calculation in a distribution system in which a storage battery that performs Volt-Var control and a PV that can limit its maximum output by maximum output limit control are interconnected. In the optimal power flow calculation in this case, the reactive power control amount of the storage battery and the active power control amount of the PV under the PV output maximum condition (when the PV output is the maximum output predicted by the solar power generation output prediction unit 12) and the PV output minimum condition (when the PV output is the minimum output predicted by the solar power generation output prediction unit 12) are used as variables. Under the PV output maximum condition and the PV output minimum condition, control amounts of each DER that satisfy each constraint and minimize the total control cost of each DER (in the example of FIG. 3, the control cost of the storage battery + the control cost of the PV) are determined. The constraints here are the upper limit of proper voltage and the lower limit of proper voltage. Note that in FIG. 3, the reactive power control amount of the storage battery under the PV output maximum condition is described as the "maximum section reactive power control amount", the reactive power control amount of the storage battery under the PV output minimum condition is described as the "minimum section reactive power control amount", and the active power control amount of the PV under the PV output maximum condition is described as the "maximum section active power control amount".

[0032] The optimal power flow calculation unit 13 determines, as the control amounts of the DERs for which the voltage distribution under the PV output maximum condition is equal to or lower than the upper limit of proper voltage, the active power control amount of the PV (the maximum cross-section active power control amount) and the reactive power control amount of the storage battery (the maximum cross-section reactive power control amount). Further, as the control amount of the DER for which the voltage distribution under the PV output minimum condition is equal to or higher than the lower limit of proper voltage, the reactive power control amount of the storage battery (the minimum cross-section reactive power control amount) is determined. By controlling the voltages and currents of the PV and the storage battery according to the control amounts determined by the optimal power flow calculation unit 13, when the power generation amount of the PV is large, the output power from the PV to the distribution system and the output power from the storage battery to the distribution system are limited, and the voltage distribution becomes as shown by the solid line, and a state equal to or lower than the upper limit of proper voltage can be maintained. Further, when the power generation amount of the PV is small, the output power from the storage battery to the distribution system increases, and the voltage distribution becomes as shown by the solid line, and a state equal to or higher than the lower limit of proper voltage can be maintained. Note that when the voltages and currents of the PV and the storage battery are not controlled according to the control amounts determined by the optimal power flow calculation unit 13, the voltage distribution becomes as shown by the broken line, and when the power generation amount of the PV is large, the voltage distribution exceeds the upper limit of proper voltage, and when the power generation amount of the PV is small, the voltage distribution falls below the lower limit of proper voltage.

[0033] Note that the optimization logic used for the optimal power flow calculation in the optimal power flow calculation unit 13 is not limited. Any optimization logic may be used. Further, in FIG. 3, for the sake of simplification of the explanation, the SVR output voltage range, which is the range of the voltage output by the SVR, is fixed, but this may be made a variable, and the SVR output voltage range and the control amounts of the respective DERs may be determined according to the power generation amount of the PV. Further, although not described in FIG. 3, the output power value from a DER that outputs a constant active power or reactive power regardless of the output condition of the PV may also be used as a control variable. This DER is optimized as a variable (control amount) having the same value under both the condition where the PV output is maximum and the condition where it is minimum.

[0034] Based on the optimal power flow calculation results in the optimal power flow calculation unit 13, the setting value calculation unit 14 calculates setting values for the smart inverter included in the control setting value command type DER. For the smart inverter, there are many functions, but the setting value calculation unit 14 calculates setting values for the functions described above, namely, the function of controlling the output of reactive power so that the system voltage approaches the target voltage (the function of performing Volt-Var control), and the function of limiting the output of active power (the function of performing maximum output limit control).

[0035] An example of the operation of the setting value calculation unit 14 for calculating setting values will be described. FIG. 4 is a diagram showing a first example of setting value calculation performed by the setting value calculation unit 14 of the distributed energy resource management device 1 according to Embodiment 1.

[0036] FIG. 4 shows an image of calculating the setting value of a storage battery having a Volt-Var control function.

[0037] When determining the target voltage and deadband width of the Volt-Var control of the storage battery, the setting value calculation unit 14 can calculate from the voltage distribution obtained by the optimal power flow calculation under the conditions where the PV output is maximum and minimum as shown in FIG. 4. Specifically, the setting value calculation unit 14 obtains the voltage at the location where the storage battery is installed from the voltage distribution obtained by the optimal power flow calculation under the condition where the PV output is maximum, that is, the voltage at the location where the storage battery is installed when the PV output is maximum, and sets this voltage as the upper limit of the deadband. Similarly, the setting value calculation unit 14 obtains the voltage at the location where the storage battery is installed from the voltage distribution of the optimal power flow calculation result under the condition where the PV output is minimum, that is, the voltage at the location where the storage battery is installed when the PV output is minimum, and sets this voltage as the lower limit of the deadband.

[0038] Note that the battery commanded with the deadband monitors its own terminal voltage and, when the voltage deviates from the deadband, controls the output of reactive power so that the voltage enters the deadband. By setting the deadband in this way, even when the output of the PV varies and the voltage in the distribution system fluctuates, the voltage at the location where the battery is installed is controlled to be within the deadband derived by optimal power flow calculation, avoiding the deviation of the voltage in the distribution system from the appropriate range. Also, regarding the method for determining the gain used when determining the output amount of reactive power in Volt-Var control, it may be determined by any method such as existing methods.

[0039] Another example of the operation in which the setting value calculation unit 14 calculates the setting value will be described. FIG. 5 is a diagram showing a second example of the setting value calculation performed by the setting value calculation unit 14 of the distributed energy resource management device 1 according to Embodiment 1.

[0040] FIG. 5 shows an image of the case of calculating the setting value of the PV that can limit the maximum output by maximum output limit control.

[0041] When the setting value calculation unit 14 determines the maximum value of the PV output as the setting value of the PV that performs maximum output limit control, it derives the setting value by subtracting the active power control amount of the PV calculated by the above-described optimal power flow calculation from the maximum output of the PV predicted by the solar power generation output prediction unit 12 described above. For example, in the case where a current constraint violation occurs if the output of active power is not controlled, this logic makes it possible to limit the output of the PV up to the range that satisfies the current constraint. Note that the description regarding current is omitted in FIG. 5.

[0042] The control information output unit 15 notifies the control command value and the setting value to the VPP aggregator system 2 via the communication unit 17.

[0043] The storage unit 16 acquires and stores system information, past power generation records by power generation facilities such as PV, etc. from the distribution automation system 3 via the communication unit 17.

[0044] The communication unit 17 communicates with other devices having a communication function, such as the VPP aggregator system 2 and the distribution automation system 3.

[0045] Next, the configuration of the VPP aggregator system 2 will be described. FIG. 6 is a diagram showing a configuration example of the VPP aggregator system 2 according to the first embodiment. As shown in FIG. 6, the VPP aggregator system 2 includes a management device information output unit 21, a storage unit 22, a device control unit 23, and a communication unit 24.

[0046] The management device information output unit 21 transmits, as management device information, information regarding the DERs managed by the VPP aggregator system 2 among the various information held by the storage unit 22, which is used in processes such as PV output prediction and optimal power flow calculation in the distributed energy resource management device 1, to the distributed energy resource management device 1 via the communication unit 24. The management device information output unit 21 transmits the management device information to the distributed energy resource management device 1, for example, when a preset time or timing (once a day, every 30 minutes, etc.) is reached. The management device information output unit 21 may notify the management device information when requested by the distributed energy resource management device 1.

[0047] The storage unit 22 stores information regarding the DERs managed by the VPP aggregator system 2. Examples of information regarding the DERs include the identification information of the DERs, the types of DERs, the installation locations of the DERs, the operating states of the DERs, the controllable ranges of the DERs, the functions of the DERs, the control methods of the DERs, the generation capacity and actual generated energy values when the DERs are PVs, and the like.

[0048] The device control unit 23 controls the DERs by transmitting commands to the DERs to be managed via the communication unit 24. The commands transmitted by the device control unit 23 to the DERs also include commands for the DERs generated by the distributed energy resource management device 1. In addition, the device control unit 23 acquires information such as the operating state and actual generated energy value from the DERs and stores it in the storage unit 22.

[0049] The communication unit 24 communicates with other devices having a communication function, such as the distributed energy resource management device 1 and DERs.

[0050] Next, the configuration of the distribution automation system 3 will be described. FIG. 7 is a diagram showing a configuration example of the distribution automation system 3 according to the first embodiment. As shown in FIG. 7, the distribution automation system 3 includes a management object information output unit 31, a storage unit 32, a distribution system control unit 33, and a communication unit 34.

[0051] The management object information output unit 31 transmits, as management object information, information regarding devices (such as DERs and SVRs) managed by the distribution automation system 3 among various information held by the storage unit 32, which is used in processes such as PV output prediction and optimal power flow calculation in the distributed energy resource management device 1, to the distributed energy resource management device 1 via the communication unit 34. The management object information output unit 31 transmits the management object information to the distributed energy resource management device 1, for example, when a preset time or timing (once a day, every 30 minutes, etc.) is reached. The management object information output unit 31 may notify the management object information when requested by the distributed energy resource management device 1.

[0052] The storage unit 32 stores information regarding devices managed by the distribution automation system 3 and distribution system information. Examples of information regarding devices include device identification information, device type, device installation location, device operating status, functions of the device, controllable range when the device is a DER, control method when the device is a DER, actual values of power generation capacity and power generation amount when the device is a PV, and the like.

[0053] The power distribution system control unit 33 controls various devices constituting the power distribution system. For example, the power distribution system control unit 33 controls the DER by transmitting commands to the DER to be managed via the communication unit 34. The commands transmitted by the power distribution system control unit 33 to the DER also include commands for the DER generated by the distributed energy resource management device 1. In addition, the power distribution system control unit 33 acquires information such as the operating state and the actual power generation amount from the DER and stores it in the storage unit 32. Further, the power distribution system control unit 33 controls the SVR.

[0054] The communication unit 34 communicates with other devices having a communication function, such as the distributed energy resource management device 1 and the DER.

[0055] Next, the operation of the distributed energy resource management device 1 controlling the DER connected to the power distribution system via the VPP aggregator system 2 and the distribution automation system 3 will be described with reference to a flowchart.

[0056] FIG. 8 is a flowchart showing an example of the operation of the distributed energy resource management device 1 according to Embodiment 1 for controlling the DER.

[0057] As shown in FIG. 8, in the distributed energy resource management device 1, first, the information acquisition unit 11 acquires management device information from the VPP aggregator system 2 and acquires management object information from the distribution automation system 3 (step S11).

[0058] Next, the photovoltaic power generation output prediction unit 12 predicts the maximum output value and the minimum output value of the PV connected to the power distribution system (step S12). In this step S12, the photovoltaic power generation output prediction unit 12 predicts, for each PV, the maximum value and the minimum value of the active power output to the power distribution system and the maximum value and the minimum value of the reactive power output to the power distribution system at the target time section. The photovoltaic power generation output prediction unit 12 performs the prediction using the management device information and the management object information acquired by the information acquisition unit 11.

[0059] Next, the optimal power flow calculation unit 13 determines the DER control amounts that satisfy the system constraints and minimize the DER control cost for the cases of maximum and minimum PV outputs (step S13). The system constraints are, for example, the current constraints and voltage constraints of the distribution system. Specifically, the current constraints are, for example, the maximum value of the current flowing through the distribution system, and the voltage constraints are, for example, the upper and lower limit values of the voltage of the distribution system. In step S13, the optimal power flow calculation unit 13 performs an optimal power flow calculation using the management device information and the management object information acquired by the information acquisition unit 11, and the maximum and minimum values of the PV output predicted by the solar power generation output prediction unit 12, and individually determines the control amounts of each DER to be controlled. The control amount of the DER is the value of the active power and reactive power output by the DER to the distribution system.

[0060] Next, the setting value calculation unit 14 determines the setting values of the smart inverters provided in each DER based on the results of the optimal power flow calculation by the optimal power flow calculation unit 13 (step S14). In this step S14, the setting value calculation unit 14 determines the setting values according to the control methods applied to each DER to be controlled. As described above, for example, for a DER that performs Volt-Var control, the setting value calculation unit 14 determines the target value of the terminal voltage and the deadband width. For a DER that performs maximum output limit control, the setting value calculation unit 14 determines the maximum output values of the active power and reactive power.

[0061] Finally, the control information output unit 15 outputs either or both of the active power control command and the reactive power control command and the set value (step S15), and the communication unit 17 transmits these to the VPP aggregator system 2 and the distribution automation system 3. The active power control command and the reactive power control command are commands for the DER control amount determined by the optimal power flow calculation unit 13 performing optimal power flow calculation in step S13 above. Also, the set value is the set value determined by the set value calculation unit 14 in step S14 above. In step S15, the control information output unit 15 outputs the active power control command and the reactive power control command to the DER configured to operate according to the active power and reactive power control commands received from the outside. Also, the control information output unit 15 outputs the set value to the DER configured to perform local control.

[0062] Here, the hardware configuration of the distributed energy resource management device 1 will be described. The distributed energy resource management device 1 is a distributed energy resource management program, which is a program in which the processing in the distributed energy resource management device 1 is described, is executed on a computer system, whereby the computer system functions as the distributed energy resource management device 1. FIG. 9 is a diagram showing a configuration example of a computer system that realizes the distributed energy resource management device 1. As shown in FIG. 9, this computer system includes a control unit 101, an input unit 102, a storage unit 103, a display unit 104, a communication unit 105, and an output unit 106, which are connected via a system bus 107.

[0063] In FIG. 9, the control unit 101 is a processor such as a CPU (Central Processing Unit), and executes the above-described distributed energy resource management program. The input unit 102 is composed of, for example, a keyboard, a mouse, etc., and is used by the user of the computer system to input various kinds of information. The storage unit 103 includes various memories such as RAM (Random Access Memory) and ROM (Read Only Memory), and storage devices such as hard disks, and stores the distributed energy resource management program executed by the control unit 101, necessary data obtained during the process of processing, etc. Also, the storage unit 103 is used as a temporary storage area for programs. The display unit 104 is composed of a display, an LCD (Liquid Crystal Display Panel), etc., and displays various screens to the user of the computer system. The communication unit 105 is a receiver and a transmitter that perform communication processing. The output unit 106 is a printer, etc. Note that FIG. 9 is an example, and the configuration of the computer system is not limited to the example of FIG. 9.

[0064] An operation example of the computer system until the distributed energy resource management program becomes executable will be described. In the computer system having the above-described configuration, for example, the distributed energy resource management program is installed in the storage unit 103 from a CD-ROM or a DVD-ROM set in a CD (Compact Disc)-ROM drive or a DVD (Digital Versatile Disc)-ROM drive (not shown). Then, when the distributed energy resource management program is executed, the distributed energy resource management program read from the storage unit 103 is stored in the storage unit 103. In this state, the control unit 101 executes processing as the distributed energy resource management device 1 according to the program stored in the storage unit 103.

[0065] In the above description, a distributed energy resource management program that describes the processing in the distributed energy resource management device 1 is provided with a CD-ROM or a DVD-ROM as a recording medium. However, the present invention is not limited to this, and depending on the configuration of the computer system, the capacity of the distributed energy resource management program to be provided, etc., for example, a distributed energy resource management program provided by a transmission medium such as the Internet via the communication unit 105 may be used.

[0066] As described above, in the distributed energy resource management system 100 according to the present embodiment, the distributed energy resource management device 1 acquires management device information, which is information related to DER, from the VPP aggregator system 2 that manages and controls DER, and also from the distribution automation system 3 that manages and controls devices such as DER and SVR installed by power utilities, etc., information related to devices such as DER and SVR and management object information, which is information related to the distribution system. Based on the acquired information, the maximum and minimum values of the PV output connected to the distribution system are predicted. The distributed energy resource management device 1 further performs an optimal power flow calculation using the prediction results of the maximum and minimum values of the PV output, the management device information, and the management object information, determines the control amount of the DER that satisfies the constraints of the distribution system and minimizes the control cost of the DER, and determines the setting value of the smart inverter provided in the DER. Thereby, the distributed energy resource management device 1 according to the present embodiment can maintain the voltage of the transmission and distribution system within an appropriate range even when the power generation amount of the PV connected to the distribution system changes and the amount of power output from the PV to the distribution system fluctuates.

[0067] Note that the distributed energy resource management device 1 of the present embodiment is configured to notify the control amount of the DER and the setting value of the smart inverter, which are determined by performing optimal power flow calculation, to the PV or the like to be controlled via the VPP aggregator system 2 or the distribution automation system 3, but the present invention is not limited to this configuration. For example, as in the distributed energy resource management system 100a shown in FIG. 10, a configuration may be adopted in which a distributed energy resource management device 1a capable of directly notifying a control command indicating a power control amount and a setting value to DERs (PV 51, EV charger 52, system battery 53) and an SVR 4 connected to the distribution system is provided. The distributed energy resource management device 1a is the same as the above-described distributed energy resource management device 1 except that it can directly transmit a control command and a setting value to devices such as DERs and SVRs. FIG. 10 is a diagram showing another configuration example of the distributed energy resource management system according to Embodiment 1.

[0068] Also, a part of the processing executed by the distributed energy resource management device 1 described in the present embodiment may be executed by another device, for example, the VPP aggregator system 2 or the distribution automation system 3. For example, a configuration may be adopted in which the distribution automation system 3 performs the process of determining the setting value by the above-described setting value calculation unit 14. In this case, after the optimal power flow calculation unit 13 of the distributed energy resource management device 1 performs the optimal power flow calculation, the distributed energy resource management device 1 notifies at least the control amount of the DER among the information generated by the optimal power flow calculation to the distribution automation system 3. The distribution automation system 3 calculates the voltage and current distribution from the notified control amount of the DER, and determines the setting value of the smart inverter provided in each DER based on the result.

[0069] Also, in this embodiment, the distributed energy resource management device 1 individually determines the power control amount and the set value for each DER managed by the VPP aggregator system 2 and notifies each DER. However, it is not limited to such a control method. The distributed energy resource management device 1 may aggregate a plurality of DERs and determine the power control amount for these plurality of DERs. In this case, the VPP aggregator system 2 determines the power control amount for each of the plurality of DERs based on the power control amount for the plurality of DERs determined by the distributed energy resource management device 1. For example, the distributed energy resource management device 1 aggregates DER#1, DER#2, and DER#3, determines the total power control amount for these three DERs, and notifies the VPP aggregator system 2. The VPP aggregator system 2 determines the power control amount for each of DER#1, DER#2, and DER#3 based on the power control amount notified from the distributed energy resource management device 1. Specifically, the VPP aggregator system 2 determines the power control amount for DER#1, DER#2, and DER#3 such that the sum of the power control amounts for DER#1, DER#2, and DER#3 respectively matches the power control amount notified from the distributed energy resource management device 1. The unit by which the distributed energy resource management device 1 aggregates a plurality of DERs is, for example, the section between two adjacent switches. That is, the distributed energy resource management device 1 determines the total value of the power control amounts of each DER existing between two adjacent switches and notifies the determined total value to the VPP aggregator system 2.

[0070] Embodiment 2. FIG. 11 is a diagram showing a configuration example of the distributed energy resource management system 100b according to Embodiment 2.

[0071] As shown in FIG. 11, the distributed energy resource management system 100b includes a distributed energy resource management device 1b, a VPP aggregator system 2, a distribution automation system 3, and a solar power generation amount prediction system 6. The distributed energy resource management system 100b has a configuration in which the solar power generation amount prediction system 6 is added to the distributed energy resource management system 100 according to Embodiment 1, and the distributed energy resource management device 1 is replaced with the distributed energy resource management device 1b. In this embodiment, descriptions of the VPP aggregator system 2 and the distribution automation system 3 common to the distributed energy resource management system 100 according to Embodiment 1 are omitted.

[0072] FIG. 12 is a diagram showing a configuration example of the distributed energy resource management device 1b according to Embodiment 2. As shown in FIG. 2, the distributed energy resource management device 1b includes an information acquisition unit 11, an optimal power flow calculation unit 13, a setting value calculation unit 14, a control information output unit 15, a storage unit 16, and a communication unit 17. That is, the distributed energy resource management device 1b has a configuration in which the solar power generation output prediction unit 12 is deleted from the distributed energy resource management device 1 according to Embodiment 1. The information acquisition unit 11, the optimal power flow calculation unit 13, the setting value calculation unit 14, the control information output unit 15, the storage unit 16, and the communication unit 17 of the distributed energy resource management device 1b are the same as the components with the same reference numerals of the distributed energy resource management device 1 according to Embodiment 1. Therefore, descriptions of these components are omitted.

[0073] In the distributed energy resource management system 100b, the solar power generation output prediction system 6 performs the prediction of the PV output that is carried out by the solar power generation output prediction unit 12 of the distributed energy resource management device 1 according to Embodiment 1. The distributed energy resource management system 100b acquires the maximum output and the minimum output of the PV predicted by the solar power generation output prediction system 6 from the solar power generation output prediction system 6, and stores them in the storage unit 16. The optimal power flow calculation unit 13 performs the optimal power flow calculation using the prediction results of the maximum output and the minimum output of the PV stored in the storage unit 16. Note that the information acquisition unit 11 acquires the maximum output and the minimum output of the PV predicted by the solar power generation output prediction system 6.

[0074] FIG. 13 is a diagram showing a configuration example of the solar power generation output prediction system 6 that constitutes the distributed energy resource management system 100b according to Embodiment 2. As shown in FIG. 13, the solar power generation output prediction system 6 includes an information collection unit 61, a storage unit 62, a solar power generation output prediction unit 63, a prediction result output unit 64, and a communication unit 65.

[0075] The information collection unit 61 collects information used when the solar power generation output prediction unit 63, which will be described later, predicts the maximum output and the minimum output of the PV at the target time section. The information collection unit 61 collects information that affects the output of the PV, such as, for example, the past performance of the PV output, the predicted weather at the target time section, and the altitude of the sun at the target time section.

[0076] The storage unit 62 stores various information, such as the information collected by the information collection unit 61, the prediction results of the maximum output and the minimum output of the PV by the solar power generation output prediction unit 63, and the like.

[0077] The photovoltaic power generation output prediction unit 63 predicts the maximum output and the minimum output of the PV at the target time section based on the information collected by the information collection unit 61. The photovoltaic power generation output prediction unit 63 predicts the maximum output and the minimum output of the PV at the target time section, for example, in a manner similar to the method by which the photovoltaic power generation output prediction unit 12 of the distributed energy resource management device 1 according to the first embodiment predicts the maximum output and the minimum output of the PV at the target time section. Note that the photovoltaic power generation output prediction unit 63 may perform prediction by a method different from that of the photovoltaic power generation output prediction unit 12 of the distributed energy resource management device 1 according to the first embodiment.

[0078] The prediction result output unit 64 notifies the distributed energy resource management device 1b of the maximum output and the minimum output of the PV at the target time section predicted by the photovoltaic power generation output prediction unit 63 via the communication unit 65.

[0079] The communication unit 65 communicates with other devices having a communication function such as the distributed energy resource management device 1b.

[0080] As described above, the distributed energy resource management system 100b according to the present embodiment includes a photovoltaic power generation amount prediction system 6 that predicts the maximum output and the minimum output of the PV at the target time section. The distributed energy resource management device 1b performs an optimal power flow calculation using the prediction results of the photovoltaic power generation amount prediction system 6, and determines the control amount of the DER and the setting values of the smart inverters included in the DER. The distributed energy resource management system 100b according to the present embodiment can obtain the same effects as the distributed energy resource management system 100 according to the first embodiment.

[0081] The configurations shown in the above embodiments are merely examples, and it is possible to combine them with other known technologies, combine the embodiments with each other, and omit or change a part of the configuration without departing from the gist.

Explanation of Reference Numerals

[0082] 1, 1a, 1b Distributed energy resource management device, 2 VPP aggregator system, 3 Distribution automation system, 4 SVR, 6 Solar power generation prediction system, 11 Information acquisition unit, 12, 63 Solar power generation output prediction unit, 13 Optimal power flow calculation unit, 14 Setting value calculation unit, 15 Control information output unit, 16, 22, 32, 62 Memory unit, 17, 24, 34, 65 Communication unit, 21 Management device information output unit, 23 Device control unit, 31 Management target information output unit, 33 Distribution system control unit, 51 Solar power generation equipment (PV), 52 EV charger, 53 System battery, 54 Home EV charger, 55 Home battery, 61 Information collection unit, 64 Prediction result output unit, 100, 100a, 100b Distributed energy resource management system.

Claims

1. An information acquisition unit that acquires information on distributed energy resources connected to a power distribution system and information on the power distribution system; A photovoltaic power generation output prediction unit that predicts the maximum output value and the minimum output value of photovoltaic power generation included in the distributed energy resources connected to the power distribution system; Using the information acquired by the information acquisition unit, the maximum output value predicted by the photovoltaic power generation output prediction unit, and the minimum output value, perform optimal power flow calculations under the maximum output condition where the output of the photovoltaic power generation reaches the maximum output value and under the minimum output condition where the output of the photovoltaic power generation reaches the minimum output value, and an optimal power flow calculation unit that determines the control amount of the distributed energy resources connected to the power distribution system for each of the maximum output condition and the minimum output condition; A setting value calculation unit that determines the setting value of the distributed energy resources for each of the maximum output condition and the minimum output condition based on the voltage distribution of the power distribution system obtained by the optimal power flow calculation; A control information output unit that notifies the distributed energy resources of the control amount determined by the optimal power flow calculation unit and the setting value determined by the setting value calculation unit; A distributed energy resource management device, characterized by comprising the above.

2. The information on the distributed energy resources acquired by the information acquisition unit includes the controllable range of the output power from the distributed energy resources to the power distribution system and information on the control method of the output power from the distributed energy resources to the power distribution system. The distributed energy resource management device according to claim 1, characterized by the above.

3. The information on the power distribution system acquired by the information acquisition unit includes information indicating the topology of the power distribution system, the impedance of each distribution line constituting the power distribution system, and the position information of the voltage regulators installed in the power distribution system. The distributed energy resource management device according to claim 1 or 2, characterized by the above.

4. The upper limit of the output power from the distributed energy resources to the power distribution system is set as the setting value under the maximum output condition. The distributed energy resource management device according to any one of claims 1 to 3, characterized by the above.

5. The setting value calculation unit determines the upper limit of the output power based on the maximum output value predicted by the solar power generation output prediction unit and the control amount of the active power included in the control amount under the maximum output condition determined by the optimal power flow calculation unit. The distributed energy resource management device according to claim 4, characterized in that.

6. Using, as the setting value, the target value of the output voltage from the distributed energy resource to the power distribution system and the dead zone which is a range where the distributed energy resource does not control the power output to the power distribution system. The distributed energy resource management device according to any one of claims 1 to 3, characterized in that.

7. The setting value calculation unit determines the upper limit of the dead zone based on the voltage distribution when the output of the solar power generation is maximum and the position information of the location where the distributed energy resource is installed, and determines the lower limit of the dead zone based on the voltage distribution when the output of the solar power generation is minimum and the position information of the location where the distributed energy resource is installed. The distributed energy resource management device according to claim 6, characterized in that.

8. A virtual substation aggregator system that manages and controls distributed energy resources installed at consumers, A distribution automation system that manages and controls distributed energy resources connected to the power distribution system and equipment installed in the power distribution system in order to maintain the proper state of the power distribution system, A distributed energy resource management device that integrally manages the distributed energy resources managed by the virtual substation aggregator system and the distributed energy resources managed by the distribution automation system, Comprising, The distributed energy resource management device is, An information acquisition unit that acquires information on the distributed energy resources managed by the virtual substation aggregator system, information on the distributed energy resources managed by the distribution automation system, and information on the power distribution system from the virtual substation aggregator system and the distribution automation system, A solar power generation output prediction unit that predicts the maximum and minimum output values of solar power generation included in the distributed energy resources. Using the information acquired by the information acquisition unit, the maximum output value and the minimum output value predicted by the photovoltaic power generation output prediction unit, perform optimal power flow calculations under the maximum output condition where the output of the photovoltaic power generation reaches the maximum output value and the optimal power flow calculation under the minimum output condition where the output of the photovoltaic power generation reaches the minimum output value, and an optimal power flow calculation unit that determines the control amount of the distributed energy resource connected to the power distribution system for each of the maximum output condition and the minimum output condition; A setting value calculation unit that determines the setting value of the distributed energy resource for each of the maximum output condition and the minimum output condition based on the voltage distribution of the power distribution system obtained by the optimal power flow calculation; A control information output unit that notifies the distributed energy resource of the control amount determined by the optimal power flow calculation unit and the setting value determined by the setting value calculation unit; A distributed energy resource management system characterized by comprising the above.

9. The control information output unit notifies, via the virtual substation aggregator system, the control amount determined by the optimal power flow calculation unit and the setting value determined by the setting value calculation unit for the distributed energy resource managed by the virtual substation aggregator system, and notifies, via the distribution automation system, the control amount determined by the optimal power flow calculation unit and the setting value determined by the setting value calculation unit for the distributed energy resource managed by the distribution automation system. The distributed energy resource management system according to claim 8, characterized by the above.

10. The control information output unit directly notifies the distributed energy resource of the control amount determined by the optimal power flow calculation unit and the setting value determined by the setting value calculation unit. The distributed energy resource management system according to claim 8, characterized by the above.

11. A virtual substation aggregator system that manages and controls distributed energy resources installed at customers; A distribution automation system that manages and controls distributed energy resources connected to the power distribution system and equipment installed in the power distribution system to maintain the proper state of the power distribution system; A photovoltaic power generation amount prediction system that predicts the maximum output value and the minimum output value of the photovoltaic power generation included in the distributed energy resource; A distributed energy resource management device that integrally manages the distributed energy resources managed by the virtual substation aggregator system and the distributed energy resources managed by the distribution automation system, comprising: The distributed energy resource management device acquires information on the distributed energy resources managed by the virtual substation aggregator system, information on the distributed energy resources managed by the distribution automation system, and information on the distribution system from the virtual substation aggregator system and the distribution automation system, and acquires from the solar power generation amount prediction system the maximum output value and the minimum output value predicted by the solar power generation amount prediction system; an information acquisition unit; Using the information acquired by the information acquisition unit and the maximum output value and the minimum output value predicted by the solar power generation amount prediction system, perform optimal power flow calculations under the maximum output condition where the output of the solar power generation is the maximum output value and under the minimum output condition where the output of the solar power generation is the minimum output value, and determine the control amount of the distributed energy resources connected to the distribution system for each of the maximum output condition and the minimum output condition; an optimal power flow calculation unit; Based on the voltage distribution of the distribution system obtained by the optimal power flow calculation, determine the setting values of the distributed energy resources for each of the maximum output condition and the minimum output condition; a setting value calculation unit; A control information output unit that notifies the distributed energy resources of the control amount determined by the optimal power flow calculation unit and the setting value determined by the setting value calculation unit; A distributed energy resource management system, characterized by comprising the above.

12. An information acquisition step of acquiring information on the distributed energy resources connected to the distribution system and information on the distribution system; A solar power generation output prediction step of predicting the maximum output value and the minimum output value of the solar power generation included in the distributed energy resources connected to the distribution system; Using the information acquired in the information acquisition step and the maximum output value and the minimum output value predicted in the photovoltaic power generation output prediction step, perform optimal power flow calculations under the maximum output condition where the output of the photovoltaic power generation becomes the maximum output value and under the minimum output condition where the output of the photovoltaic power generation becomes the minimum output value, and determine the control amount of the distributed energy resource connected to the distribution system for each of the maximum output condition and the minimum output condition; an optimal power flow calculation step Based on the voltage distribution of the distribution system obtained by the optimal power flow calculation, a setting value determination step of determining the setting value of the distributed energy resource for each of the maximum output condition and the minimum output condition A control information output step of notifying the distributed energy resource of the control amount determined in the optimal power flow calculation step and the setting value determined in the setting value determination step A distributed energy resource management program characterized by causing a computer system to execute

Images