Charge-discharge plan creation apparatus and charge-discharge plan creation method

Abstract

To provide a charge / discharge plan preparation device capable of suitably preparing a charge / discharge plan of a storage battery from the viewpoint of power value improvement.SOLUTION: A power price information processing unit configured to generate deemed power procurement price data serving as a reference when allocating a charging and discharging operation by correcting a power price prediction value in a unit time section in which a power generation amount prediction value exceeds a demand prediction value according to a difference between a chargeable capacity of a storage battery and a power generation amount prediction value, the storage battery being connected to a RE power generation device; The charge / discharge planning unit creates the main charge / discharge plan as the charge / discharge plan by assigning the discharge operation preferentially from the unit time segment having a high deemed power procurement price and assigning the charge operation preferentially from the unit time segment having a low deemed power procurement price while pairing the unit time segment to which the charge / discharge operation is assigned and the unit time segment to which the discharge operation is assigned.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to the creation of a charge and discharge plan for a storage battery, and more particularly to the creation of a discharge plan for a storage battery that constitutes a microgrid together with a renewable energy power generation device and a load. [Background technology]

[0002] Storage batteries such as sodium-sulfur batteries (NaS batteries) are used as main components of power storage compensators for leveling power demand (load), emergency power supplies in the event of natural disasters, and for the purpose of monetizing by charging and discharging according to the price of electricity in the electricity market. For example, even for small-scale user systems such as general consumers, there is already known an electricity asset management system that aims to enable trading of self-generated electricity in accordance with fluctuations in market prices, and that is connected via a power grid to a user system equipped with a power generation facility that generates electricity, and that includes an electricity storage facility that stores electricity on the power grid (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-015468 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, due to recent trends such as the introduction of power microgrids and off-site PPAs, there has been an increase in facilities that combine equipment (RE power generation equipment) that generates electricity using renewable energy (RE) such as solar and wind power with energy storage equipment (storage batteries).

[0005] On the other hand, the spread of power generation using such renewable energy sources has led to an increase in the frequency of output curtailment due to the generation of surplus electricity, and has also given rise to problems such as the value of generated electricity becoming worthless and sudden price hikes in the electricity trading market.

[0006] From the perspective of preventing the occurrence of such problems and maximizing profits, it is necessary to make appropriate decisions regarding whether electricity generated using renewable energy should be sold to an external grid (reverse power flow), charged into a power storage facility, or consumed by consumers, as well as the timing of selling the electricity to an external grid and charging into a power storage facility.

[0007] However, with regard to energy storage facilities, although the vague concept of "storing electricity when the market value is low and releasing it when the market value is high" has been widely recognized, specific methodologies for addressing the above points have not necessarily been established.

[0008] For example, the following issues arise when outputting optimal charging and discharging patterns based on the state of the storage battery and information on electricity prices in the electricity market.

[0009] First, it is necessary to avoid situations where charging or discharging is physically impossible, such as when a charge command is issued even though the battery is fully charged, or when a discharge command is desirable due to high electricity market prices but the amount of charge is insufficient.

[0010] Second, it is difficult to create charging and discharging patterns that respond to complex price fluctuations or that cover long periods of time, making automation impossible.

[0011] Third, charge / discharge patterns that focus only on the market price of electricity are easy to create, since they basically involve discharging when the price is higher than the reference price and charging when it is lower. However, when power generation by renewable energy power generation equipment is taken into account, creating charge / discharge patterns becomes more complicated.

[0012] It should be noted that Patent Document 1 discusses how to manage generated power, but does not specifically mention how to control the power storage facility.

[0013] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a charge / discharge plan creation device that can create charge / discharge plans for storage batteries in an appropriate manner from the perspective of improving the value of electricity. [Means for solving the problem]

[0014] In order to solve the above problem, a first aspect of the present invention is an apparatus for creating, for each unit time segment, a charge and discharge plan for a predetermined planning period of a storage battery that constitutes, together with a renewable energy power generation device and a load, an electric power system connected to an external system that is an external commercial electric power system, the apparatus comprising: a RE power generation amount prediction unit that generates power generation amount prediction data describing a predicted value of the amount of power generated by the renewable energy power generation device for each unit time segment; a load demand prediction unit that generates load demand prediction data describing a predicted value of demand in the load for each unit time segment; an electric power price information processing unit that generates deemed power procurement price data describing a deemed power procurement price for each unit time segment that is used as a basis for allocating charging operations and discharging operations of the storage battery to each unit time segment; and a charge and discharge planning unit that creates the charge and discharge plan based on the deemed power procurement price data, the charge / discharge planning unit generates the deemed power procurement price data by acquiring from the outside power price forecast data describing a predicted value of the power price for each unit time interval when power is bought and sold between the power system and the external grid, acquiring the power generation forecast data and the load demand forecast data, and correcting the predicted value of the power price for each unit time interval in which the predicted value of power generation exceeds the predicted value of demand according to the difference between the chargeable capacity of the storage battery for each unit time interval and the predicted value of power generation; and the charge / discharge planning unit pairs the unit time interval to which the charging operation is assigned with the unit time interval to which the discharging operation is assigned, and allocates the discharging operation preferentially from the unit time interval in which the deemed power procurement price described in the deemed power procurement price data is high, and allocates the charging operation preferentially from the unit time interval in which the deemed power procurement price is low, thereby creating a main charge / discharge plan as the charge / discharge plan.

[0015] A second aspect of the present invention is a charge / discharge plan creation device according to the first aspect, characterized in that the charge / discharge planning unit determines whether or not at least one of the remaining capacity or temperature of the storage battery satisfies a predetermined constraint condition when the storage battery performs a charge / discharge operation in accordance with the main charge / discharge plan, and if it is determined that the constraint condition is not satisfied, changes the allocation, giving priority to units belonging to pairs with low profitability.

[0016] A third aspect of the present invention is the charge / discharge plan creation device according to the first or second aspect, wherein the charge / discharge planning unit is capable of creating a sub-charge / discharge plan selectively with or together with the main charge / discharge plan, and in the sub-charge / discharge plan, the power generated by the renewable energy power generation device is preferentially consumed by the load, and the surplus of the generated power is charged to the storage battery, and when the demand of the load cannot be met with the generated power alone, the power is supplied to the load by discharging from the storage battery, and when the demand cannot be met even by the discharging, power is purchased from the external system, and when the storage battery reaches the end of charging, the power is sold to the external system, and charging / discharging operations are allocated for each unit time segment so that:

[0017] A fourth aspect of the present invention is a charge / discharge plan creation device according to the third aspect, further comprising an adoption plan determination unit that, when the main charge / discharge plan and the secondary charge / discharge plan are both created, calculates a main plan revenue, which is the amount of revenue that will be obtained if the main charge / discharge plan is executed, and a secondary plan revenue, which is the amount of revenue that will be obtained if the secondary charge / discharge plan is executed, and determines the charge / discharge plan to be adopted for the operation of the storage battery based on the result of comparing the main plan revenue with the secondary plan revenue, and is characterized in that the adoption plan determination unit adopts the main charge / discharge plan if the main plan revenue is greater than or equal to the secondary plan revenue, and adopts the secondary charge / discharge plan if the secondary plan revenue is greater than the main plan revenue.

[0018] A fifth aspect of the present invention is a charge / discharge plan creation device according to the first aspect, characterized in that it further comprises a supply and demand forecast display processing unit that displays, on a predetermined display unit, a forecast graph of the trends in the demand for electricity and the amount of power generated if the charge / discharge plan is executed, based on the charge / discharge plan created in the charge / discharge planning unit, the power generation forecast data, and the load demand forecast data.

[0019] A sixth aspect of the present invention is a charge / discharge plan creation device according to the first aspect, characterized in that the power system is a microgrid including the renewable energy power generation device, the load, and the storage battery.

[0020] A seventh aspect of the present invention is a method for creating, for each unit time segment, a charge and discharge plan for a predetermined planning period for a storage battery that constitutes, together with a renewable energy power generation device and a load, a power system connected to an external system that is an external commercial power system, the method comprising: a) a step of generating power generation amount prediction data describing a predicted value of power generation amount in the renewable energy power generation device for each unit time segment; b) a step of generating load demand prediction data describing a predicted value of demand in the load for each unit time segment; c) a step of generating deemed power procurement price data describing a deemed power procurement price for each unit time segment that is used as a basis for allocating charging operations and discharging operations in the storage battery to each unit time segment; and d) a step of creating the charge and discharge plan based on the deemed power procurement price data, wherein in the step c), power is bought and sold between the power system and the external system. the step (d) obtains from the outside power price forecast data describing a predicted value of the power price for each unit time interval in a case where the predicted value of the power generation exceeds the predicted value of the demand, and obtains the power generation amount forecast data and the load demand forecast data, and generates the deemed power procurement price data by correcting the predicted value of the power price for each unit time interval in which the predicted value of the power generation exceeds the predicted value of the demand according to a difference between the chargeable capacity of the storage battery for each unit time interval and the predicted value of the power generation; and in the step (d), pairs the unit time interval to which the charging operation is assigned and the unit time interval to which the discharging operation is assigned, and allocates the discharging operation preferentially to the unit time interval in which the deemed power procurement price described in the deemed power procurement price data is high, and allocates the charging operation preferentially to the unit time interval in which the deemed power procurement price is low, thereby creating a main charge and discharge plan as the charge and discharge plan.

[0021] An eighth aspect of the present invention is a charge / discharge plan creation method according to the seventh aspect, characterized in that it further comprises the step of: e) determining whether or not at least one of the remaining capacity or temperature of the storage battery satisfies a predetermined constraint condition when the storage battery performs a charge / discharge operation in accordance with the main charge / discharge plan; and if it is determined that the constraint condition is not satisfied, changing the allocation, giving priority to units belonging to pairs with low profitability.

[0022] A ninth aspect of the present invention is the charge / discharge plan creation method according to the seventh or eighth aspect, wherein in d), a sub-charge / discharge plan can be created selectively with or together with the main charge / discharge plan, and in creating the sub-charge / discharge plan, charge / discharge operations are allocated for each of the unit time segments so that power generated by the renewable energy power generation device is consumed preferentially by the load, surplus power of the generated power is charged to the storage battery, and when the demand of the load cannot be met with the generated power alone, power is supplied to the load by discharging from the storage battery, when the demand cannot be met even by discharging, power is purchased from the external grid, and when the storage battery reaches the end of charging, power is sold to the external grid.

[0023] A tenth aspect of the present invention is a charge / discharge plan creation method according to the ninth aspect, further comprising: f) a step of calculating, when the main charge / discharge plan and the secondary charge / discharge plan are both created, a main plan profit, which is the amount of profit that will be obtained if the main charge / discharge plan is executed, and a secondary plan profit, which is the amount of profit that will be obtained if the secondary charge / discharge plan is executed, and determining a charge / discharge plan to be adopted for the operation of the storage battery based on a result of comparing the main plan profit with the secondary plan profit; wherein in step F), if the main plan profit is greater than or equal to the secondary plan profit, the main charge / discharge plan is adopted, and if the secondary plan profit is greater than the main plan profit, the secondary charge / discharge plan is adopted.

[0024] An eleventh aspect of the present invention is a charge / discharge plan creation method according to the seventh aspect, characterized in that the power system is a microgrid including the renewable energy power generation device, the load, and the storage battery. [Effects of the Invention]

[0025] According to the first to eleventh aspects of the present invention, a charge / discharge plan for a storage battery in a power system including a storage battery, a renewable energy power generation device, and a load can be created and executed based on a concept that emphasizes profits during charging and discharging.

[0026] In particular, according to the fourth and tenth aspects, it is possible to adopt and execute a charge / discharge plan that is expected to bring in a higher profit amount. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a schematic configuration diagram of a microgrid MG including an energy management system 1 that functions as a charge / discharge plan creation device. [Figure 2] FIG. 1 is a diagram showing functional components related to the creation of a charge / discharge plan, which are realized in the energy management system 1, together with the flow of data handled. [Figure 3] FIG. 10 is a diagram showing a flow for creating a main charge / discharge plan. [Figure 4] FIG. 10 is a diagram illustrating the generation of deemed electricity procurement price data DP1. [Figure 5] FIG. 10 is a diagram illustrating how to set a charging / discharging top. [Figure 6] FIG. 10 is a diagram illustrating how to set a charging / discharging top. [Figure 7] FIG. 10 is a diagram illustrating how to set a charging / discharging top. [Figure 8] FIG. 10 is a diagram illustrating how to set a charging / discharging top. [Figure 9] FIG. 10 is a graph showing a predicted transition of the amount of electricity demand and the amount of electricity generated. [Figure 10]1 is a schematic configuration diagram of the facilities of a power system 100 and a load system 200 when an off-site PPA is established. [Figure 11] 1 is a schematic configuration diagram of equipment of a power storage system 300. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0028] First Embodiment <Microgrid Overview> FIG. 1 is a schematic configuration diagram of a microgrid MG including an energy management system 1 that functions as a charge and discharge plan creation device in a first embodiment of the present invention.

[0029] The microgrid MG is a power system that mainly includes an energy management system 1, a storage battery 2, a renewable energy power generation device 3, and a load 4. The operations of the storage battery 2, the renewable energy power generation device 3, and the load 4 are controlled by respective control devices 2c, 3c, and 4c.

[0030] The energy management system 1 is generally a device that manages the exchange of power within the microgrid MG and the exchange of power between the microgrid MG and an external grid 5, which is a commercial power grid. Under the control of the energy management system 1, the microgrid MG is capable of connecting to the external grid 5 and exchanging power with the external grid 5, and is also capable of disconnecting from the external grid 5 and functioning as an independent grid that exchanges power within the microgrid MG.

[0031] The energy management system 1 is communicatively connected to the control devices 2c, 3c, and 4c, and not only gives each of the control devices 2c, 3c, and 4c control instructions for each of the control objects, but also acquires various status information (e.g., actual operating values ​​and fault information) for each of the control objects from each of the control devices 2c, 3c, and 4c.

[0032] The energy management system 1 also creates an implementation plan (charge and discharge pattern) for charging and discharging the storage battery 2 for a certain future period (planned period). As a result, in this embodiment, the energy management system 1 also functions as a charge and discharge plan creation device as described above. The planned period is, for example, the entire day of the day after the day the plan is created. In creating the charge and discharge implementation plan in this embodiment, one day of the planned period (0:00 to 24:00) is divided into 30-minute unit time segments also called "frames," and the charge and discharge operation of the storage battery 2 in each of the 48 frames is planned. The maximum amount of charge and discharge power in each frame is predetermined depending on the performance of the storage battery 2, etc.

[0033] The energy management system 1 is further connected to a power exchange 6 via a network (Internet) N. The power exchange 6 is a market that handles power transactions that take place in an external system 5 to which the microgrid MG is connected. The energy management system 1 acquires the predicted value of the power price announced by the power exchange 6 via the network N and uses it to create a charging and discharging plan. An example of the power exchange 6 is JEPX (Japan Electric Power Exchange, a general incorporated association).

[0034] The energy management system 1 and the control devices 2c, 3c, and 4c are each realized by a general-purpose or dedicated computer that includes a CPU, ROM, RAM, an input unit including a keyboard, a mouse, etc., a display unit including a display, a storage unit including a hard disk, etc., and a communication unit including an interface for communicating with the outside world via the network N, all of which are not shown. In each computer, a predetermined operating program stored in the ROM or RAM is executed by the CPU, causing the computer to function as the energy management system 1 and the control devices 2c, 3c, and 4c.

[0035] The storage battery 2 performs charging and discharging operations under the control of the control device 2c. The storage battery 2 is, for example, a sodium-sulfur battery (NaS battery), which is a high-temperature operating secondary battery. In one exemplary embodiment, the NaS battery is configured as a module battery in which a battery assembly made up of multiple single cells, each of which uses sulfur as a positive electrode active material and metallic sodium as a negative electrode active material, is housed in a housing.

[0036] The renewable energy power generation device 3 generates power under the control of the control device 3c. The renewable energy power generation device 3 is a solar power generation device, a wind power generation device, a biomass power generation device, etc. For simplicity of illustration, only one renewable energy power generation device 3 is shown in Fig. 1, but a single microgrid MG may be provided with a plurality of renewable energy power generation devices 3 regardless of type.

[0037] The load 4 is an electrical facility that consumes power. Note that, for simplicity of illustration, only one load 4 is shown in FIG. 1 , but a plurality of loads 4 may be provided in one microgrid MG. Furthermore, in this embodiment, it is assumed that the control device 4c controls the operation of the load 4 based on a control instruction from the energy management system 1, and that status information of the load 4 is provided from the control device 4c to the energy management system 1. However, depending on the type of load 4, there may be cases where the control device 4c is not provided, the control device 4c is not capable of communicating with the energy management system 1, or it may be possible to only obtain status information from the control device 4c.

[0038] The storage battery 2, the renewable energy power generation device 3, and the load 4 are electrically connected to one another and to an external system 5. This allows the storage battery 2 to be charged from the renewable energy power generation device 3, supply power to the load 4, and also to be charged and discharged (sold and bought) with the external system 5. Furthermore, the renewable energy power generation device 3 allows the generated power to be charged to the storage battery 2, supply power to the load 4, and also to be discharged (sold) to the external system 5. Furthermore, the load 4 can be supplied with power from the storage battery 2, the renewable energy power generation device 3, and the external system 5.

[0039] <Energy management system> FIG. 2 is a diagram showing functional components related to the creation of a charge / discharge plan, which are realized in the energy management system 1, together with the flow of data handled.

[0040] A predetermined operating program stored in ROM or RAM of a computer constituting the energy management system 1 is executed by a CPU, and the energy management system 1 mainly includes, as functional components, a load demand prediction unit 11, an RE power generation prediction unit 12, an electricity price information processing unit 13, a charge / discharge planning unit 14, and an adoption plan determination unit 15. Furthermore, a supply / demand forecast display processing unit 16 may be provided.

[0041] The load demand forecasting unit 11 forecasts the time change in the power demand of the load 4 during the planning period on a frame-by-frame basis, and generates load demand forecast data DD describing the forecast values. Such power demand forecasting is performed based on, for example, information such as the past actual power demand values ​​(and trends of time change) of the load 4, the operating environment of the load 4 expected on the forecast target date (weather, temperature, location, operating frequency, surrounding conditions, etc.), and the operating purpose of the load 4, which are acquired over time by the energy management system 1 via the control device 4c or by input by an operator or in other ways, and stored in a storage unit (not shown). Various conventionally known methods can be applied to such demand forecasting.

[0042] The RE power generation amount prediction unit 12 predicts, on a frame-by-frame basis, the change over time in the amount of power generated (RE power generation amount) in the renewable energy power generation device 3 during the planning period, and generates power generation amount prediction data DE describing the predicted values. The prediction of the RE power generation amount is performed based on, for example, past actual values ​​of RE power generation amount (and also the trend of change over time) that the energy management system 1 acquires over time via the control device 3c and stores in a storage unit (not shown), information on the operating environment of the renewable energy power generation device 3 expected on the prediction target date (weather, temperature, location, operating frequency, surrounding conditions, etc.), the operating purpose of the renewable energy power generation device 3, and the like. Various conventionally known methods can also be applied to the prediction of the RE power generation amount.

[0043] The power price information processing unit 13 acquires predicted data of time-varying power prices in the planning period predicted by the power exchange 6 as power price prediction data DP0. The power price prediction data DP0 describes a predicted value (predicted price) of the power price for each time period (unit time segment). The predicted price is a predicted value of the power price that is applied when buying and selling power between each device of the microgrid MG and the external grid 5.

[0044] Then, the electricity price information processing unit 13 generates deemed electricity procurement price data DP1 based on the electricity price prediction data DP0, the load demand prediction data DD generated by the load demand prediction unit 11, and the power generation amount prediction data DE generated by the RE power generation amount prediction unit 12.

[0045] The deemed electricity procurement price data DP1 is data generated based on the idea that if there is a time period during the planning period when the amount of electricity generated by the renewable energy power generation device 3 exceeds the amount of demand in the load 4, the procurement cost of charging the storage battery 2 with the surplus electricity obtained by subtracting the amount of demand in the load 4 from the amount of RE electricity generated can be ignored.

[0046] In this embodiment, the predicted price of electricity described in the power price prediction data DP0 is corrected according to the extent of such surplus generation and is referred to as the deemed power procurement price. The power price information processing unit 13 makes such corrections based on the contents of the power price prediction data DP0, and generates deemed power procurement price data DP1 that describes the deemed power procurement price obtained by such corrections.

[0047] The charge / discharge planning unit 14 is a component that actually creates a charge / discharge plan for a planning period for the storage battery 2. The charge / discharge planning unit 14 can selectively create two types of charge / discharge plans, namely, a main charge / discharge plan and a sub charge / discharge plan, or both of them, and can generate two types of charge / discharge plan data, namely, main charge / discharge plan data D0m and sub charge / discharge plan data D0s, corresponding to the two plans.

[0048] The main charge / discharge plan is generally created based on the idea of ​​prioritizing profits during charging and discharging, i.e., when there is a surplus of RE power generation, charging is prioritized because there is almost no need to procure power for charging, and when the power price is high, discharging is prioritized because high revenues are expected. When creating such a main charge / discharge plan, reference is made to deemed power procurement price data DP1 created by the power price information processing unit 13, storage battery actual data DB containing actual values ​​of the operating state of the storage battery 2 (remaining capacity: SoC, battery temperature, etc.) acquired from the control device 2c of the storage battery 2, and finalized plan data D0 describing a charge / discharge plan for the period from the creation of the charge / discharge plan to the plan target period, which has been created and finalized in advance in the charge / discharge plan creation mode of this embodiment.

[0049] On the other hand, the auxiliary charging and discharging plan is created based on a conventionally known concept, also called local production and consumption control, of preferentially consuming the power generated in the microgrid MG at the load 4 in the microgrid MG. In such local production and consumption control, the power generated in the renewable energy power generation device 3 is preferentially consumed by the load 4, and the surplus of the generated power is charged to the storage battery 2. When the demand of the load 4 cannot be met by the amount of RE power generation alone, power is supplied to the load 4 by discharging from the storage battery 2. When the demand cannot be met even by such discharging, power is purchased from the external grid 5. Furthermore, when the storage battery 2 reaches the end of its charging period, power is sold.

[0050] When both the main charging / discharging plan and the auxiliary charging / discharging plan are created, the adoption plan determination unit 15 calculates the profits from buying and selling electricity when the charging / discharging plans described in the main charging / discharging plan data D0m and the auxiliary charging / discharging plan data D0s are adopted, and determines which charging / discharging plan is better to adopt based on the results. The adoption plan determination unit 15 generates determination result data DR describing the results of the determination, and displays the determination results described in the determination result data DR on a display unit (not shown) of the energy management system 1.

[0051] When an operator of the energy management system 1 visually checks the judgment results and decides to adopt one of the charge / discharge plans and inputs the decision through an input unit (not shown), either the main charge / discharge plan data D0m or the sub charge / discharge plan data D0s, which describes the adopted charge / discharge plan, will be treated as new finalized plan data D0.

[0052] When only one of the main charging / discharging plan and the auxiliary charging / discharging plan is created, either the corresponding main charging / discharging plan data D0m or the corresponding auxiliary charging / discharging plan data D0s is treated as new confirmed plan data D0.

[0053] The supply and demand forecast display processing unit 16 is an optional component that performs processing for displaying, on a display unit (not shown) of the energy management system 1, a graph predicting the transition of the power demand and power generation amount when the charge and discharge plan created in the charge and discharge planning unit 14 is executed, based on the load demand forecast data DD and the power generation amount forecast data DE. When both the main charge and discharge plan and the sub charge and discharge plan are created, the graphs predicting the transition of both the plans may be displayed switchably or together.

[0054] Displaying the transition prediction graph allows the operator of the energy management system 1 to more specifically understand the content and effects of the created charge / discharge plan. Furthermore, when both the main charge / discharge plan and the sub charge / discharge plan are created and the operator decides which charge / discharge plan to adopt, the operator can refer to the transition prediction graph.

[0055] <Creating a main charging / discharging plan> Next, a description will be given of the creation of the main charge / discharge plan out of the two types of charge / discharge plans created in the energy management system 1. Fig. 3 is a diagram showing a flow for creating the main charge / discharge plan.

[0056] In this embodiment, the target period for creating the charge / discharge plans (both the main charge / discharge plan and the sub charge / discharge plan) is the whole day (24 hours) from the day after the plan creation date, and the plan is made for a total of 48 units of charge / discharge operations, each unit being 30 minutes. In this case, the charge / discharge plans for the day of the plan creation date and the following day are assumed to have already been created and described in the determined plan data D0.

[0057] In creating the main charge / discharge plan, first, the charge / discharge planning unit 14 calculates an initial charge amount, which is the SoC value at the start of the plan creation period, based on the SoC value at the time of plan creation (day) described in the storage battery performance data DB acquired from the control device 2c of the storage battery 2 and the charge / discharge plans for the day of plan creation and the day after described in the confirmed plan data D0 (step S1). Note that this initial charge amount is also referred to when creating the sub charge / discharge plan.

[0058] Next, the power price information processing unit 13 acquires the power price prediction data DP0 from the power exchange 6, acquires the load demand prediction data DD from the load demand prediction unit 11, and acquires the power generation amount prediction data DE from the RE power generation amount prediction unit 12 (step S2). Note that the acquisition of these data may be performed prior to the calculation of the initial charge / discharge amount.

[0059] The electricity price information processing unit 13 modifies the predicted price of electricity for the planning period, which is described in the electricity price prediction data DP0, based on the time change in the electricity demand of the load 4 for the planning period, which is described in the load demand prediction data DD, and the time change in the RE power generation amount for the planning period, which is described in the power generation amount prediction data DE, and generates deemed electricity procurement price data DP1 (step S3).

[0060] Fig. 4 is a diagram illustrating the generation of deemed power procurement price data DP1. In Fig. 4, a demand forecast profile PF1 showing the time change in the demand forecast for load 4 based on the description contents of load demand forecast data DD and a power generation amount forecast profile PF2 showing the time change in RE power generation amount based on the description contents of power generation amount forecast data DE are shown in a common coordinate space, and a forecast price profile PF3 showing the time change in the forecast price of electricity based on the description contents of power price forecast data DP0 is shown in a manner that aligns the horizontal axis, which is the time axis, with the coordinate space.

[0061] Note that Fig. 4 shows the maximum value (highest predicted price) Pmax and the minimum value (lowest predicted price) Pmin among the predicted prices of all 48 frames described in the power price prediction data DP0 obtained from the power exchange 6. Further, the discharge determination line TH1 and the charge determination line TH2, which are set by the following formula using a predetermined reference price width Pdif stored in a storage unit (not shown) of the energy management system 1 in advance, are also shown together.

[0062] TH1 = Pmax - Pdif; TH2 = Pmin + Pdif.

[0063] The discharge determination line TH1 is a boundary value at which discharge is not performed in frames where the predicted price is below that value, and the charge determination line TH2 is a boundary value at which charging is not performed in frames where the predicted price is above that value. When the relationship TH2 < TH1 holds as exemplified in Fig. 4, the virtual power procurement price data DP1 is generated.

[0064] In the case shown in Fig. 4, in the shaded portion between time t1 and time t2, the predicted value of the RE power generation amount exceeds the predicted value of the power demand at load 4. That is, the generation of surplus power is predicted. When charging such surplus power into the storage battery 2, as long as the amount of surplus power exceeds the chargeable capacity per frame, power purchase from the external power system 5 is unnecessary, so the power procurement cost is substantially zero. That is, the virtual power procurement price is substantially zero.

[0065] On the other hand, for frames where there is surplus power but the amount is less than the chargeable capacity per frame, when charging up to the full charge capacity and also performing power purchase in addition to charging the surplus power, a cost for such power purchase will occur. Therefore, for such frames, the cost for such power purchase is reflected in the virtual power procurement price.

[0066] More specifically, when the surplus power per frame is Ps, the chargeable capacity per frame is CHm, the predicted price of electricity is price, and the procurement cost of surplus power per frame is Dp, the deemed power procurement price per frame is When CHm≦Ps, Dp×CHm When CHm>Ps, (CHm-Ps)×price+Dp×CHm However, as mentioned above, the procurement cost Dp can be considered to be essentially 0.

[0067] The deemed electricity procurement price is used in the creation of the main charge / discharge plan in the charge / discharge planning unit 14 and in the calculation of the expected profit amount based on the main charge / discharge plan in the adoption plan determination unit 15.

[0068] Figure 4 also separately shows the deemed electricity procurement price profile PF4, which shows the time variation of the deemed electricity procurement price set from the demand forecast, RE electricity generation forecast, and predicted electricity price, which respectively give the demand forecast profile PF1, the electricity generation forecast profile PF2, and the forecast price profile PF3.

[0069] In this deemed power procurement price profile PF4, the deemed power procurement price before time t1 when demand exceeds RE power generation and after time t2 is the same as in the forecast price profile PF3. Meanwhile, between time t1 and time t2 when surplus power is generated, the deemed power procurement price is zero for most of the time. However, during the predetermined time Δta from time t1 and the predetermined time Δtb until time t2, the amount of surplus power is small compared to the charging capacity per frame, so the deemed power procurement price is lower than the forecast price but not zero.

[0070] The charge / discharge planning unit 14 sets the frames for charging / discharging (charge / discharge frames) based on the deemed power procurement price data DP1 that provides the deemed power procurement price profile PF4. Hereinafter, among the charge / discharge frames, frames to which discharging is assigned will be referred to as discharge frames, and frames to which charging is assigned will be referred to as charge frames. Furthermore, frames in which neither charging nor discharging is performed will be referred to as rest frames. Figures 5 to 8 are diagrams for explaining how to set such charge / discharge frames.

[0071] FIG. 5(a) shows the same assumed electricity procurement price profile PF4 as shown in FIG. 4, along with a discharge judgment line TH1 and a charge judgment line TH2.

[0072] The charge / discharge planning unit 14 first sorts the deemed power procurement prices of all 48 frames described in the power price prediction data DP0 generated by the power price information processing unit 13 (step S4). Then, based on the results of this sorting, it sets the charge / discharge frames. As a basic concept, frames with high deemed power procurement prices are preferentially assigned to discharge frames, and frames with low deemed power prices are preferentially assigned to charge frames.

[0073] Figure 5(b) shows a state in which some frames that belong to the time period ΔtD1 when the deemed procurement price is the highest in the electricity procurement price profile PF4 are assigned to the discharging frame D1, and some frames that belong to the time period ΔtC1 when the deemed procurement price is the lowest (0) are assigned to the charging frame C1.

[0074] To be clear, in Figure 5(b) and Figures 6 to 8, the size of the charging and discharging tops in the direction of the horizontal axis AX corresponds to the number of tops assigned, but the size of each top shown is merely approximate for the purpose of explanation and is not exact.

[0075] 5(b) and 6 to 8 also show the power procurement price profile PF4, but the horizontal axis AX merely indicates the reference (i.e., the zero point of power) for the discharge power in the discharging frame and the charge power in the charging frame, and is not intended to indicate that discharging occurs in the portion of the power procurement price profile PF4 above the horizontal axis AX and charging occurs in the portion below. Allocation to discharging frames is strictly limited to the range of deemed procurement prices higher than the discharging judgment line TH1, and allocation to charging frames is strictly limited to the range of deemed procurement prices lower than the charging judgment line TH2.

[0076] Figure 6 shows the allocation of discharging frame D2 and charging frame C2 following the allocation of discharging frame D1 and charging frame C1 shown in Figure 5(b). Discharging frame D2 is assigned the frame with the highest deemed procurement price after the time ΔtD1 to which discharging frame D1 was assigned. On the other hand, charging frame C2 is assigned the frame with a deemed procurement price of 0, the same as the time ΔtC1 to which charging frame C1 was assigned.

[0077] Thereafter, similarly, the frames are allocated to discharging frames in descending order of deemed procurement price, and the frames are allocated to charging frames in descending order of deemed procurement price.

[0078] Specifically, the initial charge amount is first allocated in descending order of the deemed power procurement price (step S5). That is, the discharge frame for preferentially discharging the amount of initial charge is set in descending order of the deemed power procurement price.

[0079] Furthermore, the amount of charging energy that needs to be carried over to the next day is allocated in order from the frame with the lowest deemed power procurement price (step S6). That is, a charging frame is set in which charging is given priority to ensure the amount of charging energy required for discharging from the next day of the planning period (three days after the planning creation date) onwards (step S6). Note that when discharging is allocated, it is necessary to store electricity in excess of the amount to be discharged at the time of the relevant discharging prior to the discharging based on the allocation.

[0080] Once these priority charge / discharge frames have been set, the charge / discharge planning unit 14 then identifies a pair of frames with the highest and lowest deemed electricity procurement prices among the frames that have not yet been set as charge / discharge frames (step S7). Thereafter, allocation to discharge frames and allocation to charge frames are always performed in pairs. Furthermore, when setting such pairs, charging is performed before discharging.

[0081] Then, the charge / discharge planning unit 14 determines whether the identified pair is profitable (step S8). If it is determined that the pair is profitable (YES in step S8), the frame with the lower deemed power procurement price in the pair is set as the charging frame, and the frame with the higher deemed power procurement price is set as the discharging frame (step S9).

[0082] For example, if any of the following conditions is met, the charge / discharge planning unit 14 determines that the pair is profitable.

[0083] (Condition 1) The deemed procurement price Phigh of the unit to be allocated to the discharging unit is higher than the discharge judgment line TH1, and the deemed procurement price Plow of the unit to be allocated to the charging unit is lower than the charge judgment line TH2; (Condition 2) Charge / discharge efficiency > Phigh / Plow.

[0084] When the setting of the charging frame and the discharging frame for a certain pair is completed, the charge / discharge planning unit 14 again identifies a new pair and assigns it to the charging / discharging frame in step S7. This is repeated until the identified pair is determined to be unprofitable (NO in step S8).

[0085] Fig. 7 shows the state when allocating possible charge / discharge pairs is complete, i.e., when the processing of step S5 is completed. Specifically, Fig. 7 shows the state where the first discharging frame group DAα1 and the second discharging frame group DAα2, each of which has several discharging frames allocated to them, form the total discharging frame group DAα, and the state where all consecutive frames between time t3 and time t4 are allocated to charging frames, form the total charging frame group CAα.

[0086] When the allocation of charge / discharge frames is completed in this manner, the charge / discharge plan is temporarily created. The charge / discharge planning unit 14 executes a simulation of the charge / discharge operation according to the charge / discharge plan, and checks whether a situation occurs in which the SoC deviates from the upper or lower limit, i.e., whether a situation in which the SoC fails occurs (step S10).

[0087] In other words, the charge / discharge planning unit 14 determines whether the SoC satisfies the preset constraints when the charge / discharge operation is performed according to the created charge / discharge plan. If it is determined that the constraints are not satisfied, the allocation is changed, giving priority to the frames belonging to pairs with low profitability.

[0088] If discharging is planned even though the storage battery 2 has reached the end of discharge, a situation occurs in which the SoC deviates from the lower limit (SoC lower limit failure) (NO in step S10). In such a case, since the assigned discharging operation cannot actually be performed, the discharging of the frame with the lowest deemed power procurement price among the discharging frames before the frame that leads to the SoC lower limit failure is canceled (step S14). In other words, the discharging frame is changed to a pause frame.

[0089] Furthermore, if charging is planned even though the storage battery 2 has reached the end of charging, a situation occurs in which the SoC exceeds the upper limit (SoC upper limit breach) (NO in step S20). In such a case, since the assigned charging operation cannot actually be performed, charging of the frame with the highest deemed power procurement price among the charging frames before the frame that led to the SoC upper limit breach is canceled (step S15). In other words, the charging frame is changed to a paused frame.

[0090] 7, all frames from time t3 to time t4 are assigned to charging frames, forming a total charging frame group CAα, and continuous charging is planned from time t3 to time t4. In this case, if the SoC upper limit failure occurs at time t5 during charging (NO in step S10), the charging scheduled for the following time Δtα cannot actually be performed.

[0091] When the charge / discharge planning unit 14 determines that such an SoC upper limit breach will occur, it selects frames for the time Δtα from among the frames included in the entire charging frame group CAα that existed before time t5, in descending order of deemed power procurement price, as shown in Fig. 8. Then, it changes the selected frames from charging frames to rest frames.

[0092] Then, a simulation of the charge and discharge operation is performed again for the changed charge and discharge plan to check whether a situation that would cause the SoC to fail occurs (step S10).

[0093] For example, if some of the charging frames are changed to rest frames as shown in Figure 8, while all of the discharging frame group DAα remains as shown in Figure 7, even though some of the originally planned charging has been canceled, discharging will remain as originally planned.In such a case, a violation of the SoC lower limit may occur in the next simulation (NO in step S10).

[0094] FIG. 8 shows a case where, in response to such a lower limit breach, the charge / discharge planning unit 14 further selects several charging frames in ascending order of deemed power procurement price and changes them to pause frames.

[0095] This simulation and the change from the charge / discharge frame to the rest frame according to the results are repeated until no SoC breakdown occurs.

[0096] When simulating the charging and discharging operation according to the above-described charging and discharging plan, a simulation of the temperature of the storage battery 2 may be performed in parallel, and if the temperature simulation determines that the temperature of the storage battery 2 deviates from a predetermined control range, the charging and discharging frame that caused the deviation may be set to a pause frame.

[0097] That is, the charge / discharge planning unit 14 may also determine whether the temperature of the storage battery 2 satisfies the pre-set constraint conditions when a charge / discharge operation is performed in accordance with the created charge / discharge plan, and if it is determined that the constraint conditions are not satisfied, the allocation may be changed, giving priority to frames belonging to pairs with low profitability.

[0098] If the simulation results show that no SoC failure occurs (YES in step S10), the charge / discharge planning unit 14 sets the charge / discharge plan for all 48 frames at this point in time as the main charge / discharge plan, and outputs main charge / discharge plan data D0m that describes its contents (step S11).

[0099] For example, as shown in Figure 8, if the total discharging frame group DA consists of a first discharging frame group DA1, a second discharging frame group DA2, and a third discharging frame group DA3, each consisting of several frames, and the total charging frame group CA consists of multiple consecutive frames, and if SoC failure no longer occurs, the main charging / discharging plan data D0m will be written so that the frames included in the total discharging frame group DA are to be discharged, the frames included in all charging frames are to be charged, and the other frames are to be paused.

[0100] Note that the explanation regarding the generation of the main charge-discharge plan data D0m up to this point is based on the premise that the relationship TH2 < TH1 holds between the discharge determination line TH1 and the charge determination line TH2. However, depending on the content of the power price prediction data DP0, the relationship TH2 ≥ TH1 may also hold.

[0101] In such a case, the charge-discharge planning unit 14 sets all 48 frames as pause frames. That is, no charge-discharge is performed in any frame, and a main charge-discharge plan is created such that the charge-discharge power is set to 0, and the main charge-discharge plan data D0m describing the content is output.

[0102] When the main charge-discharge plan data D0m is generated, the adoption plan determination unit 15 calculates the expected profit amount (main plan profit) when the main charge-discharge plan is executed based on the main charge-discharge plan described in the main charge-discharge plan data D0m and the assumed power procurement price (step S812). Note that when the main expected profit is calculated, or in parallel with the calculation of the main expected profit, the charge-discharge planning unit 14 calculates the predicted value of the SoC at the end of the planned period (step S13).

[0103] More specifically, the main plan profit is calculated by the formula ΣW(k)·P(k), where W(k) is the charge-discharge power amount (positive for discharge and negative for charge) in the k-th frame of all 48 frames, and P(k) is the assumed power procurement price in the t-th frame.

[0104] As described above, the main charge-discharge plan is created based on the concept of emphasizing the profit during charge-discharge, that is, when there is an excess in the RE power generation amount, charging is preferentially performed because the power procurement cost for charging is almost unnecessary, and when the power price is high, discharging is preferentially performed because high income is expected. Therefore, when the storage battery 2 is operated based on the main charge-discharge plan, it is expected to obtain high profits.

[0105] In other words, the main charging and discharging plan can be said to be a plan intended to further improve the value of electricity in the microgrid.

[0106] <Creating a secondary charging / discharging plan> Next, we will explain how to create a secondary charging and discharging plan in the energy management system 1. As described above, the secondary charging and discharging plan is created based on the conventionally known concept of local production and consumption control, and therefore, only an outline thereof will be shown below.

[0107] For example, when the load demand prediction unit 11 and the RE power generation prediction unit 12 respectively perform a demand prediction and a RE power generation prediction that give a demand prediction profile PF1 and a power generation prediction profile PF2 as shown in FIG. 4, the frames between time t1 and time t2 where a surplus is predicted to occur are sequentially set as charging frames.

[0108] However, if it is predicted that the charging end will be reached before time t2, the period from the time when the charging end is reached to time t2 is set as a pause period. During this period, electricity is sold from the renewable energy power generation device 3 to the external grid 5.

[0109] From time t2 onwards until the end of discharge is reached, the frame is set as a discharge frame in which RE power is discharged to the load 4 to make up for the shortfall in RE power generation relative to demand. After the end of discharge is reached, the frame is set as a rest frame until the next charging with surplus power is performed. Demand that cannot be met by discharging from the storage battery 2 is met by purchasing power from the external grid 5.

[0110] The behavior from the start of the planned period up to time t1 is basically the same as that for time t2. However, if the initial charge amount at the start is not 0, the frames up to the end of discharge are set as discharge frames, and then the frames up to time t1 are set as rest frames. On the other hand, if the initial charge amount at the start of the planned period is 0, all frames up to time t1 are set as rest frames.

[0111] The charge / discharge planning unit 14 creates the auxiliary charge / discharge plan in the above-described manner, and outputs auxiliary charge / discharge plan data D0s that describes the contents of the plan.

[0112] When the auxiliary charging and discharging plan data D0s is generated, the adoption plan determination unit 15 calculates the predicted profit amount (sub-plan profit) when the auxiliary charging and discharging plan is executed, based on the auxiliary charging and discharging plan described in the auxiliary charging and discharging plan data D0s and the predicted price of electricity described in the electricity price prediction data DP0. When the predicted auxiliary profit is calculated, or in parallel with the calculation of the predicted auxiliary profit, the charging and discharging planning unit 14 calculates the predicted value of SoC at the end of the planning period.

[0113] More specifically, the sub-plan revenue is calculated by the formula ΣW(k)·price(k), which is the sum of W(k)·price(k) for each of the 48 frames, where W(k) is the amount of charged / discharged electricity (positive for discharge and negative for charge) in the kth frame of the total 48 frames, and price(k) is the predicted price of electricity in the tth frame.

[0114] <Decision on adopting charging and discharging plans> When only one of the main charging / discharging plan data D0m and the auxiliary charging / discharging plan data D0s is generated, the charging / discharging plan described in the generated data is adopted as is. In this case, the adopted plan determination unit 15 generates determination result data DR describing the adopted charging / discharging plan and the amount of revenue when the storage battery 2 is operated in accordance with the adopted charging / discharging plan calculated in the above-mentioned manner. The generated main charging / discharging plan data D0m or auxiliary charging / discharging plan data D0s is thereafter treated as the final plan data D0 for the charging / discharging operation to be performed two days after the time of plan creation.

[0115] On the other hand, when both the main charging / discharging plan data D0m and the sub-charging / discharging plan data D0s are generated, the adoption plan determination unit 15 calculates the amount of revenue (main plan revenue and sub-plan revenue) when the storage battery is operated according to each charging / discharging plan, in the same way as when only one of them is generated.

[0116] The adoption plan determination unit 15 further compares the main plan profit with the sub-plan profit. If the main plan profit is greater than or equal to the sub-plan profit, it determines that the main charge / discharge plan should be adopted as the charge / discharge plan for the storage battery 2, and if the main plan profit is less than the sub-plan profit, it determines that the sub-plan should be adopted as the charge / discharge plan for the storage battery 2, and generates determination result data DR that describes the content and result of the determination, including the profit amount, for each case.

[0117] In many cases, it is expected that the main plan profit obtained when adopting a main charging / discharging plan that is created based on the idea of ​​emphasizing profits during charging / discharging will be higher than the sub-plan profit obtained when adopting a sub-charging / discharging plan, but the way in which demand in the load 4 and the amount of RE power generated by the renewable energy power generation device 3 change varies from day to day, and depending on the way they change, the relationship between the main plan profit and the sub-plan profit may be reversed.

[0118] Therefore, by determining the charge / discharge plan to be adopted based on the magnitude relationship between the main plan profit and the sub-plan profit, the storage battery 2 can be operated so as to more reliably obtain a high profit.

[0119] The contents of the determination result data DR are displayed on a display unit (not shown) of the energy management system 1. In addition, the main charging / discharging plan data D0m or the sub charging / discharging plan data D0s adopted as the charging / discharging plan is thereafter treated as the finalized plan data D0 for the planning period.

[0120] In addition, if the creation of a charge / discharge plan based on the above explanation is set in advance to start at a certain timing on the plan creation date, it is possible to automatically create and adopt the charge / discharge plan.

[0121] Alternatively, the adoption plan determination unit 15 may simply display the main plan profit and the sub-plan profit on the display unit, and the operator of the energy management system 1 may determine whether to adopt the main charging / discharging plan data D0m or the sub-charging / discharging plan data D0s.

[0122] As described above, according to this embodiment, a charge / discharge plan for a storage battery in a microgrid that includes a storage battery, a renewable energy power generation device, and a load can be created and executed based on the idea of ​​prioritizing profits during charging and discharging, in which charging is prioritized when there is a surplus of RE power generation because there is almost no cost to procure electricity for charging, and discharging is prioritized when electricity prices are high because high income is expected.

[0123] Furthermore, by comparing a charge / discharge plan created based on this concept with a charge / discharge plan created based on the concept of emphasizing local production and consumption control, it is possible to adopt and execute a charge / discharge plan that is expected to bring about a higher profit. Furthermore, the creation and adoption of such a charge / discharge plan can be performed automatically.

[0124] In a power system in which a large number of microgrids such as those shown in this embodiment are connected to an external system, which is a commercial power system, if a charge / discharge plan for the storage batteries provided in each microgrid is created and executed as in this embodiment, it becomes possible to control each storage battery individually in conjunction with the electricity market price. Considering that electricity demand is high and sometimes even tight during times when the electricity market price is high, adopting such an embodiment is expected to reduce the power procurement cost of each microgrid and also to have the effect of easing congestion in the external system.

[0125] <Demand and supply forecast display> As described above, the energy management system 1 may be equipped with the supply and demand forecast display processing unit 16, and may be configured to display, on a display unit (not shown), a forecast graph of the trends in the amount of electricity demand and the amount of electricity generated if the main charging / discharging plan or the sub-charging / discharging plan is executed.

[0126] FIG. 9 is a graph showing predicted transitions of the amount of power demand and the amount of power generated when a main charge / discharge plan is executed over two days.

[0127] Such a trend prediction graph may be displayed based on the charge / discharge plan adopted by the adoption plan determination unit 15, or alternatively, a trend prediction graph may be displayed in a switchable manner when the main charge / discharge plan and the sub charge / discharge plan that are candidates for adoption are each executed, and the operator of the energy management system 1 refers to the displayed contents to decide which charge / discharge plan to adopt.

[0128] <Second embodiment> In the above-described first embodiment, the energy management system 1 provided in the microgrid MG functions as a charge / discharge plan creation device capable of creating a charge / discharge plan for a storage battery that prioritizes profits during charging and discharging. However, the configuration in which such a charge / discharge plan is created and used is not limited to the microgrid MG.

[0129] In this embodiment, a case will be described in which the charge and discharge plan creation device is used in a situation where an off-site PPA (Power Purchase Agreement) has been established.

[0130] Fig. 10 is a schematic configuration diagram of a power system 100 owned by a power generation company and a load system 200 owned by a consumer when an off-site PPA (Power Purchase Agreement) has been concluded. In Fig. 10, components common to those in the first embodiment are given the same reference numerals as those in the first embodiment, and detailed descriptions thereof will be omitted.

[0131] The power system 100 mainly includes an energy management system 1B, a storage battery 2, and a renewable energy power generation device 3. The operations of the storage battery 2 and the renewable energy power generation device 3 are controlled by respective control devices 2c and 3c. On the other hand, the load system 200 mainly includes a load 4. The operation of the load 4 is controlled by a control device 4c. When an off-site PPA is established, the power system 100 and the load system 200 are separated from each other.

[0132] The energy management system 1B is realized by a computer, similar to the energy management system 1 provided in the microgrid MG according to the first embodiment. The energy management system 1B is communicatively connected to the control devices 2c and 3c, and is also communicatively connected to the control device 4c of the load 4 via a network (Internet) N. The energy management system 1B not only issues control instructions for each of the control objects to each of the control devices 2c, 3c, and 4c, but also acquires various state information (e.g., actual operation values, fault information, etc.) for each of the control objects from each of the control devices 2c, 3c, and 4c.

[0133] In this embodiment, under the control of the energy management system 1B, the discharged power from the storage battery 2 provided in the power system 100 and the generated power in the renewable energy power generation device 3 are supplied to the load 4 of the load system 200 via an external system 5.

[0134] In addition, the energy management system 1B includes the functional components shown in FIG. 2, similar to the energy management system 1 included in the microgrid MG according to the first embodiment.

[0135] However, the charge / discharge planning unit 14 of the energy management system 1B does not create a secondary charge / discharge plan. Therefore, in the present embodiment, the main charge / discharge plan described in the main charge / discharge plan data D0m is adopted as the charge / discharge plan as is.

[0136] Despite this difference, the energy management system 1B also functions as a charge / discharge plan creation device for the storage battery 2, having the same functions as the energy management system 1 provided in the microgrid MG according to the first embodiment.

[0137] As described above, in this embodiment, as in the first embodiment, a charge / discharge plan can be created and executed based on the idea of ​​prioritizing profits during charging and discharging, in which charging is prioritized when there is a surplus of RE power generation because there is almost no cost to procure electricity for charging, and discharging is prioritized when electricity prices are high because high income is expected.

[0138] <Modification> In the first embodiment described above, the charge / discharge plan for operating the storage battery 2 is selected from the main discharge plan and the secondary discharge plan, whichever is expected to produce a higher profit, but the selection criteria are not limited to this. For example, at least one of the following indices may be used in addition to or instead of the profit:

[0139] Local production and consumption rate (consumption): the ratio of RE generation to demand; Local consumption rate (production): The percentage of RE generated that is consumed and charged within the microgrid MG; Contribution of storage battery to local consumption: The ratio of discharge from storage battery to the demand power covered by RE power generation; Surplus energy utilization rate: The percentage of surplus electricity that is charged to the storage battery.

[0140] <Application example> In the second embodiment, a case is described in which, in a situation where an off-site PPA has been established, the energy management system 1B provided in the power system 100 owned by the power generation company functions as a charge / discharge plan creation device for the storage battery 2. However, the idea of ​​creating a charge / discharge plan for the storage battery by prioritizing profits during charging / discharging can also be applied to cases in which the relationship with demand in a load system owned by a consumer is not taken into consideration.

[0141] For example, in an energy storage business that earns revenue by charging and discharging storage batteries, the relationship between the demand in the load and the amount of power discharged from the storage batteries is not usually directly taken into consideration.

[0142] Fig. 11 is a schematic configuration diagram of the facilities of a power storage system 300, which is a power system owned by such a power storage business operator. In Fig. 11, components common to the first and second embodiments are given the same reference numerals as in the first and second embodiments, and detailed description thereof will be omitted.

[0143] The power storage system 300 mainly includes an energy management system 1C, a storage battery 2, and a renewable energy power generation device 3. The operations of the storage battery 2 and the renewable energy power generation device 3 are controlled by respective control devices 2c and 3c.

[0144] The energy management system 1C is realized by a computer, similar to the energy management system 1 provided in the microgrid MG according to the first embodiment. The energy management system 1C is communicatively connected to the control devices 2c and 3c. The energy management system 1C not only issues control instructions for each of the control objects to each of the control devices 2c and 3c, but also acquires various state information (e.g., operation performance values, fault information, etc.) for each of the control objects from each of the control devices 2c and 3c.

[0145] In this embodiment, charging and discharging between the storage battery 2 provided in the power storage system 300 and the external system 5, and discharging from the renewable energy power generation device 3 to the storage battery 2 and the external system 5 are performed under the control of the energy management system 1C.

[0146] In addition, the energy management system 1C includes all of the functional components of the energy management system 1 provided in the microgrid MG of the first embodiment shown in Figure 2, except for the load demand prediction unit 11 and the supply and demand prediction display processing unit 16.

[0147] Furthermore, the charge / discharge planning unit 14 of the energy management system 1C does not create a secondary charge / discharge plan. Therefore, in this embodiment, the main charge / discharge plan described in the main charge / discharge plan data D0m is adopted as the charge / discharge plan as is.

[0148] Despite these differences, the energy management system 1C also has the same functions as the energy management system 1 provided in the microgrid MG according to the first embodiment, and functions as a charge / discharge plan creation device for the storage battery 2. Unlike the first and second embodiments, the energy management system 1C does not take into account the demand of consumers when creating a charge / discharge plan.

[0149] Based on this premise, the electricity price information processing unit 13 generates deemed electricity procurement price data DP1 based on the electricity price prediction data DP0 obtained from the electricity exchange 6 and the electricity generation amount prediction data DE generated by the RE electricity generation amount prediction unit 12.

[0150] Specifically, in the case of this embodiment, the load demand forecast data DD is not generated by the load demand forecasting unit 11, and naturally, the demand forecast profile PF1 shown in Fig. 4 is not conceived. Therefore, the power generation amount forecast data DE itself is referenced as the power generation amount forecast profile PF2 in Fig. 4 when generating the deemed power procurement price data DP1. From another perspective, this means that the value of the demand forecast profile PF1 is constant at 0, and therefore the entire peak in the deemed power generation amount forecast profile PF2 is regarded as surplus power, and the deemed power procurement price data DP1 is generated accordingly.

[0151] In such a case, for a frame where the amount of RE power generation exceeds the chargeable amount in the storage battery 2, the deemed electricity procurement price is set to zero, and for a frame where the amount of RE power generation is less than the chargeable amount, a price according to the amount of RE power generation is set based on the description in the electricity price prediction data DP0.

[0152] When the charge / discharge planning unit 14 creates a charge / discharge plan based on the generated deemed power procurement price data DP1, similarly to the first and second embodiments, a frame with a high deemed power procurement price is preferentially allocated to a discharging frame, and a frame with a low deemed power price is preferentially allocated to a charging frame. In addition, surplus RE power generation is sold.

[0153] The above aspect is also common to the first and second embodiments in that a charge / discharge plan is created and executed based on the idea of ​​prioritizing profits during charge / discharge. [Explanation of symbols]

[0154] 1. Energy Management System 1B Energy Management System 1C Energy Management System 100 Power Systems 200 Resistance System 300 Energy Storage System C1, C2 charging top CAα, CA all charging frames D1, D2 discharge top DAα1, DA1 First discharge top group DAα2, DA2 second discharge top group DA3 Third discharge top group DAα, DA full discharge top group PF1 Demand Forecast Profile PF2 Power Generation Forecast Profile PF3 Forecast Price Profile PF4 Electricity Procurement Price Profile

Claims

1. A device that creates a charge / discharge plan for a predetermined planning period for a storage battery that constitutes a power system connected to an external system that is an external commercial power system, together with a renewable energy power generation device and a load, for each unit time segment, a renewable energy power generation prediction unit that generates power generation prediction data that describes a predicted value of the power generation amount in the renewable energy power generation device for each unit time segment; a load demand prediction unit that generates load demand prediction data that describes a predicted value of demand for the load for each unit time segment; an electricity price information processing unit that generates deemed electricity procurement price data that describes a deemed electricity procurement price for each unit time segment that serves as a reference for allocating charging operations and discharging operations in the storage battery to each unit time segment; and a charge / discharge planning unit that creates the charge / discharge plan based on the deemed electricity procurement price data; Equipped with the power price information processing unit externally acquires power price forecast data that describes a predicted value of the power price for each unit time interval when power is bought and sold between the power system and the external system, acquires the power generation amount forecast data and the load demand forecast data, and generates the deemed power procurement price data by correcting the predicted value of the power price for each unit time interval in which the predicted value of the power generation amount exceeds the predicted value of the demand according to the difference between the chargeable capacity of the storage battery for each unit time interval and the predicted value of the power generation amount; the charge / discharge planning unit pairs the unit time segments to which the charging operations are to be allocated with the unit time segments to which the discharging operations are to be allocated, and allocates the discharging operations preferentially from the unit time segments in which the deemed power procurement price described in the deemed power procurement price data is high, and allocates the charging operations preferentially from the unit time segments in which the deemed power procurement price is low, thereby creating a main charge / discharge plan as the charge / discharge plan. A charge and discharge plan creation device.

2. The charge / discharge plan creation device according to claim 1, the charge / discharge planning unit determines whether at least one of a remaining capacity or a temperature of the storage battery satisfies a predetermined constraint condition when the storage battery performs a charge / discharge operation according to the main charge / discharge plan; If it is determined that the constraint is not satisfied, the allocation is changed, giving priority to the slots belonging to the least profitable pairs. A charge and discharge plan creation device.

3. The charge / discharge plan creation device according to claim 1 or 2, the charge / discharge planning unit is capable of creating a sub-charge / discharge plan selectively with or together with the main charge / discharge plan, In the auxiliary charging and discharging plan, the power generated by the renewable energy power generation device is consumed by the load with priority, and the surplus of the generated power is charged to the storage battery. When the demand of the load cannot be met by the generated power alone, power is supplied to the load by discharging from the storage battery. When the demand cannot be met even by discharging, power is purchased from the external system. When the storage battery reaches the end of charging, power is sold to the external system. Charging and discharging operations are allocated for each unit time segment. A charge and discharge plan creation device.

4. The charge / discharge plan creation device according to claim 3, an adoption plan determination unit that, when the main charging / discharging plan and the auxiliary charging / discharging plan are both created, calculates a main plan profit that is the amount of profit that will be obtained when the main charging / discharging plan is executed and a auxiliary plan profit that is the amount of profit that will be obtained when the auxiliary charging / discharging plan is executed, and determines a charge / discharge plan to be adopted for the operation of the storage battery based on a result of comparison between the main plan profit and the auxiliary plan profit; Furthermore, The adoption plan determination unit adopts the main charging / discharging plan when the main plan profit is equal to or greater than the sub-plan profit, and adopts the sub-charging / discharging plan when the sub-plan profit is greater than the main plan profit. A charge and discharge plan creation device.

5. The charge / discharge plan creation device according to claim 1, a supply and demand forecast display processing unit that displays, on a predetermined display unit, a graph predicting transitions of the demand for electricity and the amount of power generated when the charge and discharge plan is executed, based on the charge and discharge plan created in the charge and discharge planning unit, the power generation amount forecast data, and the load demand forecast data; The charge and discharge plan creation device further comprises:

6. The charge / discharge plan creation device according to claim 1, The power system is a microgrid including the renewable energy power generation device, the load, and the storage battery. A charge and discharge plan creation device.

7. A method for creating a charge / discharge plan for a predetermined planning period for a storage battery that constitutes a power system connected to an external system that is an external commercial power system, together with a renewable energy power generation device and a load, for each unit time segment, a) generating power generation amount prediction data that describes a predicted value of the power generation amount in the renewable energy power generation device for each unit time segment; b) generating load demand forecast data that describes a forecast value of the demand in the load for each unit time segment; c) generating deemed power procurement price data that describes deemed power procurement prices for each unit time segment that serve as a basis for allocating charging and discharging operations in the storage battery to each unit time segment; d) creating the charge / discharge plan based on the deemed electricity procurement price data; Equipped with In the step c), electricity price forecast data is externally acquired, which describes a predicted value of the electricity price for each unit time interval when electricity is bought and sold between the electricity system and the external system, and the power generation amount forecast data and the load demand forecast data are acquired, and the predicted value of the electricity price for each unit time interval in which the predicted value of the electricity generation amount exceeds the predicted value of the demand is corrected according to the difference between the chargeable capacity of the storage battery for each unit time interval and the predicted value of the electricity generation amount, thereby generating the deemed electricity procurement price data; In the step d), the unit time segments to which the charging operations are to be allocated are paired with the unit time segments to which the discharging operations are to be allocated, and the discharging operations are preferentially allocated to the unit time segments in which the deemed power procurement price described in the deemed power procurement price data is high, and the charging operations are preferentially allocated to the unit time segments in which the deemed power procurement price is low, thereby creating a main charging / discharging plan as the charging / discharging plan. A charge and discharge plan creation method comprising:

8. The charge / discharge plan creation method according to claim 7, e) determining whether or not at least one of the remaining capacity and temperature of the storage battery satisfies a predetermined constraint condition when the storage battery performs a charge / discharge operation in accordance with the main charge / discharge plan, and if it is determined that the constraint condition is not satisfied, changing the allocation by giving priority to a battery belonging to a pair with low profitability; The charge / discharge plan creation method further comprises:

9. The charge / discharge plan creation method according to claim 7 or 8, In the step d), a sub-charging / discharging plan can be created selectively with or together with the main charging / discharging plan, In creating the auxiliary charging and discharging plan, charging and discharging operations are allocated for each unit time segment so that the power generated by the renewable energy power generation device is consumed by the load with priority, and the surplus of the generated power is charged to the storage battery, and when the demand of the load cannot be met by the generated power alone, power is supplied to the load by discharging from the storage battery, and when the demand cannot be met even by discharging, power is purchased from the external system, and when the storage battery reaches the end of charging, power is sold to the external system. A charge and discharge plan creation method comprising:

10. The charge / discharge plan creation method according to claim 9, f) calculating a main plan profit, which is the amount of profit that will be obtained when the main charging / discharging plan and the auxiliary charging / discharging plan are executed, when both the main charging / discharging plan and the auxiliary charging / discharging plan are created, and determining a charging / discharging plan to be adopted for the operation of the storage battery based on a result of comparing the main plan profit with the auxiliary plan profit; Furthermore, In the step f), when the main plan profit is equal to or greater than the sub-plan profit, the main charging / discharging plan is adopted, and when the sub-plan profit is greater than the main plan profit, the sub-charging / discharging plan is adopted. A charge and discharge plan creation method comprising:

11. The charge / discharge plan creation method according to claim 7, The power system is a microgrid including the renewable energy power generation device, the load, and the storage battery. A charge and discharge plan creation method comprising:

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