Power Management Device

Abstract

To provide a power management device, a power management system, and a power management method, capable of power supply tracking even in a system having a power storage device.SOLUTION: A power management device that is connected to a power storage device of a consumer facility having: a block chain, to which a plurality of nodes are connected; and the power storage device capable of charging power based on purchased power and renewable energy, includes: a power information acquisition unit that acquires the measurement result of measuring the power generated by renewable energy and the measurement result of measuring the power output from the power storage device; a tracking information generating unit that generates tracking information representing a charge rate charged according to the renewable energy in the power storage device and a charge rate charged according to the purchased power, among the charge rates of the power storage device, based on the measurement results obtained by acquiring power information, when charging the power storage device; and a registration request unit that transmits the generated tracking information to the first node among the plurality of nodes and requests registration in a distributed ledger.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power management device. Place Regarding. [Background technology]

[0002] As there is a demand for a significant reduction in greenhouse gas emissions that cause climate change, major companies have been actively strengthening their environmental management efforts for the sustainable development of society and their own companies. For example, the number of companies participating in the international corporate alliance "RE100," which aims to cover all electricity used in business activities with renewable energy (hereafter referred to as "renewable energy"), has been increasing year by year, with 288 companies participating worldwide, of which 50 are Japanese (as of February 2021). Participating companies are required to declare plans and goals to cover their business operations with 100% renewable energy, which indicates a sharp rise in the need to increase the renewable energy utilization rate. In order for companies to increase their renewable energy utilization rate, they need to procure electricity that has been proven to have environmental value as it is derived from renewable energy.

[0003] Possible methods for procuring renewable energy electricity include (a) setting up a renewable energy power plant on one's own premises and consuming it, (b) setting up an off-site renewable energy power plant in-house and self-consigning it, and (c) procuring it from a retail electricity supplier. In addition, one possible method for proving the environmental value of renewable energy electricity is power source tracking using blockchain, for example. Since it is possible to prove the environmental value of renewable energy electricity supplied on one's own premises or from external sources, it is possible to achieve reliable management of renewable energy utilization rates without losing environmental value. An example of a public technology related to power source tracking is an energy trading system in which power facilities or power generation facilities having surplus power trade directly with power storage facilities (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-153275 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, power source tracking has the problem that tracking is difficult when a storage device such as a storage battery is present in the grid. For example, when a storage battery connected to both a solar power generation device and a commercial grid is charged and then power is output from the storage battery, it is not possible to determine whether the power is purchased power or solar power. This makes power source tracking difficult, and makes it difficult to prove the usage of renewable energy power.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power management device that enables power supply tracking even in a system having a power storage device. Place The purpose is to provide. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, one aspect of the present invention is a power management device connected to a blockchain to which multiple nodes are connected and a power storage device of a consumer facility having the power storage device capable of charging purchased power and power based on renewable energy, the power management device having the power storage device, the power management device including: a power information acquisition unit that acquires measurement results of measuring the power generated by the renewable energy and measurement results of measuring the power output from the power storage device; a tracking information generation unit that generates tracking information when discharging from the power storage device based on the measurement results obtained by the power information acquisition unit, the tracking information including, among the charging rates of the power storage device, the charging rate at the power storage device that is charged due to renewable energy and the charging rate that is charged due to purchased power, and, among the output power from the power storage device, the output power that is derived from renewable energy and the output power that is derived from the purchased power; and a registration request unit that transmits the generated tracking information to a first node of the multiple nodes and requests registration in a distributed ledger.

[0008] One aspect of the present invention is a power management device connected to a blockchain to which a plurality of nodes are connected, and to a power storage device of a consumer facility having the power storage device capable of charging purchased power and power based on renewable energy, the power management device having a power information acquisition unit that acquires measurement results of measuring the power generated by the renewable energy and measurement results of measuring the power output from the power storage device, a tracking information generation unit that, when charging the power storage device, generates tracking information representing, among the charging rates of the power storage device, the charging rate charged in the power storage device derived from renewable energy and the charging rate charged derived from purchased power based on the measurement results obtained by the power information acquisition unit, and a registration request unit that transmits the generated tracking information to a first node of the plurality of nodes and requests registration in a distributed ledger.

[0009] One aspect of the present invention is a power management method executed in a power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of charging purchased power and power based on renewable energy, in which a power information acquisition unit of the power management device acquires measurement results of measuring the power generated by the renewable energy and measurement results of measuring the power output from the storage device, and a tracking information generation unit of the power management device generates tracking information based on the measurement results obtained by the power information acquisition unit when discharging from the storage device, the tracking information including, among the charging rates of the storage device, the charging rate at the storage device that is charged due to renewable energy and the charging rate that is charged due to purchased power, and, among the output power from the storage device, the output power that is derived from renewable energy and the output power that is derived from the purchased power, and a registration request unit of the power management device transmits the generated tracking information to a first node of the plurality of nodes and requests registration in a distributed ledger.

[0010] One aspect of the present invention is a power management method executed in a power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of charging purchased power and power based on renewable energy, in which a power information acquisition unit of the power management device acquires measurement results of measuring the power generated by the renewable energy and measurement results of measuring the power output from the storage device, and a tracking information generation unit of the power management device generates tracking information representing, among the charging rates of the storage device, the charging rate charged in the storage device derived from renewable energy and the charging rate charged derived from purchased power based on the measurement results obtained by the power information acquisition unit when charging the storage device, and a registration request unit of the power management device transmits the generated tracking information to a first node of the plurality of nodes and requests registration in a distributed ledger. Effect of the Invention

[0011] As described above, according to the present invention, power supply tracking is possible even in a system having a power storage device. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic block diagram showing a configuration of a power supply tracking system 1 according to an embodiment of the present invention. [Diagram 2] 2 is a schematic block diagram illustrating the function of a power management device 231. FIG. [Diagram 3] 13 is a flowchart illustrating the operation of the power management device 231. [Figure 4A] FIG. 1 is a diagram illustrating the origin of a storage battery. [Figure 4B] FIG. 1 is a diagram illustrating the origin of a storage battery. [Diagram 5] FIG. 11 is a schematic block diagram showing the configuration of a power source tracking system 1 according to another embodiment. [Figure 6] FIG. 2 is a schematic block diagram illustrating the function of a power management device 231A. [Figure 7] FIG. 13 is a diagram for explaining the case where the present invention is applied to power source tracking in electricity retailing. [Figure 8] FIG. 1 is a schematic block diagram showing a configuration of a power source tracking system 1B. [Figure 9] FIG. 13 is a diagram showing an example of a calculation result of a power management device 231B. [Figure 10] FIG. 13 is a diagram showing an example of a calculation result of a power management device 231B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a power supply tracking system 1 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing the configuration of a power supply tracking system 1 according to an embodiment of the present invention. The power source tracking system 1 includes a blockchain platform 10, a consumer facility 20, a commercial power source 30, and a network 40. The blockchain platform 10 and the customer facility 20 are communicatively connected via a network 40. The customer facility 20 and the commercial power source 30 are connected via a power line.

[0014] ≪10 Blockchain Platforms≫ The blockchain platform 10 includes multiple nodes 101 (node ​​101a, node 101b, node 101c, node 101d, node 101e, and node 101f; hereinafter, simply referred to as nodes 101 unless otherwise specified) that are communicatively connected via a network 102. Each of the multiple nodes 101 is composed of a computer. Each node 101 has a distributed ledger format in which data indicating the power usage status is received at regular intervals from a computer in a customer facility connected to the node, a hash value of the data is calculated, and the hash value is sent to other nodes. By using such blockchain technology, the power usage status at each customer facility is stored without being tampered with.

[0015] In the customer facility 20, a power meter 201, a load 202, a measuring device 203, a photovoltaic (PV) panel 211, a power conditioning subsystem (PCS) 212, a storage battery 221, and a power management device 231 are connected via a cable 241. The cable 241 may include a power line and a communication line.

[0016] ≪Commercial power supply 30≫ The commercial power source 30 supplies electric power generated in a power generation facility of an electric power company. The commercial power source 30 is an example of a source of purchased power.

[0017] <Power Meter 201> The power meter 201 is connected to the commercial power source 30 via a cable 241, measures the power supplied from the commercial power source 30 to the load or the storage battery 221, and transmits the measurement result to the power management device 231 via the cable 241. The power meter 201 may transmit the measurement result to the power management device 231 wirelessly.

[0018] <Load 202> The load 202 is operated by being supplied with at least one of power supplied from the commercial power source 30 , power supplied from the storage battery 221 , and power supplied from the PV panel 211 via the PCS 212 .

[0019] <<Measuring Device 203>> The measurement device 203 measures the power supplied to the load, and outputs the measurement result to the power management device 231 .

[0020] <PV Panel 211> The PV panel 211 is a photovoltaic power generation device that outputs renewable energy obtained by converting sunlight into electric power using a solar cell to the storage battery 221 or the load 202 via the PCS 212 . The PV panel 211 may be a facility installed on the same premises as the load 202, an off-site facility owned by the company, or a facility owned by a renewable energy provider.

[0021] <PCS212> The PCS 212 converts DC power (renewable energy) supplied from the PV panel 211 into AC power and supplies it to a load or the storage battery 221. Here, the PCS 212 may supply AC power to the storage battery 221, or may supply AC power to the storage battery 221. The PCS 212 also has a controller that measures the power obtained from the PV panels 211 and transmits the measurement results to the power management device 231.

[0022] <Storage Battery 221> The storage battery 221 accumulates power supplied from at least one of the power generated by the PV panel 211 and the power supplied from the commercial power source 30, and supplies the accumulated power to the load 202. A controller is provided in the storage battery 221. This controller has a function of measuring the output power output from the storage battery and transmitting the measurement result to the power management device 231, a function of measuring the charging power for charging the storage battery with power supplied from outside (renewable energy or commercial power source) and transmitting the measurement result to the power management device 231, and a function of measuring the SOC of the storage battery 221 and transmitting the measurement result to the power management device 231.

[0023] This storage battery 221 is an example of a power storage device, and other power storage devices may be used as long as they are capable of storing electric power. Examples of other power storage devices include a hydrogen system that stores hydrogen obtained by electrolysis of water and outputs it using a fuel cell during power generation, a flywheel that converts electric energy into the physical energy of rotational motion, stores the converted energy, and converts the physical energy of rotational motion into electric energy during power generation and outputs the converted energy, and a pumped-storage power generation device that uses electric power to pump water to the top and generates power by supplying water from the top during power generation. Furthermore, the storage battery 221 can be charged with power supplied from the PV panel 211, so that it stores renewable energy and supplies it to the load 202 when it needs to be discharged. This allows the consumer facility 20 to use the renewable energy supplied from the PV panel 211 (for example, the load 202) by first charging the storage battery 221 with the renewable energy and then discharging it. In addition, in the customer facility 20, it is also possible to supply the renewable energy supplied from the PV panel 211 to the load 202 without charging the storage battery 221.

[0024] ≪Power management device 231≫ The power management device 231 has the function of determining the origin (whether it is renewable energy or a commercial power source) of the electricity used in the consumer facility 20 (e.g., the load 202), and based on the result of this determination, has the function of adding power tracking information to the charging and discharging power of the storage battery 221 and transmitting it to the blockchain platform 10. By transmitting the power used in the consumer facility 20 from the power management device 231 to the blockchain platform 10, it is possible to notify the blockchain platform 10 of how much of the power used in the consumer facility 20 was covered by power derived from renewable energy. Based on this notification, the blockchain platform 10 electronically stores this information in a distributed ledger, making it possible to use it to prove the environmental value of renewable energy.

[0025] FIG. 2 is a schematic block diagram illustrating the functionality of the power management unit 231. The power management device 231 includes a power information acquisition unit 2311, a tracking information generation unit 2312, a registration request unit 2313, and a storage unit 2314. The power information acquisition unit 2311, the tracking information generation unit 2312, and the registration request unit 2313 may be configured by a processing unit such as a CPU (Central Processing Unit) or a dedicated electronic circuit.

[0026] The power information acquisition unit 2311 acquires purchased power [kW] at time n, load power [kW] at time n, PV power [kW] at time n, storage battery output (positive discharge) [kW] at time n, and SOC measurement value [%] at time n. These variables are as shown in the following (1).

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[0027] The power information acquisition unit 2311 acquires the purchased power [kW] at time n from the power meter 201, the load power [kW] at time n from the measuring device 203, the PV power [kW] at time n from the controller of the PCS 212, and the storage battery output (positive discharge) [kW] at time n and the SOC measurement value [%] at time n from the controller provided in the storage battery 221.

[0028] When storing power in the power storage device or discharging power from the power storage device to the outside, the tracking information generating unit 2312 generates tracking information including the charging rate of the power storage device derived from renewable energy and the charging rate of the power storage device derived from purchased power, based on data obtained from the power information acquiring unit 2311. For example, by using information included in this tracking information, it is possible to know that the current charging rate of the power storage device is 80%, and that, of the charging rate A%, the charging rate of the power storage device derived from renewable energy is A1%, and the charging rate of the power storage device derived from purchased power is A2% (charging rate A=A1+A2). In addition, when discharging electricity from the power storage device, the tracking information generation unit 2312 generates tracking information based on data obtained from the power information acquisition unit 2311, the tracking information including, among the charging rates of the power storage device, the charging rate at the power storage device that is charged due to renewable energy and the charging rate that is charged due to purchased electricity, and, among the output power from the power storage device, the output power that is charged due to renewable energy and the output power that is charged due to purchased electricity.

[0029] The registration request unit 2313 transmits the generated tracking information to a first node among the multiple nodes and requests registration in the distributed ledger. The first node to which the tracking information is transmitted may be any node constituting the block chain platform 10. In this embodiment, a case where the first node is the node 101e will be described.

[0030] The storage unit 2314 stores various information. For example, the storage unit 2314 stores the rated capacity W BAT Memorize. Furthermore, the storage unit 2314 stores the tracking information transmitted from the power management apparatus 231 to the first node. The storage unit 2314 is configured by a storage medium, such as a hard disk drive (HDD), a flash memory, an electrically erasable programmable read only memory (EEPROM), a random access read / write memory (RAM), a read only memory (ROM), or any combination of these storage media. For example, a non-volatile memory can be used for this storage unit 2314.

[0031] Next, the operation of the above-mentioned power management device 231 will be described with reference to the flowchart in Fig. 3. The power management device 231 executes the process shown in this flowchart every time the timing for transmitting tracking information to a node arrives. For example, the power management device 231 transmits tracking information sequentially at a timing that matches the time interval for generating blocks in the blockchain platform 10. The power information acquisition unit 2311 of the power management device 231 acquires purchased power [kW] at time n, load power [kW] at time n, PV power [kW] at time n, storage battery output (positive: discharge, negative: charge) [kW] at time n, and measured SOC value [%] at time n (step S101). The measured SOC value is a value obtained by measuring the SOC (State Of Charge) and is a measurement result obtained by measuring the charging rate.

[0032] Next, the tracking information generating unit 2312 determines whether the storage battery is charging or discharging by determining whether the storage battery output at time n is less than 0 (step S102). For example, if the storage battery output at time n is less than 0, the tracking information generating unit 2312 determines that the storage battery is in a charging state at time n, and if the storage battery output at time n is 0 or more, the tracking information generating unit 2312 determines that the storage battery is in a discharging state. When the tracking information generating unit 2312 determines that the operating state of the storage battery 221 is charging, it calculates the SOC value of the portion of the SOC of the storage battery 221 that is charged due to renewable energy and the SOC value of the portion of the SOC that is charged due to purchased electricity (electricity supplied from the commercial power source 30) (step S103). Here, the tracking information generating unit 2312 calculates by different calculation methods depending on whether the charging power currently being charged to the storage battery 221 is derived entirely from renewable energy or whether at least a part of the charging power is derived from purchased power. When the charging power being charged to the storage battery 221 is entirely from renewable energy, this refers to when all the charging power for charging the storage battery 221 is power generated in the PV panel 211 and supplied via the PCS 212. In other words, this can also be said to be when the storage battery 221 is being charged without being supplied from the commercial power source 30.

[0033] <When all energy comes from renewable sources> Whether the charging power for charging the storage battery 221 is entirely generated and supplied by the PV panel 211 or whether at least a portion of the charging power is derived from purchased power can be determined, for example, by using the following formula (2) or formula (5). The tracking information generating unit 2312 uses the data obtained from the power information acquiring unit 2311, and if the following formula (2) is established, determines that all charging is derived from renewable energy.

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[0034] Here, the storage priority X of the PV power uses any number in the range of 0 to 1. For example, when all the power (PV power) supplied from the PV panel 211 is stored and the surplus is used for the load, X=1 is used, when half of the PV power is stored as much as possible, X=0.5 is used, and when as much of the PV power is directly used for the load as possible and the surplus is stored, X=0 is used. The larger the storage priority X of the PV power, the higher the priority of storing the power in the storage battery 221.

[0035] By using this formula (2), the tracking information generator 2312 obtains a value obtained by dividing the product of the difference between the measured SOC value obtained at the previous time and the measured SOC value obtained at the current time and the rated capacity of the storage battery by the measurement time interval, compares this value with the product of the storage priority of the PV power and the power generated by the PV panel at time n, and if the product is larger, it can be determined that all of the charging power for charging the storage battery 221 is power generated and supplied by the PV panel 211. For example, if the power from the PV panel supplied to the storage side according to the storage priority is greater than the increased SOC at a certain time, it can be determined that all of the power is generated and supplied by the PV panel 211.

[0036] When it is determined that all the power is generated and supplied by the PV panels 211, the tracking information generator 2312 calculates the charging rate derived from renewable energy based on the following formula (3).

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[0037] The initial value of the charging rate derived from renewable energy and the initial value of the charging rate derived from purchased power may be set to a state in which the storage battery 221 is fully charged only with purchased power or only with renewable energy, and a value corresponding to this state may be set as the initial value. Also, the SOC of the storage battery 221 may be set to 0(%), and a value corresponding to this state may be set as the initial value.

[0038] <When at least a portion of the electricity comes from purchased electricity> The tracking information generating unit 2312 uses the data obtained from the power information acquiring unit 2311, and when the following formula (5) is established, determines that at least a portion of the charging is derived from purchased power.

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[0039] By using this formula (5), the tracking information generator 2312 obtains a value obtained by dividing the product of the difference between the measured SOC value obtained at the previous time and the measured SOC value obtained at the current time and the rated capacity of the storage battery by the measurement time interval, compares this value with the product of the storage priority of the PV power and the power generated by the PV panel at time n, and if this value is equal to or greater than this product, determines that at least a part of the charging power for charging the storage battery 221 is derived from purchased power. For example, if the increased SOC at a certain time is equal to or greater than the power from the PV panel supplied to the storage side according to the storage priority, it is determined that at least a part of the charging power is derived from purchased power.

[0040] When it is determined that at least a portion of the power is derived from purchased power, the tracking information generating unit 2312 calculates the charging rate derived from renewable energy based on the following formula (6).

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[0041] When the tracking information generation unit 2312 calculates the SOC based on renewable energy and the SOC derived from purchased electricity, the registration request unit 2313 transmits information including the calculated SOC based on renewable energy and the SOC derived from purchased electricity as tracking information to the first node together with an instruction requesting that the first node register the information in the distributed ledger (step S105). Here, the registration request unit 2313 may transmit information including the purchased power at time n in the consumer facility 20, the load power at time n, the solar power generation output (PV power) at time n, the charging / discharging power (output power) of the storage battery, and the SOC value of the storage battery (SOC derived from PV, SOC derived from purchased power) as tracking information to the first node together with a request for registration in the distributed ledger.

[0042] In step S102, when the tracking information generating unit 2312 determines that the operating state of the storage battery 221 is discharging, it obtains the value of the SOC derived from renewable energy or purchased power and the value of the output power at time n. Here, the tracking information generating unit 2312 calculates the renewable energy at time n based on the following equation (8).

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[0043] In addition, the tracking information generating unit 2312 calculates the value of the SOC derived from the purchased power based on the following formula (9).

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[0044] Moreover, the tracking information generating unit 2312 calculates the output power based on the following equation (10).

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[0045] Moreover, the tracking information generating unit 2312 calculates the output power based on the following equation (11).

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[0046] When the tracking information generating unit 2312 calculates the SOC derived from renewable energy, the SOC derived from purchased power, the output power derived from renewable energy, and the output power derived from purchased power, the registration requesting unit 2313 transmits these as tracking information to the first node together with a command requesting that they be registered in the distributed ledger (step S105). Here, the tracking information generating unit 2312 may transmit information indicating that the storage battery 221 is in a discharging state, the SOC derived from renewable energy, and the SOC derived from purchased power as tracking information. Here, the registration request unit 2313 may transmit information including the purchased power at time n in the consumer facility 20, the load power at time n, the solar power generation output (PV power) at time n, the charging / discharging power (output power) of the storage battery, and the SOC value of the storage battery (SOC derived from PV, SOC derived from purchased power) as tracking information to the first node together with a request for registration in the distributed ledger.

[0047] According to the above-described embodiment, the SOC of the storage battery 221 is calculated as SOC derived from renewable energy and SOC derived from purchased power, and is transmitted to the blockchain platform 10 as tracking information. The transmission of the tracking information is performed every time a timing corresponding to the time interval for generating blocks in the blockchain platform 10 arrives. This makes it possible to know whether the power at the time of increase or decrease in the SOC of the storage battery (during charging and discharging) is derived from renewable energy or derived from purchased power, and when the managed consumer facility includes a power storage device, it becomes possible to know to what extent the power output from the power storage device is derived from renewable energy. Furthermore, by managing the tracking information in the blockchain platform 10, it becomes possible to store and manage the tracking information as ledger information, and therefore it becomes possible to prove the environmental value.

[0048] In addition, since blockchain technology is used, tracking information is less likely to be tampered with. Furthermore, according to the above-described embodiment, it is also possible to manage, as tracking information, a case in which the amount of stored electricity is reduced due to self-discharge in the electricity storage device or a case in which a charge / discharge loss occurs. In the above-described embodiment, if the consumer facility is a system that does not have a power storage device, the power management device 231 may transmit the origin of the power supplied to the load from the photovoltaic power generation output and purchased power to the node as tracking information, and write it on the blockchain.

[0049] In the embodiment described above, even if the power at the time of increase or decrease in the SOC of the storage battery (during charging and discharging) includes power derived from renewable energy (PV) or power derived from purchased power, as shown in Fig. 4A, it is possible to grasp whether the power is derived from renewable energy (PV) or power derived from purchased power. As a result, a case has been described in which the environmental value can be clarified even in a system including a storage battery.

[0050] Next, as another embodiment, as shown in FIG. 4B, a case will be described in which it is possible to prove environmental value even in the case of a system that includes a storage battery by managing which of multiple types of power sources (including commercial grids, renewable energy (PV-derived, wind power), generators, etc.) the power comes from when the SOC of the storage battery increases or decreases (when charging or discharging). That is, in addition to commercial grids and PV power generation, wind power generation, generators, etc. may also be used as power sources. When a storage battery is charged in a system in which various types of power sources are combined, if it is not possible to identify which power source the charged amount of stored electricity comes from: purchased power, PV, wind power generation, or a generator, it becomes difficult to track the power source. Therefore, when multiple types of power sources are used in a system having an energy storage device such as a storage battery, a system that enables power source tracking is required.

[0051] Fig. 5 is a schematic block diagram showing the configuration of a power source tracking system 1 according to another embodiment. In this other embodiment, the same functions as those in the power source tracking system 1 shown in Fig. 1 are denoted by the same reference numerals, and only the different parts will be described. In the power source tracking system 1 shown in FIG. 1, the commercial power source 30, the storage battery 221, and the PV panel 211 are connected to the cable 241, and the storage battery 221 can be charged from the commercial power source 30 and the PV panel 211. However, in this other embodiment, in addition to the commercial power source 30, the storage battery 221, and the PV panel 211, the power sources of a wind power generation device 222 and a generator 225 are also connected to the cable 241, and the storage battery 221 can be charged from the commercial power source 30, the PV panel 211, the wind power generation device 222, and the generator 225.

[0052] The wind power generation device 222 receives wind power to rotate a windmill, and converts the motive power into electric power using a generator to obtain renewable energy, which is output to the storage battery 221 or the load 202. The measurement device 223 measures the electric power generated by the wind power generation device 222, and outputs the measurement result to the power management device 231A. The generator 225 outputs the electric power obtained by generating electric power to the storage battery 221 or the load 202. The measurement device 226 measures the electric power generated by the generator 225, and outputs the measurement result to the power management device 231A.

[0053] Here, the power sources that can be charged into the storage battery 221 are described as being the commercial power source 30, the PV panel 211, the wind power generation device 222, and the generator 225, but are not limited to these, and the storage battery 221 can be charged from the first to mth power sources m, which can include purchased power, power based on renewable energy, and power obtained from a generator. For example, the power source for charging the storage battery 221 may be power based on a plurality of renewable energies. In this case, the power source may be, for example, the PV panel 211 and the wind power generation device 222. Also, for example, the power source for charging the storage battery 221 may be power based on one or more renewable energies and power other than one or more renewable energies. In this case, the power based on renewable energy may be a plurality of power sources (the PV panel 211 and the wind power generation device 222), and the power other than the power based on renewable energy may be a single power source (for example, the commercial power source 30). Also, for example, the power based on renewable energy may be a single power source (the PV panel 211), and the power other than the power based on renewable energy may be a plurality of power sources (the commercial power source 30 and two or more generators 225, etc.). Also, for example, the power based on renewable energy may be a plurality of power sources (the plurality of PV panels 211 and the wind power generation device 222), and the power other than the power based on renewable energy may be a plurality of power sources (the commercial power source 30, the plurality of generators 225). Also, for example, the power source that charges the storage battery 221 may be power other than the power based on the multiple renewable energies. In this case, the power other than the power based on the multiple renewable energies may be the commercial power source 30 and the generator 225.

[0054] FIG. 6 is a schematic block diagram illustrating the function of the power management unit 231A. The power management device 231A includes a power information acquisition unit 2311A, a tracking information generation unit 2312A, a registration request unit 2313, and a storage unit 2314. The power information acquisition unit 2311A, the tracking information generation unit 2312A, and the registration request unit 2313 may be configured by a processing unit such as a CPU (Central Processing Unit) or a dedicated electronic circuit. The registration request unit 2313 and the storage unit 2314 have the same functions as the registration request unit 2313 and the storage unit 2314 shown in FIG.

[0055] The power information acquisition unit 2311A acquires the battery charge / discharge power amount (positive discharge) [kWh] from time n-1 to n, the battery charge / discharge power amount (positive discharge) [kWh] from power source m from time n-1 to n, the battery SOC value (measured value) [%] at time n, the battery SOC value (calculated value) [%] from power source m at time n, and the SOC measurement value [%] at time n. These variables are as shown in the following (12).

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[0056] Here, the power information acquiring unit 2311A can obtain the storage battery charge / discharge power amount (positive discharge) [kWh] from time n-1 to time n based on the following formula (13).

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[0057] Moreover, the power information acquiring unit 2311A can obtain the storage battery SOC value (measured value) [%] at time n from the following formula (14).

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[0058] The power information acquisition unit 2311A acquires the power supplied from the power source m to the storage battery 221 from a measurement device provided at the power source m during charging of the storage battery 221, with respect to the amount of storage battery charge / discharge power (positive discharge) [kWh] derived from the power source m at times n-1 to n. For example, in this example, the power source m is four (m=4), namely, the commercial power source 30, the PV panel 211, the wind power generation device 222, and the generator 225. The power supplied from the commercial power source 30 to the storage battery 221 is obtained from the measurement value of the power meter 201. The power supplied from the PV panel 211 to the storage battery 221 is obtained from the measurement value of the PCS 212. The power supplied from the wind power generation device 222 to the storage battery 221 is obtained from the measurement value of the measurement device 223. The power supplied from the generator 225 to the storage battery 221 is obtained from the measurement value of the measurement device 226.

[0059] When the storage battery 221 is being charged, the power information acquiring unit 2311A obtains the battery SOC value (calculated value) [%] derived from the power source m at time n based on the following formula (15). Also, when the storage battery 221 is being discharged, the power information acquiring unit 2311A can obtain the battery SOC value (calculated value) [%] derived from the power source m at time n based on the following formula (15).

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[0060] Here, the power information acquisition unit 2311A calculates the amount of battery charge / discharge power (positive discharge) [kWh] derived from the power source m at times n-1 to n, when the storage battery 221 is discharging, based on the following formula (16).

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[0061] In addition, the power information acquisition unit 2311A can calculate the average instantaneous power of each power source m from time n-1 to n by dividing the battery charge / discharge power amount (positive discharge) [kWh] from the power source m at time n, which is obtained by the above equation (16), by Δt.

[0062] Here, in the case of the storage battery 221, when self-discharge or an error in measuring the SOC occurs, the SOC fluctuates even though the battery 221 is neither charged nor discharged. In this case, the power information acquisition unit 2311A can make a correction based on the following formula (17).

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[0063] At time n, when charging power to the storage device and discharging power from the storage device to the outside, the tracking information generation unit 2312A calculates the amount of power output from each of the power sources m, the amount of charging and discharging power of the storage device, and the SOC value of the storage battery based on the data obtained from the power information acquisition unit 2311A, and generates tracking information including the amount of power output from each of the power sources m, the amount of charging and discharging power of the storage device, and the SOC value of the storage battery. This allows the origin of multiple power sources m to be added to the SOC of the power storage device. For example, by using the information included in this tracking information, it is possible to know that the current charging rate of the power storage device is 80%, and of the charging rate A%, the charging rate in the power storage device originating from the PV panel 211 is A1%, the charging rate originating from the wind power generation device 222 is A2%, the charging rate originating from the commercial power source 30 is A3%, and the charging rate originating from the generator 225 is A4% (charging rate A=A1+A2+A3+A4). Such tracking information is transmitted every time the timing for transmitting a block to the blockchain platform arrives.

[0064] In the above-mentioned power source tracking system 1A, the case where power source tracking within a building is assumed has been described as an example, but as shown in Fig. 7, it can also be applied to power source tracking of electricity retailing. In this case, it is possible to know from which power source m the retailed electricity comes and to what extent.

[0065] According to the other embodiment described above, even in a system including an energy storage device, tracking of each of a plurality of power sources m becomes possible, and environmental value certification of renewable energy becomes possible.

[0066] Next, another embodiment will be described. In the power source tracking system 1A of FIG. 5, when controlling charging and discharging of a power storage device, a case has been described in which, when charging the power storage device, the power storage device is charged from an arbitrary power source based on rules set by a retailer, and when discharging the power storage device, the power storage device is discharged evenly according to the immediately preceding charging state (the ratio of each power source to the total remaining charge). There are other ways of discharging besides discharging evenly. For example, a user may wish to preferentially use a specific power source among multiple power sources when charging and discharging. In such a case, by adopting the following configuration, tracking information can be generated even when multiple power storage devices are charged or discharged according to the priority order.

[0067] FIG. 8 is a schematic block diagram showing the configuration of a power source tracking system 1B according to another embodiment. In this figure, in the power source tracking system 1B, a plurality of power sources, a load, and a storage battery are connected to a cable 241B. Although not shown in this figure, the power source tracking system 1B is provided with a power meter, a measuring device, a blockchain platform, a node, and the like in the same manner as in Figures 1 and 5. The power supplied from each of the multiple power sources to the storage battery 221 is measured by a measuring device, similar to the power source tracking system 1A shown in Fig. 5, and the measurement result is output to the power management device 231B. This allows the power management device 231B to grasp the power supplied from each power source to the storage battery 221.

[0068] Here, four power sources, namely power source 1, power source 2, power source 3, and power source 4, are connected as multiple power sources, and different types of power sources are used for each of them. For example, a commercial power source, a PV panel, a wind power generation device, a generator, etc. can be used. The storage battery 221 can be charged using power supplied from the power source 1, the power source 2, the power source 3, and the power source 4 during charging, and supplies power to the load 202B during discharging. The load 202B is operated by power supplied from any one of the power source 1, the power source 2, the power source 3, the power source 4, and the storage battery 221.

[0069] The power management device 231B has the functions of the power management device 231 or the power management device 231A, and can calculate the amount of charge or discharge from each power source in the storage battery 221 when charging or discharging is performed in accordance with the priority order set for the multiple power sources.

[0070] Definition of variables and constants Here, the variables are as shown in (18) below.

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[0071] Definition of variables and constants The power management device 231B first ΔC=C t -C t-Δt Calculate where C t is obtained by measuring the remaining capacity of the storage battery 221 using a controller provided in the storage battery 221. When ΔC is obtained, the power management device 231B performs a calculation according to the obtained value of ΔC.

[0072] <When ΔC=0> The case of ΔC=0 corresponds to the case where the remaining capacity of the storage battery 221 remains unchanged. In this case, the power management device 231B calculates the remaining battery capacity from the power source n at time t based on the following equation (19).

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[0073] <When ΔC>0> When ΔC>0, this corresponds to a case where the remaining capacity of the storage battery 221 has increased. In this case, the power management device 231B determines the charging priority order for the power received from power source 1, power source 2, power source 3, and power source 4. For example, the order of priority may be power source 4, power source 3, power source 2, and power source 1, with power source 4 being given the highest priority. These priorities may be stored in advance in a storage unit of the power management device 231B, and the priorities may be determined based on the priorities that have been read out. For example, if the order of priority is power supply 4, power supply 3, power supply 2, and power supply 1, the order can be expressed using the variables as shown in (20) below.

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[0074] Once the priorities have been determined, the power management unit 231B performs the following calculations based on the determined priorities.

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[0075] The tracking information generating unit of the power management device 231B subtracts the capacity when the storage battery is charged with power supplied from the power source with the highest priority from the change in the total remaining capacity of the storage battery 221. Next, the tracking information generating unit subtracts the capacity when the storage battery is charged with power obtained from the power source with the next highest priority from the change in the total remaining capacity after subtraction. This calculation is repeated in order until the power source with the lowest priority is reached. The power supplied from the power source to the storage battery can be obtained from a measuring device. When the power management device 231B completes the calculation for each power source according to the priority order, ΔC=0. However, there may be cases where ΔC>0 due to a loss of received power data, etc. In this case, the power management device 231B allocates the remaining battery power from a pre-specified power source (for example, a commercial power source). This makes it possible to determine how much of the power that has been charged into the storage battery 221 has been charged and from which power source.

[0076] The tracking information generating unit of the power management device 231B can obtain information indicating how much power was supplied from each power source by calculating the charging power derived from each power source based on the ΔC obtained in this manner. When charging the storage battery 221 with power at time t, the tracking information generation unit uses this to calculate the amount of power output from each of the power sources n, the amount of power charged and discharged from the power storage device, and the SOC value of the storage battery based on the data obtained from the power information acquisition unit, and generates tracking information including the amount of power output from each of the power sources n, the amount of power charged and discharged from the storage battery 221, and the SOC value of the storage battery. This allows multiple power source origins to be assigned to the SOC of the storage battery 221. Such tracking information is transmitted every time it is time to transmit a block to the blockchain platform.

[0077] <When ΔC<0> When ΔC<0, this corresponds to a case where the remaining capacity of the storage battery 221 has decreased. In this case, the power management device 231B determines the discharge priority order for the remaining battery powers from the power source 1, the power source 2, the power source 3, and the power source 4. For example, the order of priority may be power source 1, power source 2, power source 3, and power source 4, with the highest priority being given to discharging power charged by power source 1. These priorities may be stored in advance in a storage unit of the power management device 231B, which may then be read out and the order of priority determined based on the read out priorities. For example, if the order of priority is power source 1, power source 2, power source 3, and power source 4, the order can be expressed using the variables as shown in (22) below.

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[0078] Once the priorities have been determined, the power management unit 231B performs the following calculations based on the determined priorities.

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[0079] The tracking information generating unit of the power management device 231B subtracts the capacity discharged to the load from the capacity charged from the power source with the highest priority from the change in the total remaining capacity of the storage battery 221, and subtracts the capacity discharged to the load from the capacity charged from the power source with the next highest priority from the change in the total remaining capacity after subtraction, and performs this calculation in order until the power source with the lowest priority is reached. Here, when switching from charging to discharging, the remaining battery capacity from the power source n at time t may be a value calculated using the above formula (21) during charging and immediately before switching from charging to discharging. When the power management device 231B completes the calculation for each power source in accordance with the priority order, ΔC=0 (always becomes 0 due to the calculation specifications). This makes it possible to determine from which power source the remaining battery power of the power discharged from the storage battery 221 to the load is derived.

[0080] The tracking information generating unit of the power management device 231B can obtain information indicating from which power source the charging power was discharged (supplied to the load) by calculating the discharge power originating from each power source based on the ΔC obtained in this manner. Using this, when discharging from the storage battery 221 at time t, the tracking information generation unit calculates the amount of power output from each of the power sources n, the amount of charge / discharge power of the storage device (the discharge power indicating which power source the charging power is from), and the SOC value of the storage battery, and generates tracking information including the amount of power output from each of the power sources n, the amount of charge / discharge power of the storage battery 221 (the discharge power indicating which power source the charging power is from), and the SOC value of the storage battery. This allows multiple power source origins to be assigned to the SOC of the storage battery 221. Such tracking information is transmitted every time it is time to transmit a block to the blockchain platform.

[0081] 9 and 10 are diagrams showing examples of calculation results of the power management device 231B in this embodiment. Fig. 9 shows the time series of power transition, and Fig. 10 shows the time series of the remaining battery charge. The conditions are charging at 180 kW from 7:00 to 14:00, and discharging at 50 kW from 19:00 to 23:30. The charging priority order is power source 4 > power source 3 > power source 2 > power source 1 (power source 4 has the highest priority), and the discharging priority order is power source 1 > power source 2 > power source 3 > power source 4 (power source 1 has the highest priority). Referring to Figure 10, it can be seen that the remaining battery power increases in the order of c4, c3, and c2 during charging. It can also be seen that the remaining battery power is consumed first in the order of c1, c2 during discharging.

[0082] The power management device 231 in the above-described embodiment may be realized by a computer. In this case, a program for realizing this function may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed to realize the function. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. The term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into a computer system. The term "computer-readable recording medium" may also include a medium that dynamically holds a program for a short period of time, such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line, and a medium that holds a program for a certain period of time, such as a volatile memory inside a computer system that is a server or client in such a case. The above-described program may be a program for realizing a part of the above-described function, or may be a program that can realize the above-described function in combination with a program already recorded in the computer system, or may be a program that is realized using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0083] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included. [Explanation of symbols]

[0084] 1, 1A, 1B...power source tracking system, 10...blockchain platform, 20...customer facility, 30...commercial power source, 40...network, 101, 101a, 101b, 101c, 101d, 101e, 101f...node, 102...network, 201...power meter, 202...load, 203, 223, 226...measuring device, 211...PV panel, 221...storage battery, 222...wind power generation device, 225...generator, 231, 231A, 231B...power management device, 241...cable, 2311, 2311A...power information acquisition unit, 2312, 2312A...tracking information generation unit, 2313...registration request unit, 2314...storage unit

Claims

1. A power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of storing purchased power and power based on renewable energy, a power information acquisition unit that acquires a measurement result of the power generated by the renewable energy and a measurement result of the power output from the power storage device; When charging the power storage device, based on the measurement result obtained by the power information acquisition unit, The charging rate of the storage device is: A charging rate at which the storage device is charged using renewable energy; and The charging rate derived from purchased electricity, A tracking information generating unit that generates tracking information representing the a registration request unit that transmits the generated tracking information to a first node among the plurality of nodes and requests registration in a distributed ledger; having When the power storage device is charged, the tracking information generation unit When all energy used to charge the storage device is renewable, The charging rate derived from renewable energy is calculated based on the following formula (1): The charging rate derived from the purchased power is calculated based on the following formula (2): When charging the power storage device with at least purchased power, The charging rate derived from renewable energy is calculated based on the following formula (3): The charging rate derived from purchased power is calculated based on the following formula (4). Power management device. [0010]

2. A power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of storing purchased power and power based on renewable energy, a power information acquisition unit that acquires a measurement result of the power generated by the renewable energy and a measurement result of the power output from the power storage device; When charging the power storage device, based on the measurement result obtained by the power information acquisition unit, The charging rate of the storage device is: A charging rate at which the storage device is charged using renewable energy; and The charging rate derived from purchased electricity, A tracking information generating unit that generates tracking information representing the a registration request unit that transmits the generated tracking information to a first node among the plurality of nodes and requests registration in a distributed ledger; having When discharging from the power storage device, the tracking information generation unit The charging rate derived from renewable energy is calculated based on the following formula (5): The charging rate derived from purchased power is calculated based on the following formula (6). Power management device. [0025]

3. A power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of storing purchased power and power based on renewable energy, a power information acquisition unit that acquires a measurement result of the power generated by the renewable energy and a measurement result of the power output from the power storage device; When charging the power storage device, based on the measurement result obtained by the power information acquisition unit, The charging rate of the storage device is: A charging rate at which the storage device is charged using renewable energy; and The charging rate derived from purchased electricity, A tracking information generating unit that generates tracking information representing the a registration request unit that transmits the generated tracking information to a first node among the plurality of nodes and requests registration in a distributed ledger; having When discharging from the power storage device, the tracking information generation unit Regarding the output power from the power storage device, The output power derived from renewable energy is calculated based on the following formula (7): The output power derived from the purchased power is calculated based on the following formula (8). Power management device. [0030]

4. A power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of storing purchased power and power based on renewable energy, a power information acquisition unit that acquires a measurement result of the power generated by the renewable energy and a measurement result of the power output from the power storage device; When charging the power storage device, based on the measurement result obtained by the power information acquisition unit, The charging rate of the storage device is: A charging rate at which the storage device is charged using renewable energy; and The charging rate derived from purchased electricity, A tracking information generating unit that generates tracking information representing the a registration request unit that transmits the generated tracking information to a first node among the plurality of nodes and requests registration in a distributed ledger; having the power storage device is capable of being charged from first to m-th power sources m, which may include the purchased power, the power based on the renewable energy, and power obtained from a generator; When the power storage device is charged, the tracking information generation unit The charging rate from the power source m at time n is calculated based on the following formula (9). Power management device. [0045]

5. A power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of storing purchased power and power based on renewable energy, a power information acquisition unit that acquires a measurement result of the power generated by the renewable energy and a measurement result of the power output from the power storage device; When charging the power storage device, based on the measurement result obtained by the power information acquisition unit, The charging rate of the power storage device is: A charging rate at which the storage device is charged using renewable energy; and The charging rate derived from purchased electricity, A tracking information generating unit that generates tracking information representing the a registration request unit that transmits the generated tracking information to a first node among the plurality of nodes and requests registration in a distributed ledger; having the power storage device is capable of being charged from first to m-th power sources m, which may include the purchased power, the power based on the renewable energy, and power obtained from a generator; When discharging from the power storage device, the tracking information generation unit The charging rate and discharge power from the power source m at time n are calculated based on the following formula (10). Power management device. [0050]

6. A power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of storing purchased power and power based on renewable energy, a power information acquisition unit that acquires a measurement result of the power generated by the renewable energy and a measurement result of the power output from the power storage device; When charging the power storage device, based on the measurement result obtained by the power information acquisition unit, The charging rate of the power storage device is: A charging rate at which the storage device is charged using renewable energy; and The charging rate derived from purchased electricity, A tracking information generating unit that generates tracking information representing the a registration request unit that transmits the generated tracking information to a first node among the plurality of nodes and requests registration in a distributed ledger; having The power storage device can be charged from a plurality of power sources that may include the purchased power, the power based on the renewable energy, and the power obtained from a generator, and the power storage device is charged in an order of priority with respect to which power source the charging is to be performed from; When the power storage device is charged, the tracking information generation unit From the change in the total remaining charge of the storage battery, subtract the capacity when the storage battery is charged with power supplied from the power source with the highest priority, and from the change in the total remaining charge after subtraction, subtract the capacity when the storage battery is charged with power obtained from the power source with the next highest priority. This calculation is repeated in order until the power source with the lowest priority is reached. Generate tracking information based on the results of the calculations. Power management device.

7. A power management device connected to a blockchain to which a plurality of nodes are connected and to a power storage device of a consumer facility having the power storage device capable of storing purchased power and power based on renewable energy, a power information acquisition unit that acquires a measurement result of the power generated by the renewable energy and a measurement result of the power output from the power storage device; When charging the power storage device, based on the measurement result obtained by the power information acquisition unit, The charging rate of the storage device is: A charging rate at which the storage device is charged using renewable energy; and The charging rate derived from purchased electricity, A tracking information generating unit that generates tracking information representing the a registration request unit that transmits the generated tracking information to a first node among the plurality of nodes and requests registration in a distributed ledger; having The power storage device is capable of being charged from a plurality of power sources that may include the purchased power, the power based on the renewable energy, and the power obtained from a generator, and the power storage device is configured to discharge the power from a power source in an order according to a priority order; When charging from the power storage device, the tracking information generation unit From the change in the total remaining capacity of the storage battery, subtract the capacity discharged to the load from the storage battery capacity charged from the power source with the highest priority, and from the change in the total remaining capacity after subtraction, subtract the capacity discharged to the load from the storage battery capacity charged from the power source with the next highest priority, and repeat this calculation in order until the power source with the lowest priority is reached; Generate tracking information based on the results of the calculations. Power management device.

8. When the storage device is not being discharged or charged, if there is a change in the charging rate of the storage device, the charging rate is corrected based on the following formula (11): The power management device according to claim 4 or 5. [006]

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