Power management system, power management method, and program

Abstract

A power management system according to the present invention, in which charges per unit that are different from each other are respectively set for first purchased power that is supplied to a first electric device and second purchased power that is supplied to a second electric device, comprises: a first acquisition unit (for example, acquisition unit (71)) that acquires, from a first measurement device to which a distributed power supply and the first electric device are electrically connected, a first power value obtained by measuring power in the reverse power flow from the distributed power supply to an electric power system; a second acquisition unit (for example, acquisition unit (71)) that acquires, from a power meter which is electrically connected to the second electric device, a second power value obtained by measuring power in a forward power flow from the electric power system; and a calculation unit (72) that, on the basis of smaller one of the first power value and the second power value, calculates at least one of the amount of purchased power from the electric power system and the amount of power sold to the electric power system.

Description

Technical Field

[0001] The present invention relates to a power management system, a power management method, and a program.

Background Art

[0002] Conventionally, there is known a method of separately measuring power consumption by connecting a plurality of power meters in a parent-child connection and performing differential metering to separate normal power loads and power loads to which dynamic pricing is applied (see Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technology of Non-Patent Document 1, when there is a distributed power source (self-generation equipment) such as a solar cell in a facility such as a house, there is a problem that the amount of self-consumption of generated power is also measured as the amount of purchased power. In addition, it may be desirable to accurately calculate the amount of power sold.

[0005] Therefore, the present invention provides a power management system, a power management method, and a program capable of accurately calculating at least one of the amount of purchased power and the amount of power sold when there is a distributed power source in a facility.

Means for Solving the Problems

[0006] A power management system according to one aspect of the present disclosure is a power management system for managing the power of a first electrical device and a second electrical device, wherein different unit prices are set for the first purchased power supplied to the first electrical device and the second purchased power supplied to the second electrical device, and the power management system comprises: a first acquisition unit that acquires a first power value measured from a first measuring instrument electrically connected to a distributed power source and the first electrical device, which measures the power flowing in reverse from the distributed power source to the power grid; a second acquisition unit that acquires a second power value measured from a second measuring instrument electrically connected to the second electrical device, which measures the power flowing in forward from the power grid; and a calculation unit that calculates at least one of the amount of electricity purchased from the power grid and the amount of electricity sold to the power grid based on the smaller of the first power value and the second power value.

[0007] A power management method according to one aspect of the present disclosure is a power management method executed by a power management system that manages the power of a first electrical device and a second electrical device, wherein different unit prices are set for the first purchased power supplied to the first electrical device and the second purchased power supplied to the second electrical device, and the power management method obtains a first power value from a first measuring instrument electrically connected to the distributed power source and the first electrical device, which measures the power flowing in reverse from the distributed power source to the power grid, and obtains a second power value from a second measuring instrument electrically connected to the second electrical device, which measures the power flowing in forward from the power grid, and calculates at least one of the amount of electricity purchased from the power grid and the amount of electricity sold to the power grid based on the smaller of the first power value and the second power value.

[0008] One aspect of this disclosure is a program that causes a computer to execute the power management method described above. [Effects of the Invention]

[0009] According to one aspect of this disclosure, when there are distributed power sources within a facility, it is possible to realize a power management system that can accurately calculate at least one of the amount of electricity purchased and the amount of electricity sold. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a diagram showing the configuration of a power management system according to an embodiment. [Figure 2] Figure 2 is a block diagram showing the functional configuration of the control device according to the embodiment. [Figure 3] Figure 3 is a flowchart showing the operation of the control device according to the embodiment. [Figure 4] Figure 4 shows a first application example of the power management system according to the embodiment. [Figure 5] Figure 5 shows a second application example of the power management system according to the embodiment. [Figure 6] Figure 6 is a diagram illustrating the method for calculating the exchangeable power in a second application example of the power management system according to the embodiment. [Figure 7] Figure 7 shows a third application example of the power management system according to the embodiment. [Figure 8] Figure 8 shows a fourth application example of the power management system according to the embodiment. [Figure 9] Figure 9 shows a fifth application example of the power management system according to the embodiment. [Figure 10] Figure 10 shows a sixth application example of the power management system according to the embodiment. [Figure 11] Figure 11 shows the configuration of a power management system according to a modified embodiment. [Figure 12] Figure 12 shows a first application example of a power management system according to a modified embodiment. [Figure 13] Figure 13 shows a second application example of the power management system according to a modified embodiment. [Modes for carrying out the invention]

[0011] (Background leading to the present invention) Before describing the present invention, the background leading to it will be explained.

[0012] As a tariff system for electricity use in facilities such as houses, there is a tariff system (DP) called dynamic pricing in which the tariff unit price (electricity unit price) changes according to time. DP is a mechanism that flexibly varies the price according to the demand and supply situation. In particular, in recent years, a DP tariff plan that links the electricity unit price (DP unit price) by DP to the spot price in the electricity retail market has attracted attention.

[0013] However, increasing or decreasing the electricity demand associated with real life according to changes in the DP unit price (for example, saving electricity during price hikes, etc.) imposes a burden on users. Therefore, it may be desirable to set only the power loads that are not directly linked to the electricity demand associated with real life, such as the power consumption of an electric water heater and the charging power of an electric vehicle, as DP, and use the conventional electricity tariff system for other electricity consumption. Taking an electric water heater as an example, it only needs to perform a boiling operation until hot water is used, and since the timing of boiling does not affect the user, it is possible to reduce the electricity bill by automatically boiling at a time when the DP price is low. In addition, the power load directly linked to the electricity demand means the power load that consumes power by operating the user's electrical equipment (for example, turning on the air conditioner).

[0014] In this case, it is necessary to separately measure the power consumption of the normal power load and the power load to which DP is applied, and the method disclosed in Non-Patent Document 1 has been proposed.

[0015] Here, as described in "Problems to be Solved by the Invention," in the method of Non-Patent Document 1, when there is a distributed power source in the facility, there is a problem that the self-consumption portion of the generated power is also measured as purchased power. For example, when supplying power (i.e., self-consuming) from a photovoltaic power generation device (e.g., solar cell 10 and power conversion system 20 shown in FIG. 1 described later), which is an example of a distributed power source, to a power load to which DP is applied, in the technology of Non-Patent Document 1, the purchased power of DP and the self-consumed power are mixed and measured. Therefore, even when there is a distributed power source in the facility, it may be desirable to separately measure the purchased power and the self-consumption portion. Also, it may be desirable to accurately calculate the power sold, which can vary according to the purchased power.

[0016] Therefore, the inventors of the present application have intensively studied, for example, a power management system capable of accurately calculating at least one of the purchased power amount and the sold power amount when there is a distributed power source in the facility, and capable of separating the purchased power and the self-consumption portion, and have devised the power management system and the like described below.

[0017] Hereinafter, embodiments and the like will be specifically described with reference to the drawings.

[0018] Note that the embodiments and the like described below are all illustrative of comprehensive or specific examples. The numerical values, shapes, components, arrangement positions and connection forms of the components, steps, order of steps, etc. shown in the following embodiments are merely examples and are not intended to limit the present invention.

[0019] Also, each figure is a schematic diagram and is not necessarily drawn precisely. Therefore, for example, the scales in each figure do not necessarily match. Also, in each figure, substantially the same components are denoted by the same reference numerals, and duplicate explanations are omitted or simplified.

[0020] Furthermore, in this specification, terms indicating relationships between elements such as "same," as well as numerical values ​​and numerical ranges, do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent (or about 10%).

[0021] Furthermore, in this specification, ordinal numbers such as "first," "second," etc., do not mean the number or order of components unless otherwise specified, but are used to avoid confusion and to distinguish similar components.

[0022] Furthermore, the "connection" of each component refers to an electrical connection, and includes not only cases where two components are directly connected, but also cases where two components are indirectly connected with another component inserted between them.

[0023] (Embodiment) The power management system according to this embodiment will be described below with reference to Figures 1 to 10.

[0024] [1. Configuration of the power management system] First, the configuration of the power management system 1 according to this embodiment will be explained with reference to Figures 1 and 2. Figure 1 is a diagram showing the configuration of the power management system 1 according to this embodiment.

[0025] As shown in Figure 1, the power management system 1 is a system for managing the power of a first electrical device (e.g., a home appliance 51) and a second electrical device (e.g., a charger 52).

[0026] The power management system 1 comprises a solar cell 10 (shown as "PV" in Figure 1), a power conversion system 20 (shown as "PCS" in Figure 1), a storage battery 30 (shown as "SB" in Figure 1), power meters 41 and 42 (shown as "M1" and "M2" in Figure 1), household appliances 51, a charger 52, current sensors 61 and 62 (shown as "CT1" and "CT2" in Figure 1), a management device 70, and a power meter 200 (shown as "M0" in Figure 1), all located in a house 100, and a power grid 300. Household appliances 51 and charger 52 are examples of electrical equipment that generates electricity demand. The power management system 1 only needs to include the management device 70.

[0027] Housing 100 is an example of a facility. A facility may be a residential facility or a non-residential facility. Examples of residential facilities include detached houses and apartment buildings. Each of the multiple dwelling units in an apartment building may be considered a "facility," or the entire apartment building may be considered a "facility." Examples of non-residential facilities include shops, office buildings, schools, welfare facilities, mixed-use commercial facilities, hospitals, and factories.

[0028] Furthermore, it is assumed that the customer in residence 100 has a contract with the retail electricity provider to pay electricity charges based on the electricity measured by electricity meter 41 using the conventional electricity rate system (fixed electricity unit price), and electricity charges based on the electricity measured by electricity meter 42 using a dynamic pricing electricity rate system (DP unit price). In addition, for example, it is assumed that the retail electricity provider has a contract to purchase the electricity sold by electricity meter 41 from the customer.

[0029] Solar cell 10 is a power device that converts light energy into electrical energy (electricity) using the photovoltaic effect. Solar cell 10 is an example of a distributed power source.

[0030] The power conversion system 20, also called a power conditioner, converts the DC power generated by the solar cell 10 into AC power. The power conversion system 20 may also acquire measured values ​​from current sensors 61 and 62 in order to have the storage battery 30 perform the environmentally friendly operation described below.

[0031] The battery 30 is a device capable of charging and discharging, such as a household battery. The battery 30 can operate in environmentally friendly mode. Environmentally friendly mode means that when the measured current of the power meter 200 is positive (forward current) (when electricity is being purchased), the battery 30 discharges to reduce this current (to reduce purchased power), and when the measured current is negative (reverse current) (when reverse current is being sold), the battery 30 charges to reduce this current (to reduce reverse current sales). Environmentally friendly mode means that the battery 30 charges and discharges in a way that brings the measured power at the power meter 200 closer to zero. The measured current of the power meter 200 can be obtained, for example, based on the measurement results of current sensors 61 and 62.

[0032] The power meter 41 is a power sensor that measures the power supplied to the home appliance 51 (power value W1_b shown in Figure 1). The power meter 41 measures, for example, the circulating power supplied from the power grid 300 to the home appliance 51 (i.e., purchased under the conventional electricity rate system). If the generated power (PV power) produced by the solar cell 10 is not shared (supplied) to the home appliance 51, the power meter 41 measures only the circulating power supplied from the power grid 300 to the home appliance 51 (circulating power = power value W1_b). The circulating power here (hereinafter also referred to as purchased power) is the power that is subject to billing in order to calculate the electricity rate under the conventional electricity rate system.

[0033] Furthermore, part or all of the PV power generated by the solar cell 10 is sold to the power grid 300 (retail electricity provider), etc., via the power meter 41. For example, the power meter 41 also measures the power to be sold (power value W1_s shown in Figure 1). The power meter 41 is electrically connected to both the solar cell 10 and the home appliance 51. The power meter 41 may be a conventional (analog) power meter or a so-called smart meter. A smart meter is a power meter that measures electricity usage at a shorter interval than a conventional meter (for example, every 30 minutes) and has a communication function. The power meter 41 is an example of a first measuring instrument.

[0034] The power meter 42 is a power sensor that measures the power supplied to the charger 52 (power value W2_b shown in Figure 1). The power meter 42 measures, for example, the tide power supplied from the power grid 300 to the charger 52 (i.e., purchased under a dynamic pricing electricity rate system). If the PV power generated by the solar cell 10 is not bribed (supplied) to the charger 52, the power meter 42 measures only the tide power supplied from the power grid 300 to the charger 52 (tide power = power value W2_b). If the PV power generated by the solar cell 10 is bribed (supplied) to the charger 52, the power meter 42 measures the total power of the tide power supplied from the power grid 300 to the charger 52 and the bribed power Y (tide power + bribed power Y = power value W2_b). Here, tide power (hereinafter also referred to as purchased power) is the power subject to billing for calculating electricity charges under a dynamic pricing electricity rate system. Furthermore, it is not possible to measure the forward power and the circulating power Y separately using the power meter 42.

[0035] The power meter 42 is electrically connected to the power meter 200 and the charger 52. For example, the power meter 42 is connected only to the charger 52. Connecting only to the charger 52 means that it is connected in a way that allows it to measure only the power supplied to the charger 52, and for example, it means that it is connected to the charger 52 without going through other power meters. The power meter 42 may be a conventional power meter or a so-called smart meter. The power meter 42 is an example of a second measuring instrument.

[0036] The home appliance 51 is an electrical appliance that consumes electricity and is installed in the house 100. The home appliance 51 is an appliance that generates electricity demand and is an example of a first electrical appliance. The first electrical appliance can be any power load that is directly linked to the electricity demand associated with daily life, for example, home appliances 51 such as air conditioners, refrigerators, and televisions are examples, but it may also include other electrical appliances other than home appliances 51.

[0037] For the first electrical appliance, the conventional electricity pricing system will be applied, meaning a fixed electricity unit price will not be applied, and dynamic pricing will not be applied. The fixed electricity unit price will not change depending on the supply and demand situation of electricity, and will be set in advance, for example, at the time of contract.

[0038] Charger 52 is a charging facility (or charging / discharging facility) for charging batteries installed in vehicles that can run on electricity, such as EVs (Electric Vehicles) and PHEVs (Plug-in Hybrid Electric Vehicles), and is an example of a second electrical device. The second electrical device is a power load that is not directly linked to the electricity demand associated with daily life, and may be, for example, an electric water heater. The DP unit price is applied to the second electrical device.

[0039] In this manner, different electricity rates (charge rates) are set for the purchased electricity supplied to the first electrical equipment (first purchased electricity) and the purchased electricity supplied to the second electrical equipment (second purchased electricity). The number of first and second electrical equipment units included in the power management system 1 is not particularly limited and can be one or more. In addition, an electricity rate other than the DP rate may be applied as the electricity rate for the second electrical equipment. The electricity rate for the second electrical equipment can be any rate different from the electricity rate for the first electrical equipment, for example, it may be a different fixed electricity rate that differs from the fixed electricity rate for the first electrical equipment.

[0040] Current sensors 61 and 62 measure the current flowing at a predetermined location. Current sensors 61 and 62 include, for example, a current transformer and an ammeter connected to the current transformer. Current sensors 61 and 62 are placed in the power distribution line between the distribution board and the power meter 200 of the house 100.

[0041] The current sensor 61 is installed between the power meters 41 and 200 on the dedicated wiring of the house 100 and measures the current (reverse current) flowing through the wiring. In other words, the current sensor 61 measures the current output from the house 100 to the power system 300.

[0042] The current sensor 62 is installed between the power meters 42 and 200 on the dedicated wiring of the house 100 and measures the current (forward current) flowing through the wiring. In other words, the current sensor 62 measures the current (forward current) flowing to the charger 52.

[0043] The power management system 1 may also be equipped with a single current sensor (for example, the current sensor 63 shown in Figure 5, described later) at the power receiving point instead of current sensors 61 and 62. This single current sensor measures the current flowing through the power receiving point. In other words, this single current sensor measures the current flowing from the power receiving point to the house 100 side (downstream) and the current flowing from the house 100 to the power receiving point side (upstream). By equipping the power management system 1 with such a current sensor, the house 100 can meet the conditions for using the FIT system (Feed-In Tariff).

[0044] Furthermore, the current values ​​measured by current sensors 61 and 62 can be substituted by the current values ​​measured by at least one of the power meters 41, 42, and 200. For example, the current value measured by current sensor 61 can be substituted by the current value of reverse-flowing power measured by power meter 41 or 200. Also, for example, the current value measured by current sensor 62 can be substituted by the current value of forward-flowing power measured by power meter 42. Therefore, for example, if the current value measured by at least one of the power meters 41, 42, and 200 is output to the management device 70, at least one (for example, both) of the current sensors 61 and 62 may not be provided.

[0045] The management device 70 manages the power supply of the first and second electrical devices. For example, the management device 70 performs various processes to supply part or all of the power generated by the solar cell 10 to the charger 52. The management device 70 may be installed inside the house 100 or remotely from the house 100. The management device 70 may be installed, for example, in a control terminal for controlling the home appliances 51 installed inside the house 100, or it may be implemented by a server device that is communicatively connected to each meter and each sensor.

[0046] Figure 2 is a block diagram showing the functional configuration of the management device 70 according to this embodiment.

[0047] As shown in Figure 2, the management device 70 comprises an acquisition unit 71, a calculation unit 72, and an output unit 73. Each component of the management device 70 is realized, for example, by a microcomputer or processor (hardware) constituting the management device 70 executing a computer program (software) stored in a storage unit (not shown).

[0048] The acquisition unit 71 acquires power values ​​measured from various measuring instruments. The acquisition unit 71 acquires a power value W1_s (an example of a first power value) from the power meter 41, which measures the power flowing in reverse from the solar cell 10 to the power grid 300. The acquisition unit 71 functions as a first acquisition unit. The acquisition unit 71 also acquires a power value W2_b (an example of a second power value) from the power meter 42, which measures the power flowing in forward from the power grid 300. The acquisition unit 71 functions as a second acquisition unit. The acquisition unit 71 also acquires a power value W1_b from the power meter 41, which measures the power flowing in forward from the power grid 300 to the home appliance 51. The units of the power values ​​W1_s, W1_b, and W2_b are, for example, "W (watts)".

[0049] The acquisition unit 71 may include a communication module (communication circuit) for communicating with the power meters 41 and 42. The acquisition unit 71 may communicate via wired communication or wireless communication. Furthermore, there are no particular limitations on the communication standard used for communication. In addition, the acquisition unit 71 is not limited to directly communicating with the power meters 41 and 42, and may acquire the power values ​​measured by the power meters 41 and 42 via other devices. Furthermore, the acquisition unit 71 may be connected to input devices such as buttons, touch panels, or sound collection devices (e.g., microphones), and may be able to acquire each power value without going through a communication network.

[0050] The calculation unit 72 calculates the amount of electricity purchased from the power grid 300 and the amount of electricity sold to the power grid 300 at the house 100 based on the acquired power values ​​W1_s and W2_b. Specifically, the calculation unit 72 calculates the amount of electricity purchased and the amount of electricity sold based on the smaller of the power values ​​W1_s and W2_b. For example, the calculation unit 72 calculates the smaller power value as the power Y (first power) transferred from the solar cell 10 to the charger 52, calculates the purchased power and the sold power by subtracting the power Y from the power values ​​W1_s and W2_b, and calculates the amount of electricity purchased and the amount of electricity sold by integrating the calculated purchased power and the sold power.

[0051] If the power value W1_s is smaller than the power value W2_b, for example, all of the power value W1_s will be used as the power Y (= power value W1_s) supplied to the charger 52, and the deficit will be purchased from the power grid 300. In this case, the power sold will be zero. Also, if the power value W2_b is smaller than the power value W1_s, for example, the amount of power value W2_b from the power value W1_s will be used as the power Y (= power value W2_b) supplied to the charger 52, and the surplus will be sold to the power grid 300 or supplied to the home appliance 51. In this case, the power purchased for the charger 52 will be zero.

[0052] The purchased electricity and sold electricity can be expressed by the following formula:

[0053] Purchased power for charger 52 = W2_b - Y[W] (Equation 1) Electricity sold = W1_s - Y[W] (Equation 2) Interchangeable power Y=Min(W1_s, W2_b)[W] (Formula 3) Purchased power for home appliance 51 = W1_b [W] (Equation 4)

[0054] The power calculated using Equation 1 is the power to which the DP unit price applies, and the power calculated using Equation 4 is the power to which the fixed power unit price applies. The purchased power for home appliances 51 refers to the power to which the conventional fixed power unit price is charged. The purchased power for chargers 52 refers to the power to which the DP unit price is charged.

[0055] Furthermore, in the power management system 1, the power supply path is controlled so that the bridging power Y calculated by the calculation unit 72 is actually supplied to the charger 52.

[0056] The above-mentioned shared power Y corresponds to the portion of the PV power of the solar cell 10 that is consumed by the charger 52. The calculation unit 72 calculates the purchased power for the charger 52 using the above-mentioned equations 1 and 3, thereby separating the power measured by the power meter 42 into power purchased from the power grid 300 and power consumed by the charger 52.

[0057] The calculation unit 72 only needs to calculate at least one of the amount of electricity purchased and the amount of electricity sold.

[0058] The output unit 73 outputs the amount of purchased electricity and the amount of sold electricity calculated by the calculation unit 72 to an external device (for example, a higher-level system). The output unit 73 outputs the amount of purchased electricity and the amount of sold electricity to a server device managed by a retail electricity provider, for example. The output unit 73 outputs the amount of purchased electricity calculated using formula 1 and accumulated over a predetermined period as the amount of electricity subject to DP unit price billing, and outputs the amount of purchased electricity calculated using formula 4 and accumulated over a predetermined period as the amount of electricity subject to conventional fixed electricity unit price billing. Thus, in the example in Figure 1, the output unit 73 outputs the amount of purchased electricity subject to DP unit price billing, which is not the amount of electricity itself that is the sum of the electricity measured by the electricity meter 42, but rather the amount of electricity obtained by subtracting the supplied electricity Y from the electricity measured by the electricity meter 42 and accumulating that amount of electricity.

[0059] The output unit 73 may output the amount of electricity purchased and the amount of electricity sold via wireless communication, for example, but it may also output the amount of electricity purchased and the amount of electricity sold via wired communication. Alternatively, the output unit 73 may output the amount of electricity purchased and the amount of electricity sold to the customer's terminal device.

[0060] Referring again to Figure 1, the power meter 200 is a power sensor connected between power meters 41 and 42 and the power grid 300, and measures at least one of the third power value flowing in the forward direction from the power grid 300 (power value W_b shown in Figure 5 later) and the fourth power value flowing in the reverse direction from the solar cell 10 to the power grid 300 (power value W_s shown in Figure 5 later). The power meter 200 measures, for example, the power supplied from one party, a retail electricity provider and a point of power reception, to the other (i.e., the power supplied (purchased) from the power grid 300 to the house 100, and the power sold from the house 100 to the power grid 300). Thus, the power meter 200 functions as at least one of a power receiving power meter that measures the power supplied from the power grid 300, and a power selling power meter that measures the power sold in the reverse direction from the house 100 to the retail electricity provider at a predetermined price using the FIT system. The power meter 200 is an example of a third measuring instrument.

[0061] The point where the power meter 200 is installed may be the point of responsibility division between the area belonging to the residence 100 and the area belonging to the power system 300, or it may be the location where the service entrance switchboard (low voltage) or power receiving equipment (high voltage) is located.

[0062] Retail electricity providers are businesses that buy and sell electricity based on the readings of electricity meters 200. These retail electricity providers sell electricity to general households, buildings, factories, etc. The readings from electricity meters 200 are transmitted to the retail electricity providers.

[0063] Power grid 300 is a grid operated by a retail electricity provider and has its own grid power source.

[0064] [2. Operation of the Power Management System] Figure 3 is a flowchart showing the operation (power management method) of the management device 70 according to this embodiment. Steps S11 and S12 are performed before power is exchanged.

[0065] As shown in Figure 3, the acquisition unit 71 of the management device 70 acquires a first power value from the power meter 41, which is the power flowing in reverse from the distributed power source to the power grid 300 (S11). In step S11, the acquisition unit 71 acquires the power value W1_s.

[0066] Next, the acquisition unit 71 acquires a second power value, which is the power flowing in the direction of current, from the power meter 42 (S12). In step S12, the acquisition unit 71 acquires the power value W2_b.

[0067] The timing and order of acquiring the first and second power values ​​are not particularly limited. The first and second power values ​​may be acquired simultaneously.

[0068] Next, the calculation unit 72 calculates the amount of electricity purchased from the power system 300 and the amount of electricity sold to the power system 300 based on the smaller of the first power value and the second power value (S13). The calculation unit 72 calculates the amount of electricity purchased and the amount of electricity sold using the above equations 1 to 3.

[0069] Next, the output unit 73 outputs the amount of electricity purchased and the amount of electricity sold, calculated by the calculation unit 72, to an external device (S14). This makes it possible to calculate the purchase price and the sale price based on the accurate amount of electricity purchased and the amount of electricity sold.

[0070] [3. Examples of applications of power management systems] The following describes various application examples of the power management system 1 according to this embodiment, with reference to Figures 4 to 10. First, the first application example will be described with reference to Figure 4. Figure 4 is a diagram showing the first application example of the power management system 1 according to this embodiment. In Figure 4, an example is described in which power meters 441 and 442 are both smart meters. Power meter 441 corresponds to power meter 41 shown in Figure 1 and is an example of a first measuring instrument. Power meter 442 corresponds to power meter 42 shown in Figure 1 and is an example of a second measuring instrument. A current sensor 61 is located downstream of power meter 441, and a current sensor 62 is located downstream of power meter 442. Power meters 441 and 442 are built into a housing 400, for example.

[0071] For convenience, the management device 70, the house 100, etc., are omitted from the illustrations in Figure 4 and subsequent figures.

[0072] As shown in Figure 4, a smart meter, power meter 441, is placed between the power grid 300 and the home appliance 51, and a smart meter, power meter 442, is placed between the power grid 300 and the charger 52. Power meters 441 and 442 are located at points such as the responsibility division point between the area belonging to the house 100 and the area belonging to the power grid 300, and in this application example, power is exchanged upstream of power meters 441 and 442.

[0073] In this case, the calculation unit 72 calculates the smaller of the first power value (power value W1_s), which is the reverse power obtained from the power meter 441, and the second power value (power value W2_b), which is the forward power obtained from the power meter 442, as the power Y to be supplied from the distributed power source to the second electrical equipment. Then, the calculation unit 72 calculates the amount of electricity purchased and the amount of electricity sold by subtracting the power Y from the first power value and the second power value. Note that the exchange of electricity may be carried out via a transmission and distribution network maintained and operated by a general transmission and distribution company.

[0074] Next, a second application example will be described with reference to Figures 5 and 6. Figure 5 is a diagram showing a second application example of the power management system 1 according to this embodiment. In Figure 5, an example is described in which the power meters 41 and 42 are conventional power meters and not smart meters, and the power meter 200 is placed at the responsibility division point. The power meter 200 may be a smart meter or a conventional power meter. Also, the power meters 41 and 42 may be measuring instruments that do not undergo verification under the Measurement Law (specified measuring instruments) under certain conditions. Furthermore, the acquisition unit 71 is connected to the power meter 200 in a communicative manner and acquires measured values ​​from the power meter 200.

[0075] As shown in Figure 5, power meters 41 and 42 are located in the distribution board 80a to which the home appliance 51 and charger 52 are connected, and power meter 200 is connected between the distribution board 80a and the power grid 300. In this application example, power meter 200 measures at least the third power value (i.e., the power value W_b which is the purchased power (current power) that the house 100 has purchased from the power grid 300). Power meters 41 and 42 may also be capable of measuring power every few milliseconds. A current sensor 63 is also located between power meter 200 and the distribution board 80a.

[0076] In such cases, the calculation unit 72 calculates each power using equations 5 and 6 below.

[0077] Purchased power for home appliance 51 (first purchased power) = W_b - (W2_b - Y) [W] (Equation 5) Purchased power for charger 52 (second purchased power) = W2_b - Y[W] (Equation 6)

[0078] The formula for calculating the power exchange Y is the same as in Equation 3, and therefore is omitted from this description.

[0079] Furthermore, (W2_b-Y) shown in Equation 6 represents the second power value, which is the power supplied from the power system 300 to the charger 52 (power purchased from the power system 300). The exchange of the power Y here can be carried out downstream of the power meter 200 located at the responsibility demarcation point. For example, it can be carried out via the wiring within the house 100. The power Y is the in-house power that can be exchanged within the house 100. In other words, the power management system 1 in this application example allows for power exchange without using the transmission and distribution network maintained and operated by a general power transmission and distribution company.

[0080] The calculation unit 72 calculates the first purchased power by subtracting the second power value from the third power value (power value W_b), as shown in Equation 5.

[0081] Furthermore, the calculation unit 72 may calculate the total load power (power consumption) of the entire house 100 using the following formula 7, and the load power (power consumption) of equipment other than the charger 52 in the house 100 using the following formula 8. Equipment other than the charger 52 means all equipment installed in the house 100 to which a fixed power unit price applies (i.e., all equipment to which the DP price does not apply).

[0082] Total power consumption for the entire house 100 = W_b + PV power - W_s (Equation 7) The total power consumption of all devices in house 100 except for charger 52 = W_b + PV power - W_s - W2_b (Equation 8)

[0083] Furthermore, the calculation unit 72 may switch the calculation method for the shared power Y according to the electricity unit price for the second purchased power. The case in which the calculation method for shared power Y is switched will be explained with reference to Figure 6. Figure 6 is a diagram for explaining the calculation method for shared power Y in a second application example of the power management system 1 according to this embodiment. Figure 6(a) is a diagram for explaining the calculation method for shared power Y when the dynamic pricing price is high, and Figure 6(b) is a diagram for explaining the calculation method for shared power Y when the dynamic pricing price is low. Note that in Figure 6, the connection relationships within the distribution board 80a are changed from those in Figure 5. For example, the home appliance 51 is connected so that it can receive power from the power system 300 without going through the power meter 41.

[0084] A surge in dynamic pricing prices occurs, for example, when the DP unit price is equal to or greater than a fixed electricity unit price (an example of a predetermined unit price), and a decline in dynamic pricing prices occurs, for example, when the DP unit price is less than a fixed electricity unit price (an example of a predetermined unit price). The predetermined unit price is not limited to a fixed electricity unit price, but may be any other unit price set in advance. The predetermined unit prices used to determine surges and declines may be the same unit price or may be different unit prices. The predetermined unit prices are stored, for example, in the memory of the management device 70. The acquisition unit 71 may also acquire the DP unit price from a server device or the like that manages the DP unit price.

[0085] The calculation unit 72 determines whether the DP unit price is equal to or greater than a predetermined unit price, and adjusts the calculation method in step S13 shown in Figure 3 according to the determination result.

[0086] As shown in Figure 6(a), when the DP unit price is high, the surplus power Y1 is preferentially supplied to the charger 52. In this case, the PV power generated by the solar cell 10 is not charged to the storage battery 30, but is managed to be supplied as much as possible to the charger 52 to which the DP unit price applies. The calculation unit 72 calculates each power using the following equations 9 to 11.

[0087] Interchangeable power Y1=Min(PV power, W2_b)[W] (Formula 9) Purchased power for charger 52 (second purchased power) = W2_b - Y1 [W] (Equation 10) Purchased power for home appliance 51 (first purchased power) = W_b - (W2_b - Y1) [W] (Equation 11)

[0088] The shared power Y1 is the power from the PV power that is shared with the charger 52, and is an example of the first shared power.

[0089] Thus, if the power unit price (DP unit price) for the second purchased power is equal to or greater than a predetermined unit price, the calculation unit 72 calculates the smaller of the PV power and the power value W2_b as the circulating power Y1.

[0090] Furthermore, as shown in Figure 6(b), when the DP unit price falls, the shared power Y2 (an example of second shared power) is preferentially provided to the home appliances 51. In this case, the PV power generated by the solar cell 10 is managed so that as much as possible is provided to the home appliances 51 to which a fixed electricity unit price applies. The calculation unit 72 calculates each shared power using the following equations 12 and 13.

[0091] Interchangeable power Y2=Min(PV power, W1_b)[W] (Formula 12) Interchangeable power Y1=PV power-W_s-Y2[W] (Formula 13)

[0092] Furthermore, the purchased power for charger 52 (second purchased power) and the purchased power for home appliance 51 (first purchased power) can be calculated by substituting the circulating power Y1 in equation 13 into equations 10 and 11. In addition, the power value W1_b can be obtained from the measured values ​​of power meters 41, 42, and 200.

[0093] Furthermore, when the DP unit price falls, power may not be supplied to the charger 52. In other words, the supplied power Y1 may be zero. For example, (PV power - Y2) shown in Equation 13 and the power value W_s may be the same value.

[0094] Thus, if the electricity unit price (DP unit price) for the second purchased electricity is less than a predetermined unit price, the calculation unit 72 calculates a power value lower than the power Y1 provided by Equation 9 (the power value calculated by Equation 13) as the power Y1 provided. If the electricity unit price for the second purchased electricity is less than a predetermined unit price, the calculation unit 72 may set the power Y1 provided to 0, or calculate the power Y1 provided based on the power Y2 provided from the solar cell 10 to the home appliance 51.

[0095] Next, a third application example will be explained with reference to Figure 7. Figure 7 is a diagram showing a third application example of the power management system 1 according to this embodiment. In Figure 7, an example in which a specific metering panel 90 is provided will be explained.

[0096] As shown in Figure 7, the power management system 1 further includes a specific metering panel 90 that incorporates specific measuring instruments, namely power meters 41 and 42. The specific metering panel 90 is connected between the distribution board 80 to which the home appliances 51 are connected and the power meter 200. It can also be said that the power meter 200 is connected between the power system 300 and the specific metering panel 90. Furthermore, the specific metering panel 90 is connected to the power conversion system 20 (i.e., the solar cell 10) and the charger 52. Note that the distribution board 80 does not have power meters 41 and 42 installed.

[0097] The electricity purchased from the power meter 200 (electricity purchased from the power grid 300) can be supplied to the home appliance 51 via the distribution board 80, and to the charger 52 via the power meter 42. In addition, PV power can be supplied to the home appliance 51 and the charger 52 via the power meter 41, and can also be sold back to the grid.

[0098] For example, the specific metering panel 90 is a separate hardware enclosure distinct from the distribution panel 80, and is configured to allow switching between selling the PV power from the solar panels 10 via the power meter 200, supplying it to the charger 52 via the power meter 42, or supplying it to home appliances 51 via the distribution panel 80. Furthermore, the specific metering panel 90 is a 2-input, 2-output specific metering panel.

[0099] In this way, since the location of the PV power supplied from the solar cell 10 is determined by the specific metering panel 90 (i.e., hardware), the reliability of the measurements taken by the power meters 41 and 42 can be improved.

[0100] Furthermore, when a specific metering panel 90 is installed, the calculation method for the circulating power Y1 and Y2 may be switched depending on the level of the DP unit price. In this case, the calculation method is dynamically switched by the control device 70.

[0101] Next, a fourth application example will be described with reference to Figure 8. Figure 8 is a diagram showing a fourth application example of the power management system 1 according to this embodiment. In Figure 8, an example in which a switch unit 95 is provided in addition to the specific metering panel 90a will be described.

[0102] As shown in Figure 8, the power management system 1 includes a specific metering panel 90a that incorporates specific measuring instruments, power meters 41 and 42, as well as a switch unit 95 that switches whether the power conversion system 20 (i.e., solar cell 10) is connected to home appliances 51 via the power meter 41 and distribution board 80, or to the power meter 42 and charger 52. The switch unit 95 is a physical switch having one movable contact and two fixed contacts (fixed contacts A and B), but it may also be a touch switch, for example. Fixed contact A is connected to home appliances 51 via the power meter 41 and distribution board 80, and fixed contact B is connected to the power meter 42 and charger 52.

[0103] The switch unit 95 is controlled to switch the connection destination depending on whether the DP unit price is above a predetermined unit price. If the DP unit price is above a first predetermined unit price, the switch unit 95 connects the movable contact to the fixed contact B, and if the DP unit price is below a second predetermined unit price (for example, if the DP unit price is below the first predetermined unit price), the switch unit 95 connects the movable contact to the fixed contact A. This makes it possible to reduce the amount of electricity purchased from the power grid 300.

[0104] In this case, the switch unit 95 is dynamically switched according to the DP unit price, but the calculation method for the circulating power Y is fixed (for example, equation 6). When the movable contact and fixed contact A are connected, the power meter 41 measures the surplus power obtained by subtracting the power supplied to the home appliance 51 from the PV power as the power value W1_s. When the movable contact and fixed contact B are connected, the power meter 42 measures the surplus power obtained by subtracting the power supplied to the charger 52 from the PV power as the power value W1_s.

[0105] Furthermore, the power Y exchanged can be calculated using Equation 3, with the power value W1_s of the reverse power measured by power meter 41 and the power value W2_b of the forward power measured by power meter 42.

[0106] The control of the switch unit 95 and the determination of whether the DP unit price is equal to or greater than a predetermined unit price may be performed by the management device 70 or by other devices.

[0107] Next, a fifth application example will be explained with reference to Figure 9. Figure 9 is a diagram showing a fifth application example of the power management system 1 according to this embodiment. In Figure 9, an example of power exchange upstream of the smart meters, power meters 200, 201 and 202, will be explained. In Figure 9, an air conditioner 51a, which is an example of a home appliance 51, and an electric vehicle V10 connected to a charger 52 are shown.

[0108] As shown in Figure 9, the power management system 1 includes power meters 200, 201, and 202. Power meters 200, 201, and 202 are smart meters. In addition, one or two of the power meters 200, 201, and 202 may be located at a location remote from the house 100. For example, power meter 200 may be located in the house 100, while power meters 201 and 202 may be located at different locations remote from the house 100. Power meter 201 is an example of a first measuring instrument, and power meter 202 is an example of a second measuring instrument.

[0109] In such a configuration, when electricity is exchanged, the exchange will take place upstream of electricity meters 200, 201, and 202. The exchange of electricity may, for example, be carried out via a transmission and distribution network maintained and operated by a general power transmission and distribution company.

[0110] The calculation unit 72 calculates the amount of power to be supplied when PV power is supplied to at least one of the home appliance 51 and the charger 52. The management device 70 may also sell all the electricity without supplying any PV power. The following describes the case in which power is supplied to the home appliance 51 and the charger 52. It is also assumed that the DP unit price has fallen. In this case, the calculation unit 72 determines that power should be supplied to the home appliance 51 as a priority.

[0111] The calculation unit 72 first calculates the power Y1 supplied to the home appliance 51, and if the PV power is greater than W1_b, it further calculates the power Y2 supplied to the charger 52. The calculation unit 72 calculates the power Y1 and Y2 based on the following equations 14 and 15.

[0112] Interchangeable power Y1=Min(PV power, W1_b)[W] (Formula 14) Interchangeable power Y2=Min(PV power-Y1, W2_b)[W] (Formula 15)

[0113] Furthermore, the calculation unit 72 calculates the electricity sold and the electricity purchased (charged electricity) in this case based on the following equations 16 to 18.

[0114] Electricity sold = PV power - Y1 - Y2 [W] (Equation 16) Purchased power for home appliance 51 = W1_b - Y1 [W] (Equation 17) Purchased power for charger 52 = W2_b - Y2[W] (Equation 18)

[0115] This makes it possible to calculate the amount of purchased electricity when electricity is exchanged upstream of the power meters 41 and 42, for example, when self-transmission occurs between points in a 3-point supply contract.

[0116] Next, the sixth application example will be explained with reference to Figure 10. Figure 10 is a diagram showing the sixth application example of the power management system 1 according to this embodiment. Figure 10 explains an example in which the DP unit price differs depending on the equipment within a house 100.

[0117] As shown in Figure 10, the power management system 1 includes electrical equipment consisting of a home appliance 51, a charger 52, and an electric water heater 53. The home appliance 51 is an appliance to which a fixed electricity unit price applies. The charger 52 and the electric water heater 53 are appliances to which a DP unit price applies, but their DP unit prices are different. The DP unit price for the charger 52 is called the first DP unit price, and the DP unit price applied to the electric water heater 53 is called the second DP unit price. Since the electricity unit prices for the first and second DP units fluctuate depending on the time of day, there are times when the first DP unit price is higher and times when the second DP unit price is higher. In this application example, the recipients of PV power (priority order of power sharing) change dynamically depending on the relative levels of the first and second DP unit prices. Below, we will mainly explain the case where the first DP unit price is higher than the second DP unit price (i.e., when the charger 52 is prioritized over the electric water heater 53).

[0118] Furthermore, the power management system 1 includes a power meter 43 (labeled "M3" in Figure 10) in addition to power meters 41 and 42. The power meter 43 measures the power (purchased power) flowing from the power grid 300 to the electric water heater 53. The acquisition unit 71 of the management device 70 is configured to acquire the power value W3_b measured by the power meter 43.

[0119] In this case, the calculation unit 72 first calculates the power Y1 to be supplied to the charger 52, which has a higher priority for supplying power. The calculation unit 72 calculates the power Y1 using, for example, equation 3. Next, if the power value W2_b is smaller than the power value W1_s, the calculation unit 72 further calculates the power Y2 to be supplied to the electric water heater 53 using the following equation 19.

[0120] Interchangeable power Y2==Min((W1_s-Y1), W3_b)[W] (Formula 19)

[0121] Furthermore, if the second DP unit price is higher than the first DP unit price, the calculation unit 72 calculates the shared power Y2 and Y1 using the following equations 20 and 21.

[0122] Interchangeable power Y2==Min(W1_s, W3_b)[W] (Formula 20) Interchangeable power Y1==Min((W1_s-Y2), W2_b)[W] (Formula 21)

[0123] This makes it possible to calculate the purchased power (power minus the power supplied) for each piece of equipment, even if there are pieces of equipment with different DP unit prices in a single house (house 100).

[0124] Furthermore, if the unit price for the first DP and the unit price for the second DP are the same, PV power may be preferentially supplied to a predetermined device among the charger 52 and the electric water heater 53.

[0125] The exchange of electricity may be carried out using the wiring within the house 100, or it may be carried out via a power transmission and distribution network maintained and operated by a general power transmission and distribution company.

[0126] (Modified example of the embodiment) In the following, the power management system 1 according to this modified example will be described with reference to Figures 11 to 13. Note that the following description will focus on the differences from the embodiment, and explanations of content that is the same as or similar to the embodiment will be omitted or simplified.

[0127] Figure 11 shows the configuration of the power management system 1 according to this modified example. In this modified example, we will explain the case where the solar cells 10 are installed in a house 100a by a PPA (Power Purchase Agreement) operator. The PPA operator sells the generated electricity (PV power) produced by the solar cells 10 to the customer in the house 100a. In addition, if the storage battery 30 is installed in the house 100a by the PPA operator, when the discharged power from the storage battery 30 is supplied to the home appliance 51, electricity sales from the PPA operator to the customer in the house 100a occur. Note that a retail electricity business may also conduct a PPA business.

[0128] As shown in Figure 11, the power management system 1 includes a power meter 44 (labeled "M4" in Figure 11) in addition to the power management system 1 shown in Figure 1.

[0129] The power meter 44 is connected between the power conversion system 20 and the home appliance 51 and measures the power value W3_s supplied to the home appliance 51 from the PPA operator and the power value W3_b of the electricity purchased from the retail electricity provider. The power meter 44 can also be said to measure the power supplied from one of the solar cells 10 (an example of a distributed power source) and the home appliance 51 (an example of a first electrical appliance) to the other. The power meter 44 may be a conventional power meter or a smart meter. The power meter 44 is an example of a fourth measuring instrument.

[0130] Furthermore, the acquisition unit 71 of the management device 70 functions as a third acquisition unit that acquires power values ​​W3_s and W3_b from the power meter 44.

[0131] The calculation unit 72 calculates the amount of electricity purchased by a residential customer (100a) using the following equations 22 to 25.

[0132] The power purchased from the retail electricity supplier for the home appliance 51 = W1_b - W3_b [W] (Equation 22) Power purchased from the PPA provider for home appliance 51 = W3_s[W] (Equation 23) Power purchased from the retail electricity provider for charger 52 = W2_b - Y[W] (Equation 24) Power purchased from the PPA operator for charger 52 = Y [W] (Equation 25)

[0133] Furthermore, the calculation unit 72 calculates the electricity sold by the PPA operator to consumers, the electricity purchased by the PPA operator from retail electricity providers, and the electricity sold by the PPA operator to retail electricity providers using the following equations 26 to 29. Equation 29 is an equation for calculating the electricity purchased by the PPA operator from retail electricity providers for the home appliances 51.

[0134] Power sold by the PPA operator for household appliances 51 = W3_s - W1_s [W] (Equation 26) Power sold by the PPA operator to charger 52 = Y [W] (Equation 27) Electricity sold to retail electricity providers = W1_s - Y[W] (Equation 28) Purchased electricity from retail electricity provider = W3_b [W] (Equation 29)

[0135] Next, we will describe examples of applications of the power management system 1 according to this modified example. Below, Figure 12 shows an example in which the power management system 1 according to this modified example is applied to the first application example of each of the embodiments, and Figure 13 shows an example in which the power management system 1 according to this modified example is applied to the second application example. Figures 12 and 13 are diagrams showing each application example of the power management system 1 according to this modified example. Note that the power management system 1 according to this modified example can be applied to any of the application examples of the embodiments.

[0136] As shown in Figure 12, the power management system 1 according to this modified example includes a power meter 44 in addition to the power management system 1 shown in Figure 4 of the embodiment.

[0137] The power meter 44 is connected between the power meter 441 and the distribution board 80 and the power conversion system 20.

[0138] In such a power management system 1, the calculation unit 72 can calculate various powers by using the above-mentioned equations 22 to 29.

[0139] Furthermore, as shown in Figure 13, the power management system 1 according to this modified example has a configuration in which the home appliances 51 are connected via a branch circuit 81, similar to the power management system 1 shown in Figure 5 of the embodiment. In this case, there is no need to provide a power meter 44.

[0140] In this case, the calculation unit 72 calculates the amount of electricity purchased by the customer of the house 100a using the following equations 30 and 31.

[0141] The power purchased from the retail electricity supplier for the home appliance 51 = W_b - W1_b - W2_b [W] (Equation 30) Power purchased from the PPA provider for home appliance 51 = W1_b - Y - W_s [W] (Equation 31)

[0142] The electricity purchased from retail electricity providers and the electricity purchased from PPA providers for charger 52 can be calculated using equations 24 and 25, and are therefore omitted from this description.

[0143] Furthermore, the calculation unit 72 calculates the electricity sold by the PPA operator to consumers, the electricity purchased by the PPA operator from retail electricity providers, and the electricity sold by the PPA operator to retail electricity providers using the following equations 32 to 34.

[0144] The power sold by the PPA operator for home appliance 51 = W1_b - Y - W_s [W] (Equation 32) Electricity sold to retail electricity providers = W_s[W] (Equation 33) Purchased electricity from retail electricity provider = W1_b [W] (Equation 34)

[0145] The electricity sold by the PPA operator to charger 52 can be calculated using formula 27, and is therefore omitted from this description.

[0146] In such a power management system 1, the calculation unit 72 can calculate various powers by using the above-mentioned equations 24, 25, 27, and 30 to 34.

[0147] (Effects, etc.) The inventions derived from the disclosures in this specification, and the effects obtained by said inventions, are described below.

[0148] (Invention 1) A power management system 1 manages the power of a first electrical device (e.g., a home appliance 51) and a second electrical device (e.g., a charger 52), wherein different unit prices are set for the first purchased power supplied to the first electrical device and the second purchased power supplied to the second electrical device, and the power management system 1 measures a first power value (e.g., power) obtained by measuring the power flowing back from the distributed power source to the power grid 300 from a first measuring instrument (e.g., a power meter 41) to which the distributed power source (e.g., a solar cell 10) and the first electrical device are electrically connected. The power management system 1 comprises a first acquisition unit (e.g., acquisition unit 71) that acquires a value W1_s or PV power; a second acquisition unit (e.g., acquisition unit 71) that acquires a second power value (e.g., power value W2_b) measured from a second measuring instrument (e.g., power meter 42) electrically connected to a second electrical device, which measures the power flowing in from the power system 300; and a calculation unit 72 that calculates at least one of the amount of electricity purchased from the power system 300 and the amount of electricity sold to the power system 300 based on the smaller of the first power value and the second power value.

[0149] As a result, in the power management system 1, when power is supplied to the second electrical equipment and sold to the power grid 300 using the smaller power value, which is the power value based on the reverse-flow power, the smaller power value is used, making it possible to reduce the influence of self-consumption by the second electrical equipment on at least one of the measured purchased power amount and sold power amount. Therefore, the power management system 1 can accurately calculate at least one of the purchased power amount and sold power amount when there are distributed power sources within the facility (for example, within the house 100).

[0150] (Invention 2) The calculation unit 72 calculates the smaller power value as the first power supplied from the distributed power source to the second electrical equipment, and calculates at least one of the amount of electricity purchased and the amount of electricity sold by subtracting the first power supplied from the first power value and the second power value, which is the power management system 1 of Invention 1.

[0151] As a result, the first shared power is subtracted from the second power value, allowing the second power value to be separated into the first shared power, which is the amount of electricity consumed by the second electrical equipment, and the amount of electricity purchased from the power grid 300. Therefore, it is possible to accurately calculate at least one of the purchased amount of electricity and the amount of electricity sold.

[0152] (Invention 3) The calculation unit 72 is a power management system 1 of Invention 2 that switches the calculation method for the first shared power according to the unit price of electricity for the second purchased power.

[0153] This makes it possible to reduce the purchase price from the power grid 300, thereby reducing the financial burden on consumers with a power management system 1 when purchasing electricity.

[0154] (Invention 4) The calculation unit 72 is a power management system 1 of Invention 3, which calculates the smaller power value as the first supplied power when the power unit price for the second purchased power is equal to or equal to a predetermined unit price, and calculates a power value lower than the smaller power value as the first supplied power when the power unit price for the second purchased power is less than the predetermined unit price.

[0155] As a result, when the electricity price is high, the amount of electricity exchanged in the first unit increases, and when the electricity price is low, the amount of electricity exchanged in the first unit decreases, thus effectively reducing the financial burden on electricity purchases for consumers with the electricity management system 1.

[0156] (Invention 5) The calculation unit 72 is a power management system 1 of Invention 4, which, when the unit price of electricity for the second purchased power is less than a predetermined unit price, sets the first supplied power to 0, or calculates the first supplied power based on the second supplied power supplied from the distributed power source to the first electrical equipment.

[0157] As a result, if the electricity price for the second purchased power supply is below a predetermined price, power will be supplied to the first electrical equipment first, thus reducing the amount of electricity purchased for the first electrical equipment. Therefore, even if the electricity price for the second purchased power supply is low, the financial burden on the consumer regarding electricity purchases can be reduced.

[0158] (Invention 6) The power management system 1 of any invention 1 to 5 further comprises a first measuring instrument and a second measuring instrument, the first measuring instrument and the second measuring instrument being smart meters.

[0159] This makes it possible to accurately calculate the amount of electricity purchased and sold when the first and second measuring instruments are smart meters.

[0160] (Invention 7) The power management system 1 according to any of Inventions 2 to 5 further comprises a first measuring instrument and a second measuring instrument, and a third measuring instrument (e.g., a power meter 200) connected between the first and second measuring instruments and the power system 300, which measures at least one of a third power value flowing forward from the power system 300 and a fourth power value flowing backward from the distributed power source to the power system 300, wherein the first and second measuring instruments are provided in a distribution board 80a to which the first and second electrical equipment are connected, and the third measuring instrument is connected between the distribution board 80a and the power system 300.

[0161] This makes it possible to accurately calculate the amount of electricity purchased and the amount of electricity sold when the first and second measuring instruments are installed in the distribution board 80a.

[0162] (Invention 8) The power management system 1 of Invention 7 is a power management system 1 in which the third measuring instrument measures at least a third power value, and the calculation unit 72 calculates the first purchased power by subtracting the second power value from the third power value.

[0163] This allows the calculation unit 72 to easily calculate the first purchased power.

[0164] (Invention 9) The power management system 1 according to any one of Inventions 1 to 8 further comprises a first measuring instrument and a second measuring instrument, a third measuring instrument connected between the first and second measuring instruments and a power system 300 for measuring a third power value flowing in from the power system 300, and a specific measuring panel 90 connected between the third measuring instrument and a distribution board 80 to which the first electrical equipment is connected, the specific measuring panel 90 to which the distributed power supply and the second electrical equipment are connected, the first and second measuring instruments are provided on the specific measuring panel 90, and the third measuring instrument is connected between the specific measuring panel 90 and the power system 300.

[0165] This makes it clear that power is supplied only to equipment connected to the specific metering panel 90, thereby reducing uncertainty in the calculation of electricity consumption.

[0166] (Invention 10) The power management system 1 of Invention 9 further includes a switch unit 95 that switches whether the distributed power supply is connected to the first measuring instrument and first electrical equipment or to the second measuring instrument and second electrical equipment.

[0167] This allows for switching connections using a physical switch, further reducing the uncertainty in calculating power consumption.

[0168] (Invention 11) The switch unit 95 is a power management system 1 of Invention 10, which connects the distributed power source to the first measuring instrument and the first electrical equipment when the electricity unit price for the second purchased power is above a predetermined unit price, and connects the distributed power source to the second measuring instrument and the second electrical equipment when the electricity unit price for the second purchased power is below a predetermined unit price.

[0169] This makes it possible to reduce the financial burden on consumers with a power management system 1 to purchase electricity by using the switch unit 95.

[0170] (Invention 12) The power management system 1 according to any of Inventions 1 to 11 is such that the electricity unit price for the first purchased electricity is a predetermined fixed electricity unit price, and the electricity unit price for the second purchased electricity is an electricity unit price determined by dynamic pricing.

[0171] This makes it possible to accurately calculate the amount of electricity purchased and sold, even when the different price units are fixed electricity rates and electricity rates based on dynamic pricing.

[0172] (Invention 13) The first electrical equipment includes a home appliance 51, and the second electrical equipment includes at least one of a charger 52 and an electric water heater 53, and is a power management system 1 according to any of inventions 1 to 12.

[0173] This makes it possible to accurately calculate the amount of electricity purchased by the charger 52 and the electric water heater 53 in a power management system 1 that includes a home appliance 51 and at least one of the charger 52 and the electric water heater 53.

[0174] (Invention 14) The power management system 1 according to any of Inventions 1 to 13 further comprises a third acquisition unit (e.g., acquisition unit 71) that acquires a measured fourth power value from a fourth measuring instrument (e.g., power meter 44) that measures the power supplied from one of a distributed power source and a first electrical device to the other, and a calculation unit 72 further calculates at least one of the amount of electricity purchased and the amount of electricity sold based on the fourth power value.

[0175] As a result, the fourth power value is used, making it possible to accurately calculate at least one of the purchased electricity amount and the sold electricity amount when a PPA operator has distributed power sources.

[0176] (Invention 15) The calculation unit is a power management system 1 according to any of Inventions 1 to 14, which calculates both the amount of electricity purchased and the amount of electricity sold based on the smaller of the first power value and the second power value.

[0177] As a result, the power management system 1 can accurately calculate both the amount of electricity purchased and the amount of electricity sold.

[0178] (Invention 16) A power management method is performed by a power management system 1 that manages the power of a first electrical device (e.g., a home appliance 51) and a second electrical device (e.g., a charger 52), wherein different unit prices are set for the first purchased power supplied to the first electrical device and the second purchased power supplied to the second electrical device, and the power management method is to obtain a first power value measured from a first measuring instrument (e.g., a power meter 41) electrically connected to a distributed power source (e.g., a solar cell 10) and the first electrical device, which measures the power flowing in reverse from the distributed power source to the power system 300 (S11), obtain a second power value measured from a second measuring instrument (e.g., a power meter 42) electrically connected to the second electrical device, which measures the power flowing in forward from the power system 300 (S12), and calculate at least one of the amount of electricity purchased from the power system 300 and the amount of electricity sold to the power system 300 based on the smaller of the first power value and the second power value (S13).

[0179] (Invention 17) This is a program for causing a computer to execute the power management method of Invention 16.

[0180] This will produce the same effect as the power management system 1 described above.

[0181] These general or specific embodiments may be implemented using a system, method, integrated circuit, computer program, or a non-temporary recording medium such as a computer-readable CD-ROM, or any combination of a system, method, integrated circuit, computer program, or recording medium. The program may be pre-stored on the recording medium or supplied to the recording medium via a wide-area communication network, including the Internet.

[0182] (Other embodiments) Although power management systems and the like according to one or more embodiments have been described above based on embodiments, the present invention is not limited to these embodiments. As long as they do not depart from the spirit of the present invention, various modifications that a person skilled in the art can conceive of may be applied to these embodiments, and forms constructed by combining components from different embodiments may also be included in the present invention.

[0183] For example, in the above embodiments, a solar cell 10 (photovoltaic power generation device) was given as an example of a distributed power source, but the invention is not limited to this, and the distributed power source may be, for example, a wind power generation device, a hydroelectric power generation device, a geothermal power generation device, a biomass power generation device, or a combination thereof.

[0184] Furthermore, while the above embodiments describe an example in which a conventional pricing system is applied to a first electrical appliance, which is a power load directly linked to the power demand associated with daily life, and a dynamic pricing system is applied to a second electrical appliance, which is a power load not directly linked to the power demand associated with daily life, the invention is not limited to this. For example, a dynamic pricing system may be applied to the first electrical appliance, and a normal pricing system may be applied to the second electrical appliance. Also, at least one of the electrical appliances to which the conventional pricing system is applied and the electrical appliances to which the dynamic pricing system is applied may include a mixture of first and second electrical appliances.

[0185] Furthermore, while the above embodiments describe an example in which a dynamic pricing system is applied to the second electrical equipment, the invention is not limited to this, and other pricing systems in which the unit price of electricity fluctuates depending on the circumstances may also be applied.

[0186] Furthermore, in the above embodiments, the contracted power that the house has contracted with the retail electricity provider may be high-voltage power (for example, higher than 60A, 50kW or more but less than 2000kW) or low-voltage power (for example, 60A or less, less than 50kW). Also, either low-voltage power or high-voltage power is supplied to both the first and second electrical appliances in common. In other words, either low-voltage power is supplied to each of the first and second electrical appliances, or high-voltage power is supplied to each of the first and second electrical appliances.

[0187] Furthermore, although the above embodiments described an example in which the management device 70 calculates both the amount of electricity purchased and the amount of electricity sold, it is also possible to calculate only one of the two, for example, the amount of electricity purchased or the amount of electricity sold.

[0188] Furthermore, the order in which each step in the flowchart is executed is illustrative for the purpose of specifically illustrating the present invention, and may be in a different order. Also, some of the above steps may be executed simultaneously (in parallel) with other steps, and some of the above steps may not be executed.

[0189] Furthermore, the division of functional blocks in the block diagram is just one example; multiple functional blocks can be implemented as a single functional block, a single functional block can be divided into multiple parts, or some functions can be moved to other functional blocks. In addition, the functions of multiple functional blocks with similar functions can be processed in parallel or time-sharing by a single piece of hardware or software.

[0190] Furthermore, the management device according to the above embodiments may be implemented as a single device or as a plurality of devices. When the management device is implemented as a plurality of devices, the individual components of the management device may be distributed among the plurality of devices in any manner. When the management device is implemented as a plurality of devices, the method of communication between the plurality of devices is not particularly limited and may be wireless communication or wired communication. In addition, wireless communication and wired communication may be combined between the devices.

[0191] Furthermore, each component described in the above embodiment may be implemented as software, or typically as an integrated circuit (LSI). These may be individually integrated onto a single chip, or some or all of them may be integrated onto a single chip. Here, we refer to them as LSIs, but depending on the degree of integration, they may also be called ICs, system LSIs, super LSIs, or ultra LSIs. Moreover, the method of integrated circuit implementation is not limited to LSIs; it may also be implemented using dedicated circuits (general-purpose circuits that execute dedicated programs) or general-purpose processors. After LSI manufacturing, a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor that allows for the reconfiguration of the connections or settings of circuit cells inside the LSI may be used. Furthermore, if an integrated circuit implementation technology that replaces LSIs emerges due to advances in semiconductor technology or other derived technologies, it is naturally possible to integrate the components using that technology.

[0192] A system LSI is a highly functional LSI manufactured by integrating multiple processing units onto a single chip. Specifically, it is a computer system consisting of a microprocessor, ROM (Read Only Memory), RAM (Random Access Memory), and other components. The ROM stores the computer program. The system LSI achieves its function by operating according to the computer program, with the microprocessor performing its operations.

[0193] Furthermore, one aspect of the present invention may be a computer program that causes a computer to execute each characteristic step included in the power management method shown in Figure 3.

[0194] Furthermore, for example, the program may be a program to be executed by a computer. In another aspect of the present invention, such a program may be recorded on a computer-readable non-temporary recording medium. For example, such a program may be recorded on a recording medium and distributed or made available. For example, by installing the distributed program into a device having another processor and having that processor execute the program, it becomes possible to have that device perform the above-mentioned processes. [Explanation of Symbols]

[0195] 1. Power Management System 10 Solar cells (distributed power supply) 41, 201, 441 Electricity meter (first measuring instrument) 42, 202, 442 Electricity meters (second measuring instrument) 44. Electricity meter (4th measuring instrument) 51. Home appliances (First-class electrical equipment) 51a Air conditioner (First electrical equipment) 52 Charger (Second Electrical Equipment) 53. Electric water heater (Second type of electrical equipment) 71 Acquisition Department (1st Acquisition Department, 2nd Acquisition Department, 3rd Acquisition Department) 72 Calculation Unit 80, 80a distribution board 90, 90a Specific weighing board 95 Switch section 200 Electricity meter (3rd measuring instrument) 300 Power system

Claims

1. A power management system for managing the power supply of the first electrical equipment and the second electrical equipment, Different unit prices are set for the first purchased electricity supplied to the first electrical equipment and the second purchased electricity supplied to the second electrical equipment. The aforementioned power management system is A first acquisition unit acquires a first power value measured from a first measuring instrument electrically connected to the distributed power source and the first electrical equipment, which is the power flowing back from the distributed power source to the power grid. A second acquisition unit acquires a second power value obtained by measuring the power flowing in from the power system from a second measuring instrument electrically connected to the second electrical equipment, The system includes a calculation unit that calculates at least one of the amount of electricity purchased from the power grid and the amount of electricity sold to the power grid, based on the smaller of the first and second power values. Power management system.

2. The calculation unit calculates the smaller of the two power values ​​as the first power supplied from the distributed power source to the second electrical equipment, and calculates at least one of the purchased power amount and the sold power amount by subtracting the first power supplied from the first power value and the second power value. The power management system according to claim 1.

3. The calculation unit switches the calculation method for the first shared power according to the unit price of the second purchased power. The power management system according to claim 2.

4. The calculation unit calculates the smaller power value as the first shared power if the power unit price for the second purchased power is equal to or greater than a predetermined unit price, and calculates a power value lower than the smaller power value as the first shared power if the power unit price for the second purchased power is less than the predetermined unit price. The power management system according to claim 3.

5. The calculation unit determines whether the first shared power is 0 or calculates the first shared power based on the second shared power supplied from the distributed power source to the first electrical equipment if the power unit price for the second purchased power is less than a predetermined unit price. The power management system according to claim 4.

6. The system further comprises the first measuring instrument and the second measuring instrument, The first and second measuring instruments are smart meters. The power management system according to any one of claims 1 to 5.

7. The first measuring instrument and the second measuring instrument, and further comprising a third measuring instrument connected between the first measuring instrument and the second measuring instrument and the power system, which measures at least one of a third power value flowing forward from the power system and a fourth power value flowing backward from the distributed power source to the power system, The first measuring instrument and the second measuring instrument are installed in the distribution board to which the first electrical equipment and the second electrical equipment are connected. The third measuring instrument is connected between the distribution board and the power system. A power management system according to any one of claims 2 to 5.

8. The third measuring instrument measures at least the third power value, The calculation unit calculates the first purchased power by subtracting the second power value from the third power value. The power management system according to claim 7.

9. The first measuring instrument and the second measuring instrument, and a third measuring instrument connected between the first measuring instrument and the second measuring instrument and the power system, which measures a third power value flowing in from the power system, A specific measuring panel connected between the third measuring instrument and the distribution board to which the first electrical equipment is connected, further comprising the distributed power supply and the specific measuring panel to which the second electrical equipment is connected, The first measuring instrument and the second measuring instrument are provided on the specified measuring plate. The third measuring instrument is connected between the specified measuring plate and the power system. The power management system according to any one of claims 1 to 5.

10. The distributed power supply further includes a switch that allows switching between connecting it to the first measuring instrument and the first electrical equipment, or to the second measuring instrument and the second electrical equipment. The power management system according to claim 9.

11. The switch unit connects the distributed power supply to the first measuring instrument and the first electrical equipment when the electricity price for the second purchased power supply is equal to or greater than a predetermined price, and connects the distributed power supply to the second measuring instrument and the second electrical equipment when the electricity price for the second purchased power supply is less than a predetermined price. The power management system according to claim 10.

12. The electricity unit price for the first purchased electricity is a predetermined fixed electricity unit price. The electricity unit price for the second purchased electricity is the electricity unit price determined by dynamic pricing. The power management system according to any one of claims 1 to 5.

13. The aforementioned first electrical equipment includes home appliances, The second electrical device includes at least one of a charger and an electric water heater. The power management system according to any one of claims 1 to 5.

14. The system further includes a third acquisition unit that acquires a measured fourth power value from a fourth measuring instrument that measures the power supplied from one of the distributed power sources and the first electrical equipment to the other, The calculation unit further calculates at least one of the purchased electricity amount and the sold electricity amount based on the fourth power value. The power management system according to any one of claims 1 to 5.

15. The calculation unit calculates both the amount of electricity purchased and the amount of electricity sold based on the smaller of the first and second power values. The power management system according to any one of claims 1 to 5.

16. A power management method implemented by a power management system that manages the power of the first electrical equipment and the second electrical equipment, Different unit prices are set for the first purchased electricity supplied to the first electrical equipment and the second purchased electricity supplied to the second electrical equipment. The aforementioned power management method is, The power management system includes the step of obtaining a first power value, which is obtained by measuring the power flowing back from the distributed power source to the power grid, from a first measuring instrument to which the distributed power source and the first electrical equipment are electrically connected. The power management system includes the step of obtaining a second power value, which is obtained by measuring the power flowing in from the power system, from a second measuring instrument electrically connected to the second electrical equipment, The power management system includes the step of calculating at least one of the amount of electricity purchased from the power grid and the amount of electricity sold to the power grid, based on the smaller of the first power value and the second power value. Power management methods.

17. A program for causing a computer to execute the power management method described in claim 16.

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