Power management system, power management method, and program

Abstract

A power management system (10) comprises a calculation part (36) that calculates an electricity rate for a consumer (90) on the basis of: a first measurement value of first power supplied from a power grid (80) to a first electric device; a measurement value of power that is outputted from a photovoltaic power generation system (21) and that is in a direction opposite to that of the first power; a second measurement value of second power supplied from the power grid (80) to a second electric device; a first power purchasing unit price that is set for the first power; a second power purchasing unit price that is set for the second power; and a virtual power selling unit price that is set for the opposite power. The virtual power selling unit price is the same as the second power purchasing unit price, and the power to be outputted from the photovoltaic power generation system (21) is adjusted so that the opposite power does not flow back to the power grid (80).

Description

Power management system, power management method, and program

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

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

[0003] Website of Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry, [searched on August 21, Reiwa 5], Internet <URL:https: / / www.enecho.meti.go.jp / category / electricity_and_gas / electric / measure / faq / 017.html>

[0004] However, the technique of Non-Patent Document 1 has a problem that when a distributed power source (self-power generation facility) such as a solar cell is present in a facility such as a house, the generated power that is self-consumed is metered as purchased power.

[0005] The present invention provides a power management system and the like that can calculate electricity charges such that self-consumed power is not treated as purchased power.

[0006] A power management system according to one aspect of the present invention is a power management system for managing the power of a first electrical device, a second electrical device, and a distributed power source installed at a consumer, comprising: a first acquisition unit that acquires a first measured value of the first power supplied from the power grid to the first electrical device, measured by a first measuring instrument, and a measured value of the power output from the distributed power source in the opposite direction to the first power; a second acquisition unit that acquires a second measured value of the second power supplied from the power grid to the second electrical device, measured by a second measuring instrument different from the first measuring instrument; and a calculation unit, wherein the power output from the distributed power source is used to manage the power of the consumer and the distributed power source. A sensor for measuring the current between the power system is used to adjust so that the reverse power does not flow back into the power system. A first electricity purchase price is set for the first power, a second electricity purchase price different from the first electricity purchase price is set for the second power, and a virtual electricity sales price, which is the same as the second electricity purchase price, is set for the reverse power to be treated as if the reverse power had been sold. The calculation unit calculates the electricity charge to the customer based on the first measured value, the measured value of the reverse power, the second measured value, the first electricity purchase price, the second electricity purchase price, and the virtual electricity sales price.

[0007] A power management method according to one aspect of the present invention is a power management method performed by a power management system installed at a consumer that manages the power of a first electrical device, a second electrical device, and a distributed power source, and includes a first acquisition step of acquiring a first measured value of a first power supplied from the power system to the first electrical device, measured by a first measuring instrument, and a measured value of power output from the distributed power source in the opposite direction to the first power, a second acquisition step of acquiring a second measured value of a second power supplied from the power system to the second electrical device, measured by a second measuring instrument different from the first measuring instrument, and a calculation step, wherein the power output from the distributed power source is the same as the consumer's power. A sensor is used to measure the current between the customer and the power grid to adjust so that the reverse power does not flow back into the power grid. A first electricity purchase price is set for the first power, a second electricity purchase price different from the first electricity purchase price is set for the second power, and a virtual electricity sales price, which is the same as the second electricity purchase price, is set for the reverse power to be treated as if the reverse power had been sold. In the calculation step, the electricity charge to the customer is calculated based on the first measured value, the measured value of the reverse power, the second measured value, the first electricity purchase price, the second electricity purchase price, and the virtual electricity sales price.

[0008] A program according to one aspect of the present invention is a program that causes the power management system to execute the power management method.

[0009] The power management system of the present invention can calculate electricity charges in such a way that electricity consumed internally is not treated as purchased electricity.

[0010] Figure 1 is a diagram illustrating the problem. Figure 2 is a diagram illustrating an example of the installation of two power meters. Figure 3 is a diagram illustrating the configuration of a power management system according to an embodiment. Figure 4 is a diagram illustrating an example of the unit price of electricity charges indicated by the unit price information. Figure 5 is a flowchart of Example 1 of the calculation operation of electricity charges for a customer. Figure 6 is a diagram illustrating the configuration of a power management system equipped with a third power meter. Figure 7 is a flowchart of Example 2 of the calculation operation of electricity charges for a customer. Figure 8 is a diagram illustrating the adjustment unit price. Figure 9 is a diagram illustrating the configuration of a power management system according to a modified example.

[0011] (Background to the present invention) In recent years, electric vehicles have been spreading. As electric vehicles become more widespread, the concentration of electric vehicle charging during certain times of the day may necessitate power generators to increase their power generation capacity. Figure 1 is a diagram illustrating this issue. Figures 1(a) to (d) each show the daily trend of electricity that power generators need to produce using their own power generation facilities, such as thermal power plants (electricity demand).

[0012] As shown in Figure 1(a), demand generally peaks during the daytime. As electric vehicles become more widespread, many users will charge their electric vehicles as soon as they get home in the evening. This will increase electricity demand in the evening due to electric vehicle charging (corresponding to "EV charging" in Figure 1(a)), causing a demand peak in the evening and widening the gap between the peak and bottom of demand.

[0013] To mitigate the peak demand that occurs in the evening, it is conceivable to introduce a Time Of Use (TOU) pricing system, where the price of electricity purchased is lower during the late night and early morning hours than during the day, instead of a flat rate where the price of electricity purchased is constant at all times of the day. In this case, as shown in Figure 1(b), the demand for electricity caused by charging electric vehicles would shift to the late-night hours, thus suppressing the peak demand that occurs in the evening.

[0014] Incidentally, the spread of solar power generation systems has been remarkable in recent years. When solar power generation systems are installed on a large scale, as shown in Figure 1(c), on sunny days, the electricity supplied by solar power generation systems (corresponding to "PV" in Figure 1(c)) reduces daytime demand, resulting in a daytime bottom in demand (idle power generation equipment). In that case, for power generation companies, it is desirable that on sunny days, the charging of electric vehicles is shifted to the daytime, increasing daytime demand. As shown in Figure 1(d), if the charging of electric vehicles is shifted to the daytime, the difference between the peak and bottom of demand will be reduced.

[0015] However, if a Tour of the Day (TOU) rate is in place, there is no cost advantage for users in charging electric vehicles during the daytime. Therefore, it is difficult to shift electric vehicle charging to daytime. If a flat rate is in place, electricity rates do not fluctuate depending on the time of day, so the situation will be as shown in Figure 1(a) regardless of the weather. Therefore, in this case as well, it is difficult to shift electric vehicle charging to daytime.

[0016] Incidentally, by installing two electricity meters at the customer's location, a configuration can be considered in which a TOU (Time-of-Operate) charge is applied to the charging of electric vehicles and a flat rate is applied to other loads. Figure 2 shows an example of the installation of two electricity meters, in which electricity meter M1 measures the power consumption of the load, and electricity meter M2 measures the power consumption of the electric vehicle charging system.

[0017] In this configuration, when the power generated by the solar power generation system (corresponding to "PV" in Figure 2) is supplied to the charging system, there is a problem that the power generated and supplied to the charging system (i.e., the power generated and consumed on-site) is measured as purchased power. Also, if the Tour of the Uniform (TOU) charge for the charging system is abandoned and a flat rate (a conventional configuration with one power meter) is adopted, and the power generated by the solar power generation system is used for the charging system, the cost of charging electric vehicles on sunny days can be lower than when a TOU charge is adopted. However, on rainy days, there is a disadvantage in that charging must be done at a flat rate that is higher than the nighttime rate under the TOU charge.

[0018] Therefore, the inventors have devised a power management system that allows for the adoption of TOU (Time-of-Operate) pricing for electric vehicle charging and also allows for shifting electric vehicle charging to daytime hours on sunny days. In other words, the inventors have devised a power management system that benefits both power generators and consumers.

[0019] The embodiments of such a power management system will be described in detail below with reference to the drawings. Note that the embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit the present invention. Furthermore, components in the following embodiments that are not described in an independent claim will be described as optional components.

[0020] Please note that each figure is a schematic diagram and not necessarily a strictly accurate representation. Furthermore, in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0021] (Embodiment) [Configuration] First, the configuration of the power management system according to the embodiment will be described. Figure 3 is a diagram showing the configuration of the power management system according to the embodiment.

[0022] The power management system 10 shown in Figure 3 is a system for managing electricity at a customer 90. As shown in Figure 3, the power management system 10 comprises a solar power generation system 21, a power conditioner 22, a sensor 23, a battery storage system 24, a charging system 25, an electric vehicle 26, a load 27, a first power meter 28a, a second power meter 28b, and a management device 30. The solar power generation system 21, power conditioner 22, sensor 23, battery storage system 24, charging system 25, electric vehicle 26, load 27, first power meter 28a, and second power meter 28b are installed at the customer 90.

[0023] The photovoltaic power generation system 21 is a power generation system that generates electricity by converting sunlight into electrical energy, and is an example of a distributed power source installed at a consumer 90. The electricity generated by the photovoltaic power generation system 21 is output to the power conditioner 22. Specifically, the photovoltaic power generation system 21 is implemented using PV (PhotoVoltaic) panels, etc.

[0024] The power conditioner 22 is a power conversion device that converts DC power generated by the solar power generation system 21 into AC power, and is sometimes called a PCS (Power Conditioning System). The power conditioner 22 is realized by power conversion circuits such as a DC-DC converter and a DC-AC converter. The power conditioner 22 is installed at the consumer 90. The power conditioner 22 can output (supply) the power generated by the solar power generation system 21 to the load 27.

[0025] Furthermore, the power conditioner 22 can output (supply) the power generated by the solar power generation system 21 to the charging system 25 using the path shown in Figure 3(a), and this power is measured by the first power meter 28a. At this time, the power conditioner 22 uses the sensor 23 to adjust the power output from the power conditioner 22 (solar power generation system 21) so that reverse power flow from the consumer 90 to the power grid 80 does not occur. In other words, the power conditioner 22 adjusts the power output from the power conditioner 22 so that the power output from the solar power generation system 21 is supplied to the charging system 25 without reverse power flow to the power grid 80.

[0026] Sensor 23 is a current sensor located on the main line connecting the power system 80 and the consumer 90, and measures current. Sensor 23 is located on the power system 80 side of the branching point between the path from the power system 80 to the first power meter 28a and load 27 and the path from the power system 80 to the second power meter 28b and charging system 25. Sensor 23 is implemented, for example, by a CT (Current Transformer).

[0027] The battery storage system 24 is a system that functions as a power source at the consumer 90. The battery storage system 24 is realized by a secondary battery such as a lithium-ion battery, a charging circuit for charging the secondary battery, and a discharge circuit for discharging the secondary battery. The secondary battery is charged, for example, by the power generated by the solar power generation system 21.

[0028] The charging system 25 is a device that consumes electricity and is installed at the customer 90, and is an example of a second electrical device. The charging system 25 charges the electric vehicle 26 (more specifically, the battery 26a provided in the electric vehicle 26) using AC power obtained from the power grid 80 or the solar power generation system 21 (power conditioner 22). Specifically, the charging system 25 includes a charger body 25a including a charging cable and a charging connector, which outputs power suitable for charging the battery provided in the electric vehicle 26 to the electric vehicle 26, and a charging control device 25b which controls the amount of charge by the charger body 25a, etc.

[0029] The charging control device 25b is composed of a microcomputer and memory, etc. The functions of the charging control device 25b are realized, for example, by the microcomputer executing a computer program stored in the memory. Note that the charging control device 25b may be a device outside the charging system 25 (a device separate from the charger body 25a).

[0030] The electric vehicle 26 is a vehicle used by a user belonging to customer 90. The electric vehicle 26 is, for example, an EV (Electric Vehicle) that runs on the power of a motor, but it may also be a vehicle that runs using both an engine and a motor, such as a PHV (Plug-in Hybrid Vehicle) or PHEV (Plug-in Hybrid EV). The electric vehicle 26 is equipped with a storage battery 26a as an energy source for the electric vehicle 26 to run. The storage battery 26a is a secondary battery such as a lithium-ion battery.

[0031] Load 27 is an appliance installed at customer 90 that consumes electricity, and is an example of a first electrical appliance. Load 27 includes lighting equipment, air conditioning equipment, ventilation equipment, refrigerators, and televisions.

[0032] The first power meter 28a is located on the first path, which is one of the paths branching off from the main line (power system 80) that connects the main line and the load 27, and measures the first power (power flowing from top to bottom in Figure 3) supplied from the power system 80 to the load 27. The first power meter 28a can also measure the power output (supplied) from the solar power generation system 21 (power conditioner 22) to the charging system 25 via the path shown in Figure 3(a). This power flows from bottom to top in Figure 3, and hereafter this power will also be referred to as power in the opposite direction to the first power. The first power meter 28a also communicates with the management device 30 and transmits the measured values ​​of the first power and the measured values ​​of the power in the opposite direction to the management device 30.

[0033] The first power meter 28a is, for example, a specified measuring instrument (a measuring instrument that has undergone verification as stipulated in the Measurement Act), such as a smart meter, but it may also be an exceptional measuring instrument (a measuring instrument that has not undergone verification as stipulated in the Measurement Act), or it may also be any other measuring instrument other than a specified measuring instrument or an exceptional measuring instrument (a measuring instrument that has not undergone verification as stipulated in the Measurement Act).

[0034] The second power meter 28b is located on a second path that connects the main line (power grid 80) and the charging system 25, and is one of the other paths branching off from the main line. It measures the second power (power flowing from top to bottom in Figure 3) supplied from the power grid 80 to the charging system 25. The second power meter 28b also measures the power output (supplied) from the solar power generation system 21 (power conditioner 22) to the charging system 25 as the second power through the path shown in Figure 3(a). The second power meter 28b also communicates with the management device 30 to transmit the measured value of the second power to the management device 30. The second power meter 28b is a specific measuring instrument such as a smart meter, but it may also be an exceptional measuring instrument, or any other measuring instrument other than a specific measuring instrument or an exceptional measuring instrument.

[0035] The management device 30 calculates the electricity charge to the customer 90 based on the measured values ​​of the first power and the reverse power received from the first power meter 28a, and the measured values ​​of the second power received from the second power meter 28b. The management device 30 is used, for example, by a retail electricity provider. The management device 30 is implemented, for example, by a server device (cloud server) located away from the customer 90, but may also be implemented as a device located within the customer 90. The management device 30 comprises a communication unit 31, an information processing unit 32, and a storage unit 33.

[0036] The communication unit 31 is a communication circuit for the management device 30 to communicate with the first power meter 28a, the second power meter 28b, and the information terminal 40 via a wide-area communication network. The communication unit 31 may, for example, perform wired communication, but it may also perform wireless communication. There are no particular limitations on the communication standards used by the communication unit 31.

[0037] The information processing unit 32 performs information processing to calculate the electricity charges for the customer 90. The information processing unit 32 is implemented by, for example, a microcomputer, but may also be implemented by a processor. The information processing unit 32 includes, as functional components, a first acquisition unit 34, a second acquisition unit 35, a calculation unit 36, and an output unit 37. The functions of the first acquisition unit 34, the second acquisition unit 35, the calculation unit 36, and the output unit 37 are realized, for example, by the microcomputer or processor constituting the information processing unit 32 executing a computer program stored in the storage unit 33.

[0038] The storage unit 33 is a storage device that stores information (such as computer programs) necessary for information processing performed by the information processing unit 32. The storage unit 33 is implemented by, for example, an HDD (Hard Disk Drive), but may also be implemented by semiconductor memory.

[0039] The information terminal 40 is an information terminal used by users (people) belonging to the customer 90 to receive notifications regarding electricity charges. The information terminal 40 is a portable information terminal such as a smartphone or tablet, but it may also be a stationary information terminal such as a personal computer. The information terminal 40 is equipped with a display unit 41.

[0040] The display unit 41 displays electricity charges and the like. The display unit 41 is implemented by a display panel such as a liquid crystal panel or an organic EL (Electroluminescence) panel.

[0041] [Unit Price Information] The storage unit 33 of the management device 30 stores in advance unit price information that shows the unit price of electricity charges for the measured values ​​of the first power meter 28a and the second power meter 28b. Figure 4 is a diagram illustrating an example of the unit price of electricity charges shown in the unit price information. Figure 4 schematically shows the fluctuation of the unit price of electricity charges over one day (24 hours).

[0042] Figure 4(a) shows the electricity rate per unit (hereinafter also referred to as the first electricity purchase price) for the first power supplied from the power system 80 to the load 27. The first electricity purchase price is, for example, constant (Y yen) regardless of the time of day. In other words, a uniform rate is applied to the first power. As described above, the first power is measured by the first power meter 28a.

[0043] Figure 4(b) shows the electricity rate per unit for the second power supplied from the power grid 80 to the charging system 25 (hereinafter also referred to as the second electricity purchase rate). The second electricity purchase rate is, for example, Z (<Y) yen during the time period from t1 to t2 of the day, and X (>Y) yen during other time periods. In other words, the TOU rate is applied to the second power. As described above, the second power is measured by the second power meter 28b.

[0044] Here, when the generated power of the photovoltaic power generation system 21 is output to the charging system 25 via the path in (a) of FIG. 3, the generated power ends up being measured by the second power meter 28b. That is, when the generated power of the photovoltaic power generation system 21 is output to the charging system 25, the same electricity rate as the second power is charged for the generated power at the consumer 90 (as if the power were purchased from the power system 80).

[0045] Accordingly, the management device 30 treats the charging generated power, which is the generated power of the photovoltaic power generation system 21 output to the charging system 25 (that is, the power in the opposite direction to the first power, measured by the first power meter 28a), as power that has been sold. In other words, a virtual power selling unit price (hereinafter also referred to as the virtual feed-in tariff) is set for the charging generated power. (c) of FIG. 4 shows the virtual feed-in tariff, which is, for example, Z (<Y) yen in the time period from time t1 to t2 within a day, and X (>Y) yen in the other time periods. That is, the virtual feed-in tariff has the same amount per time period as the second power purchase unit price.

[0046] If the electricity rate unit prices are set in this way, when calculating the electricity bill, if (measured value of the second power meter 28b × Z yen) is charged for the charging generated power, (measured value of the first power meter 28a × Z yen) is refunded, and the cost for the charging generated power is offset (becomes 0 yen). In other words, although the charging generated power (self-consumed power) ends up being metered as purchased power by the second power meter 28b, it is not treated as purchased power in terms of cost.

[0047] Therefore, the consumer 90 can reduce the charging cost by using the generated power of the photovoltaic power generation system 21 to charge the electric vehicle 26 while the TOU tariff is applied to the charging of the electric vehicle 26. That is, the consumer 90 is given an incentive to shift the charging of the electric vehicle 26 to the daytime on sunny days.

[0048] As such, the power management system 10 can adopt the TOU tariff for electric vehicle charging, and can shift electric vehicle charging to the daytime on sunny days.

[0049] In the power management system 10, the output (sale of electricity) of electricity from the customer 90 to the power grid 80 is prohibited by contract between the customer 90 and the retail electricity provider. For this reason, the power conditioner 22 adjusts the output of electricity from the power conditioner 22 (solar power generation system 21) to the charging system 25 so that reverse power flow from the customer 90 to the power grid 80 does not occur. Consequently, no electricity is output from the customer 90 to the power grid 80, and all electricity in the opposite direction to the first power measured by the first power meter 28a can be considered as power generated for charging supplied to the charging system 25.

[0050] [Example 1 of electricity charge calculation operation] Next, we will explain the operation of calculating electricity charges for customers 90 in the power management system 10. Figure 5 is a flowchart of Example 1 of the operation of calculating electricity charges for customers 90.

[0051] The first acquisition unit 34 of the management device 30 communicates with the first power meter 28a using the communication unit 31 to acquire the first measured value of the first power supplied from the power system 80 to the load 27, and the measured value of the power generated for charging, as measured by the first power meter 28a (S11).

[0052] Next, the second acquisition unit 35 communicates with the second power meter 28b using the communication unit 31 to acquire the second measured value of the second power supplied from the power system 80 to the charging system 25, which is measured by the second power meter 28b (S12).

[0053] Next, the calculation unit 36 ​​calculates the electricity charges for the customer 90 based on the first measured value and the measured value of the power generated for charging acquired in step S11, the second measured value acquired in step S12, and the first electricity purchase price, the second electricity purchase price, and the virtual electricity sales price indicated by the unit price information stored in the storage unit 33 (S13). More specifically, the calculation unit 36 ​​applies the first electricity purchase price to the first measured value for a predetermined period such as one month, applies the second electricity purchase price to the second measured value for a predetermined period, applies the virtual electricity sales price to the measured value of the power generated for charging for a predetermined period, and calculates the electricity charges for the customer 90 for a predetermined period by summing these up.

[0054] Furthermore, the sum of the amount obtained by applying the first electricity purchase price to the first measured value and the amount obtained by applying the second electricity purchase price to the second measured value is treated as an expense for consumer 90, while the amount obtained by applying the virtual electricity sales price to the measured value of the power generated for charging is treated as income for consumer 90.

[0055] Next, the output unit 37 transmits (outputs) electricity bill notification information showing the calculated electricity bill to the information terminal 40 using the communication unit 31 (S14). The display unit 41 of the information terminal 40, which has received the electricity bill notification information, displays the electricity bill calculated in step S13.

[0056] In this way, the management device 30 can calculate the electricity charges for the customer 90. As described above, since the virtual electricity selling price is set to be the same as the second electricity purchasing price, the cost of the electricity generated for charging is offset (becomes 0 yen) when calculating the electricity charges. Therefore, the customer 90 can reduce charging costs by using the electricity generated by the solar power generation system 21 to charge the electric vehicle 26 while still being subject to the TOU rate for charging the electric vehicle 26.

[0057] [Method for Determining Charging Power] The method for determining the charging power of the electric vehicle 26 using the charging control device 25b will be described below. The electric vehicle 26 is charged using surplus power from the solar power generation system 21, and the charging power of the electric vehicle 26 is equivalent to the surplus power.

[0058] For example, if the power conditioner 22 is discharging excess power to the ground, a first measuring device is provided to measure the power in the ground wire connecting the power conditioner 22 to the ground. The first measuring device may be an appliance included in the power conditioner 22, or it may be a separate appliance from the power conditioner 22.

[0059] In this case, the charging control device 25b communicates with the first measuring device to determine which electricity generated by the solar power generation system 21 is wasted on the ground, and can charge the electric vehicle 26 by considering this electricity as surplus power.

[0060] Furthermore, when the power conditioner 22 is charging the battery storage system 24 with surplus power, a second measuring device is provided to measure the charging power of the battery storage system 24. The second measuring device may be an instrument included in the power conditioner 22, an instrument included in the battery storage system 24, or an instrument separate from both the power conditioner 22 and the battery storage system 24.

[0061] In this case, the charging control device 25b communicates with the second measuring device to determine which of the power generated by the solar power generation system 21 is used to charge the battery storage system 24, and can then charge the electric vehicle 26 by considering this power as surplus power.

[0062] Furthermore, if the solar power generation system 21 is equipped with multi-string PV panels and the power conditioner 22 limits the output on a string-by-string basis when surplus power is generated, the difference in power generation between strings can be considered as surplus power. Therefore, a third measuring device is provided to measure the difference in power generation between strings. The third measuring device may be an instrument included in the solar power generation system 21, an instrument included in the power conditioner 22, or an instrument separate from both the solar power generation system 21 and the power conditioner 22.

[0063] In this case, the charging control device 25b communicates with the third measuring device to grasp the difference in generated power between the strings, and can charge the electric vehicle 26 by considering the difference in generated power as surplus power.

[0064] Furthermore, when the power conditioner 22 controls the supply of X [W] of power from the power grid 80 to the customer 90, the charging control device 25b may attempt to charge the electric vehicle 26 so that Y [W] of power, which is greater than X, is supplied from the power grid 80 to the customer 90. However, the power demand at the customer 90 is assumed to be greater than X. In this way, the charging control device 25b can draw the surplus power to the charging system 25 and use the surplus power to charge the electric vehicle 26.

[0065] Furthermore, the charging control device 25b can monitor the power supplied from the power system 80 to the customer 90 using a sensor (similar to the sensor 23) that measures the current between the power system 80 and the customer 90 (attempting to charge the electric vehicle 26 so that Y [W] of power is supplied).

[0066] [Method for transmitting measured values] The method for transmitting measured values ​​from the first power meter 28a and the second power meter 28b to the control device 30 will be explained below.

[0067] Generally, the first power meter 28a and the second power meter 28b each transmit power measurement values, for example, with a minimum unit of 30 minutes, to the management device 30. However, in order to reduce the error in the measurement values, the measurement values ​​may be transmitted as follows.

[0068] In the following, it is assumed that the first power meter 28a and the second power meter 28b can communicate with each other. Furthermore, the measured values ​​of the first power meter 28a below include the first measured value and the measured value of the power generated for charging, and the measured values ​​of the second power meter 28b include the second measured value.

[0069] The first power meter 28a and the second power meter 28b each measure power consumption at time intervals shorter than 30 minutes, such as one minute, and store (accumulate) the data in the memory unit within the power meter. When the first power meter 28a (master unit) has accumulated 30 minutes' worth of measurement data, it acquires (receives) the most recent 30 minutes' worth of measurement data from the second power meter 28b. As a result, the measurement data of the first power meter 28a and the measurement data of the second power meter 28b are synchronized.

[0070] The first power meter 28a transmits to the management device 30 the measurement value corresponding to the most recent 30 minutes of the second power meter 28b, which it has acquired, and the measurement value corresponding to the most recent 30 minutes of the first power meter 28a. This allows the management device 30 to acquire measurement values ​​with minimal time discrepancies.

[0071] The above is an example in which the first power meter 28a functions as the master unit, acquires the measured value from the second power meter 28b (which is the slave unit), and transmits it to the management device 30. Conversely, the second power meter 28b may function as the master unit, acquire the measured value from the first power meter 28a (which is the slave unit), and transmit it to the management device 30. In other words, one of the power meters, the first power meter 28a and the second power meter 28b, can communicate with the other power meter to acquire the measured value from the other power meter for a predetermined period (for example, the most recent 30 minutes), and then transmit the acquired measured value from the other power meter for the predetermined period along with the measured value from the first power meter for the predetermined period.

[0072] Alternatively, an auxiliary device (not shown) different from either the first power meter 28a or the second power meter 28b may acquire the most recent measurement value from the first power meter 28a and the most recent measurement value from the second power meter 28b and transmit it to the management device 30.

[0073] The auxiliary device is, for example, an EMS controller installed at the customer 90, but is not particularly limited. For example, the auxiliary device may be incorporated into the power conditioner 22, and the acquired measurement values ​​may be used to control the power conditioner 22.

[0074] [Notification of Reverse Power Flow Occurrence] Incidentally, if the measured value of the power generated for charging and the second measured value are synchronized, when comparing the measured value of the power generated for charging and the second measured value over the same period, the measured value of the power generated for charging will be less than or equal to the second measured value. This is because reverse power flow from the consumer 90 to the power grid 80 is prohibited, and the power conditioner 22 uses the sensor 23 to adjust the power output from the power conditioner 22 so that reverse power flow from the consumer 90 to the power grid 80 does not occur.

[0075] If there is a period during which the measured value of the power generated for charging is greater than the second measured value, it can be considered that a reverse power flow is occurring from the consumer 90 to the power grid 80 during that period. In other words, it can be considered that the consumer 90 is in violation of its contract with the retail electricity provider, etc.

[0076] Therefore, the management device 30 may notify (warn) users belonging to the consumer 90 if it detects that there is a period in which the measured value of the power generated for charging > the second measured value. For example, if the output unit 37 determines, based on the measured value of the power generated for charging acquired by the first acquisition unit 34 and the second measured value acquired by the second acquisition unit 35, that there is a period in which the measured value of the power generated for charging > the second measured value, it transmits (outputs) notification information indicating that reverse power flow has occurred to the information terminal 40 using the communication unit 31. The display unit 41 of the information terminal 40 that receives the notification information displays a notification screen indicating that reverse power flow has occurred.

[0077] In this way, the management device 30 can notify users belonging to the consumer 90 that reverse power flow has occurred.

[0078] [Example 2 of electricity bill calculation operation] It was explained that the power management system 10 does not allow reverse power flow (in other words, selling electricity) from the customer 90 to the power grid 80. In contrast, the following describes the electricity bill calculation operation (Example 2 of calculation operation) when reverse power flow (selling electricity) is allowed. In Example 2 of electricity bill calculation operation, the power management system 10 is equipped with a third power meter 28c in the same position as the sensor 23, in place of the sensor 23 (or in addition to the sensor 23), which measures the power that flows in reverse from the customer 90 to the power grid 80 (hereinafter also referred to as reverse power flow power). Figure 6 is a diagram showing the configuration of the power management system 10 equipped with the third power meter 28c.

[0079] The third power meter 28c is located on the main line connecting the power system 80 and the consumer 90, and is a power meter that measures reverse power flow. The third power meter 28c also communicates with the management device 30 and transmits the measured value of reverse power flow to the management device 30. The third power meter 28c is a specified measuring instrument such as a smart meter, but it may also be an exceptional measuring instrument, or any other measuring instrument other than a specified measuring instrument or an exceptional measuring instrument.

[0080] Figure 7 is a flowchart of Example 2 of the calculation operation for electricity charges for customer 90. The first acquisition unit 34 of the management device 30 communicates with the first power meter 28a using the communication unit 31 to acquire the first measured value of the first power supplied from the power system 80 to the load 27, and the measured value of the generated power, as measured by the first power meter 28a (S21). The generated power here differs from the generated power for charging and refers to the sum of the reverse power flow power and the generated power for charging.

[0081] Next, the second acquisition unit 35 communicates with the second power meter 28b using the communication unit 31 to acquire the second measured value of the second power supplied from the power system 80 to the charging system 25, which is measured by the second power meter 28b (S22).

[0082] Next, the calculation unit 36 ​​communicates with the third power meter 28c using the communication unit 31 to acquire the measured value of the reverse power flow measured by the third power meter 28c (S23). Note that the processing in step S23 may be performed by a third acquisition unit (not shown), which is a functional component of the information processing unit 32.

[0083] Next, the calculation unit 36 ​​calculates the electricity charge for the customer 90 based on the first measured value and the measured value of generated power acquired in step S21, the second measured value acquired in step S22, the measured value of reverse power flow acquired in step S23, and the first electricity purchase price, second electricity purchase price, virtual electricity sales price, and adjustment price indicated by the unit price information stored in the storage unit 33 (S24).

[0084] As described above, in Example 2 of the electricity bill calculation process, the generated power includes both reverse power flow power and power generated for charging. Similar to Example 1 of the electricity bill calculation process, if a virtual electricity sales price is applied to the measured value of generated power, the virtual electricity sales price will be applied not only to the power generated for charging but also to the reverse power flow power. Therefore, it is necessary to adjust (correct) the reverse power flow power to the actual electricity sales price. The adjustment price is the information used for this adjustment (correction).

[0085] Figure 8 is a diagram illustrating the adjustment price. Figure 8(a) shows the actual electricity selling price, Figure 8(b) shows the virtual electricity selling price, and Figure 8(c) shows the adjustment price. As shown in Figure 8, the adjustment price is the value obtained by subtracting the virtual electricity selling price from the actual electricity selling price of reverse power flow. As a result, the sum of the amount obtained by applying the adjustment price to the measured value of reverse power flow and the amount obtained by applying the virtual electricity selling price to the measured value of generated power is equal to the sum of the amount obtained by applying the actual electricity selling price to the measured value of reverse power flow and the amount obtained by applying the virtual electricity selling price to the measured value of generated power for charging.

[0086] In step S24, the calculation unit 36 ​​more specifically applies the first electricity purchase price to the first measured value for a predetermined period such as one month, applies the second electricity purchase price to the second measured value for a predetermined period, applies the virtual electricity sales price to the measured value of generated power for a predetermined period, applies the adjustment price to the measured value of reverse power flow, and calculates the electricity charges for the customer 90 for a predetermined period by summing these up.

[0087] Next, the output unit 37 transmits (outputs) electricity bill notification information showing the calculated electricity bill to the information terminal 40 using the communication unit 31 (S25). The display unit 41 of the information terminal 40, which has received the electricity bill notification information, displays the electricity bill calculated in step S24.

[0088] In this way, the management device 30 can appropriately calculate the electricity charges to the customer 90 even when reverse power flow from the customer 90 to the power grid 80 (in other words, selling electricity) is permitted.

[0089] Alternatively, a method for calculating electricity charges that does not use measured values ​​of generated power or virtual electricity sales prices can be considered. For example, the calculation unit 36 ​​can apply a first electricity purchase price to the first measured values ​​for a predetermined period, apply a second electricity purchase price to the second measured values ​​for a predetermined period, apply the actual electricity sales price (Figure 8(a)) to the measured values ​​of reverse power flow, and then sum these up to calculate the electricity charges for the customer 90 for a predetermined period. In this case, the management device 30 does not need to acquire measured values ​​of generated power.

[0090] Furthermore, the power management system 10 may selectively switch between a first mode of operation, which calculates electricity charges without allowing reverse power flow to the power grid 80, and a second mode of operation, which calculates electricity charges while allowing reverse power flow to the power grid 80. The first mode of operation corresponds to Example 1 of the electricity charge calculation operation, and the second mode of operation corresponds to Example 2 of the electricity charge calculation operation.

[0091] [Modified Configuration] Next, the configuration of the power management system according to the modified configuration will be described. Figure 9 is a diagram showing the configuration of the power management system according to the modified configuration.

[0092] The power management system 10a shown in Figure 9 includes a first sensor 23a and a second sensor 23b instead of the sensor 23. The first sensor 23a is located between the first power meter 28a and the load 27 and measures the current. The second sensor 23b is located between the second power meter 28b and the charging system 25 and measures the current.

[0093] In the power management system 10a, the power conditioner 22 can detect the current between the customer 90 and the power system 80 (reverse power flow from the customer 90 to the power system 80) by comparing the measured value of the first sensor 23a with the measured value of the second sensor 23b. In other words, the power conditioner 22 can use the first sensor 23a and the second sensor 23b instead of the sensor 23.

[0094] Such a configuration is useful in cases where the sensor 23 cannot be installed on the power system 80 side of the first power meter 28a and the second power meter 28b (for example, when the installation of the sensor 23 is not permitted by a retail electricity provider). Although not shown, in a power management system 10 equipped with a third power meter 28c (Figure 6), a configuration comprising a first sensor 23a and a second sensor 23b may be adopted instead of the sensor 23.

[0095] [Other Modifications] In the above embodiment, the second electrical equipment to which the second power is supplied is described as being supplied to the charging system 25, but it may be equipment other than the charging system 25. The second electrical equipment may be, for example, a heat pump water heater or a battery storage system. Furthermore, the second electrical equipment may include multiple types of equipment, for example, the charging system 25 and the heat pump water heater.

[0096] In the above embodiment, the distributed power source provided by the power management system 10 was described as a solar power generation system 21. However, the distributed power source provided by the power management system 10 may be a wind power generation system, a hydroelectric power generation system, a geothermal power generation system, or a biomass power generation system, etc. Furthermore, the power management system 10 may be equipped with multiple types of devices (systems) as distributed power sources.

[0097] In the above embodiment, it was explained that the first electricity purchase price set for the first power company is constant regardless of the time of day (a uniform first pricing system), and the second electricity purchase price set for the second power company fluctuates according to the time of day (a time-of-use pricing system). However, the first and second electricity purchase prices can be different. For example, one of the first and second electricity purchase prices may be based on a dynamic pricing system in which the price fluctuates daily and by time of day.

[0098] It should be noted that both the Time of Use (TOU) pricing system and dynamic pricing systems are pricing systems in which the unit price of electricity purchased fluctuates depending on the time of day. However, the TOU pricing system differs from dynamic pricing in that the unit price of electricity purchased does not change depending on the daily supply and demand situation of electricity. The unit price of electricity purchased under the TOU pricing system is predetermined, for example, by contract.

[0099] [Effects, etc.] Below, examples of inventions obtained from the disclosures of this specification will be given, and the effects, etc. obtained from said inventions will be explained.

[0100] Invention 1 is a power management system 10 installed at a consumer 90 that manages the power of a first electrical device, a second electrical device, and a distributed power source, comprising: a first acquisition unit 34 that acquires a first measured value of the first power supplied from the power system 80 to the first electrical device, measured by a first measuring instrument, and a measured value of power output from a distributed power source in the opposite direction to the first power; a second acquisition unit 35 that acquires a second measured value of the second power supplied from the power system 80 to the second electrical device, measured by a second measuring instrument different from the first measuring instrument; and a calculation unit 36, wherein the power output from the distributed power source is measured between the consumer 90 and the power system 80 A sensor 23 for measuring the current between zero is used to adjust so that reverse power does not flow back into the power grid 80. A first electricity purchase price is set for the first power, a second electricity purchase price different from the first electricity purchase price is set for the second power, and a virtual electricity sales price, which is the same as the second electricity purchase price, is set for reverse power to be treated as if reverse power had been sold. The calculation unit 36 ​​calculates the electricity charges to the consumer 90 based on the first measured value, the measured value of the reverse power, and the second measured value, as well as the first electricity purchase price, the second electricity purchase price, and the virtual electricity sales price. The load 27, charging system 25, solar power generation system 21, first power meter 28a, and second power meter 28b in the above embodiment are examples of the first electrical equipment, second electrical equipment, distributed power source, first measuring instrument, and second measuring instrument.

[0101] In such a power management system 10, although the electricity consumed by the second electrical equipment (reverse power) is measured by the second measuring instrument and subject to billing, the charge for the consumed electricity is offset by the fact that a virtual electricity sales price is set for the consumed electricity. Therefore, the power management system 10 can calculate electricity charges in such a way that the consumed electricity is not treated as purchased electricity.

[0102] Invention 2 is a power management system 10 of Invention 1, in which the sensor 23 is located on the power system 80 side of the first measuring instrument and the second measuring instrument.

[0103] Such a power management system 10 can suppress reverse power flow from the consumer 90 to the power grid 80 using a single sensor 23.

[0104] Invention 3 is the power management system 10 of Invention 1, wherein the sensor 23 includes a first sensor 23a located between a first measuring instrument and a first electrical device, and a second sensor 23b located between a second measuring instrument and a second electrical device.

[0105] Such a power management system 10 can suppress reverse power flow from the customer 90 to the power grid 80 by using a first sensor 23a and a second sensor 23b that are located on the customer 90 side of the first and second measuring instruments.

[0106] Invention 4 is a power management system 10 according to any of Inventions 1 to 3, wherein the second electrical device is a charging system 25 for an electric vehicle 26, and the power management system 10 includes a charging control device 25b that controls the charging of the electric vehicle 26, and the charging control device 25b charges the electric vehicle 26 using surplus power from a distributed power source.

[0107] Such a power management system 10 can calculate electricity charges in such a way that surplus electricity used to charge the electric vehicle 26 is not treated as purchased electricity.

[0108] Invention 5 is a power management system 10 of Invention 4, wherein the charging control device 25b considers the electricity generated by distributed power sources that is wasted on the ground as surplus power.

[0109] Such a power management system 10 can charge an electric vehicle 26 using electricity generated by distributed power sources that would otherwise be wasted on the ground.

[0110] Invention 6 is a power management system 10 of Invention 4, wherein the charging control device 25b considers the power that is charged to the battery system 24 from the power generated by the distributed power source as surplus power.

[0111] Such a power management system 10 can charge an electric vehicle 26 using electricity that is scheduled to be charged into the battery storage system 24 from the electricity generated by distributed power sources.

[0112] Invention 7 is a power management system 10 of Invention 4, wherein the distributed power source has multi-string type PV panels, and the charging control device 25b considers the difference in generated power between strings as surplus power.

[0113] Such a power management system 10 can charge an electric vehicle 26 using power that is scheduled to be suppressed in a multi-string type PV panel.

[0114] Invention 8 is a power management system 10 of Invention 4, wherein the charging control device 25b charges the electric vehicle 26 using surplus power by charging the electric vehicle 26 so that a power of Y [W] greater than X is supplied from the power system 80 to the consumer 90 when the power system 80 is controlled by another device to supply X [W] of power to the consumer 90.

[0115] Such a power management system 10 can charge the electric vehicle 26 using surplus power.

[0116] Invention 9 is a power management system 10 according to any of Inventions 1 to 8, wherein the power management system 10 can perform a first mode of operation in which the power output from distributed power sources is adjusted so that reverse power does not flow back into the power grid 80, and a second mode of operation in which reverse power flow into the power grid 80 is permitted, and the calculation unit 36 ​​calculates the electricity charge during the operation of the second mode based on a first measured value, a measured value of reverse power, a second measured value, a first electricity purchase price, a second electricity purchase price, a virtual electricity sales price, a measured value of the reverse-flowed power, and an adjustment price set for the reverse-flowed power, and the adjustment price is the value obtained by subtracting the virtual electricity sales price from the electricity sales price of the reverse-flowed power.

[0117] Such a power management system 10 can calculate electricity charges in a way that ensures that electricity consumed internally is not treated as purchased electricity, even when reverse power flow from the consumer 90 to the power grid 80 is permitted.

[0118] Invention 10 is a power management system 10 according to any of Inventions 1 to 8, wherein the power management system 10 can perform a first mode of operation in which the power output from distributed power sources is adjusted so that reverse power does not flow back into the power grid 80, and a second mode of operation in which reverse power flow into the power grid 80 is permitted, and the calculation unit 36 ​​calculates the electricity charge to the consumer 90 based on the first measurement value, the second measurement value, the measurement value of the reverse-flowing power, the first purchase price, the second purchase price, and the purchase price set for the reverse-flowing power, without using the measured value of the reverse-flowing power and the virtual electricity sales price during the operation of the second mode,

[0119] Such a power management system 10 can calculate electricity charges in a way that ensures that electricity consumed internally is not treated as purchased electricity, even when reverse power flow from the consumer 90 to the power grid 80 is permitted.

[0120] Invention 11 is a power management system 10 according to any of Inventions 1 to 10, wherein one of the first measuring instrument and the second measuring instrument communicates with the other measuring instrument to acquire the measured value of the other measuring instrument over a predetermined period, and transmits the acquired measured value of the other measuring instrument over the predetermined period and the measured value of one of the measuring instruments over the predetermined period, the first acquisition unit 34 acquires the first measured value over the predetermined period and the measured value of the reverse power over the predetermined period transmitted by one of the measuring instruments, and the second acquisition unit 35 acquires the second measured value over the predetermined period transmitted by one of the measuring instruments.

[0121] Such a power management system 10 can calculate electricity charges based on measured values ​​transmitted by one of the measuring instruments.

[0122] Invention 12 is a power management system 10 according to any of Inventions 1 to 10, wherein an auxiliary device different from both the first and second measuring instruments communicates with each of the first and second measuring instruments to acquire a first measurement value, a reverse power measurement value, and a second measurement value for a predetermined period, and transmits the acquired first measurement value, reverse power measurement value, and second measurement value for the predetermined period; the first acquisition unit 34 acquires the first measurement value and the reverse power measurement value for the predetermined period transmitted by the auxiliary device; and the second acquisition unit 35 acquires the second measurement value for the predetermined period transmitted by the auxiliary device.

[0123] Such a power management system 10 can calculate electricity charges based on measured values ​​transmitted by an auxiliary device.

[0124] Invention 13 is a power management system 10 according to any of Inventions 1 to 12, wherein the first electricity purchase price is constant regardless of the time of day, and the second electricity purchase price and the virtual electricity sales price fluctuate according to the time of day.

[0125] Such a power management system 10 can calculate electricity charges in a way that prevents self-consumed electricity from being treated as purchased electricity, where the unit price of electricity fluctuates depending on the time of day.

[0126] Invention 14 is a power management method to be performed by a power management system 10 installed at a consumer 90, which manages the power of a first electrical device, a second electrical device, and a distributed power source, and includes a first acquisition step of acquiring a first measured value of the first power supplied from the power system 80 to the first electrical device, measured by a first measuring instrument, and a measured value of the power output from the distributed power source in the opposite direction to the first power, a second acquisition step of acquiring a second measured value of the second power supplied from the power system 80 to the second electrical device, measured by a second measuring instrument different from the first measuring instrument, and a calculation step, wherein the power output from the distributed power source is calculated by the consumer 9 This power management method uses a sensor 23 to measure the current between 0 and the power grid 80, and adjusts so that reverse power does not flow back into the power grid 80. A first electricity purchase price is set for the first power, a second electricity purchase price different from the first electricity purchase price is set for the second power, and a virtual electricity sales price, which is the same as the second electricity purchase price, is set for reverse power to be treated as if it were sold. In the calculation step, the electricity charges to the consumer 90 are calculated based on the first measured value, the measured value of the reverse power, the second measured value, the first electricity purchase price, the second electricity purchase price, and the virtual electricity sales price.

[0127] In this type of power management method, although the electricity consumed by the second electrical equipment (reverse power) is measured and billed by the second measuring instrument, the charge for the consumed electricity is offset by the fact that a virtual electricity sales price is set for the consumed electricity. Therefore, the power management method can calculate electricity charges in such a way that the consumed electricity is not treated as purchased electricity.

[0128] Invention 15 is a program for causing the power management system 10 to execute the power management method of Invention 14.

[0129] According to such a program, a computer can calculate electricity charges in a way that ensures that electricity consumed at home is not treated as purchased electricity.

[0130] (Other Embodiments) Although embodiments have been described above, the present invention is not limited to the embodiments described above.

[0131] For example, in the above embodiment, the power management system was implemented by multiple devices, but it may also be implemented as a single device. The same applies to other systems such as power management systems. Thus, the systems described herein may consist of a single device or multiple devices. When a system is implemented by multiple devices, the components of the system may be distributed among the multiple devices in any way.

[0132] Furthermore, in the above embodiment, the processing performed by a specific processing unit may be performed by another processing unit. Also, the order of multiple processing units may be changed, or multiple processing units may be executed in parallel.

[0133] Furthermore, in the above embodiment, each component may be realized by executing a software program suitable for each component. Each component may also be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0134] Furthermore, each component may be implemented by hardware. Each component may also be a circuit (or integrated circuit). These circuits may form a single circuit as a whole, or they may be separate circuits. Also, each of these circuits may be a general-purpose circuit or a dedicated circuit.

[0135] Furthermore, general or specific embodiments of the present invention may be implemented as a system, apparatus, method, integrated circuit, computer program, or recording medium such as a computer-readable CD-ROM. Alternatively, they may be implemented as any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

[0136] For example, the present invention may be implemented as an apparatus or system as described in the above embodiments. Alternatively, the present invention may be implemented as a method executed by an apparatus or system (computer or computer system) as described in the above embodiments. The present invention may also be implemented as a program (computer program product) for causing a computer or computer system to execute such a method. The present invention may also be implemented as a computer-readable non-temporary recording medium on which such a program is recorded.

[0137] Furthermore, the present invention also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art could conceive, or forms realized by arbitrarily combining the components and functions of each embodiment without departing from the spirit of the present invention.

[0138] 10, 10a Power Management System 21 Solar Power Generation System (Distributed Power Source) 22 Power Conditioner 23 Sensor 23a First Sensor 23b Second Sensor 24 Battery Storage System 25 Charging System (Second Electrical Equipment) 25a Charger Body 25b Charging Control Device 26 Electric Vehicle 26a Battery 27 Load (First Electrical Equipment) 28a First Power Meter (First Measuring Instrument) 28b Second Power Meter (Second Measuring Instrument) 28c Third Power Meter 30 Management Device 31 Communication Unit 32 Information Processing Unit 33 Storage Unit 34 First Acquisition Unit 35 Second Acquisition Unit 36 ​​Calculation Unit 37 Output Unit 40 Information Terminal 41 Display Unit 80 Power System 90 Consumer

Claims

1. A power management system for managing the power of a first electrical device, a second electrical device, and a distributed power source installed at a consumer, comprising: a first acquisition unit that acquires a first measured value of the first power supplied from the power system to the first electrical device, measured by a first measuring instrument, and a measured value of the power output from the distributed power source in the opposite direction to the first power; a second acquisition unit that acquires a second measured value of the second power supplied from the power system to the second electrical device, measured by a second measuring instrument different from the first measuring instrument; and a calculation unit, wherein the power output from the distributed power source is adjusted so that the reverse power does not flow back into the power system using a sensor for measuring the current between the consumer and the power system; a first electricity purchase price is set for the first power; and a second electricity purchase price different from the first electricity purchase price is set for the second power. A power management system is set for the reverse power, which is a virtual electricity selling price that is the same as the second electricity purchase price, for treating the reverse power as if it had been sold, and the calculation unit calculates the electricity charges to the customer based on the first measurement value, the measurement value of the reverse power, and the second measurement value, the first electricity purchase price, the second electricity purchase price, and the virtual electricity selling price.

2. The power management system according to claim 1, wherein the sensor is located on the power system side of the first measuring instrument and the second measuring instrument.

3. The power management system according to claim 1, wherein the sensor includes a first sensor located between the first measuring instrument and the first electrical equipment, and a second sensor located between the second measuring instrument and the second electrical equipment.

4. The power management system according to any one of claims 1 to 3, wherein the second electrical device is a charging system for an electric vehicle, the power management system comprises a charging control device for controlling the charging of the electric vehicle, and the charging control device charges the electric vehicle using surplus power from the distributed power source.

5. The power management system according to claim 4, wherein the charging control device considers the electricity generated by the distributed power source that is discarded to the ground as surplus power.

6. The power management system according to claim 4, wherein the charging control device considers the power that is charged to the battery storage system from the power generated by the distributed power source as the surplus power.

7. The power management system according to claim 4, wherein the distributed power source has multi-string type PV panels, and the charging control device considers the difference in generated power between strings as the surplus power.

8. The power management system according to claim 4, wherein the charging control device charges the electric vehicle using the surplus power when another device controls the supply of X [W] of power from the power system to the consumer, by charging the electric vehicle so that Y [W] of power greater than X is supplied from the power system to the consumer.

9. The power management system can perform a first mode of operation in which the power output from the distributed power source is adjusted so that the reverse power does not flow back into the power grid, as well as a second mode of operation in which the reverse power does flow back into the power grid, and the calculation unit, during operation in the second mode, calculates the electricity charges based on the first measured value, the measured value of the reverse power, and the second measured value, the first electricity purchase price, the second electricity purchase price, and the virtual electricity sales price, in addition to the measured value of the reverse-flowed power and the adjustment price set for the reverse-flowed power, and the adjustment price is the value obtained by subtracting the virtual electricity sales price from the electricity sales price of the reverse-flowed power, as described in any one of claims 1 to 3.

10. The power management system can perform a first mode of operation in which the power output from the distributed power source is adjusted so that the reverse power does not flow back into the power grid, as well as a second mode of operation in which the reverse power does flow back into the power grid, and the calculation unit calculates the electricity charge to the customer based on the first measurement, the second measurement, the measurement of the reverse-flowing power, the first purchase price, the second purchase price, and the purchase price set for the reverse-flowing power, without using the measured value of the reverse power and the virtual electricity selling price, during the operation of the second mode, the power management system according to any one of claims 1 to 3.

11. A power management system according to any one of claims 1 to 3, wherein one of the first measuring instrument and the second measuring instrument communicates with the other measuring instrument to acquire a measurement value of the other measuring instrument over a predetermined period, and transmits the acquired measurement value of the other measuring instrument over the predetermined period and the measurement value of the first measuring instrument over the predetermined period; the first acquisition unit acquires the first measurement value over the predetermined period and the measurement value of the reverse power over the predetermined period transmitted by the first measuring instrument; and the second acquisition unit acquires the second measurement value over the predetermined period transmitted by the first measuring instrument.

12. An auxiliary device different from both the first measuring instrument and the second measuring instrument communicates with each of the first measuring instrument and the second measuring instrument to acquire the first measured value, the measured value of the reverse power, and the second measured value for a predetermined period, and transmits the acquired first measured value, the measured value of the reverse power, and the second measured value for the predetermined period; the first acquisition unit acquires the first measured value and the measured value of the reverse power for the predetermined period transmitted by the auxiliary device; and the second acquisition unit acquires the second measured value for the predetermined period transmitted by the auxiliary device.

13. The power management system according to any one of claims 1 to 3, wherein the first electricity purchase price is constant regardless of the time of day, and the second electricity purchase price and the virtual electricity sales price fluctuate according to the time of day.

14. A power management method to be performed by a power management system installed at a consumer for managing the power of a first electrical device, a second electrical device, and a distributed power source, comprising: a first acquisition step of acquiring a first measured value of the first power supplied from the power system to the first electrical device, measured by a first measuring instrument, and a measured value of the power output from the distributed power source in the opposite direction to the first power; a second acquisition step of acquiring a second measured value of the second power supplied from the power system to the second electrical device, measured by a second measuring instrument different from the first measuring instrument; and a calculation step, wherein the power output from the distributed power source is adjusted so that the reverse power does not flow back into the power system using a sensor for measuring the current between the consumer and the power system; a first electricity purchase price is set for the first power; and a second electricity purchase price different from the first electricity purchase price is set for the second power. A power management method is provided in which, in the calculation step, an electricity charge is calculated for the customer based on the first measured value, the measured value of the reverse power, the second measured value, the first electricity purchase price, the second electricity purchase price, and the virtual electricity selling price.

15. A program for causing the power management system to execute the power management method described in claim 14.

Images