Power management system, charging device, server, and method for regulating power supply and demand balance

Abstract

The present application relates to a power management system, a charging device, a server, and a power supply / demand balance adjustment method. The power management system includes a first server configured to manage a charging device in a microgrid, and a second server configured to manage a power supply / demand balance of a power system. The charging device is configured to perform a charge / discharge operation for suppressing voltage fluctuation of the microgrid by exchanging power between the microgrid and a vehicle, and a reactive power compensation operation for suppressing voltage fluctuation of the power system by controlling reactive power of the microgrid.

Description

Technical Field

[0001] This disclosure relates to power management systems, charging equipment, servers, and methods for regulating power supply and demand balance. Background Technology

[0002] In power systems, it is required that the voltage of the power system be stable and unaffected by load fluctuations. Known devices for suppressing voltage fluctuations include load-time tap-to-change devices (LRTs), step voltage regulators (SVRs), and static var compensators (SVCs). For example, the reactive power compensation device disclosed in Japanese Patent Application Publication No. 2012-16072 has two functions: reactive power compensation to suppress voltage fluctuations in the power system and vehicle charging functionality. Summary of the Invention

[0003] Microgrids are connected to the power system, facilitating the transfer of electricity between the microgrid and the power system. Furthermore, various power regulation resources (generators, natural gas sources, energy storage systems, charging equipment, vehicles, etc.) are internally connected within the microgrid.

[0004] When voltage fluctuations occur in the power system, the power regulation resources within the microgrid can be requested to suppress these fluctuations. On the other hand, even if the power system as a whole maintains a balance between power supply and demand, localized voltage fluctuations may still occur within the microgrid. The inventors of this invention have focused on the challenge of appropriately addressing voltage fluctuations (both power system voltage fluctuations and microgrid voltage fluctuations) that may occur in different ranges.

[0005] This disclosure provides a power management system, charging equipment, server, and a method for regulating power supply and demand balance that appropriately suppresses voltage fluctuations in power systems and microgrids according to conditions.

[0006] The power management system of the first technical solution of this disclosure includes a microgrid. The microgrid is configured to include multiple power regulation resources for power transfer between the microgrid and the power system. The power management system includes: a first server configured to manage the multiple power regulation resources within the microgrid; and a second server configured to manage the power supply and demand balance of the power system. The multiple power regulation resources include charging equipment. The charging equipment is configured to perform: charging and discharging operations to suppress voltage fluctuations in the microgrid by exchanging power between the microgrid and vehicles; and reactive power compensation operations to suppress voltage fluctuations in the power system by controlling the reactive power of the microgrid. The charging equipment is configured to perform charging and discharging operations in response to a request from the first server when the vehicle is electrically connected to the charging equipment; and to perform reactive power compensation operations in response to a request from the second server when the vehicle is not electrically connected to the charging equipment.

[0007] In the first technical solution described above, when the vehicle is electrically connected to the charging device, the charging device performs charging and discharging operations in response to a request from a first server. Conversely, when the vehicle is not electrically connected to the charging device, it performs reactive power compensation operations in response to a request from a second server. That is, the server controlling the charging device is changed depending on whether the vehicle is electrically connected to the charging device. When the vehicle is electrically connected to the charging device, the charging device performs charging and discharging operations via the first server, which can suppress voltage fluctuations in the microgrid. On the other hand, when the vehicle is not electrically connected to the charging device, the charging device performs reactive power compensation operations via the second server, which can suppress voltage fluctuations in the power system. Thus, the charging device can be effectively utilized even when the vehicle is not electrically connected to the charging device, not just when it is. Therefore, according to the first technical solution described above, voltage fluctuations in the power system and voltage fluctuations in the microgrid can be appropriately suppressed depending on the situation.

[0008] In the first technical solution described above, the charging device can also be configured to determine whether a vehicle is electrically connected to the charging device. If the charging device determines that the vehicle is electrically connected, it can also grant control of the charging device to a first server. The first server, having control authority, can also send a request to the charging device when a voltage change occurs in the microgrid.

[0009] In the first technical solution described above, the charging device may also grant control of the charging device to the second server when it determines that the vehicle is not electrically connected to the charging device. Alternatively, the second server, having control authority, may send a request to the charging device when a voltage fluctuation occurs in the microgrid.

[0010] In the first technical solution described above, the first server may also be configured to determine whether the vehicle is electrically connected to the charging equipment. Alternatively, if the first server determines that the vehicle is electrically connected to the charging equipment, it may output a request to the charging equipment when a voltage fluctuation occurs in the microgrid.

[0011] In the first technical solution described above, the first server may grant control of the charging equipment to the second server if it determines that the vehicle is not electrically connected to the charging equipment. Alternatively, the second server, having control authority, may send a request to the charging equipment when a voltage fluctuation occurs in the microgrid.

[0012] In the first technical solution described above, the second server may also be configured to pay the first server a reward corresponding to the number of times or the period during which the charging device performs reactive power compensation actions in response to a request from the second server. The first server may also be configured to receive the reward.

[0013] According to the first technical solution described above, the first server (the operator of the microgrid) can receive payment from the second server for lending charging equipment to the second server (usually a power company). Therefore, the first server can be rewarded for lending charging equipment to the second server.

[0014] The charging device of the second technical solution disclosed herein is electrically connected to a microgrid that transmits and receives power from and from a power system. The charging device includes a processor and a memory storing programs executable by the processor. When a vehicle is electrically connected to the charging device, the processor grants control of the charging device to a first server that manages the power supply and demand balance of the microgrid, and in response to a request from the first server, performs charging and discharging operations between the charging device and the vehicle. Conversely, when the vehicle is not electrically connected to the charging device, the processor grants control to a second server that manages the power supply and demand balance of the power system, and in response to a request from the second server, performs reactive power compensation operations to suppress voltage fluctuations in the power system.

[0015] According to the second technical solution described above, similarly to the first technical solution described above, it is possible to appropriately utilize power regulation resources to suppress voltage fluctuations in the power grid.

[0016] The third technical solution of this disclosure manages the power supply and demand balance of a microgrid that exchanges power with a power system. The server has a processor and a memory storing programs executable by the processor. The microgrid includes charging equipment. The charging equipment is configured to perform: charging and discharging operations to suppress voltage fluctuations in the microgrid by exchanging power between the microgrid and vehicles; and reactive power compensation operations to suppress voltage fluctuations in the power system by controlling the reactive power of the microgrid. The processor is configured to: when the vehicle is electrically connected to the charging equipment, output a request to the charging equipment to perform the charging and discharging operations; and when the vehicle is not electrically connected to the charging equipment, transfer control of the charging equipment to another server capable of outputting a request to the charging equipment to perform reactive power compensation operations.

[0017] According to the third technical solution described above, similarly to the first technical solution described above, voltage fluctuations in the power system and voltage fluctuations in the microgrid can be appropriately suppressed depending on the situation.

[0018] In the third technical solution mentioned above, the server may also be configured to receive compensation from other servers for the number of times or periods during which control authority is transferred to other servers.

[0019] According to the third technical solution described above, similarly to the first technical solution described above, a reward can be given to the first server for lending the charging device to the second server.

[0020] The fourth technical solution of this disclosure discloses a power supply and demand balance regulation method that uses a charging device within a microgrid that transmits and receives power between itself and the power system. In this power supply and demand balance regulation method, when a vehicle is electrically connected to the charging device, control authority over the charging device is granted to a first server managing the power supply and demand balance of the microgrid. The charging device, in response to a request from the first server, performs charging and discharging operations with the vehicle. In the same power supply and demand balance regulation method, when the vehicle is not electrically connected to the charging device, control authority over the charging device is granted to a second server managing the power supply and demand balance of the power system (step S25). The charging device, in response to a request from the second server, performs reactive power compensation operations to suppress voltage fluctuations in the power system.

[0021] According to the fourth technical solution described above, similarly to the first technical solution described above, voltage fluctuations in the power system and voltage fluctuations in the microgrid can be appropriately suppressed depending on the situation.

[0022] According to this technical solution, voltage fluctuations in the power system and the microgrid can be appropriately suppressed depending on the situation. Attached Figure Description

[0023] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals show the same elements, and wherein:

[0024] Figure 1 This is a diagram illustrating the general structure of a power management system according to an embodiment of the present disclosure.

[0025] Figure 2 It is a diagram that shows the structure of the charging equipment and the vehicle in more detail.

[0026] Figure 3 This is a flowchart illustrating the processing steps of a series of processes performed by the charging device in this embodiment.

[0027] Figure 4 This is a flowchart illustrating the processing steps of a series of processes performed by the CEMS server in this embodiment. Detailed Implementation

[0028] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the same or equivalent parts in the drawings are labeled with the same reference numerals, and their description will not be repeated.

[0029] Overall structure of power management system

[0030] Figure 1 This is a diagram illustrating a general structure of the power management system according to an embodiment of the present disclosure. The power management system 100 includes a CEMS 1, a CEMS server 2, power receiving and transforming equipment 3, a power system 4, and a power transmission and distribution operator server 5. CEMS refers to a Community Energy Management System or a City Energy Management System.

[0031] CEMS1 includes a Factory Energy Management System (FEMS) 11, a Building Energy Management System (BEMS) 12, a Home Energy Management System (HEMS) 13, a generator 14, a natural variable power source 15, an Energy Storage System (ESS) 16, Electric Vehicle Supply Equipment (EVSE) 17, and a vehicle 18. Within CEMS1, a microgrid MG is constructed from the above components.

[0032] FEMS11 is a system for managing the supply and demand of electricity used in a factory. FEMS11 includes factory buildings (including lighting fixtures, air conditioning equipment, etc.) and industrial equipment (production lines, etc.) that operate using electricity supplied from the microgrid MG. Although not shown, FEMS11 may include power generation equipment (generators, solar panels, etc.) located in the factory. Sometimes, the electricity generated by the aforementioned power generation equipment is also supplied to the microgrid MG. FEMS11 also includes a FEMS server 110 capable of bidirectional communication with the CEMS server 2.

[0033] BEMS12 is a system for managing the supply and demand of electricity used in buildings such as offices or commercial facilities. BEMS12 includes lighting fixtures and air conditioning equipment installed in the building. BEMS12 can include power generation equipment (solar panels, etc.) or heat and cold source systems (waste heat recovery systems, thermal storage systems, etc.). BEMS12 also includes a BEMS server 120 capable of bidirectional communication with CEMS server 2.

[0034] HEMS13 is a system for managing the supply and demand of electricity used in a home. HEMS13 includes household appliances (lighting equipment, air conditioning units, other electrical products, etc.) that operate using electricity supplied from the microgrid MG. Additionally, HEMS13 may also include solar panels, household heat pump systems, household combined heat and power systems, household batteries, etc. HEMS13 also includes a HEMS server 130 capable of bidirectional communication with CEMS server 2.

[0035] Generator 14 is a power generation device independent of weather conditions, which outputs the generated electricity to the microgrid MG. Generator 14 can include steam turbine generators, gas turbine generators, diesel engine generators, gas engine generators, biomass generators, stationary fuel cells, etc. Generator 14 can also include a combined heat and power system that utilizes the heat generated during power generation.

[0036] The naturally variable power source 15 is a power generation device whose output varies according to weather conditions, and it outputs the generated electricity to the microgrid MG. Figure 1 The example illustrates a solar power generation device (solar panel). The natural variable power source 15 may also include a wind power generation device instead of a solar power generation device, or it may include a wind power generation device in addition to a solar power generation device.

[0037] The energy storage system 16 is a stationary power source that stores electricity generated by the natural variable power source 15, etc. The energy storage system 16 is a secondary battery, such as a lithium-ion battery or a nickel-metal hydride battery (a battery used in vehicles for recycling). However, the energy storage system 16 is not limited to secondary batteries, and may also be a power-to-gas device that uses surplus electricity to produce gaseous fuels (hydrogen, methane, etc.).

[0038] The charging device 17 can be a home-based vehicle charger (EVSE: Electric Vehicle Supply Equipment) or a commercial or public charging station. The charging device 17 is electrically connected to the microgrid MG, enabling it to charge and discharge (supply power) the microgrid MG.

[0039] Specifically, vehicle 18 is a plug-in hybrid vehicle (PHV), electric vehicle (EV), etc. Vehicle 18 is configured to be capable of both external charging and external power supply. That is, when charging cable 19 is connected to the vehicle 18's input port (not shown), vehicle 18 can supply power from the microgrid MG (external charging). Alternatively, vehicle 18 can also be configured to supply power from the vehicle 18 to the microgrid MG when charging cable 19 is connected to the vehicle 18's output port (not shown) (external power supply).

[0040] It should be noted that, in Figure 1 In the example shown, CEMS1 includes one of each of FEMS11, BEMS12, HEMS13, generator 14, natural variable power source 15, and energy storage system 16, but the number of such systems or devices is arbitrary. CEMS1 may also include multiple of the above-mentioned systems or devices, and may also include systems or devices not included in CEMS1. FEMS11 (factory buildings, industrial equipment, etc.), BEMS12 (lighting fixtures, air conditioning equipment, etc.), HEMS13 (household appliances, etc.), generator 14, natural variable power source 15, energy storage system 16, charging equipment 17, and vehicle 18 included in CEMS1 are each examples of the "electricity regulation resources" of this disclosure, and therefore, without specifically distinguishing the above-mentioned systems or devices, they are also referred to as "electricity regulation resources" below.

[0041] CEMS Server 2 is a computer that manages the power regulation resources within CEMS1. CEMS Server 2 includes a control unit 201, a storage unit 202, and a communication unit 203. The control unit 201 includes a processor configured to perform predetermined computational processing. The storage unit 202 includes a memory storing programs executed by the control unit 201, and stores various information (mappings, formulas, parameters, etc.) used by these programs. Additionally, the storage unit 202 includes a database storing data related to the power of the systems or equipment contained in CEMS1 (power generation history, power consumption history, etc.). The communication unit 203 includes a communication interface configured to communicate with external devices (other servers, etc.).

[0042] CEMS server 2 can also be an integrator server. An integrator is an electrical operator that aggregates multiple power regulation resources to provide energy management services. CEMS server 2 is an example of the "first server" or "server" disclosed herein. Alternatively, the servers (110, 120, 130) included in each system of FEMS11, BEMS12, and HEMS13 can also be considered as examples of the "first server" or "server" disclosed herein.

[0043] The power receiving device 3 is located at the connection point (power receiving point) of the microgrid MG, configured to switch the parallel (connection) / disconnection (shutdown) between the microgrid MG and the power system 4. While not shown in the figures, the power receiving device 3 includes a high-voltage side (primary side) switching device, a transformer, a protective relay, measuring equipment, and a control device. When the microgrid MG is connected to the power system 4, the power receiving device 3 receives AC power from the power system 4, for example, ultra-high voltage (voltage exceeding 7000V), and steps down the received power to supply it to the microgrid MG.

[0044] Power system 4 is a power grid constructed using power plants and transmission and distribution equipment. In the above implementation, the power company acts as both a power generation operator and a transmission and distribution operator. The power company is an example of a typical transmission and distribution operator, and also an example of the manager of power system 4, maintaining and managing power system 4.

[0045] The power transmission and distribution operator server 5 is a computer belonging to the power transmission and distribution operator (power company) and managing the power supply and demand of power system 4. The power transmission and distribution operator server 5 is also configured to enable bidirectional communication with CEMS server 2. It should be noted that the power transmission and distribution operator server 5 is an example of a "second server" or "other server" in this disclosure.

[0046] Structure of charging equipment and vehicles

[0047] Figure 2This is a diagram showing the structure of the charging device 17 and the vehicle 18 in more detail. The charging device 17 is connected to the power distribution system of the microgrid MG. The charging device 17 includes a voltage measuring unit 71, a current measuring unit 72, a power conversion device 73, and a controller 74.

[0048] The voltage measuring unit 71 measures the AC voltage (system voltage) at the connection point between the charging device 17 and the power distribution system. The current measuring unit 72 measures the AC current (system current) at the connection point between the charging device 17 and the power distribution system. The measured system voltage and system current are output to the controller 74.

[0049] The power conversion device 73 is configured to generate active power or reactive power using power supplied from the microgrid MG according to power command values ​​from the controller 74. More specifically, the power conversion device 73 includes an inverter 731 and a large-capacity capacitor 732. The inverter 731 includes multiple switching elements capable of PWM (Pulse Width Modulation) control of three-phase AC (U-phase, V-phase, W-phase). The capacitor 732 is electrically connected to the DC output side of the inverter 731. The power conversion device 73 may also include a DC / DC converter in addition to the inverter 731. For details regarding the structure and operation of the power conversion device 73, please refer to, for example, Japanese Patent Application Publication No. 2012-16072.

[0050] The controller 74 generates power command values ​​(effective power command value and reactive power command value) for the power conversion device 73 based on the voltage and current of the microgrid MG measured by the voltage measuring unit 71 and the current measuring unit 72.

[0051] The controller 74 includes a processor 741 (such as a CPU, Central Processing Unit), a memory 742 (such as ROM, Read Only Memory, and RAM), input / output (I / O) circuitry (not shown), and a communication unit 743. The processor 741, memory 742, I / O circuitry, and communication unit 743 can send and receive data via a bus. A program is pre-stored in a portion of the memory 742, and the processor 741 executes this program to control the power conversion device 73 (described later).

[0052] The vehicle 18 includes an access point 81, a battery 82, and an ECU (Electronic Control Unit) 83.

[0053] The input port 81 is configured to allow insertion of a charging plug 191 located at the tip of the charging cable 19 via a mechanical connection such as a mating mechanism. The user (driver of vehicle 18 or operator of a charging station, etc.) inserts the charging plug 191 into the input port 81, thereby connecting the charging device 17 and the vehicle 18 via the charging cable 19. This ensures an electrical connection for power transmission between the charging device 17 and the vehicle 18, and enables the mutual transmission and reception of various signals (commands, data, etc.).

[0054] Battery 82 is a battery pack comprising multiple battery cells. Each battery cell is a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. Battery 82 supplies electricity to generate the driving force for vehicle 18. In addition, battery 82 stores electricity generated by an onboard electric generator (not shown). It should be noted that capacitors such as double-layer capacitors can also be used instead of battery 82.

[0055] Like the controller 74 of the charging device 17, the ECU 83 includes a processor 831, a memory 832, I / O circuitry (not shown), and a communication unit 833. The processor 831 is configured to perform various controls on the vehicle 18, and in this embodiment, in particular, performs various computational processes related to external charging control. The memory 832 stores various information (maps, formulas, parameters, etc.) used in the programs executed by the processor 831. The communication unit 833 is configured to communicate with external devices (controller 74 and CEMS server 2).

[0056] In the charging device 17 and vehicle 18 configured as described above, the controller 74 of the charging device 17 is configured to perform a "charge and discharge operation" that charges or discharges the vehicle 18 (battery 82) with the microgrid MG. By charging the vehicle 18 with power from the microgrid MG or discharging the vehicle 18 with power from the microgrid MG, the controller 74 can suppress voltage fluctuations in the microgrid MG.

[0057] Furthermore, the controller 74 is configured to perform a "reactive power compensation operation," which compensates for the reactive power of the microgrid MG by rapidly and steplessly generating reactive power from leading to lagging. The controller 74 outputs leading reactive power from the charging device 17 when a voltage rise in the microgrid MG is required, and outputs lagging reactive power from the charging device 17 when a voltage drop in the microgrid MG is required. Thus, by maintaining a constant voltage in the microgrid MG, voltage fluctuations in the power system 4 electrically connected to the microgrid MG can be suppressed. For details regarding the reactive power compensation operation, please refer to Japanese Patent Application Publication No. 2012-16072.

[0058] In this embodiment, a structure is adopted that switches the control authority of the charging device 17 based on whether the vehicle 18 is connected to the charging device 17. More specifically, when the vehicle 18 is connected to the charging device 17, the CEMS server 2 maintains control authority over the charging device 17 as is normally the case. In this case, the CEMS server 2 causes the charging device 17 connected to the vehicle 18 to perform charging and discharging operations.

[0059] On the other hand, when vehicle 18 is not connected to charging equipment 17, control of charging equipment 17 is transferred from CEMS server 2 to power transmission and distribution operator server 5. In other words, when vehicle 18 is not connected to charging equipment 17, charging equipment 17 is lent to the power company, which is the manager of power transmission and distribution operator server 5. Power transmission and distribution operator server 5 causes charging equipment 17 to perform reactive power compensation. Thus, charging equipment 17, which is not connected to vehicle 18, can be effectively used to suppress voltage fluctuations in power system 4. Moreover, the manager of CEMS server 2 (the operating entity of CEMS1) can also receive payment from the power company for lending charging equipment 17 to the power company.

[0060] Processing flow

[0061] Figure 3 This is a flowchart illustrating the processing steps of a series of processes performed by the charging device 17 in this embodiment. Figure 3 and the following Figure 4 In the flowchart, the left side represents the processing performed by CEMS server 2, the center represents the processing performed by charging device 17 (controller 74), and the right side represents the processing performed by power distribution operator server 5. The flowchart above is, for example, called and executed from a main routine (not shown) at predetermined intervals. Each step is implemented through software processing by a processor, but can also be implemented through hardware processing based on LSI (Large Scale Integration), etc. Hereinafter, the steps will be abbreviated as "S".

[0062] In step S21, the charging device 17 determines whether the vehicle 18 has been connected to the charging device 17 via the charging cable 19. It should be noted that, here, we are assuming that the vehicle 18 is not in a situation where its departure time is approaching and it is required to charge the vehicle 18 immediately, but rather that there is a certain amount of time leeway before the time to start charging according to the charging schedule, and the vehicle 18 is in a state where it can both charge and discharge.

[0063] If vehicle 18 is connected to charging device 17 ("Yes" in step S21), charging device 17 grants control of itself to CEMS server 2 (step S22). Conversely, if vehicle 18 is not connected to charging device 17 ("No" in step S21), charging device 17 grants control of itself to power distribution operator server 5 (step S25).

[0064] After the CEMS server 2 accepts control of the charging device 17, in step S11, the CEMS server 2 determines whether the microgrid MG has generated excess power or insufficient power, resulting in voltage fluctuations in the microgrid MG (whether it is a situation where voltage fluctuations in the microgrid MG may occur). If voltage fluctuations in the microgrid MG occur (yes in step S11), the CEMS server 2 outputs a power regulation request to the charging device 17 to suppress voltage fluctuations in the microgrid MG, more specifically, a charging request to store excess power or a discharging request to supplement insufficient power (step S12). If no voltage fluctuations occur in the microgrid MG (no in step S11), the processing in step S12 is skipped.

[0065] In step S23, the charging device 17 determines whether it has received a power adjustment request from the CEMS server 2. If a power adjustment request is received (yes in step S23), the charging device 17 initiates the process to step S24, and in response to the power adjustment request, charges or discharges the vehicle 18 (charge / discharge operation). That is, if the charging device 17 receives a charging request to store remaining power, it charges the vehicle 18; if it receives a discharging request to replenish insufficient power, it discharges the vehicle 18. This suppresses voltage fluctuations in the microgrid MG. Afterward, the charging device 17 returns the process to the main routine. If no power adjustment request is received (no in step S23), the process in step S24 is skipped.

[0066] On the other hand, after the power distribution operator server 5 accepts control of the charging device 17, in step S31, the power distribution operator server 5 determines whether a voltage fluctuation in the power system 4 has occurred (whether it is a situation where a voltage fluctuation in the power system 4 may occur). If a voltage fluctuation in the power system 4 occurs ("Yes" in step S31), the power distribution operator server 5 outputs a power regulation request to the charging device 17 to suppress the voltage fluctuation in the power system 4, more specifically, a request for reactive power compensation (step S32). If no voltage fluctuation in the power system 4 occurs ("No" in step S11), the processing in step S32 is skipped.

[0067] In step S26, the charging device 17 determines whether it has received a power regulation request from the power distribution operator server 5. If a power regulation request has been received (yes in step S26), the charging device 17 responds to the request by performing reactive power compensation and outputting reactive power to the microgrid MG (step S27). This suppresses voltage fluctuations in the power system 4. Afterward, the charging device 17 returns the process to the main routine. If no power regulation request has been received (no in step S26), step S27 is skipped.

[0068] exist Figure 3 In the example, the structure for managing the restricted permissions of the charging device 17 itself is described. However, the method for managing the restricted permissions of the charging device 17 is not limited to this. For example, as described below, the restricted permissions (also known as command authority) of the charging device 17 can also be managed by the CEMS server 2.

[0069] Figure 4 This is a flowchart illustrating the series of processing steps performed by the CEMS server 2 in this embodiment. In step S41, the CEMS server 2 determines whether the vehicle 18 is connected to the charging device 17. The CEMS server 2 can obtain whether the vehicle 18 is connected to the charging device 17 by communicating with the charging device 17.

[0070] If vehicle 18 is connected to charging device 17 (yes in step S41), CEMS server 2 maintains the access control of charging device 17. CEMS server 2 determines whether voltage fluctuation has occurred in microgrid MG due to excess power or insufficient power (step S42). If voltage fluctuation has occurred in microgrid MG (yes in step S42), CEMS server 2 outputs a power regulation request to charging device 17 to suppress voltage fluctuation in microgrid MG, more specifically, a charging request to store excess power or a discharging request to replenish insufficient power (step S43). If no voltage fluctuation has occurred in microgrid MG (no in step S42), step S43 is skipped.

[0071] In contrast, if vehicle 18 is not connected to charging device 17 (No in step S41), CEMS server 2 transfers control of charging device 17 to power distribution operator server 5. After receiving control of charging device 17 from CEMS server 2 (Yes in step S61), power distribution operator server 5 determines whether a voltage fluctuation has occurred in power system 4 (step S62). If a voltage fluctuation has occurred in power system 4 (Yes in step S62), power distribution operator server 5 outputs a power regulation request (reactive power compensation request) to charging device 17 to suppress the voltage fluctuation in power system 4 (step S63). If no voltage fluctuation has occurred in power system 4 (No in step S62), step S63 is skipped.

[0072] In step S51, the charging device 17 determines whether the power regulation request originates from the CEMS server 2. If the power regulation request originates from the CEMS server 2 ("Yes" in step S51), the charging device 17 responds to the power regulation request by charging or discharging the vehicle 18 (step S52). On the other hand, if the power regulation request does not originate from the CEMS server 2 ("No" in step S51), that is, if the power regulation request originates from the power distribution operator server 5, the charging device 17 responds to the power regulation request by performing reactive power compensation and outputting reactive power to the microgrid MG (step S53). Afterward, the charging device 17 returns the processing to the main routine.

[0073] As described above, in this embodiment, control of the charging device 17 is exchanged between the CEMS server 2 and the power distribution operator server 5 depending on whether the vehicle 18 is connected to the charging device 17. When the vehicle 18 is not connected to the charging device 17, the CEMS server 2 (the operating entity of CEMS 1) places the charging device 17 in place of the unused device and lends it to the power distribution operator server 5 (the power company managing the power distribution operator server 5). By enabling the charging device 17, which cannot perform charging and discharging operations because it is not connected to the vehicle 18, to perform reactive power compensation operations, voltage fluctuations in the power system 4 can be effectively suppressed using the charging device 17. Therefore, according to this embodiment, the charging device 17, as a power regulation resource, can be appropriately utilized to suppress voltage fluctuations in the microgrid MG and the power system 4.

[0074] Furthermore, the CEMS server 2 can collect payment from the power distribution operator server 5 for lending the charging equipment 17. The payment can be an amount corresponding to the number of times or the duration of reactive power compensation operations actually performed by the charging equipment 17. Alternatively, the payment can be an amount corresponding to the number of times or the duration of the transfer of control authority from the CEMS server 2 to the power distribution operator server 5. However, the method for determining the payment is not limited to these methods. The payment can also be an amount determined in predetermined period units (fixed-rate system).

[0075] It should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of this disclosure is not defined by the description of the above embodiments, but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power management system, characterized in that, include: Power system; A microgrid is configured to include multiple power regulation resources that transmit and receive power between the microgrid and the power system. The first server is a server belonging to an integrator that aggregates the multiple power regulation resources to provide energy management services, and is configured to manage the multiple power regulation resources within the microgrid, including vehicle charging equipment; as well as The second server, belonging to the operator of the power system, is configured to manage the power supply and demand balance of the power system and is capable of communicating with the first server and the charging equipment. The charging device is configured to switch the target of granting control authority to the charging device based on whether the vehicle is electrically connected to the charging device, and to determine whether a power adjustment request has been received. The charging device is configured such that, upon determining that the vehicle is electrically connected to the charging device, control of the charging device is granted to the first server; and, upon determining that a first power regulation request has been received from the first server, charging and discharging operations are performed to suppress voltage fluctuations in the microgrid by exchanging power between the microgrid and the vehicle. The charging device is configured such that, if it is determined that the vehicle is not electrically connected to the charging device, the control authority of the charging device is granted to the second server, and if it is determined that a second power regulation request is received from the second server, a reactive power compensation action is performed to suppress voltage fluctuations in the power system by controlling the reactive power of the microgrid.

2. The power management system according to claim 1, characterized in that, When the first server has the control authority, it outputs the first power regulation request to the charging device when the voltage of the microgrid changes.

3. The power management system according to claim 2, characterized in that, When the second server has the control authority, it outputs the second power regulation request to the charging device when the power system voltage changes.

4. The power management system according to any one of claims 1 to 3, characterized in that, The second server is configured to pay the first server a reward corresponding to the number of times or the period during which the charging device performs the reactive power compensation action in response to the second power adjustment request from the second server. The first server is configured to receive the reward.

5. A power management system, characterized in that, include: Power system; A microgrid is configured to include multiple power regulation resources that transmit and receive power between the microgrid and the power system. The first server is a server belonging to an integrator that aggregates the multiple power regulation resources to provide energy management services, and is configured to manage the multiple power regulation resources within the microgrid, including vehicle charging equipment; as well as The second server, belonging to the operator of the power system, is configured to manage the power supply and demand balance of the power system and is capable of communicating with the first server and the charging equipment. The charging device is configured to switch the target of granting control authority to the charging device based on whether the vehicle is electrically connected to the charging device, and to determine whether a power adjustment request has been received. The first server is configured to determine whether the vehicle is electrically connected to the charging equipment. If the vehicle is determined to be electrically connected to the charging equipment, it outputs a first power regulation request to the charging equipment when a voltage fluctuation occurs in the microgrid. If the vehicle is determined not to be electrically connected to the charging equipment, it grants control of the charging equipment to the second server. When the second server has the aforementioned control authority, it outputs a second power regulation request to the charging device when a voltage fluctuation occurs in the power system. The charging device is configured to, upon determining that a first power regulation request has been received from the first server, perform a charging and discharging operation that suppresses voltage fluctuations in the microgrid by exchanging power between the microgrid and the vehicle. The charging device is configured to perform reactive power compensation by controlling the reactive power of the microgrid to suppress voltage fluctuations in the power system when it is determined that a second power regulation request has been received from the second server.

6. The power management system according to claim 5, characterized in that, The second server is configured to pay the first server a reward corresponding to the number of times or the period during which the charging device performs the reactive power compensation action in response to the second power adjustment request from the second server. The first server is configured to receive the reward.

7. A charging device electrically connected to a microgrid for power transmission and reception between the microgrid and a power system, the charging device being characterized in that it comprises: processor; as well as The memory stores programs that can be executed by the processor. Wherein, the processor The control authority of the charging equipment is switched based on whether the vehicle is electrically connected to the charging equipment, and it is determined whether a power adjustment request has been received. When the vehicle is electrically connected to the charging device, control of the charging device is granted to a first server that manages the power supply and demand balance of the microgrid. In response to a first power regulation request from the first server, a charging and discharging operation is performed to suppress voltage fluctuations in the microgrid by exchanging power with the vehicle. The first server is configured to manage multiple power regulation resources within the microgrid and is a server belonging to an integrator that aggregates the multiple power regulation resources to provide energy management services. The multiple power regulation resources include the charging device. On the other hand, when the vehicle is not electrically connected to the charging equipment, the control authority is granted to a second server that manages the power supply and demand balance of the power system. In response to a second power regulation request from the second server, reactive power compensation is performed to suppress voltage fluctuations in the power system by controlling the reactive power of the microgrid. The second server is a server belonging to the operator of the power system and is able to communicate with the first server and the charging equipment.

8. A method for regulating power supply and demand balance, using charging equipment within a microgrid that transmits and receives power between itself and a power system, the method being characterized by comprising: The control authority of the charging equipment is switched based on whether the vehicle is electrically connected to the charging equipment, and it is determined whether a power adjustment request has been received. With the vehicle electrically connected to the charging device, control of the charging device is granted to a first server managing the power supply and demand balance of the microgrid. In response to a first power regulation request from the first server, the charging device performs charging and discharging operations with the vehicle to suppress voltage fluctuations in the microgrid by exchanging power between the microgrid and the vehicle. The first server is a server belonging to an integrator that aggregates multiple power regulation resources to provide energy management services, including the charging device. When the vehicle is not electrically connected to the charging device, the control authority of the charging device is granted to a second server that manages the power supply and demand balance of the power system. In response to a second power regulation request from the second server, the charging device performs reactive power compensation by controlling the reactive power of the microgrid to suppress voltage fluctuations in the power system. The second server is a server belonging to the operator of the power system and is able to communicate with the first server and the charging device.

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