Charging and discharging system

Abstract

Considering the vehicle's power consumption, relay operation count, and operating mode, power from inside the vehicle is supplied to the outside. [Solution] If it is determined that the number of operations exceeds the relay lifespan of the charge / discharge relay, the system continues in standby mode without outputting a stop request to the outside. If it is determined that the amount of external charge per unit time falls below the vehicle's power consumption, it outputs a stop request to the outside. If a command for charge amount monitoring mode is received from the outside, the system monitors the amount of external charge.

Description

[Technical Field]

[0001] The present disclosure relates to a charge-discharge system. [Background Art]

[0002] As described in the following Patent Document 1, there is known a vehicle capable of supplying electric power from inside the vehicle to the outside of the vehicle. Supplying electric power from inside the vehicle to the outside of the vehicle is also referred to as V2H (Vehicle to Home). [Prior Art Literature] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2022-116971 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Since vehicle power consumption during V2H is large, in the conventional technology, the energy balance of the vehicle may become negative, for example, when the amount of solar radiation is low and the surplus PV power is small. If V2H is frequently stopped to suppress power consumption, the number of relay operations on the vehicle side increases, and there is a risk that the relay will reach the end of its service life. On the other hand, in the event of a power outage, high responsiveness is prioritized, and even if the V2H charge amount is lower than the vehicle power consumption amount, it is desired that the vehicle continue to stand by without stopping, but the vehicle cannot determine a power outage.

[0005] As described above, conventional V2H stop determination does not take into account vehicle power consumption and the number of relay operations, nor does it take into account external requirements (operation modes) such as those during power outages.

[0006] An object of the present disclosure is to provide a charge-discharge system that supplies electric power from inside a vehicle to the outside of the vehicle, in consideration of vehicle power consumption, the number of relay operations, and the operation mode. [Means for Solving the Problem]

[0007] This disclosure relates to a charging and discharging system comprising: a power supply device capable of supplying power from a power source inside a vehicle to the outside; a relay connected between the power source and the power supply device; and a control device that controls the power supply device and the relay. The control device continues in standby mode without outputting a stop request to the outside when it determines that the number of operations has exceeded the relay lifespan of the relay; outputs a stop request to the outside when it determines that the amount of external charge per unit time has fallen below the vehicle's power consumption; and monitors the amount of external charge when it receives a command for charge amount monitoring mode from the outside. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a charging and discharging system that supplies power from inside the vehicle to the outside, taking into account vehicle power consumption, relay operation count, and operating mode. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows an example of the configuration of a house and a vehicle that constitute the power system in this embodiment. [Figure 2] Figure 2 is a flowchart illustrating the operation of the ECU shown in Figure 1. [Figure 3] Figure 3 is a flowchart illustrating the relay life calculation shown in Figure 2. [Figure 4] Figure 4 is a flowchart illustrating the operation mode monitoring shown in Figure 2. [Figure 5] Figure 5 is a flowchart illustrating the charge level monitoring shown in Figure 2. [Modes for carrying out the invention]

[0010] This embodiment will now be described with reference to the attached drawings. To facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing whenever possible, and redundant explanations are omitted.

[0011] Figure 1 shows an example configuration of a house 10 and a vehicle 20 used in a power system. The power system includes, for example, a house 10, a vehicle 20, a connecting cable 15, a connecting connector 17, a power grid 30, and a transmission line (not shown).

[0012] House 10 is connected to a power transmission line and can exchange power with the power grid 30 via the transmission line. House 10 can also exchange power with a vehicle 20 connected to it via a connecting cable 15 and a connecting connector 17.

[0013] Vehicle 20 is an electric vehicle equipped with a power storage device as a DC power source, such as an electric car. Vehicle 20 is electrically connected to the house 10 by a connecting cable 15 and a connecting connector 17. Vehicle 20 can generate power equivalent to commercial power and supply it to the house 10, and can also charge its power storage device by receiving power from the house 10. In other words, vehicle 20 can be used as a power source for the house 10. Alternatively, the house 10 can supply power to the power grid 30 using vehicle 20 as a power source.

[0014] The connecting cable 15 is a power line for electrically connecting the vehicle 20 to the house 10. The connecting connector 17 is a connector for electrically connecting the connecting cable 15 to the vehicle 20.

[0015] The power grid 30 is a commercial power system composed of numerous power generation facilities that generate grid power. Various power generation facilities, such as thermal power plants, nuclear power plants, wind power plants, hydroelectric power plants, and solar power plants, are connected to the power grid 30, as well as other buildings such as houses and factories. In these buildings, if vehicles equipped with energy storage devices are connected, power can be supplied to the power grid 30 using the energy storage devices as a power source.

[0016] A further description will be given of the vehicle 20. The vehicle 20 includes a system main relay 21, a power control unit (PCU: Power Control Unit) 22, a power storage device 29, a motor generator (MG: Motor Generator) 61, a power transmission gear 65, driving wheels 66, and an ECU (Electronic Control Unit) 100.

[0017] The SMR 21 is a relay circuit electrically connected between the power storage device 29 and the PCU 22. The closing / opening of the SMR 21 is controlled in accordance with a command from the ECU 100.

[0018] The PCU 22 performs power conversion between the power storage device 29 and the MG 61 in accordance with a command from the ECU 100. The PCU 22 includes an inverter that receives power from the power storage device 29 to drive the MG 61, a converter that adjusts the level of a DC voltage supplied to the inverter (neither of which is shown), and the like.

[0019] The power storage device 29 is a rechargeable DC power supply, and is configured including a secondary battery such as, for example, a nickel-metal hydride battery or a lithium-ion battery having a liquid or solid electrolyte. A capacitor such as an electric double layer capacitor can also be used as the power storage device 29. The power storage device 29 supplies power for generating traveling driving force of the vehicle 20 to the PCU 22. Further, the power storage device 29 is charged by power generated by regenerative braking of the MG 61, discharged by the driving operation of the MG 61, charged by power supplied from outside the vehicle, or discharged by supplying power to the outside of the vehicle.

[0020] The MG 61 is a three-phase AC rotating electric machine, for example, a permanent magnet type synchronous motor including a rotor in which permanent magnets are embedded. The MG 61 has a function as an electric motor (motor) and a function as an electric generator (generator). The MG 61 is connected to the power storage device 29 via the PCU 22.

[0021] MG61 is driven, for example, by an inverter included in PCU 22 when the vehicle 20 is traveling. The power of MG61 is transmitted to drive wheels 66 via a power transmission gear 65 formed of a differential gear or the like. Further, for example, when the vehicle 20 is being braked, MG61 is driven by the drive wheels 66, MG61 operates as a generator to perform regenerative braking. The electric power generated by MG61 is stored in the power storage device 29 via PCU 22.

[0022] The vehicle 20 further includes a charging / discharging relay 26, a power converter 27, and an inlet 28 as a configuration for performing external charging or external power feeding. A connection connector 17 of the house 10 is connected to the inlet 28. The connection connector 17 is connected to a HEMS (Home Energy Management System) 11 of the house 10 via a connection cable 15. Although FIG. 1 shows a state where the connection connector 17 is attached to the inlet 28, the connection connector 17 is configured to be detachable from the inlet 28, the connection connector 17 is attached to the inlet 28 when external charging or external power feeding is performed, and the connection connector 17 is removed from the inlet 28 when the vehicle 20 is driven.

[0023] During external charging of the power storage device 29, electric power is supplied from the HEMS 11 side to the power converter 27 via the connection cable 15, the connection connector 17 and the inlet 28. The supplied electric power is converted by the power converter 27 into electric power with which the power storage device 29 can be charged (hereinafter referred to as charging electric power), and the converted charging electric power is supplied to the power storage device 29.

[0024] On the other hand, during external power feeding from the power storage device 29, the electric power is converted into predetermined electric power (for example, alternating-current electric power) by the power converter 27, and the converted alternating-current electric power is supplied to the HEMS 11 via the inlet 28, the connection connector 17 and the connection cable 15.

[0025] The charge / discharge relay 26 is a relay circuit electrically connected between the energy storage device 29 and the power converter 27. When the charge / discharge relay 26 is closed and the SMR 21 is closed, power transmission becomes possible between the inlet 28 and the energy storage device 29.

[0026] The power converter 27 is electrically connected between the charge / discharge relay 26 and the inlet 28. The power converter 27 converts the power supplied from the HEMS 11 into charging power, or converts the power from the energy storage device 29 into power that can be supplied (for example, AC 100V alternating current power), according to commands from the ECU 100. The charge / discharge system in this embodiment includes the HEMS 11, the connection cable 15, the connection connector 17, the SMR 21, the charge / discharge relay 26, the power converter 27, and the inlet 28.

[0027] The ECU 100 consists of a CPU 101, a memory 102, and input / output ports (not shown) for inputting and outputting various signals. The ECU 100 controls various devices within the vehicle 20 (SMR 21, PCU 22, charge / discharge relay 26, power converter 27, etc.) so that the vehicle 20 reaches a desired state. The various controls performed by the ECU 100 are software-based, meaning they are executed by the CPU 101 reading a program stored in the memory 102. The various controls performed by the ECU 100 are not limited to software-based processing and may also be processed by dedicated hardware (electronic circuits).

[0028] The ECU100 is connected to a battery temperature sensor 110, a battery current sensor 112, and a battery voltage sensor 114.

[0029] The battery temperature sensor 110 detects the temperature TB at a predetermined location in the energy storage device 29 (for example, the location of the energy storage device 29 that is the hottest) and transmits a signal indicating the detected temperature TB to the ECU 100. The battery current sensor 112 detects the current IB flowing through the energy storage device 29 and transmits a signal indicating the detected current IB to the ECU 100. The battery voltage sensor 114 detects the voltage VB between the terminals of the energy storage device 29 and transmits a signal indicating the detected voltage VB to the ECU 100.

[0030] Vehicle 20 further includes a wireless communication device 50 and a display device 53. The wireless communication device 50 is configured to communicate various information with the outside of the vehicle. The wireless communication device 50 includes a long-range communication module 51 and a short-range communication module 52. The long-range communication module 51 includes, for example, an LTE (Long Term Evolution) communication module. The long-range communication module 51 is configured to enable bidirectional data communication with a base station (not shown) in the communication network 6. The short-range communication module 52 is configured to enable bidirectional data communication between the vehicle 20 and the vehicle 20's user's mobile terminal 300 or home 10 located at a short distance (for example, several meters to several tens of meters). The vehicle 20 may be configured to enable data communication with the home 10 via the long-range communication module 51 and the communication network 6, or it may be configured to enable direct data communication via the short-range communication module 52.

[0031] Furthermore, the ECU 100 transmits various information (such as the location information of the vehicle 20) to the house 10 via the wireless communication device 50, and receives information from the house 10.

[0032] The display device 53 is installed in a position visible to the driver while driving the vehicle 20 (for example, on the instrument panel). The display device 53 is composed of, for example, a liquid crystal display or an organic EL (Electro-Luminescence) display. The display device 53 displays text information, images, etc., in response to control signals from the ECU 100.

[0033] The ECU 100 calculates the State of Charge (SOC) of the energy storage device 29, for example, when the vehicle 20 is in operation, or when the vehicle 20 is parked and the connection connector 17 is connected to the inlet 28, allowing power to be exchanged between the house 10 and the energy storage device 29.

[0034] Various known methods can be used to calculate the State of Charge (SOC), such as methods using current value integration (Coulomb count) or methods using open-circuit voltage (OCV) estimation.

[0035] The house 10 includes a HEMS 11, a communication device 12, a solar power generation device 13, a display device 14, and electrical equipment 18.

[0036] HEMS11 is composed of, for example, a distribution board, a power converter, and a control device. The HEMS11 is electrically connected to a solar power generation device 13, electrical equipment 18, a vehicle 20, and a power grid 30. The HEMS11 is provided with an input / output unit 11a for exchanging power with the vehicle 20, an input / output unit 11b for exchanging power with the power grid 30, an output unit 11c for supplying power to the electrical equipment 18, and a relay 11f that is electrically connected between the solar power generation device 13 and the power grid 30 and the input / output unit 11a.

[0037] Furthermore, the HEMS 11 includes a CPU 11d and a memory 11e. The HEMS 11 controls each device within the HEMS 11 so that the power exchange state with each connected device is in a desired state. Various controls performed by the HEMS 11 are software processes, that is, programs stored in the memory 11e are read by the CPU 11d and executed. Various controls by the HEMS 11 are not limited to software processes, but may also be processed by dedicated hardware (electronic circuits).

[0038] HEMS11 adjusts, for example, the amount of electricity supplied from the power grid 30 or the solar power generation device 13 to the electrical equipment 18 or the vehicle 20. Alternatively, HEMS11 adjusts, for example, the amount of electricity supplied from the vehicle 20 to the electrical equipment 18 or the power grid 30.

[0039] The communication device 12 is configured to communicate with the wireless communication device 50 of the vehicle 20 either by predetermined wireless communication or by communication via the communication network 6.

[0040] The solar power generation device 13 is a power generation device that generates electricity by converting the light energy of sunlight into electrical energy. The solar power generation device 13 supplies the generated electricity to the HEMS 11.

[0041] The display device 14 is installed in a location visible to the user within the house 10. The display device 14 is composed of, for example, a liquid crystal display or an organic EL display. The display device 14 displays text information, images, etc., in response to control signals from the HEMS 11. The electrical equipment 18 includes home appliances and other equipment installed within the house 10.

[0042] When the connection connector 17 is connected to the inlet 28 of the vehicle 20, the HEMS 11 supplies power from the energy storage device 29 to the electrical equipment 18 in the house 10, or supplies power generated by the solar power generation device 13 or power from the power grid 30 to the vehicle 20. In the following description, this operation of exchanging power between the house 10 and the vehicle 20 will be referred to as "V2H operation". For example, the HEMS 11 may perform V2H operation when the connection connector 17 is connected to the inlet 28 of the vehicle 20, or it may perform V2H operation when it receives a request signal to perform V2H operation from at least one of the house 10, the vehicle 20, the management server 200, and the mobile terminal 300 while the connection connector 17 is connected to the inlet 28.

[0043] The management server 200 is configured to communicate with the house 10, the vehicle 20, and the mobile terminal 300 via the communication network 6. The management server 200 receives various information from each of the house 10, the vehicle 20, and the mobile terminal 300 via the communication network 6, and transmits various information to each of the house 10, the vehicle 20, and the mobile terminal 300 via the communication network 6.

[0044] The mobile terminal 300 is a user-portable terminal that includes, for example, a display device, an input device, and a communication device (none of which are shown). The communication device of the mobile terminal 300 is configured to communicate with the house 10, the vehicle 20, and the management server 200 via the communication network 6.

[0045] For example, the management server 200 receives a predetermined signal from the vehicle 20 and sends a display request signal to the mobile terminal 300 to display a signal corresponding to the received predetermined signal, or it receives a signal indicating the input result to the input device of the mobile terminal 300 and sends a control request signal to the vehicle 20 to perform control corresponding to the signal indicating the received input result.

[0046] Next, an example of the operation of the ECU 100 will be explained with reference to Figure 2. In step S01, the connection connector 17 is connected to the inlet 28 of the vehicle 20. In step S02, which follows step S01, V2H operation is started.

[0047] In step S03, following step S02, the ECU 100 calculates the lifespan of the charge / discharge relay 26. The lifespan of the charge / discharge relay 26 is calculated as the number of lifespan operations N' of the charge / discharge relay 26. The process in step S03 will be described in detail later.

[0048] In step S04, following step S03, the ECU 100 determines whether the number of operations N of the charge / discharge relay 26 is less than the lifespan of the charge / discharge relay 26's operation count N'. If the number of operations N of the charge / discharge relay 26 is less than the lifespan of the charge / discharge relay 26's operation count N' (step S04: YES), the process proceeds to step S05. If the number of operations N of the charge / discharge relay 26 is not less than the lifespan of the charge / discharge relay 26's operation count N' (step S04: NO), the process transitions to standby mode.

[0049] In step S05, the ECU100 monitors the operating mode M. The operating mode M is determined to be either the charge level monitoring mode or another mode. The processing in step S05 will be described in detail later.

[0050] In step S06, following step S05, the ECU 100 determines whether the operating mode M is the charge monitoring mode. If the operating mode M is the charge monitoring mode (step S06: YES), the process proceeds to step S07. If the operating mode M is not the charge monitoring mode (step S06: NO), the process transitions to standby mode.

[0051] In step S07, the ECU100 monitors the charge level. The process in step S07 will be described in detail later.

[0052] Next, with reference to Figure 3, the relay life calculation in step S03 shown in Figure 2 will be explained. In step S11, the ECU 100 reads the number of operations N of the charge / discharge relay 26. In step S12, following step S11, the ECU 100 reads the number of days D that have been used for the charge / discharge relay 26.

[0053] In step S13, following step S12, the ECU 100 reads the total number of days of life of the charge / discharge relay 26, Dtotal, and reads the total number of relay lifespans for the charge / discharge relay 26, Ntotal.

[0054] In step S14, following step S13, the ECU 100 calculates the number of life cycle operations N' per elapsed days of the charge / discharge relay 26 based on equation (f01). N' = Ntotal × D / Dtotal (f01)

[0055] Next, referring to Figure 4, the operation mode monitoring in step S05 shown in Figure 2 will be explained. In step S21, the ECU 100 reads the management unit time Tm. In step S22, following step S21, the ECU 100 queries the HEMS 11 for the operation mode M.

[0056] In step S23, following step S22, the ECU 100 determines the response result from HEMS 11. If the response from HEMS 11 is grid-connected (step S23: YES), the process proceeds to step S24. If there is no response from HEMS 11 (step S23: NO), the process proceeds to step S25.

[0057] In step S24, the ECU 100 sets the operating mode M to the charge level monitoring mode. In step S25, the ECU 100 sets the operating mode M to the "other" mode.

[0058] Next, referring to Figure 5, we will explain the charge amount monitoring in step S07 shown in Figure 2. In step S31, the ECU 100 reads the management unit time Tm.

[0059] In step S32, following step S31, the ECU 100 sets the time counter t to 0. In step S33, following step S32, the ECU 100 sets the V2H charge amount Ep to 0. In step S34, following step S33, the ECU 100 sets the vehicle power consumption amount Ec to 0. The processing from step S32 to step S33 is an initialization process.

[0060] In step S35, following step S34, the ECU 100 receives the V2H charging power Pi from the HEMS 11. In step S36, following step S35, the ECU 100 receives the vehicle power consumption Pc. The vehicle power consumption Pc is calculated, for example, by dividing the vehicle sensor value by the design value.

[0061] In step S37, following step S36, the ECU 100 calculates ΔEp based on equation (f02). ΔEp = Pi × Δt (f0²)

[0062] In step S38, following step S37, the ECU 100 calculates ΔEc based on equation (f03). ΔEc = Pc × Δt (f03) The process from step S35 to step S38 is a calculation process for the charge and discharge amount per period Δt.

[0063] In step S39, following step S38, the ECU 100 calculates the V2H charge amount Ep by adding ΔEp. In step S40, following step S39, the ECU 100 calculates the vehicle power consumption Ec by adding ΔEc. In step S41, following step S40, the ECU 100 calculates the elapsed time t by adding Δt. The processing from step S39 to step S41 is the calculation process of the charge / discharge amount per management unit time Tm.

[0064] In step S42, following step S41, the ECU 100 determines whether the elapsed time t has exceeded the management unit time Tm. If the elapsed time t has exceeded the management unit time Tm (step S42: YES), the process proceeds to step S43. If the elapsed time t has not exceeded the management unit time Tm (step S42: NO), the process proceeds to step S44.

[0065] In step S43, the ECU 100 determines whether the V2H charge amount Ep exceeds the vehicle power consumption Ec. If the V2H charge amount Ep exceeds the vehicle power consumption Ec (step S43: YES), the process proceeds to step S32. If the V2H charge amount Ep does not exceed the vehicle power consumption Ec (step S43: NO), the process proceeds to step S44.

[0066] In step S44, the ECU 100 sends a stop request to the HEMS 11. In step S45, following step S44, the ECU 100 determines whether or not a stop instruction has been sent from the HEMS 11. If a stop instruction has been sent from the HEMS 11 (step S45: YES), the HEMS 11 stops the V2H charging. If a stop instruction has not been sent from the HEMS 11 (step S45: NO), the vehicle 20 stops the V2H charging.

[0067] The embodiments have been described above with reference to specific examples. However, this disclosure is not limited to these specific examples. Modifications made to these specific examples by those skilled in the art are also included within the scope of this disclosure, as long as they retain the features of this disclosure. The elements, their arrangement, conditions, shapes, etc., of each of the aforementioned specific examples are not limited to those illustrated and can be modified as appropriate. The elements of each of the aforementioned specific examples can be combined in different ways as appropriate, as long as no technical inconsistencies arise.

[0068] [Note] [Note 1] A power supply device that can supply power to the outside from a power source inside the vehicle, A relay connected between the power source and the power supply device, It comprises a power supply device and a control device for controlling relays, The control device is If the system determines that the number of operations exceeds the relay's lifespan, it will continue in standby mode without sending a stop request to an external source. If it determines that the amount of external charging per unit time is less than the vehicle's power consumption, it will output a stop request to the outside. A charge / discharge system that monitors the external charge level when it receives a command to enter charge level monitoring mode from an external source.

[0069] In this disclosure, a power storage device 29 is exemplified as a power source, a power converter 27 as a power supply device, a charge / discharge relay 26 as a relay, and an ECU 100 as a control device. According to Appendix 1, optimal V2H control is possible by determining the operating mode (grid-connected / independent operation) while suppressing vehicle power consumption and the number of relay operations.

[0070] According to this disclosure, as described in step S07 of Figure 2 and steps S43 to S44 of Figure 5, the V2H charge amount Ep per management unit time Tm is monitored, and when it falls below the vehicle power consumption Ec, a stop request is sent from the vehicle 20 to the HEMS 11. Thus, a V2H stop / standby decision can be made based on charge amount monitoring.

[0071] According to this disclosure, as explained in step S04 of Figure 2 and in Figure 3, if the cumulative number of operations N of the charge / discharge relay 26 exceeds the lifespan operation count N' per elapsed days, the vehicle 20 can continue in standby mode without requesting a stop from the HEMS 11.

[0072] According to this disclosure, as explained in steps S05 and S06 of Figure 2 and in Figure 4, the charge level can be monitored when a power saving mode (charge level monitoring mode) is received from the HEMS 11 (management server 200) with which the system is linked. Energy-saving mode (charge level monitoring mode): When connected to the grid and when there is a power outage and HEMS11 is set to "energy-saving priority". Other: Cases where there is a power outage and HEMS11 is not set to "energy saving priority," and cases where HEMS11 is unresponsive (including unsupported cases). [Explanation of Symbols]

[0073] 10: Housing 11: HEMS 20: Vehicles 100: ECU 26: Charge / Discharge Relay 27: Power converter 29: Energy storage device

Claims

[Claim 1] A power supply device that can supply power to the outside from a power source inside the vehicle, A relay connected between the power source and the power supply device, The system comprises the power supply device and a control device for controlling the relay, The control device is If it is determined that the number of operations exceeds the relay lifespan of the aforementioned relay, the system will continue in standby mode without outputting a stop request to the outside. If it determines that the amount of external charging per unit time is less than the vehicle's power consumption, it will output a stop request to the outside. A charge / discharge system that monitors the external charge level when it receives a command to enter charge level monitoring mode from an external source.

Images