Power management device

Abstract

To provide a power management device that can easily and surely ensure the charge amount of an in-vehicle storage battery with a simple structure.SOLUTION: The present invention includes: an in-vehicle storage battery 2; at least one residential storage battery 3; one of a system power source 4 and a renewable energy power source 5; an energy distributor 6 for connecting one of the system power source and the renewable energy power source to the in-vehicle storage battery and the residual storage battery, and supplying power to one of the in-vehicle storage battery and the in-vehicle storage battery while distributing the power; and a controller 7 for controlling the energy distributor 6. The controller 7 controls the power storage amount of the in-vehicle battery 2 and the power storage amount of the residential storage battery 3 on the basis of a predetermined threshold value set in advance for the power storage capacity of the in-vehicle storage battery 2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power management device that manages power while utilizing both an in-vehicle storage battery and a residential storage battery that store power supplied from a grid power supply or a renewable energy power supply. [Background technology]

[0002] In recent years, there has been an increase in power conversion devices that support V2H, which allows users to utilize onboard storage batteries in electric vehicles and residential storage batteries during disasters, etc. In addition to grid power sources, there has also been an increase in the use of renewable energy sources such as solar cells as the power supply to storage batteries.

[0003] One known example of the above-mentioned conventional device is a power conversion device that uses both a stationary (residential) storage battery and an on-board storage battery, while ensuring the stored power of the on-board storage battery for driving (see, for example, Patent Document 1). This device uses a power index value based on the magnitude of grid power to start and stop discharging from the stationary storage battery and charging to the on-board storage battery based on four thresholds: discharge start threshold, discharge end threshold, charge start threshold, and charge end threshold. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-189012 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while conventional devices increase the chances of charging the onboard battery by using four thresholds based on the changing power index value of the grid power, and thus increase the likelihood that the onboard battery will have sufficient stored power in the event of sudden use, this is not necessarily reliable. Furthermore, the need to set four thresholds to start and end discharging and charging makes the configuration complex.

[0006] Furthermore, the power index value is based on the magnitude of grid power and does not take into account the power of renewable energy sources, and it is expected that when renewable energy sources are primarily used, the transition of the power index value will be complex, making it difficult to apply. Furthermore, if stationary storage batteries and on-board storage batteries, which have different uses, are charged and discharged using the same standard using the power index value of grid power, there may be cases where the charge amount of the on-board storage battery cannot be sufficiently secured.

[0007] An object of the present invention is to provide a power management device that uses both an in-vehicle storage battery and a residential storage battery, and that can easily and reliably ensure the charge amount of the in-vehicle storage battery with a simple configuration. [Means for solving the problem]

[0008] In order to achieve the above object, the power management device of the present invention comprises an on-board storage battery, at least one residential storage battery, a system power source or a renewable energy power source, an energy distributor that connects the system power source or the renewable energy power source to the on-board storage battery and the residential storage battery and distributes and supplies power to the on-board storage battery or the residential storage battery, and a controller that controls the energy distributor and controls the amount of power stored in the on-board storage battery and the amount of power stored in the residential storage battery based on a predetermined threshold value that is set in advance regarding the amount of power stored in the on-board storage battery.

[0009] According to this configuration, the amount of electricity stored in the vehicle storage battery and the amount of electricity stored in the residential storage battery are controlled based only on the predetermined threshold value related to the amount of electricity stored, so that the amount of charge in the vehicle storage battery can be easily and reliably ensured with a simple configuration.

[0010] Preferably, the controller prioritizes charging of the on-board storage battery when the charging rate, which is the level of the amount of electricity stored in the on-board storage battery relative to a preset storage battery capacity, is equal to or lower than a charging rate threshold, which is one of the predetermined thresholds, and charges the residential storage battery when the charging rate of the on-board storage battery is higher than the charging rate threshold. Therefore, since charging of the on-board storage battery is prioritized based on the charging rate threshold of the on-board storage battery, it is possible to more easily and reliably ensure the amount of charge of the on-board storage battery with a simple configuration.

[0011] Preferably, the system selects one of the in-vehicle storage battery and the residential storage battery to be charged, allocates a maximum charge amount of the grid power supply or renewable energy power supply to the selected storage battery, and allocates a charge amount equal to the difference between the maximum charge amount and the maximum charge amount of the selected storage battery to the unselected storage battery. In this case, allocation to the in-vehicle storage battery and the residential storage battery can be performed appropriately according to the selected storage battery to be charged.

[0012] Preferably, the energy distributor and the controller are installed in a power conditioner that converts power from the grid power supply or the renewable energy power supply, which enables the device to be simplified in configuration and reduced in size. [Effects of the Invention]

[0013] In this invention, the amount of electricity stored in the vehicle storage battery and the amount of electricity stored in the residential storage battery are controlled based on a predetermined threshold value related to the amount of electricity stored in the vehicle storage battery that is set in advance. Furthermore, for example, when the state of charge of the vehicle storage battery is equal to or lower than the threshold value, charging of the vehicle storage battery is prioritized, and when the state of charge of the vehicle storage battery is higher than the threshold value, charging of the residential storage battery is prioritized. This makes it possible to easily and reliably ensure the amount of electricity stored in the vehicle storage battery with a simple configuration. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a block diagram illustrating a power management apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing a controller in the device. [Figure 3] FIG. 1 is a diagram specifically illustrating the device. [Figure 4] 1(A) to 1(C) are schematic diagrams showing the operation of the device. [Figure 5] (A) and (B) are diagrams illustrating the operation of the device. [Figure 6] 3 is a flowchart showing the operation of the present device. [Figure 7] 3 is a flowchart showing the operation of the present device. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram showing a power management device 1 according to one embodiment of the present invention. This power management device 1 includes an on-board storage battery 2, a residential (stationary) storage battery 3, a grid power supply 4, a renewable energy power supply 5 such as a solar cell (PV), an energy distributor 6 that connects the grid power supply 4, the solar cell (PV) 5, the on-board storage battery 2, and the residential storage battery 3 and distributes and supplies power to the on-board storage battery 2 or the residential storage battery 3, and a controller 7 that controls the energy distributor 6 and controls the amount of power stored in the on-board storage battery 2 and the residential storage battery 3 based on a predetermined threshold value related to the amount of power stored in the on-board storage battery 2. The energy distributor 6 and the controller 7 are installed in a power conditioner 8 that converts power from the grid power supply 4 and the renewable energy power supply 5.

[0016] The energy distributor 6 includes a bidirectional DC / AC converter (inverter) 10, a DC / DC converter 11, and two DC / DC converters 12 and 13. For example, a single-phase three-wire system power supply 4 is connected to the bidirectional DC / AC converter 10, and a solar cell (PV) 5 is connected to the DC / DC converter 11. The outputs of the bidirectional DC / AC converter 10 and the DC / DC converter 11 are connected to the vehicle storage battery 2 via the first bidirectional DC / DC converter 12 and to the residential (stationary) storage battery 3 via the second bidirectional DC / DC converter 13, respectively. Each of the converters 10, 11, 12, and 13 is connected to the controller 7.

[0017] As another example of Figure 1, there is also included a configuration in which a DC / DC converter 11 and a bidirectional DC / AC converter (inverter) 10 for PV5 are built into a V2H dedicated stand (not shown), a bidirectional DC / DC converter 12 for the on-board storage battery 2 is provided at the interface between the V2H dedicated stand and the vehicle, the DC / DC converter 11 for PV5, the bidirectional DC / AC converter (inverter) 10 and the bidirectional DC / DC converter 12 for the on-board storage battery 2 are connected at one point, a connector is connected to the bidirectional DC / DC converter 12 for the on-board storage battery 2 and the connector is connected to the vehicle, and other configurations are the same as those of Figure 1.

[0018] 2, the controller 7 includes a maximum charge amount (discharge amount) allocation unit 15 that allocates the maximum charge amount (discharge amount) to the on-board storage battery 2 and the fixed storage battery 3, an on-board storage battery charge priority selection unit 16 that prioritizes and selects charging of the on-board storage battery 2, a charge rate threshold setting unit 17 that sets a threshold for the charge rate, which is the level of the amount of electricity stored in the charged on-board storage battery 2 relative to the battery capacity of the on-board storage battery 2, a comparison unit 18 that compares the charge rate of the on-board storage battery 2 detected by an on-board storage battery charge rate detection unit 21 with the set charge rate threshold, and a charge priority execution unit 19 that prioritizes and executes charging of the on-board storage battery 2 or the fixed storage battery 3. The charge rate of the fixed storage battery 3 is detected by a fixed storage battery charge rate detection unit 22.

[0019] 3, the energy distributor 6 allocates charge / discharge power Pc1 and Pd1 to the vehicle storage battery 2 and allocates charge / discharge power Pc2 and Pd2 to the residential storage battery 3 from the total (maximum) charge power Pc and the total (maximum) discharge power Pd based on a predetermined charge / discharge power allocation standard. A user interface 9 is connected to the controller 7, which is connected to a setting unit 17, etc., where a user sets a charging rate threshold for the vehicle storage battery.

[0020] The comparison unit 12 in Fig. 2 compares the charging rate detected by the vehicle-mounted battery 2 with a preset charging rate threshold for the vehicle-mounted battery 2, and the charging priority execution unit 13 prioritizes charging of the vehicle-mounted battery 2 if the charging rate (SOCv in Fig. 3) of the vehicle-mounted battery 2 does not exceed the charging rate threshold (SOCv-set in Fig. 3), that is, if it is less than or equal to the charging rate threshold, and charges the fixed battery 3 if the charging rate of the vehicle-mounted battery 2 is greater than the charging rate threshold. In Fig. 3, the charging rate of the fixed battery 3 is indicated by SOCh.

[0021] Figures 4(A) to (C) show the operation of this device. In Figure 4(A), when the charging rate of the on-board storage battery 2 is below the charging rate threshold, charging of the on-board storage battery 2 is prioritized. P0 indicates the input from the grid power supply 4 or the renewable energy power supply 5, and P1 is the maximum charging power of the on-board storage battery 2.

[0022] For example, surplus power from the photovoltaic (PV) 5 is input as input P0 to the energy distributor 6. When it is detected that the charging rate of the on-board battery 2 is equal to or lower than the charging rate threshold, charging of the on-board battery 2 is started with priority at the maximum charging power P1. Charging of the on-board battery 2 is given priority as long as the amount of power generated does not exceed the current capacity of the on-board battery 2. If the generated power exceeds the current capacity of the on-board battery 2 while the on-board battery 2 is being charged, the excess power is used to charge the fixed battery 3, which is charged with the charging power P0-P1. If the PV 5 is generating power while the on-board battery 2 is not connected to the energy distributor 6, such as while the vehicle is running, the fixed battery 3 is charged.

[0023] As shown in Fig. 4(B), when it is detected that the charge rate of the in-vehicle battery 2 exceeds the charge rate threshold value, the charging of the in-vehicle battery 2 is stopped, and it is charged with the input P0 to the stationary battery 3. As shown in Fig. 4(C), if power is required during the charging of the stationary battery 3, the discharge is performed only from the stationary battery 3. In this case, the in-vehicle battery 2 is not discharged, and the power of the in-vehicle battery 2 is used only for running.

[0024] In Figs. 4(A) and (B), the in-vehicle battery 2 or the stationary battery 3 is charged using the input P0 of the power supplied from the utility power supply 4 or the solar cell (PV) 5. However, when the power is not supplied, that is, when the input P0 is 0, the charging power of the stationary battery 3 or the in-vehicle battery 2 may be used.

[0025] Figs. 5(A) and (B) show a state (load-following charging and load-following discharging) in which, while supplying power to the domestic load 23, for example, charging and discharging are performed on the stationary battery 3. In Fig. 5(A), for example, the power from the utility power supply 4 protected by a CT (current transformer) and other generators 24 is supplied to the domestic load 23 via the changeover switch 25, and load-following charging is performed in which it is forward-converted by the bidirectional DC / AC converter (inverter) 10 and charged to the stationary battery 3. In Fig. 5(B), while supplying the power from the utility power supply 4 and the generators 24 to the domestic load 2 via the changeover switch 25, load-following discharging is performed in which it is reverse-converted by the bidirectional DC / AC converter (inverter) 19 and the power from the stationary battery 3 is discharged.

[0026] The lower limit of the remaining amount of the stationary battery 3 in load-following charge and discharge is set by the user. For example, when the charge rate SOC value (%) of the stationary battery 3 is such that (depletion level SOCA + 2%) < SOC, the charging start time to the charging end time (for example, 23:00 to 7:00) is load-following charging + surplus charging available, and the charging end time to the discharge start time (for example, 7:00 to 10:00) is only surplus charging. Here, the depletion level SOCA refers to the level at which the stored power is left during the normal use of the battery. Surplus charging is available when it drops from (SOCA + 2%) or more, and load-following charging + surplus charging is available when it rises from below SOCA.

[0027] When SOCA < SOC ≤ (SOCA + 2%), the charging start time to the charging end time is load-following charging + surplus charging, and the charging end time to the discharging start time is either with surplus charging or load-following charging + surplus charging. When SOC ≤ SOCA, both the charging start time to the charging end time and the charging end time to the discharging start time are load-following charging + surplus charging. The threshold value of load-following charging follows the value calculated from the preset contract amperage and the margin.

[0028] For the discharging start time to the discharging end time (for example, 10:00 to 23:00), when (SOCA + 2%) < SOC, it is load-following discharging + surplus charging, and when SOCA < SOC ≤ (SOCA + 2%), it is either load-following discharging + surplus charging or only surplus charging. When SOC ≤ SOCA, and for the discharging end time to the charging start time (for example, 23:00), they are the same as the above-described operations respectively.

[0029] Thereby, while supplying power to the household load, the lower limit of the remaining amount of the stationary battery 3 in the load-following charge and discharge that performs charge and discharge on the stationary battery can be appropriately and easily set by the user.

[0030] It is also possible to discharge the power stored in the in-vehicle battery 3 and supply the power to the household load 23.

[0031] Figures 6 and 7 are flowcharts showing the operations of the present power management device 1. Figure 6 shows the operation of allocating the maximum charge amount to the in-vehicle battery and the residential battery according to the selected charge target. Figure 7 shows the operation of prioritizing the charge and discharge of the in-vehicle battery and the residential battery based on the charge rate threshold of the in-vehicle battery.

[0032] First, in Fig. 6, the total (maximum) charge amount (total (maximum) discharge amount) Pchrg-t / Pdschrg-t is calculated based on the operation mode and settings of the device (step S1). Next, it is determined whether both the vehicle-mounted storage battery and the residential (stationary) storage battery should be charged (discharged) (step S2). If both should be charged (discharged), it is determined whether the vehicle-mounted storage battery should be given priority for charging (discharging) (step S3). If both should not be charged (discharged), a determined charge amount (discharge amount) is allocated to each of the vehicle-mounted storage battery and the residential (stationary) storage battery, taking into account the maximum charge amount (maximum discharge amount) of each storage battery (step S4), and the process ends.

[0033] If the priority for charging (discharging) is given to the on-board battery in step S3, it is determined whether the total (maximum) charge amount (total (maximum) discharge amount) is greater than the maximum power of the on-board battery (step S5). If it is greater, the maximum charge amount (maximum discharge amount) is allocated to the on-board battery. The charge amount that is the difference between the maximum charge amount (maximum discharge amount) and the maximum charge amount (maximum discharge amount) of the on-board battery is allocated to the residential (stationary) battery (step S6), and the process ends. If it is not greater, the maximum charge amount (maximum discharge amount) is allocated to the on-board battery, but not to the residential (stationary) battery (step S7), and the process ends.

[0034] If the priority for charging (discharging) is not given to the vehicle-mounted storage battery in step S3, it is determined whether the total (maximum) charge amount (total (maximum) discharge amount) is greater than the maximum power of the residential (stationary) storage battery (step S8). If it is greater, the maximum charge amount (maximum discharge amount) is allocated to the vehicle-mounted storage battery. The charge amount that is the difference between the maximum charge amount (maximum discharge amount) and the maximum charge amount (maximum discharge amount) of the vehicle-mounted storage battery is allocated to the residential (stationary) storage battery (step S9), and the process ends. If it is not greater, the maximum charge amount (maximum discharge amount) is allocated to the residential (stationary) storage battery, but not to the vehicle-mounted storage battery (step S10), and the process ends.

[0035] This allows appropriate allocation to the vehicle storage battery and the residential (stationary) storage battery depending on the storage battery to be charged that is selected.

[0036] 7, it is determined whether the state of charge (SOC) of the vehicle-mounted storage battery (SOCv) is smaller than (or equal to) the state of charge threshold value SOCv-set of the vehicle-mounted storage battery (step S21). If it is smaller than (or equal to), the vehicle-mounted storage battery is given priority during charging, and the residential (stationary) storage battery is given priority during discharging (step S22), and the process ends. If it is larger than (or equal to), the residential (stationary) storage battery is given priority during charging, and the vehicle-mounted storage battery is given priority during discharging (step S23), and the process ends.

[0037] This will reduce the cost of on-board batteries. Charge Rate Threshold Based on this, the in-vehicle storage battery is given priority during charging, and the residential (fixed) storage battery is given priority during discharging, so that the amount of charge for the in-vehicle storage battery can be easily and reliably ensured with a simple configuration.

[0038] Thus, the present invention includes an on-board battery charging priority selection unit 16 that selects charging of the on-board battery 2 as a priority, a charging rate threshold setting unit 17 for the on-board battery 2, a comparison unit 18 that compares the detected charging rate of the on-board battery 2 with the charging rate threshold, and a charging priority execution unit 19 that prioritizes charging of the on-board battery 2 or the residential (fixed) battery 3; when the charging rate of the on-board battery 2 is equal to or lower than the charging rate threshold for the on-board battery, charging of the on-board battery 2 is prioritized, and when the charging rate of the on-board battery 2 is higher than the charging rate threshold, charging of the residential (fixed) battery 3 is performed, so that the amount of charge of the on-board battery 2 can be easily and reliably ensured with a simple configuration.

[0039] Here, when a group of storage batteries with a fixed capacity is to be managed, a threshold value for the absolute value of the amount of stored power may be used as the threshold value for the amount of stored power in the storage batteries instead of the charging rate threshold value.

[0040] In the above embodiment, a solar cell (PV) is exemplified as a renewable energy power source, but fuel cells (FC), wind power generation (WP), cogeneration power sources, geothermal power generation, biomass power generation, etc. may also be used.

[0041] The present invention is not limited to the above-described embodiments, and various additions, modifications, and omissions are possible without departing from the spirit of the present invention. Therefore, such additions, modifications, and omissions are also included in the scope of the present invention. [Explanation of symbols]

[0042] 1: Power management device 2: On-board battery 3: Residential (fixed) storage battery 4: Grid power supply 5: Renewable energy sources (solar photovoltaic (PV)) 6: Energy distributor 7: Controller 8: Power conditioner 15: Maximum charge (discharge) allocation section 16: On-board battery charging priority selection unit 17: Vehicle battery charge rate threshold setting unit 18: Comparison section 19: Charging priority execution unit

Claims

1. An on-board battery, at least one residential battery; a grid power source or a renewable energy power source; an energy distributor that connects the system power supply or the renewable energy power supply to the vehicle storage battery and the residential storage battery, and distributes and supplies electric power to the vehicle storage battery or the residential storage battery; a controller that controls the energy distributor and controls the amount of electricity stored in the vehicle storage battery and the amount of electricity stored in the residential storage battery based on a predetermined threshold value that is set in advance regarding the amount of electricity stored in the vehicle storage battery. The controller When a charging rate, which is a level of the amount of stored power of the charged vehicle-mounted storage battery relative to a storage battery capacity preset for the vehicle-mounted storage battery, is equal to or lower than a charging rate threshold value set by a user, which is one of the predetermined threshold values, the vehicle-mounted storage battery is given priority during charging, and the residential storage battery is given priority during discharging, When the charging rate of the vehicle-mounted storage battery is greater than the charging rate threshold, the residential storage battery is given priority during charging, and the vehicle-mounted storage battery is given priority during discharging, A power management device that selects a priority of charging and discharging between the vehicle storage battery and the residential storage battery based on the user's setting of a charging rate threshold.

2. In claim 1, a power management device that selects one of the in-vehicle storage battery and the residential storage battery to be charged, allocates a maximum charge amount of the grid power source or the renewable energy power source to the selected storage battery, and allocates a charge amount that is the difference between the maximum charge amount and the maximum charge amount of the selected storage battery to the unselected storage battery.

3. In claim 1, The power management device, wherein the energy distributor and the controller are installed in a power conditioner that converts power from the grid power supply or the renewable energy power supply.

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