vehicle

Abstract

To speedily mitigate polarization of a power storage device for travel after end of external charge.SOLUTION: A vehicle 100 comprises a main battery 115, an auxiliary battery 140, a charge relay 110, a DC / DC converter 135, and an ECU 170. The charge relay 110 is used for executing external charge in which the main battery 115 is charged by a power facility 200. The DC / DC converter 135 steps down discharge power of the main battery 115 and supplies stepped-down power to the auxiliary battery 140. The ECU 170 controls the DC / DC converter 135. The ECU 170 pulls down a charge state of the auxiliary battery 140 from a first state to a second state until end of the external charge and drives the DC / DC converter 135 after the end of the external charge.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This disclosure relates to a vehicle.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2022-133689 (Patent Document 1) discloses a vehicle. This vehicle includes a all-solid-state battery (power storage device) and an arithmetic unit. The arithmetic unit calculates the remaining amount of the all-solid-state battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An electric vehicle generally includes a first power storage device for running, a second power storage device for auxiliary equipment, and a converter, and may further include charging equipment for performing external charging to charge the first power storage device by an external power facility outside the vehicle. The converter steps down the discharge power of the first power storage device and supplies the stepped-down power to the second power storage device. As a result, the second power storage device is charged.

[0005] When continuous charging such as external charging is performed, polarization of the first power storage device may be caused. This polarization preferably causes a decrease in the estimation accuracy of the full charge capacity of the first power storage device and is preferably relaxed promptly after the end of external charging.

[0006] This disclosure has been made to solve the above problems, and an object thereof is to provide a vehicle capable of promptly relaxing the polarization of a power storage device for running after the end of external charging.

Means for Solving the Problems

[0007] The vehicle of this disclosure comprises a first energy storage device for driving, a second energy storage device for auxiliary equipment, charging equipment, a converter, and a control device. The charging equipment is used to perform external charging, which charges the first energy storage device using power equipment outside the vehicle. The converter is configured to step down the discharge power of the first energy storage device and supply the stepped-down power to the second energy storage device. The control device controls the converter. The control device reduces the charge state of the second energy storage device from the first state to the second state by the end of external charging, and drives the converter after the end of external charging.

[0008] The above configuration makes it easier to drive the converter to the extent that the polarization of the first energy storage device is largely eliminated. As a result, the polarization of the first energy storage device can be quickly mitigated.

[0009] Preferably, the discharge power when driving the converter by reducing the charge state to the second state is greater than the discharge power when driving the converter without reducing the charge state to the second state.

[0010] The polarization of the first energy storage device is more easily relieved as the discharge power of the first energy storage device increases. By using the above configuration, the polarization of the first energy storage device can be relieved (resolved) more quickly after external charging.

[0011] Preferably, the control device is configured to perform an estimation process to estimate the full charge capacity of the first energy storage device. If the control device reduces the charge state to the second state and drives the converter, it performs the estimation process at least one hour after the completion of external charging. If the control device does not drive the converter after the completion of external charging, it performs the estimation process at least two hours after the completion of external charging. The first hour is shorter than the second hour.

[0012] By adopting the above configuration, when the charge state is reduced to the second state and the converter is driven, polarization can be resolved more reliably, and the estimation process can be started earlier than when the converter is not driven after the completion of external charging.

[0013] Preferably, the first energy storage device includes an all-solid-state battery.

[0014] In all-solid-state batteries, uneven reaction and polarization are easily induced in the depth direction of the cells. By adopting the above configuration, polarization of the first energy storage device can be quickly mitigated in a vehicle that includes an all-solid-state battery in the first energy storage device. [Effects of the Invention]

[0015] According to this disclosure, the polarization of the energy storage device for driving can be quickly reduced after the completion of external charging. [Brief explanation of the drawing]

[0016] [Figure 1] This is a diagram showing the overall configuration of a vehicle according to the embodiment. [Figure 2] This is a diagram illustrating pump-and-charge control. [Figure 3] This is a diagram illustrating polarization relaxation control. [Figure 4] This diagram illustrates the processes performed by the ECU (Electronic Control Unit). [Figure 5] This flowchart illustrates an example of a process related to external charging. [Figure 6] This flowchart illustrates another example of a process related to external charging. [Modes for carrying out the invention]

[0017] Embodiments of this disclosure will be described in detail below with reference to the drawings. The same or corresponding parts in the drawings will be denoted by the same reference numerals and their descriptions will not be repeated. Each of the embodiments and its modifications may be combined with one another as appropriate.

[0018] FIG. 1 is a diagram showing the overall configuration of a vehicle according to an embodiment. Referring to FIG. 1, vehicle 100 is a BEV (Battery Electric Vehicle) and is connected to power facility 200. Power facility 200 is provided outside vehicle 100.

[0019] Vehicle 100 includes inlet 105, charging relay 110, main battery 115 (first power storage device), and sensor unit 116. Vehicle 100 further includes SMR (System Main Relay) 120, PCU (Power Control Unit) 125, and MG (Motor Generator) 130. Vehicle 100 further includes DC / DC converter 135, auxiliary battery 140 (second power storage device), auxiliaries 145, sensor unit 150, and ECU 170.

[0020] Inlet 105 is connected to connector 205 of power facility 200. Inlet 105 receives the power supplied from power supply device 202 of power facility 200. In this example, the supplied power is DC power. Charging relay 110 is a charging device for performing external charging of vehicle 100 and is controlled to be in a closed state during external charging. External charging is to charge main battery 115 with the power supplied from power supply device 202.

[0021] Main battery 115 stores the power for running vehicle 100. Main battery 115 is a battery pack including a plurality of cells. Each cell is a lithium-ion battery, and in this example, is a all-solid-state battery. An all-solid-state battery is a battery having a solid electrolyte layer as its electrolyte layer.

[0022] After external charging is complete, polarization of the main battery 115 may occur. This polarization is a phenomenon in which the voltage VBa of the main battery 115 temporarily increases. Polarization can increase the error in the estimated result of the full charge capacity of the main battery 115. After external charging is complete, the polarization will resolve naturally after a sufficiently long time has passed, or it will be mitigated (resolved) when the main battery 115 is discharged. Resolving the polarization means that the polarization has been sufficiently mitigated and the voltage VBa has stabilized. The above polarization is more easily mitigated when the amount of discharged power of the main battery 115 is large, and it is more easily mitigated when the discharge power of the main battery 115 is large.

[0023] The sensor unit 116 includes a current sensor 117 and a voltage sensor 118. The current sensor 117 detects the current IBa of the main battery 115. The voltage sensor 118 detects the voltage VBa of the main battery 115.

[0024] The SMR120 is connected between the main battery 115 and the PCU 125 and DC / DC converter 135. The SMR120 switches between electrical disconnection and connection between the main battery 115 and the PCU 125 and DC / DC converter 135 by switching it on and off.

[0025] The PCU125 converts the discharge power (DC power) of the main battery 115 into AC power. The MG130 receives the AC power from the PCU125 and generates the driving force for the vehicle 100.

[0026] The DC / DC converter 135 steps down its input power IP. The input power IP corresponds to the discharge power of the main battery 115. The DC / DC converter 135 is configured to supply the stepped-down power as its output power OP to the auxiliary battery 140. The output power OP corresponds to the charging power of the auxiliary battery 140. The DC / DC converter 135 is driven when the SMR 120 is in the closed state.

[0027] The auxiliary battery 140 stores the operating power for the auxiliary equipment 145. The auxiliary equipment 145 includes the HMI (Human Machine Interface) device 146, the instrument panel 147, and the lights 148. Each of these auxiliary devices is a low-voltage electrical device that operates by consuming power from the auxiliary battery 140. Each auxiliary device can operate while being externally charged.

[0028] The sensor unit 150 includes a current sensor 152 and a voltage sensor 153. The current sensor 152 detects the current IBb of the auxiliary battery 140. The voltage sensor 153 detects the voltage VBb of the auxiliary battery 140. The higher the charge (storage amount) of the auxiliary battery 140, in other words, the higher the charge state of the auxiliary battery 140, the higher the voltage VBb. This charge state is represented, for example, by the State of Charge (SOC) of the auxiliary battery 140.

[0029] The ECU 170 includes a CPU (Central Processing Unit) 172 and memory 174. The CPU 172 performs various arithmetic operations. The memory 174 includes ROM (Read Only Memory) and RAM (Random Access Memory) (neither of which are shown). The ROM stores the program executed by the CPU 172.

[0030] The ECU 170 controls various devices of the vehicle 100 according to the currents IBa, IBb and voltages VBa, VBb. These devices include a charging relay 110, an SMR 120, a PCU 125, a DC / DC converter 135, and auxiliary equipment 145.

[0031] The ECU 170 determines whether to insert the connector 205 into the inlet 105 based on the signal level from the power equipment 200. The ECU 170 calculates the state of charge (SOC) of the main battery 115 according to the current IBa and voltage VBa. The ECU 170 sets the target voltage of the auxiliary battery 140 and sets the target SOC of the auxiliary battery 140. The ECU 170 controls the input power IP and output power OP by controlling the DC / DC converter 135. The ECU 170 commands the start of external charging by sending a charge start command to the power equipment 200. The ECU 170 commands the end of external charging by sending a charge end command to the power equipment 200.

[0032] The ECU170 is configured to perform a process to estimate the full charge capacity of the main battery 115 after external charging is complete. Hereinafter, this process will also be referred to as the "estimation process". The estimation process is performed when the SMR120 is in the open state. The estimation process is performed based on the OCV (Open Circuit Voltage) of the main battery 115. The estimation process is scheduled to be performed after a predetermined time has elapsed since the last time this process was performed (when the full charge capacity was last estimated). The predetermined time is, for example, one week. When the estimation process is scheduled, it is preferable that the polarization of the main battery 115 is sufficiently relaxed (resolved) in order to avoid the polarization affecting the estimation result of the full charge capacity.

[0033] The ECU170 performs either pump-charge control or polarization relaxation control by controlling the SMR120 to a closed state and driving the DC / DC converter 135. Pump-charge control and polarization relaxation control are the same in that they supply power from the main battery 115 to the auxiliary battery 140 via the DC / DC converter 135, but they differ in their purpose.

[0034] The pump-charge control is performed with the aim of charging the auxiliary battery 140 using the power of the main battery 115 when the voltage VBb drops. This control may also be performed when the vehicle 100 is running or when the SMR 120 is turned off.

[0035] Polarization relaxation control is performed to relax the polarization of the main battery 115 by discharging it after external charging is complete. This control is performed when estimation processing is scheduled after external charging is complete. The pump-out charging control and polarization relaxation control will be described in detail below.

[0036] Figure 2 is a diagram illustrating the pump-charge control. Referring to Figure 2, in each of (A) to (C), the vertical axis represents the voltage VBb.

[0037] In example (A), the voltage VBb is ΔX lower than the target voltage TV of the auxiliary battery 140. The target voltage TV is, for example, TV1. TV1 is equal to the upper limit voltage VU of the auxiliary battery 140, for example, 13V. The upper limit voltage VU is predetermined by experimentation or other means from the standpoint of protecting the auxiliary battery 140. When the voltage VBb reaches the upper limit voltage VU, the ECU 170 stops the DC / DC converter 135. ΔX corresponds to the difference between the upper limit voltage VU and the voltage VBb, and is related to the amount of rechargeable energy in the auxiliary battery 140. In other words, the larger ΔX, the greater this rechargeable energy.

[0038] In example (B), the power of the auxiliary battery 140 is consumed, and the voltage VBb drops to the starting voltage VP. The starting voltage VP is a predetermined voltage that is lower than the target voltage TV by a reference value TH, and in this example it is VP1. VP1 is, for example, 12V. When the voltage VBb drops to the starting voltage VP, the pump-charge control begins.

[0039] In example (C), the auxiliary battery 140 is charged by pump-charge control, and the voltage VBb rises from the starting voltage VP to the target voltage TV. Due to the pump-charge control, the voltage VBb is controlled within the voltage range VR. The voltage range VR is the range of the voltage VBb, with its upper and lower limits being the target voltage TV and the starting voltage VP, respectively. In this example, the voltage range VR is VR1.

[0040] During pump-charge control, the input power IP is P1. In other words, when the voltage VBb drops to the starting voltage VP, the DC / DC converter 135 is driven so that the input power IP is P1.

[0041] Figure 3 is a diagram illustrating polarization relaxation control. Referring to Figure 3, in each of (A) and (B), the vertical axis represents the voltage VBb.

[0042] In example (A), external charging has just finished and estimation processing is scheduled. Prior to estimation processing, the ECU 170 performs polarization relaxation control. Polarization relaxation control is performed until the integrated value of the current IBb from the start reaches a predetermined value. The predetermined value is stored in memory 174 and is determined experimentally in advance as the value at which polarization is eliminated when the integrated value reaches the predetermined value. Due to the polarization relaxation control, the auxiliary battery 140 is charged and the voltage VBb rises ((A)→(B)).

[0043] The input power IP of the DC / DC converter 135 during polarization relaxation control is P2. In other words, if the voltage VBb is less than the target voltage TV (and higher than the starting voltage VP) after the completion of external charging, the DC / DC converter 135 is driven so that the input power IP is P2 prior to the estimation process.

[0044] Continuous charging, such as external charging, may cause polarization in the main battery 115. This polarization leads to a decrease in the accuracy of estimating the full charge capacity of the main battery 115, so it is preferable that it be mitigated as quickly as possible after the completion of external charging.

[0045] In this embodiment, the ECU170 has a configuration to address such problems. This will be explained below.

[0046] FIG. 4 is a diagram for explaining the process executed by the ECU 170. Referring to FIG. 4, in the example of (A), external charging is in progress and ΔX is ΔX1. The state of charge of the auxiliary battery 140 when ΔX is ΔX1 is also referred to as the "first state" (the hatched portion on the right side of (A)). After the external charging ends, the ECU 170 is scheduled to execute the polarization relaxation control by driving the DC / DC converter 135 and execute the estimation process.

[0047] When the SOC of the main battery 115 rises to the reference SOC, the ECU 170 lowers the target voltage TV of the auxiliary battery 140 from TV1 to TV2. The reference SOC is lower than the full charge SOC of the main battery 115. For example, the full charge SOC is 80% and the reference SOC is 60%. TV2 is, for example, 12.5V. When the target voltage TV is lowered to TV2, the start voltage VP is also lowered from VP1 to VP2 (for example, 11.5V). As a result, the voltage range VR drops to VR2 (<VR1). Consequently, the state of charge (charge amount) of the auxiliary battery 140 tends to decrease.

[0048] Until the SOC reaches the full charge SOC, the auxiliaries 145 operate, whereby the power of the auxiliary battery 140 is consumed and the voltage VBb decreases ((A) → (B)). In the example of (B), the voltage VBb is within VR2 and ΔX is ΔX2 (>ΔX1). The state of charge of the auxiliary battery 140 when ΔX is ΔX2 is also referred to as the "second state" (the hatched portion on the right side of (B)). Due to the lowering of the target voltage TV, the state of charge of the auxiliary battery 140 is lowered from the first state to the second state.

[0049] In this way, from the start to the end of the external charging, the ECU 170 lowers the state of charge of the auxiliary battery 140 from the first state to the second state by lowering the target voltage TV (voltage range VR).

[0050] When the State of Charge (SOC) reaches the end of the charge state (SOC), the ECU 170 terminates external charging. After the termination of external charging, the ECU 170 drives the DC / DC converter 135 to perform polarization relaxation control until the integrated value of the current IBb reaches a predetermined value, and then performs estimation processing. Once the estimation processing is complete, the ECU 170 raises (returns) the target voltage TV from TV2 to TV1. This returns the voltage range VR from VR1 to VR2.

[0051] The lower the target voltage TV, the lower the voltage range VR, and therefore the lower the voltage VBb tends to be. The lower the voltage VBb, the larger the ΔX tends to be. The larger the ΔX, the greater the amount of power that can be charged into the auxiliary battery 140. The larger this amount of power, the greater the amount of power that can be discharged into the main battery 115. Therefore, the amount of power that can be discharged into the main battery 115 can be increased, and the polarization of the main battery 115 can be easily reduced.

[0052] As described above, by lowering the target voltage TV (voltage range VR), the charge state of the auxiliary battery 140 can be lowered (ΔX can be increased).

[0053] If ΔX is small, the amount of chargeable power of the auxiliary battery 140 will be small, and the voltage VBb may immediately reach the upper limit voltage VU after the start of branch relaxation control, potentially causing the DC / DC converter 135 to stop. As a result, it may not be possible to drive the DC / DC converter 135 to the extent that the polarization of the main battery 115 is largely resolved (it may not be possible to secure sufficient discharge power for the main battery 115). In this case, it is necessary to wait for a certain period of time after the DC / DC converter 135 stops until the polarization is resolved naturally. Thus, if ΔX is small, it may not be possible to quickly relax (resolve) the polarization.

[0054] In contrast, in this embodiment, ΔX tends to be larger, which increases the rechargeable power of the auxiliary battery 140. Therefore, the above situation can be avoided. In other words, it becomes easier to drive the DC / DC converter 135 to the extent that the polarization of the main battery 115 is largely resolved. As a result, the polarization of the main battery 115 can be relieved more quickly compared to the example where a certain period of time is waited. Therefore, if estimation processing is scheduled after the completion of external charging, the estimation processing can be started earlier.

[0055] The auxiliary components 145 can operate even during external charging. Therefore, in order to avoid insufficient charge in the auxiliary battery 140, it is preferable that the charge state of the auxiliary battery 140 be lowered only when necessary. In this embodiment, the target voltage TV (voltage range VR) is lowered only during the period from when the SOC rises to the reference SOC until the estimation process is completed. This minimizes the length of time during which the auxiliary battery 140 is in a low charge state. Consequently, it becomes easier to avoid situations where the auxiliary battery 140 is insufficient charge.

[0056] It is preferable that the ECU 170 controls the DC / DC converter 135 such that the discharge power of the main battery 115 (P2, which is the input power IP during branch relaxation control) when the auxiliary battery 140 is reduced to the second state and the DC / DC converter 135 is driven is several times greater than the discharge power (P1, which is the input power IP during pump-charge control) when the DC / DC converter 135 is driven without reducing the charge state of the auxiliary battery 140 to the second state.

[0057] The polarization of the main battery 115 after external charging is more easily reduced the larger the discharge power (input power IP) of the main battery 115. By controlling the DC / DC converter 135 as described above, the discharge power of the main battery 115 is increased during branch relaxation control. This allows the polarization of the main battery 115 to be relaxed (resolved) more quickly after external charging.

[0058] Before the estimation process, regardless of whether polarization relaxation control is performed or not, it is preferable that the SMR120 is opened for some time and the main battery 115 remains in an unloaded state in order to more reliably eliminate the polarization of the main battery 115 (stabilize the voltage VBa).

[0059] Even if the target voltage TV is lowered to less than the voltage VBb, the charge state of the auxiliary battery 140 may not be sufficiently lowered (ΔX is small) at the end of external charging, either because external charging is completed in a short time or because the power of the auxiliary battery 140 is not consumed much during external charging. As a result, as in example (C), the voltage VBb may be above the target voltage TV at the end of external charging. In this case, the ECU 170 does not perform branch relaxation control from the perspective of preventing overcharging of the auxiliary battery 140, and controls the SMR 120 to be in the open state for a certain period of time. During this certain period of time, the main battery 115 is in an unloaded state. The length of this certain period of time (duration of the unloaded state) is predetermined as the length of time that polarization naturally relaxes without the DC / DC converter 135 being driven after the end of external charging.

[0060] On the other hand, as in example (B), if the charge state of the auxiliary battery 140 is sufficiently reduced when external charging ends, the DC / DC converter 135 is driven until the polarization is largely resolved (branch mitigation control is performed). After that, the SMR 120 is controlled to the open state, and the no-load state continues. The duration of this no-load state (the open time of the SMR 120) can be shorter than the duration in example (C), but this does not pose a problem from the standpoint of polarization mitigation. This is because the polarization of the main battery 115 has already been largely resolved by the branch mitigation control. In the case of (B), the ECU 170 controls the SMR 120 so that the duration of the no-load state is shorter than in the case of (C).

[0061] If the DC / DC converter 135 is driven by lowering the charge state of the auxiliary battery 140 from the first state to the second state, as in example (B), the ECU 170 performs the estimation process at least one hour after the completion of external charging. On the other hand, if the DC / DC converter 135 is not driven after the completion of external charging, as in example (C), the estimation process is performed at least two hours after the completion of external charging. The first hour is shorter than the second hour. The first hour corresponds to the sum of the execution time of branch relaxation control and the duration of the no-load state in case (B). The second period corresponds to the duration of the no-load state in case (C).

[0062] By adopting this configuration, in case (B), polarization resolution can be more reliably achieved while the estimation process can be started earlier than in case (C).

[0063] Figure 5 is a flowchart illustrating an example of the process related to external charging. This flowchart begins when connector 205 is inserted into inlet 105.

[0064] Referring to Figure 5, the ECU 170 determines whether a predetermined time has elapsed since the last time the estimation process was performed (S105). If the predetermined time has not elapsed (NO in S105), the ECU 170 sets the target voltage TV to V1 and starts external charging in response to a user operation instructing the start of external charging (S111). The process then proceeds to S130. On the other hand, if the predetermined time has elapsed (YES in S105), the ECU 170 confirms that the estimation process is scheduled after external charging (S112). The ECU 170 starts external charging (S115).

[0065] When the ECU 170 determines, based on the current IBa and voltage VBa, that the state of charge (SOC) of the main battery 115 has risen to the reference SOC (S120), it lowers the target voltage TV from V1 to V2 in order to lower the charge state of the auxiliary battery 140 (S125). Subsequently, when the ECU 170 determines that the state of charge (SOC) of the main battery 115 has reached the end of charge (S130), it terminates external charging (S135).

[0066] Figure 6 is a flowchart illustrating another example of the process related to external charging. This flowchart starts after S135 in Figure 5 when the target voltage TV has been lowered (S112, S125 have been executed).

[0067] Referring to Figure 6, the ECU 170 determines whether the voltage VBb at the end of external charging is equal to or greater than the target voltage TV (S205). If the voltage VBb is equal to or greater than the target voltage TV, as in the example in Figure 4(C) (YES in S205), the ECU 170 controls the SMR 120 to the open state (S210). The execution period of S210 corresponds to the second period described above. After S210, the process proceeds to S240.

[0068] As shown in the example in Figure 4(B), if the voltage VBb is less than the target voltage TV (NO in S205), the ECU170 controls the SMR120 to the closed state (S215) and performs polarization relaxation control (S220). This control is performed when the input power IP is P2 (>P1). In the example in Figure 6, it is assumed that the voltage VBb does not drop to the starting voltage VP (the pump-out charging control is not performed).

[0069] The ECU170 determines whether the integrated value of current IBb has reached a predetermined value (S225). If the integrated value has not reached the predetermined value (NO in S225), the process returns to S220 and polarization relaxation control continues. If the integrated value has reached the predetermined value (YES in S225), the ECU170 stops polarization relaxation control (S230) and controls the SMR120 to the open state (S235). The execution period of S215 to S235 corresponds to the first period described above.

[0070] ECU170 uses the voltage VBb after S210 or S235 as the OCV of the main battery 115 and performs estimation processing (S240). After S240, ECU170 raises the target voltage TV from V2 to V1 (S245).

[0071] As described above, according to the embodiment, the ECU 170 lowers the charge state of the auxiliary battery 140 from the first state to the second state by lowering the target voltage TV (voltage range VR) before the end of external charging, and after external charging drives the DC / DC converter 135 to perform polarization relaxation control. This makes it easier to drive the DC / DC converter 135 to the extent that the polarization of the main battery 115 is largely eliminated (making it easier to secure sufficient discharge power for the main battery 115). As a result, the polarization of the main battery 115 can be quickly relaxed.

[0072] In particular, solid-state batteries are prone to polarization. Therefore, the embodiment is especially effective for vehicles equipped with solid-state batteries.

[0073] After continuous charging, such as external charging, reaction unevenness (uneven distribution of lithium ions) may occur in the depth direction of the cells (all-solid-state batteries) of the main battery 115. When reaction unevenness occurs, the area near the electrodes of the cells tends to become locally high voltage. If such a high voltage state continues for a long period of time, it may lead to cell degradation. Therefore, after external charging, it is important not only to alleviate (eliminate) polarization but also to eliminate the above-mentioned reaction unevenness. According to this embodiment, after external charging, it becomes easier to drive the DC / DC converter 135 until the voltage near the cell electrodes drops to a level that prevents cell degradation. Therefore, in addition to alleviating the polarization of the main battery 115, cell degradation can also be suppressed.

[0074] [Other variations] Vehicle 100 is not limited to BEVs, but may also be other types of electric vehicles such as PHEVs (Plug-in Hybrid Electric Vehicles).

[0075] The power supplied by the power supply device 202 may be alternating current power. In this case, the vehicle 100 includes an AC / DC converter as an on-board charging device. The AC / DC converter converts the above-mentioned alternating current power into direct current power for charging the main battery 115. The AC / DC converter and the charging relay 110 also form an example of the “charging equipment” of this disclosure.

[0076] Each cell of the main battery 115 is assumed to be an all-solid-state battery, but it may also be a liquid-type battery such as a liquid-type lithium-ion battery.

[0077] Lowering the charge state of the auxiliary battery 140 from the first state to the second state is equivalent to lowering the target voltage TV from TV1 to TV2, but it may also be equivalent to lowering the target SOC of the auxiliary battery 140 from the first SOC to the second SOC. The first SOC corresponds to TV1. The second SOC corresponds to TV2. [Industrial applicability]

[0078] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0079] 100 vehicles, 105 inlets, 115 main batteries, 120 SMRs, 135 DC / DC converters, 140 auxiliary batteries, 145 auxiliary equipment, 200 power equipment.

Claims

1. It is a vehicle, The first energy storage device for driving, A second energy storage device for auxiliary equipment, A charging device for performing external charging to charge the first energy storage device using external power equipment of the vehicle, A converter configured to reduce the discharge power of the first energy storage device and supply the reduced power to the second energy storage device, The system includes a control device for controlling the converter, The control device is Before the completion of the aforementioned external charging, the charge state of the second energy storage device is reduced from the first state to the second state. A vehicle that drives the converter after the completion of the aforementioned external charging.

2. The vehicle according to claim 1, wherein the discharge power when the converter is driven by reducing the charge state to the second state is greater than the discharge power when the converter is driven without reducing the charge state to the second state.

3. The control device is configured to perform an estimation process to estimate the full charge capacity of the first energy storage device. The control device is When the charging state is reduced to the second state and the converter is driven, the estimation process is executed at least one hour after the external charging is completed. If the converter is not driven after the completion of the external charging, the estimation process is executed at least two hours after the completion of the external charging. The vehicle according to claim 1 or claim 2, wherein the first time is shorter than the second time.

4. The vehicle according to claim 1 or 2, wherein the first energy storage device includes an all-solid-state battery.

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