Charge control device

Abstract

Charging control device (10) comprising a control unit (101) which controls the charging and discharging of a power storage device (11), wherein the control unit (101) calculated a predicted minimum value of a limit value of an electrical charging power for the power storage device (11) (S113), receives from the external charging device a nominal value of a minimum supplyable electrical power of an external charging device (3) (S112), determines whether the predicted minimum value is less than the nominal value or not (S113), when it is determined that the predicted minimum value is not less than the nominal value, a charging is controlled such that the charging of the power storage device (11) by the external charging device (3) is carried out in a first operating mode (S114), wherein the first operating mode is an operating mode in which a lower limit of a command value of an electrical supply power from the external charging device (3) is set to the nominal value, if it is determined that the predicted minimum value is less than the nominal value, the charging is controlled such that the charging of the power storage device (11) by the external charging device (3) is carried out in a second operating mode (S118, S125, S118A, S135), wherein the second operating mode is different from the first operating mode and is an operating mode in which the lower limit of the command value is set to an estimated value of the minimum supplyable electrical power of the external charging device (3), wherein the estimated value is less than the nominal value, and The charging is controlled in such a way that the charging is carried out in the second operating mode by using as the command value an electrical power between a current limit value of the electrical charging power for the power storage device (11) and the estimated value (S118, S125, S118A, S135).

Description

BACKGROUND OF THE INVENTION

[0001] The present disclosure relates to a charge control device, and more particularly to a charge control device including a control unit that controls charging and discharging of a power storage device. Description of the related art

[0002] Conventionally, a technique for stopping charging when an abnormality is detected in a control of charging of a power storage device from an external charging device is known (see, for example, Japanese Patent No. JP 5 673 062 B2). SUMMARY

[0003] Fig. Figure 7 shows a relationship between a minimum rated electric power of a charger or a charging device and an electric charging power limit of a charging device. Referring to Fig. 7, a minimum rated output current is set for a DC charging device designed to perform fast charging. Consequently, in principle, control for charging a power storage device with an electric power less than a minimum electric output power corresponding to the minimum rated output current is impossible. In addition, when the power storage device is charged with an electric power that exceeds a charging electric power limit value Win for the power storage device, the power storage device is stressed, resulting in a malfunction or a short lifespan of the power storage device. Consequently, when a charging electric power limit value Win of the power storage device is predicted to fall below the minimum electric output power corresponding to the charging device's minimum output current (after a time t1 in Fig. 7), that is, when a predicted minimum value of Win < the minimum electric output power of the charging device is satisfied, the electric charging power for the power storage device exceeds the predicted minimum value of the threshold value Win, thus exceeding the threshold value Win with a high probability. Consequently, charging is stopped to protect the power storage device. As a result, charging can be carried out safely.

[0004] In the charging device, although control for charging the power storage device with a minimum actual electric output power less than the minimum rated electric output power is actually possible, in some cases, a notification of the minimum rated electric output power being higher than the minimum actual electric output power may be provided on the power storage device side. In this case, charging is stopped even though charging can actually continue, which may make it impossible to perform charging as much as possible.

[0005] US 2018 / 0 345 798 A1 describes a vehicle comprising a high-voltage battery, a battery heating unit, and an electrical component, such as a DC-DC converter, which can be supplied with electrical energy from an external power supply. The vehicle comprises a state-of-charge detection unit that detects a value of the output voltage of the high-voltage battery, a current supply amount detection unit that detects the amount of current supplied to the electrical component, and a control unit that controls an on-vehicle charger such that, when the output voltage is greater than or equal to a voltage threshold and the supplied current is less than or equal to a threshold, charging of the high-voltage battery performed by the external power supply is stopped, and electrical power is supplied from the high-voltage battery to the electrical component.

[0006] The present disclosure has been made to solve the above-described problem, and an object of the present disclosure is to provide a charging control device that enables charging to continue safely as much as possible.

[0007] This object is achieved by a charging control device according to claim 1. Advantageous further developments are specified in the dependent claims.

[0008] A charging control device according to the present disclosure includes a control unit that controls charging and discharging of a power storage device. The control unit calculates a predicted minimum value of a limit value of charging electric power for the power storage device, obtains a nominal value of a minimum supplyable electric power of an external charging device from the external charging device, determines whether the predicted minimum value is less than the nominal value, and, if it is determined that the predicted value is not less than the nominal value, controls charging such that charging of the power storage device from the external charging device is carried out in a first mode, the first mode being a mode in which a lower limit of a command value of supply electric power from the external charging device is set to the nominal value.If it is determined that the predicted minimum value is less than the rated value, charging such that charging of the power storage device from the external charging device is carried out in a second mode, the second mode being different from the first mode and being a mode in which the lower limit of the command value is set to an estimated value of the minimum supplyable electric power of the external charging device, the estimated value being less than the rated value, and controlling charging such that charging is carried out in the second mode by using, as the command value, an electric power between a current limit value of the electric charging power for the power storage device and the estimated value.

[0009] With such a configuration, even if the predicted minimum value of the charging electric power limit for the power storage device is less than the rated value of the minimum supplyable electric power of the external charging device, charging is performed by using, as the command value, the electric power between the current charging electric power limit for the power storage device and the estimated value of the minimum supplyable electric power of the external charging device. Therefore, even if the predicted minimum value is less than the rated value of the minimum supplyable electric power, charging can be continued as much as possible. In addition, charging can be continued so as not to exceed the current charging electric power limit.As a result, a charging control device can be provided that enables charging to continue safely as far as possible.

[0010] Preferably, the control unit controls charging such that charging is started in the second mode by using, as the command value, a start-time electric power between the threshold value and the estimated value, detects a supply electric power supplied from the external charging device to the power storage device, determines whether or not a difference between the detected supply electric power and the command value is smaller than a prescribed value, and continues charging when it is determined that the difference is smaller than the prescribed value.

[0011] With such a configuration, charging is started by using the starting time electric power between the current limit value of the charging electric power for the storage device and the estimated value of the minimum supplyable electric power of the external charging device as the command value, and charging is continued when the difference between the supply electric power from the external charging device to the power storage device and the command value is smaller than the prescribed value. As a result, charging can be continued as much as possible.

[0012] Further, when determining that the difference is smaller than the prescribed value, the control unit preferably continues charging by using, as the command value, an electric power higher than the start-time electric power within a range not exceeding the limit value.

[0013] With such a configuration, when the difference between the electric power supplied from the external charging device to the power storage device and the command value is smaller than the prescribed value, charging is continued by using, as the command value, the electric power higher than the start-time electric power within a range that does not exceed the current limit of the charging electric power for the power storage device. As a result, charging can be continued safely.

[0014] Preferably, the control unit controls charging such that charging in the second mode is carried out by using as the command value a value obtained by subtracting a correction value from the limit value, detects a supply electric power supplied from the external charging device to the power storage device, determines whether or not the detected supply electric power exceeds the limit value, and decreases the correction value and continues charging when it is determined that the detected supply electric power does not exceed the limit value.

[0015] With such a configuration, charging is controlled such that charging is performed by using the value obtained by subtracting the correction value from the current charging electric power limit value for the power storage device as the command value, reducing the correction value, and continuing charging when the electric power supplied from the external charging device to the power storage device does not exceed the limit value. As a result, charging can be continued safely as much as possible.

[0016] The above and other objects, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description of the present disclosure when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWING Fig. 1 schematically shows an overall configuration of a known charging system to which the present embodiment is applicable. Fig. 2 shows in more detail the configuration of a charging system according to the embodiment. Fig. 3 is a flowchart showing a flow of a specific charge control process in a first embodiment. Fig. 4 shows an example of a progress of a store in the first embodiment. Fig. 5 is a flowchart showing a flow of a specific charge control process in a second embodiment. Fig. 6 shows an example of the flow of charging in the second embodiment. Fig. 7 shows a relationship between a minimum rated electric power of a charging device and an electric charging power limit of a charging device. DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment]

[0017] Embodiments of the present disclosure will be described in detail below with reference to the notation, in which the same or corresponding portions are denoted by the same reference numerals, and a description thereof will not be repeated. <Konfiguration des Ladesystems>

[0018] Fig. 1 schematically shows an overall configuration of a charging system 9 to which the present embodiment is applicable. Referring to Fig. 1, a charging system 9 comprises a user's vehicle 1, a charger or charging device 3, and a charging cable 4 extending from the charging device 3.

[0019] The vehicle 1 is, for example, an electric vehicle having a battery 11 (see below Fig. 2) attached thereto. The vehicle 1 can perform "external charging" for charging the battery 11 with electric power supplied from the charging device 3 in a state where the vehicle 1 is electrically connected to the charging device 3 through the charging cable 4. The vehicle 1 can be any vehicle as long as it can perform external charging. The vehicle 1 can be a plug-in hybrid vehicle or a fuel cell vehicle.

[0020] The charging device 3 is located, for example, at a public charging station (also referred to as a "charging point" or "charging station"). The charging device 3 converts an alternating current (for example, a three-phase 200 V) supplied by a commercial power supply into a direct current (DC) and supplies the DC power to the vehicle 1.

[0021] In the present embodiment, the charging device 3 is a charging device configured to perform rapid charging. Furthermore, for the charging device 3 according to the present embodiment, a minimum rated electric power corresponding to a minimum outputtable rated current is predetermined and stored. The charging device 3 transmits the minimum electric power to the vehicle 1 when charging the battery 11 of the vehicle 1 starts.

[0022] Fig. Figure 2 shows in more detail the configuration of a charging system 9 according to the embodiment. Referring to the Fig. 1 and Fig. 2, the vehicle 1 includes the battery 11, a monitoring unit 111, a system main relay (SMR) 121, a power control unit (PCU) 122, a motor generator (MG) 123, a drive power transmission 124, a drive wheel 125, an electronic control unit (ECU) 10, and a data communication module (DCM) 19.

[0023] The battery 11 is a rechargeable power storage device and includes a secondary battery, such as a lithium-ion secondary battery or a nickel-metal hydride battery. The battery 11 supplies the PCU 122 with electric power to generate a driving force of the vehicle 1. In addition, the battery 11 is charged with electric power generated by regenerative braking of the motor generator 123 or with electric power supplied from the charging device 3. Instead of the battery 11, a capacitor, such as an electric double-layer capacitor, may be used.

[0024] The monitoring unit 111 monitors a state of the battery 11. Although not shown, the monitoring unit 111 includes a voltage sensor, a current sensor, and a temperature sensor. The voltage sensor detects a voltage Vb of the battery 11. The current sensor detects a current Ib input to and output from the battery 11. The temperature sensor detects a temperature of the battery 11. Each sensor outputs the detection result to the ECU 10. The ECU 10 can calculate a state of charge (SOC) of the battery 11 based on the detection result by each sensor.

[0025] The SMR 121 is electrically connected between the battery 11 and the PCU 122. Closing / opening of the SMR 121 is controlled according to a command from the ECU 10.

[0026] The PCU 122 is a power converter that performs power conversion between the battery 11 and the motor generator 123 according to a command from the ECU 10. The PCU 122 includes an inverter that receives electric power from the battery 11 and drives the motor generator 123, a converter that adjusts a level of a DC voltage applied to the inverter (both the inverter and the converter are not shown), and the like.

[0027] The motor generator 123 is an alternating current motor. The motor generator 123 is driven by the inverter included in the PCU 122 and rotates a drive shaft. Torque output by the motor generator 123 is transmitted to the drive wheel 125 through the drive transmission 124, thereby causing the vehicle 1 to travel. During braking of the vehicle 1, the motor generator 123 receives rotational force from the drive wheel 125 and generates electric power. The electric power generated by the motor generator 123 is charged into the battery 11 through the PCU 122.

[0028] The vehicle 1 further includes a charging relay 131, power lines PL and GL, and an inlet 135 as a configuration for rapid charging.

[0029] The charging device 3 comprises a control device 30 and an electrical power supply unit 31. The charging cable 4 comprises a power line 42, a communication line 43 and a connection device 41.

[0030] During rapid charging of the battery 11, the connector 41 of the charging cable 4 is coupled to the inlet 135. Electrical power from the charging device 3 is supplied to the vehicle 1 through the power line 42 in the charging cable 4 and transmitted to the charging relay 131 via the power lines PL and GL.

[0031] The charging relay 131 and the SMR 121 are electrically connected between the battery 11 and the inlet 135. When the charging relay 131 is closed and the SMR 121 is closed, power transfer between the inlet 135 and the battery 11 becomes possible.

[0032] The ECU 10 is connected to and can communicate with the DCM 19 and the like via a wired vehicle-mounted network such as a CAN (Controller Area Network). In a state where the vehicle 1 is connected to the charging device 3 through the charging cable 4, the ECU 10 is also capable of bidirectional communication with the controller 30 of the charging device 3 through the communication line 43 in the charging cable 4 and the vehicle-mounted network 16.

[0033] The DCM 19 is a communication unit capable of wireless communication with an external device such as a server 8. The DCM 19 includes a communication module that conforms to, for example, a communication standard such as W-CDMA (Wideband Code Division Multiple Access) or LTE (Long Term Evolution), or a wireless LAN (Local Area Network) standard such as IEEE (Institute of Electrical and Electronic Engineers) 802.11. Although not shown, communication between the DCM 19 and the server 8 is performed through a server of a communication service provider using the DCM 19; a server, a base station, and a communication line of a communication carrier; a WAN (Wide Area Network) such as the Internet; and a communication network such as a wireless LAN in a factory.

[0034] The ECU 10 includes a central processing unit (CPU) 101, a memory 102, a communication unit 103, an input / output port (not shown) through which various signals are input and output, and the like. The ECU 10 controls the devices (such as the SMR 121, the PCU 122, and the charging relay 131) in the vehicle 1 so that the vehicle 1 enters a desired state. The ECU 10 corresponds to a "charging control device" according to the present disclosure.

[0035] Conventionally, a technique has been known for stopping charging when an abnormality in the control of charging of the battery 11 by the charging device 3 is detected.

[0036] A minimum rated output current is set for the charging device 3 configured to perform rapid charging. Consequently, in principle, controlling charging of the battery 11 with an electric power less than the minimum electric power corresponding to the minimum rated output current is impossible. In addition, if the battery 11 is charged with an electric power that exceeds a limit value Win of the charging electric power for the battery 11, the battery 11 will be stressed, resulting in a malfunction or a short service life of the battery 11.Therefore, when the charging electric power threshold Win of the battery 11 is predicted to fall below the minimum electric power corresponding to the minimum output current of the charging device 3, that is, when a predicted minimum value of Win < the minimum electric power of the charging device 3 is satisfied, the charging electric power for the battery 11 exceeds the predicted minimum value of the threshold Win, thus exceeding the threshold Win with a high probability. Consequently, charging is stopped to protect the battery 1. As a result, charging can be performed safely.

[0037] In the charging device 3, although control for charging the battery 11 with a minimum actual electric power lower than the minimum rated electric power is actually possible, in some cases, notification of the minimum rated electric power higher than the minimum actual electric power may be provided to the battery 11 side. In this case, charging is stopped even though charging can actually continue, which may make it impossible to perform charging as much as possible.

[0038] Accordingly, the CPU 101 of the ECU 10 according to the present disclosure calculates a predicted minimum value of a limit value Win of a charging electric power for the battery 11, obtains a nominal value of a minimum supplyable electric power of the charging device 3 from the charging device 3, determines whether the calculated predicted minimum value is less than the obtained nominal value, and, if it is determined that the predicted minimum value is not less than the nominal value, controls charging such that the charging of the battery 11 by the charging device 3 is carried out in a normal mode, the normal mode being a mode in which a lower limit of a command value of a supply electric power from the charging device 3 is the nominal value. If it is determined that the predicted minimum value is less than the nominal value, controls charging such thatthat the charging of the battery 11 by the charging device 3 is carried out in an estimation mode, wherein the estimation mode is different from the normal mode and is a mode in which the lower limit of the command value is an estimated value of the minimum supplyable electric power of the charging device 3, the estimated value being smaller than the nominal value, and it controls charging such that the charging is carried out in the estimation mode by using as the command value an electric power between a current limit value of the charging electric power for the battery 11 and the estimated value.

[0039] Thus, even if the predicted minimum value of the charging electric power limit for the battery 11 is less than the rated value of the minimum supplyable electric power of the charging device 3, charging is performed by using, as the command value, the electric power between the current charging electric power limit for the battery 11 and the estimated value of the minimum supplyable electric power of the charging device 3. Consequently, even if the predicted minimum value is less than the rated value of the minimum supplyable electric power, charging can be continued as much as possible. In addition, charging can be continued so as not to exceed the current charging electric power limit. As a result, charging can be continued safely as much as possible.

[0040] The control in the present embodiment will be described below. Fig. 3 is a flowchart illustrating a flow of a special charge control process in a first embodiment. The special charge control process is called from a higher-level process at every predetermined time period and executed by the CPU 101 of the ECU 10.

[0041] With reference to Fig. 3, the CPU 101 determines whether or not it is time to start charging the battery 11 of the vehicle 1 (step S111). The determination is based, for example, on whether or not communication between the ECU 10 of the vehicle 1 and the controller 30 of the charging device 3 has been started before the start of charging.

[0042] If the CPU 101 determines that it is time to start charging (YES, step S111), the CPU 101 obtains the minimum rated electric power A stored in the charging device 3 from the controller 30 of the charging device 3 via the communication line 43 of the charging cable 4, the vehicle-mounted network 16, and the communication unit 103 by communicating with the charging device 3 (step S112). The CPU 101 calculates a predicted minimum value of a threshold value Win of a charging electric power based on a deterioration state, a temperature, and an SOC of the battery 1, and determines whether the calculated predicted minimum value of Win is less than the obtained minimum electric power A (predicted minimum value of Win < A) (step S113).

[0043] When the CPU 101 determines that the predicted minimum value of Win < A is not satisfied (NO in step S113), that is, when the CPU 101 determines that the predicted minimum value of Win ≥ A is satisfied, the CPU 101 controls charging so that charging is started in a normal mode according to the obtained minimum electric power A (step S114). The normal mode is a mode for executing charging by using, as a command value for the charging device 3, a prescribed electric power between an upper limit and a lower limit, where the upper limit is a current limit value Win of the charging electric power, and the lower limit is a known minimum electric power of the charging device 3.

[0044] When the CPU 101 determines that the predicted minimum value of Win < A is satisfied (YES in step S113), the CPU 101 makes an inquiry to the server 8 as to whether or not information about a minimum electric power B of the charging device 3 is stored in the server 8 (step S115).

[0045] When, according to an electric power command value smaller than the minimum rated electric power A of the charging device 3, the charging device 3 can supply the electric power indicated by the command value to the battery 11 during charging of the battery 11 by the charging device 3, the CPU 101 of the ECU 10 of the vehicle 1 transmits the electric power value to the server 8 as the minimum electric power information B of the charging device 3. The server 8 stores the electric power value indicated by the minimum electric power information B of the charging device 3 used by the vehicle 1, transmitted from the DCM 19 of the vehicle 1, together with information that can identify the charging device 3.When the CPU 101 of the ECU 10 of the vehicle 1 makes a request for the information on the minimum electric power B of the charging device 3, the server 8 transmits the information to the vehicle 1 if the server 8 stores the information on the minimum electric power B of the charging device 3.

[0046] The CPU 101 determines whether the information about the minimum electric power B of the charging device 3 is stored in the server 8 and whether the information has been transmitted from the server 8 via the DCM 19, the vehicle-mounted network 16, and the communication unit 103 (step S116). If the CPU 101 determines that the information has been transmitted (YES in step S116), the CPU 101 controls charging so that charging is started in the normal mode according to the minimum electric power B indicated by the information (step S117).

[0047] In contrast, when the CPU 101 determines that the information has not been transmitted (NO in step S116), the CPU 101 controls charging to start charging in an estimation mode using an estimated value of the minimum electric power of the charging device 3 as the command value (step S118). The estimation mode is a mode for executing charging by using, as the command value, a prescribed electric power between an upper limit and a lower limit at the charging device 3, where the upper limit is the current limit value Win of the charging electric power, and the lower limit is the estimated value of the minimum electric power (an unknown minimum electric power) of the charging device 3.The estimated value may, for example, be a value defined as the minimum electrical power in standards for charging devices, such as the charging device 3, or it may be a value (for example, an average value of research results) based on results of a market survey on the minimum electrical power in the type of charging device 3.

[0048] If the CPU 101 determines that it is not time to start charging (NO in step S111), the CPU 101 determines whether the current operation mode is the estimation mode or not (step S121) after step S114, step S117, and step S118. If the CPU 101 determines that the current operation mode is not the estimation mode (NO in step S121), the CPU 101 returns to a process executed at a parent process from which the current process is called.

[0049] In contrast, if the CPU 101 determines that the current operation mode is the estimation mode (YES in step S121), the CPU 101 determines whether or not the prescribed seconds have elapsed since the start of loading in the estimation mode (step S122). If the CPU 101 determines that the prescribed seconds have not elapsed (NO in step S122), the CPU 101 returns to an operation to be executed at a parent operation from which the current operation is called.

[0050] In contrast, when the CPU 101 determines that the prescribed seconds have elapsed (YES in step S122), the CPU 101 determines whether or not the actual electric power supplied from the charging device 3 to the battery 11 is closely analogous to the estimated value of the minimum electric power of the charging device 3, which is the command value for the charging device 3 (step S123). Whether or not the actual electric power supplied is closely analogous to the estimated value is determined based on, for example, whether or not a difference between the actual electric power supplied and the estimated value is within a prescribed error.When the CPU 101 determines that the actual supply electric power is not closely analogous to the estimated value (NO in step S123), that is, when the charging device 3 cannot output the estimated value as the actual supply electric power, the CPU 101 stops charging (step S124), returning to a process to be executed at a higher process from which the current process is called.

[0051] In contrast, when the CPU 101 determines that the actual supply electric power is closely analogous to the estimated value (YES in step S123), the CPU 101 specifies the current limit value Win of the charging electric power of the battery 11 and continues charging by using Win as the command value (step S125). The CPU 101 transmits the estimated value to the server 8 as the information about the minimum electric power of the charging device 3 (step S126). Thereafter, the CPU 101 switches the operation mode from the estimation mode to the normal operation mode (step S127) and returns to a process to be executed at a higher-level process from which the current process is called.

[0052] Fig. 4 shows an example of the flow of charging in the first embodiment. Referring to Fig. 4, at the start of charging, charging is started by using the estimated value of the minimum electric power of the charging device 3 as the command value. If the minimum rated electric power of the charging device 3 is correct, the threshold value Win of the charging electric power of the battery 11 at this time falls below the minimum rated electric power at time t1. In principle, the charging device 3 cannot output electric power less than or equal to the minimum rated electric power, thus determining that the charging device 3 cannot output electric power less than or equal to the threshold value Win, and charging can be stopped.

[0053] However, in the present embodiment, charging is started using the estimated value of the minimum electric power of the charging device 3, and if the charging device 3 can output the electric power indicated by the estimated value, charging is continued. At time t2, it is determined that the prescribed seconds have elapsed from the start of charging using the estimated value, and charging is continued using the threshold value Win at that time as the command value of the charging electric power. Thus, even if the predicted minimum value of the charging electric power of the battery 11 is smaller than the minimum rated electric power of the charging device 3, charging can be continued as much as possible. In addition, charging can be continued so as not to exceed the current charging electric power threshold value Win.As a result, charging can continue as safely as possible. [Second embodiment]

[0054] In the first embodiment, charging is controlled such that charging is started in the estimation mode by using as the command value the start-time electric power (estimated value in the first embodiment) between the current limit value of the charging electric power of the battery 11 and the estimated value of the minimum electric power of the charging device 3, and when the difference between the actual supply electric power from the charging device 3 to the battery 11 and the estimated value is smaller than the prescribed value, charging is continued.When the difference is smaller than the prescribed value, charging is continued by using, as the command value, the electric power (current limit value Win in the first embodiment) higher than the start-time electric power within a range not exceeding the current limit value Win of the charging electric power.

[0055] In a second embodiment, charging is controlled such that charging is carried out in the estimation mode by using, as the command value, a value obtained by subtracting a correction value from the current limit value Win of the charging electric power of the battery 11. When the actual electric power supplied from the charging device 3 to the battery 11 does not exceed the limit value Win, the correction value is reduced and charging is continued. Regarding the correction value, the value obtained by subtracting the correction value from the current limit value Win of the charging electric power of the battery 11 is adjusted so as not to fall below the estimated value of the minimum electric power of the charging device 3.

[0056] Fig. Fig. 5 is a flowchart showing a flow of a special charge control process in the second embodiment. The special charge control process is called from a higher-level process at every prescribed time period and executed by the CPU 101 of the ECU 10. Referring to Fig. 5, steps S111 to S117 are the same as those in Fig. 3, whereby a corresponding description is not repeated.

[0057] In step S116, if the CPU 101 determines that the minimum electric power B information of the charging device 3 is not stored in the server 8 and has not been transmitted from the server 8 (NO in step S116), the CPU 101 controls charging to start charging in the estimation mode by using, as the command value, the value obtained by subtracting the correction value from the current limit value Win of the charging electric power of the battery 11 (step S118A). Regarding the correction value, the value obtained by subtracting the correction value from the current limit value Win of the charging electric power of the battery 11 is adjusted so as not to fall below the estimated value of the minimum electric power of the charging device 3.

[0058] If the CPU 101 determines that it is not time to start charging (NO in step S111), after step S114, after step S117, and after step S118A, the CPU 101 determines whether the current operation mode is the estimation mode or not (step S131). If the CPU 101 determines that the current operation mode is not the estimation mode (NO in step S131), the CPU 101 returns to an operation to be executed at a higher-level operation from which the current operation is called.

[0059] In contrast, when the CPU 101 determines that the current operation mode is the estimation mode (YES in step S131), the CPU 101 determines whether or not the current time is the time for each prescribed period of time from the start of charging in the estimation mode (step S132). The prescribed period of time may be the same as or different from the prescribed period of time at which the special charge control operation is called. If the CPU 101 determines that the current time is not the time for each prescribed period of time (NO in step S132), the CPU 101 returns to an operation to be executed at a higher-level operation from which the current operation is called.

[0060] In contrast, when the CPU 101 determines that the current time is the time for each prescribed period (YES in step S132), the CPU 101 determines whether the actual electric power supplied from the charging device 3 to the battery 11 is less than or equal to the current limit value Win of the charging electric power of the battery 11 (step S133). When the CPU 101 determines that the actual electric power supplied is not less than or equal to the current limit value Win (NO in step S133), that is, when the actual electric power supplied exceeds the limit value Win, the CPU 101 stops charging (step S134) and returns to a process to be executed at a higher-level process from which the current process is called.

[0061] In contrast, if the CPU 101 determines that the actual supply electric power is less than or equal to the threshold value Win (YES in step S133), the CPU 101 decreases the correction value and continues charging (step S135). The correction value may be decreased at a prescribed rate or by a prescribed amount.

[0062] Then, the CPU 101 determines whether the correction value has become zero, that is, whether the actual electric power supply has become equal to the threshold value Win (step S136). If the CPU 101 determines that the actual electric power supply has not become equal to the threshold value Win (NO in step S136), the CPU 101 returns to a process to be executed at a higher-level process from which the current process is called.

[0063] In contrast, when the CPU 101 determines that the actual electric power supply has become equal to the threshold value Win (YES in step S136), the CPU 101 transmits the value of the actual electric power supply at that time to the server 8 as the minimum electric power information of the charging device 3 (step S137). Thereafter, the CPU 101 switches the operation mode from the estimation mode to the normal operation mode (step S138) and returns to an operation to be executed at a higher-level operation from which the current operation is called.

[0064] Fig. 6 shows an example of the charging process in the second embodiment. Referring to Fig. 6, charging is started by using as the command value the value obtained by subtracting the correction value from the current limit value Win of the charging electric power of the battery 11. Then, the correction value is decreased every prescribed period of time. If the minimum rated electric power of the charging device 3 is correct, the limit value Win of the charging electric power of the battery 11 at this time falls below the minimum rated electric power at time t1. In principle, the charging device 3 cannot output electric power less than or equal to the minimum rated electric power, thus determining that the charging device 3 cannot output electric power less than or equal to the limit value Win, and charging can be terminated.

[0065] However, in the present embodiment, charging is performed using the command value obtained by subtracting the correction value from the threshold value Win, and the correction value is set such that the value obtained by subtracting the correction value from the threshold value Win does not fall below the estimated value of the minimum electric power of the charging device 3. When the actual supply electric power corresponding to the command value obtained by subtracting the correction value from the threshold value Win does not exceed the threshold value Win, that is, when the charging device 3 can output the electric power indicated by the command value, charging is continued.Thus, even if the predicted minimum value of the charging electric power of the battery 11 is less than the minimum rated electric power of the charging device 3, charging can be continued as much as possible. In addition, charging can be continued without exceeding the current charging electric power limit Win. As a result, charging can be continued safely as much as possible. [Modification]

[0066] (1) In the first embodiment described above, as shown in step S118 in Fig. 3, the estimated value is a predetermined value. However, the present disclosure is not limited to this, and the estimated value at the start of charging may be searched for. Specifically, when the predicted minimum value of the threshold value Win of the charging electric power of the battery 11 is smaller than the minimum electric power A obtained by the charging device 3 at the start of charging, the command value of the charging device 3 may be gradually decreased from the minimum electric power A, and the electric power when the actual supply electric power no longer decreases may be defined as the estimated value of the minimum electric power.

[0067] (2) In the second embodiment described above, as described in step S136 in Fig. 5, when it is determined that the actual electric supply power has become equal to the threshold value Win, steps S137 and S138 are executed. However, the present disclosure is not limited to this, and even when the actual electric supply power has not become equal to the threshold value Win, steps S137 and S138 may be executed when it is determined that a prescribed period of time has elapsed.

[0068] (3) In the above-described embodiment, as shown in step S112 in Fig. 3, the minimum electric power A is received by the CPU 101 from the control device 30 of the charging device 3 through the communication line 43 of the charging cable 4 of the vehicle 1, the vehicle-mounted network 16, and the communication unit 103. As shown in step S116 in Fig. 3, the information about the minimum electric power B is received by the CPU 101 from the server 8 through the DCM 19 of the vehicle 1, the vehicle-mounted network 16, and the communication unit 103.

[0069] However, the present disclosure is not limited to this; the information about the minimum electric power A may be received by the CPU 101 from the controller 30 of the charging device 3 through the DCM 19 of the vehicle 1, the vehicle-mounted network 16, and the communication unit 103 through wireless communication. Additionally, the information about the minimum electric power B may be received by the CPU 101 from the server 8 via the controller 30 of the charging device 34, the communication line 43 of the charging cable 4 of the vehicle 1, the vehicle-mounted network 16, and the communication unit 103.In addition to the communication method described above, the communication unit by the CPU 101 of the ECU 10, such as the communication regarding the minimum electric power A and the minimum electric power B, may be executed by using any other communication method such as PLC (Power Line Communication) communication or CAN communication.

[0070] (4) In the embodiment described above, the operations in the Fig. 3 and Fig. 5 by the CPU 101 of the ECU 10 of the vehicle 1. However, the present disclosure is not limited thereto, and the operations in the Fig. 3 and Fig. 5 can be executed by a dedicated ECU for charge control. The charge control ECU can be built into the ECU 10 or can be mounted separately from the ECU 10. [Conclusion]

[0071] 1) As it is in Fig. 2, the ECU 10 includes the CPU 101, which controls the charging and discharging of the battery 11. As shown in the Fig. 3 and Fig. 5, CPU 101 calculates a predicted minimum value of a limit value Win of a charging electric power for the battery 11 (step S113), obtains a minimum electric power A of the charging device 3 from the charging device 3 (step S112), determines whether the predicted minimum value is less than the minimum electric power A or not (step S113), and, when it is determined that the predicted minimum value is not less than the minimum electric power A, controls charging such that charging of the battery 11 by the charging device 3 is carried out in a normal mode (step S114). The normal mode is a mode in which a lower limit of a command value of the supply electric power from the charging device 3 is set to the minimum electric power A, which is the rated value.that the predicted minimum value is less than the minimum electric power A, the charging such that the charging of the battery 11 by the charging device 3 is carried out in an estimation mode (step S118, step S125, step S118A, step S135), wherein the estimation mode is different from the normal mode and is a mode in which the lower limit of the command value is set to an estimated value of the minimum electric power of the charging device 3, the estimated value being less than the minimum electric power A, which is the nominal value, and it controls the charging such that the charging is carried out in the estimation mode by using as the command value an electric power between a current limit value Win of the charging electric power for the battery 11 and the estimated value (step S118, step S125, step S118A, step S135).

[0072] Thus, even if the predicted minimum value of the charging electric power limit value Win of the battery 11 is smaller than the rated minimum electric power of the charging device 3, charging is performed by using, as the command value, the electric power between the current charging electric power limit value Win of the battery 11 and the estimated minimum electric power value of the charging device 3. Consequently, even if the predicted minimum value is smaller than the rated minimum electric power value, charging can be continued as much as possible. In addition, charging can be continued so as not to exceed the current charging electric power limit value Win. As a result, charging can be continued safely as much as possible.

[0073] (2) As it is in Fig. 3, the CPU 101 controls charging such that charging is started in the estimation mode by using, as the command value, a start-time electric power between the threshold value Win and the estimated value (step S118), detects the supply electric power supplied from the charging device 3 to the battery 11 (step S123), determines whether or not a difference between the detected supply electric power and the command value is smaller than a prescribed value (step S123), and continues charging when it is determined that the difference is smaller than the prescribed value (step S125).

[0074] Thus, charging is started by using the starting time electric power between the current limit value Win of the charging electric power of the battery 11 and the estimated value of the minimum electric power of the charging device 3 as the command value, and charging is continued when the difference between the electric power supplied from the charging device 3 to the battery 11 and the command value is smaller than the prescribed value. As a result, charging can be continued as much as possible.

[0075] (3) As it is in Fig. 3, when it is determined that the difference is smaller than the prescribed value, the CPU 101 continues charging by using, as the command value, the electric power higher than the start-time electric power within a range not exceeding the threshold value Win (step S125).

[0076] Thus, when the difference between the electric power supplied from the charging device 3 to the battery 11 and the command value is smaller than the prescribed value, charging is continued by using, as the command value, the electric power higher than the starting time electric power within the range not exceeding the current limit value Win of the charging electric power of the battery 11. As a result, charging can be continued safely.

[0077] (4) As it is in Fig.5, the CPU 101 controls the charging such that the charging is carried out in the estimation mode by using, as the command value, a value obtained by subtracting a correction value from the limit value Win (step S118A, step S135), detects the supply electric power supplied from the charging device 3 to the battery 11 (step S133), determines whether or not the detected supply electric power exceeds the limit value Win (step S133), and decreases the correction value and continues the charging when it is determined that the detected supply electric power does not exceed the limit value Win (step S135).

[0078] Thus, charging is controlled such that charging is performed by using, as the command value, the value obtained by subtracting the correction value from the current limit value Win of the charging electric power of the battery 11, reducing the correction value, and continuing charging when the electric power supplied from the charging device 3 to the battery 11 does not exceed the limit value Win. As a result, charging can be continued safely as much as possible.

[0079] While the embodiments of the present disclosure have been described, it is to be understood that the embodiments disclosed herein are in all respects illustrative and not restrictive. The scope of the present disclosure is defined by the terms of the claims and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0080] A CPU (101), when it is determined that the predicted minimum value of a limit value of a charging power is not less than the minimum power of a charging device (3) (S113), controls charging such that charging is carried out in a normal mode (S114), wherein the normal mode is a mode in which a lower limit of a command value of a supply power is the minimum power; when it is determined that the predicted minimum value is less than the minimum power, it controls charging such that charging is carried out in an estimation mode (S118, S125), which is a mode in which the lower limit of the command value is an estimated value of the minimum power of the charging device, the estimated value being less than the minimum power, and it controls charging such that charging is carried out in the estimation mode,by using as the command value a power between a current limit value of the charging power and the estimated value (S118, S125).,

Claims

[1] A charging control device (10) comprising a control unit (101) that controls charging and discharging of a power storage device (11), wherein the control unit (101) calculates (S113) a predicted minimum value of a limit value of an electric charging power for the power storage device (11), receives a nominal value of a minimum supplyable electrical power of an external charging device (3) from the external charging device (S112), determines whether the predicted minimum value is less than the nominal value or not (S113), when it is determined that the predicted minimum value is not less than the rated value, controlling charging such that charging of the power storage device (11) from the external charging device (3) is carried out in a first mode (S114), the first mode being a mode in which a lower limit of a command value of electric supply power from the external charging device (3) is set to the rated value, if it is determined that the predicted minimum value is smaller than the rated value, controlling the charging such that the charging of the power storage device (11) by the external charging device (3) is carried out in a second mode (S118, S125, S118A, S135), wherein the second mode is different from the first mode and is a mode in which the lower limit of the command value is set to an estimated value of the minimum supplyable electric power of the external charging device (3), the estimated value being smaller than the rated value, and controls the charging such that the charging is carried out in the second mode by using as the command value an electric power between a current limit value of the charging electric power for the power storage device (11) and the estimated value (S118, S125, S118A, S135). [2] Charging control device (10) according to claim 1, wherein the control unit (101) controls the charging such that the charging is started in the second mode by using as the command value a starting time electric power between the limit value and the estimated value (S118), detecting (S123) an electric supply power supplied from the external charging device (3) to the power storage device (11), determines whether a difference between the detected electric power and the command value is smaller than a prescribed value or not (S123), and continues charging when it is determined that the difference is smaller than the prescribed value (S125). [3] The charging control device (10) according to claim 2, wherein, when it is determined that the difference is smaller than the prescribed value, the control unit (101) continues charging by using, as the command value, an electric power higher than the start-time electric power within a range not exceeding the limit value (S125). [4] Charging control device (10) according to claim 1, wherein the control unit (101) controls the charging such that the charging is carried out in the second mode by using as the command value obtained by subtracting a correction value from the limit value (S118A, S135), detecting (S133) the electrical supply power supplied from the external charging device (3) to the power storage device (11), determines whether the detected electrical supply power exceeds the limit value or not (S133), and reduces the correction value and continues charging if it is determined that the detected electric supply power does not exceed the limit (S135).

Images