Vehicle battery charging device

Abstract

To provide a battery charging device of a vehicle which can prevent overdischarge of a battery.SOLUTION: In a vehicle 1 loaded with a battery and an external charging device which can execute external charging for charging power supplied from a power supply outside a vehicle to the battery, a battery charging device 100 comprises: an electric appliance 90 to which the power is supplied from the battery 2; disconnection / connection devices (main contactors) 71, 72 which can disconnect and connect electric connection between the battery and the electric appliance; and a control device which controls the disconnection / connection devices. The control device controls the disconnection / connection devices so that the electric connection between the battery and the electric appliance is disconnected when a connection prohibition condition is established, controls the external charging device so that the external charging is started and controls the disconnection / connection devices so that the battery is electrically connected with the electric appliance when no connection prohibition condition is established when the external charging is requested.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a battery charging device in a vehicle equipped with a battery and an external charging device capable of performing external charging for charging the battery by an external power source outside the vehicle.

Background Art

[0002] Conventionally, there has been known a vehicle equipped with a battery that supplies power to a motor as a drive source and various electrical devices, and capable of charging the battery by an external power source outside the vehicle.

[0003] For example, Patent Document 1 discloses a vehicle including a traveling motor, a high-voltage battery that supplies power to the motor, a charger capable of charging the high-voltage battery by an external power source outside the vehicle, a low-voltage battery having an output voltage lower than that of the high-voltage battery, and a DC / DC converter, and configured such that power is supplied from the high-voltage battery to the low-voltage battery via the DC / DC converter. Here, in the vehicle of Patent Document 1, even when charging the high-voltage battery by an external power source outside the vehicle, the high-voltage battery and the DC / DC converter are electrically connected and the DC / DC converter is driven, so that a part of the power supplied to the high-voltage battery is supplied to the low-voltage battery.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the battery and other electrical devices are electrically connected during charging of the battery by an external power source outside the vehicle as in Patent Document 1, while charging the battery, a part of the power supplied to the battery can be supplied to other electrical devices to properly operate them. However, if the battery and other electrical devices are simply electrically connected whenever a battery charging request is issued, when the power supply to the battery from the external power supply device fails due to a failure of the external power supply device or the like, power will be supplied from the battery to the electrical devices. Therefore, there is a risk of causing over-discharge of the battery.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a battery charging device for a vehicle that can prevent over-discharge of a battery.

Means for Solving the Problem

[0007] To solve the above problems, the present invention provides a battery charging device in a vehicle equipped with a battery and an external charging device capable of performing external charging for charging the battery with power supplied from an external power source outside the vehicle, comprising: an electrical device supplied with power from the battery; a connection / disconnection device capable of disconnecting and connecting the electrical connection between the battery and the electrical device; and a control device for controlling the connection / disconnection device, wherein when a request for the external charging is issued, if a connection prohibition condition that the SOC of the battery is less than a predetermined determination value and the number of charging failures, which is the number of times the external charging has failed, is equal to or more than a predetermined determination number is satisfied, the control device controls the connection / disconnection device so that the electrical connection between the battery and the electrical device is interrupted, and if the connection prohibition condition is not satisfied, the control device controls the external charging device so that the external charging is started and controls the connection / disconnection device so that the battery and the electrical device are electrically connected (Claim 1).

[0008] In the present invention, when a request for external charging is issued while the connection prohibition condition is not satisfied, the external charging device is controlled so that external charging is started, and the battery and the electrical device are electrically connected. Therefore, power can be appropriately supplied to the electrical device during external charging.

[0009] Moreover, in the present invention, when the SOC of the battery is low, the number of external charging failure times is equal to or more than the number of determination times, and an external charging related device (an off-vehicle power supply device or an external charging device of the vehicle) is malfunctioning and it is considered that power is not appropriately supplied from the off-vehicle power supply to the battery side, the electrical connection between the battery and the electrical device is interrupted. Therefore, it is possible to prevent power from being supplied from the battery to the electrical device in a state where the SOC of the battery is low and power is not supplied to the battery from the off-vehicle power supply, and it is possible to surely prevent the SOC of the battery from further decreasing due to the power supply to the electrical device, that is, to surely prevent the battery from being over-discharged.

[0010] As a configuration for determining that the external charging has failed, a configuration may be mentioned in which the control device determines that the external charging has failed when power is not supplied from the off-vehicle power supply to the battery even after a predetermined determination time has elapsed since the control device controls the external charging device so that the external charging is started (Claim 2).

[0011] In the above configuration, preferably, the electrical device includes a low-voltage battery having an output voltage lower than that of the battery and a DC / DC converter that steps down the power from the battery and charges the low-voltage battery, and the control device activates the DC / DC converter when a request for external charging is issued (Claim 3).

[0012] According to this configuration, the low-voltage battery can be charged during external charging, and when the SOC of the battery is low and the external charging related device is malfunctioning as described above, the power supply from the battery to the low-voltage battery via the DC / DC converter is stopped, so that over-discharge of the battery due to the power supply to the low-voltage battery can be prevented.

[0013] As the external charging device, a device including an AC external charging unit that has an AC / DC converter for converting an alternating current into a direct current and charges the battery with the output power from an external AC power source outside the vehicle can be mentioned (Claim 4).

[0014] Also, as the external charging device, a device including a DC external charging unit that charges the battery with the output power from a DC power source outside the vehicle can be mentioned (Claim 5).

[0015] In the above configuration, preferably, the battery is electrically connected to the external charging device via an electrical device circuit in which the electrical device is provided, and the connection / disconnection device disconnects / connects the electrical connection between the battery and the electrical device by disconnecting / connecting the electrical connection between the electrical device circuit and the battery. When the number of charging failures is 1 or more, the control device resets the number of charging failures to 0 when the SOC of the battery becomes equal to or higher than a predetermined second determination value that is higher than the determination value (Claim 6).

[0016] According to this configuration, when the SOC of the battery recovers and there is no risk of over-discharging the battery, the connection between the battery and the electrical device circuit, and thus the electrical connection between the battery and the external charging device, can be realized again. Therefore, charging of the battery by an external power source can be resumed. Accordingly, it is possible to ensure the opportunity to charge the battery by an external power source while preventing over-discharging of the battery.

Advantages of the Invention

[0017] As described above, according to the battery charging device for a vehicle of the present invention, over-discharging of the battery can be prevented.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

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Figure 4

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Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0019] (1) Overall Configuration of the Vehicle The battery charging device of the vehicle according to the embodiment of the present invention will be described. FIG. 1 is a diagram schematically showing the configuration of a vehicle 1 equipped with a battery charging device 100 according to the present embodiment. The vehicle 1 is, for example, a four-wheel automobile.

[0020] The vehicle 1 includes a high-voltage battery 2, an AC external charging device 40, a DC external charging device 50, and a plurality of high-voltage devices 90 that include a low-voltage battery 3 having an output voltage lower than that of the high-voltage battery 2 and are supplied with power from the high-voltage battery 2. The vehicle 1 also has a plurality of controllers that include a microprocessor or the like and control each part of the vehicle 1. Note that the high-voltage battery 2 corresponds to the "battery" in the claims, and the high-voltage devices 90 correspond to the "electrical devices" in the claims. Also, the AC external charging device 40 corresponds to the "AC external charging unit" in the claims, the DC external charging device 50 corresponds to the "DC external charging unit" in the claims, and the AC external charging device 40 and the DC external charging device 50 together correspond to the "external charging device" in the claims.

[0021] (Battery) In this embodiment, a Li battery (lithium battery) is mounted on the vehicle 1 as the high-voltage battery 2. For example, the high-voltage battery 2 includes a plurality of battery modules each composed of 12 battery cells connected in 2 parallel rows × 6 series rows, and these battery modules are connected in series. Also, in this embodiment, a lead battery is mounted on the vehicle 1 as the low-voltage battery 3. For example, the nominal voltage of the high-voltage battery 2 is 24V, and the nominal voltage of the low-voltage battery 3 is 12V.

[0022] The high-voltage battery 2 is provided with a battery current sensor SN1 that detects the battery current, which is the current flowing through the high-voltage battery 2, and a battery voltage sensor SN2 that detects the output voltage of the high-voltage battery 2.

[0023] (High-voltage equipment) In addition to the low-voltage battery 3, the vehicle 1 is provided with a motor 4, a generator 5, an inverter 6, a converter 7, a DC / DC converter 8, a PTC heater 9, and an electric compressor 10 as high-voltage equipment 90. These are provided on the same circuit. Hereinafter, the circuit on which these high-voltage equipment 90 are provided is appropriately referred to as the high-voltage circuit 30. This high-voltage circuit 30 corresponds to the "electrical equipment circuit" in the claims.

[0024] The high-voltage circuit 30 has a P-side high-voltage line 31a, which is a positive-side line connected to the positive electrode terminal 2a of the high-voltage battery 2, and an N-side high-voltage line 31b, which is a negative-side line connected to the negative electrode terminal 2b of the high-voltage battery 2. Hereinafter, the P-side high-voltage line 31a and the N-side high-voltage line 31b are appropriately collectively referred to as the high-voltage line 31.

[0025] The inverter 6, the converter 7, the DC / DC converter 8, the PTC heater 9, and the electric compressor 10 are each connected to the high-voltage line 31. The motor 4 is connected to the high-voltage line 31 via the inverter 6. The generator 5 is connected to the high-voltage line 31 via the converter 7.

[0026] The motor 4 rotates by receiving power supply from the high-voltage battery 2. The motor 4 is mounted on the vehicle 1 as a drive source of the vehicle 1, and the output of the motor 4 is transmitted to wheels (not shown) via the driving force transmission device 20.

[0027] The generator 5 is a power generation device for charging the high-voltage battery 2. The vehicle 1 of the present embodiment is a series hybrid vehicle, and the vehicle 1 is equipped with an engine 22 for driving the generator 5. That is, the generator 5 is rotationally driven by the engine 22 to generate electricity, and the electricity generated by the generator 5 is supplied to the high-voltage battery 2. The engine 22 is, for example, a rotary engine. Note that the generator 5 is also connected to the wheels via the driving force transmission device 20, and the vehicle 1 can regenerate the energy during deceleration.

[0028] The inverter 6 is a device that converts direct current into alternating current, and converts the direct current from the high-voltage battery 2 into alternating current and supplies it to the motor 4. The converter 7 is a device that converts alternating current into direct current, and converts the alternating current generated by the generator 5 into direct current and supplies it to the high-voltage battery 2.

[0029] The DC / DC converter 8 is a device that steps down the input power and outputs it, and steps down the output voltage of the high-voltage battery 2 and supplies it to the low-voltage battery 3. The DC / DC converter 8 is equipped with a microcomputer, and the control of the operation / stop, etc. of the DC / DC converter 8 is performed by this microcomputer. This microcomputer operates by receiving power from the low-voltage battery 3.

[0030] The PTC heater 9 and the electric compressor 10 constitute the air conditioning device 11 of the vehicle 1. Specifically, the PTC heater 9 is a device for heating the interior of the vehicle 1, and the electric compressor 10 is a device for cooling the interior of the vehicle 1. In the present embodiment, a cooling plate (not shown) for cooling the high-voltage battery 2 is provided, and the electric compressor 10 also cools this cooling plate.

[0031] The high-voltage circuit 30 and the high-voltage battery 2 are connected via a contactor. The contactor is an electromagnetic switch including an electromagnet, and disconnects and connects the electrical connection between two contacts according to the supplied power. When the contactor is closed, the two contacts are electrically connected and energized, and when the contactor is opened, the two contacts are electrically disconnected and de-energized.

[0032] Specifically, the vehicle 1 is provided with a P-side main contactor 71 in which the positive terminal 2a of the high-voltage battery 2 (specifically, the positive-side battery line 2d connected to the positive terminal 2a) and the P-side high-voltage line 31a are connected to the two contacts respectively, and the P-side main contactor 71 disconnects and connects the electrical connection between the positive terminal 2a of the high-voltage battery 2 and the P-side high-voltage line 31a. Further, the vehicle 1 is provided with an N-side main contactor 72 in which the negative terminal 2b of the high-voltage battery 2 (specifically, the negative-side battery line 2e connected to the negative terminal 2b) and the N-side high-voltage line 31b are connected to the two contacts respectively, and the N-side main contactor 72 disconnects and connects the electrical connection between the negative terminal 2b of the high-voltage battery 2 and the N-side high-voltage line 31b. And, the electrical connection between the high-voltage line 31, and thus the high-voltage circuit 30 and the high-voltage device 90 and the high-voltage battery 2, is disconnected and connected by these two P-side main contactors 71 and N-side main contactors 72. These P-side main contactors 71 and N-side main contactors 72 correspond to the "disconnecting and connecting device" in the claims.

[0033] In addition, in this embodiment, a pre-charge contactor 73 disposed in parallel with the N-side main contactor 72 is provided as a contactor, and the electrical connection between the negative terminal 2b of the high-voltage battery 2 and the N-side high-voltage line 31b is also disconnected and connected by the pre-charge contactor 73. However, a resistor 74 is disposed in series with the line where the pre-charge contactor 73 is provided, and the electrical resistance between the terminal of the high-voltage battery 2 via the pre-charge contactor 73 and the high-voltage line 31 is made larger than the electrical resistance between the terminal of the high-voltage battery 2 via the pre-charge contactor 73 and the N-side main contactor 72 and the high-voltage line 31.

[0034] (AC external charging device 40) The AC external charging device 40 is a device for supplying power from an external AC power source outside the vehicle to the high-voltage battery 2 to charge the high-voltage battery 2. The AC external charging device 40 includes an OBC (On Board Charger) 41, an AC charging inlet 42, and a pair of OBC contactors 44a and 44b.

[0035] The OBC 41 is a device for converting the alternating current supplied from outside the vehicle into a current that can appropriately charge the high-voltage battery 2, and has an AC / DC converter 43 that is a device for converting the alternating current into a direct current. The OBC 41 operates by receiving power from the low-voltage battery 3.

[0036] The AC charging inlet 42 is a device for electrically connecting a cable connected to an external AC power source 300 outside the vehicle and the OBC 41. The AC charging inlet 42 is electrically connected to the OBC 41, and is configured such that a connector (hereinafter, appropriately referred to as an AC connector) provided at the end of the above cable is inserted and fitted thereto.

[0037] The OBC contacts 44a and 44b are contacts that electrically connect and disconnect the OBC 41 and the high-voltage line 31 (high-voltage circuit 30). Two contacts of one of the OBC contacts 44a (hereinafter referred to as the P-side OBC contact 44a) are connected to the positive-side line 43a of the OBC 41 and the P-side high-voltage line 31a, respectively, and the P-side OBC contact 44a disconnects the electrical connection between the positive-side line 43a of the OBC 41 and the P-side high-voltage line 31a. Two contacts of the other OBC contact 44b (hereinafter referred to as the N-side OBC contact 44b) are connected to the negative-side line 43b of the OBC 41 and the N-side high-voltage line 31b, respectively, and the N-side OBC contact 44b connects and disconnects the electrical connection between the negative-side line 43b of the OBC 41 and the N-side high-voltage line 31b.

[0038] (DC external charging device 50) The DC external charging device 50 is a device for supplying power from an external DC power source outside the vehicle to the high-voltage battery 2 to charge the high-voltage battery 2. The DC external charging device 50 includes a DC charging inlet 52 and a pair of QBC contacts 51a and 51b.

[0039] The DC charging inlet 52 is a device for electrically connecting a cable connected to an external DC power source 301 outside the vehicle and the high-voltage line 31. The DC charging inlet 52 is configured such that a connector (hereinafter, appropriately referred to as a DC connector) provided at the end of the above cable is inserted and fitted thereto.

[0040] The QBC contacts 51a and 51b are contacts that electrically connect and disconnect the DC charging inlet 52 and the high-voltage line 31. Two contacts of one of the QBC contacts 51a (hereinafter referred to as the P-side QBC contact 51a) are connected to the positive-side line 52a of the DC charging inlet 52 and the P-side high-voltage line 31a, respectively. The P-side QBC contact 51a electrically connects and disconnects the positive-side line 52a of the DC charging inlet 52 and the P-side high-voltage line 31a. Two contacts of the other QBC contact 51b (hereinafter referred to as the N-side QBC contact 51b) are connected to the negative-side line 52b of the DC charging inlet 52 and the N-side high-voltage line 31b, respectively. The N-side QBC contact 51b electrically connects and disconnects the negative-side line 52b of the DC charging inlet 52 and the N-side high-voltage line 31b.

[0041] (Controller) Figure 2 is a block diagram showing the relationship between the controllers mounted on the vehicle 1. The vehicle 1 is equipped with controllers such as a C-BCM (Center-Body Control Module) 200, a PCM (Power Control Module) 201, an ECM (Engine Control Module) 202, a DMCM (Driver Moor Control Module) 203, an SGCM (Starter Generator Control Module) 204, a BCCM (Battery Charger Control Module) 205, a BECM (Battery Energy Control Module) 206, and an ESU (Electric Supply Unit) 207. These controllers 200 to 207 are connected to the low-voltage battery 3 and operate by receiving power from the low-voltage battery 3.

[0042] Each of the controllers 200 to 207 mainly performs the following controls. The C-BCM 200 controls doors, windows, etc. The PCM 201 controls the drive system devices of the vehicle 1. The ECM 202 controls the engine 22. The DMCM 203 controls the inverter 6. The SGCM 204 controls the converter 7. The BCCM 205 controls the OBC 41. The BECM 206 controls the high-voltage battery 2. The ESU 207 controls the air conditioning device 11. These controllers 200 to 207 exchange signals with each other. For example, these controllers 200 to 207 perform CAN (Controller Area Network) communication with each other.

[0043] Here, the HMI device 208 shown in FIG. 2 is a device that displays various information and includes a display and the like. Note that HMI is an abbreviation for Human Machine Interface.

[0044] (External charging control) Next, external charging control related to charging the high-voltage battery 2 with an external power source outside the vehicle will be described. FIG. 3 is a block diagram showing the control configuration of the external charging control. The external charging control is mainly implemented by the PCM 201. The PCM 201 corresponds to the "control device" in the claims.

[0045] A signal is input to the PCM 201 from the AC charging inlet 42 via the BCCM 205. Specifically, the AC charging inlet 42 is configured to output a predetermined signal (hereinafter, appropriately referred to as the AC connector mating signal) to the BCCM 205 when the AC connector is mated and the external charging based on the external AC power source 300 becomes possible. When this AC connector mating signal is input from the AC charging inlet 42, the BCCM 205 transmits it to the PCM 201.

[0046] Also, a signal is input to the PCM 201 from the DC charging inlet 52. Specifically, a predetermined switch is provided in the DC power supply device 301. When the switch in the DC power supply device 301 is turned on in a state where the DC connector and the DC charging inlet 52 are fitted, the DC power supply device 301 outputs power toward the high-voltage battery 2. When the switch is turned on in a state where the DC connector is fitted to the DC charging inlet 52 and external charging by the DC power supply device 301 becomes possible, the DC charging inlet 52 transmits a predetermined signal (hereinafter, appropriately referred to as a DC charging switch ON signal) to the PCM 201.

[0047] Also, detection signals such as the battery current sensor SN1 and the battery voltage sensor SN2 are input to the PCM 201 via the BECM 206.

[0048] The PCM 201 performs various calculations and determinations based on the above signals and issues commands to each device of the vehicle 1. During external charging control, the PCM 201 issues commands to at least the P-side main contactor 71, N-side main contactor 72, pre-charge contactor 73, OBC contactors 44a, 44b, QBC contactors 51a, 51b, DC / DC converter 8, and each controller (DMCM 203, SGCM 204, BCCM 205, BECM 206, ESU 207).

[0049] FIG. 4 is a flowchart showing the procedure of external charging control. The details of the external charging control will be described with reference to FIG. 4. Here, the external charging control is configured to be performed while the vehicle is stopped, and the flowchart of FIG. 4 is executed while the vehicle is stopped. Also, after the vehicle stops, each contactor (main contactors 71, 72, pre-charge contactor 73, OBC contactors 44a, 44b, QBC contactors 51a, 51b) is turned off (opened) after a predetermined time, and the flowchart of FIG. 4 starts with each contactor in the OFF state.

[0050] First, it is determined whether an external charging request has been issued (step S1). Then, only when an external charging request has been issued (only when the determination in step S1 is YES), the processing after step S2 is performed. Specifically, when an AC connector mating signal is transmitted from the AC charging inlet 42 to the BCCM205, or when a DC charging switch ON signal is transmitted from the DC charging inlet 52 to the PCM201, the determination in step S1 becomes YES.

[0051] When the AC connector mating signal or the DC charging switch ON signal is transmitted and the determination in step S1 becomes YES, each controller is activated (step S2). That is, the power supply from the low-voltage battery 3 to each controller is started. Specifically, when the AC connector mating signal is transmitted to the BCCM205, first, the BCCM205 is activated, and the PCM201 is activated by the BCCM205. Thereafter, the DMCM203, SGCM204, BECM206, and ESU207 are activated by the PCM201. Also, when the DC charging switch ON signal is transmitted to the PCM201, the PCM201 is activated, and the DMCM203, SGCM204, BCCM205, BECM206, and ESU207 are activated by the PCM201. When the AC connector mating signal is transmitted to the BCCM205, as described above, the AC connector mating signal is also sent from the BCCM205 to the PCM201. Also, at this time, power is supplied from the low-voltage battery 3 to the OBC41, and this is also activated.

[0052] The processing after step S2 is performed by the PCM201.

[0053] First, when the PCM201 is activated in response to an external charging request, it activates the DC / DC converter 8 together with the activation of the DMCM203, etc. (step S3). Specifically, in response to a command from the PCM201, power supply from the low-voltage battery 3 to the DC / DC converter 8 (specifically, the microcomputer provided in the DC / DC converter 8) is started, and the DC / DC converter 8 is set to an operable state. That is, in this embodiment, during external charging, in addition to the high-voltage battery 2, the low-voltage battery 3 is also charged. When an external charging request is issued, the DC / DC converter 8 is in an operable state and can step down the power supply received and supply it to the low-voltage battery 3. At the time of step S3, the high-voltage circuit 30 is not electrically connected to either the high-voltage battery 2 or the external charging devices 40 and 50. Therefore, at the time of step S3, since there is no power supply to the DC / DC converter 8, the DC / DC converter 8 does not operate.

[0054] Next, the PCM201 determines whether the battery SOC, which is the SOC (State Of Charge) of the high-voltage battery 2, is equal to or higher than a predetermined second determination SOC (step S4). The PCM201 calculates the battery SOC based on information related to the high-voltage battery 2 sent from the battery current sensor SN1, the battery voltage sensor SN2, etc. In step S4, the PCM201 compares this calculated value with the second determination SOC. The second determination SOC is preset to a value higher than the first determination SOC, which will be described later, and is stored in the PCM201. The second determination SOC corresponds to the "second determination value" in the claims.

[0055] If the battery SOC is less than the second determination SOC and the determination in step S4 is NO, the PCM201 proceeds to step S6. On the other hand, if the battery SOC is equal to or higher than the second determination SOC and the determination in step S4 is YES, the PCM201 proceeds to step S5 and resets the charging failure count to 0. After step S5, it proceeds to step S6. The charging failure count is the number of times the PCM201 determines that external charging has failed. The determination procedure for whether external charging has failed will be described later.

[0056] In step S6, the PCM 201 determines whether or not a connection prohibition condition that the battery SOC is less than a predetermined first determination SOC and the number of charge failure times is equal to or more than a predetermined determination number is satisfied. The first determination SOC and the determination number are preset and stored in the PCM 201. In this embodiment, the maximum value of the discharge amount of the high-voltage battery 2 caused by one external charge failure is calculated by experiments or the like, and the number of times the maximum value of the discharge can be tolerated is set as the determination number. For example, the determination number is set to 3 times. Further, the first determination SOC is set to 2%, and the second determination SOC is set to 5% which is higher than 2%. The first determination SOC corresponds to the "determination value" in the claims.

[0057] When the above connection prohibition condition is not satisfied and the determination in step S6 is NO, that is, when the battery SOC is equal to or more than the first determination SOC or the number of charge failure times has not reached the determination number, the PCM 201 proceeds to step S7. Then, in step S7, the PCM 201 starts external charging. Specifically, the PCM 201 switches the main contacts 71 and 72 from OFF to ON (closed state), and also switches the OBC contacts 44a and 44b or the QBC contacts 51a and 51b from OFF to ON. Further, when an AC connector mating signal is input, after turning on the main contacts 71 and 72, the PCM 201 outputs a predetermined signal to the AC power supply device 300 to switch the state of the power supply device 300 to a state capable of power output.

[0058] Specifically, when an AC connector mating signal is input, in step S7, the PCM 201 first switches the pre-charge contactor 73, the P-side main contactor 71, and each OBC contactor 44a, 44b to ON, and then switches the N-side main contactor 72 to ON and returns the pre-charge contactor 73 to OFF. In this way, when the main contactors 71, 72 are turned ON, the high-voltage battery 2 and the high-voltage circuit 30 are electrically connected. Also, when the OBC contactors 44a, 44b are turned ON, the high-voltage circuit 30 and the OBC 41 are electrically connected. At the time of step S7, the AC charging inlet 42 and the AC connector are mated, and the AC charging inlet and the OBC 41 are electrically connected to the external AC power supply 300. Thus, by implementing step S7, the AC power supply 300 and the high-voltage circuit 30 are electrically connected via the AC charging inlet 42 and the OBC 41, the high-voltage circuit 30 and the high-voltage battery 2 are electrically connected, and the AC power supply 300 and the high-voltage battery 2 are electrically connected via the AC charging inlet 42, the OBC 41, and the high-voltage circuit 30. Here, the control to turn on the OBC contactors 44a, 44b corresponds to "controlling the external charging device so that external charging is started" in the claims.

[0059] Also, when a DC charging switch ON signal is input, at step S7, the PCM 201 first switches the pre-charge contactor 73, the P-side main contactor 71, and each QBC contactor 51a, 51b to ON, and then switches the N-side main contactor 72 to ON and returns the pre-charge contactor 73 to OFF. Similarly to the above, also in this case, when the main contactors 71, 72 are turned ON, the high-voltage battery 2 and the high-voltage circuit 30 are electrically connected. Also, when the QBC contactors 51a, 51a are turned ON, the high-voltage circuit 30 and the DC charging inlet 52 are electrically connected. At the time of step S7, the DC charging inlet 52 and the DC connector are fitted, and the DC charging inlet 52 and the external DC power supply 301 outside the vehicle are electrically connected. From this, by implementing step S7, the DC power supply 301 and the high-voltage circuit 30 are electrically connected via the DC charging inlet 52, the high-voltage circuit 30 and the high-voltage battery 2 are electrically connected, and the DC power supply 301 and the high-voltage battery 2 are electrically connected via the DC charging inlet 52 and the high-voltage circuit 30. Here, the control for turning ON the QBC contactors 51a, 51b corresponds to "controlling the external charging device so that external charging is started" in the claims.

[0060] Next to step S7, the PCM 201 determines whether or not the charging-side battery current, that is, the current flowing into the high-voltage battery 2, has increased until a predetermined determination time has elapsed after implementing step S7 (step S8). Specifically, the PCM 201 determines whether or not the battery current has increased from the value before the implementation of step S7, that is, the value before each contactor 71, 72, 44a, 44b (51a, 51b) is switched to ON. This determination is implemented based on the detected value of the battery current sensor SN1. Note that the above determination time is set and stored in advance. For example, the determination time is set to about 5 minutes.

[0061] And if the determination in step S8 is NO, that is, if the charging-side battery current does not increase between the execution of step S5 and the elapse of the determination time, the PCM 201 proceeds to step S10 and determines that the external charging has failed. Then, the number of charging failure times is incremented (that is, 1 is added to the stored number of charging failure times).

[0062] That is, as described above, by executing step S7, the high-voltage battery 2 and the external power source (AC power source 300 or DC power source 301) are electrically connected. Therefore, if the external charging-related devices (devices related to external charging, namely, AC power source 300, DC power source 301, AC external charging device 40, DC external charging device 50) are not faulty, power is supplied from the external power sources 300, 301 to the high-voltage battery 2, and the charging-side current flowing through the high-voltage battery 2 increases. On the contrary, if the external charging-related devices are faulty and external charging cannot be properly performed, that is, if external charging fails, as a result, power is not supplied from the external power sources 300, 301 to the high-voltage battery 2, and the charging-side current flowing through the high-voltage battery 2 does not increase. From this, the PCM 201 determines whether external charging has failed based on whether the battery current has increased after executing step S7 as described above.

[0063] After step S10, it proceeds to step S11. The PCM 201 switches the main contactor from ON to OFF and switches the OBC contactors 44a, 44b or QBC contactors 51a, 51b that are ON to OFF to end the process (step S11). When step S11 is executed and each of the contactors 71, 72, 44a, 44b (51a, 51b) is turned OFF, all the electrical connections between the high-voltage battery 2, the high-voltage circuit 30, and the power supply device 300 (301) are interrupted.

[0064] On the one hand, when the determination in step S8 is YES, that is, when the charging-side battery current increases between the execution of step S5 and the elapse of the determination time and external charging is being properly performed, the PCM 201 maintains the main contacts 71, 72 and the OBC contacts 44a, 44b or the QBC contacts 51a, 51b in the ON state and proceeds to step S9. In step S9, the PCM 201 determines whether an external charging stop request has been issued. Specifically, the PCM 201 determines that an external charging stop request for stopping external charging has been issued when the input of the DC charging switch ON signal has disappeared (the switch of the DC power supply device 301 has been turned OFF), the input of the AC connector mating signal has disappeared (the AC connector has been removed from the AC charging inlet 42), the high-voltage battery 2 is fully charged, or the preset external charging time has elapsed.

[0065] When the external charging stop request has not been issued and the determination in step S9 is NO, the PCM 201 maintains the contacts 71, 72, 44a, 44b (51a, 51b) in the ON state. When an external charging stop request is issued (when the determination in step S9 becomes YES), it proceeds to step S11, switches the main contacts from ON to OFF, and switches the OBC contacts 44a, 44b or the QBC contacts 51a, 51b that are in the ON state to OFF, and ends the process.

[0066] Return to step S6. If the determination in step S6 is YES, that is, when the connection prohibition condition that the battery SOC is less than the first determination SOC and the number of charging failure times is equal to or greater than the determination number is satisfied, the PCM201 proceeds to step S12. In step S12, the PCM201 maintains the contactor in the OFF state. Specifically, the PCM201 maintains all of the main contactors 71 and 72, the pre-charge contactor 73, the OBC contactors 44a and 44b, and the QBC contactors 51a and 51b in the OFF state. As a result, all of the electrical connections between the high-voltage battery 2, the high-voltage circuit 30, and the power supply device 300 (301) are maintained in a disconnected state. Further, after step S12, the PCM201 proceeds to step S13, causes the HMI device 208 to perform a display or the like notifying an abnormality, and notifies the occupant that external charging is impossible, and ends the process.

[0067] (Operation, etc.) FIGS. 5 to 7 are time charts showing the time changes of the respective parameters when the above-described external charging control is performed. FIGS. 5 to 7 illustrate a case where the external charging control is executed as the AC connector mating signal is input to the BCCM206. FIG. 5 is a time chart when the connection prohibition condition is not satisfied and the AC power supply device 300 is not faulty. FIG. 6 is a time chart when the connection prohibition condition is not satisfied and the AC power supply device 300 is faulty. FIG. 7 is a time chart when the connection prohibition condition is satisfied. In FIGS. 5 to 7, in order from the top, there are shown graphs of the external charging request flag, the activation state of the BCCM205, the activation states of the respective controllers (PCM201, DMCM203, SGCM204, BECM206, ESU207) and the DC / DC converter 8, the ON / OFF states of the main contactors 71 and 72, the ON / OFF states of the OBC contactors 44a and 44b, the battery current (the current flowing through the high-voltage battery 2), the charging failure flag, and the battery SOC (the SOC of the high-voltage battery 2). Note that the graphs of the battery current and the battery SOC in FIG. 7 also show the graph of FIG. 6 by a chain line. The above-described external charging request flag is a flag that becomes 1 while a request for external charging is issued and becomes 0 otherwise.

[0068] In the example of FIG. 5, an external charging request is issued at time t1, and the external charging request flag changes from 0 to 1. FIG. 5 is an example when an AC connector mating signal is input to BCCM205. In this case, as described above, at time t2 after time t1, first, BCCM206 is activated and switched from OFF to ON. Then, at time t3 after that, each of the controllers 201, 203, 204, 206, 207, and the DC / DC converter 8 are activated and switched from OFF to ON. Also, at time t4 after time t3, the main contacts 71, 72 and the OBC contacts 44a, 44b are switched from OFF to ON. Note that, as described above, in the case of external charging associated with the AC connector mating signal, a signal for permitting the power output from the PCM201 to the AC power supply device 300 is also output.

[0069] FIG. 8 is a diagram schematically showing the flow of electricity after time t4 in the example of FIG. 5. Note that in FIG. 8, the illustration of some devices is omitted. When the connection prohibition condition is not satisfied and the AC power supply device 300 is not faulty and the main contacts 71, 72 and the OBC contacts 44a, 44b are turned ON, as shown by arrow Y1, electricity is supplied from the AC power supply device 300 to the AC external charging device 40. As shown by arrow Y2, electricity is supplied from the AC external charging device 40 to the high-voltage circuit 30. Then, as shown by arrow Y3, electricity flows from the high-voltage circuit 30 to the high-voltage battery 2. As a result, in the example of FIG. 5, after time t4 when each of the contacts 71, 72, 41a, 44b is turned ON, the charging-side battery current increases. Also, the battery SOC also increases after time t4.

[0070] Here, the DC / DC converter 8 is activated at time t4. From this time on, after time t4, as shown by the arrow Y4 in FIG. 8, electricity is also supplied from the AC power supply device 300 to the DC / DC converter 8 via the high-voltage circuit 30. Then, the output power of the AC power supply device 300 is stepped down by the DC / DC converter 8 and supplied to the low-voltage battery 3. Also, as shown by the arrow Y6 in FIG. 5, after time t4, the output power of the AC power supply device 300 is also supplied to the PTC heater 9 and the electric compressor 10 via the high-voltage circuit 30. Specifically, when a request to operate the PTC heater 9 or the electric compressor 10 is issued, the power required for operation is supplied. On the other hand, when no request to operate is issued, standby power is supplied to these devices.

[0071] Also in the example of FIG. 6, when an external charging request is issued at time t1 and the external charging request flag changes from 0 to 1, the BCCM 206 is switched to ON at time t2. Also in the example of FIG. 6, along with the non-establishment of the connection prohibition condition, at time t3, each of the controllers 201, 203, 204, 206, 207 and the DC / DC converter 8 is switched to ON, and at time t4, the main contacts 71, 72 and the OBC contacts 44a, 44b are switched to ON.

[0072] However, when the AC power supply device 300 is faulty, the flow of electricity after time t4 is as shown in FIG. 9. That is, when the AC power supply device 300 is faulty, even if the OBC contacts 44a, 44b are turned ON, no power is supplied from the AC power supply device 300 to the AC external charging device 40. Therefore, in this case, when the main contacts 71, 72 are turned ON and the high-voltage battery 2 and the high-voltage circuit 30 are electrically connected, as shown by the arrow Y11, electricity flows from the high-voltage battery 2 to the high-voltage circuit 30. Then, the output power of the high-voltage battery 2 flowing through the high-voltage circuit 30 is supplied to the low-voltage battery 3 via the DC / DC converter 8 as shown by the arrows Y4, Y5. Also, the output power of the high-voltage battery 2 is supplied to the PTC heater 9 and the electric compressor 10 as shown by the arrow Y6.

[0073] Therefore, when the connection prohibition condition is not satisfied and the AC power supply device 300 is malfunctioning, as shown in FIG. 6, after the time t4 when each of the contactors 71, 72, 41a, and 44b is turned ON, discharge is performed from the high-voltage battery 2, the battery current on the discharge side of the high-voltage battery 2 increases, and the battery SOC decreases. Then, in this case, since there is no increase in the battery current on the charging side from the time t4 until the time t5 after a determination time longer than this, at the time t5, each of the contactors 71, 72, 41a, and 44b is switched to OFF. Also, at the time t5, the number of charging failure times is incremented. When each of the contactors 71, 72, 41a, and 44b is switched to OFF, the electrical connection between the high-voltage battery 2 and the high-voltage circuit 30 is interrupted. Therefore, after the time t5, the battery current becomes 0, and the decrease in the battery SOC stops at the time t5.

[0074] Also, in the example of FIG. 7, when an external charging request is issued at the time t1 and the external charging request flag changes from 0 to 1, the BCCM 206 is switched to ON at the time t2. Also, at the time t3, each of the controllers 201, 203, 204, 206, 207, and the DC / DC converter 8 is switched to ON. However, in the example of FIG. 7, the connection prohibition condition is satisfied. Therefore, in the example of FIG. 7, even after the time t3, the main contactors 71, 72 and the OBC contactors 44a, 44b are maintained OFF. Therefore, even after the time t3, the electrical connection between the high-voltage battery 2 and the high-voltage circuit 30 is maintained in an interrupted state, and the power supply from the high-voltage battery 2 to the low-voltage battery 3 via the DC / DC converter 8 and the power supply from the high-voltage battery 2 to the PTC heater 9 and the electric compressor 10 are continuously stopped. Therefore, in the example of FIG. 7, the battery current is maintained at 0 even after the time t3, and the decrease in the battery SOC is avoided. That is, an increase in the battery current on the discharge side and a decrease in the battery SOC as in the example of FIG. 6 shown by the dashed line are avoided.

[0075] As described above, in the above-described embodiment, when an external charging request is issued, as long as the connection prohibition condition is not satisfied (when the determination in step S6 is NO), the main contacts 71 and 72 and the OBC contacts 44a and 44b (QBC contacts 51a and 51b) are switched to ON (step S7 is executed), and the external power source 300 (301) outside the vehicle, the high-voltage circuit 30, and the high-voltage battery 2 are electrically connected. Therefore, while supplying power from the external power source 300 (301) outside the vehicle to the high-voltage battery 2 to charge the high-voltage battery 2, power can also be supplied to the high-voltage device 90 provided in the high-voltage circuit 30.

[0076] In particular, in the above-described embodiment, the DC / DC converter 8 electrically connected to the low-voltage battery 3 is provided in the high-voltage circuit 30, and while charging the high-voltage battery 2, power can also be supplied to the low-voltage battery 3 via the DC / DC converter 8 to charge it. Also, since power can be supplied to the PTC heater 9 and the electric compressor 10 provided in the high-voltage circuit 30, the air conditioning device can be appropriately operated while charging the high-voltage battery 2.

[0077] However, simply electrically connecting the high-voltage battery 2 and the high-voltage circuit 30 when an external charging request is issued only causes power to be supplied from the high-voltage battery 2 to the high-voltage circuit 30 and the high-voltage device 90 provided therein when the external power supply device 300 (301) fails, as shown in FIG. 9. As a result, as shown by the solid line in FIG. 6 and the chain line in FIG. 7, the battery SOC decreases. Note that when the external charging devices 40 and 50 fail, power is not supplied from the external power source 300 (301) to the high-voltage battery 2, so the battery SOC decreases.

[0078] In contrast, in the above embodiment, when the connection prohibition condition is satisfied, that is, when the battery SOC is less than the first determination SOC, and the number of charging failures is equal to or more than the determination number and there is a high possibility that the external power supply device 300(301) or the external charging devices 40 and 50 outside the vehicle are faulty (when the determination in step S6 is NO), all of the main contacts 71 and 72, the pre-charge contact 73, the OBC contacts 44a and 44b, and the QBC contacts 51a and 51b are turned OFF, and the electrical connections between the external power supply 300(301) outside the vehicle, the high-voltage circuit 30, and the high-voltage battery 2 are maintained in a disconnected state. Therefore, it is possible to reliably prevent the high-voltage battery 2 from being over-discharged due to a further decrease in the battery SOC from the first determination SOC.

[0079] In addition, when the SOC of the battery, that is, the SOC of the high-voltage battery 2, becomes excessively low, it becomes difficult to charge the low-voltage battery 3 with the high-voltage battery 2, and thus the SOC of the low-voltage battery 3 also decreases. As described above, each controller operates by receiving power from the low-voltage battery 3. Therefore, when the SOC of the high-voltage battery 2 becomes excessively low, there is a risk that the SOC of the low-voltage battery 3 will decrease and, as a result, the controllers will not be able to start. In contrast, in the above embodiment, since an excessive decrease in the battery SOC is prevented, it is possible to prevent a decrease in the SOC of the low-voltage battery 3 and to prevent the controllers from becoming inoperable.

[0080] Here, even if external charging has failed in the past, if the battery SOC has recovered and become high, even if external charging fails again next time, the possibility of over-discharging of the high-voltage battery 2 is small. On the other hand, in the above embodiment, when the battery SOC becomes equal to or higher than a second determination SOC that is higher than the first determination SOC (when the determination in step S4 becomes YES), the charging failure count is reset to 0. And thereby, when the connection prohibition condition is not satisfied, as an external charging request is issued, the main contacts 71, 72 and the OBC contacts 44a, 44b (QBC contacts 51a, 51b) are turned ON, and charging of the high-voltage battery 2 by the external power supply device 300 (301) outside the vehicle is attempted. Therefore, while preventing over-discharging of the high-voltage battery 2, it is possible to secure an opportunity to charge the high-voltage battery 2 by the external power supply device 300 (301) outside the vehicle.

[0081] Also, in the above embodiment, after turning ON the OBC contacts 44a, 44b (QBC contacts 51a, 51b), that is, after controlling the external charging devices 40, 50 so that external charging is started, if the current on the charging side of the battery does not increase even after the determination time has elapsed and power is not supplied from the external power supplies 300, 301 outside the vehicle to the high-voltage battery 2, it is determined that external charging has failed. Therefore, it is possible to determine whether external charging has failed with a simple configuration. In particular, when the external power supplies 300, 301 outside the vehicle are malfunctioning, it is difficult for the vehicle side to detect this malfunction. On the other hand, according to this configuration, it is possible to determine the failure of external charging due to the malfunction of the external power supplies 300, 301 outside the vehicle.

[0082] (Modification example) The high-voltage device 90 to which power is supplied from the high-voltage battery 2 is not limited to the above. Also, the specific determination procedure for whether external charging has failed is not limited to the above. Also, in the above embodiment, the case where the battery charging device 100 is mounted on a series hybrid vehicle has been described, but the type of vehicle on which the battery charging device 100 is mounted is not limited to this.

Description of reference numerals

[0083] 2 High-voltage battery (battery) 3 Low-voltage battery 8 DC / DC converter 30 High-voltage circuit (electrical equipment circuit) 40 AC external charging device (AC external charging unit, external charging device) 50 DC external charging device (DC external charging unit, external charging device) 71 P-side main contactor (disconnecting and connecting device) 72 N-side main contactor (disconnecting and connecting device) 90 High-voltage equipment (electrical equipment) 201 PCM (control device) 300 Power source outside the vehicle, AC power source, AC power supply device 301 Power source outside the vehicle, DC power source, DC power supply device

Claims

1. In a battery charging device for a vehicle equipped with a battery and an external charging device capable of performing external charging for charging the battery with power supplied from an external power source outside the vehicle, an electrical device supplied with power from the battery; a disconnecting and connecting device capable of disconnecting and connecting the electrical connection between the battery and the electrical device; and a control device for controlling the disconnecting and connecting device, wherein when a request for the external charging is issued, if a connection prohibition condition that the state of charge (SOC) of the battery is less than a predetermined determination value and the number of charging failures, which is the number of times the external charging has failed, is equal to or more than a predetermined determination number is satisfied, the control device controls the disconnecting and connecting device so that the electrical connection between the battery and the electrical device is disconnected, and if the connection prohibition condition is not satisfied, the control device controls the external charging device so that the external charging is started and controls the disconnecting and connecting device so that the battery and the electrical device are electrically connected. A battery charging device for a vehicle, characterized by the above.

2. In the battery charging device for a vehicle according to Claim 1, when the control device controls the external charging device so that the external charging is started and power is not supplied from the external power source outside the vehicle to the battery even after a predetermined determination time has elapsed, the control device determines that the external charging has failed. A battery charging device for a vehicle, characterized by the above.

3. In the battery charging device for a vehicle according to Claim 1 or 2, the electrical device includes a low-voltage battery having an output voltage lower than that of the battery and a DC / DC converter that steps down the power from the battery to charge the low-voltage battery, and when a request for the external charging is issued, the control device activates the DC / DC converter. A battery charging device for a vehicle, characterized by the above.

4. In the battery charging device for a vehicle according to any one of Claims 1 to 3, the external charging device includes an AC external charging unit that has an AC / DC converter for converting an alternating current into a direct current and charges the battery with the output power from an AC power source outside the vehicle. A battery charging device for a vehicle, characterized by the above.

5. In the battery charging device for a vehicle according to any one of Claims 1 to 4, the external charging device includes a DC external charging unit that charges the battery with the output power from a DC power source outside the vehicle. A battery charging device for a vehicle, characterized by the above.

6. In the battery charging device for a vehicle according to any one of claims 1 to 5, the battery is electrically connected to the external charging device via an electrical equipment circuit provided with the electrical equipment, the connection / disconnection device disconnects / connects the electrical connection between the battery and the electrical equipment by disconnecting / connecting the electrical connection between the electrical equipment circuit and the battery, the control device resets the number of charging failures to 0 when the SOC of the battery becomes equal to or higher than a predetermined second determination value that is higher than the determination value when the number of charging failures is 1 or more. A battery charging device for a vehicle, characterized by the above.

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