JP6724811B2 - Charging system - Google Patents

Description

The present disclosure relates to a charging system, and more particularly to a charging system that charges a power storage device by a DC charging facility that supplies DC power.

Japanese Patent Laying-Open No. 2016-174468 (Patent Document 1) discloses a power supply system capable of charging a vehicle-mounted power storage device by a DC charging facility outside the vehicle (hereinafter also referred to as “DC (Direct Current) charging facility”). In this power supply system, the charging relay of the vehicle is turned off (open state) after the charging of the power storage device by the DC charging facility is completed, and the voltage between the charging relay and the power receiving inlet is detected by the voltage sensor. .. When a voltage above the judgment value is detected by the voltage sensor, turning off the system main relay creates a state in which no voltage is applied to the voltage sensor, and whether or not the voltage sensor detects a voltage above the judgment value. The voltage sensor check for checking whether or not is executed. As a result, it is specified whether the charging relay is closed and stuck or the voltage sensor is broken (see Patent Document 1).

JP, 2016-174468, A

The technique described in Patent Document 1 is useful in that it is possible to perform a failure diagnosis by distinguishing between the stuck and stuck charging relay and the failure of the voltage sensor after the charging of the power storage device by the DC charging facility is completed, but the power storage device by the DC charging facility is useful. Patent Document 1 does not discuss a method for diagnosing open sticking of a charging relay (switch) at the start of charging. In the power supply system described in Patent Document 1, when the detection value of the voltage sensor indicates 0 V when the charging relay is turned on (closed state), the charging relay is stuck open or the voltage sensor fails. It is not possible to identify what is happening.

The present disclosure has been made to solve such a problem, and an object thereof is to provide a charging system that charges a power storage device by a DC charging facility that supplies direct-current power, and a switch is provided at the start of charging the power storage device. It is possible to determine whether the sticking is open or the voltage sensor is out of order.

The charging system of the present disclosure includes a power storage device, a power receiving unit, a switch, a voltage sensor, and a control device. The power storage device is charged by a DC charging facility that supplies DC power. The power receiving unit is configured to receive DC power from the DC charging facility and output the DC power to the power storage device. The switch is provided in an electric path between the power receiving unit and the power storage device. The voltage sensor detects the voltage of the electric path between the switch and the DC charging facility. The controller is configured to determine switch and voltage sensor failures. When the DC charging equipment is connected to the power receiving unit, the DC charging equipment is configured to output a voltage and perform insulation diagnosis of the DC charging equipment before the switch is closed. When the detection value of the voltage sensor indicates zero during the execution of the insulation diagnosis of the DC charging equipment, the control device determines that the voltage sensor is out of order. The control device, when the detection value of the voltage sensor shows non-zero during the insulation diagnosis of the DC charging equipment, when the detection value of the voltage sensor shows zero after the insulation diagnosis is completed and the switch is closed. Determines that the switch is stuck open.

With the above configuration, when charging of the power storage device by the DC charging facility is started, it can be determined whether the switch is stuck open or the voltage sensor is out of order. If the failure diagnosis of the switch and the voltage sensor is executed after the charging of the power storage device by the DC charging facility is started, a process of temporarily stopping the output of the DC charging facility or once opening the switch is required. However, according to the charging system of the present disclosure, at the start of charging of the power storage device by the DC charging facility, it is possible to quickly determine whether the switch is stuck open or the voltage sensor is broken. ..

1 is an overall configuration diagram of a DC charging system according to an embodiment of the present disclosure. 3 is a flowchart illustrating a procedure of a failure determination process executed by the vehicle ECU shown in FIG. 1. It is the figure which showed the behavior of the detection value of each voltage sensor when a voltage sensor and a DC relay are normal. It is the figure which showed the behavior of the detection value of each voltage sensor when a voltage sensor is abnormal. It is the figure which showed the behavior of the detection value of each voltage sensor when a DC relay is stuck open.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. It should be noted that the same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

FIG. 1 is an overall configuration diagram of a DC charging system according to an embodiment of the present disclosure. Referring to FIG. 1, this DC charging system includes a vehicle 100 and a DC charging facility 500. Vehicle 100 includes a power storage device 110, a system main relay (SMR) 115, a power control unit (PCU) 120, a motor 135, and drive wheels 150.

Power storage device 110 is a rechargeable DC power supply, and is configured to include a secondary battery such as a lithium ion battery or a nickel hydrogen battery. The power storage device 110 can store the electric power supplied from the DC charging facility 500 and the electric power generated by the motor 135 when the vehicle is braked. Then, power storage device 110 can supply the stored electric power to PCU 120.

SMR 115 is provided between power storage device 110 and power lines PL and NL. The SMR 115 is controlled by a signal SR from the vehicle ECU 300, and is in a closed state (conductive state) when the vehicle is running. The SMR 115 is also in the closed state when the power storage device 110 is charged by the DC charging facility 500 (hereinafter referred to as “external charging”).

PCU 120 is electrically connected to power lines PL and NL and controlled by vehicle ECU 300. PCU 120 performs power conversion between power lines PL and NL and motor 135. PCU 120 is configured to include, for example, an inverter that receives DC power from power lines PL and NL to drive motor 135, a converter that adjusts the level of the DC voltage supplied to the inverter, and the like.

The motor 135 is an AC electric motor, for example, a permanent magnet type synchronous electric motor including a rotor in which a permanent magnet is embedded. The motor 135 is driven by an inverter included in the PCU 120 to drive the drive wheels 150. Further, the motor 135 receives the rotational force of the drive wheels 150 to generate electric power when the vehicle is braked. The electric power generated by the motor 135 is stored in the power storage device 110 through the PCU 120.

Vehicle 100 further includes a DC relay 160, a power receiving unit 170, a voltage sensor 180, and a vehicle ECU 300. The power receiving unit 170 is configured to be connectable to the power feeding unit 410 of the charging cable 440 extending from the DC charging facility 500. The configurations of the power receiving unit 170 and the power feeding unit 410 of the charging cable 440 are not particularly limited, but as an example, the power feeding unit 410 is configured by a connector, and the power receiving unit 170 can fit the connector of the charging cable 440. Composed of inlets.

DC relay 160 is provided between power reception unit 170 and power lines PL and NL. The DC relay 160 is controlled by a signal DCR from the vehicle ECU 300, and is controlled to be in a closed state (conductive state) during external charging by the DC charging facility 500.

Voltage sensor 180 detects voltage V1 between the power line pair between DC relay 160 and power reception unit 170, and outputs the detected value to vehicle ECU 300.

The vehicle ECU 300 includes a CPU (Central Processing Unit), a memory (ROM (Read Only Memory) and RAM (Random Access Memory)), an input/output port for inputting/outputting various signals, and the like (all not shown), Various controls in vehicle 100 are executed. As a typical example, when a predetermined traveling condition is satisfied, vehicle ECU 300 controls SMR 115 and DC relay 160 to a closed state and an open state, respectively, and drives PCU 120 to execute vehicle traveling control. Further, vehicle ECU 300 controls both SMR 115 and DC relay 160 to be in a closed state when a predetermined condition for permitting execution of external charging is satisfied. As a result, the DC charging facility 500 is electrically connected to the power storage device 110, and the power storage device 110 can be charged by the DC charging facility 500.

In addition, vehicle ECU 300 is configured to be able to communicate with charging ECU 550 (described later) of DC charging facility 500 through a communication line (not shown) provided in charging cable 440 together with a power line.

DC charging facility 500 includes a power converter 510, a diode 520, voltage sensors 530 and 540, a charging ECU 550, and an operation switch 560.

Power converter 510 is controlled by charging ECU 550, and is configured to convert AC power supplied from a system power supply (for example, AC200V) into DC power for charging power storage device 110 of vehicle 100. Power converter 510 includes, for example, a converter, an inverter, an insulation transformer, a rectifier, and the like.

The diode 520 is provided on the power line between the power converter 510 and the charging cable 440, allows a current to flow from the power converter 510 to the charging cable 440, and causes a current to flow from the charging cable 440 to the power converter 510. Prevent it from flowing.

Voltage sensor 530 detects voltage Vout between the power line pair between power converter 510 and diode 520, and outputs the detected value to charging ECU 550. Voltage sensor 540 detects voltage V2 across the power line pair between diode 520 and power supply unit 410 of charging cable 440, and outputs the detected value to charging ECU 550.

The operation switch 560 is operable by the user and outputs a signal that changes according to the user operation to the charging ECU 550. When the user operates the operation switch 560, various processes for executing external charging are started.

The charging ECU 550 includes a CPU, a memory (ROM and RAM), an input/output port for inputting/outputting various signals, etc. (none of which is shown), and executes various controls in the DC charging facility 500.

As a typical example, when the operation switch 560 is operated by the user while the power feeding unit 410 of the charging cable 440 is connected to the power receiving unit 170 of the vehicle 100, the charging ECU 550 causes the DC charging to be performed prior to the execution of the external charging. The insulation diagnosis of the equipment 500 is performed. Specifically, when DC relay 160 of vehicle 100 is in the open state, charging ECU 550 controls electric power converter 510 to output a voltage from electric power converter 510, and the detected values of voltage sensors 530, 540 and the like. Based on the above, it is diagnosed whether or not insulation deterioration has occurred in the DC charging equipment 500.

In addition, charging ECU 550 is configured to be able to communicate with vehicle ECU 300 of vehicle 100 through a communication line (not shown) arranged in charging cable 440 together with a power line. Then, when the above insulation diagnosis is normally completed and the power supply start signal is received from vehicle ECU 300, charging ECU 550 causes power converter 510 to cause DC charging facility 500 to output charging power for charging power storage device 110. To control.

In the DC charging system as described above, when starting the external charging, the voltage of the electric path between the DC relay and the DC charging equipment is detected when a close command is given to the DC relay with the SMR closed. When the voltage sensor (sensors corresponding to the voltage sensors 180 and 540 in the present embodiment) shows 0 V, it is not possible to determine whether the DC relay is stuck open or the voltage sensor is out of order. ..

Therefore, in the DC charging system according to the present embodiment, when the above-mentioned insulation diagnosis is executed in DC charging facility 500 after power feeding unit 410 of charging cable 440 is connected to power receiving unit 170 of vehicle 100 ( During the insulation diagnosis, the DC charging equipment 500 outputs a voltage with the DC relay 160 open). When the detected value of the voltage sensors 180, 540 indicates 0 V, it means that the voltage sensors 180, 540 have failed. To be judged. Then, when the detection value of the voltage sensors 180, 540 shows a value other than 0V during the execution of the insulation diagnosis (the voltage sensors 180, 540 are normal), the insulation diagnosis ends (the voltage output from the DC charging equipment 500). When the detected values of the voltage sensors 180 and 540 indicate 0 V after the DC relay 160 is closed, it is determined that the DC relay 160 is open and stuck.

Accordingly, when the external charging by the DC charging facility 500 is started, it can be determined whether the DC relay 160 is stuck open or the voltage sensors 180, 540 are out of order. If it is assumed that the diagnosis of the DC relay 160 and the voltage sensors 180 and 540 is performed after the start of external charging, a process of temporarily stopping the output of the DC charging facility 500 or once opening the DC relay 160 is required. According to this DC charging system, at the start of external charging, it is possible to quickly determine whether the DC relay 160 is stuck open or the voltage sensors 180 and 540 are out of order.

FIG. 2 is a flowchart illustrating a procedure of a failure determination process executed by vehicle ECU 300 shown in FIG. When power feeding unit 410 of charging cable 440 is connected to power receiving unit 170 of vehicle 100 and operation switch 560 in DC charging facility 500 is operated by the user, a series of processes shown in this flowchart is started.

Referring to FIG. 2, vehicle ECU 300 starts communication with charging ECU 550 of DC charging facility 500 in response to a communication request from DC charging facility 500 (step S10). In this embodiment, communication between vehicle ECU 300 and charging ECU 550 is performed through a communication line provided in charging cable 440, but wireless communication devices are provided for both vehicle 100 and DC charging facility 500. It may be provided to perform wireless communication.

When the operation switch 560 in the DC charging equipment 500 is operated by the user, the insulation diagnosis described above is executed in the DC charging equipment 500. Then, vehicle ECU 300 receives from DC charging equipment 500 a signal indicating that insulation diagnosis is being executed in DC charging equipment 500 (step S20).

As described above, while the DC charging equipment 500 outputs voltage during execution of the insulation diagnosis in the DC charging equipment 500 (the DC relay 160 is in the open state), the vehicle ECU 300 outputs the detected value of the voltage V1 from the voltage sensor 180. In addition to the acquisition, the detection value of the voltage V2 acquired by the voltage sensor 540 in the DC charging facility 500 is received from the DC charging facility 500 (charging ECU 550) (step S30).

Next, vehicle ECU 300 determines whether or not acquired voltages V1 and V2 are 0V (substantially 0V is sufficient) (step S40). When it is determined that the voltages V1 and V2 are 0V (YES in step S40), the voltage V1, despite the fact that the DC charging equipment 500 is outputting the voltage due to the execution of the insulation diagnosis in the DC charging equipment 500. Since V2 is 0V, vehicle ECU 300 determines that voltage sensors 180 and 540 are defective (step S50). Since the voltage sensors 180, 540 are out of order, vehicle ECU 300 prohibits external charging by DC charging facility 500 (step S60).

On the other hand, when it is determined in step S40 that voltages V1 and V2 are not 0 V (NO in step S40), vehicle ECU 300 determines that voltage sensors 180 and 540 are normal (step S70). Then, vehicle ECU 300 determines whether or not a signal indicating that insulation diagnosis has been completed in DC charging equipment 500 has been received from DC charging equipment 500 (step S80).

When it is determined that the insulation diagnosis is completed in DC charging equipment 500 based on the above signal (YES in step S80), vehicle ECU 300 closes SMR 115 and outputs signal DCR for closing DC relay 160. Output to the DC relay 160 (step S90).

Next, the vehicle ECU 300 acquires the detected value of the voltage V1 from the voltage sensor 180 and receives the detected value of the voltage V2 acquired by the voltage sensor 540 in the DC charging equipment 500 from the DC charging equipment 500 (charging ECU 550) ( Step S100).

Then, vehicle ECU 300 determines whether or not acquired voltages V1, V2 are 0V (substantially 0V is sufficient) (step S110). If it is determined that voltages V1 and V2 are 0V (YES in step S110), the voltages V1 and V2 are 0V even though the voltage of power storage device 110 should be applied through SMR 115. The ECU 300 determines that the DC relay 160 is stuck open (step S120). After that, the process proceeds to step S60, and external charging by the DC charging facility 500 is prohibited.

On the other hand, when it is determined in step S110 that voltages V1 and V2 are not 0 V (NO in step S110), vehicle ECU 300 determines that DC relay 160 is normal (step S130). Then, vehicle ECU 300 transmits a signal instructing the start of external charging to charging ECU 550 of DC charging facility 500, whereby external charging is started (step S140).

3 to 5 are diagrams showing the behavior of the detected value of each voltage sensor for each case when the failure determination process shown in FIG. 2 is executed.

FIG. 3 is a diagram showing the behavior of detection values of the voltage sensors 180 and 540 and the DC relay 160 when the voltage sensors 180 and 540 and the DC relay 160 are normal. In FIG. 3, voltage V1 is a detection value of voltage sensor 180 of vehicle 100, and voltages V2 and Vout are detection values of voltage sensors 540 and 530 of DC charging facility 500, respectively (see FIGS. 4 and 5 described later). The same).

Referring to FIG. 3, operation switch 560 of DC charging equipment 500 is operated by the user, and at time t1, insulation diagnosis is started in DC charging equipment 500. As described above, during the insulation diagnosis, the voltage is output from the DC charging facility 500 and the voltage Vout becomes a non-zero predetermined value. In this example, since the voltage sensors 180 and 540 are normal, the voltages V1 and V2 also have non-zero predetermined values (NO in step S40 of FIG. 2).

At time t2, the power converter 510 of the DC charging equipment 500 is stopped, and the voltages Vout, V1, and V2 are 0V accordingly. Then, the insulation diagnosis ends at time t3, and at time t4, an opening command is output to DC relay 160 (and SMR 115) in vehicle 100. In this example, since the DC relay 160 is normal, the DC relay 160 is in the open state, and the voltages V1 and V2 are nonzero predetermined values (NO in step S110 of FIG. 2).

Then, when the non-zero voltage V2 is detected in the DC charging equipment 500, the DC relay 160 (and the voltage sensors 180, 540) is judged to be normal (step S130 in FIG. 2), and the DC charging equipment 500 converts the power. When the device 510 is driven, the charging voltage appears in the voltage Vout. This starts external charging.

FIG. 4 is a diagram showing the behavior of the detected value of each voltage sensor when the voltage sensors 180 and 540 are out of order. Referring to FIG. 4, when insulation diagnosis is started in DC charging equipment 500 at time t1, voltage Vout becomes a non-zero predetermined value. However, in this example, since the voltage sensors 180 and 540 are out of order, the voltages V1 and V2 remain 0V (YES in step S40 of FIG. 2). Therefore, external charging is prohibited (step S60 in FIG. 2), and the DC relay 160 is not closed thereafter.

FIG. 5 is a diagram showing the behavior of the detected value of each voltage sensor when the DC relay 160 is stuck open. Referring to FIG. 5, when insulation diagnosis is started in DC charging equipment 500 at time t1, voltage Vout becomes a non-zero predetermined value. In this example, since the voltage sensors 180 and 540 are normal, the voltages V1 and V2 also have non-zero predetermined values (NO in step S40 of FIG. 2).

At time t2, the DC charging facility 500 is stopped, and the voltages Vout, V1 and V2 are 0V accordingly. Then, the insulation diagnosis ends at time t3, and at time t4, an opening command is output to DC relay 160 (and SMR 115) in vehicle 100. In this example, since the DC relay 160 is stuck open, the voltages V1 and V2 remain 0V (YES in step S110 of FIG. 2). Therefore, external charging is prohibited, the power converter 510 is not subsequently driven in the DC charging facility 500, and the charging voltage does not appear in the voltage Vout.

As described above, according to this embodiment, at the start of external charging by the DC charging facility 500, it is determined whether the DC relay 160 is stuck open or the voltage sensors 180, 540 are out of order. be able to. If it is assumed that the diagnosis of the DC relay 160 and the voltage sensors 180 and 540 is performed after the start of external charging, a process of temporarily stopping the output of the DC charging facility 500 or once opening the DC relay 160 is required. According to this embodiment, at the start of external charging, it is possible to quickly determine whether DC relay 160 is open and stuck, or whether voltage sensors 180 and 540 are out of order.

In the above embodiment, the failure determination is performed on the voltage sensors 180 and 540 as a set. However, it is not always necessary to determine the failure on the voltage sensors 180 and 540 as a set. The failure determination processing and the failure diagnosis of the voltage sensor may be performed by using the failure determination processing.

Further, in the above-described embodiment, the series of processes shown in FIG. 2 is executed in vehicle ECU 300 mounted on vehicle 100, but is executed in charging ECU 550 provided in DC charging facility 500. It may be one. In that case, the detected value of voltage V1 by voltage sensor 180 of vehicle 100 and the like are transmitted from vehicle ECU 300 to charging ECU 550.

In the above description, DC relay 160 corresponds to an example of “switch” in the present disclosure, and at least one of voltage sensors 180 and 540 corresponds to an example of “voltage sensor” in the present disclosure.

It should be considered that the embodiments disclosed this time are exemplifications in all points and not restrictive. The scope of the present disclosure is shown not by the above description of the embodiments but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

100 vehicle, 110 power storage device, 115 SMR, 120 PCU, 135 motor, 150 driving wheel, 160 DC relay, 170 power receiving unit, 180, 530, 540 voltage sensor, 300 vehicle ECU, 410 power feeding unit, 440 charging cable, 500 DC Charging equipment, 510 power converter, 520 diode, 550 charging ECU, 560 operation switch.

Claims (4)

A power storage device that is charged by a DC charging facility that supplies DC power,
A power receiving unit configured to receive the DC power from the DC charging facility and output the power to the power storage device,
A switch provided in an electric path between the power receiving unit and the power storage device,
A voltage sensor that detects the voltage of the electric path between the switch and the DC charging facility,
A controller configured to determine a failure of the switch and the voltage sensor,
The DC charging equipment, when the DC charging equipment is connected to the power receiving unit, is configured to output a voltage before the switch is closed to perform insulation diagnosis of the DC charging equipment,
The control device is configured to execute first and second determination processes,
Wherein the first determination process, when the detected value of the voltage sensor during execution of the insulation diagnosis indicates zero, a process for determining as said voltage sensor is faulty,
In the second determination processing, when the detection value of the voltage sensor indicates non-zero during execution of the insulation diagnosis, the detection value is zero after the insulation diagnosis is completed and the switch is closed. When indicated, the charging system is a process of determining that the switch is stuck open. The charging according to claim 1, wherein when the control device determines that the voltage sensor has failed in the first determination process, charging of the power storage device by the DC charging facility is not permitted. system. The control device disallows charging of the power storage device by the DC charging facility when it is determined that the switch is open and stuck in the second determination process. The charging system according to 2. The DC charging facility includes an operation switch operable by a user,
The charging system according to claim 1, wherein the control device performs the first and second determination processes after the operation switch is operated.

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