JP2020091141A - Both-electrode welding diagnosis device of charging relay - Google Patents

Abstract

To perform welding diagnosis of a charging relay even when a charging voltage sensor has a failure.SOLUTION: A vehicle comprises: a battery; an electric leak detection circuit connected to both electrodes of the battery; a connector connected to an external DC power source; and a charging relay attached to a charging line connecting an electric power line between a system main relay and an electrical load, and the connector. Furthermore, the vehicle has an insulation reduction circuit attached to the charging line between the charging relay and the connector. Under the condition where the charging relay is turned off and the system main relay is turned on, it is diagnosed that the charging relay has had welding of both electrodes if electric leak is detected by the electric leak detection circuit when the insulation reduction circuit maintains insulation to one side of the charging line while reducing insulation to the other side, and electric leak is detected by the electric leak detection circuit when the insulation reduction circuit maintains insulation to the other side while reducing insulation to the one side.SELECTED DRAWING: Figure 1

Description

The present invention relates to a bipolar welding diagnostic device for a charging relay.

Conventionally, as a technique of this kind, a welding diagnosis device has been proposed that performs welding diagnosis of a relay provided in an electric power line that supplies electric power from a battery to a high-voltage unit (see, for example, Patent Document 1). This welding diagnostic device is equipped with a pseudo leakage circuit connected to the power line between the relay and the high-voltage unit, and the pseudo leakage circuit causes a pseudo leakage to determine whether or not there is a leakage of the relay. Make a diagnosis.

JP, 2013-68479, A

In a vehicle equipped with a battery that is connected to an electric load via a system main relay, in order to charge the battery with the electric power from the external DC power supply, an inlet (connection part) connected to the external DC power supply and the electric load Some include a charging relay attached to a charging line connecting an electric power line with the system main relay and an inlet. In this vehicle, the welding diagnosis of the charging relay is performed at the end of charging, but the welding diagnosis of the charging relay may not be performed for some reason such as the disconnection of the external DC power supply and the inlet. In this case, the welding diagnosis of the charging relay is performed when the system of the vehicle is started.However, when a failure occurs in the charging voltage sensor installed between the charging relay and the inlet, the welding diagnosis of the charging relay is performed. I can't do it.

The bipolar welding diagnostic device for a charging relay according to the present invention is mainly intended to perform welding diagnostics on a charging relay even when a failure has occurred in the charging voltage sensor.

The bipolar welding diagnostic device for the charging relay of the present invention employs the following means in order to achieve the above-mentioned main object.

The bipolar welding diagnostic device of the charging relay of the present invention,
A battery,
A system main relay attached to the power line between the battery and the electrical load;
A leakage detection circuit connected to both electrodes of the battery,
A connection part connected to an external DC power supply,
A charging relay attached to a charging line connecting the electric power line between the system main relay and the electric load and the connecting portion,
A bipolar welding diagnostic device for a charging relay, which is mounted on a vehicle equipped with and which diagnoses bipolar welding of the charging relay,
An insulation degradation circuit attached to the charging line between the charging relay and the connection portion,
With the charging relay turned off and the system main relay turned on, the insulation lowering circuit maintained insulation on one side of the charging line and lowered insulation on the other side. When leakage is detected by the leakage detection circuit, and when leakage is detected by the leakage detection circuit when insulation is reduced for the other while insulation is maintained for the other The charging relay is a diagnostic unit for diagnosing bipolar welding,
The main point is to provide.

A vehicle equipped with the bipolar welding diagnostic device for a charging relay according to the present invention includes a battery, a system main relay attached to a power line between the battery and an electric load, and an earth leakage detection circuit connected to both electrodes of the battery. And a connecting portion connected to the external DC power supply, and a charging relay attached to a charging line connecting the electric power line between the system main relay and the electric load and the connecting portion. The bipolar welding diagnostic device for a charging relay according to the present invention includes an insulation lowering circuit attached to a charging line between the charging relay and the connecting portion, and turns off the charging relay and turns on the system main relay. In this state, when the insulation lowering circuit maintains insulation for one of the charging lines and lowers the insulation for the other, leakage is detected by the leakage detection circuit, and When the leakage is detected by the leakage detection circuit when the insulation is lowered for one side while the insulation is maintained, the charging relay is diagnosed as having both electrodes welded. Thereby, even if the charging voltage sensor mounted between the charging relay and the inlet is out of order, welding diagnosis of the charging relay can be performed.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 which mounts the bipolar welding diagnosis device of the charging relay as one Example of this invention. It is a block diagram which shows the outline of a structure of charge integrated ECU50. 6 is a flowchart showing an example of system-on processing executed by a main ECU 60. It is explanatory drawing which shows a mode of the electric current which flows into insulation reduction circuit 54, when switches S1 and S4 are turned on, when welding has arisen in the positive electrode side relay of charging relay 42. It is explanatory drawing which shows a mode of the electric current which flows into insulation reduction circuit 54, when switches S2 and S3 are turned on when welding has arisen in the negative electrode side relay of charging relay 42. It is explanatory drawing which shows the operation|movement at the time of a system-on process when welding is not generate|occur|produced at both electrodes of the charging relay 42. It is explanatory drawing which shows the operation|movement at the time of a system-on process when welding has arisen only in the positive electrode side relay of the charging relay 42. It is explanatory drawing which shows operation|movement at the time of a system-on process when welding has generate|occur|produced in both the positive electrode side relay and the negative electrode side relay of the charging relay 42.

Next, modes for carrying out the present invention will be described using examples.

FIG. 1 is a schematic diagram showing the configuration of an electric vehicle 20 equipped with a bipolar welding diagnostic device for a charging relay as an embodiment of the present invention. The electric vehicle 20 of the embodiment includes a battery 22, a battery electronic control unit (hereinafter referred to as “battery ECU”) 24, a system main relay 32, and a power control unit (hereinafter referred to as “PCU”) 34. , A motor 36, a charging relay 42, a DC power supply inlet (hereinafter referred to as “DC inlet”) 44, a charge integrated electronic control unit (hereinafter referred to as “charge integrated ECU”) 50, and main electronic control. A unit (hereinafter referred to as “main ECU”) is provided.

The battery 22 is composed of, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery. The system main relay 32 is attached to the power line 30 that connects the battery 22 and the PCU 34. The PCU 34 is configured by, for example, an inverter circuit that converts DC power into AC power to drive the motor 36, a step-up/down converter that adjusts the voltage of DC power supplied to the inverter circuit, and the like. The motor 36 is composed of, for example, a synchronous generator motor or an induction motor.

Although not shown, the battery ECU 24 is configured as a microcomputer centering on a CPU, and includes a ROM, a RAM, a flash memory, an input/output port, a communication port, and the like in addition to the CPU. The battery ECU 24 is connected to both electrodes of the battery 22, and detects the current flowing in the battery 22, the voltage of both electrodes of the battery 22, the temperature of the battery 22, and the like. A leakage detection circuit 26 is incorporated in the battery ECU 24. The electric leakage detection circuit 26 is configured as a known electric leakage detection circuit, and detects electric leakage of the system.

The charging relay 42 is attached to the charging line 40 that connects the power line 30 between the system main relay 32 and the PCU 34 and the DC inlet 44.

FIG. 2 is a configuration diagram showing an outline of the configuration of the charge integration ECU 50. The charge integration ECU 50 includes a microcomputer 51 having a CPU, a ROM, a RAM, a flash memory, an input/output port, a communication port and the like (not shown), a charging voltage sensor (hereinafter, referred to as “DCV sensor”) 52, and an insulation lowering circuit. 54 and. The charge integration ECU 50 is connected to the DC inlet 44 by a signal line, and detects whether a lid (lid) (not shown) of the DC inlet 44 is open or closed by a signal from the signal line. The DCV sensor 52 is a sensor that detects the voltage of the charging line 40, and includes the circuit shown in FIG. Since the configuration of the DCV sensor 52 does not form the core of the invention, further detailed description of the DCV sensor 52 will be omitted. A signal from the DCV sensor 52, a signal from the insulation lowering circuit 54, etc. are input to the microcomputer 51 via an input port. Further, a drive signal to the charging relay 42, a drive signal to the switches S1 to S5 of the insulation lowering circuit 54 described later, and the like are output from the microcomputer 51 via the output port.

As shown in the figure, the insulation lowering circuit 54 includes a switch S1 and a switch S3 connected in series to the positive side line of the charging line 40, and a switch S2 and a switch connected in series to the negative side line of the charging line 40. S4, a capacitor C1 connected to a connection point between the switch S1 and the switch S3 and a connection point between the switch S2 and the switch S4, and a connection between the switch S1 and the switch S3 so as to be connected in parallel to the capacitor C1. A resistor R1 and a switch S5 connected in series to a point and a connection point of the switch S2 and the switch S4; and a comparator 56 which inputs the other point of the switch S3 and the other point of the switch S4 and outputs the same to the microcomputer 51. , A resistor R3 interposed between the other point of the switch S3 and the ground, and a resistor R3 interposed between the other point of the switch S4 and the ground. When the switches S1 and S4 are turned on and the switches S2, S3 and S5 are turned off, the insulation lowering circuit 54 grounds the positive line of the charging line 40 via the switch S1, the capacitor C1, the switch S4 and the resistor R3. Therefore, the insulation of the positive line of the charging line 40 can be reduced. When the switches S2, S3 are turned on and the switches S1, S4, S5 are turned off, the negative side line of the charging line 40 is grounded via the switch S2, the capacitor C1, the switch S3, and the resistor R2. The insulation of the negative line of the line 40 can be reduced.

Although not shown, the main ECU 60 is configured as a microcomputer centered on a CPU, and includes a ROM, a RAM, a flash memory, an input/output port, a communication port, and the like in addition to the CPU. The main ECU 60 functions as a drive control device for the electric vehicle 20. Therefore, in the main ECU 60, the voltage V from the voltage sensor (not shown) attached to the power line 30, the PCU temperature from the temperature sensor (not shown) attached to the PCU 34, the phase current of the motor 36 from the phase current sensor (not shown). Is input through the input port. In addition, the IG signal from an ignition switch (IG switch) (not shown), the shift position from the shift position, the accelerator opening from the accelerator pedal position sensor, the brake position from the brake position sensor, etc. are also input via the input port. ing. From the main ECU 60, a drive control signal to the PCU 34 (for example, a switching control signal of a switching element of an inverter circuit or a switching control signal of a switching element of a step-up/down converter) or a drive signal to the system main relay 32 is output port. Is output via. The main ECU 60 communicates necessary information with the battery ECU 24 and the charge integration ECU 50 via the communication port.

Next, the operation of the electric vehicle 20 equipped with the bipolar welding diagnosis device for the charging relay of the embodiment thus configured, in particular, the DCV sensor 52 has a failure, and the battery 22 is charged by the electric power from the external DC power supply. The operation when the system is turned on (ignition on: IG on) without the welding diagnosis of charging relay 42 being performed at the end will be described. FIG. 3 is a flowchart showing an example of the system-on process executed by the main ECU 60 when the welding relay 42 for charging is not diagnosed at the end of charging the battery 22 and the system is turned on.

When the system-on process is executed, the main ECU 60 first determines whether or not the DC lid is closed (step S100). For opening and closing the DC lid, a signal from a signal line connected to the DC inlet 44 is input from the charge integration ECU 50 by communication. When it is determined that the DC lid is open, other processing is not performed and the process waits until the DC lid is closed. At this time, it may be notified that the DC lid is open.

When it is determined in step S100 that the DC lid is closed, the system main relay 32 is turned on (step S110). Then, the charging relay 42 is turned off, the switches S1 and S4 of the insulation lowering circuit 54 are turned on (step S120), and it is determined whether or not the leakage detection circuit 26 of the battery ECU 24 detects the leakage (step S130). The ON/OFF operation of the switches S1 and S4 of the insulation lowering circuit 54 is performed by the charge integrated ECU 50 that transmits a control signal for turning on/off the switches S1 and S4 to the charge integrated ECU 50 and receives the control signal. The off state of the charging relay 42 can be confirmed by the charge integration ECU 50. FIG. 4 is an explanatory diagram showing a state of a current flowing through the insulation lowering circuit 54 when the switches S1 and S4 are turned on when the positive electrode-side relay of the charging relay 42 is welded. When welding is occurring on the positive electrode side relay of the charging relay 42, as shown in FIG. 4, the switch S1, the capacitor C1, the switch S4, the resistor R3, from the positive electrode side line of the charging line to which the positive electrode side relay is attached, A current flows until the capacitor C1 is charged in the order of grounding. Therefore, the leakage detection circuit 26 of the battery ECU 24 detects the leakage. On the other hand, when welding does not occur in the positive electrode-side relay of the charging relay 42, the current as shown in FIG. 4 does not flow, so the leakage detection circuit 26 of the battery ECU 24 does not detect the leakage.

When it is determined in step S130 that the leakage detection circuit 26 of the battery ECU 24 has not detected the leakage, it is determined that the bipolar welding of the charging relay 42 has not occurred (step S170), and ready-on (step S180) is performed. Is set to a travelable state, and this processing ends.

When it is determined in step S130 that the leakage detection circuit 26 of the battery ECU 24 has detected the leakage, the switches S1 and S4 of the insulation lowering circuit 54 are turned off (step S140), the charging relay 42 is turned off, and the insulation lowering circuit 54 is turned off. The switches S2 and S3 are turned on (step S150), and it is determined whether or not the leakage detection circuit 26 of the battery ECU 24 has detected the leakage (step S160). FIG. 5 is an explanatory diagram showing a state of a current flowing through the insulation lowering circuit 54 when the switches S2 and S3 are turned on when the negative electrode side relay of the charging relay 42 is welded. When welding is occurring on the negative electrode side relay of the charging relay 42, as shown in FIG. 5, the negative electrode side of the charging line to which the resistor R2, the switch S3, the capacitor C1, the switch S2, and the negative electrode side relay are attached from the ground. The current flows until the capacitor C1 is charged in the order of the lines. Therefore, the leakage detection circuit 26 of the battery ECU 24 detects the leakage. On the other hand, when welding is not occurring in the negative-side relay of the charging relay 42, the current as shown in FIG. 5 does not flow, so the leakage detection circuit 26 of the battery ECU 24 does not detect leakage.

When it is determined in step S160 that the leakage detection circuit 26 of the battery ECU 24 has not detected leakage, the charging relay 42 has the positive electrode side relay welded but the negative electrode side relay not welded. It is determined that both electrodes are not welded (step S170), the system is ready to be turned on (step S180), the system is ready to run, and the process ends.

When it is determined in step S160 that the leakage detection circuit 26 of the battery ECU 24 has detected the leakage, the charging relay 42 is welded (both electrodes are welded) to both the positive side relay and the negative side relay of the charging relay 42. It is determined that both electrodes are welded (step S190), the system main relay 32 is turned off (step S200), traveling is prohibited, and this processing is ended.

FIG. 6 is an explanatory diagram showing an operation at the time of system-on processing when welding does not occur on both electrodes of the charging relay 42. In this case, when the IG switch is turned on at time T1, the system main relay 32 is turned on at time T2. At the next time T3, the switches S1 and S4 of the insulation lowering circuit 54 are turned on, and at time T4, the leakage detection circuit 26 of the battery ECU 24 determines whether or not there is a leakage. In this case, since neither electrode of the charging relay 42 is welded, no leakage is detected. As a result, it is determined that both electrodes of the charging relay 42 have not been welded, and the charging relay 42 is turned on.

FIG. 7 is an explanatory diagram showing the operation during system-on processing when welding has occurred only on the positive electrode side relay of the charging relay 42. In this case, when the IG switch is turned on at time T1, the system main relay 32 is turned on at time T2, and the switches S1 and S4 of the insulation lowering circuit 54 are turned on at time T3. At time T4, the leak detection circuit 26 of the battery ECU 24 detects the leak. At the next time T5, the switches S1 and S4 are turned off, at times T6, the switches S2 and S3 are turned on, and at time T7, the presence or absence of leakage is detected by the leakage detection circuit 26 of the battery ECU 24. Since no welding occurs on the negative-side relay of the charging relay 42, no electric leakage is detected. As a result, it is determined that both electrodes of the charging relay 42 are not welded, and the charging relay 42 is turned on.

FIG. 8 is an explanatory diagram showing an operation at the time of system-on processing when welding is occurring in both the positive electrode side relay and the negative electrode side relay of the charging relay 42. In this case, when the IG switch is turned on at time T1, the system main relay 32 is turned on at time T2, and the switches S1 and S4 of the insulation lowering circuit 54 are turned on at time T3. At time T4, the leak detection circuit 26 of the battery ECU 24 detects the leak. The switches S1 and S4 are turned off at the next time T5, the switches S2 and S3 are turned on at the time T6, and the leakage detection circuit 26 of the battery ECU 24 detects the leakage at time T7. Therefore, it is determined that both the positive side relay and the negative side relay of the charging relay 42 have been welded (both electrode welding), and the system main relay 32 is turned off at time T8.

The electric vehicle 20 equipped with the bipolar welding diagnosis device for the charging relay according to the embodiment described above is provided with the insulation lowering circuit 54 for individually performing insulation lowering of the positive side and negative side of the charging line 40. , When the IG switch is turned on, the system main relay 32 is turned on and the charging relay 42 is turned off, so that the insulation of the positive electrode side and the insulation of the negative electrode side of the charging line 40 are reduced. At that time, when leakage is detected by the leakage detection circuit 26 of the battery ECU 24, it is determined that both electrodes of the charging relay 42 are welded, and traveling is prohibited. As a result, even when the DCV sensor 52 has a failure, it is possible to diagnose the bipolar welding of the charging relay 42.

In the electric vehicle 20 equipped with the bipolar welding diagnosis device for the charging relay according to the embodiment, the leakage detection circuit 26 is assumed to be incorporated in the battery ECU 24, but the leakage detection circuit 26 is not incorporated in the battery ECU 24, and another circuit is provided. You may comprise as.

In the electric vehicle 20 equipped with the bipolar welding diagnostic device for the charging relay of the embodiment, the insulation lowering circuit 54 is assumed to be incorporated in the charge integrated ECU 50, but the insulation lowering circuit 54 is not incorporated in the charge integrated ECU 50 and is different. May be configured as a circuit.

Although the electric vehicle 20 equipped with the bipolar welding diagnosis device for the charging relay according to the embodiment has three electronic control units including the battery ECU 24, the charge integration ECU 50, and the main ECU 60, the battery ECU 24, the charge integration ECU 50, and the main ECU 60 are provided. One of the ECU 60 and the electronic control unit may also serve as the other electronic control unit, or may be configured by a single electronic control unit.

Correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the example,
The battery 22 corresponds to a “battery”, the system main relay 32 corresponds to a “system main relay”, the leakage detection circuit 26 corresponds to a “leakage detection circuit”, the DC inlet 44 corresponds to a “connecting portion”, The charging relay 42 corresponds to the “charging relay”, the insulation lowering circuit 54 corresponds to the “insulation lowering circuit”, and the main ECU 60, the battery ECU 24, and the charge integrated ECU 50 correspond to the “diagnosis unit”.

The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the section of means for solving the problem. This is an example for specifically explaining the mode for carrying out the invention, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problem should be made based on the description in that column, and the embodiment is the invention of the invention described in the column of means for solving the problem. This is just a specific example.

Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope not departing from the gist of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention can be used in the manufacturing industry of a bipolar welding diagnostic device for a charging relay mounted on a vehicle.

20 electric vehicle, 22 battery, 24 battery electronic control unit (battery ECU), 30 power line, 32 system main relay, 34 power control unit (PCU), 36 motor, 40 charging line, 42 charging relay, 44 direct current Power supply inlet (DC inlet), 50 charge integrated electronic control unit (charge integrated ECU), 52 charge voltage sensor (DCV sensor), 54 insulation reduction circuit, 56 comparator, 60 main electronic control unit (main ECU), C1 capacitor , R1, R2, R3 resistors, S1, S2, S3, S4, S5 switches.

Claims (1)

A battery,
A system main relay attached to the power line between the battery and the electrical load;
A leakage detection circuit connected to both electrodes of the battery,
A connection part connected to an external DC power supply,
A charging relay attached to a charging line connecting the electric power line between the system main relay and the electric load and the connecting portion,
A bipolar welding diagnostic device for a charging relay, which is mounted on a vehicle equipped with and which diagnoses bipolar welding of the charging relay,
An insulation degradation circuit attached to the charging line between the charging relay and the connection portion,
With the charging relay turned off and the system main relay turned on, the insulation lowering circuit maintained insulation on one side of the charging line and lowered insulation on the other side. When leakage is detected by the leakage detection circuit, and when leakage is detected by the leakage detection circuit when insulation is reduced for the other while insulation is maintained for the other The charging relay is a diagnostic unit for diagnosing bipolar welding,
Charging relay bipolar welding diagnostic device.

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