JP2022128677A - Power supply device - Google Patents

Abstract

To prevent lifetime of a relay from being shortened.SOLUTION: A power supply device comprises: a power storage device; a converter capable of executing a step-down operation by stepping down power of a first power line to which the power storage device is connected to supply power to a second power line; a relay comprising a positive electrode side relay provided on the power storage device side of the converter of a positive electrode line of the first power line, and a negative electrode side relay provided on the power storage device side of the converter of a negative electrode line of the first power line; and a control device for controlling the relay while controlling the converter together with communication. The converter executes the step-down operation when communication with the control device is disconnected. When opening the positive electrode side relay and the negative electrode side relay one by one upon disconnection of the communication with the converter, the control device opens in a reverse order to an order as of the previous time of opening the positive electrode side relay and the negative electrode side relay one by one upon disconnection of the communication with the converter.SELECTED DRAWING: Figure 2

Description

The present invention relates to a power supply device.

Conventionally, this type of power supply includes a high-voltage battery, a low-voltage battery, electrical equipment connected to the low-voltage battery through a power supply path, and a high DC voltage from the high-voltage battery to a low DC voltage. A DC-DC converter that converts and supplies power to the power supply path, a power supply switching switch provided on the low voltage battery side of the connection point with the DC-DC converter in the power supply path, and a control unit having a CAN communication unit. , has been proposed (see, for example, Patent Document 1). In this power supply device, the power switch is normally turned on, and when the voltage of the low-voltage battery is equal to or higher than a predetermined value, the power from the high-voltage battery and the low-voltage battery is used to drive the electrical components, and the low-voltage battery is less than a predetermined value, the power from the high voltage battery is used to drive electrical equipment and charge the low voltage battery. On the other hand, when the control unit detects an abnormality in communication with the higher-level ECU, the power switch is turned off, and the electrical equipment is driven using the power from the high-voltage battery.

JP 2016-213965 A

In addition to the hardware configuration of the power supply described above, the power supply further includes a relay between the high voltage battery and the DC-DC converter. When opening the relay while driving the DC-DC converter, the positive side of the relay and the An arc may occur on the side of the negative relay that opens first. If arcing occurs in one of the positive side relay and the negative side relay of the relay, the life of the relay may be shortened.

A main object of the power supply device of the present invention is to suppress shortening of the life of the relay.

The power supply device of the present invention employs the following means in order to achieve the above main object.

The power supply device of the present invention is
a power storage device;
a converter capable of step-down operation for stepping down the power of the first power line to which the power storage device is connected and supplying the power to the second power line;
a positive side relay provided closer to the power storage device than the converter on the positive side line of the first power line; and a positive side relay provided closer to the power storage device than the converter on the negative side line of the first power line. a relay having a negative relay;
a control device that controls the converter and the relay with communication;
A power supply device comprising:
The converter performs a step-down operation when communication with the control device is interrupted,
When communication with the converter is interrupted and the positive electrode side relay and the negative electrode side relay are opened one by one, the control device opens the positive electrode side relay and the positive electrode side relay when communication with the converter was previously interrupted. Open the negative side relays one by one in the reverse order,
This is the gist of it.

In the power supply device of the present invention, the converter performs a step-down operation when communication with the control device is interrupted, and the control device operates one positive relay and one negative relay when communication with the converter is interrupted. When opening the relays, they are opened in the reverse order of the previous time when the communication with the converter was interrupted and the positive side relay and the negative side relay were opened one by one. As a result, it is possible to suppress biased influence (stress) due to the occurrence of an arc on one of the positive side relay and the negative side relay of the relay. As a result, shortening of the life of the relay can be suppressed.

1 is a configuration diagram showing a schematic configuration of an electric vehicle 20 equipped with a power supply device according to an embodiment of the present invention; FIG. 4 is a flowchart showing an example of a processing routine executed by an ECU 70;

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

FIG. 1 is a configuration diagram showing the outline of the configuration of an electric vehicle 20 equipped with a power supply device as one embodiment of the present invention. An electric vehicle 20 equipped with the power supply device of the embodiment, as illustrated, includes a motor 32, an inverter 34, a battery 36 as a power storage device, a high voltage side power line 38, a system main relay SMR, an auxiliary device It includes a battery 40 , a low-voltage side power line 42 , a DC/DC converter 48 , and an electronic control unit (hereinafter referred to as “ECU”) 70 . The power supply device of the embodiment mainly includes the battery 36, the system main relay SMR, the DC/DC converter 48, and the ECU 70. FIG.

The motor 32 is configured as a synchronous generator-motor, and includes a rotor in which permanent magnets are embedded in a rotor core, and a stator in which a three-phase coil is wound around the stator core. The rotor of the motor 32 is connected to a drive shaft 26 which is connected to drive wheels 22a and 22b through a differential gear 24. As shown in FIG. An inverter 34 is connected to the motor 32 and to the high voltage side power line 38. The inverter 34 is configured as a well-known inverter circuit having six transistors and six diodes. The motor 32 is rotationally driven by switching control of a plurality of switching elements (not shown) of the inverter 34 . The inverter 34 is connected to the ECU 70 via a communication line (for example, a communication line for CAN communication).

The battery 36 is configured as, for example, a lithium-ion secondary battery or a nickel-hydrogen secondary battery with a rated voltage of about several hundred volts, and is connected to the high-voltage side power line 38 . A capacitor 39 is connected to the positive electrode bus and the negative electrode bus of the high-voltage power line 38 .

The system main relay SMR is provided on the high voltage side power line 38 . This system main relay SMR has a positive relay SMRB provided on the positive bus of the high-voltage power line 38 and a negative relay SMRG provided on the negative bus of the high-voltage power line 38 . System main relay SMR connects and disconnects (opens) the inverter 34 side and the battery 36 side by turning it on and off. System main relay SMR is connected to ECU 70 via a communication line (for example, a communication line for CAN communication).

The auxiliary battery 40 is configured as, for example, a lithium-ion secondary battery, a nickel-hydrogen secondary battery, or a lead-acid battery with a rated voltage of about ten and several volts. It is connected to the side power line 42 .

The DC/DC converter 48 is connected to the inverter 34 side and the low-voltage power line 42 rather than the system main relay SMR of the high-voltage power line 38 . This DC/DC converter 48 steps down the power on the high voltage side power line 38 and supplies it to the low voltage side power line 42 , or boosts the power on the low voltage side power line 42 to supply it to the high voltage side power line 38 . supply. The DC/DC converter 48 is connected to the ECU 70 and the like via a communication line (for example, a communication line for CAN communication).

Although not shown, the ECU 70 is configured as a microprocessor centered on a CPU. Equipped with input/output ports and communication ports. The ECU 70 is connected to the inverter 34, the system main relay SMR, and the DC/DC converter 48 via communication lines (for example, communication lines for CAN communication).

Signals from various sensors are input to the ECU 70 through input ports. Signals input to the ECU 70 include, for example, a rotational position θm from a rotational position detection sensor (for example, a resolver) 32a that detects the rotational position of the rotor of the motor 32, and a voltage sensor 36a attached between the terminals of the battery 36. and a current Ib from a current sensor 36b attached to the output terminal of the battery 36. Also, the voltage VH of the capacitor 39 (high-voltage side power line 38) from the voltage sensor 39a attached between the terminals of the capacitor 39 can be cited. The ignition signal from the ignition switch 80, the shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, and the brake A brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of the pedal 85 and a vehicle speed V from a vehicle speed sensor 87 can also be used. The operation positions of the shift lever 81 (shift position SP detected by the shift position sensor 82) include a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position). )and so on.

Various control signals are output from the ECU 70 through an output port. Signals output from the ECU 70 include, for example, a control signal to the transistor of the inverter 34, a control signal to the system main relay SMR, and a control signal to the DC/DC converter 48.

Next, the operation of the electric vehicle 20 of the embodiment configured as described above, in particular, the operation when opening the system main relay SMR will be described. FIG. 2 is a flow chart showing an example of a processing routine executed by the ECU 70. As shown in FIG. This routine is executed when opening of the system main relay SMR is requested while the DC/DC converter 48 is being driven. Here, when the system main relay SMR is requested to be opened, for example, when the ignition signal from the ignition switch 80 changes from ON to OFF, or when an abnormality of the battery 36 is detected.

When the processing routine of FIG. 2 is executed, ECU 70 first determines whether communication with DC/DC converter 48 is interrupted (step S100). This processing can be performed, for example, by determining whether or not a predetermined time has passed since communication with the DC/DC converter 48 was performed last time. When it is determined that communication with the DC/DC converter 48 has not been interrupted, a normal end sequence is executed (step S110), and this routine ends. In a normal end sequence, after stopping the driving of DC/DC converter 48, positive side relay SMRB and negative side relay SMRG of system main relay SMR are opened.

When it is determined in step S100 that communication with the DC/DC converter 48 has been interrupted, the negative relay SMRG and the positive It is determined whether or not the side relays SMRB are opened in order (step S130). Note that the DC/DC converter 48 executes or continues the step-down operation when communication with the ECU 70 is interrupted. This is to prevent the voltage of the high-voltage power line 38 from rising due to the regenerative driving of the motor 32 or the like.

If it is determined in step S130 that the negative relay SMRG and the positive relay SMRB were opened in this order when the communication with the DC/DC converter 48 was interrupted last time and the system main relay SMR was opened, then the positive relay SMRB and the negative relay SMRB were opened. The system main relays SMR are controlled to open in order of the side relays SMRG (step S140), and this routine ends.

In step S130, when the communication with the DC/DC converter 48 was interrupted last time and the system main relay SMR was opened, the negative electrode side relay SMRG and the positive electrode side relay SMRB were not opened in this order (positive electrode side relay SMRB, negative electrode side relay SMRG is opened in this order), the system main relay SMR is controlled so that the negative relay SMRG and the positive relay SMRB are opened in this order (step S150), and this routine ends.

When the system main relay SMR is opened while driving the DC/DC converter 48, an arc may occur in the side of the positive side relay SMRB or the negative side relay SMRG that is opened first. Based on this, in the embodiment, the positive side relays are opened in the reverse order of the previous time when the positive side relay SMRB and the negative side relay SMRG of the system main relay SMR were opened one by one while driving the DC/DC converter 48. By opening the SMRB and the negative side relay SMRG, it is possible to suppress biased influence (stress) due to arc generation on either the positive side relay SMRB or the negative side relay SMRG of the system main relay SMR. can be done. As a result, shortening of the life of system main relay SMR can be suppressed.

In the power supply device of the embodiment described above, the DC/DC converter 48 executes a step-down operation when communication with the ECU 70 is interrupted, and the ECU 70 operates when communication with the DC/DC converter 48 is interrupted and the positive electrode side relay When opening the SMRB and the negative relay SMRG one by one, the operation is reversed from when the communication with the DC/DC converter 48 was interrupted last time and the positive relay SMRB and the negative relay SMRG were opened one by one. Open in order. As a result, it is possible to suppress biased influence (stress) due to the generation of an arc on one of the positive side relay SMRB and the negative side relay SMRG of the system main relay SMR. As a result, shortening of the life of system main relay SMR can be suppressed.

In the embodiment, a form of a power supply device mounted on an electric vehicle 20 having a motor 32, a battery 36, a system main relay SMR, and a DC/DC converter 48 is used. However, it is installed in a vehicle other than the electric vehicle 20, such as a hybrid vehicle having the same configuration as the electric vehicle 20 and an engine, or a fuel cell vehicle having the same configuration as the electric vehicle 20 and a fuel cell. It may be in the form of a power supply device, or may be in the form of a power supply device incorporated in equipment that does not move.

In the power supply device of the embodiment, the battery 36 is used as the power storage device, but instead of this, a capacitor may be used.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiment, the battery 36 corresponds to the "storage device", the DC/DC converter 48 corresponds to the "converter", the system main relay SMR corresponds to the "relay", and the ECU 70 corresponds to the "control device".

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention is applicable to the power supply manufacturing industry and the like.

20 electric vehicle 22a, 22b drive wheel 24 differential gear 26 drive shaft 32 motor 34 inverter 36 battery 36a voltage sensor 36b current sensor 38 high voltage power line 39 capacitor 39a voltage sensor 40 Auxiliary battery, 42 low-voltage power line, 48 DC/DC converter, 70 ECU, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal Position sensor, 87 vehicle speed sensor, SMR system main relay, SMRB positive side relay, SMRG negative side relay.

Claims (1)

a power storage device;
a converter capable of step-down operation for stepping down the power of the first power line to which the power storage device is connected and supplying the power to the second power line;
a positive side relay provided closer to the power storage device than the converter on the positive side line of the first power line; and a positive side relay provided closer to the power storage device than the converter on the negative side line of the first power line. a relay having a negative relay;
a control device that controls the converter and the relay with communication;
A power supply device comprising:
The converter performs a step-down operation when communication with the control device is interrupted,
When communication with the converter is interrupted and the positive electrode side relay and the negative electrode side relay are opened one by one, the control device opens the positive electrode side relay and the positive electrode side relay when communication with the converter was previously interrupted. Open the negative side relays one by one in the reverse order,
Power supply.

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