JP2011101469A - Power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more appropriately cope with disconnection requests than in conventional systems, even if it is made while a capacitor installed on a power line is charged in a power supply system using a system main relay low in tolerance. <P>SOLUTION: When a disconnection request for electrically disconnecting a direct-current power supply and equipment is made while a capacitor is charged to start power supply from the direct-current power supply to the equipment, processing is carried out as follows: after charging the capacitor is completed, a relay SMRG is turned off, a relay SMRB is turned off to turn off the system main relay, and the direct-current power supply and the load are thereby electrically disconnected from each other. As a result, a low-tolerance system main relay 30 can be used, resulting in cost reduction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power supply system, and more particularly, to a power supply system that supplies power from a DC power supply to a device.

  Conventionally, this type of power supply system is set in advance in a power supply system mounted on a vehicle when an abnormality occurs in the communication line when the system main relay is requested to be cut off by turning off the ignition switch. It has been proposed to turn off the system main relay after the lapsed delay time has elapsed (see, for example, Patent Document 1). In this system, a necessary evacuation operation by the drive system or the like is executed until the delay time elapses.

JP 2008-195255 A

  However, in the above-described power supply system, if a disconnection request is made when no abnormality has occurred in the communication line, the system main relay is immediately turned off. Therefore, depending on the timing at which the disconnection request is made, the system main relay has higher tolerance. There is a need to seek. In a power supply system, when starting to supply DC power to a device, it is common to charge a capacitor attached to a power line and then start supplying DC power to the device. If the system main relay is turned off due to a disconnection request while charging such a capacitor, it is necessary to use a system main relay that can cope with this because the arc-free opening is not achieved.

  The power supply system of the present invention is a power supply system using a system main relay with low tolerance, and is intended to more appropriately cope with a request to shut off while charging a capacitor attached to a power line. And

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

The power supply system of the present invention is
A power supply system that supplies power from a DC power supply to a device,
A capacitor attached to a power line from the DC power source to the device;
A first relay attached to the DC power supply side from the capacitor of the power line and attached to a positive side line or a negative side line of the power line, and a negative side line or a negative side line of the power line A charging circuit in which a second relay attached to a line different from the line to which the first relay is attached, a third relay and a resistor are connected in series, and connected in parallel to the second relay And a system main relay that electrically connects and disconnects the DC power source and the device, and
While the capacitor is being charged while the third relay is turned on and the first relay is turned on and the second relay is turned off, the DC power supply and the device are electrically disconnected. When requested, after the capacitor is fully charged and the second relay is turned on, the first relay, the second relay, and the third relay are turned off to electrically connect the DC power supply and the device. Control means for controlling the system main relay so as to shut off,
It is a summary to provide.

  In the power supply system of the present invention, the DC power supply and the device are charged while the capacitor is being charged with the third relay of the system main relay turned on, the first relay turned on, and the second relay turned off. When the electrical disconnection is requested, the charging of the capacitor is completed and the second relay is turned on, and then the first relay, the second relay, and the third relay are turned off to electrically connect the DC power supply and the device. Control system main relay to shut off. That is, the capacitor is cut off after charging is completed. Thereby, it can open | release without an electric arc and can interrupt | block more appropriately even if it uses a system main relay with low tolerance.

It is a block diagram which shows the outline of a structure of the power supply system 20 as one Example of this invention. It is a flowchart which shows an example of the charge control routine performed by the electronic control unit 40 of an Example. It is explanatory drawing which shows an example of the time change of relay SMRB, relay SMRP, relay SMRG, electric current I, and ignition when the interruption | blocking request | requirement is made during the charge of the capacitor | condenser 26. FIG.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a power supply system 20 as an embodiment of the present invention. The power supply system 20 according to the embodiment is configured as a system that is mounted on, for example, an electric vehicle or a hybrid vehicle and supplies power from a DC power supply 22 such as a secondary battery to a device 10 such as a running motor. The capacitor 26 attached to the power lines 24a and 24b from the system, the system main relay 30 attached to the DC power supply 22 side from the capacitor 26, and the electronic control unit 40 for controlling the system main relay 30 are provided.

  System main relay 30 is connected in series with relay SMRB attached to the positive line of power lines 24a and 24b and relay SMRG attached to the negative line of power lines 24a and 24b. The charging circuit 36 includes a relay SMRP and a resistor 38 and is connected in parallel to the relay SMRG with respect to the power line 24b. The drive coils of relay SMRB, relay SMRG, and relay SMRP of system main relay 30 are all connected to electronic control unit 40, and can be turned on / off by electronic control unit 40.

  The electronic control unit 40 is configured as a microprocessor centered on the CPU 42, and includes a ROM 44 for storing a processing program, a RAM 46 for temporarily storing data, and an input / output port (not shown) in addition to the CPU 42. The electronic control unit 40 is input with an ignition signal from the ignition switch 50, a current I from the current sensor 52 attached to the power line 24a, and the like through an input port. The electronic control unit 40 outputs drive currents for the relay SMRB, the relay SMRG, and the relay SMRP of the system main relay 30. When the ignition switch 50 is turned on, the electronic control unit 40 turns on the system main relay 30 so that power can be supplied from the DC power source 22 to the device 10 and the ignition switch 50 is turned on. When turned off, the system main relay 30 is turned off and the DC power supply 22 and the device 10 are electrically disconnected, assuming that a disconnection request has been made.

  Next, the operation of the power supply system 20 configured as described above, particularly the operation when a cutoff request is made when the capacitor 26 is charged before starting the power supply to the device 10 will be described. FIG. 2 is a flowchart showing an example of a charge control routine executed by the electronic control unit 40. This routine is executed when a connection request is made, such as when the ignition switch 50 is turned on.

  When the charge control routine is executed, the CPU 42 of the electronic control unit 40 first turns on the relay SMRB attached to the positive power line 24a among the relays of the system main relay 30 (step S100), and the charge is performed. The relay SMRP of the circuit 36 is turned on (step S110), and charging of the capacitor 26 is started. Then, even if an interruption request is made, the rejection of acceptance of the interruption request is memorized so as to reject it (step S120), and the current I from the current sensor 52 falls below a threshold value Iref that can be considered to be complete. Wait (steps S130 and S140). In the embodiment, when the rejection of acceptance of the interruption request is stored, the system main relay 30 is not turned off even if the interruption request is made due to turning off the ignition switch 50 or the like. As a result, the capacitor 26 continues to be charged even if a cutoff request is made.

  When the current I reaches less than the threshold value Iref, the relay SMRG attached to the negative power line 24b is turned on (step S150), the relay SMRP of the charging circuit 36 is turned off (step S160), and the capacitor 26 is turned on. It is determined whether or not a shut-off request is made during charging (step S170). If the shut-off request is not made, this routine is terminated as it is. On the other hand, when a disconnection request is made while charging the capacitor 26, the relay SMRG attached to the negative power line 24b is turned off (step S180) and attached to the positive power line 24a. By turning off relay SMRB (step S190), system main relay 30 is turned off, DC power supply 22 and device 10 are electrically disconnected, and this routine is terminated.

  FIG. 3 shows an example of changes over time of relay SMRB, relay SMRP, relay SMRG, current I, and ignition of system main relay 30 when a cutoff request is made by turning off ignition switch 50 while capacitor 26 is being charged. Show. When the ignition switch 50 is turned on at time T1, the relay SMRB attached to the positive power line 24a is turned on and the relay SMRP of the charging circuit 36 is turned on to start charging the capacitor 26. Is done. Even when the ignition switch 50 is turned off at time T2, which is the timing before the capacitor 26 is fully charged, and the disconnection request is made, the capacitor 26 is being charged. Charging continues. At time T3 when the current I reaches less than the threshold value Iref, it is determined that charging of the capacitor 26 is completed, the relay SMRG attached to the negative power line 24b is turned on, and the relay SMRP of the charging circuit 36 is turned on. Is turned off, and charging of the capacitor 26 is completed. Since the cutoff request is made during charging of the capacitor 26, the relay SMRG attached to the negative power line is turned off and the relay SMRB attached to the positive power line 24a is turned off at time T4. The system main relay 30 is turned off to electrically disconnect the DC power supply 22 and the device 10. At this time, since no current flows, the relay SMRG is turned off and the system main relay 30 is turned off by turning off the relay SMRB, so that the arc power source is opened without applying a load to each relay. Can be blocked.

  According to the power supply system 20 of the embodiment described above, the DC power supply 22 and the device 10 are electrically disconnected while the capacitor 26 is being charged in order to start supplying power from the DC power supply 22 to the device 10. When the cutoff request is made, after charging of the capacitor 26 is completed, the relay SMRG is turned off and the relay SMRB is turned off to turn off the system main relay 30 to electrically cut off the DC power supply 22 and the device 10. Therefore, the electrical disconnection between the DC power supply 22 and the device 10 can be made open without arc, and the DC power supply 22 and the device 10 can be electrically disconnected without imposing a burden on each relay. As a result, a system main relay 30 with low tolerance can be used, and the cost can be reduced. That is, even when the system main relay 30 having low tolerance is used, it is possible to cope with the situation more appropriately when a cutoff request is made while the capacitor 26 is being charged.

  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 problems will be described. In the embodiment, the capacitor 26 corresponds to a “capacitor”, the relay SMRB corresponds to a “first relay”, the relay SMRG corresponds to a “second relay”, the relay SMRP corresponds to a “third relay”, The resistor 38 corresponds to the “resistor”, the charging circuit 36 corresponds to the “charging circuit”, the system main relay 30 corresponds to the “system main relay”, and power supply from the DC power supply 22 to the device 10 is started. Therefore, when a request to shut off the DC power supply 22 and the device 10 is made while the capacitor 26 is being charged, the relay SMRG is turned off and the relay SMRB after the capacitor 26 has been charged. 2 is executed to turn off the system main relay 30 to electrically disconnect the DC power supply 22 and the device 10 from each other. The electronic control unit 40 corresponds to a "control 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 column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the power supply system manufacturing industry.

  10 equipment, 20 power supply system, 22 DC power supply, 24a, 24b power line, 26 capacitor, 30 system main relay, 36 charging circuit, 38 resistance, 40 electronic control unit, 42 CPU, 44 ROM, 46 RAM, 50 ignition switch , 52 Current sensor, SMRB, SMRG, SMRP relay.

Claims (1)

A power supply system that supplies power from a DC power supply to a device,
A capacitor attached to a power line from the DC power source to the device;
A first relay attached to the DC power supply side from the capacitor of the power line and attached to a positive side line or a negative side line of the power line, and a negative side line or a negative side line of the power line A charging circuit in which a second relay attached to a line different from the line to which the first relay is attached, a third relay and a resistor are connected in series, and connected in parallel to the second relay And a system main relay that electrically connects and disconnects the DC power source and the device, and
While the capacitor is being charged while the third relay is turned on and the first relay is turned on and the second relay is turned off, the DC power supply and the device are electrically disconnected. When requested, after the capacitor is fully charged and the second relay is turned on, the first relay, the second relay, and the third relay are turned off to electrically connect the DC power supply and the device. Control means for controlling the system main relay so as to shut off,
Power supply system comprising.

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