JP2007159326A - Power supply controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply a power supply controller which detects as quickly as possible such a failure as in a fusion bonding or the like of a relay in a power supply circuit of an electric automobile or the like, without delaying the start of travelling. <P>SOLUTION: This power supply controller is equipped with: relay control means (S200 to S208) which open the contact point of either a first relay or a second relay, when the contact points of a first and second relays (MC1, MC1) are closed and a stop direction of supply of power to an electric load is given, in the open state of the contact point of a third relay (PCC); and fault detection means (S212, S214, S230) which compare a detected terminal voltage V2 of a capacitor with a specified value Vref to detect whether either the first relay or the second relay is defective, based on the compared result, when the contact point of either relay is opened. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power supply control device, and more specifically to a power supply control device for an electric vehicle or a hybrid vehicle.

  In an electric vehicle or a hybrid vehicle (a vehicle having an internal combustion engine and a motor as a driving source), a large-capacity battery is provided and connected to an electric load such as an electric motor (motor) via a power supply circuit to supply electric power. Yes. A relay (electromagnetic relay) is inserted in the power supply circuit, and the power supply to the electric load is controlled by opening and closing the contact by exciting and demagnetizing the relay. Since the battery has a high voltage of 200 V or higher, the current flowing through the relay contacts also increases, which may cause a relay welding failure.

Therefore, as described in Patent Document 1 below, a technique for detecting relay welding has been proposed. In the technology, the first and second relays are connected to the power supply circuit between the positive and negative terminals of the battery and the electric load (motor), respectively, and the first relay is connected in parallel with a resistor. At least a third relay to which the contacts are connected, a capacitor connected in parallel with the electric load, and a controller that controls the supply of electric power to the electric load by opening and closing the contacts of the first to third relays. In addition, the terminal voltage of the capacitor when the relay is turned on and off when a command to start the supply of electric power to the electric load is issued, and then welding of the relay is detected.
JP 2000-134707 A

  In the above-described prior art, when a command to start supplying power to the electric load is issued, in other words, the welding of the relay is detected at the start of traveling, but a certain amount of time is required for charging the capacitor. Therefore, there is an inconvenience that it takes time to complete the detection and delays the start of traveling. Also, since welding of the relay is likely to occur when the relay is turned on and may also occur during traveling, if it is detected before the start of traveling, the welding that occurs when the relay is turned on or during traveling is detected. Detection is performed before the start of the next run.

  The present invention provides a power supply control device that eliminates the above-described disadvantages and detects a failure such as welding of a relay of a power circuit of an electric vehicle or the like as quickly as possible without delaying the start of traveling. is there.

  In order to solve the above-described object, in claim 1, a battery connected to an electric load via a power supply circuit to supply electric power to the electric load, a positive / negative terminal of the battery to the power supply circuit, and the battery First and second relays each having a contact connected between the electric loads, a third relay having a contact connected to the power supply circuit via a resistor in parallel with the first relay, and the power supply circuit A power supply control device comprising: a capacitor connected in parallel to the electrical load; and a control means for controlling the supply of power to the electrical load by opening and closing contacts of the first to third relays. A voltage sensor for detecting the terminal voltage of the power supply, and a command to stop the supply of electric power to the electric load in a state where the contacts of the first and second relays are closed and the contacts of the third relay are opened Gana A relay control means for opening one of the first and second relay contacts, and when the one relay contact is opened, the detected terminal voltage of the capacitor is set to a predetermined value. And a failure detecting means for detecting whether or not the one of the relays is in failure based on the comparison result.

  In the power supply control device according to claim 2, when the one relay is the first relay and no failure is detected, the contact of the second relay is opened, and then the third relay Relay control means for closing the contact of the relay, and when the contact of the third relay is closed, the detected terminal voltage of the capacitor is compared with a predetermined value, and the second relay is based on the comparison result A failure detection means for detecting whether or not there is a failure is provided.

  In the power supply control device according to claim 3, when the one relay is the first relay and when it is detected as a failure, the relay control means that opens the contact of the second relay, and the first relay And a failure detecting means for comparing the detected terminal voltage of the capacitor with a predetermined value when the contact of the second relay is opened, and detecting whether or not the second relay is failed based on the comparison result. did.

  In the power supply control device according to claim 4, when an instruction to start the supply of electric power to the electric load is given and the first and second relays are not detected to be faulty, the second Relay control means for closing the contact of the relay and then closing the contact of the third relay; and when the contact of the third relay is closed, the terminal voltage of the detected capacitor is compared with a predetermined value. In addition, the apparatus is configured to include failure detection means for detecting whether one of the first relay and the third relay is a failure based on the comparison result.

  In the power supply control device according to claim 5, when an instruction to supply electric power to the electric load is given and the first and third relays are not detected to be faulty, the first relay Relay control means for closing the contact of the third relay, and then opening the contact of the third relay, and when the contact of the third relay is opened, comparing the terminal voltage of the detected capacitor with a predetermined value, A failure detection means for detecting whether or not the first relay is failed based on the comparison result is provided.

  In the power supply control device according to claim 1, when a command to stop the supply of electric power to the electric load is issued, the contact of one of the first and second relays is opened, and the contact of one of the relays When the capacitor is opened, the detected terminal voltage of the capacitor is compared with a predetermined value, and based on the comparison result, it is configured to detect whether one of the relays is faulty or not. The accuracy can be improved. In addition, after the command to stop the supply of power to the electric load is made, in other words, the detection is made after the running is finished, so that the start of the running is not delayed, and the detection is made after the running is finished. When the welding of the relay occurs, it is possible to detect the welding earlier than when detecting the welding before the start of traveling.

  In the power supply control device according to claim 2, when one of the relays is the first relay and no failure is detected, the contact of the second relay is opened, and then the contact of the third relay is opened. Since it is closed and the contact of the third relay is closed, the detected terminal voltage of the capacitor is compared with a predetermined value, and based on the comparison result, it is configured to detect whether or not the second relay is faulty. In addition to the effects described above, it is possible to accurately detect failures such as welding of the second relay.

  In the power supply control device according to claim 3, when one of the relays is the first relay and a failure is detected, the contact of the second relay is opened and the contact of the second relay is opened. In this case, the detected terminal voltage of the capacitor is compared with a predetermined value, and based on the comparison result, it is configured to detect whether or not the second relay is faulty. Faults such as welding can be detected with high accuracy.

  In the power supply control device according to claim 4, when a command to start the supply of electric power to the electric load is given and the first and second relays are not detected to be faulty, the contacts of the second relay And then the contact of the third relay is closed, and when the contact of the third relay is closed, the detected terminal voltage of the capacitor is compared with a predetermined value, and the first relay is based on the comparison result. Therefore, in addition to the above-described effects, it is possible to accurately detect a failure such as disconnection of the first or third relay.

  In the power supply control device according to claim 5, when a command to supply electric power to the electric load is given and when the first and third relays are not detected to be faulty, the contact of the first relay is set. Then, the third relay contact is opened, and when the third relay contact is opened, the detected terminal voltage of the capacitor is compared with a predetermined value, and the first relay is based on the comparison result. Therefore, in addition to the above-described effects, it is possible to accurately detect a failure such as a disconnection of the first relay.

  The best mode for carrying out the power supply control device according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram generally showing a power supply control apparatus according to a first embodiment of the present invention.

  Reference numeral 10 in FIG. 1 indicates a battery or a power storage device. The battery 10 is a module in which a plurality of, for example, about 12 nickel-hydrogen (Ni-MH) batteries connected in series are connected in series via a main fuse 10a and a main SW (switch) 10b. Having a high voltage. The battery 10 is connected to an electric load (motor (electric motor), indicated as “MTR” in the figure) 12 via a power supply circuit 14, and supplies power to the motor 12. The battery 10 is mounted on an electric vehicle or a hybrid vehicle (not shown) and drives the motor 12.

  As illustrated, the motor 12 is connected to the battery 10 via a PDU (Power Drive Unit) 16. The motor 12 is a DC brushless motor, more specifically, an AC synchronous motor. The PDU 16 includes an inverter, converts direct current (electric power) supplied (discharged) from the battery 10 to three-phase alternating current and supplies it to the motor 12, and converts alternating current generated by the regenerative operation of the motor 12 into direct current. The battery 10 is supplied. The PDU 16 includes a D / V (downverter) 20, and the D / V 20 steps down the high voltage supplied from the battery 10 to about 12 V and supplies it to a load 22 such as another auxiliary machine.

  A current sensor 24 is connected to the battery 10 and produces an output proportional to the current charged or discharged from the battery 10. In the power supply circuit 14, the first voltage sensor 26 is connected to the positive terminal (positive electrode) and the negative terminal (negative electrode) of the battery 10, and an output V 1 proportional to the terminal voltage of the battery 10 is generated. Outputs of the current sensor 24 and the voltage sensor 26 are sent to an ECU (Electronic Control Unit; not shown) for battery management, where a remaining SOC (State of Charge) of the battery 10 is calculated.

  MC 1 (main contactor 1, first relay) whose contact is connected between the positive terminal of battery 10 and motor 12 is connected to power supply circuit 14, and the contact is connected between the negative terminal of battery 10 and motor 12. MC2 (main contactor 2, second relay) is connected, and in parallel with MC1, a PCC (precharge contactor, third relay) whose contact is connected via a resistor 30 is connected. MC1, MC2 and PCC are electrically connected to an ECU (electronic control unit) 32 comprising a microcomputer.

  MC1, MC2, and PCC have a large rated current (allowable current), and are therefore called contactors (electromagnetic contactors), but are basically relays (electromagnetic relays). By the way, the rated current of MC1 and MC2 is 200A, that of PCC is 20A. The resistance 30 of the PCC is about 12Ω.

  A capacitor 34 for smoothing the voltage is connected to the power supply circuit 14, more precisely, the PDU 22 connected thereto, in parallel with the motor 12, and a second voltage sensor 36 is connected to the capacitor 34. It produces an output V2 that is proportional to the terminal voltage (more generally the PDU voltage). The output of the second voltage sensor 36 is also input to the ECU 32.

  Information relating to the on / off state of the ignition switch 40 of the mounted vehicle is also input to the ECU 32. As will be described later, the ECU 32 closes the MC2 contact and then closes the PCC contact when the ignition switch 40 changes from the OFF state to the ON state, that is, when a command to start supplying power to the motor 12 is issued. Then, supply of electric power to the motor 12 is started. Next, when a predetermined time has elapsed, the contact of MC1 is closed, and then the contact of PCC is opened.

  The reason why the PCC contact is first closed on the positive terminal side of the power supply circuit 14 and the motor 12 is energized via the PCC is that the voltage of the battery 10 is high, so that a large inrush current flows at the start of energization of the motor 12. This is because the main fuse 10a may melt or a contactor such as MC1 may be welded. Therefore, after a predetermined time has elapsed when the inrush current ends, energization of the motor 12 is performed via MC1 and MC2.

  Further, when the ignition switch 40 changes from the on state to the off state, that is, when an instruction to stop the supply of power to the motor 12 is issued, the ECU 32 opens the contacts of MC1, MC2, and PCC accordingly. The supply of electric power to the motor 12 is stopped.

  Thus, since the energization from the battery 10 is a high voltage and a large current, a contact failure such as MC1 may cause a welding failure due to an arc generated between the contacts. In addition, contactors such as MC1 may be broken due to disconnection.

  Therefore, the ECU 32 detects a failure due to welding of the MC1 or the like according to the change of the ignition switch 40 from the on state to the off state, and also detects a failure due to the disconnection according to the off state from the off state. Since the ECU 32 needs to operate even when the ignition switch 40 is in an OFF state, a backup power source 42 is provided.

  Next, the above-described failure detection performed by the ECU 32, that is, the operation of the power supply control device according to this embodiment will be described.

  FIG. 2 is a main flow chart showing the processing.

  In the following explanation, it is determined whether or not the detection is OK in S10, that is, whether or not a failure due to welding or disconnection of MC1 can be detected, in other words, whether or not a failure has already been detected. Skip the subsequent processing.

  When the result in S10 is affirmative, the program proceeds to S12, in which it is determined whether the ignition switch 40 has changed from the off state to the on state, in other words, whether or not a command to start supplying power to the motor 12 has been issued. Proceeding to S14, detection of disconnection of MC1 or the like is executed. On the other hand, when the result in S12 is negative, the program proceeds to S16, in which it is determined whether or not the ignition switch 40 has changed from on to off, that is, whether or not a command to stop supplying power to the motor 12 has been issued. If so, the process proceeds to S18 to detect welding of MC1 or the like. If the result in S16 is negative, the subsequent processing is skipped.

  FIG. 3 is a sub-routine flowchart of disconnection detection in S14, and FIG. 4 is a time chart showing the processing.

  Explained below, in S100, it is determined whether or not the output V2 of the second voltage sensor 36 (the detected PDU voltage or the terminal voltage of the capacitor 34) exceeds a predetermined value Vref. Detection cannot be executed.

  Referring to FIG. 4, since the time of S100 is 0 in FIG. 4, since all contactors such as MC2 are turned off (contacts are opened), the PDU 16 is not energized, The output V2 of the second voltage sensor 36 should also be at or near zero. Therefore, when the sensor output V2 exceeds the predetermined value Vref set appropriately between zero and the value at the time of energization, some abnormality has occurred, so disconnection detection is not executed.

  On the other hand, when the result in S100 is negative, the process proceeds to S104, MC2 is turned on (the contact is closed), the process proceeds to S106, and it is determined whether time A (shown in FIG. 4) has elapsed. In step S108, the PCC is turned on (its contact is closed). Next, the routine proceeds to S110, where it is determined whether or not the time B (shown in FIG. 4) has elapsed. If the determination is affirmative, the routine proceeds to S112, where it is determined whether the sensor output V2 exceeds a predetermined value Vref.

  As shown in FIG. 4, since MC2 and PCC are on at time B, the PDU 16 is energized and the output V2 should exceed Vref. Therefore, when the result in S112 is affirmative, it is determined that there is no disconnection and the process proceeds to S114, and MC1 is turned on (its contact is closed). As a result, the voltage applied to the input side of the PDU 16 becomes almost equal to the power supply voltage as a result of the electric charge being stored in the capacitor 34, so the MC1 is turned on. Next, the process proceeds to S116, where it is determined whether or not the time C has elapsed. If the determination is affirmative, the process proceeds to S118, where the PCC is turned off (its contact is opened).

  Next, the process proceeds to S120, in which it is determined whether or not the time D has elapsed. When the result is affirmed, the process proceeds to S122. When the sensor output V2 exceeds Vref, the process proceeds to S124. That is, it is determined that MC1, MC2, and PCC are not disconnected (no failure due to disconnection).

  On the other hand, when the result in S122 is negative, the process proceeds to S126, and MC1 is determined (detected) as disconnected (there is a failure due to disconnection). This is because the sensor output V2 is determined to exceed Vref (in response to the PCC being turned on) in the process of S112 (process at time B in FIG. 4). This is because MC1 is not turned on and in other words it can be determined that a disconnection has occurred.

  When the result in S112 is negative, the program proceeds to S128, and it is determined (detected) that either MC2 or PCC is disconnected. That is, as shown in FIG. 4, at time B, MC2 and PCC are turned on and the PDU 16 is energized, so the output V2 should exceed Vref. Nevertheless, when the result in S112 is negative, it can be determined that either MC2 or PCC (or both) is disconnected and not turned on.

  Next, in S130, all contactors are turned off and the control of the motor 12 is stopped. The same applies when the process proceeds to S126.

  The disconnection of MC1 or the like specifically means that any of the wiring such as the coil, the main contact, or the auxiliary contact is disconnected, and as a result, the contact is not closed (turned on).

  FIG. 5 is a sub-routine flow chart of the welding detection in S18, and FIG. 6 is a time chart showing the processing.

  Explaining below, in S200, it is determined whether or not the sensor output V2 (the detected PDU voltage or the terminal voltage of the capacitor 34) exceeds the predetermined value Vref. To do.

  Referring to FIG. 6, since the time of determination in S200 is time 0 in FIG. 6, since MC1 and MC2 are turned on, the PDU 16 should be energized. Accordingly, when the output V2 does not exceed the predetermined value Vref, some abnormality has occurred, so that the process proceeds to S202 and the welding detection is not performed, and then the process proceeds to S204 and all contactors (MC1, MC2, PCC). And the control of the motor 12 is stopped.

  On the other hand, when the result in S200 is affirmative, the process proceeds to S206, where it is determined whether or not the time a (shown in FIG. 6) has elapsed. When the result is affirmative, the process proceeds to S208 to turn off MC1 (open the contact). Proceeding to S210, it is determined whether or not time b (shown in FIG. 6) has elapsed. If affirmative, the process proceeds to S212, where it is determined whether or not the sensor output V2 exceeds a predetermined value Vref.

  As shown in FIG. 6, since MC1 and PCC are turned off at time b, the PDU 16 is not energized, the charge is discharged from the capacitor 34, and the sensor output V2 should not exceed Vref. Accordingly, when the result in S212 is negative, the program proceeds to S214, where it is determined that MC1 is normal (no welding) and is turned off as instructed in S208.

  Next, the process proceeds to S216, MC2 is turned off (the contact is opened), the process proceeds to S218, and it is determined whether or not time c has elapsed. If the determination is affirmative, the process proceeds to S220, and the PCC is turned on (the contact is closed). .

  Next, the routine proceeds to S222, in which it is determined whether or not the time d has passed. If the determination is affirmative, the processing proceeds to S224, and whether the sensor output V2 exceeds Vref is determined. If the determination is negative, the processing proceeds to S226, and MC2 is normal. It is determined that there is no welding.

  On the other hand, when negative in S224, the process proceeds to S228, and MC2 is determined to be welded (detected). Although MC2 should have been turned off immediately after time b in FIG. 6, it is determined that V2 exceeds Vref according to PCC on at time c because MC2 is turned off. This is because it can be determined that V2 is increased in response to the PCC being turned on as shown in the drawing, in other words, MC2 is welded, that is, it is determined that a failure has occurred where the contacts are welded and are not opened (turned off).

  When the result in S212 is affirmative, the program proceeds to S230, and MC1 is determined to be welded (detected). That is, as shown in FIG. 6, since only MC2 is turned on at time b and the PDU 16 is not energized, the output V2 should not exceed Vref. Nevertheless, if the result in S212 is affirmative, it can be determined that MC1 is welded and kept on.

  Next, the process proceeds to S232, MC2 is turned off (the contact is opened), the process proceeds to S234, and it is determined whether or not the time c has elapsed. When the determination is affirmative, the process proceeds to S236, and the output V2 is the same as the process after S224. It is determined whether or not Vref is exceeded. When the result in S236 is negative, the process proceeds to S238, and it is determined that MC2 is normal (no welding). When the result is positive, the process proceeds to S240, and MC2 is determined (detected) as welding. This is because, as described above, although MC2 should have been turned off immediately after time b in FIG. 6, it can be determined that MC2 is welded because V2 is determined to exceed Vref. It is.

  Next, in S204, all contactors are turned off and the control of the motor 12 is stopped. In the processing from S208 to S212, MC1 is first turned off to detect the failure. However, MC2 may be turned off first to detect the failure.

  In this embodiment, as described above, a battery 10 connected to an electric load (motor 12, more specifically, PDU 16) via a power supply circuit 14 to supply power to the electric load, and the power supply circuit The first and second relays (MC1 and MC2) are connected to the battery between the positive and negative terminals of the battery and the electric load, respectively, and the power supply circuit has a contact through a resistor in parallel with the first relay. A third relay (PCC) to be connected, a capacitor 34 connected to the power supply circuit in parallel with the electrical load, and contacts of the first to third relays (MC1, MC2) are opened and closed to open the electrical circuit. In a power supply control device including a control means (ECU 32) for controlling supply of power to a load, a voltage sensor (second voltage sensor) 36 for detecting a terminal voltage of the capacitor, the first and second relays. When the contact of (MC1, MC2) is closed and the stop of power supply to the electric load is issued in the state where the contact of the third relay (PCC) is open, the first, Relay control means (ECU 32, S200 to S208) for opening a contact of one relay (for example, MC1) of the second relays (MC1, MC2), and the detection when the contact of the one relay is opened The capacitor terminal voltage V2 is compared with a predetermined value Vref, and based on the comparison result, it is configured to include failure detection means (ECU32, S212, S214, S230) for detecting whether or not one of the relays has failed.

  As described above, when an instruction to stop the supply of electric power to the electric load is made, the contact of one of the first and second relays (for example, MC1) is opened, and the contact of one of the relays is opened. The sensor output V2 is compared with the predetermined value Vref, and based on the comparison result, it is configured to detect whether one of the relays is faulty. Therefore, it is possible to accurately detect faults such as welding of relays such as MC1 of the power circuit 14. can do. In addition, after the command to stop the supply of power to the electric load is made, in other words, the detection is made after the running is finished, so that the start of the running is not delayed, and the detection is made after the running is finished. When the welding of the relay occurs, it is possible to detect the welding earlier than when detecting the welding before the start of traveling.

  Further, when the one relay is the first relay (MC1) and no failure is detected, the contact of the second relay (MC2) is opened, and then the third relay (PCC) When the contact of the relay control means (ECU 32, S216 to S220) for closing the contact and the contact of the third relay (PCC) is closed, the detected terminal voltage V2 of the capacitor is compared with a predetermined value Vref and compared. Based on the result, a failure detection means (ECU 32, S222 to S228) for detecting whether or not the second relay (MC2) is in failure is provided.

  In this way, when one of the relays is the first relay (MC1) and no failure is detected, the contact of the second relay (MC2) is opened, and then the contact of the third relay (PCC) is opened. When the contact of the third relay (PCC) is closed and the contact of the third relay (PCC) is closed, the detected terminal voltage of the capacitor is compared with a predetermined value, and whether or not the second relay (MC2) has failed based on the comparison result. Since it is configured to detect, in addition to the above-described effects, it is possible to accurately detect a failure such as welding of the second relay (MC2).

  Relay control means (ECU32, S230, S232) for opening the contact of the second relay (MC2) when the one relay is the first relay (MC1) and is detected as a failure; When the contact of the second relay is opened, the detected terminal voltage V2 of the capacitor is compared with a predetermined value Vref, and it is detected whether or not the second relay (MC2) is out of order based on the comparison result. The apparatus is configured to include failure detection means (ECU 32, S234 to S240).

  Thus, when one of the relays is the first relay (MC1) and a failure is detected, the contact of the second relay (MC2) is opened and the contact of the second relay (MC2) is opened. In this case, the detected terminal voltage of the capacitor is compared with a predetermined value, and based on the comparison result, it is configured to detect whether or not the second relay (MC2) is out of order. It is possible to accurately detect a failure such as welding of the relay (MC2).

  Further, when a command to start the supply of electric power to the electric load is issued and when the first and second relays (MC1, MC2) are not detected as a failure, the contact of the second relay (MC2) And then the relay control means (ECU 32, S100 to S108) for closing the contact of the third relay (PCC), and the detection when the contact of the third relay (PCC) is closed A failure detection means (ECU 32) compares the terminal voltage V2 of the capacitor with a predetermined value Vref and detects whether one of the first relay (MC1) and the third relay (PCC) is a failure based on the comparison result. , S110, S112, S128).

  As described above, when a command to start the supply of electric power to the electric load is issued, and when the first and second relays (MC1, MC2) are not detected as malfunctioning, the contact of the second relay (MC2) is set. And then closing the contact of the third relay (PCC). When the contact of the third relay (PCC) is closed, the detected terminal voltage of the capacitor is compared with a predetermined value, and based on the comparison result In addition to the effects described above, the first or third relay (MC1) or the third relay (PCC) is configured to detect whether or not a failure has occurred. It can be detected with high accuracy.

  In addition, when a command to supply power to the electric load is issued and the first and third relays (MC1, PCC) are not detected as malfunctioning, the contact of the first relay (MC1) is set. Relay control means (ECU 32, S114 to S118) for closing and then opening the contact of the third relay (PCC), and the detected terminal voltage of the capacitor when the contact of the third relay is opened V2 is compared with a predetermined value vref, and a failure detection means (ECU 32, S120 to S126) for detecting whether or not the first relay is failed based on the comparison result is provided.

  As described above, when the power supply to the electric load is instructed, and when the first and third relays (MC1, PPC) are not detected as malfunctioning, the contact of the first relay (MC1) is closed. Then, the contact of the third relay (PCC) is opened, and when the contact of the third relay is opened, the detected terminal voltage of the capacitor is compared with a predetermined value, and the first based on the comparison result Therefore, in addition to the above-described effects, it is possible to detect a failure such as a disconnection of the first relay with high accuracy.

  In the above description, a battery made of a nickel metal hydride battery has been described as an example of the battery. However, the battery is not limited to this, and may be a battery made of another battery, or may be a power storage means other than a battery such as a capacitor. .

1 is a schematic diagram showing the overall configuration of a power supply control device according to a first embodiment of the present invention. 1 is a main flow chart showing the operation of the apparatus. 3 is a sub-routine flow chart showing disconnection detection in the flow chart. 3 is a time chart for explaining the processing shown in the flow chart. 2 is a sub-routine flow chart showing welding detection in the flow chart. 6 is a time chart for explaining the processing shown in the flow chart of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Battery, 12 Motor (electric motor, electric load), 14 Power supply circuit, 16 Power drive unit (PDU, electric load), 32 Electronic control unit (ECU), 34 Capacitor, 36 2nd voltage sensor, 40 Ignition switch

Claims (5)

A battery connected to an electric load via a power supply circuit to supply power to the electric load, and first and second contacts connected to the power supply circuit between positive and negative terminals of the battery and the electric load, respectively. A relay, a third relay having a contact connected to the power circuit in parallel with the first relay via a resistor, a capacitor connected to the power circuit in parallel with the electrical load, In a power supply control device comprising a control means for controlling the supply of electric power to the electric load by opening and closing a contact of a third relay,
a. A voltage sensor for detecting a terminal voltage of the capacitor;
b. When the first and second relay contacts are closed and the third relay contact is open, an instruction to stop power supply to the electric load is issued. Relay control means for opening a contact of one of the second relays;
And c. A failure detection means for comparing the detected terminal voltage of the capacitor with a predetermined value when the contact of the one of the relays is opened, and detecting whether the one of the relays is faulty based on a comparison result;
A power supply control device comprising: d. Relay control means for opening the contact of the second relay and then closing the contact of the third relay when the one relay is the first relay and is not detected as a failure;
And e. A failure detecting means for comparing the detected terminal voltage of the capacitor with a predetermined value when the contact of the third relay is closed, and detecting whether or not the second relay is failed based on a comparison result;
The power supply control device according to claim 1, further comprising: f. Relay control means for opening the contact of the second relay when the one relay is the first relay and is detected as a failure;
And g. A failure detecting means for comparing the detected terminal voltage of the capacitor with a predetermined value when the contact of the second relay is opened, and detecting whether or not the second relay is failed based on a comparison result;
The power supply control device according to claim 1, further comprising: h. When a command to start supplying power to the electric load is issued, and when the first and second relays are not detected to be faulty, the contact of the second relay is closed, and then the third relay Relay control means for closing the contacts of the
And i. When the contact of the third relay is closed, the detected terminal voltage of the capacitor is compared with a predetermined value, and one of the first relay and the third relay is failed based on the comparison result. Failure detection means for detecting whether or not,
The power supply control device according to claim 1, further comprising: j. When a command to supply power to the electrical load is issued and the first and third relays are not detected to be faulty, the contacts of the first relay are closed, and then the third relay Relay control means for opening the contacts,
And k. A failure detecting means for comparing the detected terminal voltage of the capacitor with a predetermined value when the contact of the third relay is opened, and detecting whether or not the first relay is failed based on a comparison result;
The power supply control device according to claim 4, further comprising:

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