JP2015149874A - Power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that when a switch element connected with an excitation coil for driving a relay fails while being turned on, a current flows continuously to the excitation coil, and thereby a power storage device and a load remain to be connected.SOLUTION: A relay connects a power storage device and a load during electrification of an excitation coil, and interrupts connection of the storage device and the load during non-electrification of the excitation coil. A first switch element is switched between ON for allowing electrification of an excitation coil, and OFF for interrupting electrification of the excitation coil. A current interruption circuit has a second switch element for interrupting electrification of the excitation coil, when the voltage level of the power storage element detected using a voltage detection line is higher than a threshold. A controller controls the first switch element and second switch element, respectively. Consequently, even if the first switch element fails in the ON state, the controller controls the second switch element to interrupt electrification of the excitation coil, and connection of the power storage device and the load can be interrupted.

Description

  The present invention relates to a circuit for driving a relay for connecting a power storage device and a load.

  In Patent Document 1, the system main relay is switched from OFF to ON by turning on the switch and passing a current through the exciting coil. When the system main relay is on, the battery is connected to the drive device.

JP 2013-223330 A

  If a failure occurs while the switch is on, current continues to flow through the exciting coil, and the system main relay remains on.

  The power storage system of the present invention includes a power storage device, a relay, a first switch element, a current interrupt circuit, and a controller. The power storage device includes a plurality of power storage elements that are electrically connected in series. The relay connects the power storage device to the load when the excitation coil is energized, and disconnects the connection between the power storage device and the load when the excitation coil is not energized. The first switch element switches between ON that allows energization of the exciting coil and OFF that interrupts energization of the exciting coil. The current cutoff circuit includes a second switch element that cuts off the energization of the exciting coil when the voltage value of the storage element detected using the voltage detection line is higher than a threshold value. The controller controls each of the first switch element and the second switch element.

  According to the present invention, even if the first switch element is in an on state, the controller can control the second switch element to cut off the energization of the exciting coil. Thereby, even if a 1st switch element fails, the connection of an electrical storage apparatus and load can be interrupted | blocked.

It is a figure which shows the structure of a battery system. It is a figure which shows the structure of a current interruption circuit. In Example 1, it is a figure which shows the circuit which drives a system main relay. 5 is a flowchart illustrating processing for determining a failure of a circuit that drives a system main relay in the first embodiment. In Example 2, it is a figure which shows the circuit which drives a system main relay. 9 is a flowchart illustrating processing for determining a failure of a circuit that drives a system main relay in the second embodiment. In Example 3, it is a figure which shows the circuit which drives a system main relay. 10 is a flowchart illustrating processing for determining a failure of a circuit that drives a system main relay in the third embodiment.

  Examples of the present invention will be described below.

  FIG. 1 is a diagram showing a configuration of a battery system of the present embodiment (corresponding to the power storage system of the present invention).

  The assembled battery (corresponding to the power storage device of the present invention) 10 has a plurality of unit cells (corresponding to the power storage element of the present invention) 11 electrically connected in series. As the cell 11, a secondary battery or an electric double layer capacitor can be used. The assembled battery 10 is connected to the load 20 via the positive electrode line PL and the negative electrode line NL. The load 20 operates by receiving the discharge power of the assembled battery 10 or generates power for charging the assembled battery 10. When the battery system of this embodiment is mounted on a vehicle, a motor / generator can be used as the load 20.

  A system main relay SMR-B is provided in the positive electrode line PL, and a system main relay SMR-G is provided in the negative electrode line NL. System main relays SMR-B and SMR-G are switched between on and off in response to a control signal from controller 40.

  The voltage sensor 31 detects the voltage value VB of the assembled battery 10 and outputs the detection result to the controller 40. A capacitor (smoothing capacitor) C1 is connected to the positive electrode line PL and the negative electrode line NL. The voltage sensor 32 detects the voltage value VL of the capacitor C1 and outputs the detection result to the controller 40.

  As shown in FIG. 2, a current interrupt circuit 50 is connected to the assembled battery 10 via a voltage detection line L1. The current cut-off circuit 50 is used to cut off the connection between the assembled battery 10 and the load 20 when the unit cell 11 is in an overcharged state. Specifically, when the cell 11 is in an overcharged state, the current interrupt circuit 50 switches the system main relays SMR-B and SMR-G from on to off.

  The current interrupt circuit 50 includes a resistor R1, and the resistor R1 is provided in each voltage detection line L1. The resistor R1 is used to prevent an overvoltage from the assembled battery 10 (unit cell 11) from being applied to the current interrupt circuit 50. That is, when an overvoltage is to be applied to the current interrupt circuit 50, the resistor R1 is blown to prevent the overvoltage from being applied to the current interrupt circuit 50.

  The current interrupt circuit 50 includes a plurality of Zener diodes D. Each zener diode D is electrically connected in parallel with each unit cell 11 via a voltage detection line L1. Here, the cathode of the Zener diode D is connected to the positive terminal of the single battery 11, and the anode of the Zener diode D is connected to the negative terminal of the single battery 11. The plurality of Zener diodes D are electrically connected in series.

  The Zener diode D is used to suppress application of an overvoltage from the assembled battery 10 (unit cell 11) to the current interrupt circuit 50. That is, when an overvoltage is to be applied to the current interrupt circuit 50, the Zener diode D becomes conductive, so that a current can flow from the cathode to the anode. Thereby, it can suppress that an overvoltage is applied to the IC (Integrated Circuit) 51 side mentioned later.

  When the Zener diode D becomes conductive, the resistor R1 can be blown by passing a current through the resistor R1. That is, when an overvoltage is to be applied from the assembled battery 10 to the IC 51, the connection between the assembled battery 10 and the IC 51 can be interrupted by fusing the resistor R <b> 1. Thereby, the IC 51 can be protected. Note that the Zener diode D can be omitted if the application of the overvoltage to the current interrupt circuit 50 can be excluded.

  The current interrupt circuit 50 includes a capacitor C2. One end of the capacitor C2 is connected to the voltage detection line L1, and the other end of the capacitor C2 is grounded. The capacitor C2 is provided for each voltage detection line L1, and is used to reduce noise in the voltage detection line L1. A connection point of the capacitor C2 to the voltage detection line L1 is located between an IC 51 described later and a connection point of the Zener diode D to the voltage detection line L1. If the influence of noise can be ignored, the capacitor C2 can be omitted.

  The current interruption circuit 50 has an IC 51. The IC 51 receives a start signal or a stop signal from the controller 40. The activation signal is a signal that allows power from a power source (not shown) to be supplied to the IC 51, and the IC 51 can be operated by the activation signal. The stop signal is a signal for stopping power supply from the power source to the IC 51, and the operation of the IC 51 can be stopped by the stop signal.

  The IC 51 has a comparator CMP. The voltage detection line L1 connected to the positive terminal of each unit cell 11 is connected to the negative input terminal of the comparator CMP. In addition, the voltage detection line L1 connected to the negative terminal of each unit cell 11 is connected to the positive input terminal of the comparator CMP.

  Here, as shown in FIG. 2, the voltage detection line L1 connected to the positive terminal of one unit cell 11 and the negative terminal of the other unit cell 11 is branched. The branched voltage detection line L1 is connected to the positive input terminal of one comparator CMP and the negative input terminal of the other comparator CMP.

  The comparator CMP outputs the potential difference between the positive electrode terminal and the negative electrode terminal in the unit cell 11, in other words, the voltage value of the unit cell 11. The IC 51 has an OR circuit 52 connected to the comparator CMP, and an output signal from the comparator CMP is input to the OR circuit 52. The OR circuit 52 is connected to a plurality of comparators CMP, and when an output signal of any one of the comparators CMP is input to the OR circuit 52, the OR circuit 52 generates an output signal.

  In the present embodiment, the plurality of comparators CMP operate at different timings. That is, output signals from the plurality of comparators CMP are input to the OR circuit 52 at different timings. For this reason, every time the voltage value of each cell 11 is detected, the OR circuit 52 outputs a signal corresponding to this voltage value.

  The IC 51 has an alarm confirmation circuit 53 connected to the OR circuit 52, and an output signal of the OR circuit 52 is input to the alarm confirmation circuit 53. The alarm confirmation circuit 53 determines the overcharge state of the unit cell 11, and outputs an alarm signal when the unit cell 11 is in the overcharge state. The alarm signal is a signal indicating that the unit cell 11 is in an overcharged state.

  The alarm confirmation circuit 53 can be configured by a comparator. The output signal of the OR circuit 52 (the voltage value of the unit cell 11) is input to the negative input terminal of the alarm determination circuit (comparator) 53. The threshold value (voltage value) V_th is input to the positive input terminal of the alarm determination circuit (comparator) 53.

  The threshold value (voltage value) V_th is a voltage value for determining the overcharge state of the unit cell 11 and can be appropriately set in consideration of the charge / discharge characteristics of the unit cell 11 and the like. For example, the threshold value (voltage value) V_th is set to a voltage value when the cell 11 is actually overcharged, or a value lower than the voltage value when the cell 11 is actually overcharged. Can be set.

  When the output signal of the OR circuit 52 (voltage value of the single cell 11) is higher than the threshold value (voltage value) V_th, the output signal (alarm signal) of the alarm determination circuit (comparator) 53 is generated. On the other hand, when the output signal of the OR circuit 52 (voltage value of the single battery 11) is lower than the threshold value (voltage value) V_th, the output signal (alarm signal) of the alarm determination circuit (comparator) 53 is not generated.

  The IC 51 has an alarm latch circuit 54 connected to the alarm confirmation circuit 53, and an output signal (alarm signal) of the alarm confirmation circuit 53 is input to the alarm latch circuit 54. The alarm latch circuit 54 holds the input signal from the alarm confirmation circuit 53 and outputs a latch signal (corresponding to an alarm signal).

  The IC 51 (alarm latch circuit 54) is connected to the photocoupler 55. The photocoupler 55 is used as a switch element, and switches from off to on by receiving a latch signal from the alarm latch circuit 54. Since the photocoupler 55 is an insulating element, the circuit located on the input side of the photocoupler 55 (high voltage circuit) and the circuit located on the output side of the photocoupler 55 (low voltage circuit) are insulated. Can do. In other words, the photocoupler 55 can convert a high voltage signal as an input signal into a low voltage signal as an output signal.

  The photocoupler 55 is connected to the OR circuit 56. When the photocoupler 55 is switched from OFF to ON, the output signal of the photocoupler 55 is input to the OR circuit 56. As a result, an output signal is generated from the OR circuit 56, and this output signal is input to the switch element 57 (SW, which corresponds to the second switch element of the present invention). The switch element 57 receives the output signal of the OR circuit 56 and switches from on to off. Here, when the output signal of the OR circuit 56 is not input to the switch element 57, the switch element 57 is turned on.

  An output signal from the controller 40 is input to the OR circuit 56. When the output signal of the controller 40 is input to the OR circuit 56, an output signal is generated from the OR circuit 56. Also in this case, as described above, the switch element 57 is switched from on to off.

  In the current interrupt circuit 50, if a voltage value higher than the threshold value V_th is input to the alarm determination circuit 53, it can be determined whether or not the IC 51 operates normally. For example, the voltage values of the plurality of single cells 11 connected in series can be input to the alarm determination circuit 53 by using the plurality of comparators CMP. Since the voltage value of the plurality of unit cells 11 is higher than the voltage value of each unit cell 11, the voltage value of the plurality of unit cells 11 can be made higher than the threshold value V_th.

  When a voltage value higher than the threshold value V_th is input to the alarm determination circuit 53, if the IC 51 is normal, an alarm signal is output from the alarm determination circuit 53, and the switch element 57 is switched from on to off. When switch element 57 is turned off, system main relays SMR-B and SMR-G are turned off. Here, if the capacitor C1 is discharged, the voltage value VL remains lower than the voltage value VB. For example, if the capacitor C1 is discharged to 0 [V] and the voltage value VL remains 0 [V], it can be determined that the current cutoff circuit 50 (IC51) is normal.

  If the system main relays SMR-B and SMR-G are not turned off even though a voltage value higher than the threshold value V_th is input to the alarm determination circuit 53, the current interrupt circuit 50 (IC51) is faulty. Can be determined. When system main relays SMR-B and SMR-G are not turned off, voltage value VL becomes equal to voltage value VB even if capacitor C1 is discharged. For this reason, when the voltage value VL is higher than 0 [V] even though a voltage value higher than the threshold value V_th is input to the alarm determination circuit 53, it can be determined that the current interrupt circuit 50 has failed.

  FIG. 3 shows a configuration of a circuit for driving the system main relays SMR-B and SMR-G. The system main relay SMR-B has a movable contact MC-B and a fixed contact FC-B. The fixed contact FC-B is connected to the positive electrode line PL. When the movable contact MC-B comes into contact with the fixed contact FC-B, the system main relay SMR-B is turned on. When the movable contact MC-B is separated from the fixed contact FC-B, the system main relay SMR-B is turned off.

  The exciting coil 61 is connected to the power source 60. When the current from the power source 60 flows to the exciting coil 61, the magnetic contact generated by energizing the exciting coil 61 brings the movable contact MC-B into contact with the fixed contact FC-B. Can be made. On the other hand, when no current flows through the exciting coil 61, the movable contact MC-B can be separated from the fixed contact FC-B by using the biasing force of a spring (not shown).

  The system main relay SMR-G has a movable contact MC-G and a fixed contact FC-G. The fixed contact FC-G is connected to the negative electrode line NL, and when the movable contact MC-G comes into contact with the fixed contact FC-G, the system main relay SMR-G is turned on. When the movable contact MC-G moves away from the fixed contact FC-G, the system main relay SMR-G is turned off.

  The excitation coil 62 is connected to the power source 60, and the current from the power source 60 can flow through the excitation coil 62. Similar to the system main relay SMR-B, the movable contact MC-G can be brought into contact with the fixed contact FC-G or separated from the fixed contact FC-G by switching between energization and non-energization of the exciting coil 62. it can.

  A switching element (SW, corresponding to the first switching element of the present invention) 63 is provided between the exciting coil 61 and the power source 60. The switch element 63 receives the control signal from the controller 40 and switches between on and off. On the other hand, one end of the switch element 57 of the current interrupt circuit 50 is connected to the exciting coil 62, and the other end of the switch element 57 is grounded. Since the exciting coils 61 and 62 are connected in series, a current flows from the power source 60 to the exciting coils 61 and 62 when the switch elements 63 and 57 are on. If at least one of the switch elements 63 and 57 is OFF, no current flows through the exciting coils 61 and 62.

  A voltage sensor 71 is connected to a line connecting the switch element 63 and the exciting coil 61. When the switch element 63 is on, the voltage value V <b> 1 detected by the voltage sensor 71 is the voltage value of the power supply 60. On the other hand, when the switch element 63 is off, the voltage value V1 is 0 [V].

  In the configuration shown in FIG. 3, since the current flows through the exciting coils 61 and 62 when the switch elements 63 and 57 are on, the system main relays SMR-B and SMR-G can be turned on simultaneously. Here, when the system main relays SMR-B and SMR-G are simultaneously turned on, an inrush current flows from the assembled battery 10 to the capacitor C1. Therefore, the capacitor C1 can be charged before the system main relays SMR-B and SMR-G are turned on. As a power source for charging the capacitor C1, a power source different from that of the assembled battery 10 is used.

  According to the configuration shown in FIG. 3, even if the switch element 63 is in the on state, the current can be prevented from flowing through the exciting coils 61 and 62 by turning off the switch element 57 of the current interrupt circuit 50. . For this reason, it can be prevented that the current continues to flow through the exciting coils 61 and 62 and the system main relays SMR-B and SMR-G remain on.

  In the present embodiment, the positions where the switch elements 63 and 57 are provided are not limited to the positions shown in FIG. That is, as long as the current flows through the exciting coils 61 and 62, the positions where the switch elements 63 and 57 are provided can be set as appropriate. Here, the voltage sensor 71 may be connected to the end opposite to the end of the switch element 63 connected to the power source 60.

  Next, processing for determining a failure of a circuit that drives the system main relays SMR-B and SMR-G will be described with reference to the flowchart shown in FIG. The process shown in FIG. 4 is executed by the controller 40. When the processing shown in FIG. 4 is started, the switch elements 57 and 63 are on.

  In step S <b> 101, the controller 40 outputs a control signal for turning off the switch element 57 of the current interrupt circuit 50. The control signal output from the controller 40 is input to the OR circuit 56 of the current interrupt circuit 50, and the switch element 57 can be turned off by the output signal of the OR circuit 56.

  In step S102, the controller 40 discharges the capacitor C1. For example, the discharge current of the capacitor C1 can be passed through the load 20. As a result, the voltage value of the capacitor C1 decreases, but the voltage decrease amount ΔVc at this time is preset. The controller 40 can discharge the capacitor C1 by the voltage drop amount ΔVc by monitoring the voltage value VL detected by the voltage sensor 32.

  In step S103, the controller 40 determines whether or not a condition represented by the following formula (1) is satisfied.

  The controller 40 can detect the voltage value VB shown in the above equation (1) by using the voltage sensor 31. In addition, the controller 40 can detect the voltage value VL shown in the above equation (1) by using the voltage sensor 32. ΔVc shown in the above equation (1) is a voltage drop amount in the process of step S102.

  When the condition shown in the above equation (1) is not satisfied, the controller 40 determines that the control signal in the process of step S101 is not input to the current interrupt circuit 50. Specifically, the controller 40 determines that an abnormality has occurred in the line connecting the controller 40 and the current interrupt circuit 50 (OR circuit 56). When the control signal from the controller 40 is not input to the current interrupt circuit 50 (OR circuit 56), the switch element 57 of the current interrupt circuit 50 is not turned off. Relays SMR-B and SMR-G remain on.

  As a result, the voltage values VB and VL are equal, and the condition shown in the above equation (1) is not satisfied. At this time, the controller 40 issues a warning in step S106. The warning means may be any means that can warn the user or the like using sound or display.

  When performing the processing of steps S102 and S103, the voltage drop amount ΔVc can be set in consideration of the detection error of the voltage sensors 31 and 32. Depending on the detection errors of the voltage sensors 31 and 32, even if the actual voltage values (true values) VB and VL are equal, the voltage difference between the voltage values (detection values) VB and VL detected by the voltage sensors 31 and 32. ΔVe may occur. In order to exclude this voltage difference ΔVe, the voltage drop amount ΔVc can be set to a value larger than the voltage difference ΔVe.

  When the condition shown in the above equation (1) is satisfied, the controller 40 determines that the control signal in the process of step S101 is input to the current interrupt circuit 50. Specifically, the controller 40 determines that the line connecting the controller 40 and the current interrupt circuit 50 is normal. When the control signal from the controller 40 is input to the current interrupt circuit 50, the switch element 57 is turned off and no current flows through the exciting coils 61 and 62. Therefore, the system main relays SMR-B and SMR-G are turned on. Turn off. As a result, the voltage value VL becomes lower than the voltage value VB by the amount of voltage drop ΔVc, and the condition shown in the above equation (1) is satisfied.

  When the condition shown in the above equation (1) is satisfied, the controller 40 outputs a control signal for turning off the switch element 63 in step S104. Here, if the switch element 63 is normal, the switch element 63 is turned off.

  In step S105, the controller 40 determines whether or not the voltage value V1 detected by the voltage sensor 71 is 0 [V]. When the voltage value V1 is 0 [V], the controller 40 determines that the switch element 63 is normal, and ends the process shown in FIG. On the other hand, if the switch element 63 is in a failure state in the on state, the voltage value V1 indicates the voltage value of the power supply 60 and is higher than 0 [V]. Therefore, when the voltage value V1 is not 0 [V], the controller 40 determines that the switch element 63 has failed. At this time, the controller 40 performs the process of step S106 described above.

  In the process of step S105, the detection error of the voltage sensor 71 can be considered. Specifically, in step S105, it is possible to determine whether or not the voltage value V1 is included in the detection error range of the voltage sensor 71 on the basis of 0 [V]. Here, if the voltage value V1 is included in the detection error range, the controller 40 can determine that the switch element 63 is normal. On the other hand, if the voltage value V1 is not included in the detection error range, the controller 40 can determine that the switch element 63 is in a failure state and is in failure.

  In this embodiment, the failure of the switch element 63 is determined using the voltage sensor 71, but the present invention is not limited to this. Specifically, a failure of the switch element 63 can be determined using a current sensor.

  For example, when the switch element 57 is on, the controller 40 outputs a control signal for turning off the switch element 63. Here, if the switch element 63 is turned off, the current value detected by the current sensor becomes 0 [A]. On the other hand, if the switch element 63 is in the on state and fails, the current value becomes larger than 0 [A]. Thus, based on the current value detected by the current sensor, it can be determined whether or not the switch element 63 is in a failure state in the ON state.

  Next, a battery system that is Embodiment 2 of the present invention will be described. In the present embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Hereinafter, differences from the first embodiment will be mainly described.

  FIG. 5 shows a circuit for driving the system main relays SMR-B and SMR-G in this embodiment. As shown in FIG. 5, the exciting coils 61 and 62 are connected in parallel. One end of the switch element (SW, corresponding to the first switch element of the present invention) 64 is connected to the power source 60, and the other end of the switch element 64 is connected to the exciting coil 61. Thus, by turning on the switch elements 57 and 64, a current can be passed from the power source 60 to the exciting coil 61. On / off of the switch element 64 is controlled by the controller 40.

  A voltage sensor 72 is connected to a line connecting the switch element 64 and the exciting coil 61. When the switch element 64 is on, the voltage value V2 detected by the voltage sensor 72 is higher than 0 [V]. On the other hand, when the switch element 64 is off, the voltage value V2 is 0 [V]. The voltage value V2 detected by the voltage sensor 72 is input to the controller 40.

  The switch element (SW, corresponding to the first switch element of the present invention) 65 and the exciting coil 62 are connected in series to each other and are connected in parallel to the switch element 64 and the exciting coil 61. One end of the switch element 65 is connected to the power source 60, and the other end of the switch element 65 is connected to the exciting coil 62. Thus, by turning on the switch elements 57 and 65, a current can be passed from the power source 60 to the exciting coil 62. On / off of the switch element 65 is controlled by the controller 40.

  A voltage sensor 73 is connected to a line connecting the switch element 65 and the excitation coil 62. When the switch element 65 is on, the voltage value V3 detected by the voltage sensor 73 is higher than 0 [V]. On the other hand, when the switch element 65 is off, the voltage value V3 is 0 [V]. The voltage value V3 detected by the voltage sensor 73 is input to the controller 40.

  According to the configuration shown in FIG. 5, current can be passed through each of the exciting coils 61 and 62 by controlling on and off of the switch elements 64 and 65. Thereby, system main relays SMR-B and SMR-G can be switched on and off at different timings.

  In the configuration shown in FIG. 5, even if at least one of the switch elements 64 and 65 is turned on, the energization to the exciting coils 61 and 62 can be cut off by turning off the switch element 57. it can. Thereby, the same effect as Example 1 can be acquired.

  Next, processing for determining a failure of a circuit that drives the system main relays SMR-B and SMR-G will be described with reference to a flowchart shown in FIG. The process shown in FIG. 6 corresponds to the process shown in FIG. 4 and is executed by the controller 40. In FIG. 6, the same processes as those described in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted. When the processing shown in FIG. 6 is started, the switch elements 57, 64, and 65 are on.

  In the process of step S103, when the condition shown in the above equation (1) is satisfied, the controller 40 outputs a control signal for turning off the switch elements 64 and 65 in step S107. If the switch elements 64 and 65 are normal, the switch elements 64 and 65 are turned off.

  In step S108, the controller 40 determines whether or not the voltage value V2 detected by the voltage sensor 72 is 0 [V]. When the voltage value V2 is 0 [V], the controller 40 determines that the switch element 64 is normal, and performs the process of step S109. If the switch element 64 is on and fails, the voltage value V2 is higher than 0 [V]. For this reason, when the voltage value V2 is not 0 [V], the controller 40 determines that the switch element 64 has failed, and performs the process of step S106.

  In step S109, the controller 40 determines whether or not the voltage value V3 detected by the voltage sensor 73 is 0 [V]. When the voltage value V3 is 0 [V], the controller 40 determines that the switch element 65 is normal, and ends the process shown in FIG. If the switch element 65 is in the on state and fails, the voltage value V3 is higher than 0 [V]. For this reason, when the voltage value V3 is not 0 [V], the controller 40 determines that the switch element 65 has failed, and performs the process of step S106.

  In the processes in steps S108 and S109, the detection errors of the voltage sensors 72 and 73 can be taken into account, as in the case described in the first embodiment (the process in step S105 shown in FIG. 4). Specifically, in step S108 (or step S109), the voltage value V2 (or voltage value V3) is included in the detection error range of the voltage sensor 72 (or voltage sensor 73) on the basis of 0 [V]. It can also be determined whether or not. Here, if the voltage value V2 (or voltage value V3) is included in the detection error range, the controller 40 can determine that the switch element 64 (or switch element 65) is normal. On the other hand, if the voltage value V2 (or voltage value V3) is not included in the detection error range, the controller 40 can determine that the switch element 64 (or switch element 65) has failed.

  In the present embodiment, the failure of the switch elements 64 and 65 is determined using the voltage sensors 72 and 73. However, as described in the first embodiment, the switch elements 64 and 65 are turned on using the current sensor. It is also possible to determine whether or not there is a failure in this state. If the current value detected by the current sensor is greater than 0 [A] despite the output of the control signal for turning off the switch elements 64 and 65, the switch elements 64 and 65 are in the on state and have failed. Can be determined.

  Next, a battery system that is Embodiment 3 of the present invention will be described. In the present embodiment, the same components as those described in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. Hereinafter, differences from the first and second embodiments will be mainly described.

  FIG. 7 shows a circuit for driving the system main relays SMR-B, SMR-G, and SMR-P in this embodiment. In the present embodiment, a system main relay SMR-P is provided in addition to the system main relays SMR-B and SMR-G. System main relay SMR-P is provided in positive electrode line PL, and has movable contact MC-P and fixed contact FC-P. Fixed contact FC-P is connected to positive electrode line PL.

  System main relay SMR-P and resistance element R2 are connected in series to each other and in parallel to system main relay SMR-B. Here, the positive electrode line PL is branched with respect to the system main relays SMR-B and SMR-P. System main relay SMR-P and resistance element R2 can also be connected in parallel to system main relay SMR-G. In this case, system main relay SMR-P and resistance element R2 are provided on negative electrode line NL.

  The resistance element R2 is used to suppress an inrush current from flowing from the assembled battery 10 to the capacitor C1 when the assembled battery 10 and the load 20 are connected. That is, when connecting the assembled battery 10 and the load 20, first, the controller 40 switches the system main relays SMR-P and SMR-G from off to on. Thereby, the discharge current of the assembled battery 10 flows to the resistance element R2, and the inrush current to the capacitor C1 can be suppressed. After charging the capacitor C1 with the discharge current of the assembled battery 10, the controller 40 switches the system main relay SMR-B from off to on. Thereby, the connection of the assembled battery 10 and the load 20 is completed.

  The exciting coils 61, 62, 66 are connected in series, and a current from the power source 60 flows to the exciting coils 61, 62, 66. When a current flows through the exciting coil 66, the magnetic contact generated when the exciting coil 66 is energized brings the movable contact MC-P into contact with the fixed contact FC-P, and the system main relay SMR-P can be turned on. On the other hand, when no current flows through the exciting coil 66, the movable contact MC-P is separated from the fixed contact FC-P by receiving the biasing force of a spring (not shown), and the system main relay SMR-P is turned off. .

  One end of a switch element (SW, corresponding to the first switch element of the present invention) 67 is connected to the power supply 60, and the other end of the switch element 67 is connected to the exciting coil 62. One end of the exciting coil 66 is connected to the switch element 57 of the current interrupt circuit 50. Thus, by turning on the switch elements 67 and 57, a current can be passed through the exciting coils 61, 62, and 66. On / off of the switch element 67 is controlled by the controller 40.

  A voltage sensor 74 is connected to a line connecting the switch element 67 and the exciting coil 62. When the switch element 67 is off, the voltage value V4 detected by the voltage sensor 74 is 0 [V]. On the other hand, when the switch element 67 is on, the voltage value V4 is higher than 0 [V]. The voltage value V4 detected by the voltage sensor 74 is input to the controller 40.

  A switch element (SW, corresponding to the first switch element of the present invention) 68 and a resistance element 69 are connected to the switch element 67 in parallel. The switch element 68 and the resistance element 69 are connected in series. For this reason, even if the switch element 67 is off, if the switch elements 68 and 57 are on, current can flow from the power source 60 to the exciting coils 61, 62 and 66. At this time, the current from the power supply 60 flows through the switch element 68 and the resistance element 69. For this reason, the current value flowing through the exciting coils 61, 62, 66 via the switch element 68 is smaller than the current value flowing through the exciting coils 61, 62, 66 via the switch element 67.

  A voltage sensor 75 is connected to a line connecting the switch element 68 and the exciting coil 62. When the switch element 68 is off, the voltage value V5 detected by the voltage sensor 75 is 0 [V]. On the other hand, when the switch element 68 is on, the voltage value V5 becomes higher than 0 [V]. The voltage value V5 detected by the voltage sensor 75 is input to the controller 40.

  In this embodiment, by switching the value of the current flowing through the exciting coils 61, 62, 66, the timing for switching the system main relay SMR-B from OFF to ON, and the system main relays SMR-G, SMR-P from OFF to ON. The timing to switch to is different. Here, the system main relays SMR-G and SMR-P can be turned on by turning off the switch element 67 and turning on the switch element 68. At this time, the system main relay SMR-B remains off. When the switch element 67 is turned on, the system main relay SMR-B can be turned on.

  For this reason, when connecting the assembled battery 10 and the load 20, the controller 40 turns on the switch element 67 after turning on the switch element 68. Thereby, when connecting the assembled battery 10 and the load 20, the system main relays SMR-B, SMR-G, and SMR-P can be operated as described above. Note that after the switch element 67 is turned on, the switch element 68 is turned off.

  According to the configuration shown in FIG. 7, even if the switch elements 67 and 68 are in the on state, the energization to the exciting coils 61, 62 and 66 is performed by turning off the switch element 57 of the current interrupt circuit 50. Can be cut off. Thereby, the same effect as Example 1 can be acquired.

  Next, processing for determining a failure of a circuit driving system main relays SMR-B, SMR-G, and SMR-P will be described with reference to the flowchart shown in FIG. The process shown in FIG. 8 corresponds to the process shown in FIG. 4 and is executed by the controller 40. 8, the same processes as those described in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted. When the processing shown in FIG. 8 is started, the switch elements 57 and 68 are on. The controller 40 outputs a control signal for turning off the switch element 67.

  After performing the process of step S101, the controller 40 discharges the capacitor C1 to 0 [V] in step S110. In step S111, the controller 40 determines whether or not the voltage value VL detected by the voltage sensor 32 is 0 [V].

  When the voltage value VL is not 0 [V], the controller 40 determines that the control signal in the process of step S101 is not input to the current interrupt circuit 50. Specifically, the controller 40 determines that an abnormality has occurred in the line connecting the controller 40 and the current interrupt circuit 50. When the control signal from the controller 40 is not input to the current interrupt circuit 50, the system main relays SMR-B, SMR-G, and SMR-P are not turned off, and the voltage value VL becomes equal to the voltage value VB. Therefore, the voltage value VL does not become 0 [V], and the controller 40 can determine that the control signal is not input to the current interrupt circuit 50. At this time, the controller 40 performs the process of step S106.

  When the voltage value VL is 0 [V], the controller 40 determines that the control signal in the process of step S101 is input to the current interrupt circuit 50. Specifically, the controller 40 determines that the line connecting the controller 40 and the current interrupt circuit 50 is normal. In step S112, the controller 40 outputs a control signal for turning off the switch element 68. Here, if the switch element 68 is normal, the switch element 68 is turned off.

  In step S113, the controller 40 determines whether or not the voltage value V4 detected by the voltage sensor 74 is 0 [V]. When the voltage value V4 is not 0 [V], the controller 40 determines that the switch element 67 is on and has a failure, and performs the process of step S106. As described above, if the switch element 67 is on, the voltage value V4 becomes higher than 0 [V]. Therefore, the controller 40 confirms that the voltage value V4 is not 0 [V]. It can be determined that the element 67 is in a failure state in the on state. On the other hand, when the voltage value V4 is 0 [V], the controller 40 determines that the switch element 67 is normal, and proceeds to the process of step S114.

  In step S114, the controller 40 determines whether or not the voltage value V5 detected by the voltage sensor 75 is 0 [V]. When the voltage value V5 is not 0 [V], the controller 40 determines that the switch element 68 is on and has a failure, and performs the process of step S106. As described above, if the switch element 68 is on, the voltage value V5 becomes higher than 0 [V]. Therefore, the controller 40 confirms that the voltage value V5 is not 0 [V]. It can be determined that the element 68 is in the on state and has failed. On the other hand, when the voltage value V5 is 0 [V], the controller 40 determines that the switch element 68 is normal, and ends the process shown in FIG.

  In the processes of steps S111, S113, and S114, the detection errors of the voltage sensors 32, 74, and 75 can be taken into consideration, as in the first embodiment (the process of step S105 shown in FIG. 4). That is, it is possible to determine whether or not the voltage value VL (V4, V5) is included in the detection error range of the voltage sensor 32 (74, 75) with reference to 0 [V]. Further, instead of the processes of steps S110 and S111, the processes of steps S102 and S103 shown in FIG. 4 can be performed.

  In this embodiment, the failure of the switch elements 67 and 68 is determined using the voltage sensors 74 and 75. However, as described in the first embodiment, the switch elements 67 and 68 are turned on using the current sensor. It is also possible to determine whether or not there is a failure in this state. If the current value detected by the current sensor is larger than 0 [A] despite the output of the control signal for turning off the switch elements 67 and 68, the switch elements 67 and 68 are in the on state and have failed. Can be determined.

10: assembled battery, 11: single cell, 20: load, 31, 32: voltage sensor,
40: Controller, 50: Current interrupt circuit, 57: Switch element, 60: Power supply,
61, 62, 66: exciting coil, 63, 64, 65, 67, 68: switch element,
71, 72, 73, 74, 75: voltage sensor

Claims (1)

A power storage device including a plurality of power storage elements electrically connected in series;
A relay that connects the power storage device to a load when the excitation coil is energized, and that disconnects the connection between the power storage device and the load when the excitation coil is not energized;
A first switch element that switches between ON to allow energization of the excitation coil and OFF to block energization of the excitation coil;
A current interruption circuit including a second switch element that interrupts energization of the exciting coil when the voltage value of the electricity storage element detected using a voltage detection line is higher than a threshold;
A controller for controlling each of the first switch element and the second switch element;
A power storage system comprising: