JP2015061503A - Power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage system which can discriminate fastening of a relay by using a detection result of a voltage sensor.SOLUTION: When a first diode and a second diode are installed, a charge current flows in a first capacitor and a second capacitor by the first diode or the second diode when a relay on a positive pole line or a negative pole line and a relay on an intermediate line are ON. Thus, voltage values of the first capacitor and the second capacitor rise, and the voltage values detected by a voltage sensor become higher than a reference voltage value. When the relay on the positive pole line or the negative pole line, or the relay on the intermediate line is controlled to be OFF, the voltage value detected by the voltage sensor becomes higher than the reference voltage value as mentioned if the relay which is controlled to be OFF is fixed. Thus, the relay which is controlled to be OFF can be discriminated to be fixed by checking that the voltage value detected by the voltage sensor is higher than the reference voltage value.

Description

  The present invention relates to a power storage system that uses a detection result of a voltage sensor to determine whether a relay is stuck.

  The relay has a movable contact and a fixed contact, and the movable contact may be fixed to the fixed contact. Therefore, it is necessary to determine whether or not the relay is fixed. Here, after performing the control to turn off the relay, it can be determined that the relay is fixed when the current path including the relay is in the energized state. In determining whether or not the current path including the relay is in the energized state, the detection result of the voltage sensor can be used.

  On the other hand, in the battery system described in Patent Document 1, the assembled battery 110 is connected to the load via the positive electrode line 101 and the negative electrode line 102 as shown in FIG. Then, two capacitors 121 and 122 are connected in series. The assembled battery 110 includes two battery groups 111 and 112 connected in series. The connection point between the two battery groups 111 and 112 and the connection point between the two capacitors 121 and 122 are intermediate. Line 103 is connected. Relays 131, 132, and 133 are provided on the lines 101, 102, and 103, respectively.

  As shown in FIG. 22, if the voltage value between the positive electrode line 101 and the negative electrode line 102 is detected by the voltage sensor 140, it is possible to determine whether the relays 131 and 132 are stuck. For example, control for turning off the relay 131 and control for turning on the relay 132 are performed. Here, if the voltage value detected by the voltage sensor 140 indicates the voltage value of the assembled battery 110, it can be determined that the relay 131 is fixed.

International Publication No. 2013/061358 Pamphlet JP 2012-202723 A

  In the battery system shown in FIG. 22, it is possible to determine whether the relays 131 and 132 are fixed using the detection result of the voltage sensor 140, but it is not possible to determine whether the relay 133 is fixed. For example, as shown in FIG. 23, when the relays 131 and 133 are on and the relay 132 is normal and off, the capacitor 121 remains in the battery group 111 even if the load is operated and the capacitors 121 and 122 are discharged. It is charged by the discharge current. That is, the electric charge remains in the capacitor 121.

  At this time, as shown in FIG. 23, electric charges (+ Q, −Q) are accumulated in both poles of the capacitor 121. As a result, charges (−Q, + Q) shown in FIG. 23 are accumulated in both electrodes of the discharged capacitor 122.

  As a result, the voltage value detected by the voltage sensor 140 indicates 0 [V]. Here, since the voltage value detected by the voltage sensor 140 indicates 0 [V] even when the relay 132 is normal and off and the relays 131 and 133 are off, the relays 131 and 133 are on. And the off state cannot be distinguished. Therefore, it cannot be determined whether or not at least one of the relays 131 and 133 is fixed.

  In addition, if the voltage value between the positive electrode line 101 and the intermediate line 103 is detected, or the voltage value between the negative electrode line 102 and the intermediate line 103 is detected, it is determined whether or not the relay 133 is fixed. it can. However, in this case, in order to detect the respective voltage values (that is, the voltage values of the capacitors 121 and 122), a voltage sensor must be added, and the cost increases by the added voltage sensor. Resulting in.

  The power storage system of the present invention includes a power storage device, a capacitor, a relay, a diode, a voltage sensor, and a controller. The power storage device is connected to a load via a positive electrode line and a negative electrode line, and includes a first power storage group and a second power storage group connected in series. Each of the first power storage group and the second power storage group includes a plurality of power storage elements connected in series, and each power storage element includes a current breaker that interrupts a current path of the power storage elements.

  An intermediate line is connected to the connection point of the first power storage group and the second power storage group. The capacitor includes a first capacitor connected to the positive electrode line and the intermediate line, and a second capacitor connected to the negative electrode line and the intermediate line. The relay is provided in each of the positive electrode line, the negative electrode line, and the intermediate line.

  The diode has a first diode and a second diode. The cathode of the first diode is connected to the positive line between the relay and the first capacitor on the positive line, and the anode of the first diode is connected to the intermediate line between the relay and the first capacitor on the intermediate line. Yes. The cathode of the second diode is connected to the intermediate line between the relay and the second capacitor on the intermediate line, and the anode of the second diode is connected to the negative line between the relay and the second capacitor on the negative line. Yes.

  A voltage sensor detects the voltage value between a positive electrode line and a negative electrode line, and a controller controls on and off of each relay. Here, when the relay on the positive line or the negative line and the relay on the intermediate line are on, the controller performs control to turn off one of these relays. Here, when the voltage value detected by the voltage sensor is higher than the reference voltage value (approximately 0 [V]) when the first capacitor and the second capacitor are not charged, the relay controlled to be off is fixed. Is determined.

  In the electricity storage system of the present invention, when the first diode and the second diode are omitted, as described with reference to FIG. 23, when the relay on the positive line or the negative line and the relay on the intermediate line are on. The voltage value detected by the voltage sensor is below the reference voltage value. In this case, even if the relay controlled to be off is fixed, it is impossible to determine whether the relay is fixed using the detection result of the voltage sensor.

  In the present invention, when the relay on the positive line and the relay on the intermediate line are on, the first capacitor is charged by the discharge current of the power storage device (first power storage group or second power storage group), and the first capacitor The voltage value of the capacitor is higher than the reference voltage value. For example, when the first power storage group is connected to the positive electrode line and the intermediate line, the voltage value of the first capacitor indicates the voltage value of the first power storage group and is higher than the reference voltage value. Here, the voltage sensor can detect the voltage value of the first capacitor in the current path including the first capacitor and the second diode.

  On the other hand, when the relay on the negative electrode line and the relay on the intermediate line are on, the second capacitor is charged by the discharge current of the power storage device (first power storage group or second power storage group), and the second capacitor The voltage value is higher than the reference voltage value. For example, when the second power storage group is connected to the negative electrode line and the intermediate line, the voltage value of the second capacitor indicates the voltage value of the second power storage group and is higher than the reference voltage value. Here, the voltage sensor can detect the voltage value of the second capacitor in the current path including the second capacitor and the first diode.

  Here, when one of the relay on the positive line or the negative line and the relay on the intermediate line is controlled to be off, if the relay to be turned off is fixed, it is detected by the voltage sensor as described above. Voltage value becomes higher than the reference voltage value. Therefore, by confirming that the voltage value detected by the voltage sensor is higher than the reference voltage value, the relay controlled to be off (the relay on the positive line or the negative line or the relay on the intermediate line) is fixed. Can be determined.

  According to the present invention, as described above, it is possible to determine whether or not the relay is stuck only by using a voltage sensor that detects a voltage value between the positive electrode line and the negative electrode line. Thereby, it is not necessary to detect the voltage value between the positive electrode line and the intermediate line and the voltage value between the negative electrode line and the intermediate line, and it is not necessary to newly add a voltage sensor. Therefore, an increase in cost due to the addition of the voltage sensor can be suppressed. In the present invention, the first diode and the second diode are provided, but the cost can be reduced as compared with a case where a voltage sensor is newly added.

  When the relay on the intermediate line and the relay on the positive line are on and the relay on the negative line is off, the relay on the intermediate line is fixed by performing control to turn off the relay on the intermediate line. Can be determined. Here, when the relay on the intermediate line is fixed, the first capacitor is charged by the discharge current of the first power storage group. The voltage value of the first capacitor becomes equal to the voltage value of the first power storage group, and the voltage sensor detects the voltage value of the first capacitor.

  Thereby, the relay on the intermediate line is fixed by confirming that the voltage value (voltage value of the first capacitor) detected by the voltage sensor is equal to the voltage value of the first power storage group higher than the reference voltage value. Can be determined. Here, the voltage value of the first power storage group can be detected using a voltage sensor provided in advance in order to control charging / discharging of the power storage device.

  On the other hand, when the relay on the positive line is off and the relay on the intermediate line and the relay on the negative line are on, the relay on the intermediate line is controlled by turning off the relay on the intermediate line. Can be discriminated. Here, when the relay on the intermediate line is fixed, the second capacitor is charged by the discharge current of the second power storage group. Then, the second capacitor becomes equal to the voltage value of the second power storage group, and the voltage sensor detects the voltage value of the second capacitor.

  Accordingly, the relay on the intermediate line is fixed by confirming that the voltage value detected by the voltage sensor (the voltage value of the second capacitor) is equal to the voltage value of the second power storage group that is higher than the reference voltage value. Can be determined. Here, the voltage value of the second power storage group can be detected using a voltage sensor provided in advance in order to control charging / discharging of the power storage device.

  Relays on the intermediate line can include two relays connected in parallel. Here, a resistance element can be connected in series to one of the relays. By using the resistance element, it is possible to prevent an inrush current from flowing through the first capacitor and the second capacitor when the power storage device and the load are connected. Specifically, when connecting the power storage device and the load, first, by turning on a relay connected in series with the resistance element, the discharge current of the power storage device (the first power storage group or the second power storage group) It can flow to the first capacitor or the second capacitor via the resistance element.

  Here, each of the relays on the positive line and the negative line can include two relays connected in parallel like the relay on the intermediate line described above, and one of the relays includes a resistance element. Can be connected in series. By using these resistance elements, it is possible to prevent an inrush current from flowing through the first capacitor and the second capacitor when the power storage device and the load are connected.

  The intermediate line may include a first intermediate line to which the first capacitor and the first diode are connected, and a second intermediate line to which the second capacitor and the second diode are connected. Here, a capacitor and a diode can be connected to the first intermediate line and the second intermediate line. The cathode of the diode can be connected to the first intermediate line and the anode can be connected to the second intermediate line.

  Even in the power storage system including the first intermediate line and the second intermediate line, as in the case described above, the relay is fixed on the first intermediate line or the second intermediate line based on the detection result of the voltage sensor. Or the adhering of the relay on the positive electrode line or the negative electrode line can be determined.

It is a figure which shows the structure of the battery system which is Example 1. FIG. It is a figure which shows the structure of a cell. In Example 1, it is a flowchart which shows the process at the time of starting of a battery system. In Example 1, it is a flowchart which shows the process at the time of starting of a battery system (modification). It is a figure explaining the current pathway which detects the voltage value of the 2nd capacitor. It is a figure explaining the current path which detects the voltage value of the 1st capacitor. In Example 1, it is a flowchart which shows the process at the time of a stop of a battery system. In Example 1, it is a flowchart which shows the process at the time of a battery system stop (modification). It is a figure which shows the structure of the battery system which is Example 2. FIG. In Example 2, it is a flowchart which shows the process at the time of starting of a battery system. In Example 2, it is a flowchart which shows the process at the time of starting of a battery system (modification). In Example 2, it is a flowchart which shows the process at the time of a stop of a battery system. FIG. 4 is a diagram showing a partial configuration of a battery system that is Example 3. It is a figure which shows the structure of the battery system which is the reference example 1. FIG. 10 is a flowchart illustrating a process of determining whether the system main relay is stuck in Reference Example 1. It is a figure which shows the structure of the battery system which is the reference example 2. FIG. 10 is a flowchart illustrating a process of determining whether the system main relay is stuck in Reference Example 2. In the reference example 2, it is a figure which shows a state when only a 2nd capacitor | condenser is charged. In the reference example 3, it is a figure which shows the structure of a battery system. 10 is a flowchart illustrating a process of determining whether the system main relay is stuck in Reference Example 3. In the reference example 3, it is a figure which shows a state when only a 1st capacitor | condenser is charged. It is a figure which shows a part of structure in the conventional battery system. It is a figure explaining the voltage value when two relays are adhering.

  Examples of the present invention will be described below.

  A battery system (corresponding to the power storage system of the present invention) that is Embodiment 1 of the present invention will be described. FIG. 1 is a schematic diagram showing a configuration of a battery system. The battery system of the present embodiment can be mounted on a vehicle.

  The assembled battery 10 includes a first battery group (corresponding to a first power storage group of the present invention) 10A and a second battery group (corresponding to a second power storage group of the present invention) 10B connected in series. Each of the battery groups 10A and 10B includes a plurality of single cells (corresponding to the storage element of the present invention) 11 connected in series. As the cell 11, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. An electric double layer capacitor can be used instead of the secondary battery.

  At least one of the battery groups 10A and 10B may include a plurality of single cells 11 connected in parallel. The number of single cells 11 constituting each battery group 10A, 10B can be set as appropriate. For example, the number of single cells 11 constituting the first battery group 10A (the number of single cells 11 connected in series) and the number of single cells 11 constituting the second battery group 10B (single cells connected in series). 11 number) can be made equal.

  A system main relay SMR-B is provided in a positive electrode line (also referred to as an electrode line) PL connected to a positive electrode terminal of the assembled battery 10 (in other words, a positive electrode terminal of the first battery group 10A). System main relay SMR-B receives a control signal from controller 40 and switches between on and off. A system main relay SMR-G is provided in a negative electrode line (also referred to as an electrode line) NL connected to a negative electrode terminal of the assembled battery 10 (in other words, a negative electrode terminal of the second battery group 10B). System main relay SMR-G is switched between on and off in response to a control signal from controller 40.

  An intermediate line ML is connected to a connection point P1 between the first battery group 10A and the second battery group 10B, and a system main relay SMR-C is provided in the intermediate line ML. System main relay SMR-C receives a control signal from controller 40 and switches between on and off.

  A resistance element R and a system main relay SMR-P are connected in parallel to the system main relay SMR-C, and the resistance element R and the system main relay SMR-P are connected in series. System main relay SMR-P is switched between on and off in response to a control signal from controller 40. The resistance element R is used to suppress an inrush current from flowing from the assembled battery 10 (respective battery groups 10A and 10B) to the capacitors C1 and C2.

  A first capacitor C1 is connected to the positive electrode line PL and the intermediate line ML, and a second capacitor C2 is connected to the negative electrode line NL and the intermediate line ML. In other words, the intermediate line ML is connected to the connection point P2 of the first capacitor C1 and the second capacitor C2. The capacitors C1 and C2 are connected in series between the positive electrode line PL and the negative electrode line NL. Capacitors C1 and C2 are used to smooth the voltage value between positive line PL and negative line NL.

  The cathode of the first diode D1 is connected to the positive line PL, and the anode of the first diode D1 is connected to the intermediate line ML. Here, the connection point P3 of the positive electrode line PL and the first diode D1 is located between the connection point P4 of the positive electrode line PL and the first capacitor C1 and the system main relay SMR-B. The connection point P5 between the intermediate line ML and the first diode D1 is located between the connection point P2 between the intermediate line ML and the first capacitor C1 and the system main relays SMR-C and SMR-P.

  The cathode of the second diode D2 is connected to the intermediate line ML, and the anode of the second diode D2 is connected to the negative line NL. Here, the diodes D1 and D2 are connected in series between the positive electrode line PL and the negative electrode line NL. The connection point P5 between the intermediate line ML and the second diode D2 is located between the connection point P2 between the intermediate line ML and the second capacitor C2 and the system main relays SMR-C and SMR-P. The connection point P6 between the negative electrode line NL and the second diode D2 is located between the connection point P7 between the negative electrode line NL and the second capacitor C2 and the system main relay SMR-G.

  The voltage sensor 21 detects the voltage value VB1 of the first battery group 10A and outputs the detection result to the controller 40. The voltage sensor 22 detects the voltage value VB2 of the second battery group 10B and outputs the detection result to the controller 40. The detection results of the voltage sensors 21 and 22 are used when controlling charging / discharging of the assembled battery 10. In addition, since the sum of the voltage values VB1 and VB2 becomes the voltage value VBt of the assembled battery 10, the voltage value VBt can be calculated by detecting the voltage values VB1 and VB2.

  The voltage sensor (corresponding to the voltage sensor of the present invention) 23 detects the voltage value VL between the positive electrode line PL and the negative electrode line NL, and outputs the detection result to the controller 40. Here, one end of the voltage sensor 23 is connected to the positive line PL between the connection point P4 and the inverter 31, and the other end of the voltage sensor 23 is connected to the negative line NL between the connection point P7 and the inverter 31. Yes.

  The assembled battery 10 is connected to the inverter 31 via the positive electrode line PL and the negative electrode line NL. The inverter 31 converts the DC power output from the assembled battery 10 into AC power, and outputs the AC power to the motor generator (corresponding to the load of the present invention) 32. The inverter 31 converts AC power output from the motor / generator 32 into DC power, and outputs the DC power to the assembled battery 10.

  The motor / generator 32 receives the AC power output from the inverter 31 and generates kinetic energy for running the vehicle. Further, the motor / generator 32 converts kinetic energy generated during braking of the vehicle into AC power, and outputs the AC power to the inverter 31.

  A boost circuit can be provided in the current path between the assembled battery 10 and the inverter 31. Specifically, the booster circuit can be connected to the electrode lines PL and NL located between the voltage sensor 23 and the inverter 31. The booster circuit can boost the output voltage of the assembled battery 10 and output the boosted power to the inverter 31. The booster circuit can step down the output voltage of the inverter 31 and output the stepped down power to the assembled battery 10. The controller 40 controls the operation of the inverter 31 and the booster circuit. When controlling the operation of the inverter 31 and the booster circuit, the detection result of the voltage sensor 23 can be used.

  The controller 40 has a memory 41, and the memory 41 stores predetermined information. Here, the memory 41 can be built in the controller 40 as shown in FIG. 1 or can be provided outside the controller 40. Information about on / off of the ignition switch of the vehicle is input to the controller 40.

  FIG. 2 shows the configuration of the unit cell 11. The unit cell 11 includes a power generation element 11 a that charges and discharges, and a current breaker 11 b that blocks a current path of the unit cell 11. The power generation element 11a can be composed of, for example, a positive electrode element, a negative electrode element, and a separator disposed between the positive electrode element and the negative electrode element. The positive electrode element has a current collector plate and a positive electrode active material layer, and the negative electrode element has a current collector plate and a negative electrode active material layer. An electrolyte solution is infiltrated into the separator, the positive electrode active material layer, and the negative electrode active material layer. Instead of using a separator containing an electrolytic solution, a solid electrolyte can also be used.

  The current breaker 11b is built in the unit cell 11, and interrupts the current flowing through the unit cell 11 when the unit cell 11 is in an abnormal state such as an overcharged state. As the current breaker 11b, for example, a valve that deforms according to the internal pressure of the unit cell 11 can be used. Gas may be generated inside the cell 11 due to overcharging of the cell 11 or the like. Since the internal pressure of the unit cell 11 increases due to the generation of gas, the valve can be deformed as the internal pressure increases. By deforming the valve and electrically and mechanically disconnecting the power generation element 11a, the current path of the unit cell 11 can be interrupted.

  The current breaker 11b is not limited to the configuration including the valve described above. In other words, the current breaker 11b only needs to be able to interrupt the current path inside the unit cell 11 in order to avoid an abnormal state of the unit cell 11. As the current breaker 11b, in addition to the above-described valve, for example, a fuse or the like can be used. If a fuse is used, when a current of a predetermined value or more flows through the unit cell 11 (fuse), the fuse can be blown to cut off the current path of the unit cell 11.

  When the assembled battery 10 is being charged / discharged, when the current breaker 11b is activated in any of the unit cells 11, a voltage is applied between the terminals of the current breaker 11b in the activated state. According to the present embodiment, by providing the intermediate line ML, the voltage applied between the terminals of the current breaker 11b can be reduced as compared with the configuration in which the intermediate line ML is omitted.

  When the assembled battery 10 is being discharged, for example, in the first battery group 10A, when the current breaker 11b of the unit cell 11 connected to the positive line PL is activated, the current breaker 11b has a terminal between the terminals. A reverse voltage corresponding to the voltage value VB1 of one battery group 10A is applied. Here, if the intermediate line ML is omitted, a reverse voltage corresponding to the voltage value VBt of the assembled battery 10 is applied between the terminals of the current breaker 11b.

  Since the voltage value VB1 of the first battery group 10A is lower than the voltage value VBt of the assembled battery 10, according to the present embodiment, the voltage applied between the terminals of the current breaker 11b can be reduced. In addition, even if it is a case where the current circuit breaker 11b of the other cell 11 act | operates, according to a present Example, the voltage value applied between the terminals of the current circuit breaker 11b can be reduced.

  When the assembled battery 10 is being charged, for example, in the first battery group 10A, when the current breaker 11b of the unit cell 11 connected to the positive electrode line PL is activated, electric charge is accumulated in the first capacitor C1, and the first The voltage value of the capacitor C1 increases. A voltage corresponding to the difference between the voltage value VB1 of the first battery group 10A and the voltage value of the capacitor C1 is applied between the terminals of the current breaker 11b in the operating state.

  Here, if the intermediate line ML is omitted, a voltage corresponding to the difference between the total voltage value of the capacitors C1 and C2 and the voltage value VBt of the assembled battery 10 is present between the terminals of the current breaker 11b in the activated state. It will be applied. Since the voltage values of the capacitors C1 and C2 are increased, the voltage applied to the current breaker 11b in the configuration in which the intermediate line ML is omitted is the voltage applied to the current breaker 11b in the configuration in which the intermediate line ML is provided. Higher than. Therefore, according to the present embodiment, the voltage applied between the terminals of the current breaker 11b can be reduced. In addition, even if it is a case where the current circuit breaker 11b of the other cell 11 act | operates, according to a present Example, the voltage value applied between the terminals of the current circuit breaker 11b can be reduced.

  Further, according to this embodiment, when one of the battery groups 10A and 10B fails, the vehicle can be driven using the output of the battery group that does not fail. For example, when the first battery group 10A fails, the connection between the first battery group 10A and the inverter 31 can be disconnected by turning off the system main relay SMR-B. Here, since the second battery group 10B is connected to the inverter 31 via the system main relays SMR-C and SMR-G, the vehicle can be driven using the output power of the second battery group 10B. .

  Next, in the battery system of this embodiment, a process for determining whether the system main relays SMR-B, SMR-G, SMR-P, and SMR-C are fixed will be described. Here, the sticking can be determined when the battery system is started and when the battery system is stopped.

  FIG. 3 is a flowchart showing processing when starting the battery system. When the ignition switch is switched from OFF to ON, the processing shown in FIG. 3 is started. Here, the process shown in FIG. 3 is executed by the controller 40. When the processing shown in FIG. 3 is started, the system main relays SMR-B, SMR-G, SMR-P, and SMR-C are turned off.

  In step S101, the controller 40 outputs a control signal for turning on the system main relay SMR-P. In response to this control signal, system main relay SMR-P is switched from off to on. In step S102, the controller 40 outputs a control signal for turning on the system main relay SMR-G. In response to this control signal, the system main relay SMR-G is switched from off to on. Here, the processes of steps S101 and S102 may be performed simultaneously, or after the process of step S102, the process of step S101 may be performed.

  In step S103, the controller 40 determines whether or not the voltage value VL is equal to or higher than the voltage value VBt based on the detection results of the voltage sensors 21 to 23. When the voltage value VL is lower than the voltage value VBt, the controller 40 performs the process of step S105. On the other hand, when voltage value VL is equal to or higher than voltage value VBt, controller 40 determines in step S104 that system main relay SMR-B is fixed.

  When system main relay SMR-B is fixed, capacitors C1 and C2 are charged by the discharge current of battery pack 10. Thereby, the voltage value VL detected by the voltage sensor 23 becomes equal to the voltage value VBt of the assembled battery 10. Therefore, when the voltage value VL is equal to or higher than the voltage value VBt, it can be determined that the system main relay SMR-B is fixed.

  When voltage value VL is lower than voltage value VBt, controller 40 determines that system main relay SMR-B is not locked, and in step S105, a control signal for turning on system main relay SMR-B. Is output. In response to this control signal, system main relay SMR-B is switched from off to on. In step S106, the controller 40 outputs a control signal for turning on the system main relay SMR-C, and outputs a control signal for turning off the system main relay SMR-P. Here, the system main relay SMR-C receives a control signal from the controller 40 and switches from off to on. Further, the system main relay SMR-P is switched from on to off in response to a control signal from the controller 40 if not fixed.

  When the process of step S106 is finished, the connection between the assembled battery 10 and the inverter 31 is finished, and the battery system is activated (Ready-ON). When the battery system is in the activated state, system main relays SMR-B, SMR-G, and SMR-C are on.

  In the process of step S104, when it is determined that the system main relay SMR-B is fixed, the controller 40 can warn the user or the like. As a warning means, a known means can be appropriately employed. For example, a sound indicating a warning can be output, or information indicating a warning can be displayed on a display. Accordingly, a dealer such as a dealer can check the system main relays SMR-B, SMR-G, SMR-P, and SMR-C. Further, when it is determined that the system main relay SMR-B is fixed, the battery system may not be started.

  On the other hand, the process shown in FIG. 4 can be performed instead of the process shown in FIG. 4, the same processes as those described in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted. Hereinafter, differences from the processing illustrated in FIG. 3 will be mainly described.

  The controller 40 performs the process of step S107 after performing the process of step S102. In step S107, the controller 40 determines whether or not the voltage values VL and VB2 are equal.

  When system main relays SMR-P and SMR-G are on and system main relay SMR-B is not fixed, second capacitor C2 is charged by the discharge current of second battery group 10B. As a result, the voltage value of the second capacitor C2 becomes equal to the voltage value VB2 of the second battery group 10B. Here, the voltage sensor 23 can detect the voltage value of the second capacitor C2 using a current path (a current path including the second capacitor C2 and the first diode D1) indicated by a dotted line in FIG.

  Thereby, since the voltage values VL and VB2 are equal, it can be determined that the system main relay SMR-B is not fixed by confirming that the voltage values VL and VB2 are equal. When the voltage values VL and VB2 are equal, the controller 40 performs the process of step S105. On the other hand, if the voltage values VL and VB2 are different, the controller 40 can determine in step S104 that the system main relay SMR-B is fixed. When system main relay SMR-B is fixed, voltage value VL is equal to or higher than voltage value VBt, and voltage values VL and VB2 are different.

  In the process of step S107, it is also possible to determine whether or not the condition of the following equation (1) is satisfied in consideration of variations in the voltage values VL and VB2. Variations in the voltage values VL and VB2 may occur due to variations in detection errors of the voltage sensors 22 and 23. Further, the voltage values VL and VB2 may vary due to the detection timings of the voltage sensors 22 and 23 being shifted. In consideration of such variations, it is possible to determine whether or not the voltage values VL and VB2 are equal.

  The constant α1 shown in the above equation (1) is a value that allows variations in the voltage values VL and VB2 (a value greater than 0), and can be set as appropriate in consideration of the variations in the voltage values VL and VB2. it can. However, the value of “VB2 + α1” is a value lower than the voltage value VBt. When the condition shown in the above equation (1) is satisfied, it can be determined that the voltage values VL and VB2 are equal. Further, when the condition shown in the above equation (1) is not satisfied, it can be determined that the voltage values VL and VB2 are different.

  In the process of step S102 shown in FIG. 3 or FIG. 4, instead of outputting a control signal for turning on system main relay SMR-G, a control signal for turning on system main relay SMR-B is sent. Can be output. In this case, it can be determined in step S104 that the system main relay SMR-G is fixed. In the process of step S105, instead of outputting a control signal for turning on the system main relay SMR-B, a control signal for turning on the system main relay SMR-G can be outputted.

  Here, in the process of step S107 shown in FIG. 4, instead of determining whether or not the voltage values VL and VB2 are equal, it is determined whether or not the voltage values VL and VB1 are equal. When system main relays SMR-P and SMR-B are turned on, first capacitor C1 is charged by the discharge current of first battery group 10A. As a result, the voltage value of the first capacitor C1 becomes equal to the voltage value VB1 of the first battery group 10A. Here, the voltage sensor 23 can detect the voltage value of the first capacitor C1 using a current path (a current path including the first capacitor C1 and the second diode D2) indicated by a dotted line in FIG.

  Thereby, since the voltage values VL and VB1 become equal, it can be determined that the system main relay SMR-G is not fixed by confirming that the voltage values VL and VB1 are equal. On the other hand, if system main relay SMR-G is fixed, voltage value VL is equal to or higher than voltage value VBt, and voltage values VL and VB1 are different. Therefore, if the voltage values VL and VB1 are different, it can be determined that the system main relay SMR-G is fixed.

  Next, processing when the battery system is stopped will be described with reference to the flowchart shown in FIG. The process shown in FIG. 7 is started when the ignition switch is switched from on to off, and is executed by the controller 40. When the processing shown in FIG. 7 is started, the system main relays SMR-B, SMR-C, and SMR-G are turned on.

  In step S201, the controller 40 outputs a control signal for turning off the system main relay SMR-C. If the system main relay SMR-C is not fixed, it receives a control signal from the controller 40 and switches from on to off. In step S202, the controller 40 outputs a control signal for turning off the system main relay SMR-G. If the system main relay SMR-G is not fixed, it receives a control signal from the controller 40 and switches from on to off. Note that the processes in steps S201 and S202 may be performed simultaneously, or after the process in step S202 is performed, the process in step S201 may be performed.

  In step S203, the controller 40 discharges the capacitors C1 and C2. In the process of step S203, it is sufficient that the capacitors C1 and C2 can be discharged, and this discharging method can be selected as appropriate. For example, the capacitors C1 and C2 can be discharged by turning on all the switching elements included in the inverter 31. In the battery system including the booster circuit, the capacitors C1 and C2 can be discharged by turning on the two switching elements included in the booster circuit.

  In step S204, the controller 40 determines whether or not the voltage values VL and VBt are equal. Here, it is also possible to determine whether or not the condition shown in the following formula (2) is satisfied in consideration of variations in the voltage values VL and VBt.

  The constant α2 shown in the above equation (2) is a value that allows variations in the voltage values VL and VBt (a value greater than 0), and can be set as appropriate in consideration of variations in the voltage values VL and VBt. When the condition shown in the above equation (2) is satisfied, it can be determined that the voltage values VL and VBt are equal. Further, when the condition shown in the above formula (2) is not satisfied, it can be determined that the voltage values VL and VBt are different.

  When voltage values VL and VBt are equal, controller 40 determines in step S205 that system main relay SMR-G is fixed. Although the system main relays SMR-C and SMR-G are controlled to be turned off by the processing of steps S201 and S202, the system main relay SMR-G is turned on when the voltage values VL and VBt are equal. I understand that. Therefore, in the process of step S205, it is determined that the system main relay SMR-G is fixed.

  On the other hand, when the voltage values VL and VBt are different, the controller 40 can determine that the system main relay SMR-G is not fixed. When system main relay SMR-G is not fixed, voltage value VL indicates approximately 0 [V], or voltage value VL is equal to voltage value VB1 as described later. That is, since the voltage values VL and VBt are different, it can be determined that the system main relay SMR-G is not fixed. Note that substantially 0 [V] means that a detection error of the voltage sensor 23 is included.

  In step S206, it is determined whether or not the voltage values VL and VB1 are equal. Here, it is also possible to determine whether or not the condition shown in the following formula (3) is satisfied in consideration of variations in the voltage values VL and VB1.

  The constant α3 shown in the above equation (3) is a value that allows variations in the voltage values VL and VB1 (a value greater than 0), and can be set as appropriate in consideration of variations in the voltage values VL and VB1. When the condition shown in the above equation (3) is satisfied, it can be determined that the voltage values VL and VB1 are equal. Further, when the condition shown in the above equation (3) is not satisfied, it can be determined that the voltage values VL and VB1 are different.

  When the voltage values VL and VB1 are equal, the controller 40 determines in step S207 that at least one of the system main relays SMR-P and SMR-C is fixed.

  When the process of step S206 is performed, the system main relay SMR-B remains on. Therefore, if at least one of the system main relays SMR-P and SMR-C is fixed, the discharge current of the first battery group 10A Thus, the first capacitor C1 is charged. As a result, the voltage value of the first capacitor C1 becomes equal to the voltage value VB1 of the first battery group 10A. Here, the voltage sensor 23 can detect the voltage value of the first capacitor C1 using the current path indicated by the dotted line in FIG. 6, and the voltage value VL is equal to the voltage value VB1.

  Here, if the second diode D2 is omitted, the voltage value VL becomes 0 [V] as described with reference to FIG. Even when all the system main relays SMR-B, SMR-G, SMR-P, and SMR-C are off, the voltage value VL becomes 0 [V], so that the system main relay is based on the voltage value VL. It cannot be determined whether SMR-P and SMR-C are fixed. According to the present embodiment, by providing the second diode D2, the voltage value VL indicates the voltage value VB1 according to the fixation of the system main relays SMR-P and SMR-C. Therefore, based on the voltage value VL, It is possible to determine whether the system main relays SMR-P and SMR-C are stuck.

  When the voltage values VL and VB1 are different, the controller 40 determines that the system main relays SMR-P and SMR-C are not fixed. If the system main relays SMR-P and SMR-C are not fixed, the voltage value VL becomes substantially 0 [V], and the voltage values VL and VB1 are different. After determining that the system main relays SMR-P and SMR-C are not fixed, the controller 40 outputs a control signal for turning off the system main relay SMR-B in step S208. If the system main relay SMR-B is not fixed, it receives a control signal from the controller 40 and switches from on to off. When the process of step S208 is completed, the battery system is stopped.

  When it is determined that the system main relay SMR-G is fixed by the process of step S205, or it is determined that the system main relays SMR-P and SMR-C are fixed by the process of step S207, The controller 40 can perform the warning described above. Further, when it is determined that the system main relay SMR-G and the system main relays SMR-P and SMR-C are fixed, it is possible to prevent the vehicle from starting next time.

  On the other hand, the process shown in FIG. 8 can be performed instead of the process shown in FIG. 8, the same processes as those described in FIG. 7 are denoted by the same reference numerals, and detailed description thereof is omitted. Hereinafter, differences from the processing illustrated in FIG. 7 will be mainly described.

  When the controller 40 determines that the system main relay SMR-G is not fixed by the process of step S204, the controller 40 performs the process of step S209. In step S209, the controller 40 determines whether or not the voltage value VL is equal to or lower than the reference voltage value V0. Here, the reference voltage value V0 can be set to 0 [V], or can be set to a value higher than 0 [V] in consideration of the detection error of the voltage sensor 23. Information for specifying the reference voltage value V0 can be stored in the memory 41.

  When the voltage value VL is equal to or lower than the reference voltage value V0, the controller 40 determines that the system main relays SMR-P and SMR-C are not fixed, and performs the process of step S208. On the other hand, when the voltage value VL is higher than the reference voltage value V0, the controller 40 determines in step S207 that at least one of the system main relays SMR-P and SMR-C is fixed. As described with reference to FIG. 7, when the system main relays SMR-P and SMR-C are fixed, the voltage values VL and VB1 are equal, and the voltage value VL is higher than the reference voltage value V0.

  In the process of step S202 shown in FIG. 7 or FIG. 8, instead of outputting a control signal for turning off the system main relay SMR-G, a control signal for turning off the system main relay SMR-B is sent. Can be output. In this case, it can be determined in step S205 that the system main relay SMR-B is fixed. In the process of step S208, a control signal for turning off the system main relay SMR-G can be output instead of outputting a control signal for turning off the system main relay SMR-B.

  Here, in the process of step S206 shown in FIG. 7, instead of determining whether or not the voltage values VL and VB1 are equal, it is determined whether or not the voltage values VL and VB2 are equal. When system main relay SMR-G is on and at least one of system main relays SMR-C and SMR-P is fixed, second capacitor C2 is charged by the discharge current of second battery group 10B. As a result, the voltage value of the second capacitor C2 becomes equal to the voltage value VB2 of the second battery group 10B.

  Further, since the voltage sensor 23 can detect the voltage value of the second capacitor C2 using the current path indicated by the dotted line in FIG. 5, the voltage values VL and VB2 are equal. Therefore, it can be determined that at least one of the system main relays SMR-C and SMR-P is fixed by confirming that the voltage values VL and VB2 are equal.

  Here, if the first diode D1 is omitted, as described with reference to FIG. 23, the voltage value VL becomes 0 [V], and it is determined whether or not the system main relays SMR-P and SMR-C are fixed. Can not. According to the present embodiment, by providing the first diode D1, the voltage value VL indicates the voltage value VB2 corresponding to the fixation of the system main relays SMR-P and SMR-C. Therefore, based on the voltage value VL, It is possible to determine whether the system main relays SMR-P and SMR-C are stuck.

  According to the present embodiment, all the system main relays SMR-B, SMR-G, SMR-P, and SMR- are performed by performing the processing shown in FIG. 3 or 4 and the processing shown in FIG. 7 or FIG. In C, it can be determined whether or not sticking has occurred.

  Further, according to the present embodiment, it is possible to determine whether the system main relays SMR-B, SMR-G, SMR-P, and SMR-C are fixed based on the detection result of the voltage sensor 23. Therefore, it is not necessary to detect the voltage value of the first capacitor C1 or the voltage value of the second capacitor C2 in order to determine whether the system main relays SMR-C, SMR-P, etc. are fixed. There is no need to add a new voltage sensor. In the present embodiment, diodes D1 and D2 are added to the configuration shown in FIG. 22, but the diodes D1 and D2 are usually cheaper than voltage sensors, so compared to the case where a voltage sensor is added. Thus, an increase in cost can be suppressed.

  A battery system that is Embodiment 2 of the present invention will be described. FIG. 9 shows the configuration of the battery system of this example. About the same member as the member demonstrated in Example 1, the same code | symbol is used and detailed description is abbreviate | omitted. Hereinafter, differences from the first embodiment will be mainly described.

  In the first embodiment, the resistance element R and the system main relay SMR-P are connected in parallel to the system main relay SMR-C. However, in this embodiment, the resistance to the system main relay SMR-C is The element R and the system main relay SMR-P are not connected in parallel.

  On the other hand, resistance element R1 and system main relay SMR-P1 are connected in parallel to system main relay SMR-B, and resistance element R1 and system main relay SMR-P1 are connected in series. The resistance element R1 has the same function as the resistance element R described in the first embodiment. System main relay SMR-P1 receives a control signal from controller 40 and switches between on and off.

  Further, the resistance element R2 and the system main relay SMR-P2 are connected in parallel to the system main relay SMR-G, and the resistance element R2 and the system main relay SMR-P2 are connected in series. The resistance element R2 has the same function as the resistance element R described in the first embodiment. System main relay SMR-P2 receives a control signal from controller 40 and switches between on and off.

  Next, processing when starting the battery system of the present embodiment will be described with reference to the flowchart shown in FIG. The process shown in FIG. 10 is started when the ignition switch is switched from OFF to ON, and is executed by the controller 40. When the processing shown in FIG. 10 is started, the system main relays SMR-B, SMR-G, SMR-C, SMR-P1, and SMR-P2 are turned off.

  In step S301, the controller 40 outputs a control signal for turning on the system main relays SMR-C and SMR-P2. System main relays SMR-C and SMR-P2 are switched from off to on in response to a control signal from controller 40. In step S302, the controller 40 determines whether or not the voltage value VL is equal to or higher than the voltage value VBt.

  When voltage value VL is equal to or higher than voltage value VBt, controller 40 determines in step S303 that at least one of system main relays SMR-B and SMR-P1 is fixed. When at least one of system main relays SMR-B and SMR-P1 is fixed, capacitors C1 and C2 are charged by the discharge current of battery pack 10, and voltage values VL and VBt become equal. Therefore, by confirming that the voltage value VL is equal to or higher than the voltage value VBt, it can be determined that at least one of the system main relays SMR-B and SMR-P1 is fixed.

  When voltage value VL is lower than voltage value VBt, controller 40 can determine that system main relays SMR-B and SMR-P1 are not fixed. If the system main relays SMR-B and SMR-P1 are not fixed, the voltage value VL indicates the voltage value VB2 as in the case described with reference to FIG. That is, since voltage value VL becomes lower than voltage value VBt, it can be determined that system main relays SMR-B and SMR-P1 are not fixed.

  In step S304, a control signal for turning on system main relay SMR-P1 is output. System main relay SMR-P1 is switched from off to on in response to a control signal from controller 40. In step S305, the controller 40 outputs a control signal for turning on the system main relays SMR-B and SMR-G. System main relays SMR-B and SMR-G are switched from off to on in response to a control signal from controller 40.

  In step S306, the controller 40 outputs a control signal for turning off the system main relays SMR-P1 and SMR-P2. System main relays SMR-P1 and SMR-P2 are switched from on to off in response to a control signal from controller 40 unless they are fixed. By ending the process of step S306, the battery system shown in FIG. 9 is activated.

  In the process of step S301, a control signal for turning on the system main relay SMR-P1 can be output instead of outputting a control signal for turning on the system main relay SMR-P2. In this case, in the process of step S304, a control signal for turning on the system main relay SMR-P2 is output.

  On the other hand, the process shown in FIG. 11 can be performed instead of the process shown in FIG. In step S401, the controller 40 outputs a control signal for turning on the system main relays SMR-P1 and SMR-P2. System main relays SMR-P1 and SMR-P2 are switched from off to on in response to a control signal from controller 40.

  In step S402, the controller 40 outputs a control signal for turning on the system main relay SMR-C. The system main relay SMR-C is switched from off to on in response to a control signal from the controller 40. Note that the processes of steps S401 and S402 may be performed simultaneously, or after the process of step S402 is performed, the process of step S401 may be performed.

  In step S403, the controller 40 outputs a control signal for turning on the system main relays SMR-B and SMR-G. System main relays SMR-B and SMR-G are switched from off to on in response to a control signal from controller 40. In step S404, the controller 40 outputs a control signal for turning off the system main relays SMR-P1 and SMR-P2. System main relays SMR-P1 and SMR-P2 are switched from on to off in response to a control signal from controller 40 unless they are fixed. By ending the process of step S404, the battery system shown in FIG. 9 is activated.

  According to the process shown in FIG. 11, the battery main system SMR-P1 and SMR-P2 are operated at the same time, so that the battery system is operated compared to when the system main relays SMR-P1 and SMR-P2 are operated at different timings. It is possible to shorten the time until the is activated. Further, by operating system main relays SMR-B and SMR-G at the same time, the system main relays SMR-B and SMR-G can be operated in a starting state as compared to when system main relays SMR-B and SMR-G are operated at different timings. Time can be shortened.

  Further, if the two movable contacts in the system main relays SMR-P1 and SMR-P2 are mechanically connected, the system main relays SMR-P1 and SMR-P2 can be operated using one drive circuit. it can. The same applies to the system main relays SMR-B and SMR-G.

  Next, processing when the battery system shown in FIG. 9 is stopped will be described with reference to the flowchart shown in FIG. The process shown in FIG. 12 is started when the ignition switch is switched from on to off, and is executed by the controller 40. When the processing shown in FIG. 12 is started, the system main relays SMR-B, SMR-C, and SMR-G are turned on.

  In step S501, the controller 40 outputs a control signal for turning off the system main relay SMR-C. In step S502, the controller 40 outputs a control signal for turning off the system main relay SMR-G. The processing in steps S501 and S502 is the same as the processing in steps S201 and S202 described with reference to FIG. In step S503, the controller 40 discharges the capacitors C1 and C2. The processing in step S503 is the same as the processing in step S203 described with reference to FIG.

  In step S504, the controller 40 determines whether or not the voltage values VL and VBt are equal. The processing in step S504 is the same as the processing in step S204 described with reference to FIG. When voltage values VL and VBt are equal, controller 40 determines in step S505 that at least one of system main relays SMR-G and SMR-P2 is fixed. When the voltage values VL and VBt are equal despite the control of turning off the system main relay SMR-G by the processing of step S502, at least one of the system main relays SMR-G and SMR-P2 is fixed. You can see that

  When the voltage values VL and VBt are different, the controller 40 can determine that the system main relays SMR-G and SMR-P2 are not fixed. When the system main relays SMR-C and SMR-G are turned off by the processing of steps S501 and S502, if the system main relays SMR-G and SMR-P2 are not fixed, the voltage value VL is approximately 0 [V Or the voltage value VL indicates the voltage value VB1, as will be described later. That is, since the voltage value VL is lower than the voltage value VBt and the voltage values VL and VBt are different, it can be determined that the system main relays SMR-G and SMR-P2 are not fixed.

  In step S506, it is determined whether or not the voltage values VL and VB1 are equal. The process in step S506 is the same as the process in step S206 described with reference to FIG. When the voltage values VL and VB1 are equal, the controller 40 determines in step S507 that the system main relay SMR-C is fixed. When system main relay SMR-C is fixed, first capacitor C1 is charged by the discharge current of first battery group 10A. Thereby, similarly to the case shown in FIG. 6, the voltage sensor 23 can detect the voltage value of the first capacitor C1, and the voltage values VL and VB1 become equal.

  When the voltage values VL and VB1 are different, the controller 40 determines that the system main relay SMR-C is not fixed, and performs the process of step S508. When system main relay SMR-C is not fixed, voltage value VL is equal to or lower than reference voltage value V0 (see step S209 in FIG. 8), and voltage values VL and VB1 are different. In step S508, the controller 40 outputs a control signal for turning off the system main relay SMR-B. If the system main relay SMR-B is not fixed, it receives a control signal from the controller 40 and switches from on to off. By terminating the process of step S508, the battery system shown in FIG. 9 is stopped.

  In the process of step S502 shown in FIG. 12, instead of outputting a control signal for turning off system main relay SMR-G, a control signal for turning off system main relay SMR-B is outputted. Can do. This process is referred to as a modification of the process shown in FIG.

  In the modification of the process shown in FIG. 12, it can be determined in the process of step S505 that at least one of the system main relays SMR-B and SMR-P1 is fixed. In the process of step S508, instead of outputting a control signal for turning off the system main relay SMR-B, a control signal for turning off the system main relay SMR-G can be outputted.

  Here, in the process of step S506 shown in FIG. 12, instead of determining whether or not the voltage values VL and VB1 are equal, it is determined whether or not the voltage values VL and VB2 are equal. The process of determining whether or not the voltage values VL and VB2 are equal is the same as the process of step S107 shown in FIG. When system main relay SMR-G is off and system main relay SMR-C is fixed, second capacitor C2 is charged by the discharge current of second battery group 10B. Thus, as in the case shown in FIG. 5, the voltage sensor 23 can detect the voltage value of the second capacitor C2, and the voltage values VL and VB2 are equal.

  When the processing shown in FIGS. 10 and 12 is performed, it is determined whether or not the fixing has occurred in all the system main relays SMR-B, SMR-G, SMR-C, SMR-P1, and SMR-P2. Can do. On the other hand, when the processing shown in FIGS. 11 and 12 is performed, it cannot be determined whether or not the system main relays SMR-B and SMR-P1 are fixed. However, by combining the process shown in FIG. 12 and a modification of the process shown in FIG. 12, all system main relays SMR-B, SMR-G, SMR-C, SMR-P1, and SMR-P2 are fixed. It is possible to determine whether or not the above has occurred. For example, the process shown in FIG. 12 and a modification of the process shown in FIG. 12 can be performed alternately.

  A battery system that is Embodiment 3 of the present invention will be described. The same members 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 and second embodiments will be mainly described.

  In the battery systems of Examples 1 and 2, one intermediate line ML is provided, but a plurality of intermediate lines ML may be provided. For example, as shown in FIG. 13, two intermediate lines ML1 and ML2 can be provided.

  The assembled battery 10 shown in FIG. 13 has three battery groups 10A to 10C connected in series. Here, the voltage sensor 24 detects the voltage value of the third battery group 10 </ b> C and outputs the detection result to the controller 40. Capacitors C1, C3, and C2 are connected in series between positive electrode line PL and negative electrode line NL.

  The first intermediate line ML1 is connected to a connection point between the battery groups 10A and 10C and a connection point between the capacitors C1 and C3. The first main line ML1 is provided with a system main relay SMR-C1, and the system main relay SMR-C1 is switched between on and off in response to a control signal from the controller 40.

  The second intermediate line ML2 is connected to the connection point of the battery groups 10C and 10B and the connection point of the capacitors C3 and C2. The second intermediate line ML2 is provided with a system main relay SMR-C2. The system main relay SMR-C2 is switched between on and off in response to a control signal from the controller 40. System main relays SMR-C1 and SMR-C2 correspond to system main relay SMR-C shown in FIG. 1 or FIG.

  The anode of the first diode D1 is connected to the first intermediate line ML1, and the cathode of the second diode D2 is connected to the second intermediate line ML2. The cathode of the third diode D3 is connected to the first intermediate line ML1, and the anode of the third diode D3 is connected to the second intermediate line ML2. Here, the connection positions of the diodes D1 to D3 with respect to the intermediate lines ML1 and ML2 are the same as those described in the first embodiment.

  Here, although not shown in FIG. 13, similar to the configuration shown in FIG. 1, the resistance element R and the system main relay SMR-P are connected in parallel to at least one of the system main relays SMR-C1 and SMR-C2. Can be connected. Similarly to the configuration shown in FIG. 9, the resistance element R1 and the system main relay SMR-P1 are connected in parallel to the system main relay SMR-B, and the resistance element is connected to the system main relay SMR-G. R2 and system main relay SMR-P2 can be connected in parallel.

  In the battery system shown in FIG. 13, when any of system main relays SMR-B and SMR-G is on, system main relays SMR-C1 and SMR-C2 are fixed based on the detection result of voltage sensor 23. It can be determined whether or not.

  Specifically, when the system main relay SMR-B is on, if the voltage value VL is equal to the voltage value VB1 of the first battery group 10A, it can be determined that the system main relay SMR-C1 is fixed. Further, when the voltage value VL is equal to the total voltage value of the battery groups 10A and 10C, it can be determined that the system main relay SMR-C2 is fixed.

  On the other hand, when the system main relay SMR-G is on, if the voltage value VL is equal to the voltage value VB2 of the second battery group 10B, it can be determined that the system main relay SMR-C2 is fixed. Further, when the voltage value VL is equal to the total voltage value of the battery groups 10B and 10C, it can be determined that the system main relay SMR-C1 is fixed.

  In the battery system shown in FIG. 13, when any one of system main relays SMR-C1 and SMR-C2 is on, system main relays SMR-B and SMR-G are fixed based on the detection result of voltage sensor 23. It can be determined whether or not.

  Specifically, when the system main relay SMR-C1 is on, if the voltage value VL is equal to the voltage value VB1 of the first battery group 10A, it can be determined that the system main relay SMR-B is fixed. Further, when the voltage value VL is equal to the total voltage value of the battery groups 10B and 10C, it can be determined that the system main relay SMR-G is fixed.

  On the other hand, when the system main relay SMR-C2 is on, if the voltage value VL is equal to the voltage value VB2 of the second battery group 10B, it can be determined that the system main relay SMR-G is fixed. Further, when the voltage value VL is equal to the total voltage value of the battery groups 10A and 10C, it can be determined that the system main relay SMR-B is fixed.

  Even when three or more intermediate lines ML are provided, whether the system main relays SMR-B and SMR-G are fixed based on the detection result of the voltage sensor 23 as in the present embodiment. Or whether the system main relay SMR-C provided in the intermediate line ML is fixed or not can be determined.

  The method for determining whether or not the system main relay SMR (SMR-B, SMR-G, SMR-C, etc.) is fixed is not limited to the method described in the first to third embodiments. That is, the controller 40 may control the system main relay SMR to be determined to be stuck off and monitor the voltage value VL when the other system main relay SMR is turned on. Based on the relationship between the voltage value VL and the voltage value of each battery group, it is possible to determine whether the system main relay SMR is stuck.

  For example, in the battery system described in the first embodiment, it is confirmed that the system main relay SMR-G is off, and when the system main relays SMR-B and SMR-C are on, the system main relay SMR-B is turned on. By performing the control to turn off, it is possible to determine whether the system main relay SMR-B is stuck based on the voltage value VL. Here, if the voltage values VL and VB1 are equal, it can be determined that the system main relay SMR-B is fixed.

  Further, it is confirmed that the system main relay SMR-B is turned off, and when the system main relays SMR-G and SMR-C are turned on, the system main relay SMR-G is controlled to be turned off. Based on the value VL, it is possible to determine whether the system main relay SMR-G is stuck. Here, if the voltage values VL and VB2 are equal, it can be determined that the system main relay SMR-G is fixed.

Also in the battery system described in the second embodiment, it is possible to determine whether the system main relays SMR-B and SMR-P1 are fixed or to determine whether the system main relays SMR-G and SMR-P2 are fixed by the same method as above. Can be.
(Reference Example 1)

  The battery system which is the reference example 1 is demonstrated using FIG. In this reference example, the same members as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this reference example, in the battery system shown in FIG. 1 or FIG. 9, a voltage sensor 25 is provided instead of the first diode D1, and a voltage sensor 26 is provided instead of the second diode D2. In FIG. 14, system main relay SMR-P and resistance element R shown in FIG. 1 are omitted, and system main relays SMR-P1, SMR-P2 and resistance elements R1, R2 shown in FIG. 9 are omitted.

  The voltage sensor 25 detects the voltage value VC1 of the first capacitor C1 and outputs the detection result to the controller 40. The voltage sensor 26 detects the voltage value VC2 of the second capacitor C2 and outputs the detection result to the controller 40. In this reference example, the voltage sensor 23 shown in FIG. 1 or FIG. 9 is omitted.

  Next, in the present reference example, processing for determining whether the system main relays SMR-B, SMR-G, and SMR-C are fixed will be described with reference to the flowchart shown in FIG. The process shown in FIG. 15 is executed by the controller 40 and can be performed, for example, before starting the battery system. When the processing shown in FIG. 15 is started, the system main relays SMR-B, SMR-G, and SMR-C are turned off.

  In step S601, the controller 40 outputs a control signal for turning on the system main relay SMR-B. System main relay SMR-B is switched from off to on in response to a control signal from controller 40. Here, as shown in FIG. 9, when the system main relay SMR-P1 is connected in parallel to the system main relay SMR-B, at least one of the system main relays SMR-B and SMR-P1 is turned on. The control signal can be output.

  In step S602, the controller 40 determines whether or not the voltage values VC1 and VB1 are equal. Here, it is also possible to determine whether or not the condition shown in the following formula (4) is satisfied in consideration of variations in the voltage values VC1 and VB1.

  The constant α4 shown in the above equation (4) is a value that allows variations in the voltage values VC1 and VB1 (a value larger than 0), and can be set as appropriate in consideration of variations in the voltage values VC1 and VB1. When the condition shown in the above equation (4) is satisfied, it can be determined that the voltage values VC1 and VB1 are equal. Further, when the condition shown in the above equation (4) is not satisfied, it can be determined that the voltage values VC1 and VB1 are different.

  When voltage values VC1 and VB1 are equal, controller 40 determines in step S603 that system main relay SMR-C is fixed. When system main relay SMR-C is fixed, first capacitor C1 is charged by the discharge current of first battery group 10A, and voltage values VC1 and VB1 become equal. Therefore, it can be determined that the system main relay SMR-C is fixed by confirming that the voltage values VC1 and VB1 are equal.

  Here, as shown in FIG. 1, when the system main relay SMR-P is connected in parallel to the system main relay SMR-C, the system main relays SMR-C, SMR-P are processed in step S603. It can be determined that at least one of the two is fixed. When the voltage values VC1 and VB1 are different, the controller 40 can determine that the system main relay SMR-C is not fixed. That is, when the system main relay SMR-C is not fixed, the voltage value VC1 indicates substantially 0 [V], and the voltage values VC1 and VB1 are different. Substantially 0 [V] means that a detection error of the voltage sensor 25 is included.

  In step S604, a control signal for turning off system main relay SMR-B is output. If the system main relay SMR-B is not fixed, it receives a control signal from the controller 40 and switches from on to off.

  In step S605, the controller 40 outputs a control signal for turning on the system main relay SMR-C. The system main relay SMR-C is switched from off to on in response to a control signal from the controller 40. Here, as shown in FIG. 1, when the system main relay SMR-P is connected in parallel to the system main relay SMR-C, at least one of the system main relays SMR-C and SMR-P is turned on. The control signal can be output.

  In step S606, the controller 40 determines whether or not the voltage values VC1 and VB1 are equal. The process in step S606 is the same as the process in step S602. When voltage values VC1 and VB1 are equal, controller 40 determines in step S607 that system main relay SMR-B is fixed. When system main relay SMR-C is on, if system main relay SMR-B is fixed, first capacitor C1 is charged by the discharge current of first battery group 10A, and voltage values VC1 and VB1 are equal. Become.

  Therefore, it can be determined that the system main relay SMR-B is fixed by confirming that the voltage values VC1 and VB1 are equal. Here, as shown in FIG. 9, when the system main relay SMR-P1 is connected in parallel to the system main relay SMR-B, at least one of the system main relays SMR-B and SMR-P1 is processed in step S607. It can be determined that one of them is fixed.

  When the voltage values VC1 and VB1 are different, the controller 40 determines that the system main relay SMR-B is not fixed, and determines whether or not the voltage values VC2 and VB2 are equal in step S608. Here, it is also possible to determine whether or not the condition shown in the following equation (5) is satisfied in consideration of variations in the voltage values VC2 and VB2.

  The constant α5 shown in the above equation (5) is a value that allows variations in the voltage values VC2 and VB2 (a value greater than 0), and can be set as appropriate in consideration of variations in the voltage values VC2 and VB2. When the condition shown in the above equation (5) is satisfied, it can be determined that the voltage values VC2 and VB2 are equal. Further, when the condition shown in the above equation (5) is not satisfied, it can be determined that the voltage values VC2 and VB2 are different.

  When the voltage values VC2 and VB2 are equal, the controller 40 determines in step S609 that the system main relay SMR-G is fixed. When system main relay SMR-C is on, if system main relay SMR-G is fixed, second capacitor C2 is charged by the discharge current of second battery group 10B, and voltage values VC2 and VB2 become equal. .

  Therefore, it can be determined that the system main relay SMR-G is fixed by confirming that the voltage values VC2 and VB2 are equal. Here, as shown in FIG. 9, when the system main relay SMR-P2 is connected in parallel to the system main relay SMR-G, at least the system main relays SMR-G and SMR-P2 are processed in step S609. It can be determined that one of them is fixed.

  When the voltage values VC2 and VB2 are different, the controller 40 determines that the system main relay SMR-G is not fixed, and ends the process shown in FIG. If system main relay SMR-G is not fixed, voltage value VC2 indicates approximately 0 [V], and voltage values VC2 and VB2 are different. Substantially 0 [V] means that a detection error of the voltage sensor 26 is included. By performing the processing shown in FIG. 15, it is possible to determine whether all the system main relays SMR-B, SMR-G, and SMR-C are stuck.

  In the process of step S601 shown in FIG. 15, instead of outputting a control signal for turning on system main relay SMR-B, a control signal for turning on system main relay SMR-G is outputted. Can do. In this case, in the process of step S604, a control signal for turning off the system main relay SMR-G may be output. Here, as shown in FIG. 9, when the system main relay SMR-P2 is connected in parallel to the system main relay SMR-G, at least one of the system main relays SMR-G and SMR-P2 is turned on or off. A control signal can be output.

  Further, the order of determining whether the system main relays SMR-B, SMR-G, and SMR-C are fixed is not limited to the order shown in FIG. Even if the processing order described with reference to FIG. 15 is changed, it is possible to determine whether the system main relays SMR-B, SMR-G, and SMR-C are stuck. For example, after performing the process of step S605-step S609, the process of step S601-step S603 can also be performed.

  According to the invention obtained from this reference example, the power storage system includes a power storage device, a capacitor, and a relay. The power storage device is connected to a load via a positive electrode line and a negative electrode line, and includes a first power storage group and a second power storage group connected in series. Each of the first power storage group and the second power storage group includes a plurality of power storage elements connected in series, and each power storage element includes a current breaker that interrupts a current path of the power storage elements.

  An intermediate line is connected to the connection point of the first power storage group and the second power storage group. The capacitor includes a first capacitor connected to the positive electrode line and the intermediate line, and a second capacitor connected to the negative electrode line and the intermediate line. The relay is provided in each of the positive electrode line, the negative electrode line, and the intermediate line.

The first voltage sensor (corresponding to the voltage sensor 25) is connected to the positive line and the intermediate line, detects the voltage value of the first capacitor, and outputs the detection result to the controller. The second voltage sensor (corresponding to the voltage sensor 26) is connected to the negative electrode line and the intermediate line, detects the voltage value of the second capacitor, and outputs the detection result to the controller. The controller determines whether or not each relay is fixed based on the detection results of the first voltage sensor and the second voltage sensor while controlling on and off of each relay.
(Reference example 2)

  The battery system which is the reference example 2 is demonstrated using FIG. In this reference example, the same members as those described in Example 1 and Reference Example 1 are denoted by the same reference numerals, and detailed description thereof is omitted. In this reference example, differences from Example 1 and Reference Example 1 will be mainly described.

  In this reference example, in the battery system shown in FIG. 1 or FIG. 9, the voltage sensor 25 is provided instead of the first diode D1, and the second diode D2 is omitted. In FIG. 16, system main relay SMR-P and resistance element R shown in FIG. 1 are omitted, and system main relays SMR-P1, SMR-P2 and resistance elements R1, R2 shown in FIG. 9 are omitted.

  Next, in this reference example, processing for determining whether the system main relays SMR-B, SMR-G, and SMR-C are fixed will be described with reference to the flowchart shown in FIG. In the process shown in FIG. 17, the same processes as those described in FIG. 15 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this reference example, the process of step S610 is performed instead of the process of step S608 shown in FIG. In step S610, the controller 40 determines whether or not the sum of the voltage values VL and VC1 is equal to the voltage value VB2. Here, it is also possible to determine whether or not the condition shown in the following equation (6) is satisfied in consideration of variations in the voltage values VC1, VL, and VB2.

  The constant α6 shown in the above equation (6) is a value that allows variations in the voltage values VC1, VL, and VB2 (a value greater than 0), and is appropriately set in consideration of variations in the voltage values VC1, VL, and VB2. be able to. When the condition shown in the above equation (6) is satisfied, it can be determined that the sum of the voltage values VL and VC1 is equal to the voltage value VB2. Further, when the condition shown in the above equation (6) is not satisfied, it can be determined that the sum of the voltage values VL and VC1 is different from the voltage value VB2.

  When the sum of the voltage values VL and VC1 is equal to the voltage value VB2, the controller 40 determines in step S609 that the system main relay SMR-G is fixed. When system main relay SMR-C is on and system main relay SMR-G is fixed, second capacitor C2 is charged by the discharge current of second battery group 10B.

  When charges are accumulated in the second capacitor C2, a closed circuit is formed in the path indicated by the dotted line in FIG. In the closed circuit indicated by the dotted line in FIG. 18, the voltage value of the second capacitor C2 corresponds to the sum of the voltage values VL and VC1. Therefore, if it is confirmed that the sum of the voltage values VL and VC1 is equal to the voltage value VB2, it can be determined that the system main relay SMR-G is fixed.

  On the other hand, if the system main relay SMR-G is not fixed, the voltage values VL and VC1 indicate substantially 0 [V]. For this reason, the sum of the voltage values VL and VC1 also shows substantially 0 [V], and the sum of the voltage values VL and VC1 is different from the voltage value VB2. Therefore, if the sum of the voltage values VL and VC1 is different from the voltage value VB2, it can be understood that the second capacitor C2 is not charged by the discharge current of the second battery group 10B, and the system main relay SMR-G is fixed. Can be determined.

  According to the invention obtained from this reference example, the power storage system includes a power storage device, a capacitor, and a relay. The power storage device is connected to a load via a positive electrode line and a negative electrode line, and includes a first power storage group and a second power storage group connected in series. Each of the first power storage group and the second power storage group includes a plurality of power storage elements connected in series, and each power storage element includes a current breaker that interrupts a current path of the power storage elements.

  An intermediate line is connected to the connection point of the first power storage group and the second power storage group. The capacitor includes a first capacitor connected to the positive electrode line and the intermediate line, and a second capacitor connected to the negative electrode line and the intermediate line. The relay is provided in each of the positive electrode line, the negative electrode line, and the intermediate line.

The first voltage sensor (corresponding to the voltage sensor 25) is connected to the positive line and the intermediate line, detects the voltage value of the first capacitor, and outputs the detection result to the controller. The second voltage sensor (corresponding to the voltage sensor 23) is connected to the positive electrode line and the negative electrode line, detects the voltage value between the positive electrode line and the negative electrode line, and outputs the detection result to the controller. The controller determines whether or not each relay is fixed based on the detection results of the first voltage sensor and the second voltage sensor while controlling on and off of each relay.
(Reference Example 3)

  The battery system which is the reference example 3 is demonstrated using FIG. In this reference example, the same members as those described in Example 1 and Reference Example 1 are denoted by the same reference numerals, and detailed description thereof is omitted. In this reference example, differences from Example 1 and Reference Example 1 will be mainly described.

  In this reference example, in the battery system shown in FIG. 1 or FIG. 9, the voltage sensor 26 is provided instead of the second diode D2, and the first diode D1 is omitted. In FIG. 19, system main relay SMR-P and resistance element R shown in FIG. 1 are omitted, and system main relays SMR-P1, SMR-P2 and resistance elements R1, R2 shown in FIG. 9 are omitted.

  Next, in this reference example, processing for determining whether the system main relays SMR-B, SMR-G, and SMR-C are fixed will be described with reference to the flowchart shown in FIG. In the processing shown in FIG. 20, the same processing as that described in FIG. 15 is denoted by the same reference numeral, and detailed description thereof is omitted.

  In this reference example, the process of step S611 is performed instead of the process of step S602 shown in FIG. In step S611, the controller 40 determines whether or not the sum of the voltage values VL and VC2 is equal to the voltage value VB1. Here, it is also possible to determine whether or not the condition shown in the following equation (7) is satisfied in consideration of variations in the voltage values VC2, VL, and VB1.

  The constant α7 shown in the above equation (7) is a value that allows variations in the voltage values VC2, VL, and VB1 (a value greater than 0), and is appropriately set in consideration of variations in the voltage values VC2, VL, and VB1. be able to. When the condition shown in the above equation (7) is satisfied, it can be determined that the sum of the voltage values VL and VC2 is equal to the voltage value VB1. Further, when the condition shown in the above equation (7) is not satisfied, it can be determined that the sum of the voltage values VL and VC2 is different from the voltage value VB1.

  When the sum of the voltage values VL and VC2 is equal to the voltage value VB1, the controller 40 determines in step S603 that the system main relay SMR-C is fixed. When system main relay SMR-B is on and system main relay SMR-C is fixed, first capacitor C1 is charged by the discharge current of first battery group 10A. When charges are accumulated in the first capacitor C1, a closed circuit is formed in the path indicated by the dotted line in FIG.

  In the closed circuit indicated by the dotted line in FIG. 21, the voltage value of the first capacitor C1 corresponds to the sum of the voltage values VL and VC2. If it is confirmed that the sum of the voltage values VL and VC2 is equal to the voltage value VB1, it can be determined that the system main relay SMR-C is fixed. When the sum of the voltage values VL and VC2 is different from the voltage value VB1, the controller 40 determines that the system main relay SMR-C is not fixed, and performs the processing after step S604.

  Further, in this reference example, the process of step S612 is performed instead of the process of step S606 shown in FIG. The process in step S612 is the same as the process in step S611. When the system main relay SMR-C is turned on by the process of step S605, if the system main relay SMR-B is fixed, the first capacitor C1 is charged by the discharge current of the first battery group 10A.

  Here, if it is confirmed that the sum of the voltage values VL and VC2 is equal to the voltage value VB1, the controller 40 can determine in step S607 that the system main relay SMR-B is fixed. On the other hand, when the sum of the voltage values VL and VC2 is different from the voltage value VB1, the controller 40 can determine that the system main relay SMR-B is not fixed and perform the process of step S608.

  According to the invention obtained from this reference example, the power storage system includes a power storage device, a capacitor, and a relay. The power storage device is connected to a load via a positive electrode line and a negative electrode line, and includes a first power storage group and a second power storage group connected in series. Each of the first power storage group and the second power storage group includes a plurality of power storage elements connected in series, and each power storage element includes a current breaker that interrupts a current path of the power storage elements.

  An intermediate line is connected to the connection point of the first power storage group and the second power storage group. The capacitor includes a first capacitor connected to the positive electrode line and the intermediate line, and a second capacitor connected to the negative electrode line and the intermediate line. The relay is provided in each of the positive electrode line, the negative electrode line, and the intermediate line.

  The first voltage sensor (corresponding to the voltage sensor 26) is connected to the negative electrode line and the intermediate line, detects the voltage value of the second capacitor, and outputs the detection result to the controller. The second voltage sensor (corresponding to the voltage sensor 23) is connected to the positive electrode line and the negative electrode line, detects the voltage value between the positive electrode line and the negative electrode line, and outputs the detection result to the controller. The controller determines whether or not each relay is fixed based on the detection results of the first voltage sensor and the second voltage sensor while controlling on and off of each relay.

10: assembled battery (power storage device), 10A: first battery group (first power storage group),
10B: 2nd battery group (2nd electrical storage group), 11: Single cell (electric storage element),
11a: power generation element, 11b: current breaker, 21-23: voltage sensor,
40: Controller, PL: Positive line, NL: Negative line, ML: Intermediate line,
C1: first capacitor, C2: second capacitor, D1: first diode,
D2: second diode,
SMR-B, SMR-G, SMR-P, SMR-C: System main relay

Claims (6)

A first power storage group including a plurality of power storage elements connected in series, each including a current breaker that interrupts a current path;
A second power storage group including a plurality of power storage elements connected in series, each comprising the current breaker;
A power storage device that is connected to a load via a positive electrode line and a negative electrode line and includes the first power storage group and the second power storage group connected in series,
An intermediate line connected to a connection point of the first power storage group and the second power storage group;
A first capacitor connected to the positive line and the intermediate line;
A second capacitor connected to the negative line and the intermediate line;
A voltage sensor for detecting a voltage value between the positive electrode line and the negative electrode line;
Relays provided in each of the positive line, the negative line and the intermediate line;
A cathode is connected to the positive line between the relay and the first capacitor on the positive line, and an anode is connected to the intermediate line between the relay and the first capacitor on the intermediate line. A diode,
A cathode is connected to the intermediate line between the relay and the second capacitor on the intermediate line, and an anode is connected to the negative line between the relay and the second capacitor on the negative line. A diode,
A controller for controlling on and off of each of the relays,
The controller is
When the relay on the positive line or the negative line and the relay on the intermediate line are on, control to turn off one of these relays,
When the voltage value detected by the voltage sensor is higher than a reference voltage value when the first capacitor and the second capacitor are not charged, it is determined that the relay controlled to be off is stuck. A power storage system characterized by that. The controller is
When the relay on the positive line and the intermediate line is on and the relay on the negative line is off, the relay on the intermediate line is turned off,
When the voltage value detected by the voltage sensor is equal to the voltage value of the first storage group higher than the reference voltage value, it is determined that the relay on the intermediate line is fixed. The power storage system according to claim 1. The controller is
When the relay on the positive line is off, and when the relay on the negative line and the intermediate line is on, control to turn off the relay on the intermediate line,
When the voltage value detected by the voltage sensor is equal to the voltage value of the second power storage group higher than the reference voltage value, it is determined that the relay on the intermediate line is fixed. The power storage system according to claim 1.   The relay on the intermediate line includes two relays connected in parallel, and a resistance element is connected in series to one of these relays. The electricity storage system described in 1. The relay on the positive line includes two relays connected in parallel, and one of these relays has a resistance element connected in series,
The relay on the negative line includes two relays connected in parallel, and one of these relays has a resistance element connected in series.
The power storage system according to any one of claims 1 to 3. The intermediate line includes a first intermediate line to which the first capacitor and the first diode are connected, and a second intermediate line to which the second capacitor and the second diode are connected.
A capacitor connected to the first intermediate line and the second intermediate line;
A diode having a cathode connected to the first intermediate line and an anode connected to the second intermediate line;
The power storage system according to any one of claims 1 to 5, wherein: