JP2014023278A - Power storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the operating state of a current breaker in a power storage block having a plurality of power storage elements connected in parallel.SOLUTION: A power storage system has a plurality of power storage blocks connected in series each having a plurality of power storage elements connected in parallel and a controller for determining the state of each of the power storage blocks. The power storage elements each have a current breaker for cutting off a current path inside the power storage element. The controller sends, to the power storage blocks, a current which is smaller than a reference current value by which the current breaker is actuated and which has the magnitude of a current flowing, by reason that a prescribed number of current breakers inside the power storage block have been actuated, into one or more of the power storage elements whose current breaker is not actuated and rising above the reference current value to become large enough to actuate all of the non-actuated current breakers inside the power storage block, and determines, on the basis of the detected voltage or current value of the power storage block, the power storage block which has had its current breakers actuated.

Description

  The present invention relates to a power storage system that determines an operating state of a current breaker in a power storage block in which a plurality of power storage elements each having a current breaker are connected in parallel.

  In the assembled battery described in Patent Document 1, in a configuration in which a plurality of batteries are connected in parallel, a fuse is connected to each of the single cells connected in parallel. The fuse cuts off the current path by fusing when an excessive current flows. In the technique described in Patent Document 2, the operation of a current interrupt mechanism included in the battery is detected based on a change in the internal resistance of the battery.

JP 05-275116 A JP 2008-182779 A JP 2011-135657 A

  In a configuration in which a plurality of batteries are connected in parallel, the value of the current flowing through the battery in which the current breaker is not operating varies depending on the number of activations of the current breaker. Specifically, when the current breaker is activated, the value of the current flowing through the battery whose current breaker is not operating increases, and the current load on the battery whose current breaker is not activated increases.

  For this reason, when the current breaker is activated, the heat generation amount of other batteries that are not activated or the current load is increased, so that the current breaker is activated from the viewpoint of battery safety. It is preferable to take measures such as detecting the battery accurately and stopping the continuous use of the battery or replacing the battery in which the current breaker is activated.

  However, as in Patent Document 2, since the voltage behavior of the battery is monitored and compared with a reference voltage measured in advance, it is connected in parallel. There is a problem that it is difficult to detect the change between the voltage behavior when the breaker is activated and the voltage behavior when the current breaker is not activated, and the operation state of the current breaker cannot be accurately detected.

  The battery characteristics vary depending on the environmental temperature, manufacturing variations, battery deterioration, and the like. For this reason, the voltage behavior when the current breaker is activated and the voltage behavior due to the change in battery characteristics cannot be properly identified, and the operating state of the current breaker cannot be detected accurately.

  In addition, since the battery capacity of a plurality of batteries decreases due to the operation of the current breaker, it is conceivable to detect the operating state of the current breaker by monitoring the change in the SOC. If the number of operating devices is small, it is difficult to detect the change in the SOC, and it cannot be accurately detected whether or not the current breaker is operating.

  Therefore, the present invention accurately determines whether or not the current breaker is activated using a reference current value at which the current breaker operates in a storage block in which a plurality of storage elements each having a current breaker are connected in parallel. An object of the present invention is to provide a power storage system that can perform the above operation.

  The power storage system according to the first invention of the present application includes a plurality of power storage blocks and a controller that determines the state of each power storage block. The plurality of power storage blocks are connected in series, and each power storage block has a plurality of power storage elements connected in parallel. Each power storage element has a current breaker that blocks a current path inside the power storage element. The controller has a current smaller than a reference current value at which the current breaker is activated, and a current flowing into a storage element in which the current breaker is not activated when a predetermined number of current breakers are activated in the storage block is a reference current. The current breaker is activated based on the detected value of the voltage or current of the storage block. Is determined.

  According to the first invention of this application, when the current breaker of the power storage elements connected in parallel is activated, the current is concentrated on the remaining power storage elements where the current breaker is not activated, and the current breaker is not activated. The value of current flowing through the remaining power storage elements increases. For this reason, even if a current smaller than the reference current value at which the current breaker is activated flows through the storage block, it is not activated if the current breaker is already activated in the storage block. If a current larger than the reference current value flows to the current breaker, all the current breakers in the storage block are activated, and no current breaker is activated, the current breaker is A current smaller than the current value flows and the current breaker does not operate. For this reason, based on the detected value of the voltage or current of the storage block, it is possible to determine the storage block in which the current breaker is in an operating state.

It is a figure which shows the structure of a battery system. It is a figure which shows the structure of the cell of a high capacity type assembled battery. It is a figure for demonstrating the operation | movement discrimination | determination of the current circuit breaker of Example 1. FIG. It is a flowchart which shows the electric current breaker action | operation discrimination | determination process of Example 1. FIG. It is a figure explaining the modification which discriminate | determines the operating state of a current breaker.

  Examples of the present invention will be described below.

  The battery system in the present embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram showing a configuration of a battery system. The battery system of this embodiment is mounted on a vehicle. Vehicles include hybrid cars and electric cars. In the present embodiment, a hybrid vehicle is described as an example. However, for example, an electric vehicle including only a battery system (assembled battery) as a power source for running the vehicle may be used.

  The battery system includes a high-power assembled battery 10 and a high-capacity assembled battery 20 that are electrically connected in parallel. The positive terminal of the high-power assembled battery 10 and the inverter 31 are connected via a positive line (cable) PL1, and the negative terminal of the high-power assembled battery 10 and the inverter 31 are connected via a negative line (cable) NL1. Has been. A system main relay SMR-B1 is provided in the positive electrode line PL1, and a system main relay SMR-G1 is provided in the negative electrode line NL1. The inverter 31 converts the DC power supplied from the high-power assembled battery 10 into AC power.

  The positive terminal of the high-capacity assembled battery 20 and the inverter 31 are connected via a positive line (cable) PL2, and the negative terminal of the high-capacity assembled battery 20 and the inverter 31 are connected via a negative line (cable) NL2. Has been. A system main relay SMR-B2 is provided in the positive electrode line PL2, and a system main relay SMR-G2 is provided in the negative electrode line NL2. The inverter 31 converts the DC power supplied from the high-capacity assembled battery 20 into AC power.

  A motor / generator 32 (AC motor) is connected to the inverter 31, and the motor / generator 32 receives AC power supplied from the inverter 31 and generates kinetic energy for running the vehicle. The motor / generator 32 is connected to the wheels 33. An engine 34 is connected to the wheel 33, and kinetic energy generated by the engine 34 is transmitted to the wheel 33. As a result, the vehicle can be driven using the outputs of the assembled batteries 10 and 20 and the engine 34. The engine 34 can be started using the output of the high-power assembled battery 10.

  When the vehicle is decelerated or stopped, the motor / generator 32 converts kinetic energy generated during braking of the vehicle into electric energy (AC power). The inverter 31 converts AC power generated by the motor / generator 32 into DC power and supplies the DC power to the assembled batteries 10 and 20. Thereby, the assembled batteries 10 and 20 can store regenerative electric power.

  The controller 35 outputs a control signal to each of the inverter 31 and the motor / generator 32 to control driving of the inverter 31 and the motor / generator 32. Further, the controller 35 outputs a control signal to each of the system main relays SMR-B1, SMR-B2, SMR-G1, and SMR-G2, so that each system main relay SMR-B1, SMR-B2, SMR-G1. , SMR-G2 is switched between on and off.

  When the system main relays SMR-B1 and SMR-G1 are on, the high-power assembled battery 10 can be charged and discharged, and when the system main relays SMR-B1 and SMR-G1 are off, the high-power type The assembled battery 10 is not charged or discharged. When the system main relays SMR-B2, SMR-G2 are on, the high-capacity assembled battery 20 can be charged / discharged. When the system main relays SMR-B2, SMR-G2 are off, the high-capacity type The assembled battery 20 is not charged or discharged.

  In addition, although each assembled battery 10 and 20 of a present Example is directly connected to the inverter 31, it is not restricted to this. Specifically, a booster circuit can be disposed in a current path between at least one of the assembled batteries 10 and 20 and the inverter 31. Thus, the booster circuit can boost the output voltage in at least one of the assembled batteries 10 and 20 and supply the boosted power to the inverter 31. Further, the booster circuit can step down the output voltage of the inverter 31 and supply the power after the step-down to at least one of the assembled batteries 10 and 20.

  The vehicle according to the present embodiment includes not only the assembled batteries 10 and 20 but also the engine 34 as a power source for running the vehicle. Some engines 34 use gasoline, diesel fuel or biofuel.

  In the vehicle of the present embodiment, the vehicle can be run using only the output of the high-power assembled battery 10 or the output of the high-capacity assembled battery 20. This travel mode is referred to as an EV (Electric Vehicle) travel mode. For example, the high-capacity assembled battery 20 can be discharged and the vehicle can run until the state of charge (SOC) reaches near 0% from near 100%. The SOC is the ratio of the current charge capacity to the full charge capacity.

  After the SOC of the high-capacity assembled battery 20 reaches around 0%, the high-capacity assembled battery 20 can be charged using an external power source (external charging). The external power source is a power source provided separately from the vehicle outside the vehicle. For example, a commercial power source can be used as the external power source. When using a commercial power supply, a charger (not shown) that converts AC power into DC power is required. The charger can be provided outside the vehicle, separately from the vehicle, or can be added to the battery system shown in FIG.

  In addition, after the SOC of the high-capacity assembled battery 20 reaches around 0%, the high-power assembled battery 10 and the engine 34 can be used together to drive the vehicle. This travel mode is referred to as an HV (Hybrid Vehicle) travel mode. In the HV traveling mode, the vehicle can travel using not only the output of the engine 34 but also the output of the high-power assembled battery 10. At this time, the engine 34 and the high-power assembled battery 10 can be used in combination.

  Further, in the HV traveling mode, for example, charging / discharging of the high-power assembled battery 10 can be controlled such that the SOC of the high-power assembled battery 10 changes along a predetermined reference SOC. For example, when the SOC of the high-power assembled battery 10 is higher than the reference SOC, the high-power assembled battery 10 can be discharged to bring the SOC of the high-power assembled battery 10 closer to the reference SOC. Further, when the SOC of the high-power assembled battery 10 is lower than the reference SOC, the high-power assembled battery 10 can be charged to bring the SOC of the high-power assembled battery 10 close to the reference SOC.

  In the HV traveling mode, not only the high-power assembled battery 10 but also the high-capacity assembled battery 20 can be used. For example, when the traveling in the EV traveling mode is terminated, the capacity of the high capacity assembled battery 20 can be left and the high capacity assembled battery 20 can be discharged in the HV traveling mode. Further, in the HV traveling mode, the regenerative power can be stored in the high capacity assembled battery 20.

  As described above, the battery system of the present embodiment includes the two assembled batteries 10 and 20 used for vehicle travel. For example, the high-capacity assembled battery 20 can be used mainly in the EV travel mode. The high-power assembled battery 10 can be used mainly in the HV traveling mode.

  As shown in FIG. 1, the high-power assembled battery 10 includes a plurality of single cells 11 that are electrically connected in series. The single battery 11 is a secondary battery such as a nickel metal hydride battery or a lithium ion battery. An electric double layer capacitor (capacitor) can be used instead of the secondary battery.

  The number of single cells 11 constituting the high-power assembled battery 10 can be appropriately set in consideration of the required output of the high-power assembled battery 10 and the like. As the cell 11, for example, a so-called square cell can be used. A rectangular unit cell is a unit cell in which the outer shape of the battery is formed along a rectangular parallelepiped.

  The unit cell 11 has a battery case, and a power generation element that charges and discharges is accommodated inside the battery case. The power generation element includes 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 formed on the surface of the current collector plate. The negative electrode element has a current collector plate and a negative electrode active material layer formed on the surface of the current collector plate. The separator, the positive electrode active material layer, and the negative electrode active material layer contain an electrolytic solution. A solid electrolyte may be used instead of the electrolytic solution.

  As shown in FIG. 1, the high-power assembled battery 10 is provided with a monitoring unit 12. The monitoring unit 12 detects the voltage between the terminals of the high-power assembled battery 10 and the voltage of each unit cell 11 and outputs the detection result to the controller 35. The current sensor 13 is provided on the positive electrode line PL <b> 1, detects the current value flowing through the high-power assembled battery 10, and outputs the detection result to the controller 35.

  When the high-power assembled battery 10 is being discharged, a positive value can be used as the current value detected by the current sensor 13. Further, when charging the high-power assembled battery 10, a negative value can be used as the current value detected by the current sensor 13. The current sensor 13 only needs to detect the value of the current flowing through the high-power assembled battery 10, and can be provided not on the positive electrode line PL1 but on the negative electrode line NL1.

  As shown in FIG. 1, the high-capacity assembled battery 20 has a plurality of battery blocks (corresponding to power storage blocks) 21 connected in series. By connecting a plurality of battery blocks 21 in series, the output voltage of the high-capacity assembled battery 20 can be secured. Here, the number of battery blocks 21 can be appropriately set in consideration of the voltage required for the high-capacity assembled battery 20.

  Each battery block 21 has a plurality of single cells (corresponding to power storage elements) 22 connected in parallel. By connecting the plurality of single cells 22 in parallel, the full charge capacity of the battery block 21 (high-capacity assembled battery 20) can be increased. The number of single cells 22 constituting each battery block 21 can be appropriately set in consideration of the full charge capacity required for the high-capacity assembled battery 20.

  Since the plurality of battery blocks 21 are connected in series, an equal current flows through each battery block 21. In each battery block 21, a plurality of single cells 22 are connected in parallel. Therefore, the current value flowing through each single cell 22 is equal to the current value flowing through each battery block 21 by the number of single cells 22 constituting the battery block 21. The current value is divided by (total). Specifically, when the total number of unit cells 22 constituting the battery block 21 is N and the current value flowing through the battery block 21 is Is, the current value flowing through each unit cell 22 is Is / N. . In this embodiment, it is assumed that internal resistance variation does not occur in the plurality of single cells 22 constituting the battery block 21.

  As the unit cell 22, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. An electric double layer capacitor (capacitor) can be used instead of the secondary battery. For example, as the single battery 22, a 18650 type battery can be used. The 18650 type battery is a so-called cylindrical battery, which has a diameter of 18 [mm] and a length of 65.0 [mm]. In a cylindrical battery, a battery case is formed in a cylindrical shape, and a power generation element for charging and discharging is accommodated in the battery case.

  As shown in FIG. 2, the unit cell 22 includes a power generation element 22a and a current breaker 22b. The power generation element 22 a and the current breaker 22 b are accommodated in a battery case that constitutes the exterior of the unit cell 22. The power generation element 22a is an element that performs charging and discharging. The constituent members of the power generation element in the unit cell 22 are the same as the constituent members of the power generation element in the unit cell 11.

  The current breaker 22b is used to cut off the current path inside the unit cell 22. That is, by operating the current breaker 22b, the current path inside the unit cell 22 is cut off. For example, a fuse, a PTC (Positive Temperature Coefficient) element, or a current cutoff valve can be used as the current breaker 22b. These current breakers 22b can be used individually or in combination.

  The fuse as the current breaker 22b is blown according to the current flowing through the fuse. By blowing the fuse, the current path inside the unit cell 22 can be mechanically interrupted. Thereby, it can prevent that an excessive electric current flows into the electric power generation element 22a, and can protect the cell 22 (electric power generation element 22a). The fuse as the current breaker 22b may be accommodated in the battery case, or may be disposed outside the battery case. Even when a fuse is disposed outside the battery case, the fuse is provided for each unit cell 22.

  The PTC element as the current breaker 22b is disposed in the current path of the unit cell 22, and increases the resistance in accordance with the temperature rise of the PTC element. When the current flowing through the PTC element increases, the temperature of the PTC element rises due to Joule heat. As the resistance of the PTC element increases as the temperature of the PTC element rises, current can be cut off in the PTC element. Thereby, it can prevent that an excessive electric current flows into the electric power generation element 22a, and can protect the cell 22 (electric power generation element 22a).

  The current cutoff valve as the current breaker 22b is deformed in response to an increase in the internal pressure of the unit cell 22, and can cut off the current path inside the unit cell 22 by breaking the mechanical connection with the power generation element 22a. it can. The inside of the unit cell 22 is in a sealed state, and when gas is generated from the power generation element 22a due to overcharging or the like, the internal pressure of the unit cell 22 increases. When gas is generated from the power generation element 22a, the unit cell 22 (power generation element 22a) is in an abnormal state. The mechanical connection with the power generation element 22a can be broken by deforming the current cutoff valve in response to the increase in the internal pressure of the unit cell 22. Thereby, it can block | prevent that charging / discharging electric current flows into the electric power generation element 22a in an abnormal state, and can protect the cell 22 (electric power generation element 22a).

  As shown in FIG. 1, the high-capacity assembled battery 20 is provided with a monitoring unit 23 that detects the voltage of each battery block 21 and outputs the detection result to the controller 35. Further, the current sensor 24 detects the value of the current flowing through the high capacity assembled battery 20 and outputs the detection result to the controller 35. The current sensor 24 only needs to be able to detect the value of the current flowing through the high-capacity assembled battery 20, and can be provided not on the positive electrode line PL2 but on the negative electrode line NL2. As with the high-power assembled battery 10, a positive value can be used for the discharge current value detected by the current sensor 24, and a negative value can be used for the charging current value.

  The controller 35 can incorporate a memory (storage unit) (not shown), and can store a program for operating the controller 35 and specific information in the storage unit. The memory can also be provided outside the controller 35.

  Next, a process for determining the operating state of the current breaker 22b in the battery system of the present embodiment will be described.

  The controller 35 of the present embodiment controls the drive of the inverter 31 and the motor / generator 32 described above, and includes a plurality of current breakers 22b connected in parallel to the high-capacity assembled battery 20 at a predetermined timing. The operating state determination process for determining the operating state of the current breaker 22b in the battery block 21 composed of the single cells 22 is performed.

  The predetermined timing includes when the battery system starts up after IG-ON and when it is externally charged. For example, the controller 35 is IG-ON to switch the system main relays SMR-B2 and SMR-G2 from off to on. (The system main relays SMR-B1 and SMR-G1 remain off) When the high-capacity assembled battery 20 is connected to the inverter 31 or at the start or end of external charging, the operating state determination process of the current breaker 22b Can be carried out.

  As described above, when the total number of the single cells 22 constituting the battery block 21 is N and the current value flowing through the battery block 21 is Is, the current value flowing through each single cell 22 is Is / N. When the current breaker 22b in the battery block 21 is operating, the current concentrates on the unit cell 22 where the current breaker 22b is not operating, and the flowing current value increases.

  Here, the current breaker 22b has a predetermined allowable current value to be activated, and cuts off the current path of the unit cell 22 when a current exceeding the allowable current value (corresponding to the reference current value) flows for a certain period of time. To work. The allowable current value of the current breaker 22b is defined from the viewpoint of suppressing the battery performance of the unit cell 22, for example, battery life, overcharge and early deterioration, and in the battery block 21 in which all the current breakers 22b are not operating. It is the upper limit of the charging / discharging current of the single cell 22 in which the current breaker operates with respect to the current flowing through each single cell 22.

  FIG. 3 is a diagram for explaining a method for determining the operating state of the current breaker 22b of the present embodiment. In the example of FIG. 3A, a plurality of battery blocks 21 in which six unit cells 22 are connected in parallel are connected in series.

  For example, when one single cell 22 is externally short-circuited, a “current wraparound” occurs in which more current out of the current flowing through the battery block 21 flows to the externally short-circuited cell 22, and The current breaker 22b is activated by the excessive current flowing.

  As shown in FIG. 3 (a), when one current breaker 22b of the plurality of current breakers 22b of the battery block 21B is activated, the other five single cells that are not activated. The current value that flows through these five unit cells 22 is increased due to the current being concentrated on 22. For example, when a current of 12A flows to the battery block 21, when the current breaker 22b is not activated, a current of 2A flows to each of the six unit cells 22, but one current breaker 22b is activated. In this state, a current of 2.4 A flows through each of the other five unit cells 22.

  The current 12A, which is the same as the battery block 21B, flows in the other battery blocks 21A, 21C in which no current breaker 22b is operating. At this time, a current of 2A flows in each unit cell 22. That is, in the plurality of battery blocks 21 connected in series through which the same current flows, when the current breaker 22b is operating in the battery block 21, no battery block 21 is operating. Rather, the value of the current flowing through each current breaker 22b increases.

  Therefore, in this embodiment, the allowable current value of the current breaker 22b is used, and the current is smaller than the allowable current value at which the current breaker 22b operates, and a predetermined number of current breakers 22b are activated in the battery block 21. As a result, the current flowing into the unit cell 22 in which the current breaker 22b is not operating rises above the allowable current value, and the current of a magnitude that activates all the non-operating current breakers 22b in the battery block 21 is supplied to the battery. By flowing to the block 21, the battery block 21 in which the current breaker 22b is in an operating state (in an operating state) is determined.

  As shown in FIG. 3B, for example, it is assumed that the allowable current value of the current breaker 22b is 3A. When the battery block 21 in which one current breaker 22b is operating is determined, if the current value flowing through the five unit cells 22 among the six unit cells 22 connected in parallel is 3A or more, each of the five unit cells Since the current breaker 22b in which the battery 22 is not operated operates, a current of 15 A flows to the high-capacity assembled battery 20.

  In the battery block 21B, the current flowing through each of the five single cells 22 is 3A, and a current larger than the allowable current value flows, so all the current breakers 22b are activated. On the other hand, although the current of 15A flows through the other battery blocks 21A and 21C, the current flowing through each unit cell 22 is 2.5A, and a current smaller than the allowable current value of the current breaker 22b flows. The current breakers 22b of the other battery blocks 21A and 21C do not operate.

  As described above, when a predetermined number of current breakers 22b are activated in the battery block 21, the current flowing through the remaining current breakers 22b is larger than the allowable current value, and no current breaker 22b is activated. A current that is smaller than the allowable current value flows through each of the current breakers 22b of the other battery blocks 21 through the battery blocks 21 connected in series, and a predetermined number of current breakers 22b are provided. By operating all the current circuit breakers 22b within the battery block 21 that is operating, the battery blocks 21 in a state where the current circuit breakers 22b are operating exist in the plurality of battery blocks 21 connected in series. Can be determined.

  Then, when a predetermined number of current breakers 22b are activated in the battery block 21, the current flowing through the remaining current breakers 22b is larger than the allowable current value, and no other current breaker 22b is activated. The voltage or current of the battery block 21 is monitored while a current that is smaller than the allowable current value flows in each current breaker 22b of the battery block 21. For example, the monitoring unit 23 When the voltage value of the battery block 22 cannot be detected (the output value cannot be acquired from the monitoring unit 23 or the detection error is acquired as the output value), or the detection value of the current sensor 24 becomes 0, the current breaker 22b The presence of the battery block 21 in an operating state, that is, the operating state of the current breaker 22b in the battery block 21 can be discriminated (obtained). That.

The value of the current that flows in the operation state determination process of the current breaker 22b of the present embodiment can be obtained as in the following equation (1).
(Expression 1) Current value I = (Number of parallels−Number of operations) × Allowable current value The number of parallels is the number of parallel connections of the cells 22 constituting the battery block 21. The operation number is a value indicating how many battery breakers 21 in which the current breaker 22b is operating, and the minimum value is 1.

  Since the number of parallel connections of the single cells 22 of the battery block 21 and the allowable current value of the current breaker 22b can be grasped in advance, how many battery block 21 the current breaker 22b is operating in other words, By setting the number of battery blocks 21 to be detected when more than one current breaker 22b is in an operating state, the current value I to be passed in the operating state determination process of the current breaker 22b can be determined in advance or as appropriate. it can. In the example of FIG. 3B, since the parallel number is 6 and the allowable current value is 3A, the current value I is 15A when determining the battery block 21 in which the number of operation of the current breaker 22b is 1.

  FIG. 4 is a flowchart showing an operation determination process of the current breaker 22b of the present embodiment.

  The controller 35 performs an operation determination process of the current breaker 22b in the high-capacity assembled battery 20 at the time of starting the battery system after IG-ON or external charging (S101). At this time, the system main relays SMR-B2, SMR-G2 are in the on state, the system main relays SMR-B1, SMR-G1 are in the off state, and the controller 35 confirms the on state and the off state of each system main relay. Perform switching control.

  The controller 35 causes the current value I calculated based on the above formula 1 to flow through the high-capacity assembled battery 20 (S102). As described above, the current value I detects the number of parallel connections of the single cells 22 of the battery block 21, the allowable current value of the current breaker 22b, and the battery block 21 when more than one current breaker 22b is in an operating state. It can be determined in advance or as appropriate based on the number of operations indicating whether or not to do so.

  The controller 35 controls the charging / discharging current corresponding to the current value I to flow through the high-capacity assembled battery 20 for a predetermined time. The predetermined time is based on the operating characteristics of the current breaker 22b that is defined in advance so as to operate when a current exceeding the allowable current value flows for a certain period of time.

  For example, after the IG-ON, the controller 35 drives the engine 34 to charge the electric power generated by the motor / generator 32 so that the charging current flows to the high-capacity assembled battery 20 or the power consumption of the vehicle. A device (for example, an air conditioner) can consume electric power, and a discharge current can be passed through the high-capacity assembled battery 20. In addition, when external charging is performed, external power supplied from an external power source can be charged to allow a charging current to flow through the high-capacity assembled battery 20.

  The controller 35 detects the high-capacity assembled battery 20 or each battery block 21 detected by the monitoring unit 23 while the charging / discharging current corresponding to the current value I flows through the high-capacity assembled battery 20 (battery block 21). A voltage value is acquired (S103). When there is no battery block 21 in which all the current breakers 22b in the battery block 21 are operated, any one of the battery blocks 21 connected in series is not an open circuit (open circuit), so the voltage of the battery block 21 You can get the value. On the other hand, when there is a battery block 21 in which all of the current breakers 22b in any of the battery blocks 21 connected in series exist, the battery block 21 is an open circuit, that is, the high-capacity assembled battery 20 Is disconnected, the voltage value of the battery block 21 cannot be acquired (S104).

  If the controller 35 cannot acquire the voltage value of the battery block 21 while the charging / discharging current corresponding to the current value I is flowing, the current breaker 22b in any one of the plurality of battery blocks 21 connected in series. Is determined to be in an activated state (S105). On the other hand, when the controller 35 can acquire the voltage value of the battery block 21 while the charge / discharge current corresponding to the current value I is flowing, the current breaker 22b is activated in all of the battery blocks 21 connected in series. It is determined that it has not been performed (S106).

  In steps S103 and S104, the operating state of the current breaker 22b can be determined using the output value of the current sensor 24 in addition to the voltage value of the battery block 21. For example, the controller 35 acquires an output value (detected value) detected by the current sensor 24 while charging / discharging current corresponding to the current value I is flowing through the high-capacity assembled battery 20, and the current in the battery block 21 is When there is a battery block 21 in which all the circuit breakers 22b are operated, the battery block 21 is an open circuit (open circuit), so the output value of the current sensor 24 is zero.

  On the other hand, when there is no battery block 21 in which all of the current breakers 22b in the battery block 21 are operated, the battery block 21 is not an open circuit, and therefore, a detected value of charge / discharge current according to the current value I (> 0) can be obtained from the current sensor 24. When the charge / discharge current corresponding to the current value I cannot be detected by the current sensor 24 (detection value = 0), the controller 35 activates the current breaker 22b in any one of the plurality of battery blocks 21 connected in series. It is determined that it is in the state (S105). Moreover, the controller 35 discriminate | determines that the current circuit breaker 22b is not act | operating in all the several battery blocks 21 connected in series, when the charge / discharge current according to the electric current value I can be detected by the current sensor 24 ( S106).

  If the controller 35 determines in step S105 that the current breaker 22b of the battery block 21 has been activated, all of the current breakers 22b in any of the battery blocks 21 in the high-capacity assembled battery 20 have been activated. Therefore, the high-capacity assembled battery 20 is controlled so as not to be charged and discharged by disconnecting the high-capacity assembled battery 20 from the battery system. EV traveling mode using the output type assembled battery 10) can be performed. At this time, the controller 35 can perform warning processing (lighting of the lamp, message display via the display unit, etc.) for notifying the user that an abnormality has occurred in the high-capacity assembled battery 20.

  As described above, in this embodiment, if the current breaker 22b is already operating in the battery block 21, the current is concentrated on the remaining single cells 22 where the current breaker 22b is not operating. If the current breaker 22b is activated but no current breaker 22b is activated, a current smaller than the allowable current value flows through the current breaker 22b and the current breaker 22b does not operate. Based on the detected value (output value) of the voltage or current of the battery block 21 detected during the flow, the battery block 21 in which the current breaker 22b is in an operating state among the plurality of battery blocks connected in series. Can be grasped accurately.

  In this embodiment, the remaining non-operating current circuit breakers 22b in the battery block 21 in which the predetermined number of current circuit breakers 22b have been operated are activated, and all the current circuit breakers 22b in the battery block 21 are activated. Since the operation state is set, the use of the high-capacity assembled battery 20 in a state where an abnormality has occurred can be appropriately stopped while accurately grasping the presence of the battery block 21 in which the current breaker 22b is in the operation state. .

  In this embodiment, a charging / discharging current corresponding to the current value I is supplied, and all the current breakers 22b of the battery block 21 in which at least one current breaker 22b is activated are connected in series. It can be accurately grasped that any one of the plurality of battery blocks 21 includes the battery block 21 in which the current breaker 22b is in an operating state. For example, the operating state of the current breaker 22b specifying each battery block 21 Can also be determined.

  For example, each voltage value can be acquired from the monitoring unit 23 for each battery block 21 by providing an equalization circuit including a resistance and a voltage detection resistor for each of the plurality of battery blocks 21. The controller 35 monitors the voltage value of each battery block 21 during the charging / discharging current corresponding to the current value I, that is, the output value from the monitoring unit 23, and detects one or more voltage values that cannot be detected. Each of the battery blocks 21 can be identified as the battery block 21 in which the current breaker 22b is operating.

  In the present embodiment, the voltage or current of the battery block 21 is monitored while the charging / discharging current corresponding to the current value I flows, but the present invention is not limited to this. For example, after a charging / discharging current corresponding to the current value I is supplied, a predetermined charging / discharging current is supplied separately to monitor the voltage or current of the battery block 21 to determine a battery block in which the current breaker 22b is in an operating state. be able to.

  FIG. 5 is a diagram for explaining a modification of the operating state determination of the current breaker 22b. As shown in FIG. 5, each battery block 21 can be provided with a current sensor 24 a that detects a current flowing through any one unit cell 22 in the battery block 21.

  For example, when the current breaker 22b connected to the unit cell 22 provided with the current sensor 24a is activated, the output value of the current sensor 24a becomes 0, and other than the unit cell 22 provided with the current sensor 24a is connected in parallel. When the current breaker 22b of the unit cell 22 is activated, as described above, the current value of the unit cell 22 provided with the current sensor 24a in which the current breaker 22b is not activated increases. The controller 35 can determine the operating state of the current breaker 22b in the battery block 21 for each battery block based on the output value of the current sensor 24a.

10: High-power assembled battery 11: Single battery 12: Monitoring unit 13: Current sensor 20: High-capacity assembled battery 21: Battery block 22: Single battery 22b: Current breaker 23: Monitoring unit 24: Current sensor 31: Inverter 32: Motor generator 33: Wheel 34: Engine 35: Controller

Claims (1)

Each having a plurality of power storage elements connected in parallel, a plurality of power storage blocks connected in series,
A controller for determining the state of each power storage block,
Each of the electricity storage elements has a current breaker that interrupts a current path inside the electricity storage element,
The controller is
The reference current value is a current that is smaller than a reference current value at which the current breaker is activated and flows into a storage element in which the current breaker is not activated due to activation of a predetermined number of current breakers in the storage block. The current breaker is activated based on the voltage or current detected value of the storage block. A power storage system characterized by determining a power storage block in a state.

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