JP6274020B2 - Voltage detection unit - Google Patents

Description

  The present invention relates to a voltage detection unit of a power storage device including a plurality of power storage elements.

  An assembled battery in which a plurality of batteries are connected in series is provided with a voltage detection circuit (voltage sensor) that detects the total voltage of the entire assembled battery and the voltage of each battery (for example, Patent Document 1).

JP 2014-018065 A

  The voltage detection circuit is connected to a plurality of voltage detection lines extending from each battery constituting the assembled battery, but when a short circuit occurs between adjacent voltage detection lines due to water entering or the like, a closed circuit is formed in the voltage detection circuit. And the energized state may be continued.

  At this time, in order to protect the voltage detection circuit, a fuse can be provided in the voltage detection line or the voltage detection circuit, and the fuse can be blown by a current flowing through the closed circuit. However, as in Patent Document 1, if the voltage applied to the adjacent voltage detection lines is a voltage for one battery, the current flowing through the closed circuit is small, and the fuse cannot be blown, and the current-carrying state due to a short circuit May continue.

  Therefore, the present invention provides a voltage detection unit that detects each voltage value of a plurality of power storage elements, and can suppress continuation of an energized state even if a short circuit occurs between adjacent voltage detection lines. For the purpose.

  The present invention is a voltage detection unit that detects a voltage value of each power storage element of a power storage device in which a plurality of power storage elements are connected in series. The voltage detection unit detects a voltage value of each storage element via a plurality of voltage detection lines connected to each storage element and a pair of voltage detection lines connected to the positive terminal and the negative terminal of the storage element. A circuit and a plurality of voltage detection lines are arranged adjacent to each other in a predetermined direction, a connector for connecting the plurality of voltage detection lines to the voltage detection circuit, and each current when a current exceeding the allowable current value flows. And a protection element that cuts off an electrical connection between the power storage element and the voltage detection circuit via the detection line.

  At this time, the connector is configured such that each voltage detection line that is a combination of potential differences corresponding to block voltages of a plurality of power storage elements connected in series is arranged adjacent to each other in a predetermined direction. ing.

  According to the present invention, in the voltage detection unit that detects the voltage value of each power storage element via the corresponding pair of voltage detection lines, the connector is connected to the block voltage of a plurality of power storage elements connected in series. Each voltage detection line that is a combination of corresponding potential differences is arranged adjacent to each other in a predetermined direction. For this reason, the voltage applied when the voltage detection lines are short-circuited is not a voltage for one power storage element, but a block voltage in which a plurality of power storage elements of a predetermined number or more are connected in series. The applied voltage is increased, and a current exceeding the allowable current value flows, so that the protection element is easily operated. Therefore, when the adjacent voltage detection lines are short-circuited, the protection element can be operated smoothly, and the continuity of the energized state can be suppressed.

It is a figure which shows the structure of the battery system mounted in the vehicle of Example 1. FIG. 3 is a diagram illustrating a configuration of a voltage detection unit connected to the assembled battery of Example 1. FIG.

  Examples of the present invention will be described below.

Example 1
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 an assembled battery 10 (corresponding to a power storage device). The assembled battery 10 includes a plurality of single cells 11 (corresponding to power storage elements) that are electrically 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. The number of the single cells 11 constituting the assembled battery 10 can be set as appropriate.

  The assembled battery 10 is connected to the inverter 31 via the positive electrode line PL and the negative electrode line NL. System main relays SMR-B and SMR-G are provided on the positive line PL and the negative line NL, respectively. The system main relays SMR-B and SMR-G are controlled to be turned on / off by a controller 50, which will be described later, and the connected state (Ready-ON) and disconnected state (Ready-OFF) between the assembled battery 10 and the inverter 31 (load). And is allowed. For example, the controller 50 turns on and off the system main relays SMR-B and SMR-G in response to input of information related to on / off (IG-ON, IG-OFF) of the ignition switch of the vehicle. Switch with.

  The inverter 31 (load) converts the DC power supplied from the assembled battery 10 into AC power. A motor / generator 32 (AC motor) is connected to the inverter 31. 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. When the vehicle is a hybrid vehicle, an engine (not shown) is connected to the wheel 33, and kinetic energy generated by the engine is transmitted to the wheel 33. Thereby, a vehicle can be drive | worked using the output of the assembled battery 10 or an engine. Note that a booster circuit may be arranged in the current path between the assembled battery 10 and the inverter 31.

  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 the AC power generated by the motor / generator 32 into DC power and supplies the DC power to the assembled battery 10. Thereby, the assembled battery 10 can store regenerative electric power. In the case of a hybrid vehicle, in addition to regenerative power, the motor / generator 32 can be driven by the engine to store electric energy in the assembled battery 10.

  The controller 50 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. The controller 50 can include a memory (not shown) that stores various types of information. The memory can be provided so as to be built in or externally attached to the controller 50.

  The controller 50 can also be provided for each inverter 31 and motor / generator 32. The controller 50 can be configured as a control device that controls the entire vehicle, or can be configured as a battery control device that is individually configured with respect to a separate control device that controls the entire vehicle.

  The monitoring unit 40 includes a voltage detection circuit 41 to be described later, detects the voltage value between terminals of the battery pack 10 (total voltage value), detects each voltage value of the plurality of single cells 11, and the detection result Is output to the controller 50.

  In the battery system shown in FIG. 1, a current sensor and a temperature sensor can be provided (not shown). A current sensor provided on the current path of the assembled battery 10 can detect a charge / discharge current flowing in the assembled battery 10 and output the detection result to the controller 50. Further, the temperature sensor provided in the assembled battery 10 can detect the battery temperature of the assembled battery 10 and output the detection result to the controller 50.

  The controller 50 can calculate the state of charge (SOC) of the assembled battery 10 based on the detection value, current value, and the like of the monitoring unit 40, and can grasp the input / output power of the assembled battery 10. Charge / discharge control according to the output request can be performed.

  Next, the voltage detection unit of this embodiment will be described with reference to FIG. As shown in FIG. 2, a plurality of voltage detection lines L <b> 1 to L <b> 8 are connected to each of the plurality of single cells 11. The voltage detection lines L1 to L8 extending from the unit cell 11 are connected to the voltage detection circuit 41, respectively. The voltage detection circuit 41 detects the voltage between the voltage detection lines and outputs the detection result to the controller 50.

  For example, the voltage detection line L1 is connected to the positive terminal of the cell 11a, and the voltage detection line L2 is connected to the negative terminal of the cell 11a. By measuring the potential difference between the pair of voltage detection lines L1 and L2, the voltage of one unit cell 11a can be detected. That is, the voltage of one unit cell 11a is applied between the pair of voltage detection lines L1 and L2.

  Between the other pair of voltage detection lines L2 and L3, between voltage detection lines L3 and L4, between voltage detection lines L4 and L5, between voltage detection lines L5 and L6, between voltage detection lines L6 and L7, and voltage detection lines L7 and L8 In addition, the potential difference between the single cells 11 connected in series becomes a potential difference, and one single cell is detected in each of the plurality of single cells 11 connected in series by detecting the voltage between the voltage detection lines. The voltage can be individually detected every 11.

  Since the voltage detection lines L1 and L8 have a potential difference corresponding to the inter-terminal voltage (total voltage) of the battery pack 10 composed of the plurality of single cells 11 connected in series, the voltage detection lines L1 and L8. By detecting the potential difference between them, the voltage between the terminals of the assembled battery 10 can be detected.

  Moreover, each voltage detection line L2-L7 is connected to the negative electrode terminal of one unit cell 11, and the positive electrode terminal of the other unit cell 11 in the two unit cells 11 electrically connected in series. . In addition, although the voltage detection line is used in common by two adjacent unit cells 11 connected in series, the present invention is not limited to this, and each unit cell 11 is configured to have an individual voltage detection line. May be.

  Connection of the assembled battery 10 (unit cell 11) and the voltage detection circuit 41 via the voltage detection lines L1 to L8 can be performed via a connector, for example. As shown in FIG. 2, the plurality of voltage detection lines L1 to L8 extending from the unit cell 11 are connected to the connector C1 on the assembled battery 10 side. The voltage detection lines L1 to L8 extending from the voltage detection circuit 41 are connected to the connector C2 on the monitoring unit 40 side.

  By connecting the connector C1 and the connector C2 to each other, the plurality of single cells 11 and the voltage detection circuit 41 are connected via one voltage detection line L1 to L8. The connectors C1 and C2 are, for example, male / female connection adapters that fit together.

  Resistive elements R are provided between the connector C2 and the voltage detection circuit 41, in other words, on the voltage detection lines L1 to L8 between the assembled battery 10 and the voltage detection circuit 41, respectively. The resistance element R (corresponding to a protection element) functions as a fuse, and melts and cuts off the energization path when a current exceeding a preset allowable current value flows through the voltage detection line.

For example, in the region S shown in FIG. 2, when the adjacent voltage detection lines are short-circuited due to water or the like, a current corresponding to the applied voltage between the voltage detection lines flows, and the resistance is detected when the current value is equal to or greater than the allowable current value. The element R is blown out.

  As shown in FIG. 2, the resistance element R is individually provided for the voltage detection circuit 41 or configured to be included in the voltage detection circuit 41 as a part of the circuit configuration of the voltage detection circuit 41. can do.

  The plurality of voltage detection lines L1 to L8 connected to the connector C1 on the assembled battery 10 side can be arranged side by side in the longitudinal direction of the connector C1, for example. As in the example of FIG. 2, in the connector C <b> 1, the plurality of voltage detection lines L <b> 1 to L <b> 8 are arranged adjacent to each other in the vertical direction of the paper. Similarly, in the connector C2, the voltage detection lines L1 to L8 extending from the voltage detection circuit 41 are arranged adjacent to each other in the vertical direction on the paper surface in the connector C2.

  The voltage detection circuit 41 includes connection terminals 41A to 41H as connection ports of the voltage detection lines L1 to L8 extending from the connector C2, and the connection terminals 41A to 41H are adjacent to each other in the vertical direction on the paper surface. Arranged together.

  As described above, the plurality of voltage detection lines L1 to L8 connecting the assembled battery 10 and the voltage detection circuit 41 are arranged adjacent to each other in the vertical direction on the paper surface according to the connector C2 or the connection terminals 41A to 41H.

  Here, when a pair of voltage detection lines for detecting the voltage of one unit cell 11 are connected adjacent to each other at the connector C2 or the connection terminals 41A to 41H, the voltage of one unit cell 11 is detected as described above. When a pair of voltage detection lines are short-circuited, a current corresponding to the applied voltage between the voltage detection lines flows in the closed circuit due to the short circuit, and the applied voltage at that time is a voltage corresponding to one unit cell 11.

  However, the voltage for the voltage of one unit cell 11 is low, and there is a possibility that a current exceeding the allowable current value at which the resistance element R is fused does not flow. In this case, since the resistance element R does not function as a protection element, the energized state is maintained due to a short circuit, and the voltage detection circuit 41 cannot be appropriately protected due to heat generated by energization.

  Therefore, the connector of the present embodiment is connected so that a pair of voltage detection lines corresponding to one unit cell 11 are not adjacent to each other in the voltage detection lines arranged adjacent to each other, and is connected in series. The voltage detection lines are arranged adjacent to each other in the direction in which the voltage detection lines are arranged so as to be a combination of potential differences corresponding to block voltages of a plurality of unit cells 11.

  Specifically, as shown in FIG. 2, a pair of voltage detection lines L <b> 1 to L <b> 8 for detecting the voltage of one unit cell 11 in a plurality of unit cells 11 connected in series intersect each other with respect to the connector C <b> 1. The voltage detection lines L1 to L8 are connected so that a voltage difference corresponding to the block voltage of the plurality of single cells 11 between the adjacent voltage detection lines at the connector C2 and the connection terminals 41A to 41H is equal to or greater than a predetermined number. Change the adjacent array.

  In the example of FIG. 2, the voltage detection line L1 is first connected to the connector C1 in the direction in which the voltage detection lines are arranged, and the voltage detection line L5 is connected next to the connector C1 instead of the voltage detection line L2. Next, the voltage detection line L2 is connected next to the voltage detection line L5. In the same manner, voltage detection lines L6, L3, L7, L4, and L8 are connected in this order.

  In the connector C2, the voltage detection lines are arranged adjacent to each other in the order of the voltage detection lines L1, L5, L2, L6, L3, L7, L4, and L8 in the direction in which the voltage detection lines are arranged. , L5, L2, L6, L3, L7, L4, and L8, the voltage detection lines are connected to the connection terminals 41A to 41H of the voltage detection circuit 41, respectively.

  Therefore, in the circuit configuration of the voltage detection circuit 41 for detecting the voltage between the voltage detection lines, the pair of voltage detection lines for detecting the voltage of one unit cell 11 is connected to the voltage detection circuit 41 so as not to be adjacent to each other, The potential difference between the voltage detection lines L1 and L5 connected to the adjacent connection terminals 41A and 41B becomes the block voltage of the four unit cells 11 connected in series, and the voltage detection connected to the adjacent connection terminals 41B and 41C. The potential difference between the lines L5 and L2 becomes the block voltage of the three unit cells 11 connected in series.

  With this configuration, when a short circuit occurs between adjacent voltage detection lines, the voltage applied to the closed circuit due to the short circuit becomes a block voltage of a predetermined number or more of the cells 11 connected in series. A voltage higher than the voltage of one unit cell 11 is applied. The voltage applied at the time of a short circuit becomes high, the electric current more than an allowable electric current value flows, and it becomes easy for the resistive element R to blow out. When the adjacent voltage detection lines are short-circuited, the resistance element R can be smoothly blown, and the continuity of the energized state can be suppressed.

  Next, the voltage detection method by the voltage detection unit of a present Example is demonstrated. As described above, the pair of voltage detection lines for detecting the voltage of one single battery 11 is not connected adjacent to each other at the connection terminals 41A to 41H. For this reason, as shown in FIG. 2, in the connection terminals 41 </ b> A to 41 </ b> H, the potential difference between the connection terminals corresponding to the pair of voltage detection lines for detecting the voltage of one unit cell 11, not between the adjacent connection terminals, respectively. Configured to detect.

  A potential difference between the connection terminal 41A to which the voltage detection line L1 is connected and the connection terminal 41C to which the voltage detection line L2 that is not adjacent in the order in which the connection terminals 41A to 41H are arranged is detected, and the voltage V1 of the unit cell 11a is detected. Can be detected. Similarly, as shown in FIG. 2, the voltages V <b> 2 to V <b> 7 of each unit cell 11 can be selectively detected by detecting a potential difference between connection terminals that are not adjacent to each other. The voltage V0 is a voltage between terminals of the assembled battery 10 corresponding to a potential difference between the voltage detection lines L1 and L8.

  Note that the connector C1 and the connector C2 have been described as an example of connectors for connecting the plurality of voltage detection lines L1 to L8 to the voltage detection circuit 41. For example, the connector C1 and the voltage detection circuit are not connected via the connector C2. 41 can also be directly connected via the voltage detection lines L1 to L8, and the connector C2 can be omitted. Even in this case, in the connector C1, the voltage detection lines L1 to L8 extending from the assembled battery 10 are not connected adjacent to each other between the pair of voltage detection lines corresponding to one unit cell 11. Between the adjacent voltage detection lines connected to the connection terminals 41A to 41H from the connector C1 is a combination of voltage differences corresponding to the block voltages of a plurality of unit cells 11 connected in series. Thus, it can be configured to be connected to the voltage detection circuit 41. The same applies to the case where the connector C1 is omitted and the voltage detection lines L1 to L8 extending from the assembled battery 10 are connected to the connector C2 in the same manner as the connector C1.

  In the example of FIG. 2, in the connector C1 and the connector C2, a plurality of voltage detection lines are arranged in the vertical direction on the paper surface. For example, a plurality of voltage detection lines aligned in the vertical direction on the paper surface are arranged. Further, it can be arranged in a plurality of rows in the thickness direction of the connector orthogonal to the vertical direction of the paper surface. In this case, the voltage applied to the closed circuit due to the short circuit is connected in series when the same configuration as described above is applied between the voltage detection lines adjacent in the column direction and the adjacent voltage detection lines are short-circuited. In addition, the block voltage of the unit cells 11 of a predetermined number or more can be configured.

10: assembled battery 11: single battery (storage element)
31: Inverter 32: Motor generator 33: Wheel 40: Monitoring unit 41: Voltage detection circuits 41A to 41H: Connection terminal 50: Controller C1, C2: Connector R: Resistance element (protection element)
PL: positive electrode line NL: negative electrode line L1-L8: voltage detection line

Claims (1)

A voltage detection unit that detects a voltage value of each of the power storage elements of a power storage device in which a plurality of power storage elements are connected in series,
A plurality of voltage detection lines connected to each of the storage elements;
A voltage detection circuit that detects a voltage value of each storage element via a pair of voltage detection lines connected to a positive electrode terminal and a negative electrode terminal of the storage element;
A plurality of the voltage detection lines arranged adjacent to each other in a predetermined direction, and a connector for connecting the plurality of voltage detection lines to the voltage detection circuit;
A protection element that cuts off an electrical connection between the power storage element and the voltage detection circuit via each voltage detection line when a current greater than an allowable current value flows;
In the connector, each voltage detection line that is a combination of potential differences corresponding to block voltages of a plurality of the power storage elements of a predetermined number or more connected in series is arranged adjacent to each other in the predetermined direction. Characteristic voltage detection unit.

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