JP5160024B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module, and in particular, a battery voltage detection line for detecting a voltage value of each unit cell of an assembled battery configured by connecting a plurality of unit cells whose resistances are connected in parallel via a switch. It is related with the battery module provided with the test | inspection means which test | inspects the connection state.

  For example, a battery module used for an electric vehicle or the like uses an assembled battery configured by connecting a plurality of single cells, and vibration during traveling is also applied, so it is important to ensure reliability. If any of the unit cells constituting the assembled battery has its function lowered due to overcharge, overdischarge, or the like, the function of the assembled battery as a whole is also lowered. For this reason, the battery module generally has a control circuit for monitoring the state of each unit cell. That is, the control circuit measures the voltage of each unit cell via the battery voltage detection line, and monitors the state of each unit cell including overcharge, overdischarge, and the like based on the measured voltage. For the inspection of the connection state of such battery voltage detection lines, conventionally, the battery voltage for each unit cell is measured (for example, see Patent Document 1), and the connection state is inspected by detecting the voltage of the unit cell. The method was general.

JP 2000-92732 A

  However, in the connection inspection of the conventional battery voltage detection line, only the open voltage of each unit cell is measured when the assembled battery is in a resting state. Therefore, it is measured when the battery voltage detection line is in a minute disconnection state. There is a problem that the battery voltage is not affected and the connection state of the battery voltage detection line is determined to be normal. In order to avoid such a misjudgment, some of the present inventors described in Japanese Patent Application No. 2002-338940 a voltage value and an open-circuit voltage value when a current is passed through a capacity adjustment resistor connected in parallel to a single cell. An application was made for an inspection circuit (inspection means) that determines whether there is an abnormality in the connection state of the battery voltage detection line by paying attention to the voltage difference. The present inventors have further studied the inspection circuit for the connection state (presence / absence of minute disconnection state) of the battery voltage detection line provided in the battery module, and have reached the improved invention of the above application.

  An object of the present invention is to provide a battery module including an inspection unit capable of accurately inspecting a connection state of a battery voltage detection line in view of the above case.

In order to solve the above-mentioned problem, the present invention provides a battery voltage for detecting a voltage value of each unit cell of an assembled battery configured by connecting a plurality of unit cells having resistors connected in parallel via a switch. In the battery module provided with the inspection means for inspecting the connection state of the detection lines, the inspection means includes the voltage value V1 of each unit cell constituting the assembled battery when all the switches are turned off, and the switch. Measure each voltage value V2 of all the unit cells constituting the assembled battery when every other unit cell is turned on, and for each of all the unit cells constituting the assembled battery, A voltage value V1 measured when the corresponding switch is in an OFF state and a voltage value V2 measured when the corresponding switch is in an OFF state or an ON state are compared, and a difference between the voltage values is set in advance. Checking the connection state of the battery voltage detection line corresponding to determine at either higher. In the case where the number of cells constituting the assembled battery is an even number, the inspection means sets the potential of the assembled battery that was not turned on when the voltage value of each cell was measured with every other switch turned on. Measure the voltage value V2 of the unit cell where the potential of the assembled battery is located at the end of the lowermost side with only the switch corresponding to the unit cell located at the end of the lowermost side turned on. the potential of said set battery voltage value V1 of the cells situated at the end of the least significant, measured as an off state, the end portion of the potential of said set battery was measured corresponding switch is turned on to the least significant The voltage value V2 of the unit cell located is compared, and it is determined whether or not the difference between the voltage values is equal to or greater than a specified value, and the potential of the assembled battery corresponds to the unit cell located at the end on the lowest side. What is necessary is just to test | inspect further the connection state of a battery voltage detection line .

In the present invention, the inspecting means sets all the switches to the off state, sets the voltage values V1 of all the unit cells constituting the assembled battery, and turns on every other switch corresponding to each unit cell. The voltage value V2 of each unit cell constituting the battery is measured, and for each unit cell constituting the assembled battery, the voltage value V1 measured when the corresponding switch is OFF and the corresponding switch The voltage value V2 measured in the off state or the on state is compared, and it is determined whether or not the difference between the voltage values is equal to or greater than a preset specified value. If there is, the voltage value when the resistor is connected in parallel with the cell and the current flows is different from that when the battery voltage detection line is normal (when there is no minute disconnection). Condition That there is an abnormality in it can be determined. Either the measurement in the off state or the measurement in the on state every other may be performed first. Moreover, it is preferable to use the capacity | capacitance adjustment resistance connected in parallel to each single cell for resistance. Furthermore, even if the number of cells constituting the assembled battery increases, the cell voltage in the on / off state of the switch is twice when the number of cells is an odd number and three times when the number of cells is an even number. Can be determined that there is an abnormality in the connection state of the battery voltage detection line.

According to the present invention, the inspection means sets all of the switches to the off state, sets the voltage values V1 of all the unit cells constituting the assembled battery, and turns on every other switch corresponding to each unit cell. each of the voltage value V2 of all the unit cells constituting the battery pack is measured, for each of all the unit cells constituting the battery pack, a voltage value V1 corresponding switch is measured in the off state, the corresponding By comparing with the voltage value V2 measured when the switch is in the off state or the on state, and determining whether or not the difference between the voltage values is greater than or equal to a preset specified value, a minute voltage is applied to the battery voltage detection line. If there is a disconnection, the voltage value when a resistor is connected in parallel with the unit cell and the current flows is different from that when the battery voltage detection line is normal, so the connection state of the battery voltage detection line is abnormal. about Can be determined, the effect can be obtained as.

(First embodiment)
Hereinafter, a first embodiment of an in-vehicle battery module to which the present invention can be applied will be described with reference to the drawings. In addition, this embodiment is an example in case the number of series cells of the cell which comprises an assembled battery is an odd number.

  As shown in FIG. 1, the battery module 19 of the present embodiment includes an assembled battery 18 in which five lithium ion secondary batteries (hereinafter referred to as single cells) 1, 4, 7, 10, 13 are connected in series. I have. The cells 1, 4, 7, 10, 13 are connected in series with resistors 2, 5, 8, 11, 14 connected in series and switches 3, 6, 9, 12, 15, which are composed of FETs, etc. It is connected. The resistors 2, 5, 8, 11, and 14 are capacities for adjusting the capacity of the corresponding single cells 1, 4, 7, 10, and 13, respectively. Each switch is a binary signal (Hi level signal (hereinafter abbreviated as Hi)), Lo level signal (hereinafter Lo) from an output port of a microcomputer (hereinafter referred to as a microcomputer) 17 as a part of detection means. ON / OFF control is possible by the output of)).

  The voltage of each unit cell is input to the voltage measurement circuit 16 via voltage detection lines L1, L2, L3, L4, L5, and L6 as battery voltage detection lines. The voltage measurement circuit 16 can be constituted by a multiplexer or the like, for example, and the analog voltage of the designated measurement target cell is designated by the voltage detection line L6 according to the designation of the measurement target cell from the battery designation port of the microcomputer 17. It converts into a reference | standard and outputs to AD input port of the microcomputer 17.

  The microcomputer 17 is a CPU that performs arithmetic processing, a ROM that stores programs executed by the CPU and program data such as various setting values, a RAM that functions as a work area of the CPU, and an analog voltage from the voltage measurement circuit 16 as a digital voltage. An A / D converter for conversion is included. In addition to the above-described ports, the microcomputer 17 has a port (not shown) for communicating with a host system that controls the battery module 19 via an interface (I / F). ing.

  Next, with reference to a flowchart, operation | movement of the battery module 19 of this embodiment is demonstrated. When the microcomputer 17 is turned on, a program or the like stored in the ROM is expanded in the RAM, and an inspection routine for inspecting the connection state of the voltage detection lines L1 to L6 (the presence or absence of minute disconnection) can be executed. When a predetermined signal is received from the host system, the inspection routine shown in FIG. 2 is executed by the CPU of the microcomputer 17.

  In this inspection routine, first, all the output signals of the output ports are set to Lo, and the switches 3, 6, 9, 12, and 15 are turned off (step 101). Next, the measurement target cell is designated as the cell 1 in the voltage measurement circuit 16 (step 102), and the voltage value Va1 of the cell 1 is measured via the voltage measurement circuit 16 (digital from the A / D converter). The voltage value is taken in and stored (stored in the RAM) (step 103). Next, the unit cell to be measured is designated as the unit cell 4 in the voltage measurement circuit 16 (step 104), and the voltage value Vb1 of the unit cell 4 is measured and stored through the voltage measurement circuit 16 (step 105). Subsequently, the voltage values of the remaining batteries 7, 10 and 13 are similarly measured, and the voltage values Vc1, Vd1 and Ve1 when the switches are in the off state are measured and stored (steps 106 to 111).

  Next, in order to turn on every other switch 3, 6, 9, 12, and 15, the output signal of the output port is set to HiLoHiLoHi, and the switches 3, 9, and 15 are turned on (step 201). Next, the unit cell to be measured is designated as the unit cell 1 in the voltage measurement circuit 16 (step 202), and the voltage value Va2 of the unit cell 1 is measured and stored through the voltage measurement circuit 16 (step 203). Subsequently, the voltage values of the remaining batteries 4, 7, 10, and 13 are similarly measured, and the voltage values Vb2, Vc2, Vd2, and Ve2 when the switches are turned on are measured and stored (steps 204 to 211). .

  Next, the voltage value Va1 when the switch 3 is turned off is compared with the voltage value Va2 when the switch 3 is turned on, and it is determined whether or not the difference between the two is a specified value (for example, 0.8 V) or more. (Step 301) Thus, when the determination is affirmative, it is determined that the voltage detection line L1 or L2 is abnormal. When the determination is negative, it is determined that both the voltage detection lines L1 and L2 are normal. In the flowchart of FIG. 2 and the like, the determination result is also described so that such processing can be clearly understood. Similarly, the voltage value Vb1 and the voltage value Vb2 are compared to determine whether the voltage detection line L2 and the voltage detection line L3 are abnormal. The voltage value Vc1 and the voltage value Vc2 are compared to compare the voltage detection line L3 and the voltage value Vb2. By comparing the voltage value Vd1 and the voltage value Vd2 for the presence / absence of the abnormality in the detection line L4, by comparing the voltage value Ve1 and the voltage value Ve2 for the presence / absence of the abnormality in the voltage detection line L4 and the voltage detection line L5. The presence or absence of abnormality in voltage detection line L5 and voltage detection line L6 is determined (steps 302 to 305), and the inspection routine is terminated.

  Therefore, the CPU of the microcomputer 17 can determine which voltage detection line is normal or abnormal from all the determination results, and informs the host system when any one of the voltage detection lines L1 to L6 is abnormal (see FIG. In step 2, these steps are discarded.) For example, the host system notifies the driver that there is an abnormality in the battery module 19 by displaying that fact on the installation panel. In this case, the host system may display on the installation panel that the specific voltage detection line is abnormal, or may notify the dedicated jig of the voltage detection line.

(Second Embodiment)
Next, a second embodiment of the in-vehicle battery module to which the present invention can be applied will be described. The present embodiment is an example in the case where the number of series cells constituting the assembled battery is an even number. In the present embodiment, the same circuit elements (configurations) as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different portions will be described.

  As shown in FIG. 3, the battery module 20 of the present embodiment includes a single cell 21 compared to the battery module 19 of the first embodiment in which five single cells 1, 4, 7, 10, and 13 are connected in series. Further, six assembled batteries 24 connected in series are provided. The unit cell 21 is connected in parallel with a resistor 23 and a switch 23 composed of an FET or the like connected in series. Similarly to the other switches, the switch 23 outputs a binary signal from the output port of the microcomputer 17. ON / OFF control is possible by this. Similarly to the other single cells, the voltage of the single cell 21 is input to the voltage measurement circuit 16 via the voltage detection lines L6 and L7, and the voltage measurement circuit 16 receives the single measurement target from the single cell designation port of the microcomputer 17. According to the designation of the battery, the analog voltage of the designated measurement target cell is converted with reference to the voltage detection line L7 and output to the AD input port of the microcomputer 17.

  Next, with reference to a flowchart, operation | movement of the battery module 20 of this embodiment is demonstrated. Note that the CPU of the microcomputer 17 executes the inspection routine shown in FIG. 4 when receiving a predetermined signal from the host system.

  In this inspection routine, first, all the output signals of the output ports are set to Lo, and the switches 3, 6, 9, 12, 15, and 23 are turned off (step 401). Next, the unit cell to be measured is designated as the unit cell 1 in the voltage measurement circuit 16 (step 402), and the voltage value Va1 of the unit cell 1 is measured and stored through the voltage measurement circuit 16 (step 403). Next, the unit cell to be measured is designated as the unit cell 4 in the voltage measurement circuit 16 (step 404), and the voltage value Vb1 of the unit cell 4 is measured and stored through the voltage measurement circuit 16 (step 405). Subsequently, the remaining batteries 7, 10, 13, and 21 are similarly measured for voltage values, and the voltage values Vc 1, Vd 1, Ve 1, and Vf 1 when the switch is off are measured and stored (steps 406 to 413). .

  Next, in order to turn on every other switch, the output signal of the output port is set to HiLoHiLoHiLo, and the switches 3, 9, and 15 are turned on (step 501). Next, the unit cell to be measured is designated as the unit cell 1 in the voltage measurement circuit 16 (step 502), and the voltage value Va2 of the unit cell 1 is measured and stored through the voltage measurement circuit 16 (step 503). Subsequently, the voltage values of the remaining batteries 4, 7, 10, and 13 are similarly measured, and the voltage values Vb2, Vc2, Vd2, and Ve2 when the switches are on are measured and stored (steps 504 to 511). . Furthermore, when the switch is turned on every other switch, the output port signal is set to LoLoLoLoLoHi to turn on only the switch 23 corresponding to the lowest cell 21 that was not turned on. The voltage measurement circuit 16 designates the unit cell to be measured as the unit cell 21 (step 602), and measures and stores the voltage value Vf2 of the unit cell 21 via the voltage measurement circuit 16 (step 601). 603).

  Next, the voltage detection line L1 or L2 is abnormal by determining whether or not the difference between the voltage value Va1 when the switch 3 is turned off and the voltage value Va2 when the switch 3 is turned on is greater than or equal to a specified value. (In the case of affirmative determination), it is determined whether both of the voltage detection lines L1 and L2 are normal (in the case of negative determination) (step 701). Similarly, the voltage value Vb1 and the voltage value Vb2 are compared to determine whether the voltage detection line L2 and the voltage detection line L3 are abnormal. The voltage value Vc1 and the voltage value Vc2 are compared to compare the voltage detection line L3 and the voltage detection line. Comparing the voltage value Vd1 and the voltage value Vd2 for the presence / absence of abnormality of L4, the presence / absence of the abnormality of the voltage detection line L4 and the voltage detection line L5, comparing the voltage value Ve1 and the voltage value Ve2 to the voltage detection line L5 Whether the voltage detection line L6 is abnormal is determined by comparing the voltage value Vf1 with the voltage value Vf2 to determine whether the voltage detection line L6 is abnormal (steps 702 to 706). Therefore, the CPU of the microcomputer 17 can determine which voltage detection line is normal or abnormal from all the determination results.

(Third embodiment)
Next, a third embodiment of an in-vehicle battery module to which the present invention can be applied will be described. The circuit elements of the present embodiment are the same as those of the second embodiment, and the inspection routine executed by the CPU of the microcomputer 17 is different. For this reason, in this embodiment, description of a circuit element is abbreviate | omitted and it demonstrates focusing on a different operation | movement location.

As shown in FIG. 5, the inspection routine executed by the CPU of the microcomputer 17 of this embodiment is the same as that of the second embodiment in steps 401 to 413. Next, the CPU of the microcomputer 17 designates the assembled battery 24 in the voltage measuring circuit 16 (step 414), and measures and stores the voltage value Vg1 of the assembled battery 24 via the voltage measuring circuit 16 (step 415). The next steps 501 to 511 are the same as those in the second embodiment. Then, electrodeposition in pressure measurement circuit 16 the measured unit cell designated as a single battery 21 (step 802), and stores the measured voltage value Vf2 of the voltage measuring circuit 16 through the unit cell 21 (step 803). Subsequently, all the output signals of the output ports are set to Hi, and all the switches are turned on (step 801). Next, the assembled battery 24 is designated to the voltage measuring circuit 16 (step 804), and the voltage value Vg2 of the assembled battery 24 is measured and stored via the voltage measuring circuit 16 (step 805). Subsequently, as in the second embodiment, after determining whether or not there is an abnormality in the voltage detection lines L1 to L6 (steps 701 to 705), the voltage value Vf1 and the voltage value Vf2 are compared, and the difference between the two is equal to or greater than a specified value. By determining whether or not there is an abnormality in the voltage detection line L6 (step 707), the voltage value Vg1 and the voltage value Vg2 are compared, and it is determined whether or not the difference between the two is equal to or greater than a specified value. Whether or not the voltage detection line L7 is abnormal is determined (step 708). Therefore, the CPU of the microcomputer 17 can determine which voltage detection line is normal or abnormal from all the determination results.

  As described above, in the battery modules 19 and 20 of the above-described embodiment, when the voltage detection line is in an abnormal state, for example, when there is a minute disconnection, the voltage value when a current is flowed by connecting a resistor in parallel with the unit cell, The difference between the open voltage value of the unit cell (the voltage value measured when the switch is off) exceeds the predetermined value, and the connection state of the voltage detection line is abnormal. Even if the number of cells constituting the battery pack increases, the switch is switched twice if the number of cells in series is odd or three if the number of cells is even. By measuring the cell voltage in the on / off state, it can be determined that there is an abnormality in the connection state of the voltage detection line. Therefore, according to the battery modules 19 and 20 of the above embodiment, the connection state of the voltage detection line can be accurately inspected.

  In the above embodiment, the microcomputer 17 has an A / D converter. However, the voltage measurement circuit 16 converts the analog voltage value into the digital voltage value and outputs the converted voltage to the microcomputer 17. Good. Moreover, in the said embodiment, although assembled battery (18, 24) was illustrated, this invention is not limited to this, It is applicable also to the cell group comprised by odd number or even number. Therefore, the term “assembled battery” of the present invention includes a single battery group. Furthermore, in the above embodiment, 5 series to 6 series unit cells are illustrated, but a mode in which a plurality of unit cell groups in which a plurality of unit cells are connected in parallel may be adopted.

  Since the present invention provides a battery module provided with an inspection means capable of accurately inspecting the connection state of the battery voltage detection line, it contributes to the manufacture and sale of the battery module, and thus has industrial applicability.

1 is a block circuit diagram of a battery module according to a first embodiment to which the present invention is applicable. It is a flowchart of the test | inspection routine which CPU of the microcomputer of the battery module of 1st Embodiment performs. It is a block circuit diagram of the battery module of 2nd, 3rd embodiment which can apply this invention. It is a flowchart of the test | inspection routine which CPU of the microcomputer of the battery module of 2nd Embodiment performs. It is a flowchart of the test | inspection routine which CPU of the microcomputer of the battery module of 3rd Embodiment performs.

Explanation of symbols

1, 4, 7, 10, 13, 21 Cell 2, 5, 8, 11, 14, 22 Resistor 3, 6, 9, 12, 15, 23 Switch 16 Voltage measurement circuit (part of inspection means)
17 Microcomputer (part of inspection method)
18, 24 Battery pack 19, 20 Battery module L1, L2, L3, L4, L5, L6, L7 Voltage detection line (battery voltage detection line)

Claims (2)

  Inspecting means for inspecting the connection state of the battery voltage detection line for detecting the voltage value of each unit cell of the assembled battery configured by connecting a plurality of unit cells connected in parallel via a switch. In the battery module, the inspection means includes a voltage value V1 of each unit cell constituting the assembled battery when all the switches are turned off, and one switch corresponding to each unit cell. The voltage value V2 of each of all the cells constituting the assembled battery when every other battery is turned on is measured, and the corresponding switch is turned off for each of all the cells constituting the assembled battery. The voltage value V1 measured at the time is compared with the voltage value V2 measured when the corresponding switch is in the off state or the on state, and the difference between the voltage values is equal to or larger than a preset specified value. Battery module, characterized by checking the connection state of the battery voltage detection line corresponding to determine whether. If serial number of the unit cells constituting the battery pack is even, the inspection unit, the sets that did not turned on when measuring the voltage value of each cell wherein every other switch is turned on to the assembled potential of the battery measures the voltage value V2 of the cells situated at the end of the least significant only switches the potential of the battery corresponds to the unit cell located at the end of the lowermost side as the oN state, the potential of the battery pack of the measurement of all the switches is turned off is a voltage value V1 of the cells situated at the end of the lowermost side, the potential of the battery pack of the measurement of the corresponding switch is turned on to the least significant compares the voltage value of the cell located at the end V2 of, at an end potential of the lowest side of the battery pack difference between the voltage value to determine whether or not the specified value or higher connection state of the battery voltage detection line corresponding to the unit cells of The battery module according to claim 1, characterized in that the further checking.

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