JP2016220300A - Battery monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high-precision voltage detection for each battery cell in a voltage monitoring device supplied with operating power from a battery block including battery cells connected in series.SOLUTION: In a battery monitoring device 500 including a monitoring IC 100 which is supplied with operating power from a battery block 10 including battery cells 21 to 24 connected in series to monitor the voltages of the battery cells 21 to 24, and positive and negative power supply connectors 32, 42 which are respectively provided to positive electrode and negative electrode cableways 31, 41 which are connected to a positive electrode terminal 11 and a negative electrode terminal 13 of the battery block 10 to supply operation power to the monitoring IC 100, the monitoring IC 100 includes a voltage drop detector 200 for detecting the voltage drop of the positive electrode or negative electrode power supply connector 32, 42 when operating current flows through the positive electrode and negative electrode cableways 31, 41, and a controller 300 for determining increase of the resistance of the positive electrode or negative electrode power supply connector 32, 42 on the basis of the voltage value detected by the voltage drop detector 200.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a structure of a battery monitoring device that monitors the voltage of each battery cell of a battery block in which a plurality of battery cells are connected in series.

  In recent years, electric vehicles that use a motor generator to drive a vehicle have been increasingly used. Such an electric vehicle is equipped with a battery that supplies electric power to the motor generator or charges electric power generated by the motor generator. As the battery, a battery that outputs a high voltage by connecting a large number of battery cells of a secondary battery such as a nickel metal hydride battery or a lithium battery in series is often used. Many high voltage batteries in recent years are configured by connecting about 50 to 100 battery cells in series.

  In the high-voltage battery having such a configuration, the voltage at both ends of each battery cell, that is, the state of charge (SOC) varies as charging and discharging are repeated. When charging or discharging a battery, from the viewpoint of ensuring the durability and safety of each battery cell, charging is prohibited when the battery cell with the highest SOC (or both-ends voltage) reaches the set upper limit SOC (or upper-end both-ends voltage value). It is necessary to inhibit discharge when the battery cell having the lowest SOC (or both-end voltage) reaches the set lower limit SOC (or lower-limit both-end voltage value). Therefore, when SOC variation occurs in each battery cell, the usable capacity of the battery is substantially reduced. For this reason, in order to equalize the SOC of each battery cell, it is necessary to detect the voltage across each battery cell.

  The detection of the voltage of each battery cell is performed for each block in which about 10 battery cells are connected in series using a plurality of voltage detection ICs capable of detecting the voltage of about 10 battery cells. In some cases, the detection electric circuit connecting the battery cells is disconnected, and voltage detection becomes unstable. For this reason, the method of providing a disconnection detection circuit between the battery cell of a block and voltage detection IC is used. There are various types of disconnection detection circuits. For example, a capacitor and an on / off switch are connected in parallel with each battery cell in the block, the switch is turned on and the capacitor is discharged, and then the switch is turned off and the battery cell is turned off. There is a method in which the capacitor is charged by detecting the disconnection of the detection circuit by the magnitude of the charging speed or the voltage rise across the capacitor during a predetermined period (see, for example, Patent Document 1).

JP 2010-256155 A

  By the way, the voltage detection IC which detects the voltage of the battery cell as described in Patent Document 1 is supplied with operating power from a 12V or 24V auxiliary battery. However, if a battery has a configuration in which 100 battery cells are connected in series, and one voltage detection IC is used for a battery block composed of 10 battery cells, the voltage detection ICs are arranged at 10 locations. Will be. Usually, the voltage detection IC is provided adjacent to the battery block that performs voltage detection. In this case, it is necessary to lay a power supply circuit in each of the ten voltage detection ICs from the auxiliary battery. There was a problem that the structure of became complicated. For this reason, a method of supplying operating power from the battery block adjacent to the voltage monitoring IC to the voltage detection IC has been studied. In this case, the positive electrode and the negative electrode of the battery block are connected to the voltage detection IC by the positive electrode and the negative electrode circuit, and operating power is supplied from the battery block to the voltage detection IC. In addition, the voltage detection IC detects the voltage of the positive electrode and the negative electrode circuit as the positive electrode potential of the battery block and the negative electrode potential of the voltage block, and detects the voltage of each battery cell using the positive electrode potential and the negative electrode potential of the battery block as reference potentials. . The positive electrode and the negative electrode circuit are provided with a power connector that enables disconnection and connection of each circuit. When the contact resistance of the power connector increases, the potential of the positive electrode of the battery block that is referred to by the voltage detection IC, the negative electrode The potential of the battery cell fluctuates, the detection potential of the battery cell fluctuates, and the accuracy of voltage detection may decrease.

  Therefore, an object of the present invention is to accurately detect the voltage of each battery cell in a voltage monitoring apparatus to which operating power is supplied from a battery block in which battery cells that perform voltage monitoring are connected in series.

  The battery monitoring device of the present invention includes a monitoring IC that receives operating power from a battery block in which a plurality of battery cells that perform voltage monitoring are connected in series and monitors the voltage of each battery cell, and a positive terminal of the battery block. And a positive electrode and a negative power supply connector respectively connected to a negative electrode terminal and a positive electrode and a negative electrode electric circuit that are respectively connected to the negative electrode terminal and supply operating power to the monitoring IC, wherein the monitoring IC includes the positive electrode and the negative electrode A voltage drop detection unit that detects a voltage drop of the positive or negative power connector when an operating current flows through an electric circuit, and a resistance increase of the positive or negative power connector based on a voltage value detected by the voltage drop detection unit And a control unit for determining.

  The battery monitoring device of the present invention is provided with a voltage drop detection unit for the positive electrode and the negative electrode connector to detect the voltage drop of each connector, thereby determining the increase in resistance of the positive electrode and the negative electrode. Can accurately detect the voltage of each battery cell.

  In the battery monitoring device of the present invention, a plurality of detection electric circuits that respectively connect both ends of each battery cell and a plurality of input terminals of the monitoring IC, the monitoring IC side of the positive electrode power connector of the positive electrode electric circuit, and the A block voltage detection circuit for connecting a block voltage input terminal of the monitoring IC, and a ground circuit for connecting the monitoring IC side of the negative power connector of the negative circuit and the ground input terminal of the monitoring IC, The voltage drop detection unit detects a voltage between the block voltage detection circuit and a first detection circuit that connects the positive electrode of the first battery cell in the most positive electrode stage of the battery block and the monitoring IC. A second power for detecting a voltage between the sensor, the ground circuit, a second detection circuit that connects the negative electrode of the second battery cell in the most negative stage of the battery block and the monitoring IC. And the control unit increases the resistance of the positive or negative power connector when a voltage value detected by the first voltage sensor or the second voltage sensor is equal to or greater than a predetermined threshold value. It is also preferable to make a determination.

  The battery monitoring device according to the present invention determines that the resistance of the positive electrode and the negative electrode has increased when the voltage value detected by providing the voltage drop detection unit of the positive electrode and the negative electrode connector is greater than or equal to a predetermined threshold. Even if is supplied, voltage detection of each battery cell can be performed with high accuracy.

  In the battery monitoring device of the present invention, a plurality of detection electric circuits that respectively connect both ends of each battery cell and a plurality of input terminals of the monitoring IC, the monitoring IC side of the positive electrode power connector of the positive electrode electric circuit, and the A block voltage detection circuit for connecting a block voltage input terminal of the monitoring IC, and a ground circuit for connecting the monitoring IC side of the negative power connector of the negative circuit and the ground input terminal of the monitoring IC, The voltage drop detection unit detects a voltage between the block voltage detection circuit and a third detection circuit that connects the negative electrode of the first battery cell in the most positive stage of the battery block and the monitoring IC. A fourth electric current for detecting a voltage between the sensor, the ground electric circuit, and a fourth detection electric circuit connecting the positive electrode of the second battery cell in the most negative electrode stage of the battery block and the monitoring IC; A voltage difference between the voltage detected by the third voltage sensor and the voltage of the first battery cell, or the voltage detected by the fourth voltage sensor and the second battery cell. It is also preferable to determine an increase in resistance of the positive or negative power supply connector based on a voltage difference from the voltage.

  Since the battery monitoring device of the present invention determines the resistance increase of the positive electrode and the negative electrode connector based on the voltage difference between the detection voltage and the voltage of the battery cell, the voltage of each battery cell can be detected with high accuracy.

  In the battery monitoring device of the present invention, the first detection connector disposed in the first detection electric circuit connecting the positive electrode of the first battery cell and the monitoring IC, the negative electrode of the second battery cell, and the monitoring IC A second detection connector disposed in a second detection electric circuit to be connected, wherein the control unit has a predetermined absolute value of a voltage difference between the voltage detected by the third voltage sensor and the voltage of the first battery cell. If the voltage is lower than the voltage of the first battery cell, it is determined that the positive power supply connector and the first detection connector are normal, and the voltage detected by the third voltage sensor is greater than the voltage of the first battery cell by a predetermined voltage or more. In this case, it is determined that the resistance of the first detection connector has increased, and the voltage detected by the third voltage sensor is smaller than the voltage of the first battery cell by a predetermined voltage or more, the positive electrode The resistance of the power connector If the absolute value of the voltage difference between the voltage detected by the fourth voltage sensor and the voltage of the second battery cell is less than a predetermined voltage, the negative power connector and the second When the detection connector is determined to be normal and the voltage detected by the fourth voltage sensor is greater than the voltage of the second battery cell by a predetermined voltage or more, the resistance of the second detection connector is increased. If the voltage detected by the fourth voltage sensor is smaller than the voltage of the second battery cell by a predetermined voltage or more, it is determined that the resistance of the negative power connector is increased. Is preferred.

  Since the battery monitoring device of the present invention determines the resistance increase of the positive electrode and the negative electrode connector and the resistance increase of the detection connector based on the voltage difference between the detection voltage and the voltage of the battery cell, the voltage detection of each battery cell can be performed with higher accuracy. Can do.

  INDUSTRIAL APPLICABILITY The present invention provides an effect that voltage detection of each battery cell can be performed with high accuracy in a voltage monitoring device in which operating power is supplied from a battery block in which battery cells that perform voltage monitoring are connected in series.

It is a systematic diagram which shows the structure of the battery monitoring apparatus in embodiment of this invention. It is a circuit diagram which shows the charge of the capacitor | condenser in the case of detecting the resistance of the detection connector of the battery monitoring apparatus in embodiment of this invention, and the disconnection of a detection electric circuit. It is a circuit diagram which shows the discharge of the capacitor | condenser in the case of detecting the resistance of the detection connector of the battery monitoring apparatus in embodiment of this invention, and the disconnection of a detection electric circuit. It is a graph which shows the time change of the capacitor voltage at the time of discharging a capacitor in Drawing 2B. It is a flowchart which shows resistance detection operation | movement of the positive electrode power connector of the battery monitoring apparatus in embodiment of this invention. It is a flowchart which shows resistance detection operation | movement of the negative electrode power connector of the battery monitoring apparatus in embodiment of this invention. It is a circuit diagram which shows the flow of the electric current in the case of resistance detection of the positive electrode and negative electrode power supply connector in embodiment of this invention. It is a systematic diagram which shows the structure of the battery monitoring apparatus in other embodiment of this invention. It is a flowchart which shows the resistance detection operation | movement of the positive electrode power supply connector of the battery monitoring apparatus in other embodiment of this invention, and a 1st detection connector. It is a flowchart which shows resistance detection operation | movement of the negative electrode power supply connector of the battery monitoring apparatus in other embodiment of this invention, and a 2nd detection connector. It is a circuit diagram which shows the flow of the electric current in the case of resistance detection of the positive electrode and negative electrode power supply connector in the other embodiment of this invention, and a 1st, 2nd detection connector.

<Configuration of voltage monitoring device>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the battery monitoring device 500 of the present embodiment is supplied with an operating voltage from the battery block 10 in which about 8 to 16 battery cells 21 to 24 are connected in series, and each battery cell 21 to 24. The monitoring IC 100 for detecting each voltage of the battery, the detection electric circuits 51, 61, 71, 81, 91, 96 connecting the battery cells 21 to 24 and the monitoring IC 100, the positive terminal 11 of the battery block 10 and the negative A positive electrode circuit 31 and a negative electrode circuit 41 connected to the extreme 13 and supplying operating power to the monitoring IC 100 are provided. In FIG. 1, the intermediate battery cells of the battery block 10, the detection electric circuit, the input terminal, a voltage sensor described later, and a switch are not shown. On the battery block 10 side of each detection electric circuit 51, 61, 71, 81, 91, 96, each detection electric circuit 51, 61, 71, 81, 91, 96 is intermediate between each battery cell 21-24 and the monitoring IC side. The detection connectors 52, 62, 72, 82, 92, and 97 that can be disconnected and connected are provided. In addition, the positive and negative electrode circuits 31 and 41 can be disconnected and connected to the battery block 10 side of the positive and negative electrode circuits 31 and 41 between the positive electrode end 11 and the negative electrode end 13 of the battery block 10 and the monitoring IC. Positive and negative power supply connectors 32, 42 are provided. Further, fuses 53, 63, 73, 83, 93, 98 are provided on the monitoring IC 100 side of the respective detection connectors 52, 62, 72, 82, 92, 97 of the respective detection electric circuits 51, 61, 71, 81, 91, 96. The fuses 33 and 43 are arranged on the monitoring IC 100 side of the power connectors 32 and 42.

  The positive electrode circuit 31 is connected to the high voltage input terminal 101 of the monitoring IC. The connection point 39 on the monitoring IC 100 side of the positive power supply connector 32 of the positive electrode circuit 31 and the block voltage input terminal 102 of the monitoring IC 100 are connected by a block voltage detection circuit 37. A resistor 35 is connected in series to the block voltage detection circuit 37, and the resistor 35 and the block voltage input terminal 102 of the block voltage detection circuit 37 are connected to the ground via a capacitor 36. The negative electrode circuit 41 is connected to a ground circuit 47 connected to the ground input terminal 103 of the monitoring IC 100 at a connection point 49 on the monitoring IC 100 side of the negative power connector 42.

  The monitoring IC 100 is connected to each of the battery cells 21 to 24 and extends from the input terminals 111 to 116 to the detection electric circuits 51, 61, 71, 81, 91, 96, and the detection electric circuits 51, 61, 71, 96, respectively. 81, 91, 96 are connected in parallel with the battery cells 21-24, voltage sensors 131-134 for detecting the voltages of the battery cells 21-24, and the detection electric circuits 51, 61, 71, 81, 91. , 96 are connected in parallel with the voltage sensors 131 to 134, and switches 141 to 144 for turning on / off the connection between the detection electric circuits 51, 61, 71, 81, 91, 96 are provided. Further, each battery cell is provided in each detection electric circuit 51, 61, 71, 81, 91, 96 between each input terminal 111-116 of the monitoring IC 100 and each detection connector 52, 62, 72, 82, 92, 97. Capacitors 55, 65, 75, 95 and Zener diodes are connected in parallel with 21 to 24, and the detection electric circuits 51, 61, 71, 81 between the capacitors 55, 65, 75, 95 and the Zener diodes are connected. , 91, 96 are connected to resistors 54, 64, 74, 84, 94, 99, respectively.

  The connection point 39, which is one end of the block voltage detection circuit 37, and the input terminal 121 of the monitoring IC 100 and between the input terminal 121 and the detection circuit 51 inside the monitoring IC 100 are connected by a voltage detection circuit 38, A voltage sensor 201 is disposed in the voltage detection circuit 38 inside the monitoring IC 100. In addition, the connection point 49 which is one end of the ground electric circuit 47 and the input terminal 122 of the monitoring IC 100 and the input terminal 122 and the detection electric circuit 61 inside the monitoring IC 100 are connected by the voltage detection electric circuit 48 and are monitored. A voltage sensor 202 is disposed in the voltage detection circuit 48 inside the IC. The voltage sensor 201 and the voltage sensor 202 constitute a voltage drop detection unit 200 as a unit.

  The monitoring IC 100 includes a control unit 300 that performs information processing and calculation. The voltage sensors 131 to 134, 201, and 202 inside the monitoring IC 100 are connected to the control unit 300, and the detected voltage information is input to the control unit 300. In addition, each of the switches 141 to 144 in the monitoring IC 100 is configured to be turned on / off according to a command from the control unit 300. The control unit 300 is connected to the battery ECU, which is a higher-level control device, via the data bus 301, and transmits data such as the detected voltage of each battery cell 21 to 24 to the battery ECU and receives a command from the battery ECU. To do. In FIG. 1, a one-dot chain line indicates a signal line.

  As shown in FIG. 1, the high voltage input terminal 101 is connected to the positive terminal 11 of the battery block 10, and the ground input terminal 103 of the battery monitoring device 500 is connected to the negative terminal 13 of the battery block 10. When operating power for operating the monitoring IC 100 is supplied from the battery block 10, the circuit R1 through which current flows is [positive terminal 11 → high voltage input terminal 101 → monitoring IC 100 → ground input terminal 103 → negative terminal 13]. Operating current flows.

<Operation of determining resistance of detection connector in voltage monitoring device>
Before describing the resistance increase determination operation of each power connector 32, 42 of the voltage monitoring device 500 described above, the resistance increase determination operation of each detection connector 52, 62, 72, 82, 92, 97 will be described with reference to FIGS. 2A and 2B. This will be briefly described with reference to FIG.

  As shown in FIG. 2A, the control unit 300 turns on only the switch 143 from the state where the switches 141, 143, and 144 are turned off. Then, the electric charge accumulated in the capacitor 75 is discharged through the switch 143. Therefore, as shown in FIG. 2A, [battery cell 23 → battery cell 21 → detection electric circuit 51 → detection connector 52 → capacitor 55 → detection electric circuit 71 → switch 143 → detection electric circuit 91 → detection connector 92 → battery cell 23] and current [Battery cell 24 → battery cell 23 → detection electric circuit 71 → detection connector 72 → switch 143 → detection electric circuit 91 → capacitor 95 → detection electric circuit 96 → detection connector 97 → battery cell 24] And a circuit R11 (shown by a solid line) through which a current flows are formed, and the capacitor 55 and the capacitor 95 are charged with electric charges from the battery cells 21, 23, 24. The voltage across each capacitor 55, 95 is the battery cell 2 The voltage rises to VC2, which is an individual voltage. The controller 300 turns off the switch 143 after charging the capacitors 55 and 95 for a predetermined time. Then, the circuits R10 and R11 shown in FIG. 2A are cut off. The voltage across each capacitor 55, 95 is the total voltage VC2 of each battery cell 21, 23 or 23, 24, and is higher than the single voltage VC1 of each battery cell 21, 23, 24. Therefore, when the switch 143 is turned off. 2B, [capacitor 55 → detection circuit 51 → detection connector 52 → battery cell 21 → detection connector 72 → detection circuit 71 → capacitor 55] and a circuit R12 (indicated by a broken line) through which a current flows, 95 → detection circuit 91 → detection connector 92 → battery cell 24 → detection connector 97 → detection circuit 96 → capacitor 95] and a circuit R13 (shown by a solid line) through which current flows are formed. The voltage drops to the voltage VC1 of each battery cell 21, 24, that is, the voltage of one battery cell.

  FIG. 3 shows the voltage drop across the capacitors 55 and 95 with respect to the time after the switch 143 is turned off. The solid line a shown in FIG. 3 shows the voltage change when the detection connectors 52 and 92 are normal and the resistance is not increased, and the broken line b is the voltage when the resistances of the detection connectors 52 and 92 are increased. The alternate long and short dash line c indicates a change in voltage when the detection electric circuits 51 and 91 are disconnected.

  As shown by the solid line a in FIG. 3, when the detection connectors 52 and 92 are normal and there is no increase in resistance, the voltage at both ends of the capacitors 55 and 95 rapidly starts from VC2 (voltage for two battery cells). The voltage drops to VC1 (voltage for one battery cell). Therefore, the voltage across the capacitors 55 and 95 detected by the voltage sensors 131 and 134 at time t2 shown in FIG. 3 is VC1. On the other hand, when the resistances of the detection connectors 52 and 92 are increased, as shown by the broken line b in FIG. 3, it takes time to discharge the capacitors 55 and 95. Therefore, the voltage at time t2 shown in FIG. The voltage across the capacitors 55 and 95 detected by the sensors 131 and 134 is VC3 that is greater than VC1. In addition, when the detection electric circuits 51 and 91 are disconnected, the voltages of the capacitors 55 and 95 do not decrease from the voltage VC2 for two battery cells, so the voltage sensors 131 and 134 at time t2 shown in FIG. The voltage across the capacitors 55 and 95 detected by the above is VC2.

  The control unit 300 determines that the detection connectors 52 and 92 are normal if the voltages detected by the voltage sensors 131 and 134 at time t2 in FIG. 3 are VC1, respectively, and detects if the detected voltage is VC3. If it is determined that the resistances of the connectors 52 and 92 are increased and the detected voltage is VC2, it is determined that a disconnection has occurred in the detection electric circuits 51 and 91. When the control unit 300 determines that the resistances of the detection connectors 52 and 92 are increased, or when it is determined that the detection electric circuits 51 and 91 are disconnected, the voltage of the voltage cells 21 to 24 is determined. Since the detection accuracy may decrease, a fail signal is output to the battery ECU via the data bus 301.

  Although the detection of the resistance increase of the detection connectors 52 and 92 has been described above, the control unit 300 detects the resistance increase detection of the detection connectors 72 and 97 by turning on and off the switch 144 next to the switch 143. Hereinafter, the control unit 300 turns on and off the switches one by one from the positive electrode side to the negative electrode side of the battery block 10, thereby increasing the resistance of each detection connector 52, 62, 72, 82, 92, 97. Alternatively, disconnection determination of the detection electric circuit is performed.

<Operation of Determining Resistance Increase of Positive and Negative Power Supply Connectors in Voltage Monitoring Device 500>
Next, with reference to FIGS. 4A, 4B, and 5, the resistance increase determination of the positive and negative power connectors 32 and 42 will be described. In the following description, it is assumed that each detection connector 52, 62, 72, 82, 92, 97 is determined to be normal.

As shown in step S101 of FIG. 4A, the control unit 300 uses the voltage sensor 201 shown in FIG.
The voltage Vs1 is detected by the (first voltage sensor). The voltage sensor 201 detects a voltage between the block voltage detection circuit 37 and the detection circuit 51 connected to the positive electrode of the battery cell 21 (first battery cell). The block voltage detection circuit 37 is connected to the positive electrode of the battery cell 21 (first battery cell) in the most positive electrode stage of the battery block 10 via the positive power supply connector 32. The detection electric circuit 51 (first detection electric circuit) is connected to the positive electrode of the battery cell 21 via the detection connector 52. Therefore, since both ends of the voltage sensor 201 are both connected to the positive electrode of the battery cell 21, when the resistances of the positive power supply connector 32 and the detection connector 52 are very small, the detection voltage is zero. Further, as described above, the voltage drop at the positive power supply connector 32 when the operating power is supplied to the monitoring IC 100 through the circuit R1 shown in FIG. 5 is very small, and the block voltage input terminal 102 of the monitoring IC 100 5, a voltage equivalent to the positive voltage of the battery block 10 is input, so that the monitoring IC 100 can accurately detect the positive voltage of the battery block 10.

  On the other hand, when the resistance of the positive power supply connector 32 increases, the voltage on the monitoring IC 100 side of the positive power supply connector 32 causes a voltage drop ΔVp due to the current flowing from the battery block 10 to the monitoring IC 100 through the circuit R1. In this case, as described above, since the detection connector 52 is normal and the resistance is almost zero, the voltage sensor 201 detects the voltage of the voltage drop ΔVp (see the circuit R3 indicated by the one-dot chain line). Further, since a voltage lower than the positive voltage of the battery block 10 by ΔVp is input to the block voltage input terminal 102 of the monitoring IC 100 (see the broken line R2), the reference potential for detecting the voltage of the battery cells 21 to 24 is used. Deviation occurs, and the detection of the voltage of the battery cells 21 to 24, particularly the battery cell 21, becomes inaccurate.

  Therefore, when the voltage Vs1 detected by the voltage sensor 201 is equal to or higher than a predetermined threshold as shown in step S102 of FIG. 4A, the control unit 300 determines the resistance of the positive power supply connector 32 as shown in step S104 of FIG. 4A. When the voltage Vs1 detected by the voltage sensor 201 is less than the predetermined threshold value, it is determined that the positive power supply connector 32 is normal as shown in step S103 of FIG. Here, the predetermined voltage can be freely determined, but may be a voltage that does not reduce the voltage detection accuracy of the battery cells 21 to 24.

  Similarly, the control unit 300 detects the voltage Vs2 by the voltage sensor 202 (second voltage sensor) as shown in Step S105 of FIG. 4B. The voltage sensor 202 detects a voltage between the ground electric circuit 47 and the detection electric circuit 61 connected to the negative electrode of the battery cell 22 (second battery cell). The ground electric circuit 47 is connected to the negative electrode of the battery cell 22 (second battery cell) at the most negative electrode stage of the battery block 10 via the negative electrode power connector 42. The detection electric circuit 61 (second detection electric circuit) is connected to the negative electrode of the battery cell 22 via the detection connector 62. Accordingly, since both ends of the voltage sensor 202 are both connected to the negative electrode of the battery cell 22, when the resistances of the negative power supply connector 42 and the detection connector 62 are very small, the detection voltage is zero. Further, as described above, when the operating power is supplied to the monitoring IC 100 through the circuit R1 shown in FIG. 5, the voltage drop at the negative power connector 42 is very small, and the ground input terminal 103 of the monitoring IC 100 The voltage is equal to the negative voltage of the battery block 10, and the monitoring IC 100 can accurately detect the positive voltage of the battery block 10.

  On the other hand, when the resistance of the negative power supply connector 42 increases, the voltage of the ground input terminal 103 of the monitoring IC 100 becomes a voltage or potential that is lower by the voltage drop ΔVn due to the current flowing through the circuit R1. In this case, as described above, since the detection connector 62 is normal and the resistance is almost zero, the voltage sensor 202 detects the voltage of the voltage drop ΔVn (see the circuit R4 indicated by the one-dot chain line). Further, since a voltage or potential lower by ΔVn than the negative voltage of the battery block 10 is input to the ground input terminal 103 of the monitoring IC 100, a deviation occurs in the reference voltage when detecting the voltages of the battery cells 21 to 24. The detection of the voltage of the battery cells 21 to 24 becomes inaccurate.

  Therefore, when the voltage Vs2 detected by the voltage sensor 202 is equal to or higher than a predetermined threshold as shown in step S106 of FIG. 4B, the controller 300 determines the resistance of the negative power connector 42 as shown in step S108 of FIG. If the voltage Vs2 detected by the voltage sensor 202 is less than the predetermined threshold, it is determined that the negative power connector 42 is normal as shown in step S107 of FIG. 4B. Here, the predetermined voltage can be freely determined, but as with the positive power supply connector 32, the predetermined voltage may be set to a voltage that does not decrease the voltage detection accuracy of the battery cells 21 to 24. As described above, the control unit 300 can determine an increase in resistance of the positive and negative power supply connectors 32 and 42 depending on whether or not the voltages of the voltage sensors 201 and 202 are equal to or higher than a predetermined threshold.

  When the control unit 300 determines that the resistance of the positive or negative power supply connectors 32 and 42 is increased in step S104 of FIG. 4A or step S108 of FIG. 4A, the voltage detection accuracy of the voltage cells 21 to 24 is increased. It is determined that there is a possibility of a decrease, and a fail signal is output to the battery ECU via the data bus 301.

  As described above, the battery monitoring device 500 of the present embodiment has the positive and negative power connector 32 when operating power is supplied from the battery block 10 in which the battery cells 21 to 24 that perform voltage monitoring are connected in series. , 42 can be easily determined, so that the voltage detection of each of the battery cells 21-24 can be performed in a state where the voltage detection accuracy of each of the battery cells 21-24 is lowered due to the increase in the resistance of each of the power connectors 32, 42. Since the voltage detection of each battery cell 21-24 is performed in a state in which each power supply connector 32, 42 is normal and the voltage detection accuracy of each battery cell 21-24 can be ensured, the voltage of each battery cell 21-24 is accurate. The effect of being able to detect well is produced.

  Next, another embodiment of the present invention will be described with reference to FIGS. Components similar to those described above with reference to FIGS. 1 to 5 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 6, the battery monitoring apparatus 600 of the present embodiment detects and detects a block voltage detection circuit 37 instead of the voltage sensors 201 and 202 of the battery monitoring apparatus 500 described above with reference to FIGS. 1 to 5. A voltage sensor 203 for detecting a voltage between the electric circuit 71 and a voltage sensor 204 for detecting a voltage between the ground electric circuit 47 and the detection electric circuit 81 are provided, and a voltage detection electric circuit 38 in which the voltage sensor 203 is arranged. Connects the connection point 39 at one end of the block voltage detection circuit 37 and the detection circuit 71 inside the monitoring IC 100 via the input terminal 123 of the monitoring IC 100, and the voltage detection circuit 48 in which the voltage sensor 204 is arranged is monitored. The connection point 49 at one end of the ground circuit 47 and the detection circuit 81 inside the monitoring IC 100 are connected via the input terminal 124 of the IC 100. Note that the voltage sensors 203, 204, 131, and 132 shown in FIG.

  In the battery monitoring apparatus 600 of the embodiment shown in FIG. 6, the resistance increase determination of each detection connector 52, 62, 72, 82, 92, 97 and the disconnection determination of each detection electric circuit 51, 61, 71, 81, 91, 96 are This is the same as described above with reference to FIGS.

<Resistance increase determination operation of positive and negative power connector in voltage monitoring device 600>
Next, with reference to FIG. 7A, 7B, and FIG. In the following description, it is assumed that it is determined that all the detection connectors 72, 92, 97, 82 other than the detection connectors 52, 62 are normal.

  First, the resistance increase determination of the positive power supply connector 32 and the detection connector 52 will be described. As shown in step S201 of FIG. 7A, the control unit 300 detects the voltage Vb1 of the battery cell 21 (first battery cell) by the voltage sensor 131 shown in FIG. Next, the controller 300 detects the voltage Vs3 by the voltage sensor 203 as shown in step S202 of FIG. 7A. The voltage sensor 203 detects a voltage between the block voltage detection circuit 37 and the detection circuit 71 connected to the negative electrode of the battery cell 21 (first battery cell). The block voltage detection circuit 37 is connected to the positive electrode of the battery cell 21 (first battery cell) in the most positive electrode stage of the battery block 10 via the positive power supply connector 32. The detection electric circuit 71 is connected to the negative electrode of the battery cell 21 via the detection connector 72. Now, since the resistance of the detection connector 72 is very small, when the resistance of the positive power supply connector 32 is very small, the voltage sensor 203 is detected by a circuit R6 passing through the positive power supply connector 32 as shown by a one-dot chain line in FIG. The voltage of the battery cell 21 is detected. On the other hand, the voltage sensor 131 detects the voltage of the battery cell 21 by a circuit R5 indicated by a broken line in FIG. Now, since the resistance of the detection connector 72 is very small, when the resistance of the detection connector 52 is very small, the voltage Vb1 detected by the voltage sensor 131 is the voltage of the battery cell 21. Accordingly, when the resistances of the positive power supply connector 32 and the detection connector 52 are very small, the voltage Vs3 detected by the voltage sensor 203 and the voltage Vb1 detected by the voltage sensor 131 are the same voltage.

  Here, when the resistance of the positive power supply connector 32 increases, the voltage on the monitoring IC 100 side of the positive power supply connector 32 is reduced by the voltage drop ΔVp generated by the current flowing from the battery block 10 to the monitoring IC 100 through the circuit R1. The voltage is lower than the voltage at the positive electrode end 11 of the block 10, that is, the voltage at the positive electrode side of the battery cell 21. For this reason, the voltage Vs3 detected by the voltage sensor 203 is lower than the voltage of the battery cell 21 by the voltage drop ΔVp (see the circuit R6 indicated by the alternate long and short dash line). On the other hand, when the detection connectors 52 and 72 are normal and the resistance is almost zero, the voltage sensor 131 detects the voltage of the battery cell 21 regardless of the increase in resistance of the positive power supply connector 32. For this reason, when the resistance of the positive power supply connector 32 increases, the voltage Vs3 detected by the voltage sensor 203 becomes smaller than the voltage Vb1 detected by the voltage sensor 131.

  Further, when the resistance of the detection connector 52 (first detection connector) increases, a voltage drop ΔVp1 occurs at both ends of the detection connector 52. When the detection connector 72 is normal and the resistance is almost zero, the voltage sensor 131 detects a voltage that is lower than the voltage of the battery cell 21 by a voltage drop ΔVp1 (see the circuit R5 indicated by a broken line). On the other hand, when the resistances of the positive power supply connector 32 and the detection connector 72 are almost zero, the voltage sensor 203 detects the voltage of the battery cell 21 regardless of the increase in the resistance of the detection connector 52. For this reason, when the resistance of the detection connector 52 (first detection connector) increases, the voltage Vs3 detected by the voltage sensor 203 becomes larger than the voltage Vb1 detected by the voltage sensor 131.

  Therefore, as shown in step S203 of FIG. 7A, the controller 300 calculates the absolute value ΔVd3 of the voltage difference between the voltage Vs3 detected by the voltage sensor 203 and the voltage Vb1 detected by the voltage sensor 131, and the step of FIG. As shown in S204, it is determined whether or not the absolute value ΔVd3 of the voltage difference is less than a predetermined voltage. If the absolute difference ΔVd3 of the voltage difference is less than the predetermined voltage (when YES is determined in step S204 in FIG. 7A), the process proceeds to step S205 in FIG. 7A and both the positive power supply connector 32 and the detection connector 52 are normal. Determine that there is.

  In addition, when it is determined NO in step S204 of FIG. 7A, the control unit 300 proceeds to step S206 of FIG. 7A, and the voltage Vs3 detected by the voltage sensor 203 is higher than the voltage Vb1 detected by the voltage sensor 131. Determine if it is greater than the voltage. When it is determined YES in step S206 of FIG. 7A, the control unit 300 proceeds to step S207 of FIG. 7A and determines that the resistance of the detection connector 52 (first detection connector) is increased.

  Further, if the control unit 300 determines NO in step S206 of FIG. 7A, that is, if the voltage Vs3 detected by the voltage sensor 203 is smaller than the voltage Vb1 detected by the voltage sensor 131, the control unit 300 Proceeding to step S208 of 7A, it is determined that the resistance of the positive power supply connector 32 has increased. As described above, the control unit 300 can determine the resistance increase of the positive power supply connector 32 and the detection connector 52 based on the voltage difference between the voltages detected by the voltage sensor 203 and the voltage sensor 131.

  When the control unit 300 determines in step S207 or step S208 in FIG. 7A that the resistance of the detection connector 52 or the positive power supply connector 32 is increased, the voltage detection accuracy of the voltage cells 21 to 24 may be decreased. And determines that there is a fail signal to the battery ECU via the data bus 301.

  Next, the resistance increase determination of the negative power supply connector 42 and the detection connector 62 will be described. As shown in step S301 of FIG. 7B, the controller 300 detects the voltage Vb2 of the battery cell 22 (second battery cell) by the voltage sensor 132 shown in FIG. Next, the controller 300 detects the voltage Vs4 by the voltage sensor 204 as shown in step S302 of FIG. 7B. The voltage sensor 204 detects a voltage between the ground electric circuit 47 and the detection electric circuit 81 connected to the positive electrode of the battery cell 22 (second battery cell). The ground electric circuit 47 is connected to the negative electrode of the battery cell 22 (second battery cell) at the most negative electrode stage of the battery block 10 via the negative electrode power connector 42. The detection electric circuit 81 is connected to the positive electrode of the battery cell 22 through the detection connector 82. Now, since the resistance of the detection connector 82 is very small, when the resistance of the negative power supply connector 42 is very small, the voltage sensor 204 is connected to the battery cell 22 by the circuit R8 that passes through the negative power supply connector 42 shown by a one-dot chain line in FIG. Will be detected. On the other hand, the voltage sensor 132 detects the voltage of the battery cell 22 by a circuit R7 indicated by a broken line in FIG. Now, since the resistance of the detection connector 82 is very small, the voltage Vb2 detected by the voltage sensor 132 becomes the voltage of the battery cell 22 when the resistance of the detection connector 62 is very small. Accordingly, when the resistances of the negative power supply connector 42 and the detection connector 62 are very small, the voltage Vs4 detected by the voltage sensor 204 and the voltage Vb2 detected by the voltage sensor 132 are the same voltage.

  Here, when the resistance of the negative power connector 42 increases, the voltage on the monitoring IC 100 side of the negative power connector 42 is higher than the voltage on the negative terminal 13 of the battery block 10, that is, the negative voltage of the battery cell 22. It becomes higher by the drop ΔVn. For this reason, the voltage Vs4 detected by the voltage sensor 204 is a voltage that is smaller than the voltage of the battery cell 22 by the voltage drop ΔVn (see the circuit R8 indicated by the one-dot chain line). On the other hand, when the detection connectors 62 and 82 are normal and the resistance is almost zero, the voltage sensor 132 detects the voltage of the battery cell 22 regardless of the resistance increase of the negative power supply connector 42. For this reason, when the resistance of the negative power supply connector 42 increases, the voltage Vs4 detected by the voltage sensor 204 becomes smaller than the voltage Vb2 detected by the voltage sensor 132.

  Further, when the resistance of the detection connector 62 (second detection connector) increases, a voltage drop ΔVn1 occurs at both ends of the detection connector 62. When the detection connector 82 is normal and the resistance is almost zero, the voltage sensor 132 detects a voltage that is smaller than the voltage of the battery cell 22 by a voltage drop ΔVn1 (see the circuit R7 indicated by a broken line). On the other hand, when the resistances of the negative power supply connector 42 and the detection connector 82 are almost zero, the voltage sensor 204 detects the voltage of the battery cell 22 regardless of the increase in the resistance of the detection connector 62. For this reason, when the resistance of the detection connector 62 (second detection connector) increases, the voltage Vs4 detected by the voltage sensor 204 becomes larger than the voltage Vb2 detected by the voltage sensor 132.

  Therefore, the control unit 300 calculates the absolute value ΔVd4 of the voltage difference between the voltage Vs4 detected by the voltage sensor 204 and the voltage Vb2 detected by the voltage sensor 132, as shown in Step S303 of FIG. As shown in S304, it is determined whether or not the absolute value ΔVd4 of the voltage difference is less than a predetermined voltage. When the absolute difference ΔVd4 of the voltage difference is less than the predetermined voltage (when YES is determined in step S304 in FIG. 7B), the process proceeds to step S305 in FIG. 7B, and both the negative power supply connector 42 and the detection connector 62 are normal. Judge that there is.

  In addition, when it is determined NO in step S304 in FIG. 7B, the control unit 300 proceeds to step S306 in FIG. 7B, and the voltage Vs4 detected by the voltage sensor 204 is higher than the voltage Vb2 detected by the voltage sensor 132. Determine if it is greater than the voltage. When it is determined YES in step S306 in FIG. 7B, the control unit 300 proceeds to step S307 in FIG. 7B and determines that the resistance of the detection connector 62 (second detection connector) is increased.

  Further, when the control unit 300 determines NO in step S306 of FIG. 7B, that is, when the voltage Vs4 detected by the voltage sensor 204 is smaller than the voltage Vb2 detected by the voltage sensor 132 by a predetermined voltage or more, FIG. Proceeding to step S308 of 7B, it is determined that the resistance of the negative power supply connector 42 has increased. As described above, the control unit 300 can determine the resistance increase of the negative power supply connector 42 and the detection connector 62 based on the voltage difference between the voltages detected by the voltage sensor 204 and the voltage sensor 132.

  If the control unit 300 determines in step S307 or step S308 in FIG. 7B that the resistance of the detection connector 62 or the negative power supply connector 42 is increased, the voltage detection accuracy of the voltage cells 21 to 24 may be reduced. And determines that there is a fail signal to the battery ECU via the data bus 301.

  The battery monitoring apparatus 600 according to the present embodiment has an effect that it can detect an increase in resistance of the detection connectors 52 and 62 (first and second detection connectors) in addition to the same effects as the battery monitoring apparatus 500 described above. Play.

  DESCRIPTION OF SYMBOLS 10 Battery block, 11 Positive electrode end, 13 Negative electrode end, 21-24 Battery cell, 31 Positive electrode circuit, 32 Positive electrode power supply connector, 33, 43, 53, 63, 73, 83, 93, 98 Fuse, 35, 54, 64, 74, 84, 94, 99 Resistance, 36, 55, 65, 75, 95 Capacitor, 37 Block voltage detection circuit, 38, 48 Voltage detection circuit, 39, 49 Connection point, 41 Negative circuit, 42 Negative power connector, 47 Ground Electrical circuit, 51, 61, 71, 81, 91, 96 Detection circuit, 52, 62, 72, 82, 92, 97 Detection connector, 100 Monitoring IC, 101 High voltage input terminal, 102 Block voltage input terminal, 103 Ground input terminal , 111-116, 121-124 input terminals, 131-134, 201-204 voltage sensors, 141-1 44 switch, 200, 210 voltage drop detection unit, 300 control unit, 301 data bus, 500, 600 battery monitoring device.

Claims (4)

A monitoring IC that receives operating power from a battery block in which a plurality of battery cells that perform voltage monitoring are connected in series, and monitors the voltage of each battery cell;
A positive electrode and a negative power supply connector respectively connected to a positive electrode end and a negative electrode end of the battery block and provided to a positive electrode and a negative electrode electric circuit that supply operating power to the monitoring IC;
A battery monitoring device comprising:
The monitoring IC is
A voltage drop detection unit that detects a voltage drop of the positive or negative power connector when an operating current flows through the positive and negative electrodes;
A control unit for determining a resistance increase of the positive or negative power connector based on a voltage value detected by the voltage drop detection unit;
A battery monitoring device comprising: The battery monitoring device according to claim 1,
A plurality of detection electric circuits respectively connecting the both ends of each battery cell and the plurality of input terminals of the monitoring IC;
A block voltage detection circuit that connects the monitoring IC side of the positive power supply connector of the positive circuit and a block voltage input terminal of the monitoring IC;
A ground circuit that connects the monitoring IC side of the negative power supply connector of the negative circuit and the ground input terminal of the monitoring IC;
The voltage drop detector is
A first voltage sensor that detects a voltage between the block voltage detection circuit and a first detection circuit that connects the positive electrode of the first battery cell in the most positive stage of the battery block and the monitoring IC;
A second voltage sensor for detecting a voltage between the ground electric circuit and a second detection electric circuit connecting the negative electrode of the second battery cell in the most negative electrode stage of the battery block and the monitoring IC;
The controller is
Determining that the resistance of the positive or negative power connector is increased when a voltage value detected by the first voltage sensor or the second voltage sensor is equal to or greater than a predetermined threshold;
A battery monitoring device. The battery monitoring device according to claim 1,
A plurality of detection electric circuits respectively connecting the both ends of each battery cell and the plurality of input terminals of the monitoring IC;
A block voltage detection circuit that connects the monitoring IC side of the positive power supply connector of the positive circuit and a block voltage input terminal of the monitoring IC;
A ground circuit that connects the monitoring IC side of the negative power supply connector of the negative circuit and the ground input terminal of the monitoring IC;
The voltage drop detector is
A third voltage sensor that detects a voltage between the block voltage detection circuit and a third detection circuit that connects the negative electrode of the first battery cell in the most positive stage of the battery block and the monitoring IC;
A fourth voltage sensor that detects a voltage between the ground circuit and a fourth detection circuit that connects the positive electrode of the second battery cell at the most negative electrode stage of the battery block and the monitoring IC;
The controller is
The positive electrode based on the voltage difference between the voltage detected by the third voltage sensor and the voltage of the first battery cell, or the voltage difference between the voltage detected by the fourth voltage sensor and the voltage of the second battery cell. Or determining an increase in resistance of the negative power connector,
A battery monitoring device. The battery monitoring device according to claim 3,
A first detection connector disposed in a first detection electric circuit connecting the positive electrode of the first battery cell and the monitoring IC;
A second detection connector disposed in a second detection circuit that connects the negative electrode of the second battery cell and the monitoring IC;
The controller is
When the absolute value of the voltage difference between the voltage detected by the third voltage sensor and the voltage of the first battery cell is less than a predetermined voltage, it is determined that the positive power supply connector and the first detection connector are normal. And
When the voltage detected by the third voltage sensor is greater than the voltage of the first battery cell by a predetermined voltage or more, it is determined that the resistance of the first detection connector has increased,
When the voltage detected by the third voltage sensor is smaller than the voltage of the first battery cell by a predetermined voltage or more, it is determined that the resistance of the positive power supply connector is increased,
When the absolute value of the voltage difference between the voltage detected by the fourth voltage sensor and the voltage of the second battery cell is less than a predetermined voltage, it is determined that the negative power supply connector and the second detection connector are normal. And
If the voltage detected by the fourth voltage sensor is greater than the voltage of the second battery cell by a predetermined voltage or more, it is determined that the resistance of the second detection connector has increased,
When the voltage detected by the fourth voltage sensor is smaller than the voltage of the second battery cell by a predetermined voltage or more, it is determined that the resistance of the negative power connector is increased.
A battery monitoring device.

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