JP2019021548A - Control device, battery monitoring system, and battery monitoring method - Google Patents

Abstract

To provide a control device, a battery monitoring system, and a battery monitoring method capable of detecting occurrence of a CID shutdown with a simple configuration.SOLUTION: A control device according to one embodiment detects occurrence of a current interrupt device (CID) shutdown when a battery monitoring device for detecting that a voltage equal to or higher than a predetermined voltage has been applied to a current path due to the occurrence of the CID shutdown in which the current path of the battery is shut down by a CID and grounding the current path when it is detected that the voltage of the current path has become equal to or higher than a second threshold value which is smaller than a first threshold value after it has been detected that the voltage of the current path is the first threshold value or more.SELECTED DRAWING: Figure 2

Description

  Embodiments disclosed herein relate to a control device, a battery monitoring system, and a battery monitoring method.

  Conventionally, when the internal pressure of a battery cell rises abnormally due to overcharge / discharge or overcurrent in the battery cell, CID interruption that mechanically interrupts the current path of the battery cell by CID (Current Interrupt Device) has occurred. There is a control device to detect (see, for example, Patent Document 1).

JP2013-243880A

  However, the conventional control device has a complicated configuration for detecting the occurrence of CID interruption. One aspect of the embodiments has been made in view of the above, and an object thereof is to provide a control device, a battery monitoring system, and a battery monitoring method that can detect the occurrence of CID interruption with a simple configuration. To do.

  The control device according to one aspect of the embodiment detects that a voltage higher than a predetermined voltage is applied to the current path by occurrence of CID interruption in which the current path of the battery is interrupted by a CID (Current Interrupt Device), and After detecting that the voltage of the current path is equal to or higher than the first threshold, the battery monitoring device for grounding the current path is detected to be equal to or lower than the second threshold smaller than the first threshold. In the case, the occurrence of the CID blocking is detected.

  The control device, the battery monitoring system, and the battery monitoring method according to one aspect of the embodiment can detect the occurrence of CID interruption with a simple configuration.

FIG. 1 is a functional block diagram showing the configuration of the battery monitoring system according to the embodiment. FIG. 2 is an explanatory diagram illustrating an example of the configuration of the battery monitoring device according to the embodiment. FIG. 3 is an explanatory diagram illustrating a state of the battery monitoring device and the microcomputer when the CID interruption according to the embodiment occurs. FIG. 4 is an explanatory diagram illustrating states of the battery monitoring device and the microcomputer when overcharging occurs according to the embodiment. FIG. 5 is an explanatory diagram of a determination method and a failure determination method between overcharge and CID interruption by the microcomputer according to the embodiment. FIG. 6 is a flowchart illustrating processing executed by the microcomputer according to the embodiment. FIG. 7 is a flowchart illustrating processing executed by the microcomputer according to the embodiment. FIG. 8 is a flowchart illustrating processing executed by the microcomputer according to the embodiment. FIG. 9 is an explanatory diagram illustrating an example of a configuration of a battery monitoring apparatus according to a modification of the embodiment. FIG. 10 is an explanatory diagram of a determination method and a failure determination method between overcharge and CID interruption by a microcomputer according to a modification of the embodiment.

  Hereinafter, embodiments of a battery monitoring device, a CID cutoff detection circuit, a battery monitoring system, and a battery monitoring method disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

  FIG. 1 is a functional block diagram illustrating a configuration of a battery monitoring system 100 according to the embodiment. FIG. 1 shows a schematic configuration of the battery monitoring system 100. An example of a specific configuration of the battery monitoring system 100 will be described later with reference to FIG.

  The battery monitoring system 100 is mounted on a vehicle such as a hybrid vehicle (HEV), an electric vehicle (EV), and a fuel cell vehicle (FCV) (not shown).

  The battery monitoring system 100 includes a battery pack 1 and a microcomputer (hereinafter referred to as “microcomputer 2”) which is an example of a control device. The battery pack 1 includes a battery pack in which a plurality of battery blocks 10 are connected in series, and a battery monitoring device 20 provided for each battery block 10.

  Each battery block 10 is, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and includes a plurality of battery cells 11 connected in series. Each battery cell 11 is provided with a CID (Current Interrupt Device) (not shown) that mechanically interrupts the current path when the internal pressure rises. For example, such an assembled battery is discharged when electric power is output to an electric motor that drives the vehicle, and is charged when electric power generated by regenerative braking of the electric motor is input.

  The battery monitoring device 20 monitors the charge state of each battery cell 11 included in the corresponding battery block 10 and notifies the microcomputer 2 of the state of the battery block 10. Each battery monitoring device 20 is provided on a satellite substrate (hereinafter simply referred to as “substrate”) disposed at a position spaced apart from each other.

  Each of the battery monitoring devices 20 includes a monitoring IC (Integrated Circuit) 21, an overcharge detection unit 22, and a CID interruption detection unit 23. The monitoring IC 21 detects the voltage of the battery block 10 or the battery cell 11 and outputs it to the microcomputer 2.

  The overcharge detection unit 22 detects the occurrence of overcharge in the battery block 10 and notifies the microcomputer 2 of the occurrence. Moreover, the CID interruption | blocking detection part 23 detects generation | occurrence | production of CID interruption | blocking by which the electric current path of the battery block 10 is interrupted | blocked mechanically by CID, and notifies the microcomputer 2.

  The microcomputer 2 is, for example, an electronic control unit (ECU: Electronic Control Unit). The microcomputer 2 performs charge / discharge control of the assembled battery based on the state of the battery block 10 notified from the battery monitoring device 20.

  For example, when the microcomputer 2 is notified of the occurrence of overcharge in the battery block 10 from the battery monitoring device 20, the microcomputer 2 performs charge control that suppresses charging of the assembled battery. When the occurrence of CID interruption is notified from the battery monitoring device 20, the microcomputer 2 may have caused overcharge / discharge or overcurrent. For example, charge / discharge for disconnecting a relay connecting the assembled battery and the electric motor. Take control.

  Next, an example of the configuration of the battery monitoring device 20 according to the embodiment will be described with reference to FIG. FIG. 2 is an explanatory diagram illustrating an example of the configuration of the battery monitoring device 20 according to the embodiment. Here, the description of the functions already described of the battery block 10, the monitoring IC 21, and the microcomputer 2 is omitted.

  As shown in FIG. 2, the battery monitoring device 20 includes a monitoring IC 21, an overcharge detection unit 22, a CID interruption detection unit 23, a voltage dividing circuit 24, and a fuse blowing circuit 25. The monitoring IC 21 operates with electric power supplied via the current path of the battery block 10 and bi-directionally transmits and receives information to and from the microcomputer 2.

  One end of the voltage dividing circuit 24 is connected to the high voltage side electrode of the battery block 10 via the fuse F, and the other end is connected to the low voltage side electrode (ground) of the battery block 10. The voltage dividing circuit 24 includes resistors R1 and R2 connected in series. The voltage of the battery block 10 divided by the resistors R1 and R2 is disconnected from the overcharge detection unit 22 and the CID from the connection point of the resistors R1 and R2. Output to the detector 23.

  The fuse blowing circuit 25 is connected in parallel with the voltage dividing circuit 24. Such a fuse blowing circuit 25 includes a resistor R3 and Zener diodes D1, D2 connected in series. The resistance value of the resistor R3 of the fuse blowing circuit 25 is set to an extremely small value as compared with the resistors R1 and R2 of the voltage dividing circuit 24.

  Further, the connection point of the Zener diodes D1 and D2 and the connection point of the resistors R1 and R2 of the voltage dividing circuit 24 are connected. The Zener diodes D1 and D2 do not flow current from the cathode to the anode even when the battery block 10 is overcharged. When the CID interruption occurs and the voltage exceeds a predetermined voltage higher than the overcharge state, the Zener diodes D1 and D2 The breakdown voltage is set so that a current flows to the anode.

  As a result, when the voltage of the battery block 10 is equal to or lower than the overcharged voltage, a current path is formed through the voltage dividing circuit 24 and the voltage of the battery block 10 divided by the resistors R1 and R2 of the voltage dividing circuit 24 is formed. The voltage is output to the overcharge detection unit 22 and the CID interruption detection unit 23.

  Moreover, when CID interruption | blocking generate | occur | produces in the battery block 10, the electric current path which passes along the fuse blowing circuit 25 is formed, and the electric current path of the battery block 10 is grounded. At this time, as described above, since the resistance value of the resistor R3 of the fuse blowing circuit 25 is extremely lower than the resistors R1 and R2 of the voltage dividing circuit 24, a large current flows.

  In this way, the fuse blowing circuit 25 detects that a voltage higher than a predetermined voltage is applied to the current path due to the occurrence of CID interruption, grounds the current path, and flows a large current to blow the fuse F. The battery monitoring device 20 can be protected from overvoltage and overcurrent that occur in association with CID interruption.

  As described above, the circuit configured by the resistors R1 and R2 and the Zener diodes D1 and D2 functions as a cut-off voltage detection unit that detects that a voltage higher than a predetermined voltage is applied to the current path due to occurrence of CID cut-off.

  The overcharge detection unit 22 includes a power supply terminal 30, an input terminal 31, and an output terminal 32. Further, the overcharge detection unit 22 includes a comparator 33, a constant voltage source (hereinafter referred to as “LDO (Low Drop Out) 34”), a threshold adjustment unit 35, resistors R4, R5, R6, and R7, a capacitor C1, and a transistor. Tr1, Tr2 and photocoupler PC are provided.

  The power supply terminal 30 is connected to the high voltage side electrode of the battery block 10 via the fuse F, the resistor R8, and the transistor Tr. For example, when the ignition switch of the vehicle is turned on, the monitoring IC 21 turns on the transistor Tr and supplies the power supply voltage from the battery block 10 to the power supply terminal 30.

  The input terminal 31 is connected to the connection point of the resistors R1 and R2 in the voltage dividing circuit 24 via the connection point of the Zener diodes D1 and D2 in the fuse blowing circuit 25, and a voltage corresponding to the voltage of the battery block 10 is input. The The output terminal 32 is connected to the microcomputer 2.

  The resistor R4 has one end connected to the input terminal 31 and the other end connected to the non-inverting input terminal (+ terminal) of the comparator 33. A capacitor C1 is connected between the other end of the resistor R4 and the ground. The capacitor C1 functions as a filter that removes noise components contained in the voltage input from the input terminal 31.

  The LDO 34 has one end connected to the power supply terminal 30 and the other end connected to the inverting input terminal (− terminal) of the comparator 33. The LDO 34 generates a threshold voltage for overcharge detection from the power supply voltage input from the power supply terminal 30 and inputs the threshold voltage to the inverting input terminal (− terminal) of the comparator 33.

  The threshold voltage for overcharge detection is the maximum voltage when the battery block 10 is in a normal charge / discharge state. The threshold adjustment unit 35 adjusts the threshold voltage input to the comparator 33 according to the control of the microcomputer 2 when the microcomputer 2 performs failure diagnosis of the voltage dividing circuit 24, the overcharge detection unit 22, and the like. An example of failure diagnosis by the microcomputer 2 will be described later.

  The resistor R5 has one end connected to the power supply terminal 30 and the other end connected to a connection point between the output terminal of the comparator 33 and the base of the transistor Tr1. The resistor R6 has one end connected to the power supply terminal 30 and the other end connected to the collector of the transistor Tr1 and the base of the transistor Tr2.

  The transistor Tr1 is an NPN transistor, and an emitter is connected to the ground. The transistor Tr2 is a PNP transistor, and has an emitter connected to the power supply terminal 30 and a collector connected to one end of the resistor R7. The other end of the resistor R7 is connected to the anode of the light emitting diode D3 provided in the photocoupler PC.

  The photocoupler PC includes a light emitting diode D3 and a phototransistor Tr3. When a current flows through the light emitting diode D3, the phototransistor Tr3 is turned on and outputs a signal from the output terminal 32 to the microcomputer 2.

  The overcharge detection unit 22 performs overcharge in the battery block 10 when the voltage according to the voltage of the battery block 10 input from the input terminal 31 exceeds the threshold voltage for overcharge detection generated by the LDO 34. It detects and outputs a detection signal to the microcomputer 2.

  Specifically, in the overcharge detection unit 22, the comparator 33 compares the voltage corresponding to the voltage of the battery block 10 with the threshold voltage for overcharge detection. The comparator 33 outputs a Low level signal when the voltage corresponding to the voltage of the battery block 10 is equal to or lower than the threshold voltage. In such a case, the transistor Tr1 is maintained in the OFF state because a low level voltage is applied to the base.

  The comparator 33 outputs a high level signal when the voltage corresponding to the voltage of the battery block 10 exceeds the threshold voltage. In this case, the transistor Tr1 is turned on because a high level voltage is applied to the base.

  As a result, the transistor Tr2 is turned on with the base connected to the ground, and a current is supplied to the light emitting diode D3 of the photocoupler PC to turn on the phototransistor Tr3, and the detection signal is output from the photocoupler PC to the microcomputer 2.

  Thus, the photocoupler PC functions as a detection signal output unit that outputs a detection signal. The overcharge detection unit 22 can detect the occurrence of overcharge in the battery block 10 and notify the microcomputer 2 of the occurrence.

  As described above, the overcharge detection unit 22 detects the occurrence of overcharge by comparing the voltage input from the voltage dividing circuit 24 or the fuse blowing circuit 25 with the threshold voltage for overcharge detection. Therefore, when the battery monitoring device 20 detects the occurrence of overcharge in the battery block 10, the voltage dividing circuit 24 and the fuse blowing circuit 25 function as a part of the overcharge detection unit 22.

  The CID interruption detection unit 23 includes a power supply terminal 40, an input terminal 41, an output terminal 42, control terminals 43 and 44, a constant voltage source (hereinafter referred to as “LDO45”), a diode D4, a capacitor C2, transistors Tr4 and Tr5, And a resistor R9.

  The power supply terminal 40 is connected to the high voltage side electrode of the battery block 10 through the fuse F, the resistor R8, and the transistor Tr. For example, when the ignition switch of the vehicle is turned on, the monitoring IC 21 turns on the transistor Tr and supplies the power supply voltage from the battery block 10 to the power supply terminal 40.

  The input terminal 41 is connected to the connection point of the resistors R1 and R2 in the voltage dividing circuit 24 via the connection point of the Zener diodes D1 and D2 in the fuse blowing circuit 25, and a voltage corresponding to the voltage of the battery block 10 is input. The

  The output terminal 42 is connected to the anode of the light emitting diode D3 provided in the photocoupler PC. The control terminals 43 and 44 are connected to the monitoring IC 21, and a control signal is input from the monitoring IC 21.

  The LDO 45 has one end connected to the control terminal 43 and the other end connected to the diode D4. The LDO 45 generates a predetermined constant voltage from the power supply voltage input from the power supply terminal 40 and outputs it to the diode D4.

  The LDO 45 outputs a constant voltage and stops output according to a control signal input from the control terminal 43. The monitoring IC 21 stops the output of the constant voltage from the LDO 45 when performing the failure diagnosis described later of the CID interruption detection unit 23, and outputs the constant voltage from the LDO 45 during other periods.

  The transistor Tr4 is a PMOS transistor, the gate is connected to the input terminal 41, the source is connected to the cathode of the diode D4, and the drain is connected to the output terminal 42 via the resistor R9.

  The capacitor C2 has one end connected to a connection point between the source of the transistor Tr4 and the cathode of the diode D4, and the other end connected to the ground. The capacitor C2 is charged with a constant voltage when a constant voltage is output from the LDO 45.

  The transistor Tr5 is an NPN transistor, the base is connected to the control terminal 44, the collector is connected to the gate of the transistor Tr4, and the emitter is connected to the ground.

  The transistor Tr5 is switched between ON and OFF according to a control signal input from the control terminal 44. The monitoring IC 21 turns on the transistor Tr5 when performing a later-described failure diagnosis of the CID cutoff detection unit 23, and turns off the transistor Tr5 during other periods.

  When the voltage according to the voltage of the battery block 10 input from the input terminal 41 is lower than the threshold voltage for detecting CID interruption that is lower than the threshold voltage for detecting overcharge, the CID interruption detecting unit 23 The occurrence of the interruption is detected and a detection signal is output to the microcomputer 2.

  Specifically, when the CID interruption has not occurred, the voltage divided by the voltage dividing circuit 24 is input to the input terminal 41 of the CID interruption detection unit 23. In such a case, since the transistor Tr4 is a PMOS transistor, the voltage divided by the voltage dividing circuit 24 is applied to the gate, and the transistor Tr4 maintains the OFF state.

  For this reason, the CID interruption | blocking detection part 23 does not flow an electric current into the photocoupler PC. Accordingly, at this time, the photocoupler PC does not output a detection signal to the microcomputer 2 unless the overcharge detection unit 22 detects the occurrence of overcharge.

  In addition, when the CID interruption occurs, the voltage of the battery block 10 rises temporarily and then exceeds the breakdown voltage of the Zener diodes D1 and D2 included in the fuse fusing circuit 25, the current path from the voltage dividing circuit 24 Since it is switched to the fuse fusing circuit 25 and grounded, it descends rapidly.

  For this reason, when the voltage applied to the gate of the transistor Tr4 of the CID cutoff detection unit 23 decreases and falls below the threshold voltage for CID cutoff detection, the transistor Tr4 is turned on and passes a current to the photocoupler PC. As a result, a detection signal is output from the photocoupler PC to the microcomputer 2.

  In this way, the transistor Tr4 is connected between the charged capacitor C2 and the photocoupler PC, and corresponds to the output of the aforementioned cut-off voltage detection unit (circuit composed of the resistors R1, R2 and the Zener diodes D1, D2). Function as the first switching that turns ON.

  The transistor Tr5 functions as a second switching element that turns on the transistor Tr4 that is the first switching element. The photocoupler PC functions as a detection signal output unit that outputs a detection signal.

  The threshold voltage for detecting CID interruption here is lower than the threshold voltage for detecting overcharge, and is lower than the voltage of the charged capacitor C2. As described above, the CID interruption detection unit 23 can detect the occurrence of CID interruption in the battery block 10 and notify the microcomputer 2 of the occurrence.

  As described above, the CID interruption detection unit 23 detects the occurrence of CID interruption when the voltage input from the voltage dividing circuit 24 or the fuse blowing circuit 25 is lower than the threshold voltage for detecting CID interruption. Therefore, when the battery monitoring device 20 detects the occurrence of CID interruption in the battery block 10, the voltage dividing circuit 24 and the fuse blowing circuit 25 function as a part of the CID interruption detection unit 23.

  Thus, the battery monitoring device 20 can detect both the occurrence of overcharge and the occurrence of CID interruption in the battery block 10 by including the overcharge detection part 22 and the CID interruption detection part 23.

  In addition, the voltage dividing circuit 24 and the fuse blowing circuit 25 output a reference voltage for detecting the occurrence of overcharge to the overcharge detection unit 22 and the reference voltage for detecting the occurrence of CID interruption is CID. Output to the shutoff detection unit 23.

  That is, the voltage dividing circuit 24 and the fuse blowing circuit 25 are used for both overcharge detection and CID interruption detection by the battery monitoring device 20. For this reason, the battery monitoring device 20 can reduce the number of components and reduce the manufacturing cost compared to the case where a circuit for generating a reference voltage is provided for detecting overcharge and detecting CID interruption, respectively. Can be suppressed.

  Further, in the battery monitoring device 20, the photocoupler PC is used to notify the overcharge detection result from the overcharge detection unit 22 to the microcomputer 2 and to notify the detection result of CID interruption from the CID interruption detection unit 23 to the microcomputer 2. It is also used.

  As a result, the battery monitoring device 20 can reduce the number of components compared to a case where a photocoupler that notifies the detection result of overcharge and a photocoupler that notifies the detection result of CID interruption are provided separately. , Manufacturing costs can be kept low.

  The microcomputer 2 discriminates the occurrence of overcharge and the occurrence of CID interruption based on the detection signal input from the photocoupler PC and the availability of communication with the monitoring IC 21, and the battery block 10 and the battery monitoring device 20. Alternatively, a failure of the microcomputer 2 itself can be determined.

  Here, with reference to FIGS. 3 to 5, the state of the battery monitoring device 20 and the microcomputer 2 when the CID interruption occurs, the state of the battery monitoring device 20 and the microcomputer 2 when the overcharge occurs, A method for discriminating between charging and CID interruption and a method for judging failure will be described.

  FIG. 3 is an explanatory diagram illustrating states of the battery monitoring device 20 and the microcomputer 2 when the CID interruption according to the embodiment occurs. FIG. 4 is an explanatory diagram illustrating states of the battery monitoring device 20 and the microcomputer 2 when overcharge occurs according to the embodiment. FIG. 5 is an explanatory diagram of a determination method and a failure determination method between overcharge and CID interruption by the microcomputer 2 according to the embodiment.

  The battery voltage shown in FIGS. 3 and 4 is the voltage of the battery block 10, the connection of the fuse state is a state where the fuse F is not blown, and the fuse state is cut when the fuse F is blown It is in a state of being.

  3 and 4 is the voltage at the connection point between the fuse F and the resistor R8, and the capacitor voltage is the voltage of the capacitor C2 of the CID cutoff detection unit 23. Moreover, the 1st threshold value shown in FIG. 3 and FIG. 4 is a threshold voltage for overcharge detection. Further, the second threshold shown in FIG. 3 is a threshold voltage for detecting CID interruption.

  3 and FIG. 4 is a state where the photocoupler PC is outputting a detection signal to the microcomputer 2, and the photocoupler state is OFF when the photocoupler PC is outputting a detection signal to the microcomputer 2. The detection signal is not output.

  3 and 4 indicates that the microcomputer 2 cannot receive a predetermined signal from the monitoring IC 21, and that the microcomputer 2 can communicate with the monitoring IC from the monitoring IC 21. It is in the state which can receive the signal.

  As shown in FIG. 3, for example, when CID interruption occurs at time t11, the battery voltage rapidly increases. Along with this, the power supply voltage in the substrate also rises and exceeds the first threshold value at time t12. Thereby, the photocoupler PC is turned ON at time t12 because the overcharge detection unit 22 detects overcharge.

  Thereafter, when the battery voltage further rises and reaches the breakdown voltage of the Zener diodes D1 and D2 included in the fuse blowing circuit 25, a large current flows through the fuse F, the fuse F is cut, and the battery voltage and the power supply voltage in the substrate are Descent suddenly.

  As a result, when the power supply voltage in the substrate falls below the first threshold, the photocoupler PC changes from ON to OFF, and when the power supply voltage in the substrate drops below the second threshold, the CID interruption detection unit 23 Since the occurrence of CID blocking is detected, it is switched from OFF to ON at time t14.

  Thereafter, since the power supply voltage in the substrate decreases, the LDO 45 of the CID cutoff detection unit 23 cannot output a constant voltage. However, since the capacitor C2 is charged, the photocoupler PC is turned ON by discharging the capacitor C2. maintain. Then, when the voltage of the capacitor C2 falls below the minimum voltage necessary for outputting the detection signal at time t15, the photocoupler PC is turned from ON to OFF.

  Here, the microcomputer 2 can communicate with the monitoring IC 21 until the time t14 because the monitoring IC 21 can operate using the power supply voltage in the substrate as power. However, after time t14, the microcomputer 2 cannot operate with the monitoring IC 21 as the power supply voltage in the substrate decreases, and communication with the monitoring IC 21 becomes impossible.

  As shown in FIG. 4, for example, when the battery voltage increases due to overcharging of the battery block 10, and the power supply voltage in the substrate increases with this and exceeds the first threshold at time t <b> 10, overcharging occurs. Since the detection unit 22 detects overcharge, the photocoupler PC is turned from OFF to ON.

  Here, in overcharging, the power supply voltage in the substrate does not rise as much as when CID interruption occurs, so the fuse F is not cut. For this reason, the power supply voltage in the substrate is continuously supplied to the LDO 45 of the CID cutoff detection unit 23, and the capacitor C2 maintains the charged state.

  Further, the power supply voltage in the substrate is continuously supplied to the monitoring IC 21 as well. For this reason, the monitoring IC 21 can continue the operation. Therefore, the microcomputer 2 does not become unable to communicate with the monitoring IC 21 when overcharging occurs.

  The microcomputer 2 uses the difference in the state of the battery monitoring device 20 and the microcomputer 2 that is different between the case where the CID interruption as described above occurs and the case where the overcharge occurs, to distinguish between overcharge and CID interruption. Perform failure determination.

  For example, as shown in FIG. 5, the microcomputer 2 determines that the battery monitoring device 20 and the microcomputer 2 itself are normal when the photocoupler PC is in the OFF state and can communicate with the monitoring IC 21. Further, the microcomputer 2 determines that the CID interruption has occurred when the state of the photocoupler PC is ON and communication with the monitoring IC 21 is impossible. In such a case, the microcomputer 2 determines that the battery block 10 has failed.

  Further, the microcomputer 2 determines that an overcharge has occurred when the state of the photocoupler PC is ON and communication with the monitoring IC 21 is possible. In such a case, for example, the microcomputer 2 performs charge control for suppressing charging of the battery block 10. Further, the microcomputer 2 determines that the battery monitoring device 20 or the microcomputer 2 is faulty when the state of the photocoupler PC is OFF and communication with the monitoring IC 21 is impossible.

  As described above, the microcomputer 2 discriminates between occurrence of overcharge and occurrence of CID interruption based on the detection signal (the state of the photocoupler PC) input from the photocoupler PC and the availability of communication with the monitoring IC 21. can do.

  Further, the microcomputer 2 has a failure of the battery block 10, the battery monitoring device 20, or the microcomputer 2 itself based on the detection signal (the state of the photocoupler PC) input from the photocoupler PC and the availability of communication with the monitoring IC 21. Can be determined. As a result, according to the battery monitoring system 100, it is possible to identify a failed part with a dealer, so that the repair work can be made more efficient and the repair cost can be reduced.

  Note that the above-described method for determining the occurrence of CID interruption and the occurrence of overcharge is an example, and the microcomputer 2 can also determine the occurrence of CID interruption and the occurrence of overcharge by other methods. As shown in FIG. 3, when CID interruption | blocking generate | occur | produces, after the power supply voltage in a board | substrate exceeds 1st threshold value, it will fall below 2nd threshold value smaller than 1st threshold value. On the other hand, as shown in FIG. 4, when overcharge occurs, the power supply voltage in the substrate continues to be in the state after exceeding the first threshold value.

  Therefore, the microcomputer 2 detects that the battery monitoring device 20 detects that the power supply voltage in the substrate has exceeded the first threshold and then falls below the second threshold smaller than the first threshold. , It is determined that CID blocking has occurred. The microcomputer 2 determines that overcharge has occurred when the power supply voltage of the substrate continues to exceed the first threshold. Thereby, the microcomputer 2 can discriminate | determine exactly generation | occurrence | production of CID interruption | blocking and generation | occurrence | production of overcharge.

  The microcomputer 2 can make such a determination based on the state of the photocoupler PC. For example, as shown in FIG. 3, the photocoupler PC is turned ON during a period when the power supply voltage in the substrate is above the first threshold and below the second threshold.

  Then, as shown in FIG. 3, when the CID interruption occurs, the photocoupler PC is turned on, then turned off, and then turned on. Further, as shown in FIG. 4, when overcharge occurs, the photocoupler PC continues to be turned on after being turned on.

  For this reason, the microcomputer 2 can determine that the CID interruption has occurred when the battery monitoring device 20 notifies that the photocoupler PC is turned on and then turned off and then turned on. The microcomputer 2 determines that an overcharge has occurred when the battery monitoring device 20 notifies that the photocoupler PC is turned on after the photocoupler PC is turned on.

  Thus, the microcomputer 2 can determine the occurrence of CID interruption and the occurrence of overcharge with a simple configuration without determining whether communication with the monitoring IC 21 is possible. Thereby, since the microcomputer 2 can determine the occurrence of CID interruption and the occurrence of overcharge only by the detection signal input via the harness connected to the photocoupler PC, the microcomputer 2 is connected to the monitoring IC 21. Since no harness is required, the cost can be reduced.

  Note that the microcomputer 2 is turned off after the photocoupler PC is turned on, turned on again, and when a predetermined time (for example, time t14 to time t15 shown in FIG. 3) has elapsed. It can also be determined that CID blocking has occurred when it is turned off. Thereby, the microcomputer 2 can detect the occurrence of CID interruption more accurately.

  Returning to FIG. 2, the failure diagnosis of the CID interruption detection unit 23 and the overcharge detection unit 22 will be described. The microcomputer 2 outputs a diagnosis request to the monitoring IC 21 when performing failure diagnosis of the CID interruption detection unit 23.

  The monitoring IC 21 functions as a processing unit that causes the microcomputer 2 to diagnose a failure of the CID interruption detection unit 23 when an interruption request is input from the microcomputer 2. When the interruption request is input from the microcomputer 2, the monitoring IC 21 causes the CID interruption detection unit 23 to be in the same state as when CID interruption occurs. Then, the monitoring IC 21 causes the microcomputer 2 to diagnose a failure of the CID interruption detection unit 23 based on whether or not a detection signal is output from the CID interruption detection unit 23 to the microcomputer 2.

  The microcomputer 2 can diagnose the CID cutoff detection unit 23 as normal when a detection signal is output from the CID cutoff detection unit 23. Moreover, the microcomputer 2 can diagnose the CID interruption | blocking detection part 23 as a failure, when a detection signal is not output from the CID interruption | blocking detection part 23. FIG.

  Specifically, when a diagnosis request is input from the microcomputer 2, the monitoring IC 21 turns off the LDO 45 of the CID cutoff detection unit 23 and turns on the transistor Tr5. As a result, the voltage applied to the gate of the transistor Tr4 which is a PMOS transistor becomes 0V. Thereby, the CID interruption | blocking detection part 23 can be made into the same state as the case where CID interruption | blocking generate | occur | produced.

  At this time, if the transistor Tr4 is normally turned on, the photocoupler PC is turned on. If the transistor Tr4 is not turned on, the photocoupler PC is not turned on. Therefore, the microcomputer 2 diagnoses the transistor Tr4 as normal when a detection signal is input from the photocoupler PC. Further, the microcomputer 2 diagnoses the transistor Tr4 as a failure if no detection signal is input from the photocoupler PC.

  When the transistor Tr4 is normally turned on, the current flows from the capacitor C2 of the CID cutoff detection unit 23 to the light emitting diode D3 of the photocoupler PC through the transistor Tr4 and the resistor R9, and the photocoupler PC is turned on.

  Therefore, the microcomputer 2 diagnoses that the capacitance of the capacitor C2 is normal if the time during which the photocoupler PC is ON is a predetermined time (for example, the time from time t14 to time t15 shown in FIG. 3).

  Further, the microcomputer 2 diagnoses the capacity of the capacitor C2 as abnormal when the time during which the photocoupler PC is ON is not a predetermined time. Further, the microcomputer 2 diagnoses the LDO 45 as a failure when the photocoupler PC is not turned off after the photocoupler PC is turned on. As described above, the microcomputer 2 can perform not only the operation of the CID cutoff detection unit 23 but also the fault diagnosis of the circuit elements included in the CID cutoff detection unit 23.

  In addition, when performing failure diagnosis of the overcharge detection unit 22, the microcomputer 2 acquires the voltage of each battery cell 11 from the monitoring IC 21 and calculates the voltage of the battery block 10 based on the voltage of each battery cell 11.

  Further, the microcomputer 2 determines the non-inverting input terminal (+ of the comparator 33) based on the calculated voltage of the battery block 10, the resistances R1 and R2 of the voltage dividing circuit 24, and the resistance R4 of the overcharge detection unit 22. Terminal) is calculated.

  Then, the microcomputer 2 sets the threshold value so that the threshold voltage input to the inverting input terminal (− terminal) of the comparator 33 is slightly higher than the voltage input to the non-inverting input terminal (+ terminal) of the comparator 33. A control signal for adjusting the voltage is output to the threshold adjustment unit 35.

  At this time, the overcharge detection unit 22 does not output a detection signal to the microcomputer 2 if there is no failure. For this reason, when the detection signal is input from the overcharge detection unit 22 at this time, the microcomputer 2 diagnoses the overcharge detection unit 22 as a failure.

  Furthermore, the microcomputer 2 puts the threshold voltage input to the inverting input terminal (− terminal) of the comparator 33 a little lower than the voltage input to the non-inverting input terminal (+ terminal) of the comparator 33. Then, a control signal for adjusting the threshold voltage is output to the threshold adjustment unit 35 so that a pseudo overvoltage state is established.

  At this time, the overcharge detection unit 22 outputs a detection signal to the microcomputer 2 if there is no failure. For this reason, the microcomputer 2 determines that the overcharge detection unit 22 is out of order when no detection signal is input from the overcharge detection unit 22 at this time.

  Further, the microcomputer 2 outputs a control signal for adjusting the threshold voltage so as to gradually lower the threshold voltage from a threshold voltage slightly higher than the voltage input to the non-inverting input terminal (+ terminal) of the calculated comparator 33. Output to the adjustment unit 35.

  Then, the microcomputer 2 acquires the threshold voltage at the time when the detection signal is input from the overcharge detection unit 22 from the threshold adjustment unit 35, and outputs the acquired voltage to the non-inverting input terminal (+ terminal) of the comparator 33 calculated. When the voltage is equal to the input voltage, the voltage dividing circuit 24 is diagnosed as normal.

  Further, the microcomputer 2 acquires the threshold voltage at the time when the detection signal is input from the overcharge detection unit 22 from the threshold adjustment unit 35, and outputs the acquired voltage to the non-inverting input terminal (+ terminal) of the comparator 33 calculated. When the voltage is not equal to the input voltage, the voltage dividing circuit 24 is diagnosed as abnormal.

  That is, the microcomputer 2 calculates the voltage input to the non-inverting input terminal (+ terminal) of the comparator 33 and the voltage actually input to the non-inverting input terminal (+ terminal) of the comparator 33. In this case, the voltage dividing circuit 24 is diagnosed as normal, and if not equal, it is diagnosed as abnormal.

  As described above, the microcomputer 2 adjusts the threshold voltage input to the non-inverting input terminal (+ terminal) of the comparator 33 by the threshold adjustment unit 35, and based on the detection signal input from the overcharge detection unit 22. Failure diagnosis of the overcharge detection unit 22 and the voltage dividing circuit 24 can be performed.

  Next, processing executed by the microcomputer 2 according to the embodiment will be described with reference to FIGS. 6-8 is a flowchart which shows the process which the microcomputer 2 which concerns on embodiment performs.

  FIG. 6 shows processing executed when the microcomputer 2 determines the state of the battery block 10 and the battery monitoring device 20 based on the state of the photocoupler PC and whether communication with the monitoring IC 21 is possible.

  FIG. 7 shows processing executed when the microcomputer 2 determines the state of the battery block 10 based on the state of the photocoupler PC. Further, FIG. 8 shows processing executed when the microcomputer 2 performs failure diagnosis of the CID interruption detection unit 23.

  As shown in FIG. 6, when the microcomputer 2 determines the state of the battery block 10 and the battery monitoring device 20 based on the state of the photocoupler PC and whether communication with the monitoring IC 21 is possible, first, the photocoupler PC is turned off. Whether or not (step S101).

  When the microcomputer 2 determines that the photocoupler PC is OFF (step S101, Yes), the microcomputer 2 determines whether or not communication with the monitoring IC 21 is possible (step S102). And when it determines with the microcomputer 2 being communicable with the monitoring IC21 (step S102, Yes), it determines with the battery block 10 and the battery monitoring apparatus 20 being normal (step S104), and complete | finishes a process.

  If the microcomputer 2 determines that communication with the monitoring IC 21 is not possible (No at Step S102), it determines that the battery monitoring device 20 or the microcomputer 2 is out of order (Step S105) and ends the process.

  If the microcomputer 2 determines that the photocoupler PC is not OFF (No at Step S101), the microcomputer 2 determines whether communication with the monitoring IC 21 is possible (Step S103). And when it determines with the microcomputer 2 being communicable with the monitoring IC21 (step S103, Yes), it determines with the battery block 10 being overcharged (step S106), and complete | finishes a process.

  If the microcomputer 2 determines that communication with the monitoring IC 21 is not possible (step S103, No), the microcomputer 2 determines that CID interruption has occurred, determines that the battery block 10 is faulty (step S107), and ends the process. . The microcomputer 2 repeatedly executes the processing shown in FIG. 6 at a predetermined cycle.

  Further, when determining the state of the battery block 10 based on the state of the photocoupler PC, the microcomputer 2 first determines whether or not the photocoupler PC is turned on as shown in FIG. 7 (step S201). ).

  If the microcomputer 2 determines that the photocoupler PC is not turned on (No in step S201), the microcomputer 2 ends the process. If the microcomputer 2 determines that the photocoupler PC is turned on (Yes in step S201), the microcomputer 2 then determines whether the photocoupler PC is turned off during the first predetermined time (step S202). ).

  The first predetermined time is a predetermined time corresponding to t14-t12 in FIG. That is, if CID interruption has occurred, the photocoupler PC is turned off during the first predetermined time, but if overcharged, the photocoupler PC is not turned off even after the first predetermined time has elapsed.

  If the microcomputer 2 determines that the photocoupler PC has not been turned off even after the first predetermined time has elapsed (step S202, No), the microcomputer 2 determines that the battery block 10 is overcharged (step S206). The process ends. If the microcomputer 2 determines that the photocoupler PC has been turned off during the first predetermined time (step S202, Yes), then, whether or not the photocoupler PC has been turned on within the second predetermined time. Is determined (step S203). The second predetermined time is a predetermined time corresponding to t14-t13 in FIG.

  If the microcomputer 2 determines that the photocoupler PC is not turned on even after the second predetermined time has elapsed (No at Step S203), the microcomputer 2 determines that the overcharge has been resolved (Step S205). Exit. If the microcomputer 2 determines that the photocoupler PC is turned on within the second predetermined time (step S203, Yes), the microcomputer 2 determines that CID interruption has occurred (step S204), and ends the process. The microcomputer 2 repeatedly executes the process shown in FIG. 7 at a predetermined cycle.

  Further, when performing failure diagnosis of the CID interruption detection unit 23, the microcomputer 2 first outputs a diagnosis request to the monitoring IC 21 as shown in FIG. 8 (step S301), and then at the time when the third predetermined time has elapsed. It is determined whether or not the photocoupler PC is ON (step S302). The third predetermined time is a predetermined time corresponding to the time from when the diagnosis request is output until the photocoupler PC is turned on if it is normal.

  If the microcomputer 2 determines that the photocoupler PC is not ON (step S302, No), it determines that the transistor Tr4, which is the PMOS transistor of the CID cutoff detection unit 23, is abnormal (step S309), and performs the processing. finish.

  If the microcomputer 2 determines that the photocoupler PC is turned on (Yes in step S302), the microcomputer 2 diagnoses that the transistor Tr4 which is the PMOS transistor of the CID cutoff detection unit 23 is normal (step S303).

  Thereafter, the microcomputer 2 determines whether or not the photocoupler PC is turned off during the fourth predetermined time (step S304). The fourth predetermined time is a predetermined time larger than the time corresponding to t15-t14 in FIG. If the microcomputer 2 determines that the photocoupler PC has not been turned off even after the fourth predetermined time has elapsed (No at Step S304), the microcomputer 2 diagnoses the LDO 45 of the CID cutoff detection unit 23 as abnormal (Step S304). S308), the process is terminated.

  If the microcomputer 2 determines that the photocoupler PC has been turned OFF during the fourth predetermined time (step S304, Yes), the microcomputer 2 determines whether the ON time of the photocoupler PC has been the fifth predetermined time. (Step S305). The fifth predetermined time is a time having a predetermined width around the ON time (t15-t14) in the normal case.

  When the microcomputer 2 determines that the ON time of the photocoupler PC is not the fifth predetermined time (No at Step S305), the microcomputer 2 diagnoses the capacitor C2 of the CID cutoff detection unit 23 as a capacity abnormality (Step S307). The process ends.

  If the microcomputer 2 determines that the ON time of the photocoupler PC is the fifth predetermined time (Yes in step S305), the microcomputer 2 diagnoses that the capacitor C2 of the CID cutoff detection unit 23 has a normal capacity (step S306). The process ends.

  The configuration of the battery monitoring device 20 shown in FIG. 2 is an example, and various modifications are possible. Next, a battery monitoring device 20a according to a modification will be described with reference to FIGS. FIG. 9 is an explanatory diagram illustrating an example of a configuration of a battery monitoring device 20a according to a modification of the embodiment.

  FIG. 10 is an explanatory diagram of a determination method and a failure determination method between overcharge and CID interruption by the microcomputer 2a according to the modification of the embodiment. Here, among the components shown in FIG. 9, the same components as those shown in FIG. 2 are denoted by the same reference numerals as those in FIG.

  As shown in FIG. 9, the battery monitoring device 20 a according to the modification has the battery shown in FIG. 2 in that the CID cutoff detection unit 23 (see FIG. 2) and the battery voltage measurement unit 5 are provided. Different from the monitoring device 20.

  The battery voltage measurement unit 5 measures the voltage of the battery block 10 and outputs the measurement result to the microcomputer 2a. The battery voltage measuring unit 5 is provided on a substrate different from the substrate on which the monitoring IC 21 and the overcharge detection unit 22 are provided.

  Thereby, according to the battery monitoring apparatus 20a, since the CID interruption | blocking detection part 23 (refer FIG. 2) is not provided, size reduction of the board | substrate with which the monitoring IC21 and the overcharge detection part 22 are provided can be achieved. Then, as shown in FIG. 10, the microcomputer 2 a according to the modification performs discrimination between overcharge and CID interruption and failure determination based on the measured value of the battery voltage and the availability of communication with the monitoring IC 21.

  In addition, the normality of the measured value of the battery voltage shown in FIG. 10 means that the voltage of the battery block 10 is within a normal voltage range that is not overcharge / discharge. Moreover, the abnormality of the measured value of the battery voltage shown in FIG. 10 means that the voltage of the battery block 10 is outside the normal voltage range that is not overcharge / discharge.

  If the measured value of the battery voltage is normal and communication with the monitoring IC 21 is possible, the microcomputer 2a determines that the battery monitoring device 20 and the microcomputer 2a themselves are normal. Further, the microcomputer 2a determines that the CID interruption has occurred when the measured value of the battery voltage is abnormal and communication with the monitoring IC 21 is impossible. In such a case, the microcomputer 2a determines that the battery block 10 has failed.

  The microcomputer 2a determines that overcharge / discharge has occurred when the measured value of the battery voltage is abnormal and communication with the monitoring IC 21 is possible. The microcomputer 2 determines that the battery monitoring device 20 or the microcomputer 2a itself is out of order when the measured value of the battery voltage is normal and communication with the monitoring IC 21 is impossible.

  Thus, the microcomputer 2a can determine overcharge and CID interruption based on the measured value of the battery voltage and the availability of communication with the monitoring IC 21. Moreover, since the microcomputer 2a can determine the failure of the battery block 10, the battery monitoring device 20a, or the microcomputer 2a itself, it is possible to identify the failure part at the dealer, and to improve the efficiency of repair work. Cost can be reduced.

  In the above-described embodiment, the case where the battery monitoring system according to the embodiment is mounted on a vehicle has been described as an example. However, in the present embodiment, other secondary batteries such as a secondary battery for home use are used. It can be applied to any battery monitoring system to be monitored.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

DESCRIPTION OF SYMBOLS 100 Battery monitoring system 1 Battery pack 10 Battery block 11 Battery cell 2, 2a Microcomputer 20, 20a Battery monitoring apparatus 21 Monitoring IC
22 Overcharge detection unit 23 CID interruption detection unit 24 Voltage divider circuit 25 Fuse blown circuit 5 Battery voltage measurement unit

Claims (5)

By a battery monitoring device that detects that a voltage higher than a predetermined voltage is applied to the current path due to occurrence of CID interruption that interrupts the current path of the battery by CID (Current Interrupt Device), and grounds the current path, After detecting that the voltage of the current path has exceeded the first threshold value, and detecting that the voltage has fallen below a second threshold value smaller than the first threshold value, detecting the occurrence of the CID interruption. Control device characterized. Notifying the control device by turning on a photocoupler that the voltage of the current path is equal to or higher than the first threshold and that the voltage of the current path is equal to or lower than the second threshold. 2. The control according to claim 1, wherein the occurrence of the CID interruption is detected when a battery monitoring device notifies that the photocoupler is turned on after being turned on and then turned on. 3. apparatus. 3. The control device according to claim 1, wherein occurrence of overcharge in the battery is detected when a state where the voltage of the current path exceeds the first threshold value continues. A battery monitoring device and a control device for monitoring the state of the battery,
The battery monitoring device includes:
Detecting the voltage of the current path of the battery and detecting that a voltage higher than a predetermined voltage is applied to the current path due to occurrence of CID interruption that interrupts the current path of the battery by CID (Current Interrupt Device) Grounding the current path;
The control device includes:
When the battery monitoring device detects that the voltage of the current path has exceeded the first threshold value, and then detects that the voltage has fallen below a second threshold value that is smaller than the first threshold value, the occurrence of the CID interruption A battery monitoring system characterized by detecting By a battery monitoring device that detects that a voltage higher than a predetermined voltage is applied to the current path due to occurrence of CID interruption that interrupts the current path of the battery by CID (Current Interrupt Device), and grounds the current path, After detecting that the voltage of the current path has exceeded the first threshold, when detecting that the voltage has fallen below the second threshold smaller than the first threshold, detecting the occurrence of the CID interruption A battery monitoring method comprising:

Images