WO2020125375A1 - Circuit de protection de batterie, plaque de protection de batterie, batterie et dispositif terminal - Google Patents

Circuit de protection de batterie, plaque de protection de batterie, batterie et dispositif terminal Download PDF

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Publication number
WO2020125375A1
WO2020125375A1 PCT/CN2019/121914 CN2019121914W WO2020125375A1 WO 2020125375 A1 WO2020125375 A1 WO 2020125375A1 CN 2019121914 W CN2019121914 W CN 2019121914W WO 2020125375 A1 WO2020125375 A1 WO 2020125375A1
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WO
WIPO (PCT)
Prior art keywords
terminal
detection
unit
fault isolation
electrically connected
Prior art date
Application number
PCT/CN2019/121914
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English (en)
Chinese (zh)
Inventor
刘新宇
张霞玲
安艳宾
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201910336826.8A external-priority patent/CN111355222B/zh
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP19898904.8A priority Critical patent/EP3902078B1/fr
Priority to KR1020217023126A priority patent/KR102666759B1/ko
Priority to US17/416,519 priority patent/US11962143B2/en
Publication of WO2020125375A1 publication Critical patent/WO2020125375A1/fr

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/18—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for batteries; for accumulators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries

Definitions

  • the present application relates to the field of circuits, and more specifically, to battery protection circuits, battery protection boards, batteries, and terminal equipment.
  • a battery protection board is generally configured in the lithium battery.
  • the battery protection board can achieve overvoltage and undervoltage on the battery. Voltage, charge overcurrent, discharge overcurrent protection.
  • the current battery protection board can realize the double protection of the battery. After the first protection fails, the second protection can also ensure the safety of the battery.
  • the first protection and the second protection respectively have their corresponding detection chips, switching elements and current detection elements. In the first protection, the detection by the first detection chip The voltage across the first current detection element realizes the first protection, and in the second protection, the voltage across the second current detection element detected by the second detection chip realizes the second protection.
  • the above battery protection board has more losses, which causes more battery losses and generates more heat.
  • the charging speed is getting faster and faster, how to reduce the battery In order to reduce costs, it is an urgent problem to be solved.
  • the present application provides a battery protection circuit, a battery protection board and a battery, which can effectively reduce the loss of the battery.
  • a battery protection circuit in a first aspect, includes:
  • the first output terminal and the second output terminal are used for electrical connection with the power supply or load
  • the unit, the second switching unit, the battery cell, and the load or the power supply form a loop to charge or discharge the battery cell, and the current detection element includes two terminals;
  • the first detection unit includes a power supply terminal, a control terminal, and two detection terminals.
  • the power supply terminal of the first detection unit is electrically connected to the first output terminal, and the two detection terminals of the first detection unit are respectively connected to the The two terminals of the current detection element are electrically connected, and the control terminal of the first detection unit is electrically connected to the terminal of the first switch unit;
  • the second detection unit includes a power supply terminal, a control terminal and two detection terminals.
  • the power supply terminal of the second detection unit is electrically connected to the first output terminal, and the two detection terminals of the second detection unit are respectively connected to the The two terminals of the current detection element are electrically connected, and the control terminal of the second detection unit is electrically connected to the terminal of the second switching unit.
  • the battery protection circuit includes a first detection unit, a second detection unit, and a current detection element, a first switching unit, and a second switching unit used in series with the battery cell, so that The current detection element, the first switching unit, the second switching unit, the cell and the load or power supply form a loop, the first detection unit corresponds to the first switching unit, the second detection unit corresponds to the second switching unit, and each detection unit is based on the detection The voltage across the same current detection element controls the on or off of the corresponding switch unit to control the on or off of the loop.
  • the number of current detection elements in the battery protection circuit can be effectively reduced to reduce battery protection
  • the battery protection circuit further includes:
  • the first fault isolation unit is electrically connected to the first detection unit and the current detection element, respectively, so that in the event of a short circuit in the circuit electrically connected to the first terminal of the first fault isolation unit, the No short circuit occurs at both ends of the current detection element, wherein the first terminal of the first fault isolation unit is electrically connected to one detection terminal of the first detection unit.
  • the battery protection circuit provided by the embodiment of the present application, by providing a first fault isolation unit electrically connected to the first detection unit and the current detection element, in some cases, for example, the first detection unit is used to detect current When a short circuit occurs between two detection terminals of the voltage across the detection element, or two of the first filter capacitors connected in parallel between the two detection terminals of the first detection unit for detecting the voltage of the current detection element
  • the first fault isolation unit due to the provision of the first fault isolation unit, current can still flow through the current detection element, and a voltage is formed at both ends of the current detection element, which can be controlled by detecting the voltage across the current detection element
  • the conduction or disconnection of the loop will not affect the overcurrent protection of the second detection unit and the second switching unit, and will not burn out the first detection unit or the first filter capacitor.
  • the first fault isolation unit includes: a first fault isolation element, the first fault isolation element includes a first terminal and a second terminal, and the first terminal of the first fault isolation element is the first A first terminal of a fault isolation unit, and the two detection terminals of the first detection unit include a first detection terminal and a second detection terminal, and the two terminals of the current detection element include a first terminal and a second terminal ,among them,
  • the first terminal of the first fault isolation element is electrically connected to the first detection terminal of the first detection unit, and the second terminal of the first fault isolation element is electrically connected to the first terminal of the current detection element, The second terminal of the current detection element is electrically connected to the second detection terminal of the first detection unit.
  • the first fault isolation element is a resistor.
  • the first fault isolation unit includes: a first fault isolation element and a second fault isolation element, the first fault isolation element includes a first terminal and a second terminal, and the second fault isolation element includes a first A terminal and a second terminal, the first terminal of the first fault isolation element or the first terminal of the second fault isolation element is the first terminal of the first fault isolation unit, and the first detection
  • the two detection terminals of the unit include a first detection terminal and a second detection terminal, and the two terminals of the current detection element include a first terminal and a second terminal, wherein,
  • the first terminal of the first fault isolation element is electrically connected to the first detection terminal of the first detection unit, and the second terminal of the first fault isolation element is electrically connected to the first terminal of the current detection element,
  • the first terminal of the second fault isolation element is electrically connected to the second detection terminal of the first detection unit, and the second terminal of the second fault isolation element is electrically connected to the second terminal of the current detection element.
  • the first fault isolation element and/or the second fault isolation element is a resistor.
  • the absolute value of the difference between the impedance of the circuit formed by the first fault isolation unit and the current detection element in parallel and the resistance value of the current detection element is less than or equal to a preset value.
  • the absolute value of the difference between the equivalent impedance of the circuit formed by the first fault isolation unit and the current detection element in parallel and the resistance value of the current detection element is less than or equal to the preset value Value, before and after certain faults occur, for example, before and after a short circuit occurs between the terminals for detecting the voltage across the current detection element in the first detection unit, or for detecting current detection in parallel with the first detection unit
  • the difference between the current threshold of charging overcurrent through the battery cell or the current through the discharging cell is small, so that the reliability of the overcurrent protection can be improved.
  • the battery protection circuit further includes:
  • the second fault isolation unit is electrically connected to the second detection unit and the current detection element, respectively, so that in the event of a short circuit in the circuit electrically connected to the first terminal of the second fault isolation unit, the No short circuit occurs at both ends of the current detection element, wherein the first terminal of the second fault isolation unit is electrically connected to one detection terminal of the second detection unit.
  • the battery protection circuit provided by the embodiment of the present application, by providing a second fault isolation unit electrically connected to the second detection unit and the current detection element, in some cases, for example, the second detection unit is used to detect current When a short circuit occurs between the two detection terminals of the voltage across the detection element, or when a short circuit occurs between the two terminals of the second filter capacitor connected in parallel between the two detection terminals, the second The fault isolation unit can make the current pass through the second fault isolation unit and the current detection element respectively, and the second fault isolation unit and the current detection element form a parallel relationship, so that there is a voltage across the current detection element, by detecting the voltage across the current detection element The conduction or disconnection of the control loop will not affect the overcurrent protection of the first detection unit and the first switching unit, and will not burn out the second detection unit or the second filter capacitor.
  • the second fault isolation unit includes: a third fault isolation element, the third fault isolation element includes a first terminal and a second terminal, and the first terminal of the third fault isolation element is the first The first terminal of the second fault isolation unit, and the two detection terminals of the second detection unit include a first detection terminal and a second detection terminal, and the two terminals of the current detection element include a first terminal and a second terminal ,among them,
  • the first terminal of the third fault isolation element is electrically connected to the first detection terminal of the second detection unit, and the second terminal of the third fault isolation element is electrically connected to the first terminal of the current detection element, The second terminal of the current detection element is electrically connected to the second detection terminal of the second detection unit.
  • the third fault isolation element is a resistor.
  • the second fault isolation unit includes: a third fault isolation element and a fourth fault isolation element, the third fault isolation element includes a first terminal and a second terminal, and the fourth fault isolation element includes a first A terminal and a second terminal, the first terminal of the third fault isolation element or the first terminal of the fourth fault isolation element is the first terminal of the second fault isolation unit, and the second detection
  • the two detection terminals of the unit include a first detection terminal and a second detection terminal, and the two terminals of the current detection element include a first terminal and a second terminal, wherein,
  • the first terminal of the third fault isolation element is electrically connected to the first detection terminal of the second detection unit, and the second terminal of the third fault isolation element is electrically connected to the first terminal of the current detection element,
  • the first terminal of the fourth fault isolation element is electrically connected to the second detection terminal of the second detection unit, and the second terminal of the fourth fault isolation element is electrically connected to the second terminal of the current detection element.
  • the third fault isolation element and/or the fourth fault isolation element is a resistor.
  • the absolute value of the difference between the equivalent impedance of the circuit formed by the second fault isolation unit and the current detection element in parallel and the resistance value of the current detection element is less than or equal to a preset value.
  • the battery protection circuit further includes:
  • the first filter capacitor is connected in parallel between the two detection terminals of the first detection unit.
  • the interference noise between the detected signal at both ends of the current detection element and the two detection terminals of the first detection unit can be effectively reduced, Improve the reliability of the circuit.
  • the battery protection circuit further includes:
  • the second filter capacitor is connected in parallel between the two detection terminals of the second detection unit.
  • the interference noise between the detected signal at both ends of the current detection element and the two detection terminals of the second detection unit can be effectively reduced to Improve the reliability of the circuit.
  • control terminal of the first detection unit includes a discharge control terminal and a charge control terminal
  • the first switch unit includes a first discharge switching element and a first charge switching element
  • the first discharge switching element includes a first A terminal
  • the first terminal of the first discharge switching element and the discharge control terminal of the first detection unit are electrically connected
  • the first charging switching element includes a first terminal, the first of the first charging switching element The terminal is electrically connected to the charging control terminal of the first detection unit;
  • the control terminal of the second detection unit includes a discharge control terminal and a charge control terminal.
  • the second switch unit includes a second discharge switch element and a second charge switch element.
  • the second discharge switch element includes a first terminal. The first terminal of the second discharge switch element and the discharge control terminal of the second detection unit are electrically connected, the second charge switch element includes a first terminal, the first terminal of the second charge switch element and the The charging control terminal of the second detection unit is electrically connected.
  • a battery protection circuit includes:
  • the unit, the cell and the load or the power supply form a loop to charge or discharge the cell, and the first switch unit and the second switch unit are used to control the conduction of the loop On or off;
  • the first detection unit is used to detect the voltage across the battery detection element, and if the voltage across the battery detection element is greater than the preset threshold of the overcurrent detection voltage of the first detection unit, A switch unit outputs a control signal to disconnect the first switch unit;
  • a second detection unit configured to detect the voltage across the battery detection element, and if the voltage across the battery detection element is greater than the preset threshold of the overcurrent detection voltage of the second detection unit, The second switch unit outputs a control signal to disconnect the second switch unit;
  • the preset threshold value of the overcurrent detection voltage of the first detection unit is different from the preset threshold value of the overcurrent detection voltage of the second detection unit.
  • the battery protection circuit includes a first detection unit, a second detection unit, and a current detection element, a first switching unit, and a second switching unit used in series with the battery cell, so that The current detection element, the first switching unit, the second switching unit, the cell and the load or power supply form a loop, the first detection unit corresponds to the first switching unit, the second detection unit corresponds to the second switching unit, and each detection unit is based on the detection The voltage across the same current detection element controls the on or off of the corresponding switch unit to control the on or off of the loop.
  • the number of current detection elements in the battery protection circuit can be effectively reduced to reduce battery protection
  • the battery protection circuit further includes:
  • the first fault isolation unit is electrically connected to the first detection unit and the current detection element, respectively.
  • the current detection element shunts the current passing through the cell so that the two ends of the current detection element are not short-circuited, wherein the first terminal of the first fault isolation unit and one of the first detection unit detect The terminals are electrically connected.
  • the battery protection circuit provided by the embodiment of the present application, by providing a first fault isolation unit electrically connected to the first detection unit and the current detection element, in some cases, for example, the first detection unit is used to detect current When a short circuit occurs between two detection terminals of the voltage across the detection element, or two of the first filter capacitors connected in parallel between the two detection terminals of the first detection unit for detecting the voltage of the current detection element
  • the current can be passed through the first fault isolation unit and the current detection element respectively, forming a voltage across the current detection element, by detecting the current detection element two
  • the voltage at the terminal controls the conduction or disconnection of the loop, which will not affect the overcurrent protection of the second detection unit and the second switching unit, and will not burn out the first detection unit or the first filter capacitor.
  • the first fault isolation unit includes: a first fault isolation element, the first fault isolation element includes a first terminal and a second terminal, and the first terminal of the first fault isolation element is the first A first terminal of a fault isolation unit, and the first detection unit includes a first detection terminal and a second detection terminal, and the current detection element includes a first terminal and a second terminal, wherein,
  • the first terminal of the first fault isolation element is electrically connected to the first detection terminal of the first detection unit, and the second terminal of the first fault isolation element is electrically connected to the first terminal of the current detection element, The second terminal of the current detection element is electrically connected to the second detection terminal of the first detection unit.
  • the first fault isolation element is a resistor.
  • the first fault isolation unit includes: a first fault isolation element and a second fault isolation element, the first fault isolation element includes a first terminal and a second terminal, and the second fault isolation element includes a first A terminal and a second terminal, the first terminal of the first fault isolation element or the first terminal of the second fault isolation element is the first terminal of the first fault isolation unit, and the first detection The unit includes a first detection terminal and a second detection terminal, and the current detection element includes a first terminal and a second terminal, wherein,
  • the first terminal of the first fault isolation element is electrically connected to the first detection terminal of the first detection unit, and the second terminal of the first fault isolation element is electrically connected to the first terminal of the current detection element,
  • the first terminal of the second fault isolation element is electrically connected to the second detection terminal of the first detection unit, and the second terminal of the second fault isolation element is electrically connected to the second terminal of the current detection element.
  • the absolute value of the difference between the equivalent impedance of the circuit formed by the first fault isolation unit and the current detection element in parallel and the resistance value of the current detection element is less than or equal to a preset value.
  • the battery protection circuit further includes:
  • the second fault isolation unit is electrically connected to the second detection unit and the current detection element respectively, and is used to connect with all the circuits when the circuit electrically connected to the first terminal of the second fault isolation unit is short-circuited.
  • the current detection element shunts the current passing through the cell so that the two ends of the current detection element are not short-circuited, wherein the first terminal of the second fault isolation unit is detected by one of the second detection units The terminals are electrically connected.
  • the battery protection circuit provided by the embodiment of the present application, by providing a second fault isolation unit electrically connected to the second detection unit and the current detection element, in some cases, for example, the second detection unit is used to detect current When a short circuit occurs between the two detection terminals of the voltage across the detection element, or when a short circuit occurs between the two terminals of the second filter capacitor connected in parallel between the two detection terminals, the second The fault isolation unit can make the current pass through the second fault isolation unit and the current detection element respectively, and the second fault isolation unit and the current detection element form a parallel relationship, so that there is a voltage across the current detection element, by detecting the voltage across the current detection element The conduction or disconnection of the control loop will not affect the overcurrent protection of the first detection unit and the first switching unit, and will not burn out the second detection unit or the second filter capacitor.
  • the second fault isolation unit includes:
  • a third fault isolation element including a first terminal and a second terminal, the first terminal of the third fault isolation element being the first terminal of the second fault isolation unit, and, the The second detection unit includes a first detection terminal and a second detection terminal, and the current detection element includes a first terminal and a second terminal, wherein,
  • the first terminal of the third fault isolation element is electrically connected to the first detection terminal of the second detection unit, and the second terminal of the third fault isolation element is electrically connected to the first terminal of the current detection element, The second terminal of the current detection element is electrically connected to the second detection terminal of the second detection unit.
  • the second fault isolation unit includes:
  • a third fault isolation element and a fourth fault isolation element includes a first terminal and a second terminal
  • the fourth fault isolation element includes a first terminal and a second terminal
  • the third fault isolation The first terminal of the element or the first terminal of the fourth fault isolation element is the first terminal of the second fault isolation unit
  • the second detection unit includes a first detection terminal and a second detection terminal.
  • the current detection element includes a first terminal and a second terminal, wherein,
  • the first terminal of the third fault isolation element is electrically connected to the first detection terminal of the second detection unit, and the second terminal of the third fault isolation element is electrically connected to the first terminal of the current detection element,
  • the first terminal of the fourth fault isolation element is electrically connected to the second detection terminal of the second detection unit, and the second terminal of the fourth fault isolation element is electrically connected to the second terminal of the current detection element.
  • a battery protection board including the battery protection circuit in any possible implementation manner of the first aspect or the second aspect.
  • a battery including a battery cell and a battery protection board in any possible implementation manner of the third aspect, and the battery protection circuit in the battery protection board includes two input terminals, The two input terminals are electrically connected to the battery cells, respectively.
  • a terminal device includes a connector, a power supply, a load, and a battery according to the fourth aspect, wherein the connector is electrically connected to the power supply, and the power supply is electrically connected to the battery. Connected, the battery is electrically connected to the load.
  • a terminal device includes: a connector, a power supply, a load, and a battery.
  • the connector is electrically connected to the power supply.
  • the battery includes a battery protection circuit board and a battery cell, wherein ,
  • the battery protection board includes:
  • the unit, the cell and the load or the power supply form a loop to charge or discharge the cell, and the first switch unit and the second switch unit are used to control the conduction of the loop On or off;
  • the first detection unit is configured to detect the voltage across the battery detection element, and if the voltage across the current detection element is greater than the preset threshold of the overcurrent detection voltage of the first detection unit, A switch unit outputs a control signal to disconnect the first switch unit;
  • a second detection unit configured to detect the voltage across the battery detection element, and if the voltage across the current detection element is greater than the preset threshold of the overcurrent detection voltage of the second detection unit, The second switch unit outputs a control signal to disconnect the second switch unit;
  • the preset threshold of the overcurrent detection voltage of the first detection unit is different from the preset threshold of the overcurrent detection voltage of the second detection unit.
  • the first detection unit includes two detection terminals for detecting the voltage across the current detection unit
  • the battery protection board further includes:
  • the first fault isolation unit is electrically connected to the first detection unit and the current detection element, respectively.
  • the current detection element shunts the current passing through the cell so that the two ends of the current detection element are not short-circuited, wherein the first terminal of the first fault isolation unit and one of the first detection unit detect The terminals are electrically connected.
  • the second detection unit includes two detection terminals for detecting the voltage across the battery detection unit
  • the battery protection board further includes:
  • the second fault isolation unit is electrically connected to the second detection unit and the current detection element respectively, and is used to connect with all the circuits when the circuit electrically connected to the first terminal of the second fault isolation unit is short-circuited.
  • the current detection element shunts the current passing through the cell so that the two ends of the current detection element are not short-circuited, wherein the first terminal of the second fault isolation unit is detected by one of the second detection units The terminals are electrically connected.
  • FIG. 1 is a schematic diagram of an application scenario applicable to an embodiment of the present application.
  • FIG. 2 is a schematic structural diagram of a battery protection circuit according to an embodiment of the present application.
  • FIG. 3 is a schematic circuit diagram of a battery protection circuit according to an embodiment of the present application.
  • FIG. 4 is another schematic circuit diagram of the battery protection circuit of the embodiment of the present application.
  • FIG. 5 is another schematic structural diagram of a battery protection circuit according to an embodiment of the present application.
  • FIG 6 is another schematic circuit diagram of the battery protection circuit of the embodiment of the present application.
  • FIG 7 is another schematic circuit diagram of the battery protection circuit of the embodiment of the present application.
  • FIG. 8 is another schematic structural diagram of a battery protection circuit according to an embodiment of the present application.
  • 9 is another schematic circuit diagram of the battery protection circuit of the embodiment of the present application.
  • FIG. 10 is another schematic circuit diagram of the battery protection circuit of the embodiment of the present application.
  • FIG. 11 is another schematic structural diagram of a battery protection circuit according to an embodiment of the present application.
  • FIG. 12 is another schematic structural diagram of a battery protection circuit according to an embodiment of the present application.
  • FIG 13 is yet another schematic structural diagram of the battery protection circuit of the embodiment of the present application.
  • FIG. 1 is an application scenario applicable to the embodiment of the present application.
  • the charger 130 is electrically connected to the terminal device 110 through the cable 120.
  • the terminal device 110 includes a connector 111, a charging management chip 112, The battery 113 and the load 114, the connector 111 is electrically connected to the charge management chip 112, and the battery 113 is electrically connected to the charge management chip 112 and the load 114, respectively, wherein the battery includes a battery protection board 113-1 and a battery cell 113-2.
  • the load 114 may be a power-consuming device in the terminal device.
  • the load 114 may be various power-consuming devices such as a microphone, a camera, and a motor.
  • the charge management chip may be understood as a power source for charging the battery.
  • the current flow is: charger 130 ⁇ cable 120 ⁇ connector 111 ⁇ charge management chip 112 ⁇ battery protection board 113-1 ⁇ cell 113-2, when discharging, the current flow is: cell 113-2 ⁇ Battery protection board 113-1 ⁇ load 114.
  • the battery protection board has clear requirements on the current value, whether it is in the charging process or the discharge process, when the preset current threshold is exceeded, under normal circumstances, the battery protection board will cut off the charging circuit or the discharge circuit to avoid continuous current flow in the battery core , Overheating reaction occurs, so that the battery life, capacity and safety will have problems.
  • the charging circuit can also be understood as the circuit through which the current passes through the battery cell during the charging process
  • the discharging circuit can be understood as the circuit through which the current passes through the battery cell during the discharging process.
  • charging overcurrent the phenomenon that the current passing through the battery during charging
  • discharge current the current passing through the battery during discharging
  • the phenomenon that exceeds a preset current threshold is called discharge overcurrent.
  • the protective measures taken against charging overcurrent can be referred to as charging overcurrent protection
  • the protective measures taken against discharging overcurrent can be referred to as discharge overcurrent protection.
  • Charging overcurrent protection and discharge overcurrent protection can be collectively referred to as Overcurrent protection.
  • the battery protection board can realize the overvoltage protection, undervoltage protection and overcurrent protection of the battery (for example, lithium battery), each protection can realize the double protection of the battery, in general, the voltage of the first protection
  • the threshold or current threshold is less than the voltage or current threshold of the second protection.
  • the principle of charging overcurrent protection in overcurrent protection is the same as that of discharge overcurrent protection. Below, taking charging overcurrent protection as an example, the principle of overcurrent protection will be briefly described.
  • the battery protection board may be provided with a first re-detection unit and a second re-detection unit.
  • the charging circuit can be cut off by the first detection unit to cut off the current through the battery; if the first detection unit fails, the charging circuit cannot be disconnected in time, and the battery will continue to be charged, if it flows through the battery.
  • the current of is greater than the current threshold preset by the second detection unit, and the charging circuit can be cut off by the second detection unit to cut off the current passing through the battery cell.
  • two detection resistors may be connected in series in the charging circuit or the discharge circuit (for convenience of distinction, they are respectively denoted as a first detection resistor and a second detection resistor).
  • the first detection unit is used to detect the first One detects the voltage across the resistance
  • the second detection unit is used to detect the voltage across the second detection resistor.
  • the current through the cell can be detected by separately detecting the voltage across the two detection resistors.
  • the current of the detection resistor is also the current through the battery cell.
  • the current through the cell can be detected by the voltage detected by the detection unit to achieve overcurrent protection. If the voltage across the first detection resistor is greater than the preset threshold of the overcurrent detection voltage of the first heavy detection unit, the charging circuit or the discharge circuit is cut off by the first heavy detection unit to cut off the current passing through the cell; if the second detection The voltage across the resistor is greater than the preset threshold of the overcurrent detection voltage of the second detection unit, and the charging circuit or the discharge circuit can be cut off by the second detection unit to cut off the current passing through the cell.
  • the preset threshold of the overcurrent detection voltage of the detection unit (for example, the first heavy detection unit or the second heavy detection unit) is a fixed value, and the preset threshold and overcurrent protection may be based on the overcurrent detection voltage of the detection unit
  • the battery protection board has more losses.
  • the embodiments of the present application provide a battery protection circuit configured on the battery protection board, which helps reduce battery protection The loss of the board to reduce the cost of the battery protection board.
  • the same current detection element is provided for the first double detection unit and the second double detection unit, so that the first double detection unit and the second detection unit jointly use one current detection element to achieve overcurrent protection, by reducing The number of current detection elements achieves the purpose of reducing the loss of the battery protection board to reduce the cost of the battery protection board.
  • the battery protection circuit of the embodiment of the present application will be described in detail below with reference to FIGS. 2 to 13. It should be understood that the connection relationships of the battery protection circuits shown in FIGS. 2 to 13 are only schematic illustrations, and any functional modules (eg, first detection unit, second detection unit, first fault isolation unit, and second fault The battery protection circuits of the isolation unit, etc. are within the protection scope of the embodiments of the present application, and should not be limited to the embodiments of the present application.
  • FIG. 2 includes a battery protection circuit 200 and a battery cell 230.
  • the battery protection circuit 200 includes: a first output terminal P+, a second output terminal P-, a current detection element 211, a first switching unit 212, and a second switching unit 213.
  • the first output terminal P+ and the second output terminal P- are used for electrical connection with a power source or a load.
  • the power source may be the charge management chip 112 shown in FIG. 1, and the load may be the load 114 shown in FIG. 1.
  • the current detection element 211, the first switching unit 212, and the second switching unit 213 are used in series with the battery cell 230 between the first output terminal P+ and the second output terminal P-, so that the current detection element 211, the first switching unit 212, the second switch unit 213, the cell 230 and the load or power supply form a loop to charge or discharge the cell 230, and the first switch unit 212 and the second switch unit 213 are both used to control the conduction or disconnection of the loop .
  • the battery protection circuit 200 further includes two input terminals, respectively an input terminal B+ and an input terminal B-, which are electrically connected to both ends of the battery cell 230 respectively, forming a current detection element 211, a first switching unit 212, and a second switching unit 213.
  • the circuit may be a charging circuit or a discharging circuit.
  • the current flow is output terminal P+ ⁇ cell 230 ⁇ current detection element 211 ⁇ second switching unit 213 ⁇ first switching unit 212 ⁇ output terminal P-
  • the current flow is the positive electrode of the cell 230 ⁇ the output terminal P+ ⁇ the output terminal P- ⁇ the first switch unit 212 ⁇ the second switch unit 213 ⁇ the current detection element 211 ⁇ the negative electrode of the cell 230.
  • the first detection unit 221 and the second detection unit 222 share the current detection element 211, and both of them detect the voltage across the current detection element 211 to realize the conduction or disconnection of the loop.
  • the first detection unit 221 includes a power supply terminal (VDD terminal), a control terminal 3, and two detection terminals (detection terminal 1 and detection terminal 2), and the VDD terminal of the first detection unit 221 is electrically connected to the first output terminal P+ , Used to supply power to the first detection unit 221, so as to provide the first detection unit 221 with an operating voltage and current to ensure the normal operation of the first detection unit 221.
  • the two detection terminals of the first detection unit 221 are electrically connected to the two terminals (terminal 1 and terminal 2) of the current detection element 211, respectively, for detecting the voltage across the current detection element 211.
  • the control terminal 3 of the first detection unit 221 is electrically connected to the terminal 3 of the first switch unit 212 to control the conduction or disconnection of the first switch unit 212, thereby controlling the conduction or disconnection of the loop.
  • the second detection unit 222 includes a power supply terminal (VDD terminal), a control terminal 3, and two detection terminals (terminal 1 and terminal 2).
  • the VDD terminal of the second detection unit 222 is electrically connected to the first output terminal P+.
  • the second detection unit 222 is provided with an operating voltage and current to ensure the normal operation of the second detection unit 222.
  • the two detection terminals of the second detection unit 222 are respectively electrically connected to the two terminals (terminal 1 and terminal 2) of the current detection element 211 for detecting the voltage across the current detection element 211, and the control terminal 3 of the second detection unit 222 It is electrically connected to the terminal 3 of the second switching unit 213 to control the conduction or disconnection of the second switching unit 213, thereby controlling the conduction or disconnection of the loop.
  • the first detection unit 221 can be understood as the first re-detection unit described above, the second detection unit 222 can be understood as the second re-detection unit described above, or the first detection unit 221 can be understood as the above
  • the second detection unit and the second detection unit 222 can be understood as the first detection unit described above, and the embodiment of the present application does not make any limitation.
  • the first detection unit 221 may be used as the first re-detection unit
  • the second detection unit 222 may be used as the second re-detection unit.
  • the overcurrent detection voltage of the first detection unit 221 is preset
  • the threshold value is denoted as U 1
  • the preset threshold value of the overcurrent detection voltage across the second detection unit 222 is denoted as U 2
  • the voltage across the current detection element 211 is denoted as U 0 .
  • the first detection unit 221 is used to detect the voltage U 0 across the current detection element 211. If U 0 is greater than U 1 , the first detection unit 221 sends a control signal to the first switch unit 212 to open the first switch Unit 212, thereby opening the loop to achieve overcurrent protection.
  • the second detection unit 222 is also used to detect the voltage U 0 at both ends of the current detection element 211.
  • the first detection unit 221 fails, even if U 0 is greater than U 1 , the loop cannot be opened in time to continue charging the battery or Discharge until U 0 is greater than U 2 , and the second detection unit 222 sends a control signal to the second switch unit 213 to open the second switch unit 213, thereby opening the loop to achieve overcurrent protection.
  • the battery protection circuit includes a first detection unit, a second detection unit, and a current detection element, a first switching unit, and a second switching unit that are connected in series with the cell,
  • the first detection unit corresponds to the first switch unit
  • the second detection unit corresponds to the second switch unit
  • each detection unit According to the detected voltage across the same current detection element, the corresponding switch unit is turned on or off to control the loop on or off.
  • the number of current detection elements in the battery protection circuit can be effectively reduced to reduce the battery protection circuit Impedance, thereby reducing the loss of the battery protection board, thereby reducing costs, especially in the current smart terminal loss is increasing and charging faster and faster, it is particularly important to save the loss of the battery protection board.
  • the two detection terminals of the first detection unit 221 and the second detection unit 222 may be the VSS terminal and the IS terminal, and referring to FIG. 4, the two detection terminals of the first detection unit 221 and the second detection unit 222
  • the detection terminals can all be IS terminals.
  • the VSS terminal represents the ground point or the negative pole of the power supply
  • the IS terminal represents the current detection terminal. It should be understood that the detection terminals shown in FIGS. 3 and 4 are only schematic illustrations, and any terminal capable of detecting the voltage of the current detection element 211 may be, and is not limited herein.
  • the current detection element 211 may be a detection resistor Rs.
  • the current detection element 211 may also be an element that can measure current, such as a shunt or a Hall element.
  • the current detection element 211 may include one or more elements, which is not limited herein.
  • the first switching unit 212 includes a first terminal 1 and a second terminal 2
  • the second switching unit includes a first terminal 1 and a second terminal 2, wherein the first terminal of the first switching unit 212 1 is electrically connected to one of the two output terminals, the second terminal 2 of the first switch unit is electrically connected to the first terminal 1 of the second switch unit, and the second terminal 2 of the second switch unit is connected to the current detection element 211
  • the first terminal 1 of is connected electrically, and the second terminal 2 of the current detection element 211 is used to be electrically connected to one terminal of the cell 230.
  • the first terminal 1 of the first switching unit 212 is electrically connected to the output terminal P ⁇ , and the second terminal 2 of the current detection element 211 is used to electrically connect with the negative electrode of the battery cell 230.
  • the first terminal 1 of the first switching unit 212 is electrically connected to the output terminal P-
  • the second terminal of the current detection element 211 is used to electrically connect with the positive electrode of the cell 230
  • the first One terminal is electrically connected to the output terminal P+.
  • connection relationship between the current detection element 211, the first switch unit 212, and the second switch unit 213 is only a schematic illustration, as long as the three components form a series relationship on the loop, this embodiment of the present application does not make Any limitation.
  • the first switch unit 212 may also be disposed between the current detection element 211 and the second switch unit 213, one terminal of the current detection element 211 is electrically connected to the output terminal P-, and one terminal of the second switch unit 213 is used to The negative electrode of the cell 230 is electrically connected.
  • the control terminal 3 of the first detection unit 221 includes a discharge control terminal (DO terminal) and a charge control terminal (CO terminal)
  • the first switch unit 212 includes a first discharge switching element 212-1 and a first charge switching element 212-2
  • the first discharge switching element 212-1 includes a first terminal (G1 terminal), the first terminal (G1 terminal) of the first discharge switching element 212-1 and the discharge control terminal (DO terminal) of the first detection unit 221 ) Electrically connected
  • the first charge switching element 212-2 includes a first terminal (G2 terminal), the first terminal (G2 terminal) of the first charge switching element 212-2 and the charge control terminal (CO terminal) of the first detection unit 221 ) Electrical connection;
  • the control terminal 3 of the second detection unit 222 includes a discharge control terminal (DO terminal) and a charge control terminal (CO terminal), and the second switch unit 213 includes a second discharge switching element 213-1 and a second charge switching element 213-2,
  • the second discharge switching element 213-1 includes a first terminal (G1 terminal), the first terminal (G1 terminal) of the second discharge switching element 213-1 and the discharge control terminal (DO terminal) of the second detection unit 222 are electrically connected,
  • the second charging switching element 213-2 includes a first terminal (G2 terminal), the first terminal (G2 terminal) of the second charging switching element 212-2 and the charging control terminal (CO terminal) of the second detection unit 222 are electrically connected connection.
  • the discharge control terminal is used to control the charging circuit
  • the charging control terminal is used to control the charging circuit.
  • the discharge switching element and the charging switching element may be metal-oxide-semiconductor (MOS) tubes.
  • the first detection unit 221 detects that the voltage U 0 across Rs is greater than U 1 , the first detection unit 221 outputs a control signal to the G2 terminal through the CO terminal to turn off the first charging switch element 212- 2. To disconnect the charging circuit.
  • the second detection unit 222 detects that the voltage U 0 across Rs is greater than U 2 , the second detection unit 222 outputs a control signal to the G2 terminal through the CO terminal to turn off the second charging switch element 213-2, Disconnect the charging circuit.
  • the first detection unit 221 detects that the voltage U 0 across Rs is greater than U 1 , the first detection unit 221 outputs a control signal to the G1 terminal through the DO terminal to turn off the first discharge switching element 212-1 To open the discharge circuit.
  • the second detection unit 222 detects that the voltage U 0 across Rs is greater than U 2 , the second detection unit 222 outputs a control signal to the G1 terminal through the DO terminal to disconnect the discharge control MOS tube to disconnect the discharge circuit .
  • the first detection unit 221 further includes a VS (voltage sense) terminal, where the VS terminal represents a voltage detection terminal, and the VS terminal may be directly connected to the first switching unit 212 through a resistor R 12 or The first terminal 1 of the first terminal, thereby realizing the voltage detection of the first terminal 1 of the first switching unit 212.
  • the second detection unit 222 further includes a VS terminal, and the VS terminal may be directly connected to the first terminal 1 of the second switching unit 213 through a resistor R 22 , so as to realize the voltage to the first terminal 1 of the second switching unit 213 Detection.
  • a filter capacitor is connected in parallel between the two detection terminals of the current detection element in each detection unit.
  • the battery protection circuit 200 further includes:
  • the first filter capacitor 241 is connected in parallel between the two detection terminals for detecting the voltage across the current detection element 211 in the first detection unit 221.
  • the battery protection circuit 200 further includes:
  • the second filter capacitor 242 is connected in parallel between the two detection terminals for detecting the voltage across the current detection element 211 in the second detection unit 222.
  • the terminals for detecting the voltage across Rs in the first detection unit 221 are the VSS terminal and the IS terminal, the first filter capacitor 241 is the capacitor C 12 , and the two terminals of the capacitor C 12 are respectively connected to the first detection unit
  • the VSS terminal of 221 is connected to the IS terminal, and the voltage across the capacitor C 12 is the voltage between the VSS terminal and the IS terminal or the voltage across Rs.
  • the detection terminals for detecting the voltage across Rs in the second detection unit 222 are the VSS terminal and the IS terminal
  • the second filter capacitor 242 is the capacitor C 22
  • the two terminals of the capacitor C 22 are respectively connected to the second detection unit 222
  • the VSS terminal is connected to the IS terminal
  • the voltage across the capacitor C 22 is the voltage between the VSS terminal and the IS terminal or the voltage across Rs.
  • a first detection unit 221 for detecting a terminal voltage detected across the terminals IS1 and IS2 Rs of the terminal, a first filter capacitor 241 to capacitor C 12, the capacitance C of the two first detection terminal 12, respectively,
  • the IS1 terminal and the IS2 terminal of the unit 221 are connected, and the voltage across the capacitor C 12 is the voltage between the IS1 terminal and the IS2 terminal or the voltage across Rs.
  • the terminals for detecting the voltage across Rs in the second detection unit 222 are the IS1 terminal and the IS2 terminal
  • the second filter capacitor 242 is the capacitor C 22
  • the two terminals of the capacitor C 22 are respectively connected to the terminals of the second detection unit 222
  • the IS1 terminal is connected to the IS2 terminal
  • the voltage across the capacitor C 22 is the voltage between the IS1 terminal and the IS2 terminal or the voltage across Rs.
  • first detection unit and the second detection unit share one current detection element can reduce the impedance in the circuit, but if the two detection terminals of the first detection unit or the second detection unit are short-circuited or the two terminals of the filter capacitor occur A short circuit may prevent the overcurrent protection of the battery protection circuit. Taking FIG.
  • the embodiment of the present application may also provide a fault isolation unit in the battery protection circuit, so that In the case where the two detection terminals of the one detection unit or the second detection unit are short-circuited or the two terminals of the filter capacitor are short-circuited, current may also flow through the current detection element to achieve double protection for the battery.
  • the battery protection circuit 200 further includes:
  • the first fault isolation unit 250 is electrically connected to the first detection unit 221 and the current detection element 221, respectively, so that when a circuit electrically connected to the first terminal 1 of the first fault isolation unit 250 is short-circuited, the current detection element There is no short circuit at both ends of 221, wherein the first terminal 1 of the first fault isolation unit 250 is electrically connected to one detection terminal of the first detection unit 221.
  • FIG. 5 show the case where the first fault isolation unit 250 is electrically connected to one detection terminal of the first detection unit 221 and one terminal of the current detection element 211, the difference is that
  • the first fault isolation unit 250 shown in (a) of FIG. 5 is electrically connected to the detection terminal 1 of the first detection unit 221 and the terminal 1 of the current detection element 211, respectively, and to the first terminal 1 of the first fault isolation unit 250
  • the detection terminal of the electrically connected first detection unit 221 is the detection terminal 1, the first fault isolation unit 250 shown in (b) of FIG.
  • the detection terminal of the first detection unit 221 electrically connected to the first terminal 1 of the first fault isolation unit 250 is the detection terminal 2.
  • (C) in FIG. 5 shows a case where the first fault isolation unit 250 is electrically connected to the two detection terminals of the first detection unit 221 and the two terminals of the current detection element 211, respectively, where the first fault isolation unit 250 Including two fault isolation elements, the first terminal 1 of the first fault isolation unit 250 may be the first terminal 1 of any fault isolation element.
  • the circuit electrically connected to the first terminal of the first fault isolation unit 250 may be various possible circuits, for example, the circuit may be used in the first detection unit 221 to detect the voltage of the current detection element 211 The circuit between the two detection terminals (for example, the VSS terminal and the IS terminal shown in FIG. 3).
  • the circuit may also be a first filter capacitor, which is not limited in this embodiment of the present application.
  • the first fault isolation unit 250 may be a unit module composed of one or more elements.
  • the embodiment of the present application provides two possible ways (ie, way 1 and way 2), so that no short circuit occurs at both ends of the current detection element 211.
  • the first fault isolation unit 250 includes one fault isolation element, corresponding to (a) and (b) in FIG. 5, and in Mode 2, the first fault isolation unit 250 includes two fault isolation elements, corresponding to (C) in 5. It should be understood that these two modes are only for illustrative purposes, and should not be limited to the embodiments of the present application.
  • the first fault isolation unit 250 is electrically connected to one detection terminal of the first detection unit 221 and one terminal of the current detection element 211, respectively, such that between or between the two detection terminals of the first detection unit 221 When a filter capacitor is short-circuited, the second detection unit 222 can work normally.
  • the first fault isolation unit 250 includes a first fault isolation element 251
  • the first fault isolation element 251 includes a first terminal 1 and a second terminal 2
  • the first fault The first terminal 1 of the isolation element 251 is the first terminal of the first fault isolation unit 250
  • the two detection terminals of the first detection unit 221 include the first detection terminal (for example, the IS terminal in FIG. 6, or, 7 IS1 terminal) and a second detection terminal (for example, the VSS terminal in FIG. 6 or the IS2 terminal in FIG.
  • the two terminals of the current detection element 211 include a first terminal 1 and a second terminal 2,
  • the first terminal 1 of the first fault isolation element 251 is electrically connected to the first detection terminal 1 of the first detection unit 221
  • the second terminal 2 of the first fault isolation element 251 is electrically connected to the first terminal 1 of the current detection element 211
  • the second terminal 2 of the current detection element 211 is electrically connected to the second detection terminal of the first detection unit 221.
  • the first fault isolation element 251 may be a resistor R 13 .
  • first fault isolation element 251 may include one or more elements, which is not limited herein.
  • the working principle process of the battery protection circuit including the first fault isolation element 251 will be described in detail below.
  • the working principle of the battery protection circuit during the discharging process is similar to the working principle of the battery protection circuit during the charging process.
  • the current flow in the charging circuit will have two paths.
  • the first branch terminal P+ ⁇ cell 230 ⁇ R 13 ⁇ second Switching unit 213 ⁇ first switching unit 212 ⁇ terminal P-, where the current part passing through the cell 230 flows to R 13 through the VSS terminal and the IS terminal
  • the second branch terminal P+ ⁇ cell 230 ⁇ Rs ⁇ second switch Unit 213 ⁇ first switch unit 212 ⁇ terminal P-, that is, in this case, R 13 and Rs form a parallel relationship.
  • the second detection unit 222 can detect the voltage across Rs (also the voltage across R 13 in parallel with Rs). Since the total current of the parallel circuit formed by R 13 and Rs is the current through the cell 230, the voltage across Rs detected by the second detection unit 222 and the equivalent impedance of the circuit formed by the parallel connection of R 13 and Rs are known In this way, the current through the cell 230 can be obtained. Therefore, the conduction or disconnection of the charging loop can be controlled by detecting the voltage across Rs, so as not to affect the second detection unit 222 and the second switching unit 213. Stream protection, in addition, will not burn out the first detection unit 221.
  • a charging current to have two-way circuit a first branch: cell terminal P + ⁇ 230 ⁇ R 13 ⁇ second switching unit 213 ⁇ first switching unit 212 ⁇ terminal P-, where part of the current through cell 230 flows through C 12 to R 13 , second branch: terminal P+ ⁇ cell 230 ⁇ Rs ⁇ second switching unit 213 ⁇ first Switching unit 212 ⁇ terminal P-, the same reason, in this case, R 13 and Rs form a parallel relationship.
  • the first fault isolation unit 250 includes two fault isolation elements, each of which is electrically connected to one detection terminal of the first detection unit 221 and one terminal of the current detection element 211, so that, for example, the first When a short circuit occurs between the two detection terminals of the filter capacitor or the first detection unit 221, the second detection unit 222 can work normally.
  • FIG. 9 and 10 are schematic circuit diagrams of the battery protection circuit. It should be noted that the positions of the two detection units in FIG. 10 are interchanged, which is another possible connection relationship between the two detection units and other components.
  • the first fault isolation unit 250 includes; a first fault isolation element 251 and a second fault isolation element 252, the first fault isolation element 251 includes the first terminal 1 and The second terminal 2, the second fault isolation element 252 includes a first terminal 1 and a second terminal 2, the first terminal 1 of the first fault isolation element 251 or the first terminal 1 of the second fault isolation element 252 is the first fault isolation
  • the first terminal 1 of the unit 250, and the two detection terminals of the first detection unit 221 include a first detection terminal (for example, the IS1 terminal in FIG. 9 or FIG. 10) and a second detection terminal (for example, FIG. 9 or FIG. 10 IS2 terminal), the two terminals of the current detection element 211 includes a first terminal 1 and a second terminal 2, wherein,
  • the first terminal 1 of the first fault isolation element 251 is electrically connected to the first detection terminal 1 of the first detection unit 221, and the second terminal 2 of the first fault isolation element 251 is electrically connected to the first terminal 1 of the current detection element 211
  • the first terminal 1 of the second fault isolation element 252 is electrically connected to the second detection terminal 2 of the first detection unit 221
  • the second terminal 2 of the second fault isolation element 251 is electrically connected to the second terminal 2 of the current detection element.
  • the first detection terminal 1 and the second detection terminal 2 of a detection unit 221 are both current detection terminals.
  • the first fault isolation element 251 may be a resistor R 13 and the second fault isolation element may be a resistor R 14 .
  • first fault isolation element 251 and the second fault isolation element 251 may include one or more elements, which is not limited herein.
  • the operating principle is the same as that of mode 1.
  • the current flow in the charging circuit will have two paths, the first branch: terminal P+ ⁇ cell 230 ⁇ R 14 ⁇ R 13 ⁇ second switching unit 213 ⁇ first switching unit 212 ⁇ terminal P-, the second Branch: terminal P+ ⁇ cell 230 ⁇ Rs ⁇ second switch unit 213 ⁇ first switch unit 212 ⁇ terminal P-, in this case, R 14 and R 13 form a parallel relationship with Rs, and the The current may pass through Rs, and the second detection unit 222 may detect the voltage across Rs.
  • the conduction or disconnection of the charging loop can be controlled by detecting the voltage across Rs, so that it does not affect the second detection unit 222 and the first The over-current protection of the two switch units 213 will not burn out the first detection unit 221 or the first filter capacitor 241.
  • the battery protection circuit provided by the embodiment of the present application, by providing a first fault isolation unit electrically connected to the first detection unit and the current detection element, in some cases, for example, the first detection unit is used to detect current When a short circuit occurs between two detection terminals of the voltage across the detection element, or two of the first filter capacitors connected in parallel between the two detection terminals of the first detection unit for detecting the voltage of the current detection element
  • the first fault isolation unit due to the provision of the first fault isolation unit, the current can still flow through the current detection element, a voltage is formed across the current detection element, and the circuit can be controlled by detecting the voltage across the current detection element
  • the on or off of will not affect the overcurrent protection of the second detection unit and the second switching unit, and in addition, will not burn out the first detection unit or the first filter capacitor.
  • the resistance value of the first fault isolation unit 250 and the current detection element 211 can be designed reasonably to try to make the equivalent impedance of the circuit formed by the first fault isolation unit 250 and the current detection element 211 in parallel
  • the absolute value of the difference with the resistance value of the current detection element 211 is less than or equal to the preset value.
  • the preset value may be 50% of the resistance value of the current detection unit. Theoretically, the smaller the preset value, the better, the closer the effects of the overcurrent protection before the fault and the overcurrent protection after the fault, the higher the reliability of the overcurrent protection.
  • the resistance value of the current detection element 211 is a resistance of milliohm level
  • the resistance value of the first fault isolation unit 250 is a resistance of ohm level.
  • common values of the current detection element 211 are 5 m ⁇ , 3 m ⁇ , 2 m ⁇ , and 1.5 m ⁇ .
  • the resistance value of the first fault isolation unit 250 and the current detection element 211 Explain the relationship.
  • R S 5 m ⁇
  • R 13 3.3 ⁇
  • U′ 2 is the preset threshold of the overcurrent detection voltage of the second detection unit 222
  • the resistance value after parallel connection is 4.99m ⁇
  • the first fault isolation unit 250 includes multiple elements, the relationship between the resistance value of the elements connected in series and the equivalent impedance of the circuit formed in parallel between the current detection units is similar to the above, and will not be repeated here. .
  • the absolute value of the difference between the equivalent impedance of the circuit formed by the first fault isolation circuit and the current detection element in parallel and the resistance value of the current detection element is less than or equal to the preset value Value, before and after certain faults occur, for example, before and after a short circuit occurs between the two detection terminals used to detect the voltage across the current detection element in the first detection unit, or in parallel between the two in the first detection unit Before and after a short circuit occurs between the two terminals of the first filter capacitor between the detection terminals, the difference of the current threshold through the cell can be made smaller, and thus, the reliability of the overcurrent protection can be improved.
  • the first fault isolation unit is provided between the first detection unit and the current detection element.
  • the second fault isolation unit may also be provided between the second detection unit and the current detection element to achieve Double protection of the battery.
  • the battery protection circuit 200 further includes:
  • the second fault isolation unit 260 is electrically connected to the second detection unit 222 and the current detection element 221, respectively, so that when a circuit electrically connected to the first terminal 1 of the second fault isolation unit 260 is short-circuited, the current detection element There is no short circuit at both ends of 221, wherein the first terminal 1 of the second fault isolation unit 260 is electrically connected to one detection terminal of the second detection unit 222.
  • FIG. 5 show the case where the second fault isolation unit 260 is electrically connected to one detection terminal of the second detection unit 222 and one terminal of the current detection element 211, the difference is that
  • the second fault isolation unit 260 shown in (a) of FIG. 5 is electrically connected to the detection terminal 1 of the second detection unit 222 and the terminal 1 of the current detection element 211, respectively, and to the first terminal 1 of the second fault isolation unit 260
  • the detection terminal of the second detection unit 221 electrically connected is the detection terminal 1, the detection terminal 2 of the second fault isolation unit 260 and the second detection unit 222 and the terminal 2 of the current detection element 211 shown in (b) of FIG.
  • the detection terminal of the second detection unit 222 electrically connected to the first terminal 1 of the second fault isolation unit 260 is the detection terminal 2.
  • (C) in FIG. 5 shows a case where the second fault isolation unit 260 is electrically connected to the two detection terminals of the second detection unit 222 and the two terminals of the current detection element 211, wherein the second fault isolation unit 260 includes Two fault isolation elements, the first terminal 1 of the second fault isolation unit 260 may be the first terminal 1 of any fault isolation element.
  • the circuit electrically connected to the first terminal of the second fault isolation unit 260 may be various possible circuits, for example, the circuit may be used to detect the voltage of the current detection element 211 in the second detection unit 222 The circuit between the two detection terminals (for example, the IS1 terminal and the IS2 terminal shown in FIG. 3).
  • the circuit may also be a second filter capacitor, which is not limited in this embodiment of the present application.
  • the second fault isolation unit 260 may be a unit module composed of one or more elements.
  • the embodiment of the present application also provides two possible implementation manners (ie, Mode 3 and Mode 4), so that the current detection element There is no short circuit at both ends of 211.
  • Mode 3 the second fault isolation unit 260 includes one fault isolation element, corresponding to (a) and (b) in FIG. 5, and in Mode 4, the second fault isolation unit 260 includes two fault isolation elements, corresponding to (C) in 5. It should be understood that these two modes are only for illustrative purposes, and should not be limited to the embodiments of the present application.
  • the second fault isolation unit 260 is electrically connected to one detection terminal of the second detection unit 222 and one terminal of the current detection element 211, respectively, such that between or between the two detection terminals of the second detection unit 222 When the filter capacitor 242 is short-circuited, the first detection unit 221 can work normally.
  • the second fault isolation unit 260 includes a third fault isolation element 261, and the third fault isolation element 261 includes a first terminal 1 and a second terminal 2, the third The first terminal 1 of the fault isolation element 261 is the first terminal 1 of the second fault isolation unit 260, and the two detection terminals of the second detection unit 222 include a first detection terminal (for example, the IS terminal in FIG. 6, or , The IS1 terminal in FIG. 7) and the second detection terminal (for example, the VSS terminal in FIG. 6, or the IS2 terminal in FIG.
  • the two terminals of the current detection element 221 include the first terminal 1 and the second terminal 2, wherein the first terminal 1 of the third fault isolation element 261 is electrically connected to the first terminal 1 of the second detection unit 222, and the second terminal 2 of the third fault isolation element 261 and the first terminal 1 of the current detection element 211 The second terminal 2 of the current detection element 211 and the second terminal of the second detection unit 222 are electrically connected.
  • the third fault isolation element 261 may be a resistor R 23 .
  • the third fault isolation element 261 may include one or more elements, which is not limited herein.
  • the working principle process of the battery protection circuit including the third fault isolation element 261 will be described in detail below.
  • the working principle of the battery protection circuit during the discharging process is similar to the working principle of the battery protection circuit during the charging process.
  • the current flowing in the charging circuit will have two paths.
  • the first branch terminal P+ ⁇ cell 230 ⁇ R 23 ⁇ second Switching unit 213 ⁇ first switching unit 212 ⁇ P-, where the current part passing through the cell 230 flows to R 23 through the VSS terminal and the IS terminal
  • the second branch terminal P+ ⁇ cell 230 ⁇ Rs ⁇ second switching unit 213 ⁇ first switch unit 212 ⁇ terminal P-, that is, in this case, R 23 and Rs form a parallel relationship.
  • the first detection unit 221 can detect the voltage across Rs (also the voltage across R 23 in parallel with Rs). Since the total current of the parallel circuit formed by R 23 and Rs is the current through the cell 230, the voltage across Rs detected by the first detection unit 221 and the equivalent impedance of the circuit formed by the parallel connection of R 23 and Rs are known In this way, the current through the cell 230 can be obtained. Therefore, the conduction or disconnection of the charging loop can be controlled by detecting the voltage across Rs, so that it does not affect the overcurrent of the first detection unit 221 and the first switching unit 212 In addition, the stream protection will not burn out the second detection unit 222.
  • the current flow in the charging circuit will have two paths.
  • the first branch terminal P+ ⁇ cell 230 ⁇ R 23 ⁇ second switching unit 213 ⁇ first switching unit 212 ⁇ P-, where the current part passing through the cell 230 flows to R 23 through C 22
  • the second branch terminal P+ ⁇ cell 230 ⁇ Rs ⁇ second switching unit 213 ⁇ first switch Unit 212 ⁇ terminal P-, the same reason, in this case, R 23 and Rs form a parallel relationship.
  • the second fault isolation unit 260 includes two fault isolation elements, each of which is electrically connected to one detection terminal of the second detection unit 222 and one terminal of the current detection element 211, so that, for example, the second When a short circuit occurs between the two detection terminals of the filter capacitor 242 or the second detection unit 222, the first detection unit 221 can work normally.
  • the second fault isolation unit 260 includes; a third fault isolation element 261 and a fourth fault isolation element 262, wherein the third fault isolation element 261 includes the first Terminal 1 and second terminal 2, fourth fault isolation element 262 include first terminal 1 and second terminal 2, first terminal 1 of third fault isolation element 261 or first terminal 1 of said fourth fault isolation element 262 Is the first terminal 1 of the second fault isolation unit 260, and the two detection terminals of the second detection unit 222 include a first detection terminal (for example, the IS1 terminal in FIG. 9 or FIG. 10) and a second detection terminal (for example , IS2 terminal in FIG. 9 or FIG. 10), the two terminals of the current detection element 211 include a first terminal 1 and a second terminal 2, wherein,
  • the first terminal 1 of the third fault isolation element 261 is electrically connected to the first detection terminal 1 of the second detection unit 222, and the second terminal 2 of the third fault isolation element 261 is electrically connected to the first terminal 1 of the current detection element 211,
  • the first terminal 1 of the fourth fault isolation element 262 is electrically connected to the second detection terminal 2 of the second detection unit 222, the second terminal 2 of the fourth fault isolation element 251 is connected to the second terminal 2 of the current detection element 211, Both the first detection terminal 1 and the second detection terminal 2 of the second detection unit 222 are current detection terminals.
  • the third fault isolation element 261 may be a resistor R 23 and the fourth fault isolation element may be a resistor R 24 .
  • third fault isolation element and the fourth fault isolation element may include one or more elements, which is not limited herein.
  • the operating principle is the same as that of Mode 3.
  • the current flow in the charging circuit will have two paths, the first branch: terminal P+ ⁇ cell 230 ⁇ R 24 ⁇ R 23 ⁇ second switching unit 213 ⁇ first switching unit 212 ⁇ terminal P-, the second Branch: terminal P+ ⁇ cell 230 ⁇ Rs ⁇ second switch unit 213 ⁇ first switch unit 212 ⁇ terminal P-, in this case, R 24 and R 23 form a parallel relationship with Rs, and the The current may pass through Rs, and the first detection unit 221 may detect the voltage across Rs.
  • the battery protection circuit provided by the embodiment of the present application, by providing a second fault isolation unit electrically connected to the second detection unit and the current detection element, in some cases, for example, the second detection unit is used to detect current When a short circuit occurs between the two detection terminals of the voltage across the detection element, or when a short circuit occurs between the two terminals of the second filter capacitor connected in parallel between the two detection terminals, the second The fault isolation unit can make the current pass through the second fault isolation unit and the current detection element respectively, and the second fault isolation unit and the current detection element form a parallel relationship, so that there is a voltage across the current detection element, by detecting the voltage across the current detection element The conduction or disconnection of the control loop will not affect the overcurrent protection of the first detection unit and the first switching unit, and will not burn out the second detection unit or the second filter capacitor.
  • the resistance value of the second fault isolation unit 260 and the current detection element 221 can also be designed to make the second fault isolation unit 260 and the current
  • the absolute value of the difference between the equivalent impedance of the circuit formed in parallel by the detection elements 221 and the resistance value of the current detection element 221 is less than or equal to the preset value.
  • the preset value may be 50% of the resistance value of the current detection unit. Theoretically, the smaller the preset value, the better, the closer the effects of the overcurrent protection before the fault and the overcurrent protection after the fault, the higher the reliability of the overcurrent protection.
  • the resistance value of the current detection element 211 is a resistance of milliohm level
  • the resistance value of the second fault isolation unit 260 is a resistance of ohm level.
  • An embodiment of the present application further provides a battery protection board, which includes the battery protection circuit in any possible implementation manner in the above embodiments.
  • the battery protection board may be the battery shown in FIG. 1 Protection board 113-1.
  • An embodiment of the present application further provides a battery including a battery cell and a battery protection board.
  • the battery protection board includes a battery protection circuit in any possible implementation manner of the foregoing embodiment.
  • the battery may be a battery 1show battery 113.
  • the disclosed system, device, and method may be implemented in other ways.
  • the device embodiments described above are only schematic.
  • the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented.
  • the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical, or other forms.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.
  • the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.
  • the technical solution of the present application essentially or part of the contribution to the existing technology or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to enable a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application.
  • the foregoing storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes .

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Protection Of Static Devices (AREA)
  • Secondary Cells (AREA)

Abstract

La présente invention concerne un circuit de protection de batterie, une plaque de protection de batterie, une batterie et un dispositif terminal. Le circuit de protection de batterie comprend une première unité de détection, une seconde unité de détection et un élément de détection de courant connectés en série à une cellule, une première unité de commutation et une seconde unité de commutation, de manière à former une boucle de charge ou une boucle de décharge, la première unité de détection correspondant à la première unité de commutation, la seconde unité de détection correspondant à la seconde unité de commutation, et chaque unité de détection commandant la conduction ou la déconnexion de l'unité de commutation correspondante en fonction de la tension détectée aux bornes de deux extrémités du même élément de détection de courant, de manière à commander la conduction ou la déconnexion de la boucle. Par l'activation d'une première unité de détection et d'une seconde unité de détection pour détecter la tension aux bornes de deux extrémités du même élément de détection de courant de façon à réaliser la détection du courant traversant une cellule, le nombre d'éléments de détection de courant dans un circuit de protection de batterie peut être efficacement réduit, de façon à limiter l'impédance d'un circuit de protection de batterie, réduisant ainsi la perte d'une plaque de protection de batterie.
PCT/CN2019/121914 2018-12-21 2019-11-29 Circuit de protection de batterie, plaque de protection de batterie, batterie et dispositif terminal WO2020125375A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP19898904.8A EP3902078B1 (fr) 2018-12-21 2019-11-29 Circuit de protection de batterie, plaque de protection de batterie, batterie et dispositif terminal
KR1020217023126A KR102666759B1 (ko) 2018-12-21 2019-11-29 배터리 보호 회로, 배터리 보호 보드, 배터리 및 단말 장치
US17/416,519 US11962143B2 (en) 2018-12-21 2019-11-29 Battery protection circuit, battery protection board, battery, and terminal device

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201811572828.9 2018-12-21
CN201811572828 2018-12-21
CN201910336826.8A CN111355222B (zh) 2018-12-21 2019-04-25 电池保护电路、电池保护板、电池和终端设备
CN201910336826.8 2019-04-25

Publications (1)

Publication Number Publication Date
WO2020125375A1 true WO2020125375A1 (fr) 2020-06-25

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220085598A1 (en) * 2018-12-21 2022-03-17 Honor Device Co., Ltd. Battery protection circuit, battery protection board, battery, and terminal device

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JP2010115070A (ja) * 2008-11-10 2010-05-20 Panasonic Corp 二次電池の過充電保護回路
CN104218542A (zh) * 2014-09-12 2014-12-17 东莞新能德科技有限公司 电池保护电路
CN207318660U (zh) * 2017-10-20 2018-05-04 欣旺达电子股份有限公司 Pcm保护测试电路
CN207481668U (zh) * 2017-11-13 2018-06-12 深圳市睿德电子实业有限公司 平衡车电池的双重保护电路

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010115070A (ja) * 2008-11-10 2010-05-20 Panasonic Corp 二次電池の過充電保護回路
CN104218542A (zh) * 2014-09-12 2014-12-17 东莞新能德科技有限公司 电池保护电路
CN207318660U (zh) * 2017-10-20 2018-05-04 欣旺达电子股份有限公司 Pcm保护测试电路
CN207481668U (zh) * 2017-11-13 2018-06-12 深圳市睿德电子实业有限公司 平衡车电池的双重保护电路

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220085598A1 (en) * 2018-12-21 2022-03-17 Honor Device Co., Ltd. Battery protection circuit, battery protection board, battery, and terminal device
US11962143B2 (en) * 2018-12-21 2024-04-16 Honor Device Co., Ltd. Battery protection circuit, battery protection board, battery, and terminal device

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