CN113809788A - Protective circuit - Google Patents

Protective circuit Download PDF

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Publication number
CN113809788A
CN113809788A CN202110673991.XA CN202110673991A CN113809788A CN 113809788 A CN113809788 A CN 113809788A CN 202110673991 A CN202110673991 A CN 202110673991A CN 113809788 A CN113809788 A CN 113809788A
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CN
China
Prior art keywords
circuit
battery pack
switching element
switching
charging
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
CN202110673991.XA
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Chinese (zh)
Inventor
植田友成
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schott Nippon KK
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Schott Nippon KK
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Filing date
Publication date
Priority claimed from JP2021092895A external-priority patent/JP7421516B2/en
Application filed by Schott Nippon KK filed Critical Schott Nippon KK
Publication of CN113809788A publication Critical patent/CN113809788A/en
Pending legal-status Critical Current

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    • 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
    • H02J7/0068—Battery or charger load switching, e.g. concurrent charging and load supply
    • 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
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00304—Overcurrent protection
    • 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
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00308—Overvoltage protection
    • 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
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0031—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using battery or load disconnect circuits

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Burglar Alarm Systems (AREA)
  • Oscillators With Electromechanical Resonators (AREA)

Abstract

The invention provides a protection circuit and a battery pack for protecting a battery pack from overcharge and overheating with a simpler configuration. The present invention provides a protection circuit for protecting a battery pack of a secondary battery such as a lithium ion battery from overcharge and overheat, the protection circuit including: a battery pack in which 1 or more secondary battery cells are connected; a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a first switching element and a second switching element which are connected in parallel to a current circuit between the battery pack and an external terminal, and which receive a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section.

Description

Protective circuit
Technical Field
The invention relates to a protection device of a battery pack (battery pack) with a protection element, a protection circuit and the battery pack.
Background
Even in the form of a single battery used in a mobile phone, the lithium ion battery is produced in the form of a battery pack, which is a battery pack in which the lithium ion battery is incorporated in a case in such a manner that a protection circuit (Safety Unit) for ensuring Safety is provided. The reason is that it is difficult to ensure practical safety of the cells of the lithium ion battery. The safety of lithium ion batteries is characterized by poor resistance to overcharge and overheating, for example. Therefore, the battery pack is configured by housing a protection circuit, a protection element, a fuse, and the like for securing safety in an external can such as a plastic case in cooperation with a battery, and controls charging and discharging of the battery by a charging and discharging control system (BMS) while detecting voltage, current, temperature, and the like.
In a battery pack having a plurality of secondary battery cells (cells) mounted therein, a protection element is connected in series with the battery to prevent the battery from being charged and discharged in an abnormal state. The protection element cuts off current when the battery is charged and discharged in an abnormal state. In order to cut off the current of the battery in case of abnormality, the protection element incorporates a fuse assembly formed of a low melting point metal which is fused by joule heat of overcurrent. Further, the protection element incorporates a thermistor, and when there is an abnormality that the battery is overcharged, the thermistor is energized to melt the fuse assembly of the low melting point metal by heating in a short time. (see patent document 1)
The Protection element is connected to a Protection Circuit of the battery pack, and the operation of the fuse module is controlled by a control element such as a Protection Integrated Circuit (Protection IC) and a Field Effect Transistor (FET) that monitor the voltage of each cell. For example, a protection element used in a charge/discharge control circuit of a battery pack described in patent document 2 senses an overcurrent of the battery pack and a rise in ambient temperature or energizes a thermistor under a predetermined condition to forcibly actuate a fuse, thereby cutting off the circuit. That is, the protection element may generate heat by a signal current when the protection circuit detects an abnormality generated in the machine, and fuse elements (also referred to as fuse elements) including a fusible alloy are fused by the heat to cut off the circuit, or fuse elements are fused by an overcurrent to cut off the circuit, thereby achieving machine safety.
The conventional battery pack has a complicated structure. That is, the protection circuit requires a plurality of protection elements, and at least different protection elements are used in the discharge system and the charging system, respectively. In addition, the protection circuit needs to include a plurality of semiconductor elements such as FETs (switching elements) and diodes (rectifying elements) constituting the switch, and at least 2 of them are used in the discharge circuit system and 2 are used in the charge circuit system, and the operation of the protection element is controlled by 1. The 2 signals output from the switching control section to the first and second shutters must always be in opposite phases to each other. The reason for this is that if the signals are in phase, a loop is formed between 2 switches and 2 protection elements, thus risking a system failure. The existing protection circuit has the risk in signal control.
[ Prior art documents ]
[ patent document ]
[ patent document 1] Japanese patent laid-open No. 2017-228379
[ patent document 2] Japanese patent laid-open No. 2012-231649
Disclosure of Invention
(problems to be solved by the invention)
The invention is provided for the purpose of realizing a protection circuit for protecting a battery pack (battery) from overcharge and overheating and a battery pack with a simpler structure, thereby reducing the risk of the system.
(means for solving the problems)
According to the present invention, there is provided a protection circuit for protecting a battery pack of a secondary battery such as a lithium ion battery from overcharge and overheating, the protection circuit including:
a battery pack (battery) formed by connecting more than 1 secondary battery; a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a first switching element and a second switching element which are connected in parallel to a current circuit between the battery pack and an external terminal, and which receive a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section.
The switching element of the present invention includes a switching Transistor such as a Field Effect Transistor (FET), a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), or a protection circuit module including the switching element.
The protection circuit of the present invention is applied to a charging/discharging device for a battery pack. That is, the present invention provides a charging/discharging device for a battery pack of a secondary battery such as a lithium ion battery, including: a battery pack in which 1 or more secondary battery cells are connected; a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a first switching element and a second switching element which are connected in parallel to a current circuit between the battery pack and an external terminal, and which receive a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section; the signal control unit turns off the first switching element and turns on the second switching element during charging, turns on the first switching element and turns off the second switching element during discharging, and controls the charging circuit and the discharging circuit to be turned on/off, and the protection element has a fuse element that fuses when a value of a current flowing through the charging circuit of the second switching element exceeds a predetermined fuse current value, or fuses when a voltage of the cell or the battery pack exceeds a predetermined voltage value by heat generation due to energization of the thermistor.
The protection circuit or the charge and discharge device of the present invention is applied to a battery pack. That is, the present invention provides a battery pack for a secondary battery such as a lithium ion battery, including: a battery pack in which 1 or more secondary battery cells are connected; a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a first switching element and a second switching element which are connected in parallel to a current circuit between the battery pack and an external terminal, and which receive a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section; the signal control part turns off the first switch element and turns on the second switch element during charging, turns on the first switch element and turns off the second switch element during discharging, and controls the charging circuit and the discharging circuit to be turned on/off, the protection element is to cut off the charging circuit by fusing the fuse element when the value of the current flowing through the charging circuit of the second switch element exceeds a predetermined fusing current value, and the signal control part turns off the charging circuit by fusing the fuse element by heating the thermistor when the cell or the battery pack exceeds a predetermined voltage value.
The battery pack of the present invention is used for a cordless electric apparatus such as a mobile device. That is, the present invention provides an electric apparatus using a battery pack of a secondary battery such as a lithium ion battery, including: a battery pack in which 1 or more secondary battery cells are connected; a battery pack having a protection circuit or a charging/discharging device for controlling charging/discharging of the battery pack; and a machine body detachably connected to the battery pack, for charging the battery pack or receiving power supply from the battery pack to drive the machine body; the battery pack is provided with: a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a first switching element and a second switching element which are connected in parallel to a current circuit between the battery pack and an external terminal, and which receive a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section; the signal control part turns off the first switch element and turns on the second switch element during charging, turns on the first switch element and turns off the second switch element during discharging, and controls the charging circuit and the discharging circuit to be turned on/off, the protection element is to cut off the charging circuit by fusing the fuse element when the value of the current flowing through the charging circuit of the second switch element exceeds a predetermined fusing current value, and the signal control part turns off the charging circuit by fusing the fuse element by heating the thermistor when the cell or the battery pack exceeds a predetermined voltage value.
According to another aspect of the present invention, there is provided a protection circuit for protecting a battery pack of a secondary battery such as a lithium ion battery from overcharge and overheating, the protection circuit including: a battery pack formed by connecting more than 1 single body; a signal control unit for monitoring the voltage of the cell or the battery pack and outputting a control signal according to the measured value; a switching control element connected to a discharging circuit and a charging circuit between the battery pack and an external terminal of the battery pack, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a switching element connected to the signal control section.
Further, the protection circuit including the switching control element is applied to a charge/discharge device. That is, the present invention provides a charge/discharge device for a battery pack of a secondary battery such as a lithium ion battery including the switching control element, the charge/discharge device including: a battery pack formed by connecting more than 1 single body; a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a switching control element connected to a discharging circuit and a charging circuit between the battery pack and an external terminal of the battery pack, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a switching element connected to the signal control section; the switching control element can turn off the discharge circuit and turn on the charge circuit by the signal control section during charging, turn on the discharge circuit and turn off the charge circuit by the signal control section during discharging, and turn on/off control the charge circuit and the discharge circuit, and the protection element has a fuse element which is fused when the value of the current flowing through the charge circuit of the switching control element exceeds a predetermined fusing current value, or fused by the heat generation by the energization of the thermistor when the voltage of the cell or the battery pack exceeds a predetermined voltage value.
The protection circuit comprising the switching control element and the charging and discharging device can be used for a battery pack. That is, the present invention provides a battery pack for a secondary battery such as a lithium ion battery, including: a battery pack in which 1 or more secondary battery cells are connected; a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a switching control element connected to a discharging circuit and a charging circuit between the battery pack and an external terminal of the battery pack, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a switching element connected to the signal control section; the signal control part switches off the discharging circuit and switches on the charging circuit when charging, switches on the discharging circuit and switches off the charging circuit when discharging, and switches on/off the charging circuit and the discharging circuit, the protection element switches off the fuse component to switch off the charging circuit when the value of the current flowing through the charging circuit of the switching control element exceeds a predetermined fusing current value, and the signal control part switches off the charging circuit by heating the thermistor and fusing the fuse component when the single body or the battery pack exceeds a predetermined voltage value.
The battery pack including the switching control element of the present invention can be used for an electric apparatus such as a mobile device which does not use an electric wire. That is, the present invention provides an electric apparatus using a battery pack of a secondary battery such as a lithium ion battery, including: a battery pack in which 1 or more secondary battery cells are connected; a battery pack having a protection circuit or a charging/discharging device for controlling charging/discharging of the battery pack; and a machine body detachably connected to the battery pack, for charging the battery pack or receiving power supply from the battery pack to drive the machine body; the battery pack is provided with: a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a switching control element connected to a discharging circuit and a charging circuit between the battery pack and an external terminal of the battery pack, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a switching element connected to the signal control section; the signal control part switches off the discharging circuit and switches on the charging circuit when charging, switches on the discharging circuit and switches off the charging circuit when discharging, and switches on/off the charging circuit and the discharging circuit, the protection element switches off the fuse component to switch off the charging circuit when the value of the current flowing through the charging circuit of the switching control element exceeds a predetermined fusing current value, and the signal control part switches off the charging circuit by heating the thermistor and fusing the fuse component when the single body or the battery pack exceeds a predetermined voltage value.
(effect of the invention)
The invention provides a protection device for a battery pack, which is simpler in structure.
Drawings
Fig. 1 is a diagram showing a protection circuit 10 according to the present invention.
Fig. 2 is a diagram showing a protection circuit 20 according to the present invention.
Fig. 3 is a diagram showing a protection circuit 30 according to the present invention.
Fig. 4 is a diagram showing a protection circuit 40 of the present invention.
Fig. 5 is a diagram showing a protection circuit 50 according to embodiment 1 of the present invention.
Fig. 6 is a diagram showing a protection circuit 60 according to embodiment 2 of the present invention.
Fig. 7 is a diagram showing a protection circuit 70 according to embodiment 3 of the present invention.
Fig. 8 is a diagram showing a protection circuit 80 according to embodiment 4 of the present invention.
Fig. 9 is a diagram showing a buffering effect obtained by the delay circuit of the present invention.
Fig. 10 is a diagram showing a protection circuit 100 obtained by a modification of embodiment 4 of the present invention.
Detailed Description
As shown in fig. 1, a protection circuit 10 of the present invention is a protection circuit for protecting a battery pack of a secondary battery such as a lithium ion battery from overcharge and overheat, and includes: a battery pack 12 in which 1 or more secondary battery cells 11 are connected in series; a signal control unit 13 that outputs a control signal according to the voltage of the cell 11 or the battery pack 12; 1 first switching element 15-1 and 1 second switching element 15-2, which are connected in parallel to a current circuit between the battery pack 12 and the external terminal 14, and which receive a signal from the signal control section 13 to perform on/off control; and 1 protection element 16, which is provided with a fuse component 16-1 and a thermistor 16-2, wherein the fuse component 16-1 is connected in parallel with the discharge circuit, and the action of the thermistor 16-2 is controlled by a third switching element 15-3 connected to the signal control part 13. As shown in fig. 1, the protection circuit 10 can control the switching of the charge and discharge circuit only by the signal control section 13, so that the circuit configuration can be simplified and the risk of the control section generating a failure (error) can be reduced. The protection circuit 10 can delay the applied voltage by providing a delay circuit 89 including a resistance element 89-1 and a capacitor element 89-2 as shown in fig. 8 as necessary, and can buffer an overshoot current such as an inrush current at the time of switching.
The protection circuit 10 is applied to a charging and discharging device of a battery pack. That is, the present invention provides a charging/discharging device for a battery pack of a secondary battery such as a lithium ion battery, including: a battery pack 12 in which 1 or more secondary battery cells 11 are connected in series; a signal control unit 13 that outputs a control signal according to the voltage of the cell 11 or the battery pack 12; 1 first switching element 15-1 and 1 second switching element 15-2, which are connected in parallel to a current circuit between the battery pack 12 and the external terminal 14, and which receive a signal from the signal control section 13 to perform on/off control; and a protection element 16 having a fuse block 16-1 and a thermistor 16-2 built therein, the fuse block 16-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 16-2 being controlled by a third switching element 15-3 connected to the signal control section 13; the signal control unit 13 is capable of turning off the first switching element 15-1 and turning on the second switching element 15-2 during charging, turning on the first switching element 15-1 and turning off the second switching element 15-2 during discharging, and controlling the charging circuit and the discharging circuit to be turned on/off, and the protection element 16 has a fuse element 16-1, and the fuse element 16-1 is fused when the value of the current flowing through the charging circuit of the second switching element 15-2 exceeds a predetermined fusing current value, or is fused by the heat generated by the energization of the thermistor 16-2 when the voltage of the cell 11 or the battery pack 12 exceeds a predetermined voltage value.
In the protection circuit or the charge and discharge device, the second switching element 15-2 is disposed between the cell 11 or the battery pack 12 and the protection element 16. Alternatively, in another example of the protection circuit or the charge/discharge device of the present invention, the protection element 16 is disposed between the cell 11 or the battery pack 12 and the second switching element 15-2.
In the protection circuit or the charge/discharge device of the present invention, the first switching element 15-1 is connected between the battery pack 12 and the external terminal 14 of the battery pack, and includes 1 switching transistor for performing on/off control by receiving a signal from the signal control unit 13 that outputs a control signal according to the voltage of the cell 11, the second switching element 15-2 is connected in parallel with the first switching element 15-1, and includes 1 switching transistor for performing on/off control by receiving a signal from the signal control unit 13, and the first switching element 15-1 and the second switching element 15-2 are configured such that the bias directions of the internal diodes in the switching transistors are opposite to each other, and the signal control unit 13 performs on/off control such that the first switching element 15-1 is turned off and the second switching element 15-2 is turned on at the time of charging, the first switching element 15-1 is turned on and the second switching element 15-2 is turned off at the time of discharging. For example, if the first switching element 15-1 and the second switching element 15-2 are each composed of 1 field effect transistor, and the first switching element 15-1 and the second switching element 15-2 are configured such that the bias directions of the internal diodes in the field effect transistors are opposite to each other, the signal control unit 13 can perform on/off control such that the first switching element 15-1 is turned off and the second switching element 15-2 is turned on during charging, and the first switching element 15-1 is turned on and the second switching element 15-2 is turned off during discharging.
The protection circuit 10 may also be modified as the protection circuit 20 shown in fig. 2. Namely, the apparatus is provided with: a battery pack 22 in which 1 or more secondary battery cells 21 are connected in series; a signal control unit 23 that outputs a control signal according to the voltage of the cell 21 or the battery pack 22; 1 first switching element 25-1 and 1 second switching element 25-2, which are connected in parallel to a current circuit between the battery pack 22 and the external terminal 24, and which receive a signal from the signal control section 23 to perform on/off control; and a protection element 26 having a fuse block 26-1 and a thermistor 26-2 built therein, the fuse block 26-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 26-2 being controlled by a third switching element 25-3 connected to the signal control section 23; the signal control section 23 may branch the signal circuits thereof, provide an inverter element (inverting amplifier element) 27 in any one of the signal circuits, connect the gate of the first switching element 25-1 to one side of the branched signal circuit, and connect the gate of the second switching element 25-2 to the other side. In this case, one of the first and second switching elements 25-1 and 25-2 has the inverter element 27, and thus 1 signal path can be shared. In this modification, as shown in fig. 2, switching of the charge/discharge circuit is controlled by a single signal from the signal control unit 23, so that the circuit configuration can be simplified and the risk of an error occurring in the control unit can be reduced.
The protection circuit 10 of the present invention may be modified as the protection circuit 30 shown in fig. 3, and includes: a battery pack 32 in which 1 or more secondary battery cells 31 are connected in series; a signal control unit 33 that outputs a control signal according to the voltage of the cell 31 or the battery pack 32; 1 first switching element 35-1 and 1 second switching element 35-2, which are connected in parallel to a current circuit between the battery pack 32 and the external terminal 34, and which receive a signal from the signal control unit 33 to perform on/off control; and a protection element 36 having a fuse unit 36-1 and a thermistor 36-2 built therein, the fuse unit 36-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 36-2 being controlled by a third switching element 35-3 connected to the signal control section 33; the signal control unit 33 branches the signal circuits, and provides an inverter element (inverting amplifier element) 37 in any one of the signal circuits, and connects the gate of the first switching element 35-1 to one side of the branched signal circuit and the gate of the second switching element 35-2 to the other side. In this case, one of the first switching element 35-1 and the second switching element 35-2 has the inverter element 37, and thus 1 signal circuit can be shared. The protection element 36 is disposed between the battery pack 32 and the first switching element 35-1, and cuts off the charging circuit when the thermistor 36-2 and the fuse element 36-1 exceed a predetermined fusing temperature, or when the value of the current flowing through the fuse element 36-1 via the second switching element 35-2 exceeds a predetermined fusing current value, the thermistor 36-2 is energized to generate heat when the cell 31 or the battery pack 32 exceeds a predetermined voltage value by the signal control part 33 outputting a control signal according to the voltage of the cell 31 or the battery pack 32, and the fuse element 36-1 is connected in parallel to the first switching element 35-1. As shown in fig. 3, the protection circuit 30 can control the switching of the charge/discharge circuit by a single signal from the signal control unit 33, thereby simplifying the circuit configuration and reducing the risk of the control unit malfunctioning.
The signal control unit 13 of the protection circuit or the charge/discharge device of the present invention automatically turns on/off the switching transistor constituting the first switching element 15-1 and automatically turns off/on the switching transistor constituting the second switching element 15-2 by a control signal output according to the voltage of the cell 11 or the battery pack 12 when the cell 11 or the battery pack 12 exceeds a predetermined voltage value, and automatically turns on/off the switching transistor constituting the first switching element 15-1 and automatically turns on/off the switching transistor constituting the second switching element 15-2 by a control signal of the signal control unit 13 when the cell 11 or the battery pack 12 is less than the predetermined voltage value.
The first switching element 15-1 of the protection circuit or the charge/discharge device of the present invention includes 1 switching transistor connected to the discharge circuit such that the bias direction of the internal diode is forward with respect to the discharge direction, and the second switching element 15-2 includes 1 switching transistor connected to the charge circuit such that the bias direction of the internal diode is forward with respect to the charge direction.
The protection circuit or the charge/discharge device of the present invention can delay the applied voltage by providing the delay circuit 89 including the resistance element 89-1 and the capacitor element 89-2 as shown in fig. 8 as necessary, and can buffer an overshoot current such as an inrush current at the time of switching.
The protection circuit or the charge and discharge device of the present invention is applied to a battery pack. That is, the present invention provides a battery pack for a secondary battery such as a lithium ion battery, including: a battery pack 12 in which 1 or more secondary battery cells 11 are connected in series; a signal control unit 13 that outputs a control signal according to the voltage of the cell 11 or the battery pack 12; 1 first switching element 15-1 and 1 second switching element 15-2 connected in parallel to a current circuit between the battery pack 12 and the external terminal 14, and receiving a signal from the signal control section to perform on/off control; and a protection element 16 having a fuse block 16-1 and a thermistor 16-2 built therein, the fuse block 16-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 16-2 being controlled by a third switching element 15-3 connected to the signal control section 13; the signal control unit 13 controls the charging circuit and the discharging circuit to be turned on/off by turning off the first switching element 15-1 and turning on the second switching element 15-2 at the time of charging, and by turning on the first switching element 15-1 and turning off the second switching element 15-2 at the time of discharging, the protection element 16 is configured to cut off the charging circuit by fusing the fuse element 16-1 when the value of the current flowing through the charging circuit of the second switching element 15-2 exceeds a predetermined fusing current value, and the signal control unit 13 causes the thermistor 16-2 to generate heat and the fuse element 16-1 to fuse when the cell 11 or the battery pack 12 exceeds a predetermined voltage value, thereby cutting off the charging circuit.
The battery pack of the present invention is used for a cordless electric apparatus such as a mobile device. That is, the present invention provides an electric apparatus using a battery pack of a secondary battery such as a lithium ion battery, including: a battery pack 12 in which 1 or more secondary battery cells 11 are connected in series; a battery pack having a protection circuit or a charging/discharging device that controls charging/discharging of the battery pack 12; and a machine body detachably connected to the battery pack, for charging the battery pack or receiving power supply from the battery pack to drive the machine body; the battery pack is provided with: a signal control unit 13 that outputs a control signal according to the voltage of the cell 11 or the battery pack 12; 1 first switching element 15-1 and 1 second switching element 15-2, which are connected in parallel to a current circuit between the battery pack 12 and the external terminal 14, and which receive a signal from the signal control section 13 to perform on/off control; and a protection element 16 having a fuse block 16-1 and a thermistor 16-2 built therein, the fuse block 16-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 16-2 being controlled by a third switching element 15-3 connected to the signal control section 13; the signal control unit 13 turns off the first switching element 15-1 and turns on the second switching element 15-2 during charging, turns on the first switching element 15-1 and turns off the second switching element 15-2 during discharging, and controls the charging circuit and the discharging circuit to be turned on/off, and the protection element 16 is configured such that the fuse element 16-1 is fused to cut off the charging circuit when the value of the current flowing through the charging circuit of the second switching element 15-2 exceeds a predetermined fusing current value, and the thermistor 16-2 is heated to fuse the fuse element 16-1 by the signal control unit 13 when the cell 11 or the battery pack 12 exceeds a predetermined voltage value, thereby cutting off the charging circuit.
As shown in fig. 4, a protection circuit 40 according to the present invention is a protection circuit for protecting a battery pack of a secondary battery such as a lithium ion battery from overcharge and overheat, and includes: a battery pack 42 in which 1 or more cells 41 are connected in series; a signal control unit 43 that monitors the voltage of the cell 41 or the battery pack 42 and outputs a control signal according to the measurement amount; a switching control element 45 connected to a discharging circuit and a charging circuit between the battery pack 42 and the external terminal 44 of the battery pack, and receiving a signal from the signal control unit 43 to perform on/off control; and 1 protection element 46 having a fuse block 46-1 and a thermistor 46-2 built therein, the fuse block 46-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 46-2 being controlled by a switching element 48 connected to the signal control section 43. As shown in fig. 4, the protection circuit 40 can control the switching of the charge/discharge circuit by a single signal from the signal control unit 43, thereby simplifying the circuit configuration and eliminating the risk of an error due to switching the control unit. The protection circuit 40 can delay the applied voltage by providing a delay circuit 89 including a resistance element 89-1 and a capacitor element 89-2 as shown in fig. 8 as necessary, and can buffer an overshoot current such as an inrush current at the time of switching.
Further, the protection circuit including the switching control element is applied to a charge/discharge device. That is, the charge/discharge device provided with the switching control element according to the present invention includes: a battery pack 42 in which 1 or more cells 41 are connected in series; a signal control unit 43 that outputs a control signal according to the voltage of the cell 41 or the battery pack 42; a switching control element 45 connected to a discharging circuit and a charging circuit between the battery pack 42 and the external terminal 44 of the battery pack, and receiving a signal from the signal control unit 43 to perform on/off control; and a protection element 46 having a fuse block 46-1 and a thermistor 46-2 built therein, the fuse block 46-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 46-2 being controlled by a switching element 48 connected to the signal control section 43; the switching control element 45 is capable of turning off the discharging circuit and turning on the charging circuit by the signal control section 43 at the time of charging, turning on the discharging circuit and turning off the charging circuit by the signal control section 43 at the time of discharging, and on/off controlling the charging circuit and the discharging circuit, and the protection element 46 has a fuse element 46-1 which is fused when the value of the current flowing through the charging circuit of the switching control element 45 exceeds a predetermined fusing current value, or fused by the heat generation by the energization of the thermistor 46-2 when the voltage of the cell 41 or the battery pack 42 exceeds a predetermined voltage value.
The switching control element 45 of the present invention includes a selector, a switching controller, a Complementary Metal Oxide Semiconductor (CMOS) transistor, a switching transistor such as a MOSFET, an IGBT, or an FET, or a protection circuit module including the switching element. The switching element 48 includes a switching element such as a MOSFET, an IGBT, or an FET, or a protection circuit module including the switching element.
In the protection circuit or the charge and discharge device including the switching control element 45 of the present invention, the protection element 46 is disposed on the charge circuit between the cell 41 or the battery pack 42 and the switching control element 45. In addition, although not shown, in another example of the protection circuit or the charge/discharge device including the switching control element, the protection element 46 may be disposed between the switching control element 45 and the external terminal 44 of the battery pack.
The protection circuit comprising the switching control element and the charging and discharging device can be used for a battery pack. That is, the battery pack including the switching control element according to the present invention is a battery pack of a secondary battery such as a lithium ion battery, and includes: a battery pack 42 in which 1 or more secondary battery cells 41 are connected in series; a signal control unit 43 that outputs a control signal according to the voltage of the cell 41 or the battery pack 42; a switching control element 45 connected to a discharging circuit and a charging circuit between the battery pack 42 and the external terminal 44 of the battery pack, and receiving a signal from the signal control unit 43 to perform on/off control; and a protection element 46 having a fuse block 46-1 and a thermistor 46-2 built therein, the fuse block 46-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 46-2 being controlled by a switching element 48 connected to the signal control section 43; the signal control unit 43 turns off the discharge circuit and turns on the charge circuit at the time of charging, turns on the discharge circuit and turns off the charge circuit at the time of discharging, on/off controls the charge circuit and the discharge circuit, and the protection element 46 blows the fuse element 46-1 to cut off the charge circuit when the value of the current flowing through the charge circuit of the switching control element 45 exceeds a predetermined blowing current value, and the signal control unit 43 causes the thermistor 46-2 to generate heat to blow the fuse element 46-1 to cut off the charge circuit when the cell 41 or the battery pack 42 exceeds a predetermined voltage value.
The battery pack including the switching control element 45 can be used for an electric machine such as a mobile device which does not use an electric wire. That is, the electric device provided with the switching control element according to the present invention is a battery pack using a secondary battery such as a lithium ion battery, and includes: a battery pack 42 in which 1 or more secondary battery cells 41 are connected in series; a battery pack having a protection circuit or a charging/discharging device that controls charging/discharging of the battery pack 42; and a machine body detachably connected to the battery pack, for charging the battery pack or receiving power supply from the battery pack to drive the machine body; the battery pack is provided with: a signal control unit 43 that outputs a control signal according to the voltage of the cell 41 or the battery pack 42; a switching control element 45 connected to a discharging circuit and a charging circuit between the battery pack 42 and the external terminal 44 of the battery pack, and receiving a signal from the signal control unit 43 to perform on/off control; and a protection element 46 having a fuse element 46-1 and a thermistor 46-2 built therein, the fuse element 46-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 46-2 being controlled by a switching element 48 connected to the signal control section 43; the signal control unit 43 turns off the discharge circuit and turns on the charge circuit at the time of charging, turns on the discharge circuit and turns off the charge circuit at the time of discharging, on/off controls the charge circuit and the discharge circuit, and the protection element 46 blows the fuse element 46-1 to cut off the charge circuit when the value of the current flowing through the charge circuit of the switching control element 45 exceeds a predetermined blowing current value, and the signal control unit 43 causes the thermistor 46-2 to generate heat to blow the fuse element 46-1 to cut off the charge circuit when the cell 41 or the battery pack 42 exceeds a predetermined voltage value.
[ examples ]
As shown in fig. 5, the protection circuit 50 of embodiment 1 includes: a battery pack 52 in which 4 cells 51 of lithium ion batteries are connected in series; a signal control unit 53 that outputs a control signal according to the voltage of the cell 51 or the battery pack 52; 1 first switching element 55-1 and 1 second switching element 55-2, which are connected in parallel in a current circuit between the battery pack 52 and the external terminal 54, receive a signal from the signal control section 53 to perform on/off control, and each of which includes an N-channel MOSFET; and 1 protection element 56 in which a fuse unit 56-1 including an fusible metal material and a thermistor 56-2 including a film resistor are built, the fuse unit 56-1 is connected in parallel to the discharge circuit, and the operation of the thermistor 56-2 is controlled by 1 third switching element 55-3 including an N-channel MOSFET connected to the signal control unit 53. The protection circuit 50 is applied to a battery pack charging/discharging device, and the signal control unit 53 controls the charging circuit and the discharging circuit to be turned on/off by turning off the first switching element 55-1 and turning on the second switching element 55-2 during charging and turning on the first switching element 55-1 and turning off the second switching element 55-2 during discharging.
As shown in fig. 6, the protection circuit 60 of embodiment 2 includes: a battery pack 62 in which 4 cells 61 of lithium ion batteries are connected in series; a signal control unit 63 that outputs a control signal according to the voltage of the cell 61 or the battery pack 62; 1 first switching element 65-1 and 1 second switching element 65-2, which are connected in parallel in a current circuit between the battery pack 62 and the external terminal 64, receive a signal from the signal control section 63 to perform on/off control, and each of which includes an N-channel MOSFET; and 1 protection element 66 having a fuse block 66-1 made of an fusible metal material and a thermistor 66-2 made of a film resistor built therein, wherein the fuse block 66-1 is connected in parallel to the discharge circuit, and the operation of the thermistor 66-2 is controlled by 1 third switching element 65-3 made of an N-channel MOSFET connected to the signal control unit 63. The protection circuit 60 is applied to a charging/discharging device of a battery pack, the signal control section 63 branches its signal circuit, and the gate of the first switching element 65-1 is connected to one side thereof, and the gate of the second switching element 65-2 is connected to the other side thereof, and the gate of the second switching element 65-2 is connected to the signal circuit of the signal control section 63 via the inverter element 67. The gate of the first switching element 65-1 is connected to the signal control section 63 without the inverter element 67. Since the second switching element 65-2 has the inverter element 67, it can share a signal circuit with the first switching element 65-1. In embodiment 2, the inverter element 67 is connected to one side of the second switching element 65-2, but the inverter element 67 may be provided on either the first or second switching element, or may be appropriately disposed on one side of the first switching element 65-1 instead of the second switching element 65-2.
As shown in fig. 7, the protection circuit 70 of embodiment 3 includes: a battery pack 72 in which 4 cells 71 of a lithium ion battery are connected in series; a signal control unit 73 that monitors the voltage of the cell 71 or the battery pack 72 and outputs a control signal according to the measurement amount; 1 switching control element 75 which is connected to a discharging circuit and a charging circuit between the battery pack 72 and the external terminal 74 of the battery pack, receives a signal from the signal control section 73, performs on/off control, and includes a CMOS transistor with an inverter (inverting amplifier); and 1 protection element 76 having a fuse block 76-1 made of an fusible metal material and a thermistor 76-2 made of a film resistor built therein, wherein the fuse block 76-1 is connected in parallel to the discharge circuit, and the operation of the thermistor 76-2 is controlled by 1 switching element 78 made of an N-channel MOSFET connected to the signal control unit 73. The protection circuit 70 is applied to a charging/discharging device of a battery pack, the signal control unit 73 is connected to an input terminal (IN) of the switching control element 75, the discharging circuit is connected to a drain of the switching control element 75, and the charging circuit is connected to a source of the switching control element 75 via a fuse element 76-1 of the protection element.
As shown in fig. 8, the protection circuit 80 of embodiment 4 includes: a battery pack 82 in which 4 cells 81 of a lithium ion battery are connected in series; a signal control unit 83 that outputs a control signal according to the voltage of the cell 81 or the battery pack 82; 1 first switching element 85-1 and 1 second switching element 85-2, which are connected in parallel in a current circuit between the battery pack 82 and the external terminal 84, receive a signal from the signal control section 83 to perform on/off control, and include N-channel MOSFETs; 1 protection element 86 having a fuse block 86-1 made of an fusible metal material and a thermistor 86-2 made of a film resistor built therein, the fuse block 86-1 being connected in parallel to the discharge circuit, and the operation of the thermistor 86-2 being controlled by 1 third switching element 85-3 made of an N-channel MOSFET connected to the signal control unit 83; and a delay circuit 89 including a resistance element 89-1 connected in series with the battery pack 82 and a capacitor 89-2 connected to the resistance element 89-1 and connected in parallel with the battery pack 82. The protection circuit 80 can delay the applied voltage by the delay circuit 89 to buffer the inrush current generated in the unit of several μ seconds at the time of switching and apply the same to a charge/discharge device of a battery pack, and the signal control section 83 can turn off the first switching element 85-1 and turn on the second switching element 85-2 at the time of charging, turn on the first switching element 85-1 and turn off the second switching element 85-2 at the time of discharging, and perform on/off control of the charging circuit and the discharging circuit. (refer to FIG. 9)
Further, the protection circuit 80 of embodiment 4 may be modified as the protection circuit 100 shown in fig. 10. Namely, the apparatus is provided with: a battery pack 102 in which 1 or more secondary battery cells 101 are connected in series; a signal control unit 103 that outputs a control signal according to the voltage of the cell 101 or the battery pack 102; a protection element 106 having a fuse element 106-1 and a thermistor 106-2 built therein, the fuse element 106-1 being connected in series to a charge/discharge circuit including 1 path, and the operation of the thermistor 106-2 being controlled by 1 switching element 105 connected to the signal control unit 103; and a delay circuit 109 including a resistance element 109-1 connected in series with the battery pack 102 and a capacitor element 109-2 connected to the resistance element 109-1 and connected in parallel with the battery pack 102; the protection circuit 100 buffers an inrush current at the time of switching by delaying an applied voltage by the delay circuit 89, and cuts off the charge/discharge circuit by blowing the fuse element 106-1 when a value of a current flowing through the charge/discharge circuit exceeds a predetermined blowing current value, and cuts off the charge/discharge circuit by blowing the fuse element 106-1 by heating the thermistor 106-2 by the signal control unit 103 when the cell 101 or the battery pack 102 exceeds a predetermined voltage value.
The switching element of the protection circuit 100 may also include a switching transistor or a protection circuit module including the switching transistor.
The switching element of the protection circuit 100 may also include a FET or a protection circuit module including the FET.
The protection circuit 100 may be applied to a battery pack.
That is, the present invention may be a battery pack of a secondary battery such as a lithium ion battery, including: a battery pack in which 1 or more secondary battery cells are connected in series; a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in series to the charge and discharge circuit, and an operation of the thermistor being controlled by 1 switching element connected to the signal control section; and a delay circuit including a resistance element connected to the battery pack and a capacitor element connected to the resistance element and connected to the battery pack; and the protection circuit is used for delaying the applied voltage through the delay circuit to buffer the inrush current when the switch is switched on, and when the value of the current flowing through the charge and discharge circuit exceeds a preset fusing current value, the fuse component fuses to cut off the charge and discharge circuit, and when the single body or the battery pack exceeds a preset voltage value, the thermistor generates heat through the signal control part to fuse the fuse component, so that the charge and discharge circuit is cut off.
The configuration of the present invention can simplify the protection device by paying attention to overcharge protection in particular, and can contribute to cost reduction of the battery pack and the protection circuit.
(availability in industry)
The present invention is applicable to a protection circuit for an electric or electronic device using a protection element provided with a thermistor and a fuse assembly, and is particularly applicable to a protection device for a secondary battery such as a battery pack.
Description of the reference numerals
10. 20, 30, 40, 50, 60, 70, 80, 100: protective circuit
11. 21, 31, 41, 51, 61, 71, 81, 101: monomer
12. 22, 32, 42, 52, 62, 72, 82, 102: battery pack
13. 23, 33, 43, 53, 63, 73, 83, 103: signal control unit
14. 24, 34, 44, 54, 64, 74, 84, 104: external terminal
15-1, 25-1, 35-1, 55-1, 65-1, 85-1: a first switch element
15-2, 25-2, 35-2, 55-2, 65-2, 85-2: second switch element
15-3, 25-3, 35-3, 55-3, 65-3, 85-3: third switching element
16. 26, 36, 46, 56, 66, 76, 86, 106: protective element
16-1, 26-1, 36-1, 46-1, 56-1, 66-1, 76-1, 86-1, 106-1: fuse assembly
16-2, 26-2, 36-2, 46-2, 56-2, 66-2, 76-2, 86-2, 106-2: thermal resistor
27. 37, 67: inverter element
45. 75: switching control element
48. 78, 105: switching element
89. 109: delay circuit
89-1, 109-1: resistance element
89-2, 109-2: and a capacitor element.

Claims (44)

1. A protection circuit for protecting a battery pack of a secondary battery such as a lithium ion battery from overcharge and overheating, comprising:
a battery pack in which 1 or more secondary battery cells are connected; a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a first switching element and a second switching element connected in parallel to a current circuit between the battery pack and an external terminal, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section.
2. The protection circuit according to claim 1, wherein the first switching element and the second switching element include a switching transistor or a protection circuit module including the switching transistor.
3. The protection circuit according to claim 1 or 2, wherein the first switching element and the second switching element include an FET or a protection circuit module including the FET.
4. The protection circuit according to any one of claims 1 to 3, wherein the first switching element includes 1 switching transistor which is connected to the discharge circuit in such a manner that a bias direction of the internal diode becomes forward with respect to a discharge direction, and
the second switching element includes 1 switching transistor connected to the charging circuit in such a manner that the bias direction of the internal diode is forward with respect to the charging direction.
5. The protection circuit according to any one of claims 1 to 4, wherein the signal control section branches the signal circuits thereof and provides an inverter element in any one of the signal circuits, and connects the gate of the first switching element to one side of the branched signal circuit and the gate of the second switching element to the other side.
6. The protection circuit according to any one of claims 1 to 5, wherein the protection circuit is further provided with a delay circuit including a resistance element and a capacitor element.
7. A charging/discharging device for a battery pack of a secondary battery such as a lithium ion battery, comprising:
a battery pack in which 1 or more secondary battery cells are connected; a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a first switching element and a second switching element connected in parallel to a current circuit between the battery pack and an external terminal, and performing on/off control by receiving a signal from the signal control unit; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section;
the signal control section may turn off the first switching element and turn on the second switching element at the time of charging,
turning on the first switching element and turning off the second switching element at the time of discharge to perform on/off control of a charging circuit and the discharging circuit,
the protection element is provided with the fuse component, the fuse component is fused when the value of the current flowing through the charging circuit of the second switch element exceeds a predetermined fusing current value,
alternatively, the first and second electrodes may be,
when the voltage of the cell or the battery pack exceeds a predetermined voltage value, the thermistor is fused by heat generated by energization.
8. The charging and discharging device according to claim 7, wherein the first switching element and the second switching element include a switching transistor or a protection circuit module including the switching transistor.
9. The charging and discharging device according to claim 7 or 8, wherein the first switching element and the second switching element include an FET or a protection circuit module including the FET.
10. The charging and discharging device according to any one of claims 7 to 9, wherein the first switching element includes 1 switching transistor which is connected to the discharging circuit such that a bias direction of the internal diode becomes forward with respect to a discharging direction, and wherein the switching transistor is connected to the discharging circuit such that a bias direction of the internal diode becomes forward with respect to the discharging direction
The second switching element includes 1 switching transistor connected to the charging circuit in such a manner that the bias direction of the internal diode is forward with respect to the charging direction.
11. The charge and discharge device according to any one of claims 7 to 10, wherein the signal control unit branches the signal circuit thereof, and an inverter element is provided in any one of the signal circuits, and the gate of the first switching element is connected to one side of the branched signal circuit, and the gate of the second switching element is connected to the other side thereof.
12. The charging and discharging device according to any one of claims 7 to 11, wherein the charging and discharging device is further provided with a delay circuit including a resistance element and a capacitor element.
13. A battery pack for a secondary battery such as a lithium ion battery, comprising:
a battery pack in which 1 or more secondary battery cells are connected; a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a first switching element and a second switching element connected in parallel to a current circuit between the battery pack and an external terminal, and performing on/off control by receiving a signal from the signal control unit; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section;
the signal control part
Turning off the first switching element and turning on the second switching element at the time of charging,
the first switching element is turned on and the second switching element is turned off at the time of discharge, and a charging circuit and the discharging circuit are on/off controlled, and
the protective element
The fuse unit is fused to cut off the charging circuit when a value of a current flowing through the charging circuit of the second switching element exceeds a predetermined fusing current value, and the signal control unit causes the thermistor to generate heat to fuse the fuse unit to cut off the charging circuit when the cell or the battery pack exceeds a predetermined voltage value.
14. The battery pack according to claim 13, wherein the first switching element and the second switching element include a switching transistor or a protection circuit module including the switching transistor.
15. The battery pack according to claim 13 or 14, wherein the first switching element and the second switching element include an FET or a protection circuit module including the FET.
16. The battery pack according to any one of claims 13 to 15, wherein the first switching element includes 1 switching transistor that is connected to the discharge circuit in such a manner that a bias direction of the internal diode becomes forward with respect to a discharge direction, and
the second switching element includes 1 switching transistor connected to the charging circuit in such a manner that the bias direction of the internal diode is forward with respect to the charging direction.
17. The battery pack according to any one of claims 13 to 16, wherein the signal control section branches the signal circuit thereof and provides an inverter element in any one of the signal circuits, and the gate of the first switching element is connected to one side of the branched signal circuit and the gate of the second switching element is connected to the other side.
18. A battery pack, as recited in any one of claims 13 to 17, wherein the battery pack is further provided with a delay circuit including a resistance element and a capacitor element.
19. An electric machine using a battery pack of secondary batteries such as lithium ion batteries, comprising:
a battery pack in which 1 or more secondary battery cells are connected; a battery pack having a protection circuit or a charging/discharging device for controlling charging/discharging of the battery pack; and a machine main body which is detachably connected to the battery pack, and which is driven by charging the battery pack or receiving power supply from the battery pack;
the battery pack is provided with:
a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a first switching element and a second switching element connected in parallel to a current circuit between the battery pack and an external terminal, and performing on/off control by receiving a signal from the signal control unit; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a third switching element connected to the signal control section;
the signal control part
Turning off the first switching element and turning on the second switching element at the time of charging,
the first switching element is turned on and the second switching element is turned off at the time of discharge, and a charging circuit and the discharging circuit are on/off controlled, and
the protective element
When the value of the current flowing through the charging circuit of the second switching element exceeds a predetermined fusing current value, a fuse element fuses to cut off the charging circuit, and when the cell or the battery pack exceeds a predetermined voltage value, the signal control unit causes the thermistor to generate heat and the fuse element fuses to cut off the charging circuit.
20. The electric machine of claim 19, wherein the first and second switching elements comprise switching transistors or protection circuit modules including the switching transistors.
21. The electric machine according to claim 19 or 20, wherein the first switching element and the second switching element include an FET or a protection circuit module including the FET.
22. The electric machine according to any one of claims 19 to 21, wherein the first switching element includes 1 switching transistor connected to the discharge circuit in such a manner that a bias direction of the internal diode becomes forward with respect to a discharge direction, and
the second switching element includes 1 switching transistor connected to the charging circuit in such a manner that the bias direction of the internal diode is forward with respect to the charging direction.
23. The electric machine according to any one of claims 19 to 22, wherein the signal control section branches the signal circuit thereof and provides an inverter element in any one of the signal circuits, and the gate of the first switching element is connected to one side of the branched signal circuit and the gate of the second switching element is connected to the other side.
24. An electrical machine as claimed in any of claims 19 to 23, wherein the electrical machine is further provided with a delay circuit comprising a resistive element and a capacitor element.
25. A protection circuit for protecting a battery pack of a secondary battery such as a lithium ion battery from overcharge and overheating, comprising:
a battery pack formed by connecting more than 1 single body; a signal control unit that monitors the voltage of the cell or the battery pack and outputs a control signal according to a measurement amount thereof; a switching control element connected to a discharging circuit and a charging circuit between the battery pack and an external terminal of a battery pack, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a switching element connected to the signal control section.
26. The protection circuit of claim 25, wherein the switching control element comprises a switching element selected from the group of a selector, a switching controller, a CMOS transistor, a FET, or a protection circuit module including the switching element.
27. The protection circuit according to claim 25 or 26, wherein the protection circuit is further provided with a delay circuit including a resistance element and a capacitor element.
28. A charging/discharging device for a battery pack of a secondary battery such as a lithium ion battery, comprising:
a battery pack formed by connecting more than 1 single body; a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a switching control element connected to a discharging circuit and a charging circuit between the battery pack and an external terminal of a battery pack, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a switching element connected to the signal control section;
the switching control element is capable of turning off the discharge circuit and turning on the charge circuit by the signal control section at the time of charging,
the signal control part turns on the discharge circuit and turns off the charge circuit during discharge, and the charge circuit and the discharge circuit are controlled to be turned on/off, and
the protection element has the fuse component which is blown when the value of the current flowing through the charging circuit of the switching control element exceeds a given blowing current value,
or the thermistor is fused by heat generated by energization when the voltage of the cell or the battery pack exceeds a predetermined voltage value.
29. The charging and discharging device according to claim 28, wherein the switching control element comprises a switching element selected from a group of a selector, a switching controller, a CMOS transistor, an FET, or a protection circuit module including the switching element.
30. The charging and discharging device according to claim 28 or 29, wherein the charging and discharging device is further provided with a delay circuit including a resistance element and a capacitor element.
31. A battery pack for a secondary battery such as a lithium ion battery, comprising:
a battery pack in which 1 or more secondary battery cells are connected; a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a switching control element connected to a discharging circuit and a charging circuit between the battery pack and an external terminal of a battery pack, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a switching element connected to the signal control section;
the signal control part
The discharge circuit is turned off and the charge circuit is turned on at the time of charging,
the discharge circuit is turned on and the charge circuit is turned off at the time of discharge, and the charge circuit and the discharge circuit are on/off controlled, and
the protective element
When the value of the current flowing through the charging circuit of the switching control element exceeds a predetermined fusing current value, the fuse element fuses to cut off the charging circuit, and when the cell or the battery pack exceeds a predetermined voltage value, the signal control unit causes the thermistor to generate heat and the fuse element fuses to cut off the charging circuit.
32. The battery pack according to claim 31, wherein the switching control element includes a switching element selected from a group of a selector, a switching controller, a CMOS transistor, a FET, or a protection circuit module including the switching element.
33. The battery pack according to claim 31 or 32, wherein the switching control element includes an inverter-equipped switching element or a protection circuit module including the inverter-equipped switching element.
34. A battery pack, as recited in any one of claims 31 to 33, wherein the battery pack is further provided with a delay circuit including a resistive element and a capacitor element.
35. An electric machine using a battery pack of secondary batteries such as lithium ion batteries, comprising:
a battery pack in which 1 or more secondary battery cells are connected; a battery pack having a protection circuit or a charging/discharging device for controlling charging/discharging of the battery pack; and a machine main body which is detachably connected to the battery pack, and which is driven by charging the battery pack or receiving power supply from the battery pack;
the battery pack is provided with:
a signal control unit for outputting a control signal according to the voltage of the cell or the battery pack; a switching control element connected to a discharging circuit and a charging circuit between the battery pack and an external terminal of the battery pack, and receiving a signal from the signal control unit to perform on/off control; and a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in parallel to the discharge circuit, and an operation of the thermistor being controlled by a switching element connected to the signal control section;
the signal control part
The discharge circuit is turned off and the charge circuit is turned on at the time of charging,
the discharge circuit is turned on and the charge circuit is turned off at the time of discharge, and the charge circuit and the discharge circuit are on/off controlled, and
the protective element
When the value of the current flowing through the charging circuit of the switching control element exceeds a predetermined fusing current value, the fuse element fuses to cut off the charging circuit, and when the cell or the battery pack exceeds a predetermined voltage value, the signal control unit causes the thermistor to generate heat and the fuse element fuses to cut off the charging circuit.
36. The electrical machine of claim 35, wherein the switching control element comprises a switching element selected from the group of a selector, a switching controller, a CMOS transistor, a FET, or a protection circuit module including the switching element.
37. An electric machine as claimed in claim 35 or 36, wherein the switching control element comprises an inverter-equipped switching element or a protection circuit module including the inverter-equipped switching element.
38. An electrical machine as claimed in any of claims 35 to 37, wherein the electrical machine is further provided with a delay circuit comprising a resistive element and a capacitor element.
39. A protection circuit for protecting a battery pack of a secondary battery such as a lithium ion battery from overcharge and overheating, comprising:
a battery pack in which 1 or more secondary battery cells are connected in series; a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in series to the charge and discharge circuit, and an operation of the thermistor being controlled by 1 switching element connected to the signal control section; and a delay circuit including a resistance element connected to the battery pack and a capacitor element connected to the resistance element and connected to the battery pack.
40. The protection circuit of claim 39, wherein the switching element comprises a switching transistor or a protection circuit module including the switching transistor.
41. The protection circuit according to claim 39 or 40, wherein the switching element comprises a FET or a protection circuit module including the FET.
42. A battery pack for a secondary battery such as a lithium ion battery, comprising:
a battery pack in which 1 or more secondary battery cells are connected in series; a signal control unit that outputs a control signal according to a voltage of the cell or the battery pack; a protection element having a fuse assembly and a thermistor built therein, the fuse assembly being connected in series to the charge and discharge circuit, and an operation of the thermistor being controlled by 1 switching element connected to the signal control section; and a delay circuit including a resistance element connected to the battery pack and a capacitor element connected to the resistance element and connected to the battery pack; and is
The protection circuit buffers inrush current when a switch is switched by delaying an applied voltage by the delay circuit, and cuts off the charge/discharge circuit by fusing the fuse element when a value of current flowing through the charge/discharge circuit exceeds a predetermined fusing current value, and cuts off the charge/discharge circuit by the signal control unit by fusing the fuse element by heating the thermistor when the cell or the battery pack exceeds a predetermined voltage value.
43. The battery pack according to claim 42, wherein the switching element includes a switching transistor or a protection circuit module including the switching transistor.
44. The battery pack according to claim 42 or 43, wherein the switching element includes an FET or a protection circuit module including the FET.
CN202110673991.XA 2020-06-17 2021-06-17 Protective circuit Pending CN113809788A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2020-104844 2020-06-17
JP2020104844 2020-06-17
JP2021092895A JP7421516B2 (en) 2020-06-17 2021-06-02 protection circuit
JP2021-092895 2021-06-02

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Publication number Priority date Publication date Assignee Title
JP4207877B2 (en) * 2004-10-04 2009-01-14 ソニーケミカル＆インフォメーションデバイス株式会社 Protection circuit
JP5250230B2 (en) * 2007-09-28 2013-07-31 株式会社日立製作所 Power supply system for vehicle and integrated circuit for battery cell control
CN204407869U (en) * 2014-12-15 2015-06-17 东莞市百维科技有限公司 Lithium battery secondary overvoltage protective circuit and lithium battery protection circuit
TW201640769A (en) * 2015-05-11 2016-11-16 Pao-Hsuan Chen Multifunctional protection element, protection circuit and secondary battery pack of multiple current loops
JPWO2020136862A1 (en) * 2018-12-28 2021-11-11 ボーンズ株式会社 Secondary battery circuit and its control method

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