CN211579584U

CN211579584U - Lithium battery management system short-circuit protection circuit and device thereof

Info

Publication number: CN211579584U
Application number: CN201922322935.2U
Authority: CN
Inventors: 李云星
Original assignee: Hangzhou Lide Communication Co ltd
Current assignee: Hangzhou Lide Communication Co ltd
Priority date: 2019-12-20
Filing date: 2019-12-20
Publication date: 2020-09-25
Anticipated expiration: 2029-12-20

Abstract

The utility model discloses a lithium battery management system short-circuit protection circuit, which enables a control IC to stop outputting pulse width modulation signals when the output end of a power supply with the control IC for outputting the pulse width modulation signals generates short circuit, and comprises a short-circuit protection module which is connected with an IC output end U0; the utility model discloses the short circuit appears at the output, and short circuit output reaches when the minvalue of primary side overpower, the voltage that is used for at the primary coil T1 both ends for controlling worker C0 power supply of transformer begins to descend, from this, via resistance R3, the voltage decline of the power end VCC who directly supplies with control worker C0 behind rectifier diode D1 and the smooth electric capacity C0, when the power end VCC descends to by the below the minvalue of control worker C regulation, the inside short-circuit protection function work of control worker C0, stop outputting the PWM signal, the power does not export, short-circuit protection module work simultaneously, have dual short-circuit protection function.

Description

Lithium battery management system short-circuit protection circuit and device thereof

Technical Field

The utility model relates to a lithium battery management system technical field specifically is a lithium battery management system short-circuit protection circuit and device thereof.

Background

The battery management system is a system for managing a battery, and generally has a function of measuring a battery voltage, and prevents or avoids abnormal situations such as overdischarge, overcharge, and an excess temperature … of the battery. As technology has evolved, many functions have been gradually added.

The target is usually a rechargeable secondary battery, and in recent years, many batteries are used together with a lithium ion battery pack. The power management system is similar to the BMS, but the BMS manages the battery, and the EMS summarizes the management of all the energy sources;

the lithium battery is a primary battery using lithium metal or lithium alloy as a negative electrode material and using a non-aqueous electrolyte solution, unlike a lithium ion battery, which is a rechargeable battery, and a lithium ion polymer battery. The utility model of a lithium battery is edison. Because the chemical characteristics of lithium metal are very active, the requirements on the environment for processing, storing and using the lithium metal are very high. Therefore, lithium batteries have not been used for a long time. With the development of microelectronic technology at the end of the twentieth century, miniaturized devices are increasing, and high requirements are made on power supplies. The lithium battery enters a large-scale practical stage;

present lithium battery management system requires more and more highly, especially need carry out short-circuit protection, and then traditional short-circuit protection effect is poor, for this reason, utility model people synthesizes all kinds of factors and has proposed a lithium battery management system short-circuit protection circuit and device thereof.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a lithium battery management system short-circuit protection circuit and device to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

a short-circuit protection circuit of lithium battery management system, which makes a control IC stop outputting pulse width modulation signals when the output end of a power supply with the control IC for outputting pulse width modulation signals generates short circuit, comprises a short-circuit protection module connected with an IC output end U₀The short-circuit protection module comprises a voltage regulator tube V, a resistor R4 and a resistor R5, wherein the voltage regulator tube, the resistor R4 and the resistor R5 are sequentially arranged at the output end U of the IC₀The two ends of the R4 are connected in parallel with an optical coupler OT, two

pins

1 and 2 of the optical coupler are connected with the two ends of the R4, and two

pins

3 and 4 of the optical coupler are respectively connected with a resistor R7 and a resistor R6 and are grounded through R7; the outer end of the resistor 6 is connected with a reference voltage VREF.

As a further aspect of the present invention: two ends of the R7 are connected with an R8 and a triode Q in parallel and are grounded through the triode Q;

as a further aspect of the present invention: a capacitor C is connected between the collector and the emitter of the triode Q;

as a further aspect of the present invention: and the base electrode of the triode Q is connected with a pin 1 of UC 3842.

As a further aspect of the present invention: the IC output end U₀The capacitor C0 is connected with the diodes D1 and R3 in parallel at two ends through the capacitor C0 to be grounded.

Compared with the prior art, the utility model discloses the beneficial effect of following several aspects has:

when a short circuit occurs at the output end and the short-circuit output power reaches the threshold value of the primary side overpower, the voltage at two ends of a primary coil T1 of the transformer for supplying power to a control worker C0 begins to drop, so that the voltage of a power supply end VCC directly supplied to the control worker C0 after passing through a resistor R3, a rectifier diode D1 and a smoothing capacitor C0 drops, when the voltage of the power supply end VCC drops below the threshold value specified by the control worker C, a short-circuit protection function inside the control worker C0 works, the PWM signal is stopped to be output, the power supply does not output, and meanwhile, a short-circuit protection module works during short circuit, U₀The end current passes through a large voltage regulator tube to be broken down and conducted, and generates current flow through the optical coupler OT to ground, and a light emitting diode of the photoelectric coupler emits light, so that a phototriode of the photoelectric coupler is conducted; the Q base electrode is electrified and conducted, the power of pin 1 of 3842 is reduced, the IC is closed, the work of the whole power supply is stopped, and the double short-circuit protection function is achieved.

Drawings

Fig. 1 is a schematic structural diagram of a short-circuit protection circuit of a lithium battery management system and a device thereof.

Fig. 2 is a schematic structural diagram of a short-circuit protection circuit of a lithium battery management system and a short-circuit protection module in the lithium battery management system.

Detailed Description

The technical solution of the present patent will be described in further detail with reference to the following embodiments.

Referring to fig. 1-2, a short-circuit protection circuit of a lithium battery management system, which enables a control IC to stop outputting a pulse width modulation signal when an output terminal of a power supply of the control IC for outputting the pulse width modulation signal is short-circuited, includes a short-circuit protection module, the short-circuit protection module is connected to an IC output terminal U0, the short-circuit protection module includes a voltage regulator V, a resistor R4 and a resistor R5, the voltage regulator, the resistor R4 and the resistor R5 are sequentially connected to an IC output terminal U0 in parallel and grounded, two ends of R4 are connected in parallel with an optocoupler OT, two

pins

1 and 2 of the optocoupler are connected to two ends of R4, and two

pins

3 and 4 of the optocoupler are respectively connected to a resistor R7 and a resistor R6 and grounded through R7; the outer end of the resistor 6 is connected with a reference voltage VREF.

Two ends of the R7 are connected with an R8 and a triode Q in parallel and are grounded through the triode Q;

a capacitor C is connected between the collector and the emitter of the triode Q;

and the base electrode of the triode Q is connected with a pin 1 of UC 3842.

The IC output terminal U0 is grounded through a capacitor C0, and a diode D1 and a diode R3 are connected in parallel to two ends of the capacitor C0.

The utility model discloses a theory of operation is: when a short circuit occurs at the output end and the short-circuit output power reaches the threshold value of the primary side overpower, the voltage at two ends of a primary coil T1 of the transformer for supplying power to a control worker C starts to drop, so that the voltage directly supplied to a power supply end VCC of the control worker C0 via a resistor R3, a rectifier diode D1 and a smoothing capacitor C0 drops, when the power supply end VCC drops below the threshold value specified by the control worker C, a short-circuit protection function inside the control worker C0 works, the output of a PWM signal is stopped, the power supply does not output, and meanwhile, a short-circuit protection module works during short circuit, U₀The end current passes through a large voltage regulator tube to be broken down and conducted, and generates current flow through the optical coupler OT to ground, and a light emitting diode of the photoelectric coupler emits light, so that a phototriode of the photoelectric coupler is conducted; the Q base is electrically conducted, and the 1 pin of 3842 is electrifiedAnd the voltage is reduced, so that the IC is closed, the work of the whole power supply is stopped, and the double short-circuit protection function is realized.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

Although the preferred embodiments of the present patent have been described in detail, the present patent is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present patent within the knowledge of those skilled in the art.

Claims

1. A lithium battery management system short-circuit protection circuit is characterized by comprising a short-circuit protection module, wherein the short-circuit protection module is connected to an IC output end U0 and comprises a voltage-stabilizing tube V, a resistor R4 and a resistor R5, the voltage-stabilizing tube, the resistor R4 and the resistor R5 are sequentially connected to an IC output end U0 in parallel and are grounded, two ends of R4 are connected with an optical coupler OT in parallel, two pins 1 and 2 of the optical coupler are connected to two ends of R4, and two pins 3 and 4 of the optical coupler are respectively connected with the resistor R7 and the resistor R6 and are grounded through the R7; the outer end of the resistor 6 is connected with a reference voltage VREF.

2. The short-circuit protection circuit of lithium battery management system as claimed in claim 1, wherein the R7 has two ends connected in parallel with R8 and transistor Q, and is grounded through transistor Q.

3. The short-circuit protection circuit of lithium battery management system as claimed in claim 2, wherein a capacitor C is connected between the collector and the emitter of the transistor Q.

4. The short-circuit protection circuit of lithium battery management system as claimed in claim 3, wherein the base of the transistor Q is connected to the 1 pin of UC 3842.

5. The short-circuit protection circuit of a lithium battery management system as claimed in any one of claims 1 to 4, wherein the IC output terminal U0 is grounded through a capacitor C0, and diodes D1 and R3 are connected in parallel across the capacitor C0.

6. A wiring device using the short-circuit protection circuit for a lithium battery management system according to claim 5.