Battery protection circuit and energy storage power supply

Abstract

The embodiment of the utility model discloses a battery protection circuit and an energy storage power supply, the circuit comprises a comparative judgment module, a latch protection module and a latch release module, the comparative judgment module is electrically connected with a battery, and the latch protection module is electrically connected with the comparative judgment module and the latch release module respectively; the comparison and judgment module is used for receiving a current sampling signal of the battery and outputting a trigger signal when the current sampling signal exceeds a preset reference voltage; the latch protection module is used for adjusting the level states of the overcurrent protection signal and the discharge control signal according to the trigger signal; and the latch release module is used for receiving an external control signal and recovering the level states of the overcurrent protection signal and the discharge control signal according to the external control signal. According to the embodiment of the utility model, the trigger signal is output when the current exceeds the preset threshold value, so that the latch protection module adjusts the level states of the over-current protection signal and the discharge control signal to realize over-current protection. Response time can be shortened, reliability of the protection circuit is improved, and cost is reduced.

Description

TECHNICAL FIELD

[0001] The embodiment of the utility model relates to the field of battery protection, in particular to a battery protection circuit and energy storage power supply. BACKGROUND

[0002] The traditional battery overcurrent or short circuit protection circuit is all software protection, specifically, MCU realizes overcurrent and short circuit detection through software program, MCU collects current sampling signals, compares with preset threshold value, when detecting overcurrent or short circuit, MCU controls MOS pipe to shut off.

[0003] This kind of scheme has the following defects: response time is long, can not cut off current in time when overcurrent is serious, and has no interlock function, and after triggering overcurrent or short circuit protection, can only restart to clear fault. UTILITY MODEL CONTENT

[0004] The embodiment of the utility model mainly solves the technical problem of providing a battery protection circuit and energy storage power supply, which can solve the defects of the existing battery overcurrent protection scheme.

[0005] In order to solve the above technical problems, one of the technical schemes of the utility model is: a battery protection circuit is provided, comprising: comparison judgment module, latching protection module and latching release module, the comparison judgment module and the battery are connected, the latching protection module is connected with the comparison judgment module and the latching release module respectively; the comparison judgment module is used for receiving the current sampling signal of the battery, and outputting a trigger signal when the current sampling signal exceeds a preset reference voltage; the latching protection module is used for adjusting the level state of overcurrent protection signal and discharge control signal according to the trigger signal; wherein, the overcurrent protection signal is used for indicating overcurrent state, and the discharge control signal is used for controlling the conduction state of discharge switch tube; the latching release module is used for receiving external control signal and restoring the level state of the overcurrent protection signal and the discharge control signal according to the external control signal.

[0006] In some embodiments, when the voltage value of the current sampling signal is greater than the preset threshold value, the latching protection module pulls the overcurrent protection signal and the discharge control signal from high level state to low level state;When the latching release module receives the external control signal, stop adjusting the level state of the overcurrent protection signal and the discharge control signal.

[0007] In some embodiments, the latching protection module includes a transistor Q2 and a transistor Q3, when the trigger signal is high, the transistor Q2 receives the trigger signal and turns on, and provides current to drive the transistor Q3 to turn on;The transistor Q3 turns on and provides base current for the transistor Q2 through the collector.

[0008] In some embodiments, the latch protection module further comprises resistors R1, R2, R3, R4, R5, R6, diodes D2, D3 and a power supply V2, a first end of the resistor R1 and a first end of the resistor R2 and a positive pole of the power supply V2 are connected, a second end of the resistor R1 and an emitter of the triode Q3 are connected, a base of the triode Q3 and a first end of the resistor R3 are connected, a collector of the triode Q3 and a first end of the resistor R4, a first end of the resistor R6, a first end of the resistor R5, a base of the triode Q2 and an output of the comparison judging module are connected; a second end of the resistor R2 and a collector of the triode Q2, a second end of the resistor R3, a cathode of the diode D2 and a cathode of the diode D3 are connected, an anode of the diode D2 and the overcurrent protection signal are connected, an anode of the diode D3 and the discharge control signal are connected; a negative pole of the power supply V2, an emitter of the triode Q2, a second end of the resistor R6 and a second end of the resistor R5 are grounded.

[0009] In some embodiments, the latch release module comprises a triode Q1, a resistor R8 and a resistor R9, a first end of the resistor R8 and a base of the triode Q1 and a first end of the resistor R9 are connected, a collector of the triode Q1 and an input of the latch protection module are connected, an emitter of the triode Q1, a second end of the resistor R8 and a second end of the resistor R9 are grounded.

[0010] In some embodiments, when the external control signal is high: the triode Q1 is turned on and the base potential of the triode Q2 is lowered; the triode Q1 is turned off, cutting off the base current of the triode Q3, so that the triode Q3 is turned off.

[0011] In some embodiments, the comparison judging module comprises a reference unit and a comparison unit, the comparison unit is connected with the reference unit and a current sampling signal respectively; the reference unit is used to generate the preset reference voltage; the comparison unit is used to output the trigger signal when the current sampling signal exceeds the preset reference voltage.

[0012] In some embodiments, the reference unit comprises a power supply V3, a resistor R10 and a resistor R11, a positive pole of the power supply V3 and a first end of the resistor R10 are connected, a second end of the resistor R10 and an input of the comparison unit and a first end of the resistor R11 are connected, a second end of the resistor R11 and a negative pole of the power supply V3 are grounded.

[0013] In some embodiments, the comparison unit comprises a comparator U1A, a resistor R7, a power supply V1 and a diode D1, the non-inverting input terminal of the comparator U1A is connected with the positive pole of the battery, the inverting input terminal of the comparator U1A is connected with the output terminal of the reference unit, the first power input terminal of the comparator U1A is connected with the positive pole of the power supply V1 and the second terminal of the resistor R7, the output terminal of the comparator U1A is connected with the first terminal of the resistor R7 and the anode of the diode D1, the cathode of the diode D1 is connected with the input terminal of the latch protection module, the second power input terminal of the comparator U1A, the negative pole of the power supply V1 and the negative pole of the battery are grounded.

[0014] To solve the above technical problems, the utility model adopts another technical scheme, which provides a battery protection circuit, which comprises the following components.

[0015] The utility model embodiment has the advantages that, unlike the prior art, the utility model embodiment outputs a trigger signal when the current exceeds the preset threshold value, so that the latch protection module forms a self-maintaining conduction state, and the level state of the overcurrent protection signal and the discharge control signal is adjusted to realize overcurrent protection. The response time is shortened, the reliability of the protection circuit is improved, and the cost is reduced. The latch release module is arranged to restore the overcurrent protection signal and the discharge control signal by an external control signal, so that the necessity of restarting to clear faults is avoided, and the flexibility of the protection circuit is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of a battery protection circuit provided by the utility model embodiment;

[0017] Figure 2 is a circuit principle diagram of a battery protection circuit provided by the utility model embodiment; DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of the utility model, the utility model will be described in more detail below in combination with the drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element or one or more intervening elements can be present therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element or one or more intervening elements can be present therebetween. The terms "vertical", "horizontal", "left", "right" and similar expressions used in the specification are only for the purpose of illustration.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. The use herein of "and / or" means any one or all possible combinations of one or more of the associated listed items.

[0020] To solve the problems of long response time, no interlock function and only clearing fault by restarting in the existing battery overcurrent protection scheme, the application provides a battery protection circuit, a structural diagram of which is shown in Figure 1 The battery protection circuit 10 includes a comparison and judgment module 110, a latch protection module 120 and a latch release module 130. The input end of the comparison and judgment module 110 is electrically connected with the output end of the battery 20, the output end of the comparison and judgment module 110 and the output end of the latch release module 130 are connected with the input end of the latch protection module 120, and the output end of the latch protection module 120 is connected with an overcurrent protection signal and a discharge control signal.

[0021] The comparison and judgment module 110 is used for receiving the current sampling signal of the battery 20 and outputting a trigger signal when the current sampling signal exceeds a preset reference voltage. The latch protection module 120 is used for adjusting the level state of the overcurrent protection signal and the discharge control signal according to the trigger signal, wherein the overcurrent protection signal is used for indicating an overcurrent state, and the discharge control signal is used for controlling the conduction state of a discharge switch tube. The latch release module 130 is used for receiving an external control signal and restoring the level state of the overcurrent protection signal and the discharge control signal according to the external control signal.

[0022] In some embodiments of the application, the external control signal can be a digital control signal generated by an MCU. In actual application, when the overcurrent fault triggers protection, the MCU can judge whether the condition of releasing the overcurrent protection is met according to the demand of the specific application scene by evaluating the load state and the system working state and the like. If the condition is met, the MCU outputs a high-level external control signal for releasing the overcurrent protection state. The level of the external control signal can be a digital signal level of 3.3V or 5V, which depends on the power voltage of the system.

[0023] The overcurrent protection signal is a state indication signal, which is used for feeding back the overcurrent protection state of the current circuit to the MCU. In the normal working state, the overcurrent protection signal keeps high level; when the overcurrent protection occurs, the overcurrent protection signal is pulled down to low level. The MCU can collect the signal to monitor the overcurrent protection state of the circuit in real time, and execute the corresponding control strategy or fault processing flow according to the need.

[0024] The discharge control signal is used to directly control the on-off state of the power switch tube (such as MOSFET) in the battery discharge circuit. The signal is usually connected to the gate drive circuit of the MOSFET. In the normal working state, the discharge control signal keeps high level, so that the discharge switch tube is turned on and the battery is allowed to discharge; when the overcurrent protection is triggered, the discharge control signal is pulled low to low level, so that the discharge switch tube is turned off and the discharge current is cut off. The level value of the discharge control signal needs to meet the gate drive requirements of the MOSFET used, and the level value is usually 10-15V.

[0025] Specifically, when the voltage value of the current sampling signal is greater than the preset threshold, the latch protection module 120 pulls the overcurrent protection signal and the discharge control signal from the high level state to the low level state; when the latch release module 130 receives the external control signal, the level state of the overcurrent protection signal and the discharge control signal is stopped.

[0026] In the embodiments of the present application, when the battery is in the normal working state, that is, the voltage value of the current sampling signal is not greater than the preset threshold, the overcurrent protection signal is high, indicating that there is no overcurrent fault; the discharge control signal is high, and the discharge switch tube is turned on; the external control signal is low, and is waiting for use; when the battery overflows, that is, the voltage value of the current sampling signal is greater than the preset threshold, the latch protection module 120 acts; the overcurrent protection signal flips to low level, reporting the fault to the MCU; the discharge control signal flips to low level, turning off the discharge switch tube; the MCU receives the overcurrent protection signal, records the fault information; when the MCU judges that the protection can be released, the MCU outputs the external control signal with high level; the latch release module 130 acts, releasing the self-locking state of the latch protection module 120; the overcurrent protection signal and the discharge control signal return to high level; the battery protection circuit returns to the normal working state.

[0027] In some embodiments of the present application, the latch protection module 120 includes a transistor Q2 and a transistor Q3. When the trigger signal is high, the transistor Q2 receives the trigger signal to turn on and provides current to drive the transistor Q3 to turn on; after the transistor Q3 turns on, it provides base current for the transistor Q2 through the collector, forming a self-locking state.

[0028] In some embodiments of the present application, the specific circuit structure of the latch protection module 120 is as follows: Figure 2As shown, it further comprises resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, diode D2, diode D3 and power supply V2. The first end of resistor R1 and the first end of resistor R2 and the positive pole of power supply V2 are connected, the second end of resistor R1 and the emitter of triode Q3 are connected, the base of triode Q3 and the first end of resistor R3 are connected, the collector of triode Q3 and the first end of resistor R4, the first end of resistor R6, the first end of resistor R5, the base of triode Q2 and the output end of comparison judging module 110 are connected.

[0029] The second end of resistor R2 and the collector of triode Q2, the second end of resistor R3, the cathode of diode D2 and the cathode of diode D3 are connected, the anode of diode D2 and the overcurrent protection signal are connected, the anode of diode D3 and the discharge control signal are connected; the negative pole of power supply V2, the emitter of triode Q2, the second end of resistor R6 and the second end of resistor R5 are grounded.

[0030] In some embodiments of the present application, the latch release module 130 comprises triode Q1, resistor R8 and resistor R9. The first end of resistor R8 and the base of triode Q1 and the first end of resistor R9 are connected, the collector of triode Q1 and the input end of latch protection module 120 are connected, the emitter of triode Q1, the second end of resistor R8 and the second end of resistor R9 are grounded.

[0031] Specifically, when the external control signal is high, triode Q1 is turned on and the base potential of triode Q2 is lowered; triode Q1 is turned off, cutting off the base current of triode Q3, so that triode Q3 is turned off, thereby releasing the lock state.

[0032] In some embodiments of the present application, the comparison judging module 110 comprises reference unit 111 and comparison unit 112. The comparison unit 112 is connected with the reference unit 111 and the current sampling signal respectively. The reference unit 111 is used to generate a preset reference voltage; the comparison unit 112 is used to output a trigger signal when the current sampling signal exceeds the preset reference voltage.

[0033] In some embodiments of the present application, the reference unit 111 comprises power supply V3, resistor R10 and resistor R11. The positive pole of power supply V3 and the first end of resistor R10 are connected, the second end of resistor R10 and the input end of comparison unit 112 and the first end of resistor R11 are connected, the second end of resistor R11 and the negative pole of power supply V3 are grounded.

[0034] In some embodiments of the application, the comparison unit 112 includes a comparator U1A, a resistor R7, a power supply V1 and a diode D1. The non-inverting input terminal of the comparator U1A is connected to the positive pole of the battery 20, the inverting input terminal of the comparator U1A is connected to the output terminal of the reference unit 111, the first power input terminal of the comparator U1A is connected to the positive pole of the power supply V1 and the second terminal of the resistor R7, the output terminal of the comparator U1A is connected to the first terminal of the resistor R7 and the anode of the diode D1, the cathode of the diode D1 is connected to the input terminal of the latch protection module 120, and the second power input terminal of the comparator U1A, the negative pole of the power supply V1 and the negative pole of the battery 20 are grounded.

[0035] The specific working principle is as follows: in the normal working state of the circuit, the voltage V4 at the non-inverting input terminal of the comparator U1A is less than the reference voltage V3 at the inverting input terminal, the comparator U1A outputs a low level, and the transistor Q2 is not turned on. When the voltage V4 corresponding to the battery current is higher than the reference voltage V3, the output of the comparator U1A flips to a high level, the base voltage of the transistor Q2 is greater than the conduction threshold and the transistor Q2 is turned on. At this time, the cathode potential of the diode D2 and the diode D3 is pulled down to the ground potential, the discharge switch tube is closed, and the overcurrent protection signal is pulled down to indicate the overcurrent fault state. The base voltage of the transistor Q3 is also greater than the conduction threshold and the transistor Q3 is turned on, at this time the transistors Q2 and Q3 are in a mutual locking state.

[0036] When receiving an external high-level control signal, the transistor Q1 is turned on, the base potential of the transistor Q2 is reduced to below the conduction threshold and the transistor Q2 is turned off, the discharge switch tube drive signal and the overcurrent protection signal return to a high level. At the same time, the base potential of the transistor Q3 is also reduced to below the conduction threshold and the transistor Q3 is turned off, the transistors Q2 and Q3 are in a mutual locking state, and the circuit returns to a normal working state.

[0037] Different from the prior art, the embodiment of the utility model through setting comparison judgment module, latch protection module and latch release module, when current exceeds preset threshold, output trigger signal, to make latch protection module form self-sustaining conduction state, adjust overcurrent protection signal and discharge control signal level state realize overcurrent protection. This scheme can shorten the response time, improve the reliability of the protection circuit and reduce the cost. And set up the latch release module, can restore overcurrent protection signal and discharge control signal through external control signal, avoid the necessity of restarting to clear the fault, improve the flexibility of the protection circuit.

[0038] Based on the battery protection circuit provided in the above embodiment, the embodiment of the application further provides a energy storage power supply, which comprises the battery protection circuit as described in the above embodiment.

[0039] It should be noted that the description and drawings of the utility model give the preferred embodiments of the utility model, however, the utility model can be realized through many different forms, and is not limited to the embodiments described in the description, the embodiments are not as additional limitation to the content of the utility model, the purpose of providing the embodiments is to make the understanding of the disclosure of the utility model more thorough and comprehensive. Furthermore, the above technical features continue to combine, form various embodiments not listed above, which are considered as the range of the description of the utility model; further, for those skilled in the art, the above description can be improved or transformed, and all these improvements and transformations should belong to the protection scope of the utility model claims.

Claims

1. A battery protection circuit, characterized by, The circuit comprises a comparison judging module, a latch protection module and a latch release module, the comparison judging module is electrically connected with the battery, the latch protection module is electrically connected with the comparison judging module and the latch release module respectively; The comparison judging module is used for receiving a current sampling signal of the battery, and outputting a trigger signal when the current sampling signal exceeds a preset reference voltage; The latch protection module is used for adjusting a level state of an overcurrent protection signal and a discharge control signal according to the trigger signal, wherein the overcurrent protection signal is used for indicating an overcurrent state, and the discharge control signal is used for controlling a conduction state of a discharge switch tube; The latch release module is used for receiving an external control signal and restoring the level state of the overcurrent protection signal and the discharge control signal according to the external control signal.

2. The circuit according to claim 1, wherein when a voltage value of the current sampling signal is greater than a preset threshold value, the latch protection module pulls the overcurrent protection signal and the discharge control signal from a high level state to a low level state; when the latch release module receives the external control signal, the level state of the overcurrent protection signal and the discharge control signal is stopped from being adjusted. The latch protection module comprises a transistor Q2 and a transistor Q3, when the trigger signal is at a high level, the transistor Q2 receives the trigger signal to be turned on, and provides a current to drive the transistor Q3 to be turned on; 3. The circuit of claim 1, wherein, after the transistor Q3 is turned on, a base current of the transistor Q2 is provided through a collector of the transistor Q3. The latch protection module further comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a diode D2, a diode D3 and a power supply V2, a first end of the resistor R1, a first end of the resistor R2 and a positive pole of the power supply V2 are connected, a second end of the resistor R1 and an emitter of the transistor Q3 are connected, a base of the transistor Q3 and a first end of the resistor R3 are connected, a collector of the transistor Q3, a first end of the resistor R4, a first end of the resistor R6, a first end of the resistor R5, a base of the transistor Q2 and an output end of the comparison judging module are connected; 4. The circuit of claim 3, wherein, a second end of the resistor R2, a collector of the transistor Q2, a second end of the resistor R3, a cathode of the diode D2 and a cathode of the diode D3 are connected, an anode of the diode D2 is connected with the overcurrent protection signal, and an anode of the diode D3 is connected with the discharge control signal; a negative pole of the power supply V2, an emitter of the transistor Q2, a second end of the resistor R6 and a second end of the resistor R5 are grounded. The latch release module comprises a transistor Q1, a resistor R8 and a resistor R9, a first end of the resistor R8, a base of the transistor Q1 and a first end of the resistor R9 are connected, a collector of the transistor Q1 is connected with an input end of the latch protection module, an emitter of the transistor Q1, a second end of the resistor R8 and a second end of the resistor R9 are grounded.

5. The circuit of claim 3, wherein, when the external control signal is at a high level: ​ 6. The circuit of claim 5, wherein, ​ The transistor Q1 is turned on and the base potential of the transistor Q2 is reduced; The transistor Q1 is turned off, cutting off the base current of the transistor Q3, so that the transistor Q3 is turned off.

7. The circuit of claim 1, wherein, The comparison judging module comprises a reference unit and a comparison unit, and the comparison unit is connected with the reference unit and a current sampling signal respectively; The reference unit is used for generating the preset reference voltage; The comparison unit is used for outputting the trigger signal when the current sampling signal exceeds the preset reference voltage.

8. The circuit of claim 7, wherein, The reference unit comprises a power supply V3, a resistor R10 and a resistor R11, The positive pole of the power supply V3 is connected with the first end of the resistor R10, the second end of the resistor R10 is connected with the input end of the comparison unit and the first end of the resistor R11, and the second end of the resistor R11 and the negative pole of the power supply V3 are grounded.

9. The circuit of claim 7, wherein, The comparison unit comprises a comparator U1A, a resistor R7, a power supply V1 and a diode D1, The non-inverting input end of the comparator U1A is connected with the positive pole of the battery, the inverting input end of the comparator U1A is connected with the output end of the reference unit, the first power input end of the comparator U1A is connected with the positive pole of the power supply V1 and the second end of the resistor R7, the output end of the comparator U1A is connected with the first end of the resistor R7 and the anode of the diode D1, the cathode of the diode D1 is connected with the input end of the latch protection module, and the second power input end of the comparator U1A, the negative pole of the power supply V1 and the negative pole of the battery are grounded.

10. An energy storage power supply, characterized by, The battery protection circuit comprises: The battery protection circuit according to any one of claims 1-9.

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