Battery pack and anti-breakdown circuit thereof

Abstract

The utility model discloses a battery pack and an anti-breakdown circuit thereof, and the battery pack comprises a charging and discharging circuit which is used for charging or discharging; the battery cell unit is used for storing electric energy; the switch end of the semiconductor switch is electrically connected with the charging and discharging circuit and the battery cell unit respectively; the single chip microcomputer is used for sending a control signal to the control end of the semiconductor switch; the two ends of the first resistor are electrically connected to the single chip microcomputer and the control end of the semiconductor switch respectively; the two ends of the second resistor are electrically connected to the control end of the semiconductor switch and the negative electrode of the switch end respectively; the positive electrode and the negative electrode of the voltage-regulator tube are electrically connected to the negative electrode of the control end and the switch end of the semiconductor switch respectively; wherein the value range of the ratio of the resistance value of the second resistor to the resistance value of the first resistor is 90-150. The battery pack and the anti-breakdown circuit thereof have the beneficial effects that the semiconductor switch can be effectively prevented from being broken down by relatively high voltage.

Description

Technical Field

[0001] This application relates to the technical field of battery pack control, and more specifically, to a battery pack and its anti-breakdown circuit. Background Art

[0002] There are often multiple groups of battery cell units in a battery pack, and a battery cell unit can be composed of one or more battery cells. During the daily use of the battery pack, the BMS device of the battery pack controls charging and discharging through separate semiconductor switches.

[0003] Since the voltage of the battery pack is getting higher and higher, more and more semiconductor switches are used. And due to the increasingly harsh usage scenarios, semiconductor switches are prone to failure due to breakdown and other reasons. Existing battery packs do not provide anti-breakdown protection for semiconductor switches. Summary of the Invention

[0004] This section of the application is used to briefly introduce concepts, which will be described in detail in the following detailed implementation section. This section of the application is not intended to identify the key features or essential features of the claimed technical solution, nor is it intended to limit the scope of the claimed technical solution.

[0005] Some embodiments of this application propose a battery pack and its anti-breakdown circuit to solve the technical problems mentioned in the above background art section.

[0006] As a first aspect of this application, some embodiments of this application provide an anti-breakdown circuit for preventing a semiconductor switch from being broken down. The anti-breakdown circuit includes: a first resistor, one end of which is electrically connected to the control end of the semiconductor switch; a second resistor, both ends of which are respectively electrically connected to the control end and the negative pole of the switch end of the semiconductor switch; a zener diode, the positive and negative poles of which are respectively electrically connected to the control end and the negative pole of the switch end of the semiconductor switch; wherein, the value range of the ratio of the resistance value of the second resistor to the resistance value of the first resistor is 90 to 150; the value range of the breakdown voltage of the zener diode is 12V to 24V.

[0007] Further, the anti-breakdown circuit further includes: a diode, the negative pole of which is electrically connected to the other end of the first resistor.

[0008] Further, the value range of the resistance value of the first resistor is 6 kΩ to 12 kΩ.

[0009] Further, the value range of the resistance value of the second resistor is 0.8 MΩ to 1.2 MΩ.

[0010] Further, the breakdown voltage of the zener diode is 18V.

[0011] As a second aspect of the present application, some embodiments of the present application provide a battery pack, including: a charging and discharging circuit for charging or discharging; a battery cell unit for storing electric energy; a semiconductor switch, whose switching terminals are respectively electrically connected to the charging and discharging circuit and the battery cell unit; a single-chip microcomputer for sending a control signal to the control terminal of the semiconductor switch; a first resistor, whose two ends are respectively electrically connected to the single-chip microcomputer and the control terminal of the semiconductor switch; a second resistor, whose two ends are respectively electrically connected to the control terminal of the semiconductor switch and the negative electrode of the switching terminal; a voltage stabilizing diode, whose positive and negative electrodes are respectively electrically connected to the control terminal of the semiconductor switch and the negative electrode of the switching terminal; wherein, the value range of the ratio of the resistance value of the second resistor to that of the first resistor is 90 to 150; the value range of the stabilizing voltage of the voltage stabilizing diode is 12V to 24V.

[0012] Further, the battery pack further includes: a diode, whose positive and negative electrodes are respectively electrically connected to the single-chip microcomputer and the first resistor.

[0013] Further, the value range of the resistance value of the first resistor is 6 kΩ to 12 kΩ.

[0014] Further, the value range of the resistance value of the second resistor is 0.8 MΩ to 1.2 MΩ.

[0015] Further, the stabilizing voltage of the voltage stabilizing diode is 18V.

[0016] Further, the semiconductor switch is a MOS transistor switch; the resistance value of the first resistor is 10 kΩ; the resistance value of the second resistor is 1 MΩ.

[0017] The beneficial effect of the present application is that: a battery pack capable of effectively preventing the semiconductor switch from being broken down by a relatively high voltage and its anti-breakdown circuit are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings that form a part of the present application are used to provide a further understanding of the present application, making other features, objectives, and advantages of the present application more obvious. The schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation to the present application.

[0019] In addition, throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic, and the elements and elements are not necessarily drawn to scale.

[0020] In the accompanying drawings:

[0021] Figure 1 is a schematic diagram of a partial circuit in a battery pack according to an embodiment of the present application;

[0022] Figure 2 is a schematic diagram of a partial circuit in a battery pack according to another embodiment of the present application. Detailed implementation manners

[0023] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not used to limit the protection scope of the present disclosure.

[0024] In addition, it should be noted that for the sake of convenience of description, only parts related to the relevant invention are shown in the drawings. Without conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other.

[0025] It should be noted that concepts such as "first" and "second" mentioned in the present disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence relationship of the functions performed by these devices, modules or units.

[0026] It should be noted that the modifications of "one" and "multiple" mentioned in the present disclosure are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0027] The names of the messages or information exchanged between multiple devices in the embodiments of the present disclosure are only for illustrative purposes and are not used to limit the scope of these messages or information.

[0028] The present disclosure will be described in detail below with reference to the drawings and in combination with embodiments.

[0029] Referring to Figure 1 As shown, the battery pack of the present application includes: a charge and discharge circuit, a battery cell unit, a semiconductor switch, and a main control single-chip microcomputer.

[0030] Among them, the charge and discharge circuit is used for charging or discharging; the battery cell unit is used for storing electric energy; the switch terminals of the semiconductor switch are respectively electrically connected to the charge and discharge circuit and the battery cell unit; the single-chip microcomputer is used for sending a control signal to the control terminal of the semiconductor switch.

[0031] More specifically, the main control single-chip microcomputer sends a control signal to the control terminal of the semiconductor switch to make the semiconductor switch conduct or disconnect.

[0032] When a high voltage is instantaneously applied to the semiconductor switch, it is easy to cause the control terminal and the switch terminal as the negative electrode to be broken down, resulting in the problem of the failure of the semiconductor switch. For example, when the semiconductor switch is a MOS transistor switch, an excessive control voltage is likely to cause the gate and the source to be broken down.

[0033] As shown Figure 1 in the figure, a second resistor R2 is connected in parallel between the control terminal of the semiconductor switch Q1 and the switch terminal serving as the negative electrode. The second resistor R2 has a relatively high resistance value and can effectively divide the voltage. As a further solution, a voltage stabilizing diode ZG is also connected in parallel between the control terminal of the semiconductor switch Q1 and the switch terminal serving as the negative electrode. The positive electrode of the voltage stabilizing diode ZG is electrically connected to the control terminal of the semiconductor switch Q1, and the negative electrode of the voltage stabilizing diode ZG is electrically connected to the switch terminal serving as the negative electrode of the semiconductor switch Q1.

[0034] Furthermore, as shown Figure 1 in the figure, when the semiconductor switch Q1 is a MOS transistor switch, both ends of the second resistor R2 are respectively connected to the gate G and the source S of the MOS transistor switch; the positive electrode of the voltage stabilizing diode ZG is electrically connected to the gate G of the MOS transistor switch; the negative electrode of the voltage stabilizing diode ZG is electrically connected to the source S of the MOS transistor switch.

[0035] In order to make the voltage signal transmitted by the main control single-chip microcomputer to the control terminal of the semiconductor switch Q1 relatively stable, a diode Z1 and a first resistor R1 are sequentially connected between the main control single-chip microcomputer and the control terminal of the semiconductor switch Q1. As a preferred solution, when the semiconductor switch Q1 is a MOS transistor switch, a diode Z1 and a first resistor R1 are sequentially connected between the main control single-chip microcomputer and the gate G of the MOS transistor switch; the gate-drain D of the MOS transistor switch is electrically connected to the charge and discharge circuit.

[0036] In this way, even when the voltage signal of the main control single-chip microcomputer has an instantaneous high voltage, through the sharing of the high voltage by the first resistor R1, the second resistor R2 and the voltage stabilizing diode ZG, the direct impact of the instantaneous high voltage on the semiconductor switch Q1 is reduced.

[0037] As a specific solution, the value range of the ratio of the resistance value of the second resistor R2 to the resistance value of the first resistor R1 is 90 to 150; more specifically, it is 95 to 105, and the preferred value is 100.

[0038] As a specific solution, the value range of the resistance value of the first resistor R1 is 6 kΩ to 12 kΩ; preferably, the resistance value of the first resistor R1 is 10 kΩ.

[0039] As a specific solution, the value range of the resistance value of the second resistor R2 is 0.8 MΩ to 1.2 MΩ; preferably, the resistance value of the second resistor R2 is 1 MΩ.

[0040] As a specific solution, the value range of the stable voltage of the voltage stabilizing diode ZG is 12V to 24V, preferably 18V.

[0041] As shown Figure 2As shown, in order to enable the battery pack to detect a failed semiconductor switch when the semiconductor switch is damaged by impact, thereby reducing the safety risk during charging and discharging of the battery pack.

[0042] Specifically, the battery pack has multiple correspondingly arranged battery cell units (not shown in the figure) and semiconductor switches Q1, Q2, Q3, and Q4. Therefore, the battery pack needs to determine the effectiveness of all semiconductor switches Q1, Q2, Q3, and Q4 to ensure normal charging and discharging of the battery pack. Each semiconductor switch Q1, Q2, Q3, and Q4 is electrically connected to a voltage-dividing resistor R2 and a sampling resistor R3 through shunt resistors R11, R12, R13, and R14 respectively. The other end of the voltage-dividing resistor R2 is grounded. The sampling resistor R3 is electrically connected to a detection single-chip microcomputer through a diode Z2; at the same time, the sampling resistor R3 is electrically connected to the positive electrode of a capacitor C1, and the negative electrode of the capacitor C1 is grounded.

[0043] When the semiconductor switches Q1, Q2, Q3, and Q4 are normal, the voltage at the control terminals of the semiconductor switches Q1, Q2, Q3, and Q4 is approximately 12V; when the semiconductor switches Q1, Q2, Q3, and Q4 fail, the voltage at the control terminals of the semiconductor switches Q1, Q2, Q3, and Q4 will be pulled down to less than 8V. The detection single-chip microcomputer can know whether the semiconductor switches Q1, Q2, Q3, and Q4 have failed according to the collected voltage signal. If there is no failure, the normal charging and discharging operation will continue; if there is a failure, the system will alarm and stop the normal charging control.

[0044] As a specific solution, the resistance value of the shunt resistor R1 is greater than the resistance value of the voltage-dividing resistor R2, and the value range of the ratio of their resistance values is 4 to 6. More specifically, the resistance value of the shunt resistor R1 ranges from 4 MΩ to 6 MΩ.

[0045] As a specific solution, the resistance value of the sampling resistor R3 is much smaller than the resistance values of the shunt resistor R1 and the voltage-dividing resistor R2. Specifically, the value range of the ratio of the resistance value of the shunt resistor R1 to the resistance value of the sampling resistor R3 is 4000 to 6000. As a preferred solution, the resistance value of the sampling resistor R3 is 1000 ohms.

[0046] Generally speaking, only during charging and discharging will the battery pack send control signals to semiconductor switches Q1, Q2, Q3, and Q4 to turn them on. However, if semiconductor switches Q1, Q2, Q3, and Q4 are in a failed state during charging or discharging, it will pose a safety hazard to the entire battery pack. If the main control program of the battery pack is executed for a period of time before each charge and discharge, and then the main program of the battery pack is continued or terminated according to the result of the validity detection, this will undoubtedly cause power consumption waste of the battery pack, because neither the charging program nor the discharging program in the main control program of the battery pack is simply turned on or off, but the duty cycle of turning on semiconductor switches Q1, Q2, Q3, and Q4 needs to be set according to the voltage of the battery cell unit, etc. Therefore, this not only increases energy consumption but also cannot obtain a stable validity detection signal, resulting in false alarms or detection failures.

[0047] As a further solution, as Figure 2 shown, a trigger single-chip microcomputer is also set in the battery pack. The trigger single-chip microcomputer is electrically connected to the detection single-chip microcomputer so that they can interact to communicate signals. The trigger single-chip microcomputer is electrically connected to semiconductor switches Q1, Q2, Q3, and Q4 through diode Z3 respectively.

[0048] After the detection single-chip microcomputer detects the change in the voltage signal brought by connecting the charger or the electrical load to the charge and discharge circuit, it does not send a trigger signal to the main control single-chip microcomputer (not shown in the figure) responsible for the charge and discharge program in the battery pack first, but first detects the voltage signal collected by the above detection circuit and obtains the voltage value of the voltage signal. At this time, since there is no voltage at the control end of semiconductor switch Q1, the detection single-chip microcomputer determines that the current semiconductor switch Q1 is in an idle state.

[0049] Then, the detection single-chip microcomputer sends a trigger signal to the trigger single-chip microcomputer, and the trigger single-chip microcomputer sends a square wave signal for briefly turning on semiconductor switch Q1 to the control end of semiconductor switch Q1. At the same time, the detection single-chip microcomputer detects the voltage value of the voltage signal again. At this time, if semiconductor switch Q1 fails, the voltage value of the voltage signal detected by the detection single-chip microcomputer again will be different from the voltage value of the voltage signal collected under the normal state of semiconductor switch Q1. If the detection validity passes, then the detection single-chip microcomputer can send a program for triggering normal charge and discharge to the main control single-chip microcomputer in the BMS device, which can greatly solve the overall program judgment time and energy consumption. As a preferred solution, the trigger single-chip microcomputer itself can be the main control single-chip microcomputer responsible for the charge and discharge program in the battery pack. The difference is that an additional validity detection program needs to be set in the main control single-chip microcomputer outside the charge and discharge program.

[0050] As a preferred solution, the detection single-chip microcomputer and the trigger single-chip microcomputer can be compatible as one single-chip microcomputer, and this single-chip microcomputer can of course also be used as the main control single-chip microcomputer.

[0051] The shunt resistors R11, R12, R13, and R14 can have different resistance values. At this time, when the single-chip microcomputer is triggered to directly apply a voltage signal to the control terminal switch of the semiconductor, when different semiconductor switches fail, the voltage values that the detection single-chip microcomputer can detect are different. In this way, the detection single-chip microcomputer can help the system determine which specific semiconductor switch has failed according to the specific data of the voltage value.

[0052] The above description is only some preferred embodiments of the present disclosure and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above inventive concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) disclosed in the embodiments of the present disclosure that have similar functions.

Claims

1. An anti-breakdown circuit for preventing a semiconductor switch from being broken down; Features: The anti-breakdown circuit comprises: A first resistor, one end of which is electrically connected to the control end of the semiconductor switch; A second resistor, two ends of which are electrically connected to the control end of the semiconductor switch and the negative electrode of the switch end respectively; A voltage regulator tube, the positive electrode and the negative electrode of which are electrically connected to the control end and the negative electrode of the switch end of the semiconductor switch respectively; The ratio of the resistance value of the second resistor to the resistance value of the first resistor ranges from 90 to 150; and the stable voltage of the voltage regulator ranges from 12V to 24V.

2. The anti-breakdown circuit according to claim 1, characterized in that: The anti-breakdown circuit also includes: A diode, a cathode of which is electrically connected to the other end of the first resistor.

3. The anti-breakdown circuit according to claim 2, characterized in that: The resistance value of the first resistor ranges from 6 kilo-ohms to 12 kilo-ohms.

4. The anti-breakdown circuit according to claim 3, characterized in that: The resistance value of the second resistor ranges from 0.8 megohms to 1.2 megohms.

5. The anti-breakdown circuit according to claim 4, characterized in that: The stable voltage of the voltage regulator tube is 18V.

6. A battery pack comprising: A charge and discharge circuit, used for charging or discharging; Battery cell unit, used to store electrical energy; A semiconductor switch, the switch ends of which are electrically connected to the charging and discharging circuit and the battery cell unit respectively; A single chip microcomputer, used for sending a control signal to a control terminal of the semiconductor switch; Features: The battery pack further comprises: A first resistor, two ends of which are electrically connected to the single chip microcomputer and the control end of the semiconductor switch respectively; A second resistor, two ends of which are electrically connected to the control end and the negative electrode of the switch end of the semiconductor switch respectively; A voltage regulator tube, the positive electrode and the negative electrode of which are electrically connected to the control end and the negative electrode of the switch end of the semiconductor switch respectively; The ratio of the resistance value of the second resistor to the resistance value of the first resistor ranges from 90 to 150; and the stable voltage of the voltage regulator ranges from 12V to 24V.

7. The battery pack according to claim 6, characterized in that: The battery pack further comprises: A diode, whose anode and cathode are electrically connected to the single chip microcomputer and the first resistor respectively.

8. The battery pack according to claim 7, characterized in that: The resistance value of the first resistor ranges from 6 kilo-ohms to 12 kilo-ohms.

9. The battery pack according to claim 8, characterized in that: The resistance value of the second resistor ranges from 0.8 megohms to 1.2 megohms.

10. The battery pack according to claim 9, characterized in that: The stable voltage of the voltage regulator tube is 18V.

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