Battery micro short circuit detection circuit and electronic equipment

Abstract

The utility model discloses a battery micro short circuit detection circuit and electronic equipment, and relates to the technical field of micro short circuit detection. The battery micro short circuit detection circuit comprises a switch module, a voltage sampling module, a difference calculation module and a control module. The switch module is connected between the battery and the load, and is configured to disconnect the connection between the battery and the load in response to the first control signal. The voltage sampling module is connected with the battery and is configured to sample the voltage of the battery and output a digital signal corresponding to the voltage of the battery. The difference value calculation module is connected with the voltage sampling module and is configured to calculate the difference value between the digital signals corresponding to the two voltages which are spaced front and back. The control module is connected with the difference value calculation module and the switch module, outputs a first control signal, receives the difference value, and determines whether the micro short circuit occurs in the battery based on the relation between the difference value and reference data. Through the mode, whether the micro short circuit occurs in the battery or not can be accurately detected.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of micro-short circuit detection, and in particular to a battery micro-short circuit detection circuit and electronic equipment. Background Art

[0002] Secondary batteries, i.e. rechargeable batteries or storage batteries, may experience micro short circuits during manufacturing or use. Among them, lithium batteries, as commonly used secondary batteries, may have lithium dendrites and puncture the diaphragm during use due to low-temperature charging or excessive charging rate. This is a major cause of micro short circuits in batteries.

[0003] Battery micro-short circuit is one of the main causes of battery thermal runaway. Early detection of battery micro-short circuit anomalies and taking protective actions are important directions for improving battery safety. Therefore, it is particularly important to accurately detect whether a battery has a micro-short circuit. Utility Model Content

[0004] The embodiments of the present application provide a battery micro-short circuit detection circuit and an electronic device, which can relatively accurately detect whether a battery has a micro-short circuit.

[0005] In a first aspect, an embodiment of the present application provides a battery micro-short circuit detection circuit, comprising:

[0006] a switch module, connected between the battery and the load, and configured to disconnect the battery from the load in response to a first control signal;

[0007] a voltage sampling module, connected to the battery, configured to sample the voltage of the battery and output a digital signal corresponding to the voltage of the battery;

[0008] A difference calculation module is connected to the voltage sampling module and is configured to receive digital signals corresponding to two voltages spaced apart from each other and calculate the difference between the digital signals corresponding to the two voltages spaced apart from each other;

[0009] The control module is connected to the difference calculation module and the switch module respectively, and is configured to output the first control signal and receive the difference, and determine whether a micro short circuit occurs in the battery based on the relationship between the difference and a reference data.

[0010] In one or more embodiments, further comprising:

[0011] a driving module, connected between the control module and the switch module, and configured to output a second control signal to the switch module in response to the first control signal, wherein the level of the second control signal is the same as that of the first control signal, and the driving capability of the second control signal is greater than that of the first control signal;

[0012] The switch module is further configured to disconnect the battery and the load in response to the second control signal.

[0013] In one or more embodiments, the switch module includes a controllable switch;

[0014] The controllable switch is connected between the battery and the load.

[0015] In one or more embodiments, the controllable switch is one of a MOS tube, a triode and a relay.

[0016] In one or more embodiments, the voltage sampling module includes an analog-to-digital converter;

[0017] The analog-to-digital converter inputs the voltage of the battery and a preset reference voltage, compares the voltage of the battery with the preset reference voltage, and outputs a digital signal corresponding to the voltage of the battery based on the result of the comparison between the voltage of the battery and the preset reference voltage.

[0018] In one or more embodiments, the driving module includes a first switch tube and a second switch tube;

[0019] The first end of the first switch tube is short-circuited with the first end of the second switch tube, and the first control signal is input; the third end of the first switch tube is connected to the first power supply; the second end of the first switch tube is short-circuited with the second end of the second switch tube, and the second control signal is output; the third end of the second switch tube is grounded.

[0020] In a second aspect, an embodiment of the present application provides an electronic device, including a battery, a load, and the battery micro-short circuit detection circuit as described above, wherein the battery micro-short circuit detection circuit is connected between the battery and the load.

[0021] The beneficial effects of the present application are as follows: the battery micro-short circuit detection circuit of the embodiment of the present application includes a switch module, a voltage sampling module, a difference calculation module and a control module. The switch module is connected between the battery and the load, and is configured to disconnect the battery from the load in response to a first control signal. The voltage sampling module is connected to the battery, configured to sample the voltage of the battery, and output a digital signal corresponding to the voltage of the battery. The difference calculation module is connected to the voltage sampling module, configured to receive digital signals corresponding to two voltages of the front and back intervals, and calculate the difference between the digital signals corresponding to the two voltages of the front and back intervals. The control module is respectively connected to the difference calculation module and the switch module, and the control module is configured to output a first control signal and receive a difference, and based on the relationship between the difference and a reference data, determine whether a micro-short circuit occurs in the battery. In the above process, the first control signal can be outputted by the control module first to drive the switch module to disconnect. Since the connection between the battery and the load is disconnected first, the power consumption that may be generated by the load can be avoided as the power consumption of the battery self-discharge, that is, the error caused by the power consumption that may be generated by the load can be reduced, thereby improving the accuracy of detecting battery micro-short circuits, that is, it is possible to more accurately detect whether a battery micro-short circuit occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplary descriptions are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0023] Figure 1 This is a schematic diagram of the structure of the battery micro-short circuit detection circuit provided in the embodiment of the present application Figure 1 ;

[0024] Figure 2 This is a schematic diagram of the structure of the battery micro-short circuit detection circuit provided in the embodiment of the present application Figure 2 ;

[0025] Figure 3 is with Figure 2 Schematic diagram of circuit structure corresponding to the structure shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0027] It should be noted that, when an element is described as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0028] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0029] Please refer to Figure 1 , Figure 1 Schematic diagram of the structure of the battery detection device 100 provided in the embodiment of the present application. Figure 1 As shown, the battery detection device 100 includes a switch module 10, a voltage sampling module 20, a control module 30 and a difference calculation module 40. Among them, the switch module 10 is connected between the battery 200 and the load 300, the voltage sampling module 20 is connected to the battery 200, the difference calculation module 40 is connected to the voltage sampling module 20, and the control module 30 is connected to the difference calculation module 40 and the switch module 10 respectively.

[0030] Specifically, the switch module 10 is used to disconnect the battery 200 from the load 300 in response to the first control signal. It is understandable that if the control module 30 controls the switch module 10 to establish the connection between the battery 200 and the load 300 during the process of obtaining the battery voltage, the detection of the battery 200 is stopped. In addition, the above process of detecting the battery 200 can only be re-executed when the control module 30 controls the switch module 10 to disconnect the battery 200 from the load 300 again.

[0031] The voltage sampling module 20 is used to sample the voltage of the battery 200 and output a digital signal corresponding to the voltage of the battery 200. The analog signal (the voltage of the battery 200) is converted into a digital signal so that the subsequent circuit can perform signal processing.

[0032] The difference calculation module 40 is configured to receive digital signals corresponding to two voltages of the front and back intervals, and calculate the difference between the digital signals corresponding to the two voltages of the front and back intervals. Specifically, after receiving the digital signal corresponding to the first voltage, the difference calculation module 40 stores the digital signal, and waits until the preset time length, and receives the digital signal corresponding to the second voltage at the end of the preset time length. The digital signal corresponding to the first voltage and the digital signal corresponding to the second voltage are the digital signals corresponding to the two voltages of the front and back intervals. Afterwards, the difference calculation module 40 calculates the difference between the digital signal corresponding to the first voltage and the digital signal corresponding to the second voltage.

[0033] It is understandable that when a micro-short circuit occurs in the battery 200, a major electrical manifestation is an increase in the discharge rate of the battery 200 during self-discharge. For example, in one embodiment, the discharge rate of a battery during self-discharge is 2mV / day when it leaves the factory (the battery is a new battery at this time, and it can be considered that the battery has not experienced a micro-short circuit). Afterwards, if a micro-short circuit occurs in the battery, the discharge rate of the battery during self-discharge should be greater than 2mV / day. It can be seen that in this embodiment, by calculating the discharge rate of the battery, it is helpful to determine whether a micro-short circuit occurs in the battery. Therefore, when the control module 30 receives the above-mentioned difference, it can determine the actual discharge rate of the self-discharge of the battery 200 based on the difference and the preset duration, and by comparing the actual discharge rate with the benchmark data, it can accurately determine whether a micro-short circuit occurs in the battery 200.

[0034] Furthermore, in this embodiment, since the connection between the battery 200 and the load 300 is disconnected first, it is possible to avoid the power consumption that may be generated by the load 300 from being used as the power consumption of the self-discharge of the battery 200. Therefore, the error caused by the power consumption that may be generated by the load 300 can be reduced, which is conducive to improving the accuracy of detecting a micro-short circuit of the battery 200, that is, it is possible to more accurately detect whether a micro-short circuit occurs in the battery 200.

[0035] In one embodiment, the reference data is a reference discharge rate, which is a preset factory no-load discharge rate of the battery when it leaves the factory without load.

[0036] Among them, battery factory delivery refers to the process in which the battery manufacturer delivers the battery to the seller or other user after completing battery production, quality inspection and other work. In this process, key indicators such as battery quality, performance, and life should comply with relevant national standards and industry standards. It can be determined that the batteries leaving the factory are all batteries without micro-short circuits. This type of battery can be used to determine the benchmark discharge rate. In addition, in order to ensure the accuracy of the test, the battery used to determine the benchmark discharge rate should be the same type of battery as the battery that actually needs to be tested.

[0037] Specifically, under the premise that the battery is not connected to any circuit, that is, the battery is under no-load condition, two battery data of the battery are obtained at the interval before and after, and the discharge rate of the battery is calculated. The discharge rate is the factory no-load discharge rate, which is also the reference discharge rate.

[0038] In another embodiment, the reference discharge rate is a preset factory normally open discharge rate of the battery with normally open power consumption after the switch module 10 disconnects the connection between the battery and the load 300 when the battery leaves the factory.

[0039] The normally-on power consumption refers to the power consumed by the circuit structure or circuit module that remains connected to the battery after the battery is disconnected from the load 300. Figure 1Take the circuit structure shown as an example. After the connection between the battery and the load 300 is disconnected by the switch module 10, the positive electrode of the battery 200 is still connected to the switch module 10 and the voltage sampling module 20. At this time, the switch module 10 and the voltage sampling module 20 may consume the power of the battery, and this part of the power consumed is the normally open power consumption.

[0040] by Figure 1 Taking the circuit structure shown in FIG. 1 as an example, the process of obtaining the factory normally open discharge rate is as follows: First, the connection between the battery and the load 300 is disconnected by the switch module 10. Then, Figure 1 The battery in the test is replaced with a freshly-made battery (the battery is confirmed to have no micro-short circuit). Then, the battery data of the two batteries in the previous and next intervals are obtained. And the discharge rate of the battery is calculated. This discharge rate is the factory normally open discharge rate, which is also the reference discharge rate.

[0041] In this embodiment, by taking the discharge rate of the battery under normally-on power consumption as the reference discharge rate, the error caused by the normally-on power consumption can be compensated during the actual battery detection process, that is, the error caused by the normally-on power consumption can be eliminated, which is beneficial to further improve the accuracy of detecting whether the battery is micro-short-circuited.

[0042] In one embodiment, the control module 30 is further configured to calculate the difference between the discharge rate of the battery and the reference discharge rate, and if the difference is greater than a first difference threshold, it is determined that a micro short circuit occurs in the battery.

[0043] The first difference threshold value can be set according to the actual application situation, and the embodiment of the present application does not impose specific restrictions on this. In some embodiments, different first difference threshold values ​​can also be set accordingly based on the actual situation of the battery, for example, the first difference threshold value can be set based on the temperature of the battery and the number of charge and discharge times that the battery has experienced. For example, as the number of charge and discharge times that the battery has experienced increases, the first difference threshold value is set to be larger.

[0044] From the above embodiment, it can be seen that the reference discharge rate is the discharge rate obtained based on a battery without micro short circuit. By calculating the difference between the discharge rate of the battery and the reference discharge rate, the difference in discharge rate between the actually detected battery and the battery without micro short circuit can be determined.

[0045] If the difference between the discharge rate of the battery and the reference discharge rate is less than or equal to the first difference threshold, it can be considered that the difference in discharge rate between the actually detected battery and the battery without micro-short circuit is small, and the battery does not have micro-short circuit.

[0046] On the contrary, if the difference between the discharge rate of the battery and the reference discharge rate is greater than the first difference threshold, it can be considered that the discharge rate difference between the actual detected battery and the battery without micro-short circuit is large, the self-discharge rate of the battery is too large, and the battery has a micro-short circuit abnormality. Then, at this time, an early warning can be issued to prompt the user, and corresponding protective measures can be taken to reduce the risk of thermal runaway of the battery and improve the safety of battery use.

[0047] In one embodiment, the control module 30 is specifically configured to receive a battery micro-short circuit detection signal, and output a first control signal based on the battery micro-short circuit detection signal.

[0048] Among them, the battery micro-short circuit detection signal can be generated by the control module 30, or sent to the control module 30 by other modules. For example, in one embodiment, a communication connection can be established between the control module 30 and an electronic device such as a mobile phone, and the battery micro-short circuit detection signal can be transmitted to the control module 30 by operating the mobile phone. For example, in other embodiments, the control module 30 can also automatically generate a battery micro-short circuit detection signal after a preset condition is met.

[0049] In another embodiment, the control module 30 is further configured to obtain a change in the battery data within a second time period if the battery 200 is determined to be fully charged based on the battery data. If the change in the battery data is less than a preset change, it is determined that a battery micro short circuit detection signal is received.

[0050] The preset change amount is a preset change amount of the battery data, which can be set according to the actual application situation, and the embodiment of the present application does not make specific restrictions on this. The second duration is a preset duration, which can be set according to the actual application situation, and the embodiment of the present application does not make specific restrictions on this.

[0051] In this embodiment, if the change in battery data within the second time period is less than the preset change, it can be determined that the battery 200 has not been used for a period of time after being fully charged. At this time, the control module 30 defaults to receiving a battery micro-short circuit detection signal, and can perform a micro-short circuit test on the battery 200 and output a first control signal.

[0052] Taking the battery detection device 100 as an example, when the user plugs the mobile phone into a charging cable for charging before taking a rest, after the battery of the mobile phone is fully charged, the change amount of the battery data in the second time period is less than the preset change amount because the user is resting and not operating the mobile phone. At this time, the control module 30 determines that the battery micro-short circuit detection signal is received and starts to execute the process of performing micro-short circuit detection on the battery.

[0053] In one embodiment of the present application, Figure 2 As shown, the battery micro-short circuit detection circuit 100 also includes a driving module 50 .

[0054] The driving module 50 is connected between the control module 30 and the switch module 10. The driving module 50 is configured to output a second control signal in response to the first control signal. The level of the second control signal is the same as that of the first control signal, and the driving capability of the second control signal is greater than that of the first control signal. The switch module 10 is also configured to disconnect the battery 200 from the load 300 in response to the second control signal.

[0055] In this embodiment, the second control signal with stronger driving capability is output based on the first control signal to drive the switch module 10 to be stably turned on and off, which is beneficial to improving the working stability of the battery micro-short circuit detection circuit 100.

[0056] It should be noted that if Figure 2 The hardware structure of the battery micro-short circuit detection circuit 100 shown is only an example, and the battery micro-short circuit detection circuit 100 may have more or fewer components than those shown in the figure, may combine two or more components, or may have different component configurations, and the various components shown in the figure may be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application-specific integrated circuits. For example, in Figure 1 and Figure 2 In the illustrated embodiment, the switch module 10 is disposed between the positive electrode of the battery 200 and the positive electrode of the load 300 as an example. In other embodiments, the switch module 10 may also be disposed between the negative electrode of the battery 200 and the negative electrode of the load 300 .

[0057] Please refer to Figure 3 , Figure 3 Shown with Figure 2 A circuit structure corresponding to the structure shown in FIG. Figure 3 As shown, the switch module 10 includes a controllable switch K1 .

[0058] The controllable switch K1 is connected between the battery and the load. The controllable switch K1 is controlled by the control module 30, and the controllable switch K1 is disconnected upon receiving a first control signal to disconnect the battery 200 from the load 300.

[0059] In one embodiment of the present application, the controllable switch K1 is one of a MOS tube, a triode and a relay. Taking the controllable switch K1 as a MOS tube as an example, the gate of the MOS tube is connected to the driving module 20 to input the second control signal, the source of the MOS tube is connected to the positive electrode of the battery 200, and the drain of the MOS tube is connected to the load 300.

[0060] In other embodiments, the controllable switch K1 may also be an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, etc.

[0061] In an embodiment of the present application, the voltage sampling module 20 includes an analog-to-digital converter 21 .

[0062] The analog-to-digital converter 21 inputs the voltage of the battery 200 and the preset reference voltage VREF, compares the voltage of the battery 200 with the preset reference voltage VREF, and outputs a digital signal corresponding to the voltage of the battery 200 based on the result of the comparison between the voltage of the battery 200 and the preset reference voltage VREF. The preset reference voltage VREF can be set based on the actual application scenario, and the embodiment of the present application does not impose any specific limitation on this.

[0063] In an embodiment of the present application, the driving module 20 includes a first switch tube Q1 and a second switch tube Q2 .

[0064] Among them, the first end of the first switch tube Q1 is short-circuited with the first end of the second switch tube Q2, and the first control signal is input, the third end of the first switch tube Q1 is connected to the first power supply V1, the second end of the first switch tube Q1 is short-circuited with the second end of the second switch tube Q2, and the second control signal is output, and the third end of the second switch tube Q2 is grounded GND.

[0065] Specifically, the first control signal and the second control signal are both level signals. In this embodiment, the first switch tube Q1 and the second switch tube Q2 are both triodes. Among them, the first end of the first switch tube Q1 (the second switch tube Q2) is the base of the triode, the second end of the first switch tube Q1 (the second switch tube Q2) is the emitter of the triode, and the third end of the first switch tube Q1 (the second switch tube Q2) is the collector of the triode.

[0066] In practical applications, the first switch tube Q1 and the second switch tube Q2 are configured as the same switch tube. The first switch tube Q1 and the second switch tube Q2 are always in a state where one is turned on and the other is turned off. That is, only one of the two symmetrical power switch tubes is turned on at a time, so the conduction loss is small and the efficiency is high, thereby improving the driving capability.

[0067] The embodiment of the present application further provides an electronic device, which includes a battery, a load, and a battery micro-short circuit detection circuit 100 in any embodiment of the present application. The battery micro-short circuit detection circuit 100 is connected between the battery and the load.

[0068] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0069] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Under the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. It should be understood by ordinary technicians in this field that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery micro-short circuit detection circuit, characterized in that: include: a switch module, connected between the battery and the load, and configured to disconnect the battery from the load in response to a first control signal; a voltage sampling module, connected to the battery, configured to sample the voltage of the battery and output a digital signal corresponding to the voltage of the battery; A difference calculation module is connected to the voltage sampling module and is configured to receive digital signals corresponding to two voltages spaced apart from each other and calculate the difference between the digital signals corresponding to the two voltages spaced apart from each other; The control module is connected to the difference calculation module and the switch module respectively, and is configured to output the first control signal and receive the difference, and determine whether a micro short circuit occurs in the battery based on the relationship between the difference and a reference data.

2. The battery micro-short circuit detection circuit according to claim 1, characterized in that: Also includes: a driving module connected between the control module and the switch module, and configured to output a second control signal to the switch module in response to the first control signal, wherein the level of the second control signal is the same as that of the first control signal, and the driving capability of the second control signal is greater than that of the first control signal; The switch module is further configured to disconnect the battery and the load in response to the second control signal.

3. The battery micro-short circuit detection circuit according to claim 1 or 2, characterized in that: The switch module includes a controllable switch; The controllable switch is connected between the battery and the load.

4. The battery micro-short circuit detection circuit according to claim 3, characterized in that: The controllable switch is one of a MOS tube, a triode and a relay.

5. The battery micro-short circuit detection circuit according to claim 1 or 2, characterized in that: The voltage sampling module includes an analog-to-digital converter; The analog-to-digital converter inputs the voltage of the battery and a preset reference voltage, compares the voltage of the battery with the preset reference voltage, and outputs a digital signal corresponding to the voltage of the battery based on the result of the comparison between the voltage of the battery and the preset reference voltage.

6. The battery micro-short circuit detection circuit according to claim 2, characterized in that: The driving module includes a first switch tube and a second switch tube; The first end of the first switch tube is short-circuited with the first end of the second switch tube, and the first control signal is input; the third end of the first switch tube is connected to the first power supply; the second end of the first switch tube is short-circuited with the second end of the second switch tube, and the second control signal is output; the third end of the second switch tube is grounded.

7. An electronic device, characterized in that: It comprises a battery, a load and a battery micro-short circuit detection circuit as described in any one of claims 1 to 6, wherein the battery micro-short circuit detection circuit is connected between the battery and the load.

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