Battery abnormality diagnosis circuit

Abstract

The utility model relates to a battery abnormity diagnosis circuit in the technical field of batteries, which comprises a battery pack, a BMS (battery management system), a switch module, a current stabilization module, an excitation module and an output module, and the output module can be connected with a load or a charging power supply. The switch module is connected with the battery pack and the output module and used for conducting electric connection between the battery pack and the output module. The current stabilizing module is connected with the excitation module and the switch module and used for stabilizing current. Compared with the prior art, the battery pack, the switch module, the current stabilization module and the excitation module form the excitation loop, and the excitation loop is provided with the current stabilization module capable of stabilizing current, so that the excitation module can send a stable excitation signal to a battery after receiving a detection signal of a BMS (Battery Management System); therefore, a more accurate response signal of the battery pack is obtained, and more accurate impedance detection is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, especially relate to a battery abnormal diagnosis circuit. BACKGROUND

[0002] Lithium ion battery inevitably appears a series of problems in long -term use process, such as internal resistance growth and temperature abnormal rise etc.If the state change is not captured in time, will constitute major hidden danger to the safe operation of electric vehicle. Among them, impedance as the important parameter of monitoring battery internal state, not only can reflect the aging state of battery, and it is closely related to its internal temperature.

[0003] However, the full frequency measurement of battery impedance currently often depends on the bulky electrochemical workstation, which is not only time -consuming and difficult to practical application. In addition, there is certain difficulty to integrate impedance detection and power battery electrical system, and it can influence the accuracy of impedance detection.

[0004] Therefore, an urgent need for a battery abnormal diagnosis circuit can solve the above problems. UTILITY MODEL CONTENTS

[0005] Therefore, the utility model provides a battery abnormal diagnosis circuit to detect the state change of battery efficiently and accurately. The technical scheme of the utility model is as follows:

[0006] The utility model provides a battery abnormal diagnosis circuit, including battery group, BMS, switch module, steady flow module, excitation module, output module, the output module connects load or charging power supply, the first end of switch module connects the first end of battery group, the second end of switch module connects the first end of output module, for the electric connection between the conduction battery group and output module, the first end of steady flow module connects the second end of switch module, the second end of steady flow module connects the first end of excitation module, for stabilizing current, the second end of excitation module and the second end of battery group are connected, the third end of excitation module is connected with BMS, be configured as receiving the detection signal of BMS, and send excitation signal to battery group, BMS is configured as sending detection signal to excitation module.

[0007] In a possible implementation, the current stabilizing module comprises a current stabilizing unit, a current control resistor, a current stabilizing diode and an operational amplifier; a first input end of the current stabilizing unit is connected to a second end of the switch module, configured to receive a charging current when the output module is connected to a charging power supply; a second input end of the current stabilizing unit is connected to an output end of the operational amplifier, configured to receive an amplified signal of the operational amplifier, and generate a first current signal according to the amplified signal; a first end of the current control resistor is connected to an output end of the current stabilizing unit, and a second end of the current control resistor is electrically connected to a first end of the excitation module.

[0008] In a possible implementation, a first input end of the operational amplifier is connected to a first end of the current control resistor, a second input end of the operational amplifier is connected to a second end of the current control resistor, configured to receive the first current signal flowing through the current control resistor and generate the amplified signal; and an output end of the operational amplifier is connected to the second input end of the current stabilizing unit, configured to send the amplified signal to the current stabilizing unit.

[0009] In a possible implementation, a first end of the current stabilizing module is connected to a first end of the output module, configured to receive the charging current when the output module is connected to the charging power supply; and a third end of the current stabilizing module is connected to a first end of the battery pack, configured to pre-charge the battery pack when the output module is connected to the charging power supply.

[0010] In a possible implementation, a first end of the current stabilizing unit is connected to a first end of the output module, configured to receive the charging current when the output module is connected to the charging power supply; and the current stabilizing module further comprises a current stabilizing diode, a positive electrode of the current stabilizing diode is connected to a second end of the current control resistor, and a negative electrode of the current stabilizing diode is connected to a first end of the battery pack.

[0011] In a possible implementation, the excitation module comprises an excitation switch and an excitation resistor, a first end of the excitation resistor is connected to a second end of the current stabilizing module, and a second end of the excitation resistor is connected to a first end of the excitation switch; a second end of the excitation switch is connected to a second end of the battery, and a third end of the excitation switch is connected to the BMS, configured to receive the detection signal, and close or open according to the detection signal, to send an excitation signal to the battery pack.

[0012] In a possible implementation, the excitation switch is an N-type excitation MOS tube, a drain of the excitation MOS tube is connected to the second end of the excitation resistor, a source of the excitation MOS tube is connected to the negative electrode of the battery pack, and a gate of the excitation MOS tube is connected to the BMS, configured to receive a switching signal sent by the BMS, and close or open according to the switching signal.

[0013] In a possible implementation, the switch module further comprises a first N-type MOS tube, a second N-type MOS tube, a first diode and a second diode, the drain of the first MOS tube is connected to the positive pole of the battery pack, the source of the first MOS tube is connected to the source of the second MOS tube, and the drain of the second MOS tube is connected to the output module and the current stabilizing module.

[0014] In a possible implementation, the gates of the first MOS tube and the second MOS tube are connected to the BMS, for receiving a switch signal of the BMS, and being closed or opened according to the switch signal.

[0015] In a possible implementation, the positive pole of the first diode is connected to the source of the first MOS tube, and the negative pole of the first diode is connected to the drain of the first MOS tube; the positive pole of the second diode is connected to the source of the second MOS tube, and the negative pole of the second diode is connected to the drain of the second MOS tube.

[0016] In a possible implementation, the utility model further comprises a discharging module, the first end of the discharging module is connected to the first end of the battery pack, and the second end of the discharging module is connected to the output module, for conducting the connection between the battery pack and the output module when the output module is connected to a load.

[0017] The utility model has the advantages of the following:

[0018] 1. In the utility model, the battery pack, the switch module, the current stabilizing module, the excitation module and the BMS cooperate to form a stable excitation loop.

[0019] 2. The utility model adjusts the current and keeps it constant through the current stabilizing module, avoids the problem of excessive instantaneous current when the voltage of the battery pack is too low, and improves the reliability and safety of the system.

[0020] 3. The utility model realizes pre-charging and detection of the battery pack through the switch module and the current stabilizing module. When charging, the switch module is opened, and the battery pack is first pre-charged stably through the current stabilizing module; when detecting, the switch module is closed, and accurate detection is realized through the current stabilizing module and the excitation module, ensuring the diversity and flexibility of functions.

[0021] 4. The utility model realizes power supply to an external load through the discharging module, and this design ensures that the battery pack can stably operate in different working modes and improves the overall performance of the system. DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only an embodiment of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0023] Wherein the same parts are indicated by the same reference numerals. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "bottom" and "top", "inner" and "outer" refer to the directions towards or away from the geometric center of a particular component.

[0024] Figure 1 The overall structural diagram of the embodiment of the present application;

[0025] Figure 2 The specific work flow chart of the embodiment of the present application.

[0026] In the above drawings, the meanings of the reference numerals are as follows:

[0027] 1, battery pack;

[0028] 2, switch module;

[0029] 21, first MOS tube;

[0030] 22, second MOS tube;

[0031] 3, current stabilizing module;

[0032] 31, current stabilizing unit;

[0033] 32, current control resistor;

[0034] 33, current stabilizing diode;

[0035] 34, operational amplifier;

[0036] 4, excitation module;

[0037] 41, excitation MOS tube;

[0038] 42, excitation resistor;

[0039] 5, discharging module;

[0040] 6, output module. DETAILED DESCRIPTION

[0041] The technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application and the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0042] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specific embodiments are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0043] In the description of the specific embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0044] In the present application, "embodiments" means that the specific features, structures or properties described in combination with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments.

[0045] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents a "or" relationship between the front and rear associated objects.

[0046] Throughout this invention, numerical values ​​represent approximate measurements or limits of a range to cover minute deviations from a given value, as well as embodiments having approximately the mentioned value and embodiments having the exact mentioned value. Except for the working examples provided at the end of the detailed description, all numerical values ​​of parameters, quantities, or conditions in the appended claims should be understood to be modified in all cases by the term “about,” regardless of whether “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows for some minute inaccuracy that is somewhat close to the exact value of the value; approximately or reasonably close to the value; almost. If the inaccuracy provided by “about” is not otherwise understood in this common sense in the art, then “about” as used in this invention at least indicates a variation that can be produced by common methods of measuring and using such parameters. For example, “about” may include a variation of less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in some respects, optionally less than or equal to 0.1%.

[0047] Additionally, the disclosure of the range includes the disclosure of all values ​​across the entire range and the disclosure of further subdivided ranges, including the endpoints and subranges given for these ranges.

[0048] The embodiments of this utility model will be described in more detail below through examples. It should be noted that the embodiments of this utility model are not limited to these examples.

[0049] Example

[0050] In this embodiment, as Figure 1 and Figure 2 As shown, a battery fault diagnosis circuit includes a battery pack 1, a battery management system (BMS), a switching module 2, a current stabilizing module 3, an excitation module 4, and an output module 6. The first terminal of the switching module 2 is connected to the first terminal of the battery pack 1, and the second terminal of the switching module 2 is connected to the first terminal of the output module 6, for establishing an electrical connection between the battery pack 1 and the output module 6. The first terminal of the current stabilizing module 3 is connected to the second terminal of the switching module 2, and the second terminal of the current stabilizing module 3 is connected to the first terminal of the excitation module 4, for stabilizing the current. The second terminal of the excitation module 4 is connected to the second terminal of the battery pack 1, and the third terminal of the excitation module 4 is connected to the BMS, configured to receive detection signals from the BMS and send excitation signals to the battery pack 1. The BMS is connected to the excitation module 4 and configured to send detection signals to the excitation module 4. The output module 6 is configured to connect to a load or a charging power supply, and the detection signals are switching signals sent at a certain frequency.

[0051] Through the above arrangement, the battery pack 1, the switch module 2, the current stabilizing module 3 and the excitation module 4 can form an excitation loop, and the current stabilizing module 3 capable of stabilizing the current is arranged on the excitation loop, so that the excitation module 4 can send a stable excitation signal to the battery after receiving the detection signal of the BMS, so as to obtain a more accurate response signal of the battery pack 1 and realize more accurate impedance detection.

[0052] In some embodiments, the current stabilizing module 3 includes a current stabilizing unit 31, a current control resistor 32 and an operational amplifier 34. The first input end of the current stabilizing unit 31 is connected to the second end of the switch module 2; the second input end of the current stabilizing unit 31 is connected to the output end of the operational amplifier 34, for receiving an amplified signal of the operational amplifier 34 and generating a first current signal according to the amplified signal; the output end of the current stabilizing unit 31 is connected to the first end of the current control resistor 32, for sending the generated first current signal to the current control resistor 32, and the second end of the current control resistor 32 is electrically connected to the first end of the excitation module 4.

[0053] In addition, the first input end of the operational amplifier 34 is connected to the first end of the current control resistor 32, the second input end of the operational amplifier 34 is connected to the second end of the current control resistor 32, for receiving the first current signal flowing through the current control resistor 32 and generating an amplified signal, and the output end of the operational amplifier 34 is connected to the second input end of the current stabilizing unit 31, for sending the amplified signal to the current stabilizing unit 31.

[0054] Through the above arrangement, the operational amplifier 34 can send the first current signal flowing through the current control resistor 32 to the current stabilizing unit 31 to generate an amplified signal, so that the current stabilizing unit 31 adjusts the first current signal fed back to the current control resistor 32 according to the amplified signal, so that the current remains constant, avoiding the problem of instantaneous excessive current due to too low voltage of the battery pack 1, and further capable of inputting a stable excitation signal to the excitation module 4.

[0055] In some embodiments, the current control resistor 32 is connected to the positive electrode of the current stabilizing diode 33, and the negative electrode of the current stabilizing diode 33 is connected to the positive electrode of the battery pack 1.

[0056] In some embodiments, the first end of the current stabilizing module 3 is connected to the first end of the output module 6, configured to receive a charging current of the output module 6 when the output module 6 is connected to a charging power supply. The third end of the current stabilizing module 3 is connected to the first end of the battery pack 1, configured to pre-charge the battery pack 1 when the output module 6 is connected to the charging power supply.

[0057] Specifically, the first end of the current stabilizing unit 31 is connected to the first end of the output module 6, configured to receive a charging current. The current stabilizing module 3 further includes a current stabilizing diode 33, the positive electrode of the current stabilizing diode 33 is connected to the second end of the current control resistor 32, and the negative electrode of the current stabilizing diode 33 is connected to the first end of the battery pack 1.

[0058] When charging the battery pack 1, the output end is connected to a charging power supply, and the switch assembly is first disconnected. At this time, the charging current of the charging power supply can pass through the current stabilizing unit 31, the current control resistor 32 and the operational amplifier 34 in sequence, and the three cooperate to adjust the current size, and finally the stable current is input to the battery pack 1 through the current stabilizing diode 33, so as to realize the pre-charging of the battery pack 1. After pre-charging, the switch assembly is directly closed to charge the battery pack 1.

[0059] In some embodiments, the excitation module 4 includes an excitation switch and an excitation resistor 42, wherein the first end of the excitation resistor 42 is connected to the second end of the current stabilizing module 3, specifically the second end of the current control resistor 32; the second end of the excitation resistor 42 is connected to the first end of the excitation switch. The second end of the excitation switch is connected to the second end of the battery pack 1, and the third end of the excitation switch is connected to the BMS, which is configured to receive a detection signal and close or open according to the detection signal, and send an excitation signal to the battery pack 1.

[0060] When detecting the impedance of the battery pack 1, the switch assembly is closed, the output module 6 is idle, and the excitation switch receives the detection signal of the BMS and closes or opens according to the detection signal at a certain frequency. When the excitation switch is closed, the current of the battery pack 1 flows to the negative electrode of the battery pack 1 through the switch module, the current stabilizing module 3 and the excitation module 4, and when the excitation switch is opened, the above-mentioned loop is disconnected. By switching the closing and opening of the excitation switch at a certain frequency, a stable excitation signal can be sent to the battery pack 1.

[0061] Specifically, the above-mentioned excitation switch is an N-type excitation MOS tube 41, the drain of the excitation MOS tube 41 is connected to the second end of the excitation resistor 42, the source of the excitation MOS tube 41 is connected to the negative electrode of the battery pack 1, and the gate of the excitation MOS tube 41 is connected to the BMS for receiving the switching signal sent by the BMS and closing or opening according to the switching signal.

[0062] In some embodiments, the switch module 2 further includes an N-type first MOS tube 21, an N-type second MOS tube 22, a first diode and a second diode, wherein the drain of the first MOS tube 21 is connected to the positive electrode of the battery pack 1, the source of the first MOS tube 21 is connected to the source of the second MOS tube 22, and the drain of the second MOS tube 22 is connected to the output module 6 and the current stabilizing module 3. The gates of the first MOS tube 21 and the second MOS tube 22 are connected to the BMS for receiving the switching signal of the BMS and closing or opening according to the switching signal, the positive electrode of the first diode is connected to the source of the first MOS tube 21, the negative electrode of the first diode is connected to the drain of the first MOS tube 21, the positive electrode of the second diode is connected to the source of the second MOS tube 22, and the negative electrode of the second diode is connected to the drain of the second MOS tube 22.

[0063] Through the above setting, when the battery pack 1 is charged, the output module 6 is connected to the charging power supply, the first MOS tube 21 and the second MOS tube 22 are both opened by the BMS control, the charging power supply first pre-charges the battery pack 1 through the current stabilizing unit 31, so as to avoid the problem that the instantaneous charging current is too large due to the too low voltage of the battery pack 1; and then the second MOS tube 22 is closed by the BMS control, so that the current sequentially passes through the second MOS tube 22 and the first diode to charge the battery pack 1.

[0064] In addition, when the battery pack 1 needs to be detected, the first MOS tube 21 is closed and the second MOS tube 22 is opened by the BMS control, and the detection signal is sent to the excitation MOS tube 41 by the BMS, so that the current of the battery pack 1 sequentially passes through the first MOS tube 21, the second diode, the current stabilizing module 3 and the excitation module 4, so as to realize sending the excitation signal to the battery pack 1.

[0065] In the embodiment, the circuit further comprises a discharging module 5, the first end of the discharging module 5 is connected to the first end of the battery pack 1, the second end of the discharging module 5 is connected to the first end of the output module 6, and the second end of the output module 6 is connected to the second end of the battery pack 1. The battery pack 1, the discharging module 5, the output module 6 and the load can constitute a loop. The discharging module 5 is configured to turn on the connection between the battery pack 1 and the output module 6 when the load is connected to the output end, at this time, the first MOS tube 21 and the second MOS tube 22 on the switch module 2 are both in the off state, so that the battery pack 1 supplies power to the external load.

[0066] It should be noted that the above only describes the preferred embodiments of the present application and should not be used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A battery malfunction diagnostic circuit, characterized in that, Includes battery pack, BMS, switching module, current stabilization module, excitation module, and output module; The output module is connected to a load or a charging power supply; The first end of the switch module is connected to the first end of the battery pack, and the second end of the switch module is connected to the first end of the output module, for conducting the electrical connection between the battery pack and the output module; The first terminal of the current stabilizing module is connected to the second terminal of the switching module, and the second terminal of the current stabilizing module is connected to the first terminal of the excitation module, for the purpose of stabilizing the current; The second end of the excitation module is connected to the second end of the battery pack, and the third end of the excitation module is connected to the BMS. It is configured to receive the detection signal from the BMS and send an excitation signal to the battery pack. The BMS is configured to send a detection signal to the excitation module.

2. The battery malfunction diagnostic circuit according to claim 1, characterized in that, The current stabilization module includes a current stabilization unit, a current control resistor, and an operational amplifier; The first input terminal of the current stabilizing unit is connected to the second terminal of the switching module; the second input terminal of the current stabilizing unit is connected to the output terminal of the operational amplifier, and is used to receive the amplified signal of the operational amplifier and generate a first current signal according to the amplified signal. The first end of the current control resistor is connected to the output end of the current stabilizing unit, and the second end is electrically connected to the first end of the excitation module. The first input terminal of the operational amplifier is connected to the first terminal of the current-controlling resistor, and the second input terminal of the operational amplifier is connected to the second terminal of the current-controlling resistor, for receiving the first current signal flowing through the current-controlling resistor and generating an amplified signal; The output terminal of the operational amplifier is connected to the second input terminal of the current stabilizing unit, and is used to send the amplified signal to the current stabilizing unit.

3. The battery malfunction diagnostic circuit according to claim 2, characterized in that, The first terminal of the current stabilizing module is connected to the first terminal of the output module and is configured to receive charging current when the output module is connected to a charging power supply; the third terminal of the current stabilizing module is connected to the first terminal of the battery pack and is configured to precharge the battery pack when the output module is connected to the charging power supply.

4. The battery malfunction diagnostic circuit according to claim 3, characterized in that, The first end of the current stabilizing unit is connected to the first end of the output module and is configured to receive charging current when the output module is connected to a charging power supply; the current stabilizing module also includes a current stabilizing diode, the anode of the current stabilizing diode is connected to the second end of the current control resistor, and the cathode of the current stabilizing diode is connected to the first end of the battery pack.

5. A battery malfunction diagnostic circuit according to claim 1, characterized in that, The excitation module includes an excitation switch and an excitation resistor; The first end of the excitation resistor is connected to the second end of the current stabilization module, and the second end of the excitation resistor is connected to the first end of the excitation switch. The second end of the excitation switch is connected to the second end of the battery, and the third end of the excitation switch is connected to the BMS. It is configured to receive the detection signal and send an excitation signal to the battery pack according to whether the detection signal is closed or open.

6. The battery malfunction diagnostic circuit according to claim 5, characterized in that, The excitation switch is an N-type excitation MOSFET. The drain of the excitation MOSFET is connected to the second terminal of the excitation resistor. The source of the excitation MOSFET is connected to the negative terminal of the battery pack. The gate of the excitation MOSFET is connected to the BMS and is used to receive the switching signal sent by the BMS and to close or open the switch according to the switching signal.

7. The battery malfunction diagnostic circuit according to claim 1, characterized in that, The switching module also includes an N-type first MOSFET, an N-type second MOSFET, a first diode, and a second diode; The drain of the first MOSFET is connected to the positive terminal of the battery pack, the source of the first MOSFET is connected to the source of the second MOSFET, and the drain of the second MOSFET is connected to the output module and the current stabilization module.

8. A battery malfunction diagnostic circuit according to claim 7, characterized in that, The gates of the first MOS transistor and the second MOS transistor are both connected to the BMS to receive the switching signal from the BMS and to close or open the circuit according to the switching signal.

9. A battery malfunction diagnostic circuit according to claim 8, characterized in that, The anode of the first diode is connected to the source of the first MOSFET, and the cathode of the first diode is connected to the drain of the first MOSFET. The positive terminal of the second diode is connected to the source of the second MOSFET, and the negative terminal of the second diode is connected to the drain of the second MOSFET.

10. A battery malfunction diagnostic circuit according to any one of claims 1 to 9, characterized in that, It also includes a discharge module, the first end of which is connected to the first end of the battery pack, and the second end of which is connected to the output module, for connecting the battery pack to the output module when the output module is connected to a load.

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