Battery pack load detection circuit and system

Abstract

The utility model relates to the technical field of electronic circuits, and particularly provides a battery pack load detection circuit and system, and the battery pack load detection circuit comprises a detection module and a pre-charging module. The detection module is used for detecting the working voltage on the load when the battery pack supplies power to the load and inputting the working voltage to the controller; and the pre-charging module is used for receiving a control signal output by the controller when the controller determines that the working voltage is not in a preset voltage range, and disconnecting the battery pack from the load based on the control signal. On the basis, the voltage on the load is detected in real time through the detection module, detection through devices such as a sensor is avoided, so that the detection precision is improved, whether power is supplied to the load or not is controlled through the pre-charging module, when the load breaks down, connection between the load and the battery pack is immediately disconnected, and then safety accidents are avoided; and the safety of the battery pack is improved.

Description

[Technical field]

[0001] The utility model relates to the technical field of electronic circuits, and in particular to a battery pack load detection circuit and system. [Background technology]

[0002] BMS battery management system, commonly known as battery nanny or battery butler. It is a device or software used to monitor, control and protect batteries. It is usually used in battery packs, such as power battery packs in electric vehicles or energy storage battery packs in energy storage systems. The main goal of BMS is to ensure the safety and performance of the battery pack and maximize the service life of the battery.

[0003] With the popularization and expansion of battery applications, the safety requirements for batteries are becoming higher and higher. Load monitoring, as one of the important functions of BMS, can monitor the load of the battery in real time during operation to prevent safety problems such as overcurrent, overvoltage, and overtemperature.

[0004] The existing BMS battery management system monitors loads through traditional data collection methods such as current sensors and voltage sensors. Due to factors such as the accuracy, stability and calibration of the sensors themselves, the monitored load data may have certain errors, affecting the accurate judgment of the load conditions, thereby reducing the safety, life and reliability of the battery system. [Utility Model Content]

[0005] The present invention provides a battery pack load detection circuit and system, aiming to solve the technical problem of low battery pack safety caused by low accuracy and poor stability of load monitoring by the BMS battery management system in the prior art.

[0006] In order to solve the above technical problems, a technical solution adopted by the embodiment of the utility model is: providing a battery pack load detection circuit, the battery pack load detection circuit comprising a detection module and a pre-charging module;

[0007] The first end of the detection module is connected to the positive electrode of the battery pack and the positive electrode of the load respectively, the second end of the detection module is connected to the negative electrode of the load, and the second end of the detection module is also connected to the negative electrode of the battery pack through the pre-charging module, and the control ends of the detection module and the pre-charging module are both connected to the controller;

[0008] The detection module is used to detect the working voltage on the load when the battery pack supplies power to the load, and input the working voltage to the controller;

[0009] The pre-charging module is used to receive a control signal output by the controller when the controller determines that the operating voltage is not within a preset voltage range, and disconnect the battery pack from the load based on the control signal.

[0010] Optionally, the detection module includes a voltage divider unit, an isolation unit and an operational amplifier unit;

[0011] The voltage dividing unit is connected to the load, the voltage dividing unit is also connected to the input end of the isolation unit, the output end of the isolation unit is connected to the input end of the operational amplifier unit, and the output end of the operational amplifier unit is connected to the controller;

[0012] The voltage dividing unit is used to detect the working voltage on the load and divide the working voltage;

[0013] The isolation unit is used to receive the divided working voltage, and output the divided working voltage to the controller through the operational amplifier unit, so that the controller determines whether to output a control signal to the pre-charging module.

[0014] Optionally, the voltage dividing unit includes a resistor R372, a resistor R373, a resistor R374, a resistor R375 and a resistor R380;

[0015] The resistor R375 is connected to the positive electrode of the load, and is connected in series with the resistor R374, the resistor R373 and the resistor R372. The resistor R372 is also connected to the input end of the isolation unit and the resistor R380 respectively, and the resistor R380 is also connected to the negative electrode of the load.

[0016] Optionally, the isolation unit includes an isolation chip U22, a capacitor C237, a capacitor C238, a resistor R378 and a resistor R379;

[0017] The first pin of the isolation chip U22 is connected to the first voltage, the eighth pin of the isolation chip U22 is connected to the second voltage, the capacitor C238 is connected to the first voltage and the ground terminal respectively, the capacitor C237 is connected to the second voltage and the ground terminal respectively, the second pin of the isolation chip U22 is connected to the resistor R372, the sixth pin of the isolation chip U22 is connected to the operational amplifier unit through the resistor R379, and the seventh pin of the isolation chip U22 is connected to the operational amplifier unit through the resistor R378.

[0018] Optionally, the operational amplifier unit includes an operational amplifier U23, a resistor R381 and a resistor R376;

[0019] The positive input terminal of the operational amplifier U23 is connected to the resistor R378, the negative input terminal of the operational amplifier U23 is connected to the resistor R379, the output terminal of the operational amplifier U23 is connected to the controller through the resistor R376, and the output terminal of the operational amplifier U23 is also connected to the negative input terminal of the operational amplifier U23 through the resistor R381.

[0020] Optionally, the pre-charging module includes a control unit and a pre-charging unit;

[0021] The control end of the control unit is connected to the controller, the first end of the control unit is connected to the negative electrode of the load through the pre-charging unit, and the second end of the control unit is connected to the negative electrode of the battery pack;

[0022] The control unit is used to receive a control signal output by the controller, and control the pre-charging unit to be in a cut-off state based on the control signal to disconnect the battery pack from the load.

[0023] Optionally, the control unit includes a switch tube Q10, a switch tube Q9, a switch tube Q12, a resistor R131, a resistor R124 and a resistor R123;

[0024] The control end of the switch tube Q10 is connected to the controller through the resistor R131, the first end of the switch tube Q10 is connected to the control end of the switch tube Q9, the first end of the switch tube Q10 is also connected to the third voltage through the resistor R124, the second end of the switch tube Q10 is used for grounding, the first end of the switch tube Q9 is connected to the third voltage through the resistor R123, the second end of the switch tube Q9 is connected to the control end of the switch tube Q12, the first end of the switch tube Q12 is connected to the pre-charging unit, and the second end of the switch tube Q12 is used for grounding.

[0025] Optionally, the control unit further includes a voltage regulator tube D37 and a voltage regulator tube D60;

[0026] The cathode of the voltage regulator tube D37 is connected to the control end of the switch tube Q12, the anode of the voltage regulator tube D37 is connected to the negative electrode of the battery pack, the anode of the voltage regulator tube D60 is connected to the control end of the switch tube Q9, and the cathode of the voltage regulator tube D60 is connected to the resistor R123.

[0027] Optionally, the pre-charging unit includes a resistor R119, a resistor R120, a resistor R121, a resistor R122, a resistor R126, a resistor R127, a resistor R128, and a resistor R129;

[0028] The resistor R119 is connected to the negative electrode of the load, the resistor R119 is connected in series with the resistor R126, the resistor R126 is connected to the first end of the switch tube Q12, the resistor R120 is connected to the negative electrode of the load, the resistor R120 is connected in series with the resistor R127, the resistor R127 is connected to the first end of the switch tube Q12, the resistor R121 is connected to the negative electrode of the load, the resistor R121 is connected in series with the resistor R128, the resistor R128 is connected to the first end of the switch tube Q12, the resistor R122 is connected to the negative electrode of the load, the resistor R122 is connected in series with the resistor R129, and the resistor R129 is connected to the first end of the switch tube Q12.

[0029] In order to solve the above technical problems, another technical solution adopted by the embodiment of the utility model is: to provide a battery pack load detection system, the battery pack load detection system comprising:

[0030] controller; battery pack; and

[0031] A battery pack load detection circuit as described above.

[0032] Different from the related art, the embodiment of the utility model provides a battery pack load detection circuit and system, the battery pack load detection circuit includes a detection module and a pre-charging module; the first end of the detection module is connected to the positive electrode of the battery pack and the positive electrode of the load respectively, the second end of the detection module is connected to the negative electrode of the load, and the second end of the detection module is also connected to the negative electrode of the battery pack through the pre-charging module, and the control ends of the detection module and the pre-charging module are both connected to the controller; the detection module is used to detect the working voltage on the load when the battery pack supplies power to the load, and input the working voltage to the controller; the pre-charging module is used to receive the control signal output by the controller when the controller determines that the working voltage is not within the preset voltage range, and disconnect the battery pack from the load based on the control signal. Based on this, the voltage on the load is detected in real time by the detection module, avoiding the use of sensors and other devices for detection, thereby improving the detection accuracy, and controlling whether to supply power to the load by the pre-charging module, so that when the load fails, the connection between the load and the battery pack is immediately disconnected, thereby avoiding safety accidents and improving the safety of the battery pack.

Brief Description of the Drawings

[0033] One or more embodiments are exemplarily described by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and the figures in the drawings do not constitute proportional limitations unless otherwise stated.

[0034] Figure 1 This is an application scenario provided by an embodiment of the utility model;

[0035] Figure 2 It is a structural block diagram of a battery pack load detection circuit provided by an embodiment of the utility model;

[0036] Figure 3 It is a circuit diagram of a detection module provided by an embodiment of the utility model;

[0037] Figure 4 It is a circuit diagram of a pre-charging module provided in an embodiment of the utility model. [Specific implementation method]

[0038] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0039] The technical features involved in the various embodiments of the present application described below do not conflict with each other and can be combined with each other.

[0040] When an element is referred to as being “connected to” another element, it can be directly connected to the other element, or one or more intervening elements may be present therebetween.

[0041] The terms "first", "second", etc. in the specification and claims of the present utility model are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more.

[0042] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not used to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0043] See also Figure 1 , Figure 1 This is an application scenario provided by the embodiment of the utility model, such as Figure 1As shown, the application scenario 1 includes a battery pack load detection system 100 and a load 200, and the battery pack load detection system 100 is used to connect to the load 200. The battery pack load detection system 100 includes a battery pack load detection circuit 10, a controller 20 and a battery pack 30; the battery pack load detection circuit 10 is connected to the controller 20 and the battery pack 30 respectively, and the battery pack load detection circuit 10 is also used to connect to the load 200.

[0044] Specifically, when the battery pack load detection circuit 10 is connected to the load 200, the battery pack 30 starts to supply power to the load 200. At this time, the battery pack load detection circuit 10 will detect the operating voltage on the load 200 in real time, and send the operating voltage to the controller 20, so as to disconnect the battery pack 30 from the load 200 when the operating voltage is not within the preset negative voltage range, thereby stopping the load 200 from working, thereby ensuring the safety of the battery pack 30 and improving the service life and reliability of the battery pack 20. It should be noted that when the load 200 is working normally, the battery pack 30 will normally supply power to the load 200. Once the battery pack load detection circuit 10 detects that the operating voltage on the load 200 has jumped, the controller 20 will determine whether the operating voltage is within a preset voltage range. If not, the battery pack load detection circuit 10 will be controlled to disconnect the battery pack 30 from the load 200, thereby avoiding a fire caused by still supplying power to the load 200 when a fault occurs in the load 200, thereby improving the safety of the battery pack 30.

[0045] See also Figure 2 , Figure 2 is a structural block diagram of a battery pack load detection circuit provided by an embodiment of the utility model, such as Figure 2 As shown, the battery pack load detection circuit 10 includes a detection module 11 and a pre-charging module 12;

[0046] The first end of the detection module 11 is connected to the positive electrode of the battery pack 30 and the positive electrode of the load 200 respectively, the second end of the detection module 11 is connected to the negative electrode of the load 200, and the second end of the detection module 11 is also connected to the negative electrode of the battery pack 30 through the pre-charging module 12, and the control ends of the detection module 11 and the pre-charging module 12 are both connected to the controller 20;

[0047] The detection module 11 is used to detect the working voltage on the load 200 when the battery pack 30 supplies power to the load 200, and input the working voltage to the controller 20;

[0048] The pre-charging module 12 is used to receive a control signal output by the controller 20 when the controller 20 determines that the operating voltage is not within a preset voltage range, and disconnect the battery pack 30 from the load 200 based on the control signal.

[0049] It should be noted that the preset voltage range is set according to the voltage of the load 200 when it is working normally, for example, it is set according to the rated voltage of the load 200. When the working voltage of the load 200 is not within the preset voltage range, the load 200 has at least two situations. For example, when the load 200 is short-circuited, the load 200 is equivalent to a straight line (that is, the resistance value on the load 200 is particularly small). At this time, according to Ohm's law, the voltage on the load 200 will also be particularly small. When the detection module 11 detects the working voltage on the load 200, the controller 20 will find that the voltage on the load 200 is less than the preset voltage range. Therefore, the controller 20 will output a control signal to disconnect the load 200 from the battery pack 30. For another example, when the load 200 is short-circuited, the voltage on the load 200 will be particularly large. At this time, the controller 20 will also output a control signal to the pre-charging module 12 to disconnect the load 200 from the battery pack 30.

[0050] In some embodiments, when the operating voltage of the load 200 is within the preset voltage range, the controller 20 outputs a driving signal to the pre-charging module 12 so that the pre-charging module 12 normally transmits the voltage output by the battery pack 30 to the load 200 according to the driving signal.

[0051] In some embodiments, Figure 2 As shown, the detection module 11 includes a voltage dividing unit 111, an isolation unit 112 and an operational amplifier unit 113; the voltage dividing unit 111 is connected to the load 200, the voltage dividing unit 111 is also connected to the input end of the isolation unit 112, the output end of the isolation unit 112 is connected to the input end of the operational amplifier unit 113, and the output end of the operational amplifier unit 113 is connected to the controller 20;

[0052] The voltage dividing unit 111 is used to detect the working voltage on the load 200 and divide the working voltage;

[0053] The isolation unit 112 is used to receive the divided working voltage, and output the divided working voltage to the controller 20 through the operational amplifier unit 113, so that the controller 20 determines whether to output a control signal to the pre-charge module 12. It should be noted that the voltage divider unit 111 is mainly used to divide the working voltage on the load 200, and the isolation unit 112 is mainly used to isolate the divided working voltage to prevent electrical interference from causing errors in the detected voltage; and outputting the isolated working voltage through the isolation unit 112 through the operational amplifier unit 113 can further improve the stability of the collected working voltage, thereby improving the reliability and safety of the battery pack 30.

[0054] For details, please refer to Figure 3 , Figure 3 is a circuit diagram of a detection module provided by an embodiment of the utility model, such as Figure 3 As shown, the voltage divider unit 111 includes a resistor R372, a resistor R373, a resistor R374, a resistor R375 and a resistor R380; the resistor R375 is connected to the positive electrode of the load 200, the resistor R375 is connected in series with the resistor R374, the resistor R373 and the resistor R372, the resistor R372 is also connected to the input end of the isolation unit 112 and the resistor R380, respectively, and the resistor R380 is also connected to the negative electrode of the load 200. It should be noted that when the load 200 starts to work based on the working voltage output by the battery pack 30, the resistor R380 will divide the working voltage on the load 200 with the resistor R372, the resistor R373, the resistor R374 and the resistor R375, and input the divided voltage to the input end of the isolation unit 112, wherein the divided voltage is the voltage on the resistor R380.

[0055] In some embodiments, Figure 3As shown, the voltage dividing unit 111 further includes a diode D62 and a voltage regulator tube D123; the anode of the diode D62 is connected to the positive electrode of the load 200, and the cathode of the diode D62 is connected to the first end of the resistor R375; the cathodes of most voltage regulator tubes D123 are connected to the resistor R373, and the anodes of the voltage regulator tubes D123 are connected to the negative electrode of the load 200. Among them, the diode D62 is an anti-reverse diode, which is mainly used to prevent the current of the isolation unit 112 from flowing back into the load 200. The voltage regulator tube D123 is mainly used to prevent the operating voltage on the load 200 from being too large and damaging the isolation unit 112; specifically, when the operating voltage on the load 200 is too large, the voltage regulator tube D123 will be broken down first, so that the current on the load 200 directly flows into the ground terminal, so as to avoid large current input into the isolation unit 112 and damaging the isolation unit 112.

[0056] For further information, see Figure 3 , the isolation unit 112 includes an isolation chip U22, a capacitor C237, a capacitor C238, a resistor R378 and a resistor R379;

[0057] The first pin of the isolation chip U22 is connected to the first voltage 51, the eighth pin of the isolation chip U22 is connected to the second voltage 52, the capacitor C238 is connected to the first voltage 51 and the ground terminal respectively, the capacitor C237 is connected to the second voltage 52 and the ground terminal respectively, the second pin of the isolation chip U22 is connected to the resistor R372, the sixth pin of the isolation chip U22 is connected to the operational amplifier unit 113 through the resistor R379, and the seventh pin of the isolation chip U22 is connected to the operational amplifier unit 113 through the resistor R378. It should be noted that the first voltage 51 and the second voltage 52 are two power supply voltages with different voltage values, and different power supply voltages and ground terminals are connected to the 1 (right side of the isolation chip) and 2 (left side of the isolation chip) sides of the isolation chip U22, so that the 1 and 2 sides of the isolation chip U22 are completely isolated, thereby achieving the effect of isolation protection. Optionally, the first voltage 51 is 5V and the second voltage 52 is 3.3V.

[0058] like Figure 3As shown, the operational amplifier unit 113 includes an operational amplifier U23, a resistor R381 and a resistor R376; the positive input terminal of the operational amplifier U23 is connected to the resistor R378, the reverse input terminal of the operational amplifier U23 is connected to the resistor R379, the output terminal of the operational amplifier U23 is connected to the controller through the resistor R376, and the output terminal of the operational amplifier U23 is also connected to the reverse input terminal of the operational amplifier U23 through the resistor R381. It should be noted that the operational amplifier U23 is 1 times amplified, that is, the output is equal to the input, and two voltages are output to the operational amplifier U23 through the isolation chip U22, so that the operational amplifier U23 is a differential amplifier, so that the working voltage output by the operational amplifier U23 is more stable, thereby improving the detection accuracy.

[0059] In some embodiments, Figure 2 As shown, the pre-charging module 12 includes a control unit 121 and a pre-charging unit 122;

[0060] The control end of the control unit 121 is connected to the controller 20, the first end of the control unit 121 is connected to the negative electrode of the load 200 through the pre-charging unit 122, and the second end of the control unit 121 is connected to the negative electrode of the battery pack 30;

[0061] The control unit 121 is used to receive a control signal output by the controller 20 , and control the pre-charging unit 122 to be in a cut-off state based on the control signal, so as to disconnect the battery pack 30 from the load 200 .

[0062] For details, please refer to Figure 4 , Figure 4 is a circuit diagram of a pre-charge module provided by an embodiment of the utility model, such as Figure 4 As shown, the control unit 121 includes a switch tube Q10, a switch tube Q9, a switch tube Q12, a resistor R131, a resistor R124 and a resistor R123; the control end of the switch tube Q10 is connected to the controller 20 through the resistor R131, the first end of the switch tube Q10 is connected to the control end of the switch tube Q9, the first end of the switch tube Q10 is also connected to the third voltage 53 through the resistor R124, the second end of the switch tube Q10 is used for grounding, the first end of the switch tube Q9 is connected to the third voltage 53 through the resistor R123, the second end of the switch tube Q9 is connected to the control end of the switch tube Q12, the first end of the switch tube Q12 is connected to the pre-charging unit 122, and the second end of the switch tube Q12 is used for grounding.

[0063] Specifically, the switch tube Q10 is used to receive the drive signal output by the controller 20 through the resistor R131 when the operating voltage on the load 200 is within the preset voltage range, and is in a conductive state based on the drive signal. When the switch tube Q10 is turned on, the switch tube Q9 is also turned on. At this time, the control end of the switch tube Q12 is connected to the third voltage 53 through the resistor R123, and the switch tube Q12 is also turned on. When the switch tube Q12 is turned on, the negative electrode of the battery pack 30 is connected to the negative electrode of the load 200 through the pre-charging unit 122, so that the load 200 receives the voltage output by the battery pack 30 through the pre-charging unit 122. Once it is detected that the voltage on the load 200 is not within the preset voltage range, the switch tube Q10 will be in the cut-off state based on the control signal, so that there is no voltage difference across the GS of the switch tube Q9, and the switch tube Q9 is also cut off. When the switch tube Q9 is cut off, the switch tube Q12 is also cut off, so that the negative electrode of the load 200 is disconnected from the negative electrode of the battery pack 30.

[0064] Optionally, when the switch tube Q10 is an NPN-type transistor, the drive signal is a high-level signal, and the control signal is a low-level signal.

[0065] In some embodiments, Figure 4 As shown, the control unit further includes a voltage regulator tube D37 and a voltage regulator tube D60; the cathode of the voltage regulator tube D37 is connected to the control end of the switch tube Q12, the anode of the voltage regulator tube D37 is connected to the negative electrode of the battery pack, the anode of the voltage regulator tube D60 is connected to the control end of the switch tube Q9, and the cathode of the voltage regulator tube D60 is connected to the resistor R123. It should be noted that the voltage regulator tube D37 and the voltage regulator tube D60 are clamping diodes, which are mainly used to protect the switch tube Q9 and the switch tube Q12 from being damaged when the voltage of the third voltage 53 is too large.

[0066] Further, such as Figure 4As shown, the pre-charge unit includes a resistor R119, a resistor R120, a resistor R121, a resistor R122, a resistor R126, a resistor R127, a resistor R128, and a resistor R129; the resistor R119 is connected to the negative electrode of the load 200, the resistor R119 is connected in series with the resistor R126, the resistor R126 is connected to the first end of the switch tube Q12, the resistor R120 is connected to the negative electrode of the load 200, and the resistor R120 is connected to the The resistor R127 is connected in series, the resistor R127 is connected to the first end of the switch tube Q12, the resistor R121 is connected to the negative electrode of the load 200, the resistor R121 is connected in series with the resistor R128, the resistor R128 is connected to the first end of the switch tube Q12, the resistor R122 is connected to the negative electrode of the load 200, the resistor R122 is connected in series with the resistor R129, and the resistor R129 is connected to the first end of the switch tube Q12. When the switch tube Q12 is turned on, the voltage of the battery pack 30 will be input into the load 200 through the resistor in the pre-charging unit 122. It should be noted that the resistors in the pre-charging unit 122 include series and parallel connections. According to the characteristics of series voltage division and parallel current division, it is ensured that no matter the load 200 is in a short circuit or an open circuit, the large current or voltage in the circuit can be consumed, thereby protecting the devices in the circuit from damage, thereby improving the safety of the battery pack 30.

[0067] The utility model provides a battery pack load detection circuit, which includes a detection module and a pre-charging module; the first end of the detection module is connected to the positive electrode of the battery pack and the positive electrode of the load respectively, the second end of the detection module is connected to the negative electrode of the load, and the second end of the detection module is also connected to the negative electrode of the battery pack through the pre-charging module, and the control ends of the detection module and the pre-charging module are both connected to a controller; the detection module is used to detect the working voltage on the load when the battery pack supplies power to the load, and input the working voltage to the controller; the pre-charging module is used to receive the control signal output by the controller when the controller determines that the working voltage is not within a preset voltage range, and disconnect the battery pack from the load based on the control signal. Based on this, the voltage on the load is detected in real time by the detection module, avoiding the use of sensors and other devices for detection, thereby improving the accuracy of detection, and controlling whether to supply power to the load by the pre-charging module, so that when the load fails, the connection between the load and the battery pack is immediately disconnected, thereby avoiding safety accidents and improving the safety of the battery pack.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of ​​the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pack load detection circuit, characterized in that: The battery pack load detection circuit includes a detection module and a pre-charging module; The first end of the detection module is connected to the positive electrode of the battery pack and the positive electrode of the load respectively, the second end of the detection module is connected to the negative electrode of the load, and the second end of the detection module is also connected to the negative electrode of the battery pack through the pre-charging module, and the control ends of the detection module and the pre-charging module are both connected to the controller; The detection module is used to detect the working voltage on the load when the battery pack supplies power to the load, and input the working voltage to the controller; The pre-charging module is used to receive a control signal output by the controller when the controller determines that the operating voltage is not within a preset voltage range, and disconnect the battery pack from the load based on the control signal.

2. The battery pack load detection circuit according to claim 1, characterized in that: The detection module includes a voltage dividing unit, an isolation unit and an operational amplifier unit; The voltage dividing unit is connected to the load, the voltage dividing unit is also connected to the input end of the isolation unit, the output end of the isolation unit is connected to the input end of the operational amplifier unit, and the output end of the operational amplifier unit is connected to the controller; The voltage dividing unit is used to detect the working voltage on the load and divide the working voltage; The isolation unit is used to receive the divided working voltage, and output the divided working voltage to the controller through the operational amplifier unit, so that the controller determines whether to output a control signal to the pre-charging module.

3. The battery pack load detection circuit according to claim 2, characterized in that: The voltage dividing unit includes a resistor R372, a resistor R373, a resistor R374, a resistor R375 and a resistor R380; The resistor R375 is connected to the positive electrode of the load, and is connected in series with the resistor R374, the resistor R373 and the resistor R372. The resistor R372 is also connected to the input end of the isolation unit and the resistor R380 respectively, and the resistor R380 is also connected to the negative electrode of the load.

4. The battery pack load detection circuit according to claim 3, characterized in that: The isolation unit includes an isolation chip U22, a capacitor C237, a capacitor C238, a resistor R378 and a resistor R379; The first pin of the isolation chip U22 is connected to the first voltage, the eighth pin of the isolation chip U22 is connected to the second voltage, the capacitor C238 is connected to the first voltage and the ground terminal respectively, the capacitor C237 is connected to the second voltage and the ground terminal respectively, the second pin of the isolation chip U22 is connected to the resistor R372, the sixth pin of the isolation chip U22 is connected to the operational amplifier unit through the resistor R379, and the seventh pin of the isolation chip U22 is connected to the operational amplifier unit through the resistor R378.

5. The battery pack load detection circuit according to claim 4, characterized in that: The operational amplifier unit includes an operational amplifier U23, a resistor R381 and a resistor R376; The positive input terminal of the operational amplifier U23 is connected to the resistor R378, the negative input terminal of the operational amplifier U23 is connected to the resistor R379, the output terminal of the operational amplifier U23 is connected to the controller through the resistor R376, and the output terminal of the operational amplifier U23 is also connected to the negative input terminal of the operational amplifier U23 through the resistor R381.

6. The battery pack load detection circuit according to claim 1, characterized in that: The pre-charging module comprises a control unit and a pre-charging unit; The control end of the control unit is connected to the controller, the first end of the control unit is connected to the negative electrode of the load through the pre-charging unit, and the second end of the control unit is connected to the negative electrode of the battery pack; The control unit is used to receive a control signal output by the controller, and control the pre-charging unit to be in a cut-off state based on the control signal to disconnect the battery pack from the load.

7. The battery pack load detection circuit according to claim 6, characterized in that: The control unit includes a switch tube Q10, a switch tube Q9, a switch tube Q12, a resistor R131, a resistor R124 and a resistor R123; The control end of the switch tube Q10 is connected to the controller through the resistor R131, the first end of the switch tube Q10 is connected to the control end of the switch tube Q9, the first end of the switch tube Q10 is also connected to the third voltage through the resistor R124, the second end of the switch tube Q10 is used for grounding, the first end of the switch tube Q9 is connected to the third voltage through the resistor R123, the second end of the switch tube Q9 is connected to the control end of the switch tube Q12, the first end of the switch tube Q12 is connected to the pre-charging unit, and the second end of the switch tube Q12 is used for grounding.

8. The battery pack load detection circuit according to claim 7, characterized in that: The control unit also includes a voltage regulator tube D37 and a voltage regulator tube D60; The cathode of the voltage regulator tube D37 is connected to the control end of the switch tube Q12, the anode of the voltage regulator tube D37 is connected to the negative electrode of the battery pack, the anode of the voltage regulator tube D60 is connected to the control end of the switch tube Q9, and the cathode of the voltage regulator tube D60 is connected to the resistor R123.

9. The battery pack load detection circuit according to claim 7, characterized in that: The pre-charge unit includes a resistor R119, a resistor R120, a resistor R121, a resistor R122, a resistor R126, a resistor R127, a resistor R128, and a resistor R129; The resistor R119 is connected to the negative electrode of the load, the resistor R119 is connected in series with the resistor R126, the resistor R126 is connected to the first end of the switch tube Q12, the resistor R120 is connected to the negative electrode of the load, the resistor R120 is connected in series with the resistor R127, the resistor R127 is connected to the first end of the switch tube Q12, the resistor R121 is connected to the negative electrode of the load, the resistor R121 is connected in series with the resistor R128, the resistor R128 is connected to the first end of the switch tube Q12, the resistor R122 is connected to the negative electrode of the load, the resistor R122 is connected in series with the resistor R129, and the resistor R129 is connected to the first end of the switch tube Q12.

10. A battery pack load detection system, characterized in that: The battery pack load detection system comprises: Controller; Battery pack; and A battery pack load detection circuit as described in any one of claims 1 to 9.

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