MOS tube on-off state detection circuit, battery management system and battery system

Abstract

The utility model discloses an MOS tube switch state detection circuit, a battery management system and a battery system. The detection circuit comprises a voltage division module, an isolation module, an operational amplifier module, a single-chip microcomputer, a voltage reference point and a voltage sampling point. The voltage dividing module is connected to the voltage sampling point, and the voltage dividing module divides the voltage flowing into the voltage sampling point; the isolation module is connected with the voltage division module and isolates the output voltage of the voltage division module; the operational amplifier module is connected with the isolation module and the voltage reference point, compares the output voltage of the isolation module with the voltage flowing into the voltage reference point, and outputs the output voltage to the single chip microcomputer; the single-chip microcomputer is connected with the MOS tube switch to be tested. The utility model provides an MOS tube on-off state detection circuit, a battery management system and a battery system. The MOS tube on-off state detection effect can be improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly refers to a MOS tube switch state detection circuit, a battery management system and a battery system. BACKGROUND

[0002] With more and more various electrical equipment, it is becoming more and more important to improve the electrical safety of the equipment. For example, before or after the electrical equipment is connected to the power supply, the state of the power supply switch usually needs to be detected to ensure that it is in the off state.

[0003] In the actual use of the current battery energy storage project, it is necessary to know in real time whether the control MOS tube switch of the battery B-end and the load P-end is in the open state or the closed state. It is impossible to guarantee the consistency of the MOS tube switch state only by detecting the driving signal of the MOS tube. Therefore, when the MOS tube is connected to the inverter or the load, the switch state of the MOS tube is uncertain, which may cause the MOS tube or the load to be burned out, thereby bringing great safety hazards. CONTENT OF THE UTILITY MODEL

[0004] In order to overcome the defects of the prior art, the application provides a MOS tube switch state detection circuit, a battery management system and a battery system, which can improve the MOS tube switch state detection effect.

[0005] The utility model provides a MOS tube switch state detection circuit, which comprises a voltage sampling point, a voltage reference point, a single-chip microcomputer, a voltage dividing module, an isolation module and an operational amplifier module.

[0006] The voltage dividing module is connected to the voltage sampling point, and divides the voltage flowing into the voltage sampling point.

[0007] The isolation module is connected to the voltage dividing module, and isolates the output voltage of the voltage dividing module.

[0008] The operational amplifier module is connected to the isolation module and the voltage reference point, compares the output voltage of the isolation module with the voltage flowing into the voltage reference point, and outputs the comparison result to the single-chip microcomputer.

[0009] The single-chip microcomputer is connected to the MOS tube switch to be detected.

[0010] According to the MOS tube switch state detection circuit provided by the application, the voltage dividing module comprises a voltage dividing resistor.

[0011] According to the MOS tube switch state detection circuit provided by the application, the voltage dividing resistor comprises one resistor or a plurality of resistors connected in series.

[0012] The isolation module comprises a power supply unit, an isolation capacitor and an isolation diode; the isolation capacitor and the isolation diode are connected in parallel, and the power supply unit supplies power to the isolation capacitor and the isolation diode.

[0013] According to the MOS tube switch state detection circuit provided in the application, the power supply unit is a system power supply, and the isolation module isolates the system power supply into a voltage required by the operational amplifier module.

[0014] According to the MOS tube switch state detection circuit provided in the application, the operational amplifier module comprises a reference voltage input end, a sampling voltage input end and an output end.

[0015] The reference voltage input end is connected to a voltage reference point in the MOS tube switch state detection circuit.

[0016] The sampling voltage input end is connected to an output end of the isolation module.

[0017] The output end outputs an operational amplifier result.

[0018] According to the MOS tube switch state detection circuit provided in the application, the MOS tube switch state detection circuit further comprises a reference voltage module, the reference voltage module generates a reference voltage required by the operational amplifier module, and an output end of the reference voltage module is connected to the voltage reference point.

[0019] According to the MOS tube switch state detection circuit provided in the application, the MOS tube switch state detection circuit further comprises a voltage stabilizing module, the voltage stabilizing module is connected to the operational amplifier module, and the voltage stabilizing module outputs a voltage stabilizing result of the operational amplifier result output by the operational amplifier module to the single-chip microcomputer.

[0020] The application further provides a battery management system comprising a to-be-detected switch and the MOS tube switch state detection circuit provided in the application.

[0021] The application further provides a battery system comprising a battery and the battery management system provided in the application.

[0022] The MOS tube switch state detection circuit provided in the application divides the battery voltage input by a voltage sampling point, then isolates the battery voltage through an isolation module, inputs the battery voltage into an amplification and voltage stabilizing circuit, compares the sampled information with the information stored in a memory through a single-chip microcomputer, and detects the on and off states of the to-be-detected MOS tube switch. BRIEF DESCRIPTION OF DRAWINGS

[0023] The technical solutions and other beneficial effects of the present application will be apparent through the following detailed description of the specific embodiments of the present application, combined with the accompanying drawings.

[0024] Figure 1 An application schematic diagram of the MOS transistor switch state detection circuit provided in the present embodiment.

[0025] Figure 2 A structural schematic diagram of the MOS transistor switch state detection circuit provided in the present embodiment.

[0026] Figure 3 A circuit schematic diagram of the MOS transistor switch state detection circuit provided in the present embodiment.

[0027] Figure 4 A circuit structural schematic diagram of the power supply unit of the isolation module provided in the present embodiment.

[0028] Figure 5 A circuit structural schematic diagram of the reference voltage module provided in the present embodiment. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0030] In the description of the present application, it should be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise” and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms “first” and “second” are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by “first” and “second” can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of “multiple” is two or more, unless otherwise specifically limited.

[0031] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplification, the components and arrangements of the specific examples are described in the following. Of course, they are merely examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to the numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can realize the application of other processes and / or the use of other materials.

[0032] The embodiments of the present application will be further described in conjunction with the drawings and specific embodiments.

[0033] In the current battery energy storage project, it is necessary to detect in real time whether the control MOS switch between the negative electrode B- end of the battery and the negative electrode P- end of the load is in an open or closed state, but only detecting the driving signal of the MOS switch cannot guarantee the consistent state of the MOS switch. Therefore, when connecting the inverter or the load, the switching state of the MOS switch is uncertain, which can cause the MOS switch or the load to be burned out, and bring great safety hazards.

[0034] In view of the above technical problems, the present application sets a voltage dividing module, an isolation module and an operational amplifier module between the voltage reference point and the single-chip microcomputer, and judges whether the control MOS switch between the negative electrode B- end of the battery and the negative electrode P- end of the load is closed by detecting the voltage of the positive electrode B+ end of the battery and the positive electrode P+ end of the load.

[0035] The MOS switch state detection circuit disclosed in the embodiments of the present application can be used to detect the state of the switch of the target power supply, for example, to detect the state of the negative electrode switch of the target power supply, wherein the target power supply can be a high-voltage power supply in an electric device such as a vehicle. For example, the BMS (Battery Management System, battery management system) of the electric device is usually provided with a MOS switch connected with the power supply to control the on-off between the load end corresponding to the power supply and the power supply. The MOS switch state detection circuit provided by the embodiments of the present application can improve the effective recognition rate of the state of the power supply MOS switch.

[0036] Figure 1 Application schematic diagram of the MOS switch state detection circuit provided in the embodiments.

[0037] As Figure 1As shown, in this embodiment, the MOSFET switch state detection circuit is applied in a battery management system. Since the battery management system controls the negative terminal, that is, it controls the conduction and cutoff of the battery's B- terminal and the load's P- terminal by turning the MOSFET switch on and off, detecting the switching state of the MOSFET switch is crucial for the entire battery management system. In this application, the battery's B+ terminal and the load's P+ terminal of the battery management system are directly connected by a fuse (FUSE). Therefore, in this embodiment, the MOSFET switch state detection circuit is connected to the load's P+ terminal, and determines whether the MOSFET switch at the negative terminal of the battery management system is closed by detecting whether there is voltage at the load's P+ terminal. Furthermore, since the battery's B+ terminal and the load's P+ terminal are directly connected by the fuse (FUSE), detecting the voltage at the load's P+ terminal is equivalent to detecting the voltage at the battery's B+ terminal.

[0038] Figure 2 This is a schematic diagram of the MOS transistor switch state detection circuit provided in this embodiment.

[0039] like Figure 2 As shown, the MOSFET switch state detection circuit includes: a voltage divider module, an isolation module, an operational amplifier module, a microcontroller, a voltage reference point, and a voltage sampling point. The voltage sampling point collects the voltage at the B+ terminal of the battery. The voltage divider module is connected to the voltage sampling point and divides the voltage flowing into the sampling point. The isolation module is connected to the voltage divider module and isolates the output voltage of the voltage divider module. The operational amplifier module is connected to the isolation module and the voltage reference point, and compares the output voltage of the isolation module with the voltage flowing into the voltage reference point and outputs the result to the microcontroller. The microcontroller is connected to the MOSFET switch under test.

[0040] Specifically, in this embodiment, the voltage range of the battery B+ terminal of the battery management system is 30-60V. The voltage of the battery B+ terminal collected by the voltage sampling point must be divided before entering the microcontroller, then isolated by the isolation module, and then enter the operational amplifier module. In order to eliminate the interference of the operational amplifier, a VREF reference voltage is required for reference, so as to output a stable voltage value of about 1.5V to the microcontroller for ADC sampling.

[0041] Figure 3 This is a circuit diagram of the MOS transistor switch state detection circuit provided in this embodiment.

[0042] like Figure 3As shown, the voltage dividing module includes a voltage dividing resistor. The voltage dividing module is connected to the battery B+ terminal. The voltage dividing resistor includes one resistor or a plurality of resistors connected in series, wherein the voltage dividing resistor can take a resistor with a large resistance value to substantially divide the voltage of the battery B+ terminal.

[0043] Specifically, in the present embodiment, the voltage dividing module includes resistor R340, resistor R341, resistor R342, and resistor R336. One end of resistor R340, resistor R341, resistor R342, and resistor R336 connected in series is connected to the battery B+ terminal, and the other end is connected to the load P- terminal. Among them, resistor R340, resistor R341, and resistor R342 are resistors with a resistance value of 200K ohms and an accuracy of 1%, and resistor R336 is a resistor with a resistance value of 10K ohms and an accuracy of 1%. The 30-60V voltage of the battery B+ terminal of the battery management system is divided by resistor R340, resistor R341, resistor R342, and resistor R336, and the voltage sampled by the voltage sampling point is divided to about 0.16V, and then enters the isolation module.

[0044] As shown in Figure 3 The isolation module includes a power supply unit, an isolation capacitor, and an isolation diode; the isolation capacitor and the isolation diode are connected in parallel, and the power supply unit supplies power to the isolation capacitor and the isolation diode.

[0045] Specifically, the isolation capacitor is capacitor C135, and the isolation diode is diode D111. One end of the isolation capacitor and the isolation diode connected in parallel is connected to resistor R337, and the other end is connected to the load P- terminal. The other end of resistor R337 is connected between the electrical nodes of resistor R342 and resistor R336. Among them, resistor R337 is a resistor with a resistance value of 10K ohms and an accuracy of 5%.

[0046] The power supply unit is a system power supply, and the isolation module isolates the system power supply into the voltage required by the operational amplifier module. Specifically, since the circuit power supply unit of the isolation module needs to be powered separately, an independent power supply unit needs to be designed to power the isolation module to ensure system stability.

[0047] Figure 4 The circuit structure diagram of the power supply unit of the isolation module provided in the present embodiment.

[0048] The MOS tube switching state detection circuit provided in the present application has an isolation module and an operational amplifier module, so the system needs to be isolated to power the isolation module and the operational amplifier module. Specifically, as Figure 4As shown, the power supply of the system is VCC_5V, which is converted into +5V voltage by the power supply unit and output to the isolation module for power supply.

[0049] In the embodiment, the op-amp module comprises a reference voltage input end, a sampling voltage input end and an output end; the reference voltage input end is connected to the voltage reference point in the MOS switch state detection circuit; the sampling voltage input end is connected to the output end of the isolation module; and the output end outputs the op-amp result.

[0050] Specifically, as shown in the figure, Figure 3 The op-amp module comprises an op-amp U21, the No. 1 pin of the op-amp U21 is connected to the series connection node of the resistor R345 and the resistor R346, and the other end of the resistor R346 is connected to the reference voltage input end. The No. 2 pin of the op-amp U21 is connected to the ground GND. The No. 3 pin of the op-amp U21 is connected to the series connection node of the resistor R347 and the resistor R348. The No. 4 pin of the op-amp U21 is the output end. The No. 5 pin of the op-amp U21 is connected to the VCC_3V3 power supply voltage. The other end of the resistor R348 is connected to the No. 4 pin of the op-amp U21, i.e. the output end.

[0051] In the embodiment, the MOS switch state detection circuit further comprises a reference voltage module, which generates the reference voltage required by the op-amp module; and the output end of the reference voltage module is connected to the voltage reference point.

[0052] Figure 5 The circuit result schematic diagram of the reference voltage module provided in the embodiment is shown in the figure.

[0053] As shown in the figure, Figure 5 The one end of the reference voltage module is connected to the VCC_3V3 power supply voltage, and the reference voltage VREF is output after the processing of the reference voltage module. Specifically, as shown in the figure, Figure 5 In the reference voltage module, one end of the capacitor C138 is connected to the VCC_3V3 power supply voltage, and the other end is connected to the ground GND. One end of the resistor R343 is connected to the VCC_3V3 power supply voltage. The resistor R344 and the resistor R274 are connected in series, one end of which is connected to the other end of the resistor R343, and the other end of the series connection of the resistor R344 and the resistor R274 is connected to the ground GND. The gate of the triode is connected to the series connection node of the resistor R344 and the resistor R274, the source and the drain of the triode are respectively connected to the ground GND and the other end of the resistor R343. And the drain of the triode outputs the reference voltage VREF.

[0054] In this embodiment, in order for the operational amplifier module to accurately process and calculate the amplified signal, reduce distortion and fluctuations, and thus improve the stability of the circuit, the MOS transistor switch state detection circuit in this embodiment is designed with a reference voltage of approximately VREF = 1.24V.

[0055] like Figure 3 As shown, in this embodiment, terminal 1 of microcontroller U24 is connected to +5V voltage, terminals 2 and 3 of microcontroller U24 are connected to the output terminals of the isolation module, terminal 4 of microcontroller U24 is connected to the load P- terminal, terminal 5 of microcontroller U24 is grounded (GND), terminal 6 of microcontroller U24 is connected to the other end of resistor R347, terminal 7 of microcontroller U24 is connected to the other end of resistor R345, and terminal 8 of microcontroller U24 is connected to the VCC_3V3 power supply voltage.

[0056] In this embodiment, the MOS transistor switch state detection circuit further includes a voltage regulator module, which is connected to the operational amplifier module. The voltage regulator module regulates the operational amplifier output of the operational amplifier module and then outputs it to the microcontroller.

[0057] Specifically, such as Figure 3 As shown, in the voltage regulator module, one end of resistor R339 is connected to the output terminal of operational amplifier U21. Capacitor C140 and diode D112 are connected in parallel, with one end of the parallel connection between capacitor C140 and diode D112 connected to the other end of resistor R339. The other end of the parallel connection between capacitor C140 and diode D112 is grounded (GND). The end of the parallel connection between capacitor C140 and diode D112 and resistor R339 outputs the ADC sampling signal to the microcontroller.

[0058] In this embodiment, the output voltage of a battery ranges from 30-60V. Before entering the microcontroller, it must first be divided, then isolated by an isolation module, and finally pass through the operational amplifier and voltage regulator modules. To eliminate interference from the operational amplifier, a VREF reference voltage is required, resulting in a stable output voltage of approximately 1.5V that enters the microcontroller for ADC sampling. The microcontroller compares the sampled information with the information in its memory to ensure timely switching of the MOSFETs at the negative terminals of the battery and load. Since the isolation module circuit requires a separate power supply, an independent power supply module needs to be designed to power the isolation module to ensure system stability.

[0059] This embodiment also provides a battery management system, which includes a switch under test and a MOSFET switch state detection circuit. The MOSFET switch state detection circuit includes the MOSFET switch state detection circuit provided in any of the above embodiments, and the switch under test may include a switch connected to the negative terminal.

[0060] The embodiment also provides a battery system, which comprises a battery and a battery management system, the battery management system can comprise the battery management system provided by any one of the above embodiments, and a negative electrode of the battery can be connected with a to-be-tested switch in the battery management system.

[0061] The MOS tube switch state detection circuit provided by the application divides the battery voltage input by a voltage sampling point, then performs isolation through an isolation module, enters an amplification and voltage stabilization circuit, and finally compares the sampled information with the information stored in the memory through a single-chip microcomputer, so as to detect the on and off states of the to-be-tested MOS tube switch. The detection circuit provided by the application has a simple structure, is easy to implement, and has a relatively low cost.

[0062] Although the preferred embodiments of the utility model embodiments have been described, those skilled in the art can make further changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the utility model embodiments. Finally, it should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or terminal device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or terminal device comprising the element.

[0063] The MOS tube switch state detection circuit, battery management system and battery system provided by the embodiments of the application are described in detail above, and the principles and implementation manners of the application are described by applying specific examples in this document. The above embodiment descriptions are only used to help understand the technical solutions and core ideas of the application; those skilled in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement to some technical features; 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 application.

Claims

1. A MOS switch state detection circuit, characterized by, The MOS switch state detection circuit comprises a voltage sampling point, a voltage reference point, a voltage dividing module, an isolation module, an operational amplifier module, a single-chip microcomputer, and a voltage sampling point. The voltage dividing module is connected to the voltage sampling point and divides the voltage flowing into the voltage sampling point. The isolation module is connected to the voltage dividing module and isolates the output voltage of the voltage dividing module. The operational amplifier module is connected to the isolation module and the voltage reference point, compares the output voltage of the isolation module and the voltage flowing into the voltage reference point, and outputs to the single-chip microcomputer. The single-chip microcomputer is connected to the MOS switch to be detected. The voltage dividing module comprises a voltage dividing resistor.

2. The MOS switch state detection circuit of claim 1, wherein, The voltage dividing resistor comprises one resistor or a plurality of series-connected resistors.

3. The MOS switch state detection circuit of claim 2, wherein, The isolation module comprises a power supply unit, an isolation capacitor, and an isolation diode.

4. The MOS switch state detection circuit according to claim 1 or 2, characterized by, The isolation capacitor and the isolation diode are connected in parallel, and the power supply unit supplies power to the isolation capacitor and the isolation diode.

5. The MOS switch state detection circuit of claim 4, wherein, The power supply unit is a system power supply, and the isolation module isolates the system power supply into the voltage required by the operational amplifier module.

6. The MOS switch state detection circuit of claim 4, wherein, The operational amplifier module comprises a reference voltage input end, a sampling voltage input end, and an output end. The reference voltage input end is connected to the voltage reference point in the MOS switch state detection circuit. The sampling voltage input end is connected to the output end of the isolation module. The output end outputs the operational amplifier result.

7. The MOS switch state detection circuit of claim 6, wherein, The MOS switch state detection circuit further comprises a reference voltage module, which generates the reference voltage required by the operational amplifier module.

8. The MOS switch state detection circuit of claim 6, wherein, The output end of the reference voltage module is connected to the voltage reference point.

9. A battery management system, characterized by, The MOS switch state detection circuit further comprises a voltage stabilizing module, which is connected to the operational amplifier module.

10. A battery system characterized by, The voltage stabilizing module stabilizes the operational amplifier result output by the operational amplifier module and outputs to the single-chip microcomputer. The battery system comprises a battery and the battery management system according to claim 9. The battery system comprises a battery and the battery management system according to claim 9.

Images