High-voltage interlocking detection circuit, battery system and electric automobile

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By designing a high-voltage interlock detection circuit, the first voltage acquisition circuit, the second voltage acquisition circuit and the constant current circuit are used to monitor the voltage status of the high-voltage components in real time, solving the problem of lack of an effective detection mechanism in the prior art, and achieving rapid fault detection and operating status monitoring of the electric vehicle system.

CN119636415APending Publication Date: 2025-03-18SHANGHAI XUANYI NEW ENERGY DEV CO LTD

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Patent Information

Application Number: CN202411893356.2
Authority / Receiving Office: CN · China
Patent Type: Applications(China)
Current Assignee / Owner
Filing Date: 2024-12-20
Publication Date: 2025-03-18

AI Technical Summary

Technical Problem

The existing technology lacks an effective detection mechanism to promptly detect high-voltage plug-in failures, resulting in abnormal operation of electric vehicle systems.

Method used

A high-voltage interlock detection circuit is designed, including a first voltage acquisition circuit, a second voltage acquisition circuit and a constant current circuit. The microcontroller unit MCU is used to sample and detect the voltage status of the high-voltage components in real time, and to detect whether the connection status of the plug-in is normal.

Benefits of technology

Real-time monitoring of the operating status of high-voltage component system circuits is realized, and it can quickly detect system operation abnormalities caused by plug-in status abnormalities. The circuit is strong, the circuit is highly stable, the reliability is high, the detection method is simple, and the scope of application is wide.

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Abstract

The invention discloses a high-voltage interlocking detection circuit, a battery system and an electric vehicle. The high-voltage interlocking detection circuit comprises a first voltage acquisition circuit, a second voltage acquisition circuit and a constant current circuit, the input end of the first voltage acquisition circuit is connected to the input end of the high-voltage plug-in interface, the output end of the first voltage acquisition circuit is connected to a sampling interface of the MCU, and the first voltage acquisition circuit is used for detecting interlocking input voltage of high-voltage components; the input end of the second voltage acquisition circuit is connected to the output end of the high-voltage plug-in interface, the output end of the second voltage acquisition circuit is connected to the sampling interface of the MCU, and the second voltage acquisition circuit is used for detecting voltage output by interlocking of high-voltage components; the input end of the constant current circuit is externally connected with a power supply, and the output end is connected to the output end of the high-voltage plug-in interface for providing stable working current for the detection circuit; the invention discloses a high-voltage interlocking detection circuit, a battery system and an electric vehicle. System operation abnormity caused by abnormal states of high-voltage plug-ins is efficiently and quickly detected.

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Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a high-voltage interlock detection circuit, a battery system and an electric vehicle. Background Art

[0002] As electric vehicles rely on electricity to operate, the battery system (referring to the power supply of electric vehicles) is the core component of electric vehicles. There are many electronic unit modules integrated in the body of electric vehicles, and the high-voltage components are generally greater than 400V. Traditionally, there is no corresponding detection mechanism for high-voltage plug-ins, which makes it impossible to report high-voltage plug-ins in time when they fail, causing electric vehicle failures. Summary of the invention

[0003] Based on the technical problems existing in the background technology, the present invention proposes a high-voltage interlock detection circuit, a battery system and an electric vehicle, which can efficiently and quickly detect system operation abnormalities caused by abnormal high-voltage plug-in status.

[0004] A high-voltage interlock detection circuit, a battery system and an electric vehicle proposed in the present invention include a first voltage acquisition circuit, a second voltage acquisition circuit and a constant current circuit;

[0005] The input end of the first voltage acquisition circuit is connected to the input end of the high-voltage plug-in interface, and the output end is connected to the sampling interface of the microcontroller unit MCU, for detecting the voltage of the interlock input of the high-voltage component;

[0006] The input end of the second voltage acquisition circuit is connected to the output end of the high-voltage plug-in interface, and the output end is connected to the sampling interface of the microcontroller unit MCU, for detecting the voltage of the interlock output of the high-voltage component;

[0007] The input end of the constant current circuit is connected to an external power supply, and the output end is connected to the output end of the high-voltage plug-in interface, so as to provide a stable working current for the detection circuit.

[0008] Furthermore, the first voltage acquisition circuit includes a capacitor C4 and resistors R10, R11, and R12, one end of the resistor R11 and the resistor R12 connected in series is connected to the input end of the high-voltage plug-in interface, and the other end is grounded, one end of the resistor R10 is connected to the connection node of the resistor R11 and the resistor R12, and the other end is connected to the sampling interface of the micro control unit MCU, and one end of the capacitor C4 is connected to the sampling interface of the micro control unit MCU, and the other end is grounded.

[0009] Furthermore, the second voltage acquisition circuit includes a capacitor C2 and resistors R7, R8, and R9, one end of the resistor R7 and the resistor R9 connected in series is connected to the output end of the high-voltage plug-in interface, and the other end is grounded, one end of the resistor R8 is connected to the connection node of the resistor R7 and the resistor R9, and the other end is connected to the sampling interface of the micro control unit MCU, and one end of the capacitor C2 is connected to the sampling interface of the micro control unit MCU, and the other end is grounded.

[0010] Furthermore, the constant current circuit includes an operational amplifier U1A and a MOS tube T1, the positive input end of the operational amplifier U1A is connected to the output end of the high-voltage plug-in interface, the output end of the operational amplifier U1A is connected to the gate of the MOS tube T1, the drain of the MOS tube T1 is externally connected to a constant power supply, and the source is connected to the output end of the high-voltage plug-in interface.

[0011] Furthermore, the constant current circuit also includes resistors R3 and R5, the two ends of the resistor R3 are respectively connected to the output end of the operational amplifier U1A and the gate of the MOS tube T1, and the resistor R5 is respectively connected to the positive input end of the operational amplifier U1A and the output end of the high voltage plug-in interface.

[0012] Furthermore, the constant current circuit also includes a constant current adjustable resistance and capacitance module, which includes a capacitor C3 and resistors R6, R13, and R15; one end of the capacitor C3 is connected to the output end of the high-voltage plug-in interface and the other end is grounded, one end of the resistor R6 is connected to the output end of the high-voltage plug-in interface and the other end is connected to the resistor R5, and one end of the resistor R13 and the resistor R15 are connected in series and connected to the input end of the high-voltage plug-in interface and the other end is grounded.

[0013] Furthermore, the constant current circuit also includes an overcurrent protection module, which includes transistors Q1A and Q1B, the base of the transistor Q1A is connected to the collector of the transistor Q1B, the emitter of the transistor Q1A is connected to the input end of the high-voltage plug-in interface through a resistor R15, the collector of the transistor Q1A is grounded through a resistor R13, and the emitter of the transistor Q1B is grounded and the base is grounded through a resistor R13.

[0014] A battery system, characterized in that it comprises a high voltage socket, wherein the high voltage socket performs fault detection through the voltage interlock detection circuit as described above.

[0015] An electric vehicle comprises a battery system, wherein the battery system adopts the battery system described above.

[0016] The advantages of a high-voltage interlock detection circuit, a battery system and an electric vehicle provided by the present invention are: a high-voltage interlock detection circuit, a battery system and an electric vehicle provided in the structure of the present invention can monitor the operating status of the system circuit in the high-voltage component in real time, thereby effectively detecting the system operation abnormality caused by the abnormal plug-in status; at the same time, the constant current circuit realizes a stable current source output by configuring the resistor; the circuit has strong stability and high reliability; the detection method is simple in principle and has a wide range of applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 A flow chart for judging whether the high-voltage plug-in is connected normally;

[0019] Among them, 1-first voltage acquisition circuit, 2-second voltage acquisition circuit, 3-constant current circuit. DETAILED DESCRIPTION

[0020] Below, the technical solution of the present invention is described in detail through specific embodiments. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific implementation disclosed below.

[0021] like Figure 1 and 2 As shown, a high-voltage interlock detection circuit proposed by the present invention includes a first voltage acquisition circuit 1, a second voltage acquisition circuit 2 and a constant current circuit 3; the input end of the first voltage acquisition circuit 1 is connected to the input end of the high-voltage plug-in interface, and the output end is connected to the sampling interface of the micro control unit MCU, which is used to detect the voltage of the high-voltage component interlock input; the input end of the second voltage acquisition circuit 2 is connected to the output end of the high-voltage plug-in interface, and the output end is connected to the sampling interface of the micro control unit MCU, which is used to detect the voltage of the high-voltage component interlock output; the input end of the constant current circuit 3 is externally connected to the power supply, and the output end is connected to the output end of the high-voltage plug-in interface, which is used to provide a stable working current for the detection circuit.

[0022] This embodiment realizes the detection of interlock input voltage and interlock output voltage by setting a first voltage acquisition circuit 1 and a second voltage acquisition circuit 2; that is, by comparing the values of HVIL_OUT_ADC and HVIL_IN_ADC detected by the sampling interface of the microcontroller unit MCU, it can be determined whether the connection status of the high-voltage plug-in is normal.

[0023] At the same time, this embodiment monitors the operating status of the system circuit in the high-voltage component in real time, thereby effectively detecting system operation abnormalities caused by abnormal plug-in status. At the same time, the constant current circuit 3 realizes stable current source output through the configuration of resistors. The circuit has strong stability and high reliability. The detection method is simple in principle and has a wide range of applications.

[0024] In this embodiment, the first voltage acquisition circuit 1 includes a capacitor C4 and resistors R10, R11, and R12. One end of the resistor R11 and the resistor R12 connected in series is connected to the input end of the high-voltage plug-in interface, and the other end is grounded. One end of the resistor R10 is connected to the connection node of the resistor R11 and the resistor R12, and the other end is connected to the sampling interface of the micro control unit MCU. One end of the capacitor C4 is connected to the sampling interface of the micro control unit MCU, and the other end is grounded.

[0025] The second voltage acquisition circuit 2 includes a capacitor C2 and resistors R7, R8, and R9. One end of the resistor R7 and the resistor R9 connected in series is connected to the output end of the high-voltage plug-in interface, and the other end is grounded. One end of the resistor R8 is connected to the connection node of the resistor R7 and the resistor R9, and the other end is connected to the sampling interface of the micro control unit MCU. One end of the capacitor C2 is connected to the sampling interface of the micro control unit MCU, and the other end is grounded.

[0026] The first voltage acquisition circuit 1 collects the divided voltage on the resistor R12 as the basis for determining the working state of the HVIL_IN circuit; the resistor R10 and the capacitor C4 form a filter circuit, which complies with the Nyquist-Shannon sampling theorem, wherein the sampling frequency is significantly higher than twice the filter cutoff frequency, and the signal can be fully represented; the second voltage acquisition circuit 2 collects the divided voltage on the resistor R9 as the basis for determining the working state of the HVIL_OUT circuit; the resistor R8 and the capacitor C2 form a filter circuit, which complies with the Nyquist-Shannon sampling theorem, wherein the sampling frequency is significantly higher than twice the filter cutoff frequency, and the signal can be fully represented.

[0027] In this embodiment, the constant current circuit 3 includes an operational amplifier U1A and a MOS tube T1. The positive input terminal of the operational amplifier U1A is connected to the output terminal of the high-voltage plug-in interface through a resistor R5. The output terminal of the operational amplifier U1A is connected to the gate of the MOS tube T1 through a resistor R3. The drain of the MOS tube T1 is connected to an external constant power supply through a resistor R4, and the source is connected to the output terminal of the high-voltage plug-in interface.

[0028] In the specific implementation, operational amplifier U1A, R1, R2, C1, R3 and R5 are used to form a voltage follower, and the HVIL_PEN enable high level is 5V voltage, where resistor R3 is the current limiting resistor of the MOS tube gate drive, and the output voltage of operational amplifier U1A controls the on and off of MOS tube T1.

[0029] In addition, the constant current circuit 3 also includes a constant current adjustable resistance and capacitance module, which includes a capacitor C3 and resistors R6, R13, and R15; preferably, R6 is 750R, R13 is 40.2R, and R15 is 200R, and a constant 5mA current can be obtained through processing by the operational amplifier module; one end of the capacitor C3 is connected to the output end of the high-voltage plug-in interface and the other end is grounded, one end of the resistor R6 is connected to the output end of the high-voltage plug-in interface and the other end is connected to the resistor R5, and the resistor R13 and the resistor R15 are connected in series, and one end is connected to the input end of the high-voltage plug-in interface and the other end is grounded.

[0030] The constant current adjustable RC module makes the current in the HVIL_OUT and HVIL_IN loops approximately constant at 5mA; when the high-voltage plug-in is inserted normally, the connection status of the high-voltage plug-in can be determined safely and efficiently by comparing the values of HVIL_OUT_ADC and HVIL_IN_ADC.

[0031] Then, in order to effectively protect against the hazards caused by the short-circuit power supply, the constant current circuit 3 also includes an overcurrent protection module, which includes transistors Q1A and Q1B. The base of the transistor Q1A is connected to the collector of the transistor Q1B, and the emitter of the transistor Q1A is connected to the input end of the high-voltage plug-in interface through a resistor R15. The collector of the transistor Q1A is grounded through a resistor R13, and the emitter of the transistor Q1B is grounded and the base is grounded through a resistor R13.

[0032] The normal current in the R13, Q1A, R15 loop is 5mA. When the loop current becomes abnormally large, the voltage divider on resistor R13 increases. When it is greater than or equal to 0.6v, transistor Q1B is in a closed state and the base voltage of transistor Q1A is low, thereby shutting off transistor Q1A in time to protect the circuit.

[0033] like Figure 2 As shown, the process of judging whether the high-voltage plug-in is normally connected is as follows:

[0034] First, power on and initialize, HVIL_PEN and HVIL_NEN enable high level output;

[0035] Determine whether HVIL_OUT_ADC is greater than or equal to 0.9v and less than or equal to 0.95v;

[0036] If not, the external HVIL interlock loop is abnormal, the high voltage plug-in is disconnected, or the operational amplifier U1A fails;

[0037] If yes, continue to determine whether HVIL_IN_ADC is greater than or equal to 0.2v and less than or equal to 0.5v;

[0038] If not, the external HVIL interlock loop is abnormal, the high voltage plug-in is disconnected, or the operational amplifier U1A fails;

[0039] If yes, the external HVIL interlock loop is normal and the high voltage plug-in is connected normally.

[0040] When the high-voltage plug-in is inserted normally, the current direction in the first voltage acquisition circuit 1 passes through R11, R12 to GND, the current direction in the second voltage acquisition circuit 2 passes through R7, R9 to GND, and the constant current circuit 3 controls the loop current from KL30 through R4, T1, R6 to the HVIL_OUT terminal. When the external plug-in is connected, the current enters the HVIL_IN port and passes through R15, Q1A, R13 to GND.

[0041] Based on the above circuit relationship, this embodiment monitors the operating status of the system circuit in the high-voltage component in real time, thereby efficiently and quickly detecting system operating abnormalities caused by abnormal plug-in status.

[0042] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high voltage interlock detection circuit for detecting faults in high voltage components, characterized in that: It comprises a first voltage acquisition circuit (1), a second voltage acquisition circuit (2) and a constant current circuit (3); The input end of the first voltage acquisition circuit (1) is connected to the input end of the high-voltage plug-in interface, and the output end is connected to the sampling interface of the microcontroller unit MCU, and is used for detecting the voltage of the interlock input of the high-voltage component; The input end of the second voltage acquisition circuit (2) is connected to the output end of the high-voltage plug-in interface, and the output end is connected to the sampling interface of the microcontroller unit MCU, and is used for detecting the voltage of the interlock output of the high-voltage component; The input end of the constant current circuit (3) is externally connected to a power supply, and the output end is connected to the output end of the high-voltage plug-in interface, so as to provide a stable working current for the detection circuit.

2. The high voltage interlock detection circuit according to claim 1, characterized in that: The first voltage acquisition circuit (1) comprises a capacitor C4 and resistors R10, R11 and R12, wherein one end of the resistor R11 and the resistor R12 connected in series is connected to the input end of the high voltage plug-in interface and the other end is grounded, one end of the resistor R10 is connected to the connection node of the resistor R11 and the resistor R12 and the other end is connected to the sampling interface of the micro control unit MCU, and one end of the capacitor C4 is connected to the sampling interface of the micro control unit MCU and the other end is grounded.

3. The high voltage interlock detection circuit according to claim 1, characterized in that: The second voltage acquisition circuit (2) comprises a capacitor C2 and resistors R7, R8 and R9, wherein one end of the resistor R7 and the resistor R9 connected in series is connected to the output end of the high voltage plug-in interface and the other end is grounded, one end of the resistor R8 is connected to the connection node of the resistor R7 and the resistor R9 and the other end is connected to the sampling interface of the micro control unit MCU, and one end of the capacitor C2 is connected to the sampling interface of the micro control unit MCU and the other end is grounded.

4. The high voltage interlock detection circuit according to claim 1, characterized in that: The constant current circuit (3) comprises an operational amplifier U1A and a MOS tube T1, wherein the positive input end of the operational amplifier U1A is connected to the output end of the high-voltage plug-in interface, the output end of the operational amplifier U1A is connected to the gate of the MOS tube T1, the drain of the MOS tube T1 is externally connected to a constant power supply, and the source is connected to the output end of the high-voltage plug-in interface.

5. The high voltage interlock detection circuit according to claim 4, characterized in that: The constant current circuit (3) further comprises resistors R3 and R5, wherein the two ends of the resistor R3 are respectively connected to the output end of the operational amplifier U1A and the gate of the MOS tube T1, and the resistor R5 is respectively connected to the positive input end of the operational amplifier U1A and the output end of the high voltage plug-in interface.

6. The high voltage interlock detection circuit according to claim 5, characterized in that: The constant current circuit (3) also includes a constant current adjustable resistance and capacitance module, which includes a capacitor C3 and resistors R6, R13, and R15; one end of the capacitor C3 is connected to the output end of the high-voltage plug-in interface and the other end is grounded; one end of the resistor R6 is connected to the output end of the high-voltage plug-in interface and the other end is connected to the resistor R5; the resistor R13 and the resistor R15 are connected in series and one end is connected to the input end of the high-voltage plug-in interface and the other end is grounded.

7. The high voltage interlock detection circuit according to claim 6, characterized in that: The constant current circuit (3) also includes an overcurrent protection module, which includes transistors Q1A and Q1B, the base of the transistor Q1A is connected to the collector of the transistor Q1B, the emitter of the transistor Q1A is connected to the input end of the high-voltage plug-in interface through a resistor R15, the collector of the transistor Q1A is grounded through a resistor R13, and the emitter of the transistor Q1B is grounded and the base is grounded through the resistor R13.

8. A battery system, characterized in that: It comprises a high voltage socket, and the high voltage socket performs fault detection through the voltage interlock detection circuit according to any one of claims 1 to 7.

9. An electric vehicle, characterized in that: It comprises a battery system, wherein the battery system adopts the battery system according to claim 8.