High-voltage interlock diagnostic circuits, high-voltage interlock diagnostic methods, and electric vehicles

Abstract

This application provides a high-voltage interlock diagnostic circuit, a high-voltage interlock diagnostic method, and an electric vehicle. The high-voltage interlock diagnostic circuit includes a control module, a high-voltage interlock module, an output sampling module, an input sampling module, and a power supply module. The input and output terminals of the high-voltage interlock module are connected to an external circuit, forming a loop. The control module, the high-voltage interlock module, and the power supply module are connected in series to form the main circuit of the high-voltage interlock diagnostic circuit. The output sampling module and the input sampling module are respectively connected to the high-voltage interlock module to acquire the input and output voltages of the high-voltage interlock module. The control module can acquire the input and output voltages through the output and input sampling modules to diagnose the external circuit. The high-voltage interlock diagnostic circuit of this application improves the reliability and accuracy of the diagnostic results.

Description

Technical Field

[0001] This application relates to the field of electronics, and more particularly to a high-voltage interlock diagnostic circuit, a high-voltage interlock diagnostic method, and an electric vehicle. Background Technology

[0002] The high-voltage interlock loop function is mainly used to detect whether the high-voltage circuit of an electric vehicle is properly connected. The electric vehicle will only be powered on normally when the high-voltage circuit is detected to be properly connected.

[0003] In existing technology, electric vehicles can generate pulse-width modulation (PWM) signals through a control module. The electric vehicle can then determine the status of the high-voltage circuit by processing the output signals of two comparators in the module.

[0004] However, existing technologies do not perform fault diagnosis on the circuit itself, resulting in a high false detection rate. Summary of the Invention

[0005] This application provides a high-voltage interlock diagnostic circuit, a high-voltage interlock diagnostic method, and an electric vehicle to solve the problem that the prior art does not perform fault judgment on the state of the circuit itself, resulting in a high false detection rate.

[0006] In a first aspect, this application provides a high-voltage interlock diagnostic circuit, comprising:

[0007] Control module, high-voltage interlock module, output sampling module, input sampling module, and power supply module;

[0008] The input and output terminals of the high-voltage interlock module are connected to the external circuit. The first terminal of the high-voltage interlock module is connected to the output terminal of the power supply module, and the second terminal of the high-voltage interlock module is connected to the first input terminal of the control module.

[0009] The sampling terminal of the output sampling module is connected to the first terminal of the high-voltage interlock module, and the output terminal of the output sampling module is connected to the second input terminal of the control module; the sampling terminal of the input sampling module is connected to the input terminal of the high-voltage interlock module, and the output terminal of the input sampling module is connected to the second input terminal of the control module.

[0010] Optionally, the control module specifically includes: a microcontroller and an NMOS transistor;

[0011] The microcontroller's input terminal is connected to the output terminals of the input sampling module and the output sampling module; the microcontroller's input terminal is the second input terminal of the control module; the microcontroller's control terminal is connected to the gate of the NMOS transistor.

[0012] The drain of the NMOS transistor is connected to the second terminal of the high-voltage interlock module, and the drain of the NMOS transistor is the first input terminal of the control module; the source of the NMOS transistor is grounded.

[0013] Optionally, the high-voltage interlock module specifically includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor;

[0014] The first end of the first resistor is connected to the output end of the power module, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the first resistor is the output end of the high voltage interlock module.

[0015] The second end of the second resistor is connected to the first end of the third resistor, the first end of the fourth resistor, and the first end of the fifth resistor. The second end of the second resistor is the input end of the high-voltage interlock module.

[0016] The second terminals of the third and fourth resistors are grounded; the second terminal of the fifth resistor is connected to the first input terminal of the control module.

[0017] Optionally, the output sampling module specifically includes: a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor, and a first sampling unit;

[0018] The first end of the sixth resistor is connected to the first end of the high voltage interlock module. The first end of the sixth resistor is the sampling end of the output sampling module. The second end of the sixth resistor is connected to the first end of the seventh resistor. The second end of the sixth resistor is connected to the first end of the eighth resistor.

[0019] The second terminal of the seventh resistor is grounded; the second terminal of the eighth resistor is connected to the input terminal of the first sampling unit; the second terminal of the eighth resistor is connected to the first terminal of the first capacitor.

[0020] The output terminal of the first sampling unit is connected to the second input terminal of the control module, and the output terminal of the first sampling unit is the output terminal of the output sampling module; the second terminal of the first capacitor is grounded.

[0021] Optionally, the input sampling module specifically includes: a ninth resistor, a second capacitor, and a second sampling unit;

[0022] The first end of the ninth resistor is connected to the input end of the high voltage interlock module, the first end of the ninth resistor is the sampling end of the input sampling module, the second end of the ninth resistor is connected to the input end of the second sampling unit, and the second end of the ninth resistor is connected to the first end of the second capacitor.

[0023] The output terminal of the second sampling unit is connected to the second input terminal of the control module, and the output terminal of the second sampling unit is the output terminal of the input sampling module; the second terminal of the second capacitor is grounded.

[0024] Secondly, this application provides a high-voltage interlock diagnostic method, including:

[0025] The output voltage is obtained through the output sampling module, and the input voltage is obtained through the input sampling module.

[0026] Based on the output voltage and input voltage, diagnose whether there is a fault in the external circuit and / or the high-voltage interlock diagnostic circuit;

[0027] The diagnostic process ends when a fault occurs in the external circuit and / or the high-voltage interlock diagnostic circuit.

[0028] Optionally, based on the output voltage and input voltage, diagnose whether there is a fault in the external circuit and / or the high-voltage interlock diagnostic circuit, specifically including:

[0029] The microcontroller of the control module outputs a high-level signal, and when the NMOS transistor of the control module is turned on, the first input voltage is obtained through the input sampling module.

[0030] The microcontroller of the control module outputs a low-level signal, and when the NMOS transistor of the control module is turned off, the second input voltage is obtained through the input sampling module.

[0031] When the ratio of the first input voltage to the second input voltage is within the first preset range, the diagnostics determine that the external circuit and / or the high-voltage interlock diagnostic circuit are working normally.

[0032] When the ratio of the first input voltage and the second input voltage is not within the first preset range, the number of consecutive times the ratio of the first input voltage and the second input voltage is not within the first preset range is accumulated, and when the number of consecutive times reaches the preset number, the external circuit and / or the high-voltage interlock diagnostic circuit is diagnosed as having a fault.

[0033] Optionally, diagnosing whether a fault has occurred in the external circuit and / or the high-voltage interlock diagnostic circuit based on the output voltage and input voltage also includes:

[0034] When the input voltage and output voltage are within the preset voltage range, it is confirmed that the external circuit and / or high voltage interlock diagnostic circuit are working normally.

[0035] When the input voltage and / or output voltage values ​​are close to 0V or the power supply voltage of the power module, it is determined that there is a fault in the external circuit and / or the high-voltage interlock diagnostic circuit.

[0036] Optionally, diagnosing whether a fault has occurred in the external circuit and / or the high-voltage interlock diagnostic circuit based on the output voltage and input voltage also includes:

[0037] The calculated resistance value of the external circuit is obtained based on the output voltage, input voltage, and resistance value of the high-voltage interlock module.

[0038] When the difference between the theoretical resistance value and the calculated resistance value of the external circuit is not within the second preset range, it is determined that the external circuit has malfunctioned.

[0039] Thirdly, an electric vehicle is provided with an external circuit and a high-voltage interlock diagnostic circuit in the first aspect and any possible design of the first aspect, wherein the external circuit is connected to the high-voltage interlock diagnostic circuit.

[0040] The high-voltage interlock diagnostic circuit, high-voltage interlock diagnostic method, and electric vehicle provided in this application include a control module, a high-voltage interlock module, an output sampling module, an input sampling module, and a power supply module. The input and output terminals of the high-voltage interlock module are connected to an external circuit, forming a loop. When the state of the external circuit changes, the loop formed by the high-voltage interlock module and the external circuit also changes. The first terminal of the high-voltage interlock module is connected to the output terminal of the power supply module. The second terminal of the high-voltage interlock module is connected to the first input terminal of the control module. The control module, high-voltage interlock module, and power supply module form the main circuit of the high-voltage interlock diagnostic circuit. The output sampling module and input sampling module in the high-voltage interlock diagnostic circuit are respectively connected to the first terminal and output terminal of the high-voltage interlock module to obtain the input voltage and output voltage of the high-voltage interlock module. The output sampling module and input sampling module can send the input voltage and output voltage to the control module, enabling the control module to diagnose the external circuit based on the input voltage and output voltage, thereby improving the reliability and accuracy of the diagnostic results. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the structure of a high-voltage interlock diagnostic circuit provided in one embodiment of this application;

[0043] Figure 2 This is a schematic diagram of the structure of a high-voltage interlock diagnostic circuit provided in one embodiment of this application;

[0044] Figure 3 A flowchart illustrating a high-voltage interlock diagnostic method provided in one embodiment of this application;

[0045] Figure 4 A flowchart illustrating a high-voltage interlock diagnostic method provided in one embodiment of this application;

[0046] Figure 5 A flowchart illustrating a high-voltage interlock diagnostic method provided in one embodiment of this application;

[0047] Figure 6 This is a schematic diagram of the structure of an output electron provided in an embodiment of this application;

[0048] Figure 7 This is a schematic diagram of the hardware structure of a microcontroller provided in an embodiment of this application. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate. For example, without departing from the scope of this document, first information can also be referred to as second information, and similarly, second information can also be referred to as first information.

[0051] Depending on the context, the word "if" as used here can be interpreted as "when," "when," or "in response to determination."

[0052] Furthermore, as used herein, the singular forms “a,” “one,” and “the” are intended to also include the plural forms, unless the context indicates otherwise.

[0053] It should be further understood that the terms “comprising” or “including” indicate the presence of features, steps, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups.

[0054] The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Therefore, “A, B, or C” or “A, B, and / or C” means “any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C”. Exceptions to this definition occur only when combinations of elements, functions, steps, or operations are inherently mutually exclusive in some way.

[0055] High Voltage Interlock (HII) is a crucial protection function in electrical circuits. Its primary function is to detect the connection status of high-voltage connectors in the high-voltage circuit of an electric vehicle (EV) and identify whether the connectors are properly connected. If an abnormality is detected in the high-voltage circuit connection, the system cannot power on. The EV will only power on and operate normally when the high-voltage circuit connection is detected as normal, thus ensuring vehicle and passenger safety. In existing technologies, EVs can determine the high-voltage circuit status using a combination of hardware and software. The control module in the EV can generate two pulse-width modulation (PWM) signals. The EV can then compare the PWM signal values ​​output from the two comparators using a processing module to determine the high-voltage circuit status. However, this method does not address whether the circuit itself is faulty. When detecting the circuit status, this method is prone to errors due to circuit faults, leading to wasted time for maintenance personnel. Furthermore, these errors may prevent the vehicle from entering the corresponding stage, affecting its normal operation. Additionally, the detection process requires generating PWM signals using a control model and comparing them with the processing module, which is prone to significant errors and delays, resulting in low detection accuracy. Alternatively, in existing technologies, electric vehicles can also detect faults in the voltage interlock circuit by controlling the frequency and duty cycle of the PWM signal in the switching circuit and setting the software PM rising edge acquisition point and the software ADC acquisition point to be connected to the first and second acquisition circuits. However, the circuit itself is affected by various conditions, and its state is not stable. This method does not perform multiple tests on the circuit, and there is no confirmation stage when a fault occurs, resulting in low detection accuracy.

[0056] To address the aforementioned problems, this application proposes a high-voltage interlock diagnostic circuit. This application achieves fault detection by the circuit itself through a combination of hardware design and software programming. It can also detect the loop status of the high-voltage interlock diagnostic circuit even when the external circuit is fault-free. This detection eliminates interlock status detection errors caused by faults in the high-voltage interlock diagnostic circuit itself. In the software strategy, this application can perform multiple tests even when a fault is detected in the high-voltage interlock diagnostic circuit itself, thereby reducing the possibility of false detections and improving the reliability and accuracy of the diagnosis. Furthermore, this application does not require the use of a PWM signal, thus eliminating the possibility of errors and further improving detection reliability. In addition, this application can calculate the loop resistance value of the external circuit, thereby more accurately determining the status of the external circuit. This application does not rely on a PWM signal, reducing the overall complexity of the high-voltage interlock diagnostic circuit, and further simplifies the high-voltage interlock diagnostic circuit by detecting circuit fault status through a software strategy, thus reducing costs.

[0057] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0058] Figure 1 A schematic diagram of a high-voltage interlock diagnostic circuit according to an embodiment of this application is shown. The high-voltage interlock diagnostic circuit 10 of this embodiment may include: a control module 11, a high-voltage interlock module 12, an output sampling module 13, an input sampling module 14, and a power supply module 15.

[0059] In this embodiment, as Figure 1 As shown, the high-voltage interlock module 12 may include an input terminal and an output terminal. The input and output terminals of the high-voltage interlock module 12 can be connected to an external circuit to form a loop. The high-voltage interlock module 12 can be combined with external circuits in different states to form different loops. The high-voltage interlock module 12 itself consists of a resistor loop. The high-voltage interlock module 12 may also include two ports: a first terminal and a second terminal. The first terminal of the high-voltage interlock module 12 is connected to the output terminal of the power supply module 15. The second terminal of the high-voltage interlock module 12 is connected to the first input terminal of the control module 11. The power supply module 15, the high-voltage interlock module 12, and the control module 11 constitute a high-voltage interlock diagnostic circuit. The power supply module 15 can provide a constant current signal to the high-voltage interlock module 12.

[0060] In one example, the resistor circuit of the high-voltage interlock module 12 can be as follows: Figure 2As shown, the system specifically includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The first terminal of the first resistor R1 is connected to the output terminal of the power module 15. The second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2. The second terminal of the second resistor R2 is connected to the first terminals of the third resistor R3, the fourth resistor R4, and the fifth resistor R5. The second terminals of the third resistor R3 and the fourth resistor R4 are grounded. The second terminal of the fifth resistor R5 is connected to the first input terminal of the control module 11. The output terminal of the high-voltage interlock module 12 is the second terminal of the first resistor R1. The input terminal of the high-voltage interlock module 12 is the second terminal of the second resistor R2. The first terminal of the high-voltage interlock module 12 is the first terminal of the first resistor R1. The second terminal of the high-voltage interlock module 12 is the second terminal of the fifth resistor R5. When the fifth resistor R5 is grounded through the control module 11, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 form a parallel circuit. Otherwise, when the control module 11 connected to the fifth resistor R5 is turned off, the third resistor R3 and the fourth resistor R4 form a parallel circuit.

[0061] In one example, the control module 11 can be as follows: Figure 2 As shown, the control module 11 specifically includes a microcontroller 112 and an NMOS transistor Q1. The control terminal of the microcontroller 112 is connected to the gate (G) of the NMOS transistor Q1. Since the transistor in this control module 11 is an NMOS transistor Q1, when the microcontroller 112 outputs a high-level signal, the NMOS transistor Q1 is turned on. When the microcontroller 112 outputs a low-level signal, the NMOS transistor is turned off. The drain (D) of the NMOS transistor Q1 is the first input terminal of the control module 11. The drain (D) of the NMOS transistor Q1 is connected to the second terminal of the high-voltage interlock module 12. The second terminal of the high-voltage interlock module 12 is the second terminal of the fifth resistor R5. Therefore, the drain (D) of the NMOS transistor Q1 is connected to the second terminal of the fifth resistor R5. The source (S) of the NMOS transistor Q1 is grounded. Therefore, when the microcontroller 112 outputs a high-level signal, the fifth resistor R5 is grounded. When the microcontroller 112 outputs a low-level signal, the circuit containing the fifth resistor R5 is turned off. The input terminal of the microcontroller 112 in the control module 11 is connected to the output terminal of the input sampling module 14 to acquire the input voltage. The input terminal of the microcontroller 112 is also connected to the output terminal of the output sampling module 13 to acquire the output voltage. The input terminal of the microcontroller 112 is the second input terminal of the control module 11. The microcontroller 112 controls the NMOS transistor Q1 by controlling the high and low levels of the control terminal, enabling software to control the NMOS transistor's on / off state through control strategies, thus facilitating software diagnostics. The microcontroller 112 in the control module 11 can also perform diagnostic calculations for external circuits based on the acquired input and output voltages.

[0062] In this embodiment, the high-voltage interlock diagnostic circuit may further include an output sampling module 13 and an input sampling module 14. The sampling terminal of the output sampling module 13 is connected to the first terminal of the high-voltage interlock module 12, and is used to collect the output voltage of the high-voltage interlock module 12. The output terminal of the output sampling module 13 is connected to the second input terminal of the control module 11, and is used to send the collected output voltage of the high-voltage interlock module 12 to the control module 11. The sampling terminal of the input sampling module 14 is connected to the input terminal of the high-voltage interlock module 12, and is used to collect the input voltage of the high-voltage interlock module 12. The output terminal of the input sampling module 14 is connected to the second input terminal of the control module 11, and is used to send the collected input voltage of the high-voltage interlock module 12 to the control module 11. The output sampling module 13 and the input sampling module 14 can collect different input and output voltages when external circuits in different states form different loops with the high-voltage interlock module 12. The controller can perform diagnostics on the external circuit based on these input and output voltages. The controller can also perform diagnostics on the high-voltage interlock diagnostic circuit itself based on the input and output voltages. Both the input sampling module 14 and the output sampling module 13 can be analog-to-digital converter (ADC) sampling modules.

[0063] In one example, the output sampling module 13 can be as follows: Figure 2 As shown, the system specifically includes: a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first capacitor C1, and a first sampling unit 131. The first terminal of the sixth resistor R6 is connected to the first terminal of the high-voltage interlock module 12. The second terminal of the sixth resistor R6 is connected to the first terminal of the seventh resistor R7. The second terminal of the sixth resistor R6 is connected to the first terminal of the eighth resistor R8. The second terminal of the seventh resistor R7 is grounded. The sixth resistor R6 and the seventh resistor R7 form a voltage divider circuit to divide the output voltage of the power module 15, ensuring that the output voltage obtained by the control module 11 is within a safe range. The voltage between the sixth resistor R6 and the seventh resistor R7 can be expressed as V. outThe second end of the eighth resistor R8 is connected to the input terminal of the first sampling unit 131. The second end of the eighth resistor R8 is connected to the first end of the first capacitor C1. The second end of the first capacitor C1 is grounded. The eighth resistor R8 and the first capacitor C1 form a filter circuit to achieve filtering and ensure signal stability. The output terminal of the first sampling unit 131 is connected to the second input terminal of the control module 11. The first sampling unit 131 can be a voltage measuring device or other equipment. The first sampling unit 131 is used to measure the output voltage of the output sampling module 13. The first sampling unit 131 can be connected to the unit machine in the control module 11 via a data line. Alternatively, the first sampling unit 131 can also be connected to the unit machine in the control module 11 via a wireless network, Bluetooth, infrared, or other near-field communication networks. The first end of the sixth resistor R6 is the sampling terminal of the output sampling module 13. The output terminal of the first sampling unit 131 is the output terminal of the output sampling module 13.

[0064] In one example, the input sampling module 14 can be as follows: Figure 2 As shown, the system specifically includes: a ninth resistor R9, a second capacitor C2, and a second sampling unit 141. The first end of the ninth resistor R9 is connected to the input terminal of the high-voltage interlock module 12. The second end of the ninth resistor R9 is connected to the input terminal of the second sampling unit 141. The second end of the ninth resistor R9 is connected to the first end of the second capacitor C2. The second end of the second capacitor C2 is grounded. The ninth resistor R9 and the second capacitor C2 form a filter circuit to achieve filtering and ensure signal stability. The output terminal of the second sampling unit 141 is connected to the second input terminal of the control module 11. The output terminal of the second sampling unit 141 is the output terminal of the input sampling module 14. The second sampling unit 141 can be connected to the unit machine in the control module 11 via a data cable. Alternatively, the second sampling unit 141 can also be connected to the unit machine in the control module 11 via a wireless network, Bluetooth, infrared, or other near-field communication networks. The first end of the ninth resistor R9 is the sampling terminal of the input sampling module 14. The output terminal of the second sampling unit 141 is the output terminal of the input sampling module 14. The input voltage at the input terminal of the input sampling module 14 can be expressed as V. in

[0065] In one example, the power module 15 can be as follows: Figure 2 The diagram may include a constant current source. The first terminal of this constant current source is connected to VCC. The second terminal is connected to the first terminal of the high-voltage interlock module 12. The output current of this constant current source is represented by I, and the output voltage is represented by V. A express.

[0066] In this embodiment, the combination of the control module 11, the high-voltage interlock module 12, the output sampling module 13, the input sampling module 14, and the power supply module 15 enables the diagnostic function of the high-voltage interlock diagnostic circuit. This high-voltage interlock diagnostic circuit can be diagnosed via software, enabling the diagnosis of both the external circuit and the high-voltage interlock circuit.

[0067] The high-voltage interlock diagnostic circuit provided in this application includes a control module, a high-voltage interlock module, an output sampling module, an input sampling module, and a power supply module. The input and output terminals of the high-voltage interlock module are connected to an external circuit, forming a loop. When the state of the external circuit changes, the loop formed by the high-voltage interlock module and the external circuit also changes. The first terminal of the high-voltage interlock module is connected to the output terminal of the power supply module. The second terminal of the high-voltage interlock module is connected to the first input terminal of the control module. The control module, the high-voltage interlock module, and the power supply module form the main circuit of the high-voltage interlock diagnostic circuit. The output sampling module and the input sampling module in this high-voltage interlock diagnostic circuit are respectively connected to the first terminal and the output terminal of the high-voltage interlock module to acquire the input voltage and output voltage of the high-voltage interlock module. The output sampling module and the input sampling module can send the input voltage and the output voltage to the control module, so that the control module can diagnose the external circuit based on the input voltage and the output voltage. In this application, by using this high-voltage interlock diagnostic circuit, both the external circuit and the high-voltage interlock diagnostic circuit can be tested, improving the reliability and accuracy of the diagnostic results.

[0068] Figure 3 A flowchart illustrating a high-voltage interlock diagnostic method according to an embodiment of this application is shown. Figure 1 and Figure 2 Based on the embodiments, such as Figure 3 As shown, taking the control module in the high-voltage interlock diagnostic circuit as the execution subject, the method in this embodiment may specifically include the following steps:

[0069] S101. Obtain the output voltage through the output sampling module and the input voltage through the input sampling module.

[0070] In this embodiment, the external circuit and the high-voltage interlock module in the high-voltage interlock diagnostic circuit form a loop. An input sampling module located at the input terminal of the high-voltage interlock module can acquire the input voltage from the external circuit to the high-voltage interlock module. This input voltage can be expressed as V. in The output sampling module located at the first terminal of this high-voltage interlock module can acquire the output voltage of the power supply voltage output by the power module passing through the output terminal of the high-voltage interlock module. This output voltage can be expressed as V. out .

[0071] S102. Based on the output voltage and input voltage, diagnose whether there is a fault in the external circuit and / or the high-voltage interlock diagnostic circuit.

[0072] In this embodiment, the microcontroller in the control module can obtain the input voltage and output voltage from the input sampling module and the output sampling module. The microcontroller in the control module can then make judgments based on these input and output voltages to diagnose the external circuit and / or the high-voltage interlock diagnostic circuit. This diagnosis is used to determine whether the external circuit and / or the high-voltage interlock diagnostic circuit has malfunctioned.

[0073] In one example, the diagnostic process may specifically include multiple diagnostic items. These diagnostic items may be as follows: Figure 4 As shown. The specific steps are as follows:

[0074] S20. Through software diagnostics, determine whether there is any abnormality in the external circuit and / or the high-voltage interlock diagnostic circuit. The specific diagnostic process for this step can be as follows: Figure 5 As shown, it includes:

[0075] S201. The microcontroller of the control module outputs a high-level signal, and when the NMOS transistor of the control module is turned on, the first input voltage is obtained through the input sampling module.

[0076] In this embodiment, the microcontroller of the control module can output a high-level signal. This high-level signal will control the NMOS transistor in the control module to turn on. When the NMOS transistor is turned on, the fifth resistor in the high-voltage interlock module is grounded. At this time, the third, fourth, and fifth resistors in the high-voltage interlock module are connected in parallel. The parallel third, fourth, and fifth resistors can be regarded as a combined resistor R. A The input sampling module can acquire the first output voltage. This first output voltage can be represented as V1.

[0077] S202. The microcontroller of the control module outputs a low-level signal, and when the NMOS transistor of the control module is turned off, the second input voltage is obtained through the input sampling module.

[0078] In this embodiment, the microcontroller of the control module can output a low-level signal. This low-level signal will control the NMOS transistor in the control module to turn off. When the NMOS transistor is turned off, the circuit containing the fifth resistor in the high-voltage interlock module is cut off and cannot conduct. At this time, the third and fourth resistors in the high-voltage interlock module are connected in parallel. The parallel third and fourth resistors can be regarded as a combined resistor R. B The input sampling module can acquire the second output voltage. This second output voltage can be represented as V2.

[0079] S203. When the ratio of the first input voltage to the second input voltage is within the first preset range, the external circuit and / or the high-voltage interlock diagnostic circuit are confirmed to be working normally.

[0080] In this embodiment, the microcontroller of the control module can calculate the ratio of the first input voltage V1 to the second input voltage V2 after acquiring the first input voltage V1 and the second input voltage V2. The first input voltage V1 and the second input voltage V2 are the combined resistance R. A With combined resistor R B The ratio of V2 to V1. This ratio can be expressed as V2 / V1. The microcontroller of the control module can determine the range of this ratio V2 / V1. When the ratio V2 / V1 is within the first preset range, the microcontroller can determine that the external circuit and / or the high-voltage interlock diagnostic circuit is working normally. The theoretical value of this first preset range is [-0.3, +0.3].

[0081] S204. When the ratio of the first input voltage and the second input voltage is not within the first preset range, the number of consecutive times the ratio of the first input voltage and the second input voltage is not within the first preset range is accumulated, and when the number of consecutive times reaches the preset number, the external circuit and / or the high-voltage interlock diagnostic circuit is diagnosed as having a fault.

[0082] In this embodiment, the microcontroller of the control module can accumulate the number of consecutive times that the ratio V2 / V1 is not within the first preset range when it determines that the ratio V2 / V1 is not within the first preset range. When the number of consecutive times is less than the preset number, the microcontroller of the control module can return to step S201, obtain the first input voltage V1 and the second input voltage V2 at the next moment, and calculate the ratio V2 / V1. When the ratio V2 / V1 at the next moment is still not within the first preset range, the microcontroller of the control module continues to accumulate the number of consecutive times that the ratio V2 / V1 is not within the first preset range. For example, when the microcontroller of the control module determines that the ratio V2 / V1 is not within the first preset range at the first moment, the accumulated number of consecutive times is 1. The microcontroller of the control module can continue to obtain the first input voltage V1 and the second input voltage V2 at the second moment and calculate the ratio V2 / V1. When the ratio V2 / V1 at the second moment is still not within the first preset range, the microcontroller of the control module can accumulate the number of consecutive times to 2. The microcontroller of the control module can continue to acquire the first input voltage V1 and the second input voltage V2 at the third moment and calculate the ratio V2 / V1. When the ratio V2 / V1 at the third moment is still not within the first preset range, the microcontroller of the control module can accumulate the calculation to 3 consecutive times. This continues until the consecutive count reaches the preset number. When the consecutive count reaches the preset number, the microcontroller of the control module can determine that a fault has occurred in the external circuit and / or the high-voltage interlock diagnostic circuit. The preset number can be determined based on empirical values. For example, the preset number can be 3 times, 5 times, 10 times, etc. The first moment, the second moment, and the third moment are consecutive moments. Usually, based on the sampling efficiency of the first input voltage V1 and the second input voltage V2, the time interval between the first moment, the second moment, and the third moment can be 1ms.

[0083] It is important to note that during the cumulative calculation of consecutive counts, if the ratio V2 / V1 falls within the first preset range at any given moment, step S203 will be executed at that moment to confirm that the external circuit and / or high-voltage interlock diagnostic circuit is functioning normally, and the diagnostic session will end. For example, after the cumulative count reaches 2, the microcontroller of the control module acquires the first input voltage V1 and the second input voltage V2 at the third moment and calculates the ratio V2 / V1. If the ratio V2 / V1 at the third moment falls within the first preset range, the microcontroller will execute step S203 at that third moment and end the diagnostic session, instead of continuing with step S204.

[0084] S30. When the input voltage and output voltage are within the preset voltage range, confirm that the external circuit and / or high-voltage interlock diagnostic circuit are working normally.

[0085] In one example, the preset voltage range can be all normal voltage values. That is, when an input voltage and an output voltage are detected, the microcontroller of the control module can determine that the external circuit and / or the high-voltage interlock diagnostic circuit is working normally. Here, 0xFFFF (error value) and 0xFFFE (initial value) can be abnormal values. That is, when the input voltage or output voltage is 0xFFFF or 0xFFFE, the microcontroller of the control module can determine that there is an abnormality in the external circuit and / or the high-voltage interlock diagnostic circuit.

[0086] In another example, the preset voltage range can be a range determined based on empirical values. When both the input voltage and the output voltage are within this preset range, the external circuit and / or the high-voltage interlock diagnostic circuit are in normal operating condition. This normal operating condition can include the two circuits being either on or off. The preset voltage range can be [0V, 10V]. That is, when the input voltage or output voltage value is within the range of 0V to 10V, the input voltage or output voltage is normal. When both the input voltage and output voltage are normal, the external circuit and / or the high-voltage interlock diagnostic circuit are operating normally.

[0087] In one example, when the output voltage cannot be detected, or the output voltage value is not within the preset voltage range, the microcontroller of the control module can directly determine that there is a problem with the constant current source of the power supply module.

[0088] S40. When the input voltage and / or output voltage value is close to 0V or the power supply voltage of the power module, a fault is determined in the external circuit and / or the high-voltage interlock diagnostic circuit. When the input voltage or output voltage value is close to 0V, the external circuit and / or the high-voltage interlock diagnostic circuit is in a short-ground state. This short-ground state is equivalent to a ground short circuit. When either the input voltage or the output voltage is close to the power supply voltage, the external circuit and / or the high-voltage interlock diagnostic circuit is in a power-off state. This power-off state is equivalent to a power-on short circuit. When the external circuit and / or the high-voltage interlock diagnostic circuit is in a short-ground state or a power-off state, a fault is determined in the external circuit and / or the high-voltage interlock diagnostic circuit.

[0089] S50. By calculating the current value, the current value is diagnosed, and it is determined whether there is an abnormality in the external circuit and / or the high-voltage interlock diagnostic circuit. The specific process of this step includes:

[0090] S501. When the external circuit and / or the high-voltage interlock diagnostic circuit are in normal working condition, the microcontroller of this control module can use the input current, output current, and the resistance value in the high-voltage interlock diagnostic circuit to calculate the current value A. This current value A will be used to determine whether the external circuit and / or the high-voltage interlock diagnostic circuit is in a conducting state or a disconnected state.

[0091] S502. The microcontroller of this control module can compare the current value A with a current threshold. When the current value A is greater than or equal to the current threshold, it can be determined that the external circuit and / or the high-voltage interlock diagnostic circuit is in a conducting state. Otherwise, when the current value A is less than or equal to the current threshold, it can be determined that the external circuit and / or the high-voltage interlock diagnostic circuit is in a disconnected state. The current threshold can be determined based on empirical values. For example, the current threshold can be 0.3A, 1A, 5A, etc.

[0092] S60. By calculating the resistance value, the resistance value is diagnosed, and it is determined whether there is an abnormality in the external circuit and / or the high-voltage interlock diagnostic circuit. The specific process of this step includes:

[0093] S601. Calculate the calculated resistance value of the external circuit based on the output voltage, input voltage, and resistance value of the high-voltage interlock module.

[0094] In this embodiment, based on the high-voltage interlock diagnostic circuit, the following can be summarized: Figure 6 The circuit diagram shown is illustrated. The power supply module may include Vcc and a constant current source. The circuit also includes a first resistor R1, a second resistor R2, and a combined resistor R... A This constitutes a high-voltage interlock module. Among them, the combined resistor R... A It consists of a third resistor, a fourth resistor, and a fifth resistor connected in parallel. R out This represents the resistance value of the external circuit.

[0095] according to Figure 6 The circuit shown can be used to derive the following equations:

[0096]

[0097] Because in this formula, the input voltage V in Output voltage V out The first resistor R1, the second resistor R2, and the combined resistor R A All variables are known. Therefore, the microcontroller in the control module can calculate the only unknown variable, R. out .

[0098] S602. When the difference between the theoretical resistance value and the calculated resistance value of the external circuit is not within the second preset range, it is determined that the external circuit has malfunctioned.

[0099] In this embodiment, the microcontroller of the control module can obtain the theoretical resistance value of the external circuit and compare it with the calculated resistance value. When the difference between the theoretical resistance value and the calculated resistance value is within a second preset range, it indicates that the difference is within the normal range. This second preset range can be a range determined based on empirical values. For example, the second preset range can be [-0.1, 0.1]. Otherwise, when the difference between the theoretical resistance value and the calculated resistance value is not within the second preset range, it indicates that the difference is too large, meaning that the external circuit has malfunctioned.

[0100] S103. When a fault occurs in the external circuit and / or the high-voltage interlock diagnostic circuit, the current diagnostic process ends.

[0101] In this embodiment, the microcontroller of the control module can terminate the current diagnosis and report the diagnosis result when it determines that the external circuit and / or the high-voltage interlock diagnostic circuit is faulty. Otherwise, when the microcontroller of the control module determines that the external circuit and / or the high-voltage interlock diagnostic circuit is working normally, the microcontroller of the control module can periodically execute the above-mentioned abnormal diagnosis process.

[0102] In one example, the microcontroller of the control module can set a flag bit at a corresponding location when determining the status of the external circuit and / or the high-voltage interlock diagnostic circuit. This flag bit is used to identify the status of the external circuit and / or the high-voltage interlock diagnostic circuit.

[0103] In one implementation, the state can include both normal operation and failure.

[0104] In another implementation, the state may include at least one of short ground, power outage, on, and off.

[0105] The high-voltage interlock diagnostic circuit provided in this application includes an input sampling module located at the input terminal of the high-voltage interlock module, which can acquire the input voltage from the external circuit. An output sampling module located at the first terminal of the high-voltage interlock module can acquire the output voltage of the power supply voltage output from the power module after passing through the output terminal of the high-voltage interlock module. The microcontroller in the control module can make judgments based on the input and output voltages to diagnose the external circuit and / or the high-voltage interlock diagnostic circuit. This diagnosis is used to determine whether the external circuit and / or the high-voltage interlock diagnostic circuit has a fault. When the microcontroller in the control module determines that the external circuit and / or the high-voltage interlock diagnostic circuit has a fault, it can end the current diagnosis and report the diagnosis result. In this application, the software diagnosis of the external circuit and the high-voltage interlock circuit is achieved through the analysis of the input and output voltages by the microcontroller in the control module, improving the diagnostic accuracy.

[0106] Figure 7This diagram illustrates a hardware structure of a microcontroller according to an embodiment of this application. Figure 7 As shown, the microcontroller 20 is used to implement the operation corresponding to the microcontroller in any of the above method embodiments. The microcontroller 20 in this embodiment may include: a memory 21, a processor 22, and a communication interface 24.

[0107] The memory 21 is used to store computer programs. The memory 21 may include high-speed random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device, and may also be a USB flash drive, external hard drive, read-only memory, disk or optical disc, etc.

[0108] Processor 22 is used to execute the computer program stored in the memory to implement the high-voltage interlock diagnosis method in the above embodiments. For details, please refer to the relevant descriptions in the foregoing method embodiments. The processor 22 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by the hardware processor, or implemented by a combination of hardware and software modules in the processor.

[0109] Alternatively, the memory 21 can be either standalone or integrated with the processor 22.

[0110] When the memory 21 is a device independent of the processor 22, the microcontroller 20 may also include a bus 23. This bus 23 is used to connect the memory 21 and the processor 22. The bus 23 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0111] The communication interface 24 is used to communicate with the acquisition units in the input sampling module and the output sampling module to obtain the measured input voltage and output voltage.

[0112] The microcontroller provided in this embodiment can be used to execute the above-mentioned high-voltage interlock diagnostic method. Its implementation method and technical effect are similar, and will not be described again in this embodiment.

[0113] This application also provides an electric vehicle, characterized in that the electric vehicle is equipped with an external circuit and such as Figure 2 or Figure 3 The high-voltage interlock diagnostic circuit shown is connected to the external circuit.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A high-voltage interlock diagnostic circuit, characterized in that, The circuit includes: a control module, a high-voltage interlock module, an output sampling module, an input sampling module, and a power supply module; The input and output terminals of the high-voltage interlock module are connected to an external circuit. The first terminal of the high-voltage interlock module is connected to the output terminal of the power supply module, and the second terminal of the high-voltage interlock module is connected to the first input terminal of the control module. The sampling terminal of the output sampling module is connected to the first terminal of the high-voltage interlock module, and the output terminal of the output sampling module is connected to the second input terminal of the control module; the sampling terminal of the input sampling module is connected to the input terminal of the high-voltage interlock module, and the output terminal of the input sampling module is connected to the second input terminal of the control module. The control module specifically includes: a microcontroller and an NMOS transistor; The input terminal of the microcontroller is connected to the output terminal of the input sampling module and the output terminal of the output sampling module; the input terminal of the microcontroller is the second input terminal of the control module; the control terminal of the microcontroller is connected to the gate of the NMOS transistor. The drain of the NMOS transistor is connected to the second terminal of the high-voltage interlock module, and the drain of the NMOS transistor is the first input terminal of the control module; the source of the NMOS transistor is grounded.

2. The circuit according to claim 1, characterized in that, The high-voltage interlock module specifically includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor; The first end of the first resistor is connected to the output end of the power module, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the first resistor is the output end of the high voltage interlock module. The second end of the second resistor is connected to the first end of the third resistor, the first end of the fourth resistor, and the first end of the fifth resistor. The second end of the second resistor is the input end of the high-voltage interlock module. The second terminals of the third resistor and the fourth resistor are grounded; the second terminal of the fifth resistor is connected to the first input terminal of the control module.

3. The circuit according to any one of claims 1-2, characterized in that, The output sampling module specifically includes: a sixth resistor, a seventh resistor, an eighth resistor, a first capacitor, and a first sampling unit; The first end of the sixth resistor is connected to the first end of the high-voltage interlock module, the first end of the sixth resistor is the sampling end of the output sampling module, the second end of the sixth resistor is connected to the first end of the seventh resistor, and the second end of the sixth resistor is connected to the first end of the eighth resistor. The second terminal of the seventh resistor is grounded; the second terminal of the eighth resistor is connected to the input terminal of the first sampling unit; the second terminal of the eighth resistor is connected to the first terminal of the first capacitor. The output terminal of the first sampling unit is connected to the second input terminal of the control module, and the output terminal of the first sampling unit is the output terminal of the output sampling module; the second terminal of the first capacitor is grounded.

4. The circuit according to any one of claims 1-2, characterized in that, The input sampling module specifically includes: a ninth resistor, a second capacitor, and a second sampling unit; The first end of the ninth resistor is connected to the input end of the high-voltage interlock module, the first end of the ninth resistor is the sampling end of the input sampling module, the second end of the ninth resistor is connected to the input end of the second sampling unit, and the second end of the ninth resistor is connected to the first end of the second capacitor. The output terminal of the second sampling unit is connected to the second input terminal of the control module, and the output terminal of the second sampling unit is the output terminal of the input sampling module; the second terminal of the second capacitor is grounded.

5. A high-voltage interlock diagnostic method, characterized in that, The method, applied to a high-voltage interlock diagnostic circuit as described in any one of claims 1-4, comprises: The output voltage is obtained through the output sampling module, and the input voltage is obtained through the input sampling module. Based on the output voltage and the input voltage, diagnose whether there is a fault in the external circuit and / or the high-voltage interlock diagnostic circuit; The diagnostic process ends when a fault occurs in the external circuit and / or the high-voltage interlock diagnostic circuit.

6. The method according to claim 5, characterized in that, The step of diagnosing whether a fault has occurred in the external circuit and / or the high-voltage interlock diagnostic circuit based on the output voltage and the input voltage specifically includes: The microcontroller of the control module outputs a high-level signal, and when the NMOS transistor of the control module is turned on, the first input voltage is obtained through the input sampling module. The microcontroller of the control module outputs a low-level signal, and when the NMOS transistor of the control module is turned off, the second input voltage is obtained through the input sampling module. When the ratio of the first input voltage to the second input voltage is within a first preset range, the external circuit and / or the high-voltage interlock diagnostic circuit are diagnosed to be working normally. When the ratio of the first input voltage to the second input voltage is not within a first preset range, the number of consecutive times the ratio of the first input voltage to the second input voltage is not within the first preset range is accumulated, and when the number of consecutive times reaches a preset number, the external circuit and / or the high-voltage interlock diagnostic circuit is diagnosed as having a fault.

7. The method according to claim 5 or 6, characterized in that, The step of diagnosing whether a fault has occurred in the external circuit and / or the high-voltage interlock diagnostic circuit based on the output voltage and the input voltage further includes: When the input voltage and the output voltage are within the preset voltage range, it is determined that the external circuit and / or the high-voltage interlock diagnostic circuit are working normally. When the input voltage and / or the output voltage are close to 0V or the power supply voltage of the power module, it is determined that the external circuit and / or the high-voltage interlock diagnostic circuit has malfunctioned.

8. The method according to claim 5 or 6, characterized in that, The step of diagnosing whether a fault has occurred in the external circuit and / or the high-voltage interlock diagnostic circuit based on the output voltage and the input voltage further includes: The calculated resistance value of the external circuit is obtained based on the output voltage, input voltage, and resistance value of the high-voltage interlock module. When the difference between the theoretical resistance value and the calculated resistance value of the external circuit is not within a second preset range, it is determined that the external circuit has malfunctioned.

9. An electric vehicle, characterized in that, The electric vehicle is equipped with an external circuit and a high-voltage interlock diagnostic circuit as described in any one of claims 1-4, wherein the external circuit is connected to the high-voltage interlock diagnostic circuit.

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