High-voltage interlocking detection circuit

Abstract

The invention relates to a high-voltage interlocking detection circuit. The high-voltage interlocking detection circuit comprises a constant current source, a first voltage detection module and a resistor module. The first end of the first voltage detection module is connected with the output end of the constant current source; the first end of the resistor module is connected with the second end of the first voltage detection module and the first end of the high-voltage interlocking module, and the second end of the resistor module is connected with the second end of the high-voltage interlocking module; wherein the third end of the first voltage detection module is used for outputting a first voltage signal, and the first voltage signal is used for representing the on-off state of the high-voltage interlocking module. By adopting the circuit, the on-off state and the resistance of the high-voltage interlocking module can be detected, and the complexity and the design cost of the high-voltage interlocking detection circuit are remarkably reduced.

Description

Technical Field

[0001] This application relates to the technical field of electronic circuits, and particularly to a high-voltage interlock detection circuit. Background Art

[0002] In new energy vehicles, a high-voltage interlock (HVIL) circuit is used to ensure the safe connection of high-voltage system components. In related technologies, many HVIL circuits use pulse width modulation (PWM) signals to detect the circuit state. However, the above technologies not only increase the system cost and design complexity, but also have limited detection functions.

[0003] Therefore, it has become an urgent need in the industry to develop an HVIL circuit that is simpler, lower in cost, and capable of providing more comprehensive fault detection capabilities. Summary of the Invention

[0004] Based on this, it is necessary to provide a high-voltage interlock detection circuit.

[0005] In a first aspect, this application provides a high-voltage interlock detection circuit, which includes:

[0006] A constant current source;

[0007] A first voltage detection module, the first end of which is connected to the output end of the constant current source;

[0008] A resistor module, the first end of which is respectively connected to the second end of the first voltage detection module and the first end of the high-voltage interlock module, and the second end of which is connected to the second end of the high-voltage interlock module;

[0009] Among them, the third end of the first voltage detection module is used to output a first voltage signal, and the first voltage signal is used to characterize the on-off state of the high-voltage interlock module.

[0010] In one embodiment, the first voltage detection module includes:

[0011] A first voltage dividing unit, the first end of which is connected to the output end of the constant current source, and the second end of which is respectively connected to the first end of the resistor module and the first end of the high-voltage interlock module;

[0012] A first sampling unit, the first end of which is connected to the first end of the first voltage dividing unit, and the second end of which is used to output the first voltage signal.

[0013] In one embodiment, the first sampling unit includes:

[0014] A first sampling resistor, the first end of which is connected to the first end of the resistor module;

[0015] The second sampling resistor, the first end of the second sampling resistor is connected to the second end of the first sampling resistor, and the first end of the second sampling resistor is used to output a first voltage signal.

[0016] In one embodiment, the high-voltage interlock detection circuit further includes:

[0017] A second voltage detection module, the first end of the second voltage detection module is respectively connected to the second end of the resistor module and the second end of the high-voltage interlock module, the second end of the second voltage detection module is used to output a second voltage signal, and the second voltage signal is used to characterize the working state of the high-voltage interlock detection circuit.

[0018] In one embodiment, the second voltage detection module includes:

[0019] A second voltage dividing unit, the first end of the second voltage dividing unit is respectively connected to the second end of the resistor module and the second end of the high-voltage interlock module;

[0020] A second sampling unit, the first end of the second sampling unit is connected to the first end of the second voltage dividing unit, and the second sampling end is used to output a second voltage signal.

[0021] In one embodiment, the second voltage dividing unit includes:

[0022] A plurality of voltage dividing resistors, the voltage dividing resistors are respectively connected to the second end of the resistor module, the second end of the high-voltage interlock module, and the first end of the second sampling unit.

[0023] In one embodiment, the resistance values of the plurality of voltage dividing resistors are equal, and the high-voltage interlock detection circuit further includes:

[0024] A switch unit, the first end of the switch unit is used to access a control signal, and the second end of the switch unit is connected to the second end of the second voltage dividing unit;

[0025] A replacement resistor, the first end of the replacement resistor is connected to the third end of the switch unit, the second end of the replacement resistor is respectively connected to the second end of the resistor module and the first end of the second sampling unit, and the resistance value of the replacement resistor is equal to that of the voltage dividing resistor.

[0026] In one embodiment, the high-voltage interlock detection circuit further includes:

[0027] A control module, the control module is connected to the third end of the first voltage detection module, and the control module is used to determine the on / off state of the high-voltage interlock module according to the first voltage signal;

[0028] And / or,

[0029] The control module is used to determine the resistance value of the high-voltage interlock module according to the first voltage signal in the on state when it is determined that the high-voltage interlock module is in the on state.

[0030] In one embodiment, the high-voltage interlock detection circuit further includes:

[0031] A control module, which is respectively connected to the third terminal of the first voltage detection module and the second terminal of the second voltage detection module. The control module is configured to determine the fault conditions of the first voltage detection module and the second voltage detection module according to the first voltage signal and the second voltage signal when the high-voltage interlock module is in the conducting state.

[0032] In one embodiment, the high-voltage interlock detection circuit further includes:

[0033] A control module, which is configured to, when the high-voltage interlock module is in the conducting state, if it is detected that the first voltage signal when the switch unit accesses the control signal is equal to the first reference signal and the second voltage signal when the switch unit accesses the control signal is equal to the second reference signal, determine that there is a sampling fault at the first terminal of the second voltage detection module;

[0034] Wherein, the first reference signal is the first voltage signal when the high-voltage interlock detection circuit is not faulty and the high-voltage interlock module is in the conducting state, and the second reference signal is the second voltage signal when the high-voltage interlock detection circuit is not faulty and the high-voltage interlock module is in the conducting state.

[0035] The above high-voltage interlock detection circuit has at least the following beneficial effects:

[0036] By using a constant current source, a first voltage detection module and a resistor module, the complexity of the high-voltage interlock detection circuit is significantly reduced. This circuit does not use operational amplifiers and integrated ICs for generating PWM signals, and only requires a small amount of MCU port resources, simplifies the circuit design, and greatly reduces the design cost. More importantly, this circuit can not only accurately judge the on-off state of the high-voltage interlock module, but also detect the resistance value of the external total resistance by detecting the voltage value of the first voltage signal and combining the known resistance value, so as to detect whether there is poor contact or an increase in contact resistance in the high-voltage interlock module, discover potential problems in advance, and prevent the failure of the high-voltage interlock. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 is one of the schematic structural diagrams of the high-voltage interlock detection circuit in one embodiment;

[0039] Figure 2 The second schematic diagram of the high-voltage interlock detection circuit in an embodiment;

[0040] Figure 3 The third schematic diagram of the high-voltage interlock detection circuit in an embodiment;

[0041] Figure 4 The fourth schematic diagram of the high-voltage interlock detection circuit in an embodiment;

[0042] Figure 5 The fifth schematic diagram of the high-voltage interlock detection circuit in an embodiment;

[0043] Figure 6 The sixth schematic diagram of the high-voltage interlock detection circuit in an embodiment. Detailed implementation manners

[0044] For ease of understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0046] It can be understood that the terms "first", "second", etc. used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present application, the first resistor can be called the second resistor, and similarly, the second resistor can be called the first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0047] It can be understood that in the following embodiments, "connection", if there is an electrical signal or data transmission between the connected circuits, modules, etc., should be understood as "electrical connection", "communication connection", etc.

[0048] It can be understood that "at least one" means one or more, and "a plurality" means two or more. "At least part of an element" means part or all of the element.

[0049] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising", "including" or "having", etc., specify the presence of the stated features, integers, steps, operations, modules, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, modules, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0050] With the rapid development of new energy vehicle technology, the safety of high-voltage electrical systems has become one of the key considerations in vehicle design. High Voltage Interlock Loop (HVIL), as an important mechanism to ensure the safe operation of high-voltage systems, its reliability directly affects the safety performance of the whole vehicle. In existing high-voltage interlock detection circuits, using Pulse Width Modulation (PWM) waveform signals for status monitoring is a relatively common method. However, this method has the following limitations: First, the design of the PWM generator usually relies on dedicated integrated IC chips, which not only increases the cost of the circuit but also raises the design complexity. Second, in order to effectively monitor the PWM signal, circuits for amplitude sampling and frequency sampling need to be set at the output and input ends of the HVIL respectively, which undoubtedly increases the hardware requirements of the system and also occupies more Microcontroller Unit (MCU) resources. In addition, due to the relatively complex PWM signal detection logic, high-frequency sampling of the PWM signals at the input and output ends and comparison of the level changes are required, which not only increases the computing burden on the MCU but also may lead to misjudgment due to insufficient sampling accuracy. More importantly, the existing PWM signal detection method can only determine whether the HVIL is in the on or off state, and it is impossible to timely detect the possible poor contact and increased contact resistance of external connectors, thus making it difficult to prevent potential system failure problems in advance.

[0051] For the above reasons, in an exemplary embodiment, as Figure 1As shown in the figure, the present application provides a high-voltage interlock detection circuit, which includes: a constant current source 2, a first voltage detection module 4, and a resistor module 6. The first end of the first voltage detection module 4 is connected to the output end of the constant current source 2; the first end of the resistor module 6 is respectively connected to the second end of the first voltage detection module 4 and the first end of the high-voltage interlock module 700, and the second end of the resistor module 6 is connected to the second end of the high-voltage interlock module 700; wherein, the third end of the first voltage detection module 4 is used to output a first voltage signal, and the first voltage signal is used to characterize the on-off state of the high-voltage interlock module 700.

[0052] Among them, the constant current source 2 can refer to a power supply device that can output a fixed current. Regardless of how the load changes, the constant current source 2 can maintain the stability of the output current. The role of the constant current source 2 is to provide a stable current reference for the high-voltage interlock detection circuit, so that when the state of the high-voltage interlock module 700 changes (i.e., from on to off or from off to on), the voltage change generated by the resistor module 6 can be accurately captured by the first voltage detection module 4, thereby realizing the precise monitoring of the state of the high-voltage interlock module 700. In an automotive electronic system, a line that is always powered (such as KL30) can be connected to the positive terminal of the vehicle's small battery, so that a stable power supply can be provided for the system basis chip (SBC) in the electronic control unit (ECU) in both the vehicle's sleep and wake states. The SBC can convert the power received from KL30 into stable voltages required by various parts inside the ECU, such as 12V, 5V, etc. Among them, the 5V power supply can be used to supply power to the constant current source 2, so that the constant current source 2 outputs a constant current (such as 10mA). The high-voltage interlock module 700 includes various types of high-voltage connectors, such as BMS high-voltage connectors, electric drive high-voltage connectors, OBC high-voltage connectors, DC-DC high-voltage connectors, air-conditioning high-voltage connectors, etc. Each high-voltage connector includes a connector female head, a connector male head, and an intermediate interlock terminal in the connector female head and connector male head. By sequentially connecting the intermediate interlock terminals in each high-voltage connector, the above-mentioned high-voltage interlock module 700 is formed.

[0053] Exemplarily, when the constant current output by the constant current source 2 passes through the first voltage detection module 4 and the resistor module 6, different voltage drops will be generated at the first end of the first voltage detection module 4 and the first end of the resistor module 6 based on the resistances of the first voltage detection module 4 and the resistor module 6 themselves. Since the intermediate interlock terminals of each high-voltage connector in the high-voltage interlock module 700 have extremely small resistances, when the intermediate interlock terminals are connected in series in sequence, they can be regarded as wires. Based on this, when the high-voltage interlock module 700 is in the conducting state, the resistor module 6 is equivalent to being short-circuited by a wire, and the voltage drop generated at the first end of the first voltage detection module 4 is the product of the resistance of the first voltage detection module 4 itself and the constant current. At this time, the voltage value of the first voltage signal output is relatively low; when the high-voltage interlock module 700 is in the open state, the resistor module 6 is not short-circuited by a wire, and the voltage drop generated at the first end of the first voltage detection module 4 is the product of the combined resistances of the first voltage detection module 4 and the resistor module 6 themselves and the constant current. At this time, the voltage value of the first voltage signal output is relatively high. Therefore, control modules such as the MCU can obtain the voltage drop at the first end of the first voltage detection module 4 based on the first voltage signal output by the first voltage detection module 4, so as to determine the conducting state of the high-voltage interlock module 700. In addition, in the circuit selection and design, usually the resistance values of the resistor module 6 and the first voltage detection module 4 are determined. Therefore, control modules such as the MCU can also, when determining that the high-voltage interlock module 700 is in the conducting state based on the first voltage signal, combine the resistance value of the resistor module 6 and the resistance value of the first voltage detection module 4, and through Ohm's law, determine the resistance of the high-voltage interlock module 700, so as to detect whether there are problems such as poor contact or increased contact resistance in the high-voltage interlock module 700, discover problems in advance, and thus prevent high-voltage interlock failure.

[0054] In this embodiment, by using the constant current source 2, the first voltage detection module 4, and the resistor module 6, the complexity of the high-voltage interlock detection circuit is significantly reduced. This circuit does not use operational amplifiers and integrated ICs for generating PWM signals, and only requires a small amount of MCU port resources, simplifies the circuit design, and greatly reduces the design cost. More importantly, this circuit can not only accurately judge the on-off state of the high-voltage interlock module 700, but also detect the resistance value of the external total resistance by detecting the voltage value of the first voltage signal and combining the known resistance values, so as to detect whether there are problems such as poor contact or increased contact resistance in the high-voltage interlock module 700, discover potential problems in advance, and prevent high-voltage interlock failure.

[0055] In an exemplary embodiment, the high-voltage interlock detection circuit further includes a control module. The control module is connected to the third terminal of the first voltage detection module 4, and the control module is configured to determine the on / off state of the high-voltage interlock module 700 according to the first voltage signal; and / or, the control module is configured to determine the resistance value of the high-voltage interlock module 700 according to the first voltage signal in the on state when it is determined that the high-voltage interlock module 700 is in the on state.

[0056] Exemplarily, the high-voltage interlock detection circuit may further include a control module integrated together. As described in the above embodiment, the control module can determine the on / off state of the high-voltage interlock module 700 based on the first voltage signal, and can also determine the resistance value of the high-voltage interlock module 700 according to the first voltage signal in the on state when it is determined that the high-voltage interlock module 700 is in the on state. The specific determination process can refer to the description in the above embodiment and will not be elaborated here.

[0057] In this embodiment, by introducing the control module, not only can the on / off state of the high-voltage interlock module 700 be accurately judged according to the first voltage signal, but also when the high-voltage interlock module 700 is in the on state, the resistance value of the high-voltage interlock module 700 can be determined by analyzing the first voltage signal, so as to detect whether there is poor contact or an increase in contact resistance. The circuit structure is simplified, the design cost and complexity are reduced, and the monitoring ability and fault prediction ability of the system are improved, ensuring the stability and safety of the high-voltage interlock system.

[0058] In an exemplary embodiment, as Figure 2 shown, the first voltage detection module 4 includes a first voltage division unit 42 and a first sampling unit 44. The first end of the first voltage division unit 42 is connected to the output end of the constant current source 2, and the second end of the first voltage division unit 42 is respectively connected to the first end of the resistance module 6 and the first end of the high-voltage interlock module 700; the first end of the first sampling unit 44 is connected to the first end of the first voltage division unit 42, and the second end of the first sampling unit 44 is used to output the first voltage signal.

[0059] Exemplarily, the high-voltage interlock detection circuit provides a constant current through the constant current source 2, and this current passes through the first voltage division unit 42 and the resistance module 6. The resistance values of the first voltage division unit 42 and the resistance module 6 determine the voltage drop in different high-voltage interlock states. The first sampling unit 44 detects the voltage at the first end of the first voltage division unit 42 and outputs the first voltage signal. When the high-voltage interlock module 700 is on, the resistance module 6 is short-circuited, and the voltage value of the first voltage signal is low; when the high-voltage interlock module 700 is off, the current passes through the resistance module 6, and the voltage value of the first voltage signal is high. By detecting the change in the voltage value of the first voltage signal, the on / off state of the high-voltage interlock module 700 can be accurately judged, thus realizing simple, low-cost and efficient monitoring of the high-voltage interlock detection circuit.

[0060] In this embodiment, by using the constant current source 2, the first voltage dividing unit 42, and the first sampling unit 44, the design of the high-voltage interlock detection circuit is significantly simplified. This design does not rely on complex PWM signal generation and processing circuits, avoiding the use of expensive integrated ICs, thus reducing the cost and design complexity. At the same time, this circuit only needs to occupy a small amount of MCU port resources, further simplifying the system design. By detecting the change of the first voltage signal, the on-off state of the high-voltage interlock module 700 can be accurately judged, realizing simple, low-cost, and efficient monitoring of the high-voltage interlock detection circuit, and improving the reliability and economy of the system.

[0061] In an exemplary embodiment, the first sampling unit 44 includes a first sampling resistor and a second sampling resistor. The first end of the first sampling resistor is connected to the first end of the resistor module 6; the first end of the second sampling resistor is connected to the second end of the first sampling resistor, and the first end of the second sampling resistor is used to output the first voltage signal.

[0062] Exemplarily, the common end between the first sampling resistor and the second sampling resistor is used as the output end of the first voltage signal, and the precise measurement of the voltage signal is realized through the voltage dividing network. The combination of the first sampling resistor and the second sampling resistor can divide the voltage signal generated by the constant current source 2 through the resistor module 6, so as to output a voltage signal suitable for the input range of the ADC port of the MCU at the first end of the second sampling resistor.

[0063] In this embodiment, by using the sampling unit composed of the first sampling resistor and the second sampling resistor, the design of the high-voltage interlock detection circuit is further simplified. It not only reduces the dependence on external complex circuits, reduces the cost and design complexity, but also realizes the precise detection of the on-off state of the high-voltage interlock module 700 through a simple resistor voltage dividing network. The output of the first voltage signal only needs to be completed through two sampling resistors, occupying extremely few MCU port resources, improving the reliability and economy of the system, and ensuring the accuracy and response speed of the detection.

[0064] In an exemplary embodiment, as Figure 3 shown, the high-voltage interlock detection circuit further includes a second voltage detection module 8. The first end of the second voltage detection module 8 is respectively connected to the second end of the resistor module 6 and the second end of the high-voltage interlock module 700. The second end of the second voltage detection module 8 is used to output a second voltage signal, and the second voltage signal is used to characterize the working state of the high-voltage interlock detection circuit.

[0065] Exemplarily, when it is determined that the high-voltage interlock module 700 is in a conducting state, based on the above high-voltage interlock detection circuit, a second voltage detection module 8 can also be added to detect the voltage drop at the second end of the resistor module 6 and output it in the form of a second voltage signal to a control module such as an MCU, so that the control module such as an MCU can complete the self-check of the high-voltage interlock detection circuit based on the first voltage signal and in combination with the second voltage signal. For example, when an open circuit occurs between the first end and the second end of the first voltage detection module 4, since the constant current output by the constant current source 2 cannot flow to the resistor module 6 and the second voltage detection module 8, the voltage value of the second voltage signal will be zero, and the voltage value of the first voltage signal is proportional to the supply voltage of the constant current source 2. Therefore, when the voltage value of the output first voltage signal is proportional to the supply voltage of the constant current source 2 and the voltage value of the output second voltage signal is zero, the two output voltage signals can then represent that an open circuit has occurred between the first end and the second end of the first voltage detection module 4 in the high-voltage interlock detection circuit. Another example is when an open circuit occurs between the first end and the third end of the first voltage detection module 4. Since the constant current of the constant current source 2 cannot flow to the third end of the first voltage detection module 4 but can normally flow through the resistor module 6 and the first voltage module between the first end and the second end of the first voltage detection module 4, the voltage value of the first voltage signal will be zero, and the voltage value of the second voltage signal is the product of the resistance of the second voltage module itself and the constant current. Therefore, when the voltage value of the output first voltage signal is zero and the voltage value of the output second voltage signal is the product of the resistance of the second voltage module itself and the constant current, the two output voltage signals can then represent that an open circuit has occurred between the first end and the third end of the first voltage detection module 4 in the high-voltage interlock detection circuit. Another example is when the second end of the first voltage detection module 4 or the first end of the second voltage detection module 8 is short-circuited to the ground. The voltage value of the first voltage signal is the product of the resistance of the first voltage detection module 4 itself and the constant current, and the voltage value of the second voltage signal is zero. Therefore, when the voltage value of the output first voltage signal is the product of the resistance of the first voltage detection module 4 itself and the constant current and the voltage value of the second voltage signal is zero, the two output voltage signals can then represent that the second end of the first voltage detection module 4 or the first end of the second voltage detection module 8 in the high-voltage interlock detection circuit is short-circuited to the ground. Through the second voltage signal of the second voltage detection module 8 and in combination with the first voltage signal, in addition to being able to achieve the fault diagnosis of the first voltage detection module 4 as described above, other fault diagnoses of the high-voltage interlock detection circuit (such as a short circuit of the first voltage detection module 4 or the second voltage detection module 8 to the power supply, etc.) can also be achieved. The specific diagnosis process will not be elaborated here, and those skilled in the art can learn based on the structure of this high-voltage interlock detection circuit.

[0066] In this embodiment, by introducing the second voltage detection module 8, the self-checking ability and fault diagnosis ability of the high-voltage interlock detection circuit are significantly enhanced. This module can detect and output a second voltage signal reflecting the working state of the high-voltage interlock detection circuit. Combining with the first voltage signal, various possible fault types in the circuit, such as open circuit, short circuit, etc., can be accurately judged, thus greatly improving the reliability and safety of the system.

[0067] In an exemplary embodiment, the high-voltage interlock detection circuit further includes a control module. The control module is respectively connected to the third terminal of the first voltage detection module 4 and the second terminal of the second voltage detection module 8. The control module is used to determine the fault conditions of the first voltage detection module 4 and the second voltage detection module 8 according to the first voltage signal and the second voltage signal when the high-voltage interlock module 700 is in the conducting state.

[0068] Exemplarily, the high-voltage interlock detection circuit may further include an integrated control module. As described in the above embodiment, the control module can determine the fault conditions of the first voltage detection module 4 and the second voltage detection module 8 based on the first voltage signal and the second voltage signal. The specific determination process can refer to the description in the above embodiment and will not be elaborated here.

[0069] In this embodiment, by integrating the control module, the automatic detection and diagnosis of the fault conditions of the first voltage detection module 4 and the second voltage detection module 8 in the high-voltage interlock detection circuit are realized. The control module can accurately judge the working state and fault types of each part of the circuit based on the analysis of the first voltage signal and the second voltage signal, effectively improving the self-monitoring ability and fault response speed of the system, enhancing the reliability and safety of the system, simplifying the fault troubleshooting process at the same time, and reducing the maintenance cost.

[0070] In an exemplary embodiment, as Figure 4 shown, the second voltage detection module 8 includes a second voltage dividing unit 82 and a second sampling unit 84. The first terminal of the second voltage dividing unit 82 is respectively connected to the second terminal of the resistor module 6 and the second terminal of the high-voltage interlock module 700; the first terminal of the second sampling unit 84 is connected to the first terminal of the second voltage dividing unit 82, and the second sampling terminal is used to output the second voltage signal.

[0071] In this embodiment, through the design of the second voltage dividing unit 82 and the second sampling unit 84 in the second voltage detection module 8, the voltage of a specific node in the circuit can be effectively and accurately detected, and the second voltage signal is output through the second sampling unit 84 to realize the real-time monitoring of the circuit state. This not only improves the accuracy and reliability of voltage detection, simplifies the circuit structure, reduces the system cost, but also enhances the safety and stability of the system, and is particularly suitable for application scenarios that require high-precision voltage monitoring, such as the high-voltage system monitoring of electric vehicles, etc.

[0072] In an exemplary embodiment, the second voltage dividing unit 82 includes a plurality of voltage dividing resistors. The voltage dividing resistors are respectively connected to the second end of the resistor module 6, the second end of the high-voltage interlock module 700, and the first end of the second sampling unit 84.

[0073] Exemplarily, by connecting a plurality of voltage dividing resistors in parallel, the redundancy of the circuit can be increased. Even if one or several of the resistors fail, the other resistors can still continue to work, ensuring the normal operation of the basic function of the high-voltage interlock detection circuit for detecting the on / off state of the high-voltage interlock module 700. Secondly, by connecting a plurality of resistors in parallel, the total resistance value can be finely adjusted by selecting resistors with different resistance values, so as to more precisely achieve the required voltage division ratio.

[0074] In an exemplary embodiment, as Figure 5 shown, the resistance values of the plurality of voltage dividing resistors are equal, and the high-voltage interlock detection circuit further includes a switch unit 10 and a replacement resistor 12. The first end of the switch unit 10 is used to access a control signal, and the second end of the switch unit 10 is connected to the second end of the second voltage dividing unit 82; the first end of the replacement resistor 12 is connected to the third end of the switch unit 10, and the second end of the replacement resistor 12 is respectively connected to the second end of the resistor module 6 and the first end of the second sampling unit 84, and the resistance value of the replacement resistor 12 is equal to that of the voltage dividing resistor.

[0075] Exemplarily, by using a plurality of voltage dividing resistors with equal resistance values and the replacement resistor 12, when one of the plurality of voltage dividing resistors fails, based on the on / off control of the switch unit 10, the replacement resistor 12 can be connected in parallel with the other resistors except the failed voltage dividing resistor, so that the voltage value of the second voltage signal output by the second sampling unit 84 returns to normal. For example, assuming there are two voltage dividing resistors, when the switch unit 10 does not receive a control signal, the switch unit 10 remains in the open state, and the replacement resistor 12 is not connected in parallel with the voltage dividing resistor. At this time, the voltage value of the second voltage signal output by the second sampling unit 84 is the product of the resistance value of the two voltage dividing resistors in parallel and the constant current. When the voltage value of the second voltage signal becomes larger, the switch unit 10 can be closed based on the drive of the control signal, so that the replacement resistor 12 is connected in parallel with the voltage dividing resistor. At this time, the voltage value of the second voltage signal just returns to the product of the resistance value of the two voltage dividing resistors in parallel and the constant current, indicating that one of the two voltage dividing resistors has failed, thereby confirming the sampling failure at the first end of the second voltage detection module 8.

[0076] In this embodiment, by using a plurality of voltage-dividing resistors with equal resistance values and replacing resistor 12, and combining with the control of switch unit 10, the first-end sampling fault of the second voltage detection module 8 can be quickly detected and confirmed. When it is detected that the voltage value of the second voltage signal abnormally increases, the switch unit 10 is driven to close based on the control signal, and the replacement resistor 12 is connected in parallel to the circuit. If the voltage value of the second voltage signal returns to the normal level, it is immediately confirmed that one of the voltage-dividing resistors fails. This not only realizes the rapid detection and location of the fault, but also can automatically repair the fault without interrupting the circuit operation, greatly improving the reliability and maintenance efficiency of the system.

[0077] In an exemplary embodiment, the high-voltage interlock detection circuit further includes a control module. The control module is configured to determine the first-end sampling fault of the second voltage detection module 8 when, in the case that the high-voltage interlock module 700 is in a conducting state, it is detected that the first voltage signal when the switch unit 10 accesses the control signal is equal to the first reference signal, and the second voltage signal when the switch unit 10 accesses the control signal is equal to the second reference signal; wherein, the first reference signal is the first voltage signal when the high-voltage interlock detection circuit is not faulty and the high-voltage interlock module 700 is in a conducting state, and the second reference signal is the second voltage signal when the high-voltage interlock detection circuit is not faulty and the high-voltage interlock module 700 is in a conducting state.

[0078] Exemplarily, the high-voltage interlock detection circuit can also integrate a control module. By the control module, in the conducting state of the high-voltage interlock module 700, combining with the control signal of the switch unit 10, comparing the first voltage signal and the second voltage signal with the preset first reference signal and second reference signal, the first-end sampling fault of the second voltage detection module 8 can be quickly and accurately detected and determined. This not only improves the accuracy and speed of fault detection, but also realizes automatic fault diagnosis, reduces the need for manual intervention, and enhances the reliability and maintenance efficiency of the system.

[0079] In one embodiment, to describe the technical solution of the present application in more detail, the following is combined with the attached Figure 6 for illustration.

[0080] As Figure 6As shown, the high-voltage interlock detection circuit of the present application specifically includes a constant current source A1, a first voltage detection module 4, a resistor module 6, and a second voltage detection module 8. Among them, in the automotive electronic system, the power supply voltage of the constant current source A1 can be the 5V voltage output on the board after the 12V voltage input by the live line KL30 is subjected to reverse protection, filtering, boosting, buck conditioning circuits, and a system basis chip (SBC) by the automotive electronic control unit (ECU). The 12V voltage output by the SBC is also included and is used to supply power to other components of the automotive electronic system. Under the action of the 5V power supply voltage, the constant current source A1 outputs a constant current of 10mA. The first voltage detection module 4 specifically includes a first voltage division unit 42 composed of a resistor R1 and a first sampling unit 44 composed of a first sampling resistor R9 and a second sampling resistor R11. The HVIL_OUT_AI port is the port for outputting the first voltage signal V HVIL_OUT_AI . The resistor module 6 mainly includes a resistor R2. The two ends of the resistor R2 are used to be connected in parallel to a high-voltage interlock module 700 composed of a BMS high-voltage connector, an electric drive high-voltage connector, an OBC high-voltage connector, a DC-DC high-voltage connector, and an air-conditioning high-voltage connector connected in series in sequence. The second voltage detection module 8 specifically includes a second voltage division unit 82 composed of a first voltage division resistor R3 and a second voltage division resistor R4 connected in parallel and a second sampling unit 84 composed of a resistor R6. On this basis, the high-voltage interlock detection circuit of the present application further includes a replacement resistor 12 composed of a resistor R5 and a switch unit 10 composed of a MOS transistor Q12. The first end of the switch unit 10, that is, the gate of the MOS transistor, is also connected to the HVIL_DIG port through a resistor R7 and a resistor R8 to receive a control signal. The HVIL_IN_AI port is the port for outputting the second voltage signal V HVIL_IN_A . Among them, the resistance values of each resistor can be directly obtained by those skilled in the art from the figure.

[0081] When the high-voltage interlock module 700 is in the off state, at this time the MOS transistor is in the off state, and the first voltage signal V output by the HVIL_OUT_AI port HVIL_OUT_AII =(R1 + R2 + R3 / / R4)×10mA = (33 + 200 + 150)×10 = 3830mV, and the second voltage signal V output by the HVIL_IN_AI port HVIL_IN_A =(R3 / / R4)×10mA = 150×10 = 1500mV; when the high-voltage interlock module 700 is in the on state, at this time the MOS transistor is still in the off state, and the first voltage signal V output by the HVIL_OUT_AI port HVIL_OUT_AII=(R1 + R3 / / R4)×10mA = (33 + 150)×10 = 1830mV, the second voltage signal V output by the HVIL_IN_AI port HVIL_IN_A =(R3 / / R4)×10mA = 150×10 = 1500mV. Through the above first voltage signal V HVIL_OUT_AII the external high-voltage interlock state can be judged. When V HVIL_OUT_AI = 3830mV, it can be determined that it is completely disconnected. When V HVIL_OUT_AI = 1830mV, it can be determined that it is fully connected and the high-voltage interlock resistance is zero. However, in fact, the high-voltage interlock resistance is generally not zero. Therefore, when the first voltage signal V HVIL_OUT_AI is between 1830mV and 3830mV, the resistance of the high-voltage interlock module 700 can be determined based on Ohm's law. Assuming the resistance of the high-voltage interlock module 700 is Rx, there is V HVIL_OUT_AI =(R1 + R2 / / Rx + R3 / / R4)×10mA. After simplification, the expression for the resistance Rx of the high-voltage interlock module 700 is obtained: Rx = (20000V HVIL_OUT_AI - 37000) / (385 - 100V HVIL_OUT_AI ), where V HVIL_OUT_AI is in volts V. Therefore, in the case of detecting the voltage value of the first voltage signal, based on the above expression for the resistance Rx of the high-voltage interlock module 700, the resistance of the high-voltage interlock module 700 can be obtained.

[0082] In addition, when the high-voltage interlock module 700 is in the conducting state, the self-check of the high-voltage interlock detection circuit can also be completed based on the above first voltage signal and second voltage signal output.

[0083] When the resistance R1 of the first voltage sampling module is open, the constant current output by the constant current source A1 forms a loop through the first sampling resistor R9 and the second sampling resistor R11 to the ground. However, since the resistance of the first sampling resistor R9 and the second sampling resistor R11 is 10kΩ, theoretically the voltage drop obtained based on the voltage division on the resistor R11 is 10kΩ×10mA = 100V. But in fact, since the output voltage of the constant current source A1 cannot be greater than the supply voltage of 5V, the first voltage signal V HVIL_OUT_AI = 2.5V, and the second voltage signal V HVIL_IN_AI = 0V; therefore, based on the above conditions, the open-circuit fault of the resistor R1 can be determined.

[0084] When the resistance R9 of the first voltage sampling module is open, the constant current output by the constant current source A1 forms a loop through the resistor R1, the high-voltage interlock module 700, the resistor R3, and the resistor R4 to the ground. So the first voltage signal V HVIL_OUT_AI = 0V, and the second voltage signal V HVIL_IN_AI=(R3 / / R4)×10 mA = 150×10 = 1500 mV. Therefore, based on the above conditions, the open - circuit fault of resistor R9 can be determined.

[0085] When resistor R3 or resistor R4 is open - circuit and the level of the gate of the MOS transistor is set to low level, the MOS transistor is in the off state at this time. At this time, the first voltage signal V HVIL_OUT_AI =(33 + 300)×10 mA = 3330 mV, and the second voltage signal V HVIL_IN_AI = 300×10 mA = 3000 mV; input a control signal to the HVIL_DIG port, that is, set the level of the gate of the MOS transistor to high level. Replace the resistor 12R5 and it will be in parallel with resistor R3 or resistor R4. At this time, the first voltage signal V HVIL_OUT_AI =(33 + 150)×10 mA = 1830 mV, and the second voltage signal V HVIL_IN_AI =(150)×10 mA = 1500 mV. By comparing and analyzing the above - mentioned first voltage signal and second voltage signal, it can be determined whether there is a fault in the sampling of the first terminal of the above - mentioned first voltage detection module 4.

[0086] When one end of resistor R2 is short - circuited to the 12V power supply output by the SBC, the first voltage signal V HVIL_OUT_AI = 12V, and the second voltage signal V HVIL_IN_AI = 12V. Therefore, based on the above conditions, it can be determined that the high - voltage interlock detection circuit has a short - power - supply fault; similarly, when one end of resistor R2 is short - circuited to the ground, the first voltage signal V HVIL_OUT_AI = R1×10 mA ≈ 330 mV, and the second voltage signal V HVIL_IN_AI = 10V. Therefore, based on the above conditions, it can be determined that the high - voltage interlock detection circuit has a short - to - ground fault.

[0087] In this embodiment, the selection of the above - mentioned various electronic components can be made according to actual design requirements. The specific values of the above - mentioned various electronic components, as well as the on - off state judgment process of the high - voltage interlock module, the resistor determination process of the high - voltage interlock module, and the self - diagnosis process of the high - voltage interlock detection circuit based on the above - mentioned specific values are only for illustrative purposes and are not limited here. In the above - mentioned embodiment, by replacing the complex PWM signal with a common voltage signal, the use of MCU port resources is significantly reduced. At the same time, the use of the PWM generator is abandoned, reducing the development cost and the complexity of the circuit design. The design of the high - voltage interlock detection circuit can be realized only by using ordinary resistors and NMOS transistors, which not only simplifies the circuit structure but also has the ability to collect the resistance values of external resistors. More importantly, this circuit design has a powerful self - diagnosis function, can quickly and accurately detect and locate various faults, and the built - in safety mechanism meets the requirements of the functional safety level ASIL B, thus greatly improving the reliability and safety of the system.

[0088] In an exemplary embodiment, the present application further provides a vehicle, including a high-voltage interlock module and a high-voltage interlock detection circuit as described in the above embodiment.

[0089] In this embodiment, by integrating a high-voltage interlock module and an improved high-voltage interlock detection circuit in the vehicle, the safety and reliability of the vehicle electrical system are significantly improved. The detection circuit can quickly and accurately detect the on / off state of the high-voltage interlock module and circuit faults, especially common faults such as open circuits and short circuits in the high-voltage system, so as to take timely measures to prevent potential safety hazards. This not only enhances the vehicle's self-monitoring and fault diagnosis capabilities, but also simplifies the maintenance process, reduces the maintenance cost, and ensures the long-term stable operation of the vehicle.

[0090] In the description of this specification, the description with reference to terms such as "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0091] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0092] The above-described embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A high voltage interlock detection circuit, characterized in that: The high voltage interlock detection circuit comprises: Constant current source; A first voltage detection module, wherein a first end of the first voltage detection module is connected to an output end of the constant current source; A resistance module, wherein a first end of the resistance module is respectively connected to a second end of the first voltage detection module and a first end of a high-voltage interlocking module, and a second end of the resistance module is connected to a second end of the high-voltage interlocking module; The third terminal of the first voltage detection module is used to output a first voltage signal, and the first voltage signal is used to represent the on / off state of the high-voltage interlocking module.

2. The high voltage interlock detection circuit according to claim 1, characterized in that: The first voltage detection module includes: A first voltage dividing unit, wherein a first end of the first voltage dividing unit is connected to an output end of the constant current source, and a second end of the first voltage dividing unit is respectively connected to a first end of the resistance module and a first end of the high-voltage interlocking module; A first sampling unit, wherein a first end of the first sampling unit is connected to a first end of the first voltage dividing unit, and a second end of the first sampling unit is used to output the first voltage signal.

3. The high voltage interlock detection circuit according to claim 2, characterized in that: The first sampling unit comprises: A first sampling resistor, wherein a first end of the first sampling resistor is connected to a first end of the resistor module; A second sampling resistor, wherein a first end of the second sampling resistor is connected to the second end of the first sampling resistor, and the first end of the second sampling resistor is used to output the first voltage signal.

4. The high voltage interlock detection circuit according to any one of claims 1 to 3, characterized in that: The high voltage interlock detection circuit also includes: A second voltage detection module, wherein the first end of the second voltage detection module is respectively connected to the second end of the resistance module and the second end of the high-voltage interlock module, and the second end of the second voltage detection module is used to output a second voltage signal, and the second voltage signal is used to characterize the working state of the high-voltage interlock detection circuit.

5. The high voltage interlock detection circuit according to claim 4, characterized in that: The second voltage detection module includes: A second voltage dividing unit, wherein a first end of the second voltage dividing unit is respectively connected to a second end of the resistance module and a second end of the high-voltage interlocking module; A second sampling unit, wherein a first end of the second sampling unit is connected to a first end of the second voltage dividing unit, and the second sampling end is used to output the second voltage signal.

6. The high voltage interlock detection circuit according to claim 5, characterized in that: The second voltage dividing unit comprises: A plurality of voltage-dividing resistors are respectively connected to the second end of the resistor module, the second end of the high-voltage interlocking module, and the first end of the second sampling unit.

7. The high voltage interlock detection circuit according to claim 6, characterized in that: The resistance values ​​of the plurality of voltage-dividing resistors are equal, and the high-voltage interlock detection circuit further includes: A switch unit, wherein a first end of the switch unit is used to receive a control signal, and a second end of the switch unit is connected to a second end of the second voltage dividing unit; A replacement resistor, wherein the first end of the replacement resistor is connected to the third end of the switch unit, the second end of the replacement resistor is respectively connected to the second end of the resistor module and the first end of the second sampling unit, and the resistance values ​​of the replacement resistor and the voltage divider resistor are equal.

8. The high voltage interlock detection circuit according to claim 1, characterized in that: The high voltage interlock detection circuit also includes: A control module, the control module is connected to the third end of the first voltage detection module, and the control module is used to determine the on / off state of the high-voltage interlocking module according to the first voltage signal; and / or, The control module is used for determining the resistance value of the high-voltage interlocking module according to a first voltage signal in the on state when it is determined that the high-voltage interlocking module is in the on state.

9. The high voltage interlock detection circuit according to claim 4, characterized in that: The high voltage interlock detection circuit also includes: A control module, wherein the control module is respectively connected to the third end of the first voltage detection module and the second end of the second voltage detection module, and the control module is used to determine the fault conditions of the first voltage detection module and the second voltage detection module according to the first voltage signal and the second voltage signal when the high-voltage interlocking module is in an on state.

10. The high voltage interlock detection circuit according to claim 7, characterized in that: The high voltage interlock detection circuit also includes: A control module, wherein the control module is used to determine that a first-end sampling fault of the second voltage detection module occurs when the high-voltage interlocking module is in an on state and if it is detected that a first voltage signal when the switch unit is connected to the control signal is equal to a first reference signal and a second voltage signal when the switch unit is connected to the control signal is equal to a second reference signal; Among them, the first reference signal is a first voltage signal when the high-voltage interlock detection circuit is not faulty and the high-voltage interlock module is in the on state, and the second reference signal is a second voltage signal when the high-voltage interlock detection circuit is not faulty and the high-voltage interlock module is in the on state.

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