High-voltage interlocking signal detection circuit

Abstract

The utility model discloses a high voltage interlocking signal detection circuit, comprising a detection loop and a waveform modulation circuit, the waveform modulation circuit is connected with the detection loop, the waveform modulation circuit is used for generating a waveform signal in the detection loop, when the detection loop is switched from a normal state to an open circuit state, the frequency change difference of the waveform signal is obvious, and the detection loop is switched from the normal state to the open circuit state. The waveform signal frequency is not influenced by the fluctuation of a voltage source VCC and the abnormal resistance value of a resistor, thereby reducing the precision requirements of the high-voltage interlocking signal detection circuit for power supply and devices, enabling the high-voltage interlocking signal detection circuit to recognize the state of a signal loop more reliably, greatly reducing the probability of misjudgment and missed judgment of the detection circuit, and improving the reliability of the detection circuit. And the stability and the reliability of the high-voltage interlocking detection function of the electrical equipment of the new energy automobile are improved.

Description

Technical Field

[0001] This utility model relates to the field of automotive technology, and more specifically, to a high-voltage interlock signal detection circuit. Background Technology

[0002] High-voltage interlock is an indispensable safety component in the high-voltage electrical system of new energy vehicles. This component monitors the connection status of high-voltage connectors in real time. When the high-voltage connectors are disconnected during vehicle power-on or operation, this component will control the vehicle to disconnect the high-voltage power supply to avoid accidents such as high-voltage leakage and short circuits that may be caused by the disconnection of the connectors.

[0003] Traditional high-voltage interlock detection circuits, such as Figure 1 As shown, powered by VCC, resistors R1 and R2 are connected in series with the high-voltage interlock detection signal interface to form a detection loop. The detection circuit detects the voltage of V1 or V2 to determine the integrity of the high-voltage interlock signal loop. When each high-voltage connector is plugged in, the voltage source VCC forms a loop through resistors R1, the high-voltage connectors, and R2, and the voltage between the V1 and V2 voltage terminals reaches a stable value, i.e.:

[0004]

[0005] Where V1 is the voltage value at the V1 voltage terminal, and V2 is the voltage value at the V2 voltage terminal.

[0006] When the high-voltage connector is disconnected or the connection is abnormal, resistors R1 and R2 are in an open circuit state. At this time, V1 = VCC and V2 = 0V.

[0007] However, the above-mentioned high-voltage interlock detection circuit has high requirements for VCC power supply and resistor accuracy. When the VCC power supply is too low, V1 will still be lower than the alarm value after the high-voltage connector is disconnected, resulting in the phenomenon of missed high-voltage interlock alarm. When the resistance values ​​of resistors R1 and R2 are abnormal, causing a large deviation in V1 voltage or V2 voltage, it will cause the phenomenon of false high-voltage interlock alarm. Utility Model Content

[0008] In order to overcome the shortcomings of the existing technology, this utility model provides a high-voltage interlock signal detection circuit, which can effectively reduce the probability of alarm missed and false alarms, and significantly improve the stability and reliability of the high-voltage interlock detection function of electrical equipment in new energy vehicles.

[0009] The technical solution of this utility model is as follows: a high-voltage interlock signal detection circuit, including a detection circuit and a waveform modulation circuit, wherein the waveform modulation circuit is connected to the detection circuit, and the waveform modulation circuit is used to generate a waveform signal in the detection circuit.

[0010] Furthermore, the detection circuit includes a resistor R1, a plug-in module, and a resistor R2. The two ends of the plug-in module are a first node and a second node, respectively. One end of the resistor R1 is connected to a voltage source VCC, and the other end of the resistor R1 is connected to the first node. One end of the resistor R2 is connected to the second node, and the other end of the resistor R2 is grounded. The waveform modulation circuit is connected to the first node.

[0011] Furthermore, the plug-in module includes multiple high-voltage connectors connected in series. When the high-voltage connectors are disconnected, the resistors R1 and R2 are in an open-circuit state.

[0012] Furthermore, it also includes a detection circuit and a detection terminal V2, both of which are connected to the second node. The detection circuit is used to detect the waveform signal frequency of the detection terminal V2.

[0013] Furthermore, the waveform modulation circuit includes a MOS transistor Q1, the source of which is grounded and the drain of which is connected to the first node.

[0014] Furthermore, the MOS transistor Q1 is an N-channel MOS transistor.

[0015] Furthermore, the waveform signal in the detection circuit is a square wave, a sine wave, a triangular wave, or a PWM wave.

[0016] The advantages of this utility model according to the above solution are as follows: The high-voltage interlock signal detection circuit provided by this utility model includes a detection circuit and a waveform modulation circuit. The waveform modulation circuit and the detection circuit are connected. The waveform modulation circuit is used to generate a waveform signal in the detection circuit. When the detection circuit is in the normal state and switches to the open circuit state, the frequency change of the waveform signal is significantly different. The frequency of the waveform signal is not affected by the voltage source VCC fluctuation and the abnormal resistance value. This reduces the accuracy requirements of the high-voltage interlock signal detection circuit for power supply and components, makes the high-voltage interlock signal detection circuit more reliable in identifying the status of the signal circuit, greatly reduces the probability of false judgment and false omission of the detection circuit, and improves the stability and reliability of the high-voltage interlock detection function of the electrical equipment of new energy vehicles. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is an exemplary circuit diagram of an existing high-voltage interlock detection circuit;

[0019] Figure 2 This is one of the exemplary circuit diagrams of the high-voltage interlock signal detection circuit in the embodiments of this utility model;

[0020] Figure 3 This is a second exemplary circuit diagram of the high-voltage interlock signal detection circuit in this utility model embodiment. Detailed Implementation

[0021] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0022] To better understand this utility model, the following description, in conjunction with the accompanying drawings and embodiments, will further illustrate the present utility model:

[0023] See Figure 1 As shown, a traditional high-voltage interlock detection circuit is as follows: Figure 1 As shown, powered by VCC, resistors R1 and R2 are connected in series with the high-voltage interlock detection signal interface to form a detection loop. The detection circuit detects the voltage of V1 or V2 to determine the integrity of the high-voltage interlock signal loop. When each high-voltage connector is plugged in, the voltage source VCC forms a loop through resistors R1, the high-voltage connectors, and R2, and the voltage between the V1 and V2 voltage terminals reaches a stable value, i.e.:

[0024]

[0025] Where V1 is the voltage value at the V1 voltage terminal, and V2 is the voltage value at the V2 voltage terminal.

[0026] When the high-voltage connector is disconnected or the connection is abnormal, resistors R1 and R2 are in an open circuit state. At this time, V1 = VCC and V2 = 0V.

[0027] However, the above-mentioned high-voltage interlock detection circuit has high requirements for VCC power supply and resistor accuracy. When the VCC power supply is too low, V1 will still be lower than the alarm value after the high-voltage connector is disconnected, resulting in the phenomenon of missed high-voltage interlock alarm. When the resistance values ​​of resistors R1 and R2 are abnormal, causing a large deviation in V1 voltage or V2 voltage, it will cause the phenomenon of false high-voltage interlock alarm.

[0028] Based on this, the high-voltage interlock signal detection circuit provided in this embodiment is described in [reference needed]. Figure 2As shown, the high-voltage interlock signal detection circuit includes a detection circuit and a waveform modulation circuit. The waveform modulation circuit is connected to the detection circuit, and the waveform modulation circuit is used to generate a waveform signal in the detection circuit.

[0029] Specifically, a waveform modulation circuit is added to the detection circuit to generate a waveform on the high-voltage interlock detection signal detection circuit. When the high-voltage connector is connected, the detection circuit is closed, and the waveform signal can be transmitted smoothly. When the high-voltage connector is disconnected or the connection is abnormal, the detection circuit is open or disconnected, and the waveform signal cannot be transmitted, causing the V2 waveform to disappear. Thus, the integrity of the detection signal circuit can be determined by detecting the waveform. When the high-voltage connector is disconnected, the detection circuit is in an open circuit state, the waveform disappears, and the corresponding waveform cannot be detected, indicating that the high-voltage interlock signal detection circuit has failed.

[0030] It is worth mentioning that the waveform signals in this embodiment include, but are not limited to, square wave waveform signals, sine wave waveform signals, triangular wave waveform signals, or PWM wave waveform signals.

[0031] See Figures 2-3 As shown, the detection circuit includes resistor R1, a plug-in module, and resistor R2. The two ends of the plug-in module are the first node and the second node, respectively. One end of resistor R1 is connected to the voltage source VCC, and the other end of resistor R1 is connected to the first node. One end of resistor R2 is connected to the second node, and the other end of resistor R2 is grounded. The waveform modulation circuit is connected to the first node.

[0032] It is worth mentioning that the plug-in module includes multiple high-voltage connectors connected in series. When at least one of the high-voltage connectors is disconnected, resistors R1 and R2 are in an open-circuit state. In this embodiment, there are three high-voltage connectors, see [link to relevant documentation]. Figure 3 As shown, three high-voltage connectors are connected in series. Of course, the number of high-voltage connectors is not limited to three; it can be four, five, six, seven, eight, or even more. Those skilled in the art can set it according to actual needs.

[0033] Specifically, when each high-voltage connector is in the plugged-in state, the voltage source VCC forms a circuit through resistor R1, the plug-in module and resistor R2.

[0034] When the high-voltage connector is disconnected or the connection status is abnormal, the connection between the first and second nodes of the plug module is broken, and resistors R1 and R2 are in an open circuit state.

[0035] In this embodiment, the waveform modulation circuit is connected to the first node of the plug-in module. When the detection circuit is in normal working condition, the waveform modulation circuit generates a specific waveform signal and transmits it to the high-voltage interlock detection signal detection circuit through the first node. Then, the waveform signal can be detected at the corresponding detection end.

[0036] When the high-voltage connector is disconnected or the connection status is abnormal, the waveform signal will not be transmitted normally, resulting in the waveform not being transmitted to the corresponding detection terminal.

[0037] The high-voltage interlock signal detection circuit provided in this embodiment also includes a detection circuit and a detection terminal V2. Both the detection circuit and the detection terminal V2 are connected to the second node. The detection circuit is used to detect the frequency of the waveform signal of the detection terminal V2.

[0038] Specifically, the waveform modulation circuit includes a MOSFET Q1, with its source grounded and its drain connected to the first node. In this embodiment, the MOSFET Q1 is an N-channel MOSFET.

[0039] To further illustrate this point, this embodiment also provides a detection method for a high-voltage interlock signal detection circuit, as detailed below:

[0040] Powered by voltage source VCC, resistors R1 and R2 are connected in series with the high-voltage connector interlock detection signal interface. The drain of MOSFET Q1 is connected to the interlock signal line through the first node, and the source of MOSFET Q1 is grounded. A 1kHz square wave signal drives the gate of MOSFET Q1, causing the drain and source of MOSFET Q1 to conduct and cut off at a frequency of 1kHz. This generates a 1kHz square wave in the high-voltage interlock signal detection circuit. When the high-voltage interlock detection signal circuit is intact, the detection circuit can detect a 1kHz square wave at the detection terminal V2. When one of the high-voltage connectors is disconnected, the high-voltage interlock signal detection circuit is in an open circuit state, and the square wave at the detection terminal V2 disappears. That is, when the detection circuit detects that the waveform frequency at the detection terminal V2 is 0Hz, it indicates that the high-voltage interlock signal detection circuit has failed.

[0041] It is worth mentioning that the high-voltage interlock signal detection circuit provided in this embodiment shows a significant difference in the frequency change of the square wave under the two conditions of normal operation and open circuit. Even if the voltage source VCC fluctuates or the resistance values ​​of resistors R1 and R2 are abnormal, it will not affect the frequency of the square wave, thereby ensuring the reliability of the high-voltage interlock signal detection circuit and greatly reducing the probability of misjudgment and missed judgment.

[0042] The square wave frequency detection method mentioned above is just one example among many applications. Besides this, there are many other methods, including but not limited to using different types of waveforms such as sine waves and triangle waves for detection, or using waveforms of different frequencies for detection. Furthermore, methods such as detecting the duty cycle of a PWM (Pulse Width Modulation) square wave, and detecting waveforms with specific patterns, can also be used. All these methods are effective for waveform detection; the appropriate method should be selected based on the actual needs.

[0043] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

[0044] The present utility model patent has been described above with reference to the accompanying drawings. Obviously, the implementation of the present utility model patent is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present utility model patent, or the direct application of the inventive concept and technical solution of the present utility model patent to other occasions without modification, are all within the protection scope of the present utility model.

Claims

1. A high-voltage interlock signal detection circuit, characterized by, The utility model relates to a kind of detection circuit and wave modulation circuit, and the wave modulation circuit and the detection circuit are connected, and the wave modulation circuit is used to generate waveform signal in the detection circuit; The detection circuit includes resistance R1, plug-in module and resistance R2, the plug-in module two ends are first node and second node respectively, one end of the resistance R1 is connected with voltage source VCC, the other end of the resistance R1 is connected with the first node, one end of the resistance R2 is connected with the second node, the other end of the resistance R2 is grounded, and the wave modulation circuit is connected to the first node. The wave modulation circuit includes MOS tube Q1, the source of the MOS tube Q1 is grounded, and the drain of the MOS tube Q1 is connected to the first node. The plug-in module includes a plurality of high-voltage connectors connected in series, and when the high-voltage connectors are disconnected, the resistance R1 and the resistance R2 are in an open circuit state.

2. A high voltage interlock signal detection circuit as claimed in claim 1, characterized in that: Further comprising a detection circuit and a detection terminal V2, the detection circuit and the detection terminal V2 are connected to the second node, and the detection circuit is used to detect the frequency of the waveform signal of the detection terminal V2.

3. A high voltage interlock signal detection circuit as claimed in claim 2, characterized in that: The MOS tube Q1 is an N-channel MOS tube.

4. A high voltage interlock signal detection circuit as defined in claim 1, wherein: The waveform signal in the detection circuit is a square wave signal, a sine wave signal, a triangular wave signal or a PWM wave signal.

5. A high voltage interlock signal detection circuit as defined in claim 1, wherein: ​

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