Charging gun detection and protection circuit and charging gun

Abstract

The utility model discloses a charging gun detection and protection circuit and a charging gun, and relates to the technical field of automobile charging protection. The charging gun detection and protection circuit comprises a power supply module, a zero line voltage detection module, a live wire voltage detection module, a grounding detection module, a relay driving module and a relay. The power module comprises a live wire, a zero wire and a ground wire. The live wire voltage detection module is used for detecting voltage of a live wire; the null line voltage detection module is electrically connected with a null line and used for detecting the voltage of the null line; the grounding detection module is used for detecting the voltage of a ground wire; and the relay driving module is electrically connected with the relay and is used for driving the relay to be switched on or switched off. According to the charging gun voltage detection device, the live wire voltage, the zero line voltage and the grounding condition of the charging gun can be comprehensively detected, the problems that an existing charging gun voltage detection mode is single, comprehensive detection cannot be achieved, and detection is inaccurate and unreliable are solved, voltage detection of the charging gun is achieved, and the safety of circuits and devices is protected.

Description

Technical Field

[0001] The present application relates to the technical field of automobile charging protection, and in particular to a charging gun detection and protection circuit and a charging gun. Background Art

[0002] A malfunction in a car charging gun can easily lead to safety issues. For example, if the input voltage is too high or the user plugs in the wrong power source, overvoltage can easily cause the gun to breakdown, damaging components like the power supply circuit and varistor. Therefore, voltage detection on the gun is essential to protect the circuits and components. However, existing voltage detection methods are limited and incomplete, resulting in inaccurate and unreliable detection. Utility Model Content

[0003] Purpose of the invention: The embodiment of the present application provides a charging gun detection and protection circuit, aiming to overcome the technical problems in the prior art that the voltage detection method is relatively single and cannot achieve comprehensive detection, resulting in inaccurate and unreliable detection; another purpose of the embodiment of the present application is to provide a charging gun.

[0004] Technical solution: A charging gun detection and protection circuit according to an embodiment of the present application includes:

[0005] Power supply module, neutral voltage detection module, live voltage detection module, ground detection module, relay drive module and relay;

[0006] Wherein, the power supply module includes a live wire, a neutral wire and a ground wire; the live wire voltage detection module is electrically connected to the live wire and coupled to the relay drive module for detecting the voltage of the live wire;

[0007] The neutral line voltage detection module is electrically connected to the neutral line and coupled to the relay driving module, and is used to detect the voltage of the neutral line;

[0008] The ground detection module is electrically connected to the neutral wire and the live wire respectively, and is coupled to the relay driving module, for detecting the voltage of the ground wire;

[0009] The relay driving module is electrically connected to the relay and is used to drive the relay to be turned on or off.

[0010] Accordingly, a charging gun described in an embodiment of the present application is applied to a vehicle, and the charging gun includes the charging gun detection and protection circuit described above.

[0011] Beneficial Effects: Compared with the prior art, the charging gun detection and protection circuit and charging gun of the present invention include: a power supply module, a neutral voltage detection module, a live voltage detection module, a ground detection module, a relay driver module, and a relay. The power supply module includes a live wire, a neutral wire, and a ground wire. The live voltage detection module is electrically connected to the live wire and coupled to the relay driver module for detecting the voltage of the live wire. The neutral voltage detection module is electrically connected to the neutral wire and coupled to the relay driver module for detecting the voltage of the neutral wire. The ground detection module is electrically connected to the neutral wire and the live wire, respectively, and coupled to the relay driver module for detecting the voltage of the ground wire. The relay driver module is electrically connected to the relay for driving the relay on or off. Thus, the circuit can achieve: comprehensive detection of the live wire voltage, neutral wire voltage, and grounding status of the charging gun, thereby resolving the problem that the existing charging gun voltage detection method is relatively simple, cannot achieve comprehensive detection, and causes inaccurate and unreliable detection. The circuit can achieve voltage detection of the charging gun to protect the safety of the circuit and devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0013] Figure 1 This is a principle structure block diagram of a charging gun detection and protection circuit provided in an embodiment of the present application;

[0014] Figure 2 This is a principle structure block diagram of another charging gun detection and protection circuit provided in an embodiment of the present application;

[0015] Figure 3 1 is a schematic diagram of the circuit structure of a relay driver module provided in an embodiment of the present application;

[0016] Figure 4 1 is a circuit diagram of a live wire voltage detection module provided in an embodiment of the present application;

[0017] Figure 5 1 is a circuit structure diagram of a neutral voltage detection module provided in an embodiment of the present application;

[0018] Figure 6 1 is a schematic diagram of the circuit structure of a ground detection module provided in an embodiment of the present application;

[0019] Figure 7This is a schematic diagram of the structure of the first half cycle of alternating current provided in an embodiment of the present application;

[0020] Figure 8 This is a schematic diagram of current flow when a grounding anomaly is provided in an embodiment of the present application;

[0021] Figure 9 Schematic diagram of a fitting curve provided in the embodiment of the present application;

[0022] Figure 10 This is a principle structure block diagram of another charging gun detection and protection circuit provided in an embodiment of the present application;

[0023] Figure 11 This is a principle structure block diagram of another charging gun detection and protection circuit provided in an embodiment of the present application;

[0024] Figure 12 1 is a schematic diagram of a circuit structure of a relay detection module provided in an embodiment of the present application;

[0025] Figure 13 This is a schematic diagram of a signal output by a first optocoupler output terminal before a relay is closed, provided in an embodiment of the present application;

[0026] Figure 14 This is a schematic diagram of a signal output from a first optocoupler output terminal after a relay is closed, provided in an embodiment of the present application;

[0027] Figure 15 This is a schematic structural diagram of an EMC filter circuit provided in an embodiment of the present application;

[0028] Figure 16 It is a structural diagram of a switching power supply circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0030] It should be understood that although the terms first, second, etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another. Thus, the first component discussed below could be referred to as the second component without departing from the teachings of the present invention. As used herein, the term "and / or" includes any one and all combinations of one or more of the associated listed items.

[0031] Those skilled in the art will appreciate that the drawings are merely schematic diagrams of exemplary embodiments and may not be to scale. The modules or processes in the drawings are not necessarily required to implement the present application and therefore cannot be used to limit the scope of protection of the present application.

[0032] Figure 1 This is a schematic diagram of the principle structure of a charging gun detection and protection circuit provided in the embodiment of this application. Figure 1 The charging gun detection and protection circuit includes: a power module 10, a neutral line voltage detection module 20, a live line voltage detection module 30, a ground detection module 40, a relay drive module 50, a relay 60 and a control module 70; wherein the power module 10 includes a live line L, a neutral line N and a ground line PE; the live line voltage detection module 30 is electrically connected to the live line L and the control module 70 respectively, for detecting the voltage of the live line and sending it to the control module 70; the neutral line voltage detection module 20 is electrically connected to the neutral line N and the control module 70 respectively, for detecting the voltage of the neutral line voltage and sends it to the control module 70; the ground detection module 40 is electrically connected to the neutral line N, the live line L and the control module 70, respectively, for detecting the voltage of the ground line and sending it to the control module 70; the relay driving module 50 is electrically connected to the relay 60 and the control module 70, respectively, for driving the relay 60 to be turned on or off; the control module 70 is used to: when any one of the output abnormal signals of the neutral line voltage detection module 20, the live line voltage detection module 30 and the ground line detection module 40 exists, the relay driving module 50 drives the relay 60 to be turned off.

[0033] The power module 10 utilizes a high-voltage-resistant chip, for example, one with a voltage rating of 900V or higher, to ensure that the chip is not damaged at a flyback input voltage of 400V, thereby protecting the circuits and components. Furthermore, an overvoltage protection function can be added to the power chip. When the voltage exceeds a certain level (e.g., 400V), the chip automatically shuts down the internal MOS transistor to stop operation, thereby protecting the circuits and preventing overvoltage damage to the circuits and components.

[0034] The control module 70 is electrically connected to the zero-line voltage detection module 20, and is used to receive the zero-line voltage detected by the zero-line voltage detection module 20 and determine whether the zero-line voltage is abnormal. The method by which the control module 70 determines whether the zero-line voltage is abnormal can be: the control module determines whether the zero-line voltage is abnormal based on the level signal of the zero-line voltage detected by the received zero-line voltage detection module 20. For example, assuming that when the zero-line voltage signal is a high-level signal, it can be determined that the zero-line voltage is abnormal. Otherwise, it can be determined that the zero-line voltage is normal. In addition, it can also be set as follows: when the zero-line voltage is a low level, the zero-line voltage is determined to be abnormal, otherwise, it is normal. The specific setting can be based on actual conditions and is not specifically limited here.

[0035] The control module 70 is electrically connected to the live wire voltage detection module 30, and is used to receive the live wire voltage detected by the live wire voltage detection module 30, and determine whether the live wire voltage is abnormal. The method for the control module 70 to determine whether the live wire voltage is abnormal can be: the control module determines whether the live wire voltage is abnormal based on the level signal of the live wire voltage detected by the received live wire voltage detection module 30. For example, assuming that when the live wire voltage signal is a high-level signal, it can be determined that the live wire voltage is abnormal. Otherwise, it can be determined that the live wire voltage is normal. In addition, it can also be set as follows: when the live wire voltage is a low level, the live wire voltage is determined to be abnormal, otherwise, it is normal. The specific setting can be based on actual conditions and is not specifically limited here.

[0036] The control module 70 is electrically connected to the ground detection module 40 and is configured to receive the ground voltage detected by the ground detection module 40 and determine whether the ground voltage is abnormal (which can determine whether the ground connection is normal). The control module 70 can determine whether the ground voltage is abnormal by, for example, determining whether the ground voltage is abnormal based on the ground voltage level signal received from the ground detection module 40. For example, if the ground voltage signal is high, the ground voltage can be determined to be abnormal. Otherwise, the ground voltage can be determined to be normal. Alternatively, the ground voltage can be determined to be abnormal when the ground voltage is low, and otherwise normal. The specific configuration can be tailored to the actual situation and is not specifically limited here.

[0037] The control module 70 is also electrically connected to the relay driver module 50, which is in turn electrically connected to the relay 60. The control module 70 receives the neutral voltage, live voltage, and ground voltage in real time, and determines whether the neutral voltage, live voltage, and ground voltage are abnormal based on the received neutral voltage, live voltage, and ground voltage. When any of the neutral voltage, live voltage, and ground voltage is abnormal, the relay driver module 50 is controlled to drive the relay 60 to close, preventing safety issues such as device damage and circuit damage caused by overvoltage or incorrect insertion of the charging gun into the power source, thereby protecting the circuit and reducing losses and costs.

[0038] The control module 70 controls the relay driver module 50 to drive the relay 60 on or off in a manner such that, for example, the control module 70 controls the relay to be on when it outputs a high-level signal to the relay driver module 50, and controls the relay to be off when it outputs a low-level signal to the relay driver module 50. Alternatively, the control module 70 controls the relay to be on when it outputs a low-level signal to the relay driver module 50, and controls the relay to be on when it outputs a high-level signal to the relay driver module 50.

[0039] For example, the control module may be a microcontroller unit (MCU). For example, the MCU may be a control chip such as a single chip microcomputer, which may be configured according to actual conditions and is not specifically limited here.

[0040] The relay 60 may be a single-pole single-throw relay, a double-pole double-throw relay, a combination relay, etc., and may be configured according to actual conditions, and no specific limitation is given here.

[0041] The charging gun can be used to charge electrical devices such as vehicles, including electric vehicles, new energy vehicles, hybrid vehicles, and engineering vehicles.

[0042] In the technical solution of this embodiment, the implementation process of the charging gun detection and protection circuit is as follows: Figure 1 The charging gun detection and protection circuit includes: a power module 10, a neutral voltage detection module 20, a live voltage detection module 30, a ground detection module 40, a relay driver module 50, a relay 60, and a control module 70. For example, taking the charging gun charging a new energy vehicle as an example, when the charging gun is connected to a power source to charge the vehicle, and / or during the charging process, the live voltage detection module 30 detects the live voltage in real time and sends it to the control module 70. The neutral voltage detection module 20 detects the neutral voltage in real time and sends it to the control module 70. The ground detection module 40 detects the ground voltage in real time and sends it to the control module 70. The control module 70 receives the live voltage detected by the live voltage detection module 30 and determines whether the live voltage is abnormal. The control module 70 also receives the neutral voltage and determines whether the neutral voltage is abnormal. The control module 70 also receives the ground voltage and determines whether the ground voltage is abnormal. This allows for comprehensive detection of voltage anomalies in the charging gun and circuit fault detection. And when the control module 70 determines that there is an abnormality in any voltage of the neutral line voltage detection module 20, the live line voltage detection module 30, and the ground detection module 40, it controls the relay driving module 50 to control the relay 60 to close, thereby avoiding problems such as charging gun puncture, device damage, circuit damage, etc. caused by excessive voltage of the charging gun or incorrect plugging of the power supply, thereby protecting the charging gun, circuit electronic components, etc.

[0043] It should be noted that the embodiments of the present application can be used to detect in real time whether the circuit has overvoltage or incorrect insertion into the power supply during the process of the charging gun charging the charging device, and / or when the charging gun is plugged into the power supply to charge the charging device, and to protect the circuit, circuit components, etc. when a fault occurs.

[0044] Figure 2This is a schematic diagram of another charging gun detection and protection circuit provided in the embodiment of the present application. Based on the above embodiment, optionally, refer to Figure 2 The relay driving module 50 at least includes: a first driving unit 51, a second driving unit 52 and an anti-reverse unit 53; wherein the first driving unit 51 is electrically connected to the control module 70, the first end of the anti-reverse unit 53 and the first end of the relay 60, respectively, and the second driving unit 52 is electrically connected to the control module 70, the second end of the anti-reverse unit 53 and the second end of the relay 60, respectively; the control module 70 is used to output a first level signal to the first driving unit 51 and a second level signal to the second driving unit 52 when any one of the neutral line voltage detection module 20, the live line voltage detection module 30 and the ground line detection module 40 outputs an abnormal signal, so as to control the relay 60 to be closed.

[0045] For example, the first level signal may be a high level signal, and correspondingly, the second level signal may be a low level signal. Alternatively, the first level signal may be a low level signal, and correspondingly, the second level signal may be a high level signal. Specific settings may be made based on actual conditions and are not specifically limited herein.

[0046] The anti-reverse unit 53 may be an anti-reverse diode.

[0047] Specifically, the live line voltage detection module 30 detects the live line voltage in real time and sends it to the control module 70. The neutral line voltage detection module 20 detects the neutral line voltage in real time and sends it to the control module 70. The ground detection module 40 detects the ground line voltage in real time and sends it to the control module 70. The control module 70 receives the live line voltage detected by the live line voltage detection module 30 and determines whether the live line voltage is abnormal. The control module 70 receives the neutral line voltage and determines whether the neutral line voltage is abnormal. The control module 70 receives the ground voltage and determines whether the ground voltage is abnormal. If the control module 70 determines that any of the voltages in the neutral line voltage detection module 20, the live line voltage detection module 30, or the ground detection module 40 is abnormal, it outputs a first level signal to the first drive unit 51 and a second level signal to the second drive unit 52 to control the relay 60 to close. This prevents problems such as charging gun puncture, component damage, and circuit damage caused by overvoltage or incorrect insertion of the charging gun, thereby protecting the charging gun and electronic components.

[0048] Figure 3 This is a schematic diagram of the circuit structure of a relay drive module provided in an embodiment of the present application. Based on the above embodiment, optionally, refer to Figure 3The first driving unit at least includes: a first switching tube Q1, a second switching tube Q2 and a first resistor R1; wherein, the first end of the first switching tube Q1 is electrically connected to the control module 70 (for example, assuming that it is connected to the P1 terminal of the control module), the second end of the first switching tube Q1 is grounded, the third end of the first switching tube Q1 is electrically connected to the first end of the first resistor R1, the second end of the first resistor R1 is electrically connected to the first end of the second switching tube Q2, the second end of the second switching tube Q2 is electrically connected to the power supply terminal (for example, a +12V power supply), and the third end of the second switching tube Q2 is electrically connected to the first end of the relay and the first end of the anti-reverse unit respectively.

[0049] Exemplarily, the relay is a combination relay, that is, a first single-pole single-throw relay K1 and a second single-pole single-throw relay K2 connected in parallel.

[0050] Exemplarily, the anti-reverse unit is an anti-reverse diode D1 , the third end of the second switch tube Q2 is electrically connected to the cathode of the anti-reverse diode D1 , and the second end of the fourth switch tube Q4 is electrically connected to the anode of the anti-reverse diode D1 .

[0051] In addition, continue to see Figure 3 The first driving unit further includes: a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a first capacitor C1. The third resistor R3, the fourth resistor R4 and the fifth resistor R5 are used for voltage division and current limiting, and the first capacitor C1 is used for filtering.

[0052] Optionally, continue to Figure 3 The second driving unit at least includes: a third switch tube Q3, a fourth switch tube Q4, and a second resistor R2; wherein a first end of the third switch tube Q3 is electrically connected to the control module 70 (for example, assuming that it is connected to the P2 terminal of the control module), a second end of the third switch tube Q3 is electrically connected to the power supply terminal (for example, a +12V power supply), a third end of the third switch tube Q3 is electrically connected to the first end of the second resistor R2, a second end of the second resistor R2 is electrically connected to the first end of the fourth switch tube Q4, a second end of the fourth switch tube Q4 is electrically connected to the second end of the relay and the second end of the anti-reverse unit respectively, and a third end of the fourth switch tube Q4 is grounded.

[0053] In addition, continue to see Figure 3 The second driving unit further includes: a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a second capacitor C2. The sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are used for voltage division and current limiting, and the second capacitor C2 is used for filtering.

[0054] For example, the first switch tube Q1 , the second switch tube Q2 , the third switch tube Q3 and the fourth switch tube Q4 may be triodes or MOS tubes, etc., and may be configured according to actual conditions, and are not specifically limited here.

[0055] For example, using transistors as the switching transistors, the first switching transistor Q1 and the fourth switching transistor Q4 are NPN transistors, and the second switching transistor Q2 and the third switching transistor Q3 are PNP transistors. It should be noted that whether the switching transistors are NPN or PNP depends on the actual circuit structure and function and can be set according to actual circumstances as long as they can achieve the driving of the relay of the present application. This is not specifically limited here.

[0056] For example, see Figure 3 Taking the example of the first and fourth switches Q1 and Q4 being NPN transistors, and the second and third switches Q2 and Q3 being PNP transistors, the operating principles of the first and second drive units are as follows: when the control module outputs a high-level signal at terminal P1 and a low-level signal at terminal P2, since the first switch Q1 is an NPN transistor, the high-level signal output from terminal P1 turns on the first switch Q1. This turns on the voltage at the first terminal of the second switch Q2, which in turn turns on the second switch Q2, which in turn turns on the second switch Q2, which in turn turns on the third switch Q3, which in turn turns on the third switch Q3, which in turn turns on the fourth switch Q4, which in turn turns on the fourth switch Q4, which in turn turns on the fourth switch Q4, which in turn turns on the fourth switch Q4, which in turn turns on the fourth switch Q4. This turns on the relay.

[0057] Similarly, when the control module's P1 terminal outputs a low-level signal and P2 terminal outputs a high-level signal, the low-level signal output from P1 disables the first switch Q1 because it is an NPN type. Simultaneously, the high-level signal output from P2 disables the third switch Q3 because it is a PNP type, thus preventing the relay from turning on.

[0058] Optionally, refer again to Figure 2 The live wire voltage detection module 30 includes at least: a first voltage dividing unit 31, a first amplifying unit 32 and a first pull-up unit 33; wherein the first voltage dividing unit 31 is electrically connected to the live wire L and the first amplifying unit 32 respectively, the first amplifying unit 32 is electrically connected to the first pull-up unit 33, and the first pull-up unit 33 is also electrically connected to the control module 70.

[0059] Among them, the implementation process of the live wire voltage detection module is as follows: the AC voltage output by the power module is divided by the first voltage divider unit 31 to obtain a relatively small voltage value (here it is used to ensure that when the input voltage is high, the back-end circuit will not be damaged, thereby protecting the circuit and device). Then, it is amplified by a certain multiple by the first amplification unit 32 and output, and then after the first pull-up unit pulls up, the positive and negative voltage values of the AC voltage can be normally detected to meet the detection of the positive and negative AC voltages. Thus, the live wire voltage detection module can detect the live wire voltage and output it to the control module 70. The control module 70 receives the live wire voltage and determines whether it is abnormal, and controls the relay 60 to close when the live wire voltage is abnormal to protect the circuit.

[0060] Figure 4 This is a circuit diagram of a live wire voltage detection module provided in an embodiment of the present application. Based on the above embodiment, optionally, refer to Figure 4 The first voltage divider unit includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12. The first amplifying unit includes a first operational amplifier U1, a fourteenth resistor R14, and a fifteenth resistor R15. The first pull-up unit includes a first pull-up resistor RL1 and a second pull-up resistor RL2.

[0061] Among them, the implementation process of the live wire voltage detection module is as follows: through resistor voltage division, the 220V AC power supply is converted into a 5V AC voltage, and the voltage signal is amplified to a voltage of 0-5V using an operational amplifier, the live wire voltage is detected and output to the control module. Specifically, the AC voltage reaches the voltage divider resistor R12 through the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11, and reaches GND through the voltage divider resistor R12. The voltage divider resistor R12 obtains a relatively small voltage value (here used to ensure that the back-end circuit will not be damaged when the input voltage is high, thereby protecting the circuit and device). Then, it is amplified by a certain multiple by the first operational amplifier U1 and output, and then pulled up by the first pull-up resistor RL1 and the second pull-up resistor RL2, giving the voltage output value a 2.5V superposition, so that the positive and negative voltage values of the AC voltage can be normally detected to meet the detection of the AC ±400V voltage. Thus, the live wire voltage detection module can detect the live wire voltage and output it to the live wire voltage detection terminal VP10 of the control module 70. The control module 70 receives the live wire voltage, calculates the actual voltage of the live wire by multiplying the detected live wire voltage value by the corresponding multiple through software, and determines whether it is abnormal. When the live wire voltage is abnormal, it controls the relay 60 to close to protect the circuit.

[0062] The voltage divider value of the voltage divider resistor R12 is the ratio of the input voltage Vin multiplied by the resistance value of R12. The voltage divider calculation formula of the voltage divider resistor R12 is:

[0063] VR12=Vin*R12 / (R9+R10+R11+R12)

[0064] For example, when the input voltage Vin is 220V, and the resistance values of the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11 are all 100 kilo-ohms, and the resistance value of the voltage-dividing resistor R12 is 392 ohms, the voltage-dividing value of the voltage-dividing resistor R12 is: VR12 = 220*392 / (100000+100000+100000+392) = 0.287V.

[0065] The amplification factor of the first operational amplifier U1 is related to the resistance values of the fourteenth resistor R14 and the fifteenth resistor R15. The specific setting can be based on actual conditions and will not be detailed here. For example, assuming that the resistance values of the fourteenth resistor R14 and the fifteenth resistor R15 are 10 ohms and 49.9 ohms, respectively, the amplification factor is: R15 / R14=49.9 / 10=4.99 times.

[0066] In addition, continue to see Figure 4 The live line voltage detection module further includes a thirteenth resistor R13, a first inductor E1, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6 and a second diode D2.

[0067] Optionally, refer again to Figure 2 The neutral line voltage detection module 20 includes at least: a second voltage dividing unit 21, a second amplifying unit 22 and a second pull-up unit 23; wherein the second voltage dividing unit 21 is electrically connected to the neutral line N and the second amplifying unit 22 respectively, the second amplifying unit 22 is electrically connected to the second pull-up unit 23, and the second pull-up unit 23 is also electrically connected to the control module 70.

[0068] The implementation process of the zero-line voltage detection module is as follows: the AC voltage output by the power module is divided by the second voltage divider unit 21 to obtain a relatively small voltage value (here used to ensure that when the input voltage is high, the back-end circuit will not be damaged, thereby protecting the circuit and device). Then, it is amplified by a certain multiple by the second amplification unit 22 and output. After being pulled up by the second pull-up unit, the positive and negative voltage values of the AC voltage can be normally detected to meet the detection of the positive and negative AC voltages. In this way, the zero-line voltage detection module can detect the zero-line voltage and output it to the control module 70. The control module 70 receives the zero-line voltage and determines whether it is abnormal. When the zero-line voltage is abnormal, it controls the relay 60 to close to protect the circuit.

[0069] Figure 5 This is a circuit diagram of a zero-line voltage detection module provided in an embodiment of the present application. Based on the above embodiment, optionally, refer to Figure 5The second voltage divider unit includes a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, and a nineteenth resistor R19. The second amplifying unit includes a second operational amplifier U2, a twenty-first resistor R21, and a twenty-second resistor R22. The second pull-up unit includes a third pull-up resistor RL3 and a fourth pull-up resistor RL4.

[0070] Among them, the implementation process of the zero-line voltage detection module is as follows: through resistor voltage division, the 220V AC power supply is converted to a 5V AC voltage, and the voltage signal is amplified to a voltage of 0-5V using an operational amplifier, the zero-line voltage is detected and output to the control module. Specifically, the AC voltage reaches the voltage divider resistor R19 through the sixteenth resistor R16, the seventeenth resistor R17, and the eighteenth resistor R18, and reaches GND through the voltage divider resistor R19. The voltage divider resistor R19 obtains a relatively small voltage value (here used to ensure that the back-end circuit will not be damaged when the input voltage is high, thereby protecting the circuit and device). Then, it is amplified by a certain multiple by the second operational amplifier U2 and output, and then pulled up by the third pull-up resistor RL3 and the fourth pull-up resistor RL4, giving the voltage output value a 2.5V superposition, so that the positive and negative voltage values of the AC voltage can be normally detected to meet the detection of the AC ±400V voltage. Thus, the zero-line voltage detection module can detect the zero-line voltage and output it to the VP20 terminal of the control module 70. The control module 70 receives the neutral voltage, calculates the actual voltage of the neutral line by multiplying the detected neutral voltage value by the corresponding multiple through software, and determines whether it is abnormal. When the neutral voltage is abnormal, it controls the relay 60 to close to protect the circuit.

[0071] The voltage divider value of the voltage divider resistor R19 is the ratio of the input voltage Vin multiplied by the resistance value of R19. The voltage divider calculation formula of the voltage divider resistor R19 is:

[0072] VR19=Vin*R19 / (R16+R17+R18+R19)

[0073] The amplification factor of the second operational amplifier U2 is related to the resistance setting of the twenty-first resistor R21 and the twenty-second resistor R22, which can be set according to actual conditions and will not be explained in detail here.

[0074] In addition, continue to see Figure 5 The neutral voltage detection module further includes a twentieth resistor R20, a second inductor E2, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10 and a third diode D3.

[0075] Optionally, refer again to Figure 2The grounding detection module at least includes: a third voltage dividing unit 41 and a third amplifying unit 42 , the third voltage dividing unit 41 is electrically connected to the live wire L, the neutral wire N and the third amplifying unit 42 respectively, and the third amplifying unit 42 is electrically connected to the control module 70 .

[0076] The ground detection module is used to simultaneously detect the neutral and live wire voltages relative to ground, and subtracts the neutral-to-ground and live-to-ground voltages to obtain the voltage between the neutral and live wires at the same point in time. The principle of ground voltage detection is to detect the voltage of the third voltage divider. When the voltage obtained by the third voltage divider is large, it indicates that the grounding of the ground wire (PE) is normal. When the voltage obtained by the third voltage divider is small, it indicates that the ground wire (PE) is not grounded. The current in the third voltage divider flows back to the detection circuit through the floating ground, thereby determining whether the grounding is normal.

[0077] Figure 6 This is a circuit diagram of a ground detection module provided in an embodiment of the present application. Based on the above embodiment, optionally, refer to Figure 6 The third voltage dividing unit includes a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-seventh resistor R27, and a twenty-eighth resistor R28. The third amplifying unit includes a third operational amplifier U3.

[0078] Specifically, the neutral and live wire voltages to ground are detected simultaneously, and the neutral-to-ground voltage and the live-to-ground voltage are subtracted to obtain the voltage between the neutral and live wires at the same point in time. The ground voltage detection principle is as follows: the voltage across the voltage divider resistor R28 is detected. When the voltage across the voltage divider resistor R28 is large, it indicates that the ground wire PE is properly grounded. When the voltage across the voltage divider resistor R28 is small, it indicates that the ground wire PE is not grounded. At this time, the current in the voltage divider resistor R28 flows back through the floating ground to the neutral and live wire voltage detection circuit, thereby determining whether the ground wire PE is properly grounded.

[0079] For example, the voltage VLN between the neutral line and the live line at the same time point is calculated by software as follows: Assuming that the sampling period is 20ms and the number of sampling points in each sampling period is 80, the voltage VLN is calculated using the root mean square value as follows:

[0080]

[0081] Among them, VL1, VL2, ..., VL80 are 80 sampling point values of the live wire to ground voltage, and VN1, VN2, ..., VN80 are 80 sampling point values of the neutral wire to ground voltage.

[0082] Figure 7This is a schematic diagram of the structure of the first half cycle of an alternating current provided in an embodiment of the present application. For example, the voltage of the live wire L to the ground is detected in the first half cycle of the alternating current, and the detection method is:

[0083] VPE=VL*R28 / (R23+R24+R27+R28)=220V*15 / (100+100+200+15)=VL / 27.6, where VPE is the voltage to ground and VL is the live line voltage.

[0084] Different regions have different requirements for neutral and live voltages. For example, in some regions, the neutral voltage (N) to ground is measured during the negative half-cycle of the AC power supply, and is normally between 0 and 5V. In other regions, the neutral voltage and the live voltage are the same, meaning VN = VL.

[0085] See Figure 7 , Vm is the half-peak waveform average value, and Vdc is the DC voltage value.

[0086] in,

[0087] V dc =V m *1 / T∫(0,T / 2)sinθdθ

[0088] Among them, T=2π, T / 2=π, V m =220V, substituting into the above formula, we can get:

[0089] V dc =V m ×(1 / 2π)∫(0,π)sinθdθ

[0090] =(V m / 2π)×(-cosθ)|(0,π)

[0091] =(V m / 2π)×(1+1)

[0092] =V m / π=0.318V m

[0093] V dc =220V*0.318=98.9V

[0094] The voltage V at the input of the third operational amplifier U3 is V dc / 27.6=3.58V.

[0095] Figure 8 This is a schematic diagram of the current flow when the ground is abnormal provided in the embodiment of the present application. Figure 8If the grounding is abnormal, or the ground wire PE is floating, the voltage loop will no longer return to GND through the grounding point (GND is a floating point). For example, see Figure 8 The current of the voltage detection circuit of the live wire L flows through the common ground, and then flows back to the neutral wire N through the neutral wire loop of the LN voltage detection circuit. Figure 8 The dotted line L2 shows the current in the neutral line N voltage detection circuit. The current flows through the common ground and then back to the live line L through the live line loop of the LN voltage detection circuit. The voltage passes through diode D4 and resistors R23, R24, and R27 to the common ground line. Because the ground line is floating or abnormal, the current flows through the common ground point to R19 and then to VP2. VP2 then flows back to the neutral line N through R18, R17, R16, and E2. At this time, the voltage drop detected on resistor R19 is much smaller than the voltage detection when the ground line is not connected normally:

[0096] Among them, Vm=220V.

[0097] VPE=VL*R28 / (R23+R24+R27+R28+R12+R9+R10+R11)

[0098] =VL*15 / (100+100+200+15+100+100+100+0.392)

[0099] =VL*15 / 715.392=VL / 47.69

[0100] Vdc=220V*0.318=98.9V

[0101] When the ground line is not connected, the voltage V at the input port of the third operational amplifier U3 is Vdc / 47.69=2.07V.

[0102] When the input voltage is 220V AC, the voltage when the ground wire is normally grounded is 3.58V, and the voltage when it is not grounded is 2.07V. The voltage difference between the two is: 1.51V. Select the middle value.

[0103] For example, considering that the input voltage range is 85V to 265V, the grounded voltage and the ungrounded voltage are calculated using the formula. To determine whether to ground, an intermediate value is selected. The reference ranges for the input voltage, grounded voltage, and ungrounded voltage are shown in Table 1. The unit in Table 1 is V.

[0104] Table 1 Voltage reference range

[0105] Input voltage V Ground detection voltage V Ungrounded voltage V Threshold value V 70 0.807717161 0.467456356 0.637586758 80 0.923105326 0.534235836 0.728670581 90 1.038493492 0.601015315 0.819754404 100 1.153881658 0.667794795 0.910838226 110 1.269269824 0.734574274 1.001922049 120 1.384657989 0.801353754 1.093005872 130 1.500046155 0.868133233 1.184089694 140 1.615434321 0.934912713 1.275173517 150 1.730822487 1.001692192 1.366257339 160 1.846210653 1.068471671 1.457341162 170 1.961598818 1.135251151 1.548424985 180 2.076986984 1.20203063 1.639508807 190 2.19237515 1.26881011 1.73059263 200 2.307763316 1.335589589 1.821676453 210 2.423151482 1.402369069 1.912760275 220 2.538539647 1.469148548 2.003844098 230 2.653927813 1.535928028 2.09492792 240 2.769315979 1.602707507 2.186011743 250 2.884704145 1.669486987 2.277095566 260 3.000092311 1.736266466 2.368179388 270 3.115480476 1.803045946 2.459263211 280 3.230868642 1.869825425 2.550347034 290 3.346256808 1.936604905 2.641430856 300 3.461644974 2.003384384 2.732514679

[0106] Figure 9 This is a schematic diagram of a fitting curve provided in the embodiment of the present application. The fitting curve obtained based on the data in Table 1 can be found in Figure 9 , including the ground detection voltage fitting curve M1, the non-ground voltage fitting curve M2 and the threshold value fitting curve M3. The fitting curve formula is:

[0107] Y=0.0091x-3e -15

[0108] Where x is the LN voltage, and Y is the PE voltage detected by the control module. Therefore, the circuit needs to detect both the LN and PE voltages. Once the LN voltage is confirmed, it is compared with the PE voltage. If it is below the threshold, the PE is open; if it is above the threshold, the PE is shorted.

[0109] Figure 10 This is a schematic diagram of another charging gun detection and protection circuit provided in the embodiment of the present application. Based on the above embodiment, optionally, refer to Figure 10 The charging gun detection and protection circuit also includes a relay detection module 80, which is electrically connected to the live wire L, the neutral wire N, the relay 60 and the control module 70 respectively, and is used to detect the on or off state of the relay 60.

[0110] Optionally, continue to Figure 10 The charging gun detection and protection circuit also includes a temperature detection module 100, a leakage detection module 110 and an alarm module 120; wherein, the temperature detection module 100 is arranged on the side of the relay 60 and is electrically connected to the control module 70; the leakage detection module 110 is electrically connected to the live wire L, the neutral wire N and the control module 70 respectively; the alarm module 120 is electrically connected to the control module 70.

[0111] Among them, the temperature detection module 100 is used to detect the temperature information of the circuit in real time and send it to the control module 70. The control module 70 determines whether it exceeds the preset temperature based on the received temperature information, and controls the relay 60 to be closed by driving the relay driving module when the preset temperature is exceeded, so as to protect the circuit and avoid overheating to damage the circuit and devices.

[0112] Exemplarily, the temperature detection module can use a thermistor, such as a negative temperature coefficient thermistor (NTC). The resistance of the NTC changes with temperature, and its corresponding voltage divider also changes accordingly. The voltage divider value is sent to the control module to determine whether the detected temperature is overheated or other abnormalities.

[0113] For example, considering that the relay is the component with the highest heat generation in the charging gun, the temperature detection module 100 can be arranged around the relay to monitor the temperature of the relay.

[0114] The leakage detection module 110 is used to detect the current of the circuit in real time and send it to the control module to detect whether the circuit has leakage. For example, if the current monitored in real time is less than the preset current, it can be determined that the circuit has leakage. In addition, other judgment conditions can be set according to actual conditions and are not specifically limited here. The leakage detection module 110 can be a Hall current sensor, which is used to transmit the small leakage current to the operational amplifier, and output it to the control module after amplification by the operational amplifier, and the control module determines whether leakage has occurred.

[0115] The alarm module 120 can be a light alarm. For example, if the control module detects an abnormality in any of the live voltage detection module, neutral voltage detection module, ground detection module, temperature detection module, or leakage detection module, it can activate a switch to illuminate an LED light, thereby providing an alarm. Furthermore, the alarm module can be an audible alarm, an audible and visual alarm, or other device. The specific configuration can be tailored to the specific situation and is not specifically limited here.

[0116] As an embodiment, optionally, the control module can be used to drive the relay driving module to control the relay to close when any abnormality occurs in any of the live line voltage detection module, the neutral line voltage detection module, the ground detection module, the temperature detection module and the leakage detection module, thereby protecting the circuit and avoiding damage to the charging gun, circuits and devices due to circuit failure or abnormality.

[0117] Optionally, continue to Figure 10 The charging gun detection and protection circuit also includes a surge protection module 90. The first end of the surge protection module 90 is electrically connected to the ground wire PE, the second end of the surge protection module 90 is electrically connected to the live wire L, and the third end of the surge protection module 90 is electrically connected to the neutral wire N. The surge protection module 90 is used to protect the circuit when a surge occurs.

[0118] Among them, by setting up a surge protection module, circuits and devices can be protected when a lightning surge occurs, reducing damage to the circuits and devices caused by lightning.

[0119] Figure 11 This is a schematic diagram of another charging gun detection and protection circuit provided in the embodiment of the present application. Based on the above embodiment, optionally, refer to Figure 11The surge protection module 90 at least includes: a gas discharge tube G1, a fuse F1, a first varistor MOV1, a second varistor MOV2, a first thermistor PTC1, and a second thermistor PTC2; wherein the gas discharge tube G1 is electrically connected to the ground wire PE and the fuse F1, respectively; the fuse F1 is electrically connected to the first end of the first thermistor PTC1 and the first end of the second thermistor PTC2, respectively; the second end of the first thermistor PTC1 is electrically connected to the first end of the first varistor MOV1, the second end of the first varistor MOV1 is electrically connected to the live wire L, the second end of the second thermistor PTC2 is electrically connected to the first end of the second varistor PTC2, and the second end of the second varistor PTC2 is electrically connected to the neutral wire N.

[0120] Usually, when the power grid is unstable, overvoltage and undervoltage are likely to occur. When overvoltage and undervoltage occur, the varistor of the existing surge protection circuit is easily broken down and burned, and even if it is replaced with a high-voltage varistor (such as a 420V varistor), it cannot be avoided. For this reason, refer to Figure 11 , the surge protection module provided in the embodiment of the present application includes a gas discharge tube G1, a fuse F1, a first varistor MOV1, a second varistor MOV2, a first thermistor PTC1 and a second thermistor PTC2. If a surge breakdown occurs, the varistor and the gas discharge tube G1 will be turned on at the same time, releasing the large voltage surge of the system. If the surge is over, the varistor and the gas discharge tube G1 will be disconnected. If the varistor and the gas discharge tube G1 fail to turn on, the temperature in the circuit will rise sharply. At this time, the resistance of the first thermistor PTC1 will increase, thereby preventing the circuit from burning due to the increase in current and temperature. In addition, when the circuit is quickly short-circuited and the increase in the resistance of PTC1 cannot protect the circuit (for example, when the current in the circuit is too large), the fuse F1 can be blown to protect the circuit from burning.

[0121] Optionally, continue to Figure 11 The relay detection module at least includes: a first isolation and signal transmission unit 81 and a second isolation and signal transmission unit 82; wherein, the first end of the first isolation and signal transmission unit 81 is electrically connected to the live wire L and the relay 60 respectively, the second end of the first isolation and signal transmission unit 81 is electrically connected to the neutral wire N and the live wire output terminal L0 respectively, the third end of the first isolation and signal transmission unit 81 is electrically connected to the control module 70, and the fourth end of the first isolation and signal transmission unit 81 is grounded; the first end of the second isolation and signal transmission unit 82 is electrically connected to the neutral wire N and the relay 60 respectively, the second end of the second isolation and signal transmission unit 82 is electrically connected to the live wire L and the neutral wire output terminal N0 respectively, the third end of the second isolation and signal transmission unit 82 is electrically connected to the control module 70, and the fourth end of the second isolation and signal transmission unit 82 is grounded.

[0122] Figure 12 This is a schematic diagram of the circuit structure of a relay detection module provided in an embodiment of the present application. Based on the above embodiment, optionally, refer to Figure 12 The first isolation and signal transmission unit includes a first optocoupler U4, the first end of which is electrically connected to the live wire L and the second relay K2, the second end of which is electrically connected to the live wire output terminal L0 and the neutral wire N, the third end of which is the output terminal Vi1 and is electrically connected to the control module, and the fourth end of which is grounded. The second isolation and signal transmission unit includes a second optocoupler U5, the first end of which is electrically connected to the neutral wire N and the first relay K1, the second end of which is electrically connected to the live wire L and the neutral wire output terminal N0, the third end of which is the output terminal Vi2 and is electrically connected to the control module 70, and the fourth end of which is grounded. Figure 12 The relay detection module also includes: a sixth diode D6, a seventh diode D7, an eighth diode D8, a ninth diode D9, a tenth diode D10, an eleventh diode D11, a twelfth diode D12, a thirteenth diode D13, a fourteenth diode D14, a fifteenth diode D15, a thirty-third resistor R33, a thirty-fourth resistor R34, a thirty-fifth resistor R35, a thirty-sixth resistor R36, a thirty-seventh resistor R37, a thirty-eighth resistor R38, a thirty-ninth resistor R39, a fortieth resistor R40, a forty-first resistor R41, a forty-second resistor R42, and a fourteenth capacitor C14 and a fifteenth capacitor C15.

[0123] The relay detection module operates as follows: Before the first relay K1 and the second relay K2 close, the live line voltage passes through the sixth diode D6, the seventh diode D7, the first optocoupler U4, the thirty-third resistor R33, the thirty-fourth resistor R34, the thirty-fifth resistor R35, and the thirty-sixth resistor R36 in sequence before returning to the neutral line. When the live line voltage passes through the first optocoupler U4, it drives the output terminal Vi1 of the first optocoupler U4 to conduct. Vi1 generates a duty cycle signal in response to the alternating current and outputs it to the control module, which then reads the duty cycle signal.

[0124] Figure 13 This is a schematic diagram of a signal output from the first optocoupler output terminal before the relay is closed, as provided in an embodiment of the present application. Figure 13 , showing that the first optocoupler output terminal outputs a duty cycle signal before the relay is closed.

[0125] When the control module drives the first relay K1 and the second relay K2 to close, the voltage at the input end is equal to the voltage at the output end, and the tube voltage drops on the tenth diode D10 and the eleventh diode D11 at the output end are smaller than the tube voltage drops of the sixth diode D6, the seventh diode D7 and the first optocoupler U4 at the input end. Therefore, the live wire current returns to the neutral line N after passing through the sixth diode D6, the seventh diode D7 and the thirty-third resistor R33, the thirty-fourth resistor R34, the thirty-fifth resistor R35 and the thirty-sixth resistor R36, causing the first optocoupler U4 to be short-circuited. Therefore, the output end Vi1 of the first optocoupler U4 continuously outputs a high-level signal at this time.

[0126] Figure 14 This is a schematic diagram of a signal output from the first optocoupler output terminal after a relay is closed, as provided in an embodiment of the present application. Figure 14 , showing that the first optocoupler output terminal outputs a high-level signal after the relay is closed.

[0127] In addition, the power module may also include a filtering circuit, a switching power supply circuit, and a high-low voltage conversion circuit. Exemplarily, the filtering circuit may be an electromagnetic compatibility filter (EMC) filtering circuit, and the EMC filtering circuit is used to filter out the EMC interference of the power grid to the circuit to ensure that both the conducted radiation and the space radiation meet the EMC requirements, for example, mainly meet the radiation requirements of the CISPR25 and ECER10 standards. Among them, the EMC filtering circuit is composed of an X capacitor, a common-mode inductor, and a Y capacitor. Among them, it needs to be placed at the input line inlet of the port during layout and wiring. And the device withstand voltage value is greater than 450V to meet the application scenario where the overvoltage exceeds 450V and fails.

[0128] Figure 15 This is a schematic diagram of the structure of an EMC filter circuit provided in an embodiment of the present application. Figure 15 The EMC filter circuit includes a sixteenth capacitor C16, a common-mode inductor X0, a sixteenth capacitor C17, and a sixteenth capacitor C18. The X capacitor includes the sixteenth capacitor C16, and the Y capacitor consists of the sixteenth capacitors C17 and C18. Furthermore, the EMC filter circuit is equipped with an overtemperature protection fuse F2. At normal temperatures, the resistance of the overtemperature protection fuse F2 is very low. As the temperature rises, the resistance of the overtemperature protection fuse F2 increases. Therefore, when the back-end circuit is abnormal, the resistance of the overtemperature protection fuse F2 will also be very high, effectively limiting the current in the loop.

[0129] Figure 16 Schematic diagram of a switching power supply circuit provided in an embodiment of the present application. Figure 16The operating principle of the switching power supply circuit is as follows: 220V AC power passes through rectifier bridge D16, which rectifies the sinusoidal AC power into a positive half-wave waveform. This positive half-wave is then rectified into a DC circuit via capacitors C19 and C20 (both of which are electrolytic capacitors). Power supply chip U6 is a switching power supply chip with a built-in MOS transistor. The MOS transistor within power supply chip U6 switches at a frequency of 90kHz, charging and discharging the primary winding of transformer T1. When the MOS transistor is on, energy is stored in transformer T1 at pins 6, 7, 8, and 10 on the secondary side of the output of transformer T1. When the MOS transistor is off, the output of transformer T1 releases voltage, which is rectified into a +12V output by diode D17 and capacitor C21, and then into a -12V output by diode D18 and capacitor C22. Capacitor C23 and resistor R43 absorb the peak value of the ringing signal generated by the high-frequency switching of the +12V voltage. The twenty-fourth capacitor C24 and the thirty-forty-fourth resistor R44 are used to absorb the peak value of the ringing signal generated when the +12V high frequency is switched.

[0130] The 12V voltage is divided down to 2.5V by the forty-fifth resistor R45, the forty-sixth resistor R46, and the forty-seventh resistor R47, and then fed to the voltage regulator chip U7. When the output voltage is greater than 12V, the divided voltage value is also greater than 2.5V. The input current of the third optocoupler U8 is very low, the output current is also very low, and the current value detected by the feedback terminal FB of the voltage regulator chip U7 is also very low. The PWM duty cycle is internally adjusted to a small output. When the voltage is lower than 12V and the voltage divided voltage value is less than 2.5V, the input current of the third optocoupler U8 increases, the output current also increases, the current value detected by the feedback terminal FB of the voltage regulator chip U7 is also large, and the PWM duty cycle is internally adjusted to a large output. This ensures that the output is consistently stable at around 12V.

[0131] Among them, the high voltage resistance of 900V is achieved by adopting a high-voltage power supply chip, and it has a high-voltage overvoltage shutdown function.

[0132] The overvoltage protection VPRO value of pin 5 PRO of U8-6 is 3.1 (+ / - 0.2) V, and the overvoltage protection range Vin is:

[0133] VPRO*(R208-49+R223-52+R224-51+R225-50+R202-48) / R202-48, the input protection voltage action range is 389.6VDC to 443VDC, and the corresponding AC value is 275.6V to 313.3V.

[0134] Exemplarily, the high-low voltage conversion circuit is used to convert the 12V voltage into a 5V voltage internally for providing 5V power supply. Exemplarily, the 12V can be converted into a 5V voltage by a linear voltage regulator (Low Dropout Regulator, LDO) to power the control module. Since the power supply requirement of 5V is relatively low, usually around 100mA, the LDO can meet the requirement. Among them, the maximum power consumption of the LDO is (12-5)V*0.1A=0.7W. Consider the heat dissipation area during layout. For example, if the high and low temperature test detects that the surface temperature rise of the LDO is within the required range, the total heat dissipation area on the front and back of the layout reaches 1cm 2 .

[0135] Correspondingly, an embodiment of the present application further provides a charging gun for use in a vehicle, and the charging gun includes the charging gun detection and protection circuit provided in any embodiment of the present application.

[0136] Among them, the charging gun can be used for charging automobiles, new energy vehicles, engineering vehicles, electrical equipment and tools, etc., and can be specifically set according to actual conditions, and no specific restrictions are made here.

[0137] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0138] The above is a detailed introduction to the charging gun detection and protection circuit provided in the embodiments of the present application, and specific examples are used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A charging gun detection and protection circuit, characterized in that: include: Power supply module, neutral voltage detection module, live voltage detection module, ground detection module, relay drive module and relay; Wherein, the power supply module includes a live wire, a neutral wire and a ground wire; the live wire voltage detection module is electrically connected to the live wire and coupled to the relay drive module for detecting the voltage of the live wire; The neutral line voltage detection module is electrically connected to the neutral line and coupled to the relay driving module, and is used to detect the voltage of the neutral line; The ground detection module is electrically connected to the neutral wire and the live wire respectively, and is coupled to the relay driving module, for detecting the voltage of the ground wire; The relay driving module is electrically connected to the relay and is used to drive the relay to be turned on or off.

2. The charging gun detection and protection circuit according to claim 1, characterized in that: The relay driving module includes at least: a first driving unit, a second driving unit and an anti-reverse unit; wherein the first driving unit is electrically connected to the first end of the anti-reverse unit and the first end of the relay, respectively, and the second driving unit is electrically connected to the second end of the anti-reverse unit and the second end of the relay, respectively.

3. The charging gun detection and protection circuit according to claim 2, characterized in that: The first driving unit includes at least: a first switching tube, a second switching tube and a first resistor; wherein, the first end of the first switching tube receives a first driving signal, the second end of the first switching tube is grounded, the third end of the first switching tube is electrically connected to the first end of the first resistor, the second end of the first resistor is electrically connected to the first end of the second switching tube, the second end of the second switching tube is electrically connected to the power supply end, and the third end of the second switching tube is electrically connected to the first end of the relay and the first end of the anti-reverse unit respectively.

4. The charging gun detection and protection circuit according to claim 2, characterized in that: The second driving unit at least includes: a third switching tube, a fourth switching tube and a second resistor; wherein, the first end of the third switching tube receives the second driving signal, the second end of the third switching tube is electrically connected to the power supply end, the third end of the third switching tube is electrically connected to the first end of the second resistor, the second end of the second resistor is electrically connected to the first end of the fourth switching tube, the second end of the fourth switching tube is electrically connected to the second end of the relay and the second end of the anti-reverse unit respectively, and the third end of the fourth switching tube is grounded.

5. The charging gun detection and protection circuit according to claim 1, characterized in that: The live wire voltage detection module includes at least: a first voltage dividing unit, a first amplifying unit and a first pull-up unit; wherein, the first voltage dividing unit is electrically connected to the live wire and the first amplifying unit respectively, the first amplifying unit is electrically connected to the first pull-up unit, and the first pull-up unit is also coupled to the relay driving module.

6. The charging gun detection and protection circuit according to claim 1, characterized in that: The neutral line voltage detection module includes at least: a second voltage dividing unit, a second amplifying unit and a second pull-up unit; wherein, the second voltage dividing unit is electrically connected to the neutral line and the second amplifying unit respectively, the second amplifying unit is electrically connected to the second pull-up unit, and the second pull-up unit is also coupled to the relay driving module.

7. The charging gun detection and protection circuit according to claim 1, characterized in that: The grounding detection module at least includes: a third voltage dividing unit and a third amplifying unit. The third voltage dividing unit is electrically connected to the live wire, the neutral wire and the third amplifying unit respectively. The third amplifying unit is coupled to the relay driving module.

8. The charging gun detection and protection circuit according to claim 1, characterized in that: It also includes a relay detection module, which is electrically connected to the live wire, the neutral wire and the relay respectively, and is used to detect the on or off state of the relay.

9. The charging gun detection and protection circuit according to claim 8, characterized in that: The relay detection module includes at least: a first isolation and signal transmission unit and a second isolation and signal transmission unit; wherein, the first end of the first isolation and signal transmission unit is electrically connected to the live wire and the relay respectively, the second end of the first isolation and signal transmission unit is electrically connected to the neutral wire and the live wire output end respectively, the third end of the first isolation and signal transmission unit is the first signal output end, and the fourth end of the first isolation and signal transmission unit is grounded; the first end of the second isolation and signal transmission unit is electrically connected to the neutral wire and the relay respectively, the second end of the second isolation and signal transmission unit is electrically connected to the live wire and the neutral wire output end respectively, the third end of the second isolation and signal transmission unit is the second signal output end, and the fourth end of the second isolation and signal transmission unit is grounded.

10. The charging gun detection and protection circuit according to claim 1, characterized in that: It also includes a surge protection module, a first end of the surge protection module is electrically connected to the ground wire, a second end of the surge protection module is electrically connected to the live wire, and a third end of the surge protection module is electrically connected to the neutral wire. The surge protection module is used to protect the circuit when a surge occurs.

11. The charging gun detection and protection circuit according to claim 10, characterized in that: The surge protection module at least includes: a gas discharge tube, a fuse, a first varistor, a second varistor, a first thermistor and a second thermistor; The gas discharge tube is electrically connected to the ground wire and the fuse, respectively; the fuse is electrically connected to the first end of the first thermistor and the first end of the second thermistor, respectively; the second end of the first thermistor is electrically connected to the first end of the first varistor, the second end of the first varistor is electrically connected to the live wire, the second end of the second thermistor is electrically connected to the first end of the second varistor, and the second end of the second varistor is electrically connected to the neutral wire.

12. The charging gun detection and protection circuit according to claim 1, characterized in that: It also includes a temperature detection module, a leakage detection module and an alarm module; wherein the temperature detection module is arranged on the relay side; the leakage detection module is electrically connected to the live wire and the neutral wire respectively; and the alarm module is used for alarming.

13. A charging gun, characterized in that: Applied to a vehicle, the charging gun includes the charging gun detection and protection circuit according to any one of claims 1 to 12.

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