Electric leakage detection circuit and charging pile

By designing a leakage detection circuit configured with the power switch driving circuit of the relay, the problem that traditional charging pile leakage detectors cannot effectively detect multiple leakage signals and cannot realize the hardware automatic disconnection of the relay is achieved, and efficient and safe leakage protection of the charging pile is achieved.

CN222762254UActive Publication Date: 2025-04-15HANGZHOU JIAWA NEW ENERGY TECH CO LTD
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Patent Information

Application Number
CN202420581370.8
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-03-25
Publication Date
2025-04-15
Estimated Expiration
2034-03-25

AI Technical Summary

Technical Problem

The leakage detector of traditional charging piles cannot effectively detect sudden or slowly rising sinusoidal AC signals, pulsating DC signals, and DC6mA signals leakage, and cannot automatically disconnect the relay from the hardware.

Method used

A leakage detection circuit is designed. By configuring a relay power switch driving circuit, connecting the leakage sensor and the relay, the relay switch is physically disconnected after the leakage signal is detected, achieving accurate and efficient leakage protection.

Benefits of technology

This design can effectively detect various types of leakage signals and realize the hardware automatic disconnection of relays to ensure the safety and reliability of charging piles.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

The utility model provides an electric leakage detection circuit and a charging pile. The electric leakage detection circuit comprises an electric leakage sensor; a main power relay; a relay driving circuit; a power switch control circuit; wherein an output pin of the electric leakage sensor is connected with an input end of the power switch control circuit, a detected live wire and a detected zero wire penetrate through an aperture of the electric leakage sensor, a switch contact of the main power relay is connected with the corresponding live wire and the corresponding zero wire, and the electric leakage sensor is used for sensing an electric leakage signal. The relay driving circuit is connected with the power switch control circuit and used for controlling the power switch control circuit to output signals, the output end of the power switch control circuit is connected with the relay driving circuit through a cooperative control triode, and the cooperative control triode is connected with the main power relay and used for controlling on-off of the main power relay.
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Description

Technical Field

[0001] The utility model relates to the technical field of leakage detection, in particular to a leakage detection circuit and a charging pile. Background Art

[0002] With the popularity of new energy vehicles, the safety of charging piles has received more and more attention. At present, the leakage detectors of traditional charging piles are generally AC type. However, AC type leakage detectors have the following technical defects: 1. They cannot guarantee effective action for leakage of suddenly applied or slowly rising sinusoidal AC signals, pulsating DC signals, and DC6mA signals. 2. After detecting the leakage signal, the software needs to control the power relay to disconnect and stop charging, and the hardware cannot be automatically disconnected. Utility Model Content

[0003] One of the utility model objects of the utility model is to provide a leakage detection circuit and a charging pile. The leakage detection circuit is configured with a relay power switch driving circuit, and the relay power switch driving circuit is connected to a leakage sensor and a relay. Through the structure of the utility model, the relay switch can be physically disconnected after the leakage signal is detected, thereby realizing accurate and efficient leakage protection.

[0004] Another utility model object of the utility model is to provide a leakage detection circuit and a charging pile. The leakage detection circuit has a relay adhesion detection circuit. The relay adhesion detection circuit can effectively detect whether the relevant contacts of the relay are adhered before charging, so as to avoid charging risks caused by adhesion of the relay contacts.

[0005] Another utility model object of the utility model is to provide a leakage detection circuit and a charging pile. The circuit structure of the leakage detection circuit can effectively take action on the leakage of suddenly applied or slowly rising sinusoidal AC signals, pulsating DC signals, and DC6mA signals, and is suitable for different standard requirements.

[0006] In order to achieve at least one of the above-mentioned utility model purposes, the utility model provides a leakage detection circuit, the leakage detection circuit comprising:

[0007] Leakage sensor;

[0008] Main power relay;

[0009] Relay drive circuit;

[0010] Power switch control circuit;

[0011] The output pin of the leakage sensor is connected to the input end of the power switch control circuit, the aperture of the leakage sensor penetrates the detected live wire and neutral wire, the main power relay switch contacts are connected to the corresponding live wire and neutral wire, the leakage sensor is used to sense the leakage signal and to control the output signal of the power switch control circuit, the output end of the power switch control circuit and the relay drive circuit are connected through a cooperative control transistor, and the cooperative control transistor is connected to the main power relay to control the switch of the main power relay.

[0012] According to one of the preferred embodiments of the utility model, the leakage detection circuit includes a voltage conversion circuit, wherein the voltage conversion circuit includes a diode D101, a resistor R101 and a resistor R100, wherein the cathode of the diode D101 is connected to the output pin I / O of the leakage sensor, and the anode of the diode D101 is respectively connected to one end of the resistor R101 and the resistor R100, the other end of the resistor R100 is connected to the conversion voltage power supply, and the other end of the resistor R101 is connected to the input end of the power switch control circuit.

[0013] According to another preferred embodiment of the utility model, the power switch control circuit includes: a resistor R107, a resistor R105, a transistor T100, a resistor R109, a resistor R112, a resistor R111, a transistor T101, a resistor R102, and a MOS tube Q100, wherein two ends of the resistor R107 are respectively connected to the resistor R101 and one end of the resistor R105, and the other end of the resistor R105 is connected to the power supply; the resistor R105 and the resistor R107 are connected to the base of the transistor T100, the emitter of the transistor T100 is connected to the other end of the resistor R105, the collector of the transistor T100 is connected to the resistor R109 and one end of the resistor R112, the other end of the resistor R109 is grounded, and the other end of the resistor R112 is connected to the base of the transistor T101.

[0014] According to another preferred embodiment of the utility model, the power switch control circuit includes: the base of the transistor T101 is also connected to one end of the resistor R111, the other end of the resistor R111 is grounded, the emitter of the transistor T101 is connected to the other end of the resistor R111, the collector of the transistor T101 is connected to the resistor R102, and the resistor R102 is respectively connected to the gate and source of the MOS tube Q100, the source of the MOS tube Q100 is connected to a power supply voltage, and the drain of the MOS tube Q100 is connected to the relay K100 and the cathode of the diode D100.

[0015] According to another preferred embodiment of the utility model, the relay drive circuit includes: a resistor R106, a resistor R113, and a cooperatively controlled transistor T102, wherein the collector of the cooperatively controlled transistor T102 is connected to the positive electrode of the diode D100, the two ends of the resistor R113 are respectively connected to the emitter and base of the cooperatively controlled transistor T102, and one end of the resistor R106 is connected to the base of the cooperatively controlled transistor T102, and the other end of the resistor R106 is connected to the relay drive power supply of the MCU for outputting a drive level signal.

[0016] According to another preferred embodiment of the utility model, the leakage detection circuit includes a relay adhesion detection circuit, and the relay adhesion detection circuit includes: resistor R103, resistor R108, diode D102, capacitor C103, resistor R104, wherein one end of the resistor R103 is connected to the power supply voltage, and the other end of the resistor R103 is connected to one end of the contact adhesion detection pin of the relay, and the other end of the contact adhesion detection pin is respectively connected to one end of the resistor R108, the diode D102, one end of the capacitor C103, and one end of the resistor R104, wherein the diode D102 is a TVS protection diode.

[0017] According to another preferred embodiment of the utility model, the relay adhesion detection circuit includes: the other end of the resistor R108 is grounded, the diode D102 and the capacitor C103 are connected in parallel, and the other end of the diode D102 is grounded, and the other end of the resistor R104 is connected to the MCU relay adhesion signal detection interface.

[0018] According to another preferred embodiment of the present invention, the source of the MOS tube Q100 is connected to a +12V RELAY voltage, and the cathode of the diode D100 is connected to a +12V voltage.

[0019] According to another preferred embodiment of the utility model, the output voltage of the leakage sensor in the voltage conversion circuit is +5V, and the conversion voltage is 3.3V.

[0020] In order to achieve at least one of the above-mentioned purposes of the utility model, the utility model provides a charging pile, and the charging pile is equipped with the above-mentioned leakage detection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shown is a schematic diagram of the structure of a leakage detection circuit of the present invention. DETAILED DESCRIPTION

[0022] The following description is used to disclose the utility model so that those skilled in the art can implement the utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the utility model defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the utility model.

[0023] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0024] Please combine Figure 1 The present invention discloses a leakage detection circuit and a charging pile, wherein the leakage detection circuit includes the following parts: a leakage sensor U100, a main power relay K100, a relay drive circuit and a power switch control circuit; wherein the leakage sensor U100 is installed near the live wire L and the neutral wire N of the charging pile, so that the live wire L and the neutral wire N can penetrate the leakage sensor aperture. The leakage sensor U100 is used to detect whether there is leakage in the live wire L and the neutral wire N of the charging pile. The live wire input terminal LWire_IN and the neutral wire input terminal NWire_IN are respectively connected to the corresponding contacts of the main power relay K100, and the live wire output terminal L_OUT and the neutral wire output terminal N_OUT are connected to the corresponding contacts of the main power relay K100. The output pin I / O of the leakage sensor U100 is connected to the input end of the power switch control circuit, and the output end of the power switch control circuit and the relay drive circuit are connected through a cooperative control transistor, and the cooperative control transistor is connected to the main power relay K100 to control the switch of the main power relay K100.

[0025] Specifically, the power switch control circuit of the present invention includes a resistor R107, a resistor R105, a transistor T100, a resistor R109, a resistor R112, a resistor R111, a transistor T101, a resistor R102, and a MOS tube Q100, wherein two ends of the resistor R107 are respectively connected to the resistor R101 and one end of the resistor R105, and the other end of the resistor R105 is connected to the power supply; the resistor R105 and the resistor R107 are connected to the base of the transistor T100, the emitter of the transistor T100 is connected to the other end of the resistor R105, the collector of the transistor T100 is connected to the resistor R109 and one end of the resistor R112, the other end of the resistor R109 is grounded, and the other end of the resistor R112 is connected to the base of the transistor T101. It should be noted that the power switch control circuit is connected to a voltage conversion circuit, wherein the voltage conversion circuit includes a diode D101, a resistor R101 and a resistor R100, wherein the cathode of the diode D101 is connected to the output pin I / O of the leakage sensor, and the anode of the diode D101 is connected to one end of the resistor R101 and one end of the resistor R100, respectively, the other end of the resistor R100 is connected to a conversion voltage power supply, and the other end of the resistor R101 is connected to the input end of the power switch control circuit. The voltage conversion circuit preferably converts the output voltage of the leakage sensor of +5V into a voltage of 3.3V and inputs it into the power switch control circuit, the resistor R100 is a pull-up resistor, and the resistor R101 is a current limiting resistor.

[0026] The power switch circuit structure also includes: the base of the transistor T101 is also connected to one end of the resistor R111, the other end of the resistor R111 is grounded, the emitter of the transistor T101 is connected to the other end of the resistor R111, the collector of the transistor T101 is connected to the resistor R102, and the resistor R102 is respectively connected to the gate and source of the MOS transistor Q100, the source of the MOS transistor Q100 is connected to a power supply voltage, and the drain of the MOS transistor Q100 is connected to the relay K100 and the cathode of the diode D100. The resistor R109, together with the resistor R111, the transistor T101, and the resistor R102, drives the D and S poles of the MOS transistor Q100 to turn on and off. The relay drive circuit includes: a resistor R106, a resistor R113, and a cooperative control transistor T102, wherein the collector of the cooperative control transistor T102 is connected to the positive electrode of the diode D100, the two ends of the resistor R113 are respectively connected to the emitter and the base of the cooperative control transistor T102, and one end of the resistor R106 is connected to the base of the cooperative control transistor T102, and the other end of the resistor R106 is connected to the relay drive power supply of the MCU for outputting a drive level signal, and the drive level signal and the signal generated by the conduction status of the D pole and the S pole of the MOS tube Q100 are used to drive the disconnection and closing of the related contacts of the relay, wherein the source of the MOS tube Q100 is connected to the RELAY voltage of +12V, and the cathode of the diode D100 is connected to the +12V voltage.

[0027] In order to improve the safety of the charging pile, the utility model further provides a relay adhesion detection circuit, the relay adhesion detection circuit includes: a resistor R103, a resistor R108, a diode D102, a capacitor C103, a resistor R104, wherein one end of the resistor R103 is connected to the power supply voltage, the other end of the resistor R103 is connected to one end of the contact adhesion detection pin of the relay, and the other end of the contact adhesion detection pin is respectively connected to one end of the resistor R108, the diode D102, one end of the capacitor C103, and one end of the resistor R104, wherein the diode D102 is a TVS protection diode. The other end of the resistor R108 is grounded, the diode D102 and the capacitor C103 are connected in parallel, and the other end of the diode D102 is grounded, and the other end of the resistor R104 is connected to the MCU relay adhesion signal detection interface.

[0028] In order to explain the technical effect of the above circuit structure, the present invention provides the following examples:

[0029] When there is no leakage in the charging pile, the output pin I / O of the leakage sensor U100 outputs a low level, and the output is low level after the level conversion of the diode D101, the pull-up resistor R100, and the current limiting resistor R101, and then connected to the resistor R107. Then the level of the resistor R105, the diode T100, and the resistor R112 is reversed to a high level, connected to the resistor R109, and the D and S poles of the MOS tube Q100 are driven together with the resistor R111, the transistor T101, and the resistor R102 to conduct, +12V and +12V_RELAY are connected together, and the relay coil is powered on. When the MCU applies OUT_MAINRELAY to a high level, R106, R113, and T102 drive the relay K100 to operate, the relay output contacts are closed, and the charging pile can be charged normally.

[0030] Before charging, the charging pile must detect whether the main power relay contacts are sticky. If so, charging is prohibited. When the relay K100 contacts are not sticky, pins 3 and 6 in the main power relay are short-circuited together, +3.3V is divided by resistors R103 and R108, diode D102 TVS protection, capacitor C103 filtering, resistor R104 current limiting, and MCU can detect the signal L1_N_Relay_FB high level. When the relay contacts are sticky, pins 3 and 6 in the main power relay are disconnected, and MCU detects the signal L1_N_Relay_FB low level.

[0031] In the case of leakage in the charging pile, including leakage of sinusoidal AC signal, pulsating DC signal, and DC6mA signal, the output pin I / O of the leakage sensor U100 outputs a +5V high level, which is converted to a +3.3V high level through a diode D101, a pull-up resistor R100, and a current limiting resistor R101, and then connected to resistor R107. Then the levels of resistor R105, transistor T100, and resistor R112 are inverted to a low level and connected to resistor R109. The MOS tube Q100 is driven together with resistor R111, transistor T101, and resistor R102, and the D pole is disconnected from the S pole, and +12V and +12V_RELAY are not connected. If the charging pile is charging the vehicle at this time, there is no need for software to drive the relay. After the relay coil loses power, the output contacts L_Wire_IN and L_OUT, N_Wire_IN and N_OUT will be disconnected immediately, realizing the hardware automatic disconnection of the main power relay, and charging stops, which is safe and reliable.

[0032] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the principles, the implementation methods of the present invention may be deformed or modified in any way.

Claims

1. A leakage detection circuit, characterized in that: The leakage detection circuit comprises: Leakage sensor; Main power relay; Relay drive circuit; Power switch control circuit; The output pin of the leakage sensor is connected to the input end of the power switch control circuit, the aperture of the leakage sensor penetrates the detected live wire and neutral wire, the main power relay switch contacts are connected to the corresponding live wire and neutral wire, the leakage sensor is used to sense the leakage signal and to control the output signal of the power switch control circuit, the output end of the power switch control circuit and the relay drive circuit are connected through a cooperative control transistor, and the cooperative control transistor is connected to the main power relay to control the switch of the main power relay.

2. A leakage detection circuit according to claim 1, characterized in that: The leakage detection circuit includes a voltage conversion circuit, wherein the voltage conversion circuit includes a diode D101, a resistor R101 and a resistor R100, wherein the cathode of the diode D101 is connected to the output pin I / O of the leakage sensor, and the anode of the diode D101 is respectively connected to one end of the resistor R101 and the resistor R100, the other end of the resistor R100 is connected to a conversion voltage power supply, and the other end of the resistor R101 is connected to the input end of the power switch control circuit.

3. A leakage detection circuit according to claim 1, characterized in that: The power switch control circuit includes: a resistor R107, a resistor R105, a transistor T100, a resistor R109, a resistor R112, a resistor R111, a transistor T101, a resistor R102, and a MOS tube Q100, wherein two ends of the resistor R107 are respectively connected to the resistor R101 and one end of the resistor R105, and the other end of the resistor R105 is connected to the power supply; the resistor R105 and the resistor R107 are connected to the base of the transistor T100, the emitter of the transistor T100 is connected to the other end of the resistor R105, the collector of the transistor T100 is connected to the resistor R109 and one end of the resistor R112, the other end of the resistor R109 is grounded, and the other end of the resistor R112 is connected to the base of the transistor T101.

4. A leakage detection circuit according to claim 3, characterized in that: The power switch control circuit includes: the base of the transistor T101 is also connected to one end of the resistor R111, the other end of the resistor R111 is grounded, the emitter of the transistor T101 is connected to the other end of the resistor R111, the collector of the transistor T101 is connected to the resistor R102, and the resistor R102 is respectively connected to the gate and source of the MOS tube Q100, the source of the MOS tube Q100 is connected to a power supply voltage, and the drain of the MOS tube Q100 is connected to the relay K100 and the cathode of the diode D100.

5. A leakage detection circuit according to claim 4, characterized in that: The relay drive circuit includes: a resistor R106, a resistor R113, and a cooperatively controlled transistor T102, wherein the collector of the cooperatively controlled transistor T102 is connected to the positive electrode of the diode D100, the two ends of the resistor R113 are respectively connected to the emitter and base of the cooperatively controlled transistor T102, and one end of the resistor R106 is connected to the base of the cooperatively controlled transistor T102, and the other end of the resistor R106 is connected to the relay drive power supply of the MCU for outputting a drive level signal.

6. A leakage detection circuit according to claim 1, characterized in that: The leakage detection circuit includes a relay adhesion detection circuit, and the relay adhesion detection circuit includes: a resistor R103, a resistor R108, a diode D102, a capacitor C103, and a resistor R104, wherein one end of the resistor R103 is connected to the power supply voltage, and the other end of the resistor R103 is connected to one end of the contact adhesion detection pin of the relay, and the other end of the contact adhesion detection pin is respectively connected to one end of the resistor R108, the diode D102, one end of the capacitor C103, and one end of the resistor R104, wherein the diode D102 is a TVS protection diode.

7. A leakage detection circuit according to claim 6, characterized in that: The relay adhesion detection circuit includes: the other end of the resistor R108 is grounded, the diode D102 and the capacitor C103 are connected in parallel, and the other end of the diode D102 is grounded, and the other end of the resistor R104 is connected to the MCU relay adhesion signal detection interface.

8. A leakage detection circuit according to claim 4, characterized in that: The source of the MOS tube Q100 is connected to the +12V RELAY voltage, and the cathode of the diode D100 is connected to the +12V voltage.

9. A leakage detection circuit according to claim 2, characterized in that: The output voltage of the leakage sensor in the voltage conversion circuit is +5V, and the conversion voltage is 3.3V.

10. A charging pile, characterized in that: The charging pile is equipped with a leakage detection circuit as described in any one of claims 1 to 8.