A charging pile ground fault detection and protection device
Patent Information
- Application Number
- CN202522157350.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-13
- Publication Date
- 2026-10-09
- Estimated Expiration
- 2035-10-13
AI Technical Summary
[0005]本实用新型提供了一种充电桩接地故障检测与保护装置，解决了现有技术中存在霍尔电流传感器的接线座存在松动风险，在设备运行振动时，接线可能不稳，影响信号传输；且防水效果不理想，在户外潮湿、雨水环境下，水汽易进入接线处，导致短路风险增加，影响设备的正常运行和安全性的缺点
本实用新型中接线插头通过定位片与定位插槽精准定位，配合两个十字螺栓的机械收紧，避免插拔式接线因振动导致的松动，有利于提高接线处连接可靠性；接线插头端部的可压缩密封垫片在螺栓收紧后形成双重密封，接线插头内部无进水，提升了防水效果，有利于解决在户外潮湿、雨水环境下的短路风险。
Smart Images
Figure CN224840469U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of charging pile safety protection technology, and in particular to a charging pile grounding fault detection and protection device. Background Technology
[0002] The charging pile grounding fault detection and protection device is used to monitor the charging pile grounding system. When abnormalities such as poor grounding, excessive grounding resistance, or excessive leakage current occur, it automatically triggers protective actions such as power cut-off and alarm prompts. Among them, the Hall sensor is a key component. It is fitted on the charging pile's power input or output cable to collect the leakage current of "phase line-to-ground" and "positive line-to-ground" in real time. The amplification unit amplifies the weak current signal and transmits it to the control unit. When the leakage current exceeds the preset threshold, the control unit cuts off the main power supply and sounds an alarm.
[0003] Currently, the terminal block of the Hall current sensor is at risk of loosening. When the equipment vibrates during operation, the wiring may become unstable, affecting signal transmission. Furthermore, the waterproofing effect is not ideal. In humid or rainy outdoor environments, moisture can easily enter the wiring, increasing the risk of short circuits and affecting the normal operation and safety of the equipment.
[0004] To address the aforementioned issues, this utility model document proposes a grounding fault detection and protection device for charging piles. Utility Model Content
[0005] This utility model provides a charging pile grounding fault detection and protection device, which solves the shortcomings of the prior art, such as the risk of loosening of the terminal block of the Hall current sensor, which may cause unstable wiring when the equipment is vibrating during operation, affecting signal transmission; and the unsatisfactory waterproof effect, which makes it easy for moisture to enter the wiring in humid and rainy outdoor environments, leading to an increased risk of short circuit and affecting the normal operation and safety of the equipment.
[0006] This utility model provides the following technical solution: A grounding fault detection and protection device for charging piles includes: The open-type Hall current sensor body has a four-pin terminal block on one side. The terminal block has four corresponding connectors inserted into it. A compressible sealing gasket is glued to the end of each connector. The other side of the sealing gasket is in close contact with the inner wall of the terminal block. The connectors and the terminal block are tightened by two cross bolts.
[0007] In one possible design, the opening of the open-type Hall current sensor body is connected by a matching hexagon socket bolt and nut, the end of which passes through two through holes in the opening of the open-type Hall current sensor body and is threadedly connected to the nut.
[0008] In one possible design, both ends of the open-type Hall current sensor body base are provided with U-shaped notches for fixing by bolts.
[0009] In one possible design, the top of the connector is integrally formed with a positioning piece, and the top of the inner wall of the connector is provided with a positioning slot for inserting the corresponding positioning piece.
[0010] In one possible design, the connector has two symmetrical through holes I, and a corresponding cross bolt is inserted through the through hole I. The sealing gasket has a through hole II for the threaded end of the corresponding cross bolt to pass through. One side of the inner wall of the connector has a threaded groove for threaded connection of the end of the corresponding cross bolt.
[0011] In one possible design, multiple heat dissipation fins are fixedly disposed on the outer wall of the housing of the open-type Hall current sensor body.
[0012] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit the present invention.
[0013] The working principle and usage process of this technical solution are as follows: During installation, the operator, based on the charging pile cable diameter, loosens the hex bolts and nuts at the opening of the open-type Hall current sensor body, opens the sensor's annular opening, inserts the cable into the center of the sensor core through the opening, closes the opening, and then retightens the hex bolts and nuts. The sensor is then secured to the mounting bracket inside the charging pile's distribution box using bolts through the U-shaped notches at both ends of the sensor base. Afterwards, the four connectors are removed and connected to the signal input terminal of the low-noise operational amplifier and the sensor's power supply terminal, respectively, ensuring correct wiring polarity (e.g., "V+", "V-", "signal"). "+" "signal-"), then align the positioning piece on the top of the connector with the positioning slot on the inner wall of the connector, and insert the connector along the slot direction. The cooperation between the positioning piece and the slot can prevent the connector from being inserted backwards or offset, ensuring the accuracy of the wiring. During the insertion process, the compressible sealing gasket at the end of the connector fits tightly against the inner wall of the connector and is gradually compressed as the connector is inserted to form an initial seal. Take two cross bolts and pass them through the through hole I of the connector and the through hole II of the sealing gasket, respectively, and finally screw them into the threaded groove on the inner wall of the connector. At this time, the sealing gasket is further compressed to achieve waterproof sealing and mechanical anti-loosening at the connection point. After the charging pile is powered on, the isolated power module supplies power to the open-type Hall current sensor, low-noise operational amplifier, and control unit. When the charging pile starts charging (e.g., when the vehicle is connected to the charging gun), the leakage current in the phase-to-ground (AC pile) or positive-to-ground (DC pile) wire of the magnetic core induction cable of the open-type Hall current sensor generates a weak voltage signal proportional to the leakage current based on the Hall effect. This signal is transmitted to the low-noise operational amplifier through a stable connection between the terminal block and the connector. The low-noise operational amplifier (e.g., AD8628) receives the sensor signal and linearly amplifies it according to a preset amplification factor. The integrated RC low-pass filter circuit filters out high-frequency noise in the signal, resulting in a flat output. The DC voltage signal is transmitted to the control unit via the CAN bus. The control unit collects the amplified signal at a sampling rate of 1kHz, converts the voltage value into the actual leakage current value, and compares it with the preset safety threshold. If the leakage current is less than or equal to the safety threshold (30mA for AC charging piles and 100mA for DC charging piles), it is considered normal and continuous monitoring continues. If the leakage current is greater than the safety threshold and the duration is greater than or equal to 50μs (to avoid false triggering due to momentary interference), the control unit sends a power-off command to the protection module, driving the AC circuit breaker (such as DZ47-63C16) or DC contactor (such as CJX2-1210Z) to cut off the main power supply of the charging pile (cutting off the L / N line for AC charging piles and the positive / negative line for DC charging piles).
[0014] This utility model has the following beneficial effects: In this invention, the connector is precisely positioned by a positioning plate and a positioning slot, and mechanically tightened by two cross bolts to prevent loosening of the plug-in connector due to vibration, thus improving the reliability of the connection. The compressible sealing gasket at the end of the connector forms a double seal after the bolts are tightened, preventing water from entering the connector and improving the waterproof effect. This helps to solve the risk of short circuits in humid and rainy outdoor environments. In this invention, the multiple heat dissipation fins on the outer wall of the open-type Hall current sensor housing increase the heat dissipation area. Combined with the air convection in the distribution box, the heat generated by the sensor during operation can be dissipated more quickly, which helps to reduce the operating temperature of the sensor. Attached Figure Description
[0015] Figure 1 A three-dimensional structural diagram of a charging pile grounding fault detection and protection device provided in an embodiment of this utility model; Figure 2 This is a schematic diagram of the structure of a charging pile grounding fault detection and protection device in an open state, provided by an embodiment of the present utility model. Figure 3 A schematic diagram of the terminal block structure of a charging pile grounding fault detection and protection device provided in an embodiment of this utility model; Figure 4This is a schematic diagram of the wiring plug structure of a charging pile grounding fault detection and protection device provided in an embodiment of the present utility model.
[0016] Reference numerals in the attached drawings: 1. Open-type Hall current sensor body; 2. Hex socket bolt; 3. Nut; 4. U-shaped notch; 5. Terminal block; 6. Wiring plug; 7. Positioning plate; 8. Positioning slot; 9. Phillips head bolt; 10. Through hole I; 11. Sealing gasket; 12. Through hole II; 13. Threaded groove; 14. Heat sink fins. Detailed Implementation
[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0018] In the description of this utility model, it should be understood that the terms "opening", "upper", "middle", "length", "inner", etc., which indicate orientation or positional relationship, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0019] To keep the following description of the embodiments of this utility model clear and concise, detailed descriptions of known functions and known components are omitted.
[0020] In one embodiment:
[0021] Please refer to Figure 1-4 A ground fault detection and protection device, comprising: The open-type Hall current sensor body 1 has an aluminum alloy housing. A through hole is machined on each side of the opening. The hexagonal socket bolts 2 and nuts 3 are made of 304 stainless steel with a galvanized finish to prevent corrosion during long-term use. A U-shaped notch 4 is machined at each end of the base of the open-type Hall current sensor body 1 to accommodate M6 mounting bolts, allowing compatibility with mounting holes within a certain spacing range. One side of the open-type Hall current sensor body 1 is fixed with a four-pin connector 5 by screws. The connector 5 is made of nylon 66 and has a temperature resistance of -40℃ to 120℃. The connector 5 has four pins machined inside, each pin corresponding to a connector 6. The connector 6 is made of brass with a tin-plated surface, and there are four connectors. The top of each connector 6 has a positioning piece 7 integrally formed by stamping. The top of the inner wall of the connector 5 has a positioning slot 8 corresponding to the position of each connector 6. The size of the positioning slot 8 matches the positioning piece 7 to ensure that the positioning piece 7 can be fully inserted into the positioning slot 8. Each connector 6 has a compressible sealing gasket 11 glued to its end with epoxy resin. The sealing gasket 11 is made of silicone rubber and has an IP67 waterproof rating. Two through holes I 10 are symmetrically machined on the connector 6, and through holes II 12 are machined on the sealing gasket 11 corresponding to the positions of the through holes I 10. A threaded groove 13 is machined on one side of the inner wall of the connector 5 corresponding to the position of each through hole II 12. The head of the cross bolt 9 is a countersunk cross-head bolt made of 304 stainless steel. Tightening the cross bolt 9 keeps the sealing gasket 11 at the connection between the connector 5 and the connector 6 compressed, effectively preventing rainwater and dust from entering the wiring, preventing short circuits or oxidation at the connection point, and ensuring the stability of signal transmission.
[0022] During assembly, the first step is to secure the open-type Hall current sensor body 1. The operator, based on the actual diameter of the charging pile cable, uses an Allen wrench to loosen the Allen bolt 2 and nut 3 at the opening of the open-type Hall current sensor body 1, opening the annular opening. The power input or output cable of the charging pile is then inserted into the center of the sensor core through the opening. The opening is then closed, and the Allen wrench is used to retighten the Allen bolt 2 and nut 3. Next, M6 mounting bolts are passed through the U-shaped notches 4 at both ends of the base of the open-type Hall current sensor body 1, aligned with the mounting holes on the mounting bracket inside the charging pile distribution box, and the nuts are tightened to secure the sensor to the mounting bracket. After securing, the sensor housing should remain horizontal, without tilting or shaking. The next step is to connect the terminal block 5 and the connector 6. Take out the four connectors 6 and connect them to the signal input terminals of the low-noise operational amplifier and the power supply terminals of the open-type Hall current sensor body 1, respectively. Two connectors 6 are connected to the "V+" and "V-" terminals of the sensor power supply, and the other two are connected to the "signal+" and "signal-" terminals of the signal. When connecting, ensure that the wiring polarity is correct and avoid reverse connection. Then, align the positioning piece 7 on the top of each connector 6 with the corresponding positioning slot 8 on the top of the inner wall of the connector 5, and slowly insert the connector 6 along the direction of the positioning slot 8. During the insertion process, the sealing gasket 11 at the end of the connector 6 will gradually fit against the inner wall of the connector 5. As the insertion depth increases, the sealing gasket 11 begins to compress. When the connector 6 is fully inserted, an initial seal is formed. Next, take two Phillips head bolts 9 and use a Phillips head screwdriver to pass them through the through hole I 10 on the connector 6 and the through hole II 12 on the sealing gasket 11, respectively. Slowly screw them into the threaded groove 13 on the inner wall of the terminal block 5. After tightening, the sealing gasket 11 is further compressed, completely filling the gap between the connector 6 and the terminal block 5, achieving a waterproof seal and mechanical anti-loosening at the connection point. After connecting all four connectors 6 according to the above steps, check whether each connector 6 is secure and without looseness or wobbling. After assembling the sensor and wiring, the low-noise operational amplifier is fixed to the PCB board inside the charging pile's power distribution box with screws. The output of the low-noise operational amplifier is connected to the charging pile's built-in control unit via the CAN bus. The output of the control unit is connected to the protection module. The output of the isolation power supply module is connected to the power supply terminals of the open-type Hall current sensor body 1, the low-noise operational amplifier, and the control unit, respectively, ensuring normal power supply to each component. When the device is put into use, the charging pile power is turned on, and the isolation power supply module starts working, providing a stable voltage to the open-type Hall current sensor body 1, the low-noise operational amplifier, and the control unit. When the charging pile starts charging and the vehicle's charging gun is inserted into the charging interface, the magnetic core of the open-type Hall current sensor body 1 will sense the leakage current in the cable. For AC charging piles, it senses the leakage current between the "phase line and ground line"; for DC charging piles, it senses the leakage current between the "positive terminal and ground line". According to the Hall effect, the open-type Hall current sensor body 1 will generate a weak voltage signal proportional to the leakage current, with a signal range of 0.1-5V. This signal is transmitted to the low-noise operational amplifier through a stable connection between the terminal block 5 and the connector 6. After receiving the signal, the low-noise operational amplifier linearly amplifies it according to the preset amplification factor for the charging pile type. The amplified signal is then processed by an RC low-pass filter circuit integrated around the operational amplifier to filter out high-frequency noise (such as spike signals generated by IGBT power switching), finally outputting a smooth DC voltage signal. This signal is transmitted to the charging pile's built-in control unit via the CAN bus. The control unit acquires the amplified voltage signal at a sampling rate of 1kHz and converts it into an actual leakage current value using a built-in ADC, which is then compared with a preset safety threshold. The safety threshold for AC charging piles is set to 30mA, and for DC charging piles, it is set to 100mA. If the converted leakage current value is less than or equal to the safety threshold, it is considered a normal state, and the control unit continues to monitor the leakage current change. If the leakage current value is greater than the safety threshold, and this state lasts for ≥50μs, the control unit immediately sends a power-off command to the protection module. After receiving the power-off command, the protection module will activate the AC circuit breaker DZ47-63C16 to disconnect the L and N lines of the charging pile if it is an AC charging pile; if it is a DC charging pile, it will activate the DC contactor CJX2-1210Z to disconnect the positive and negative lines of the charging pile, thereby cutting off the main power supply of the charging pile and avoiding safety risks caused by grounding faults.
[0023] This application can be used for grounding fault detection and protection of charging piles, and can also be used in other fields applicable to this application.
[0024] In another embodiment:
[0025] A grounding fault detection and protection device for charging piles, which is used in the field of charging pile safety protection; Please refer to Figure 1 The open-type Hall current sensor body 1 has multiple heat dissipation fins 14 fixed on the outer wall of the housing by die casting process. The heat dissipation fins 14 are distributed along the circumference of the housing and are integrated with the housing. The surface is coated with anti-rust paint, which can adapt to the outdoor humid environment. During the long-term operation of the device, the heat dissipation fins 14 will cooperate with the air convection in the charging pile power distribution box, which is conducive to the dissipation of heat generated by the sensor during operation.
[0026] However, as is well known to those skilled in the art, the working principle and wiring method of the open-type Hall current sensor body 1 are conventional means or common knowledge, and will not be described in detail here. Those skilled in the art can make any selections according to their needs or convenience.
[0027] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.
[0028] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. In the absence of conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A grounding fault detection and protection device for charging piles, characterized in that, include: An open-type Hall current sensor body (1) is provided with a four-pin terminal block (5) on one side. Four corresponding connectors (6) are inserted into the terminal block (5). A compressible sealing gasket (11) is glued to the end of the connector (6). The other side of the sealing gasket (11) is in close contact with the inner wall of the terminal block (5). The connector (6) and the terminal block (5) are tightened by two cross bolts (9).
2. The charging pile grounding fault detection and protection device according to claim 1, characterized in that, The opening of the open-type Hall current sensor body (1) is connected by a matching hexagonal bolt (2) and nut (3). The end of the hexagonal bolt (2) passes through two through holes at the opening of the open-type Hall current sensor body (1) and is threadedly connected to the nut (3).
3. The charging pile grounding fault detection and protection device according to claim 1, characterized in that, Both ends of the base of the open-type Hall current sensor body (1) are provided with U-shaped notches (4) for fixing by bolts.
4. The charging pile grounding fault detection and protection device according to claim 1, characterized in that, The top of the connector (6) is integrally formed with a positioning piece (7), and the top of the inner wall of the connector (5) is provided with a positioning slot (8) for inserting the corresponding positioning piece (7).
5. The charging pile grounding fault detection and protection device according to claim 4, characterized in that, The connector (6) is symmetrically provided with two through holes I (10), and a corresponding cross bolt (9) is provided through the through hole I (10). The sealing gasket (11) is provided with a through hole II (12) for the thread end of the corresponding cross bolt (9) to pass through. The inner wall of the connector (5) is provided with a thread groove (13) for threaded connection of the end of the corresponding cross bolt (9).
6. The charging pile grounding fault detection and protection device according to claim 1, characterized in that, Multiple heat dissipation fins (14) are fixedly installed on the outer wall of the housing of the open-type Hall current sensor body (1).