Leakage current transformer and charging device comprising same
By employing a design that stacks cylindrical mounting cavities axially in the leakage current transformer, a compact structure for the leakage current transformer is achieved, solving the problem of large size in existing technologies and optimizing the space utilization of charging piles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANJING SHENQI ELECTRONICS TECH CO LTD
- Filing Date
- 2025-09-02
- Publication Date
- 2026-08-04
AI Technical Summary
Existing current transformers are large in size and occupy a lot of space in electric vehicle charging stations, making it difficult to effectively reduce their size.
A leakage current transformer is designed, which adopts an axial stacking structure of cylindrical mounting cavities inside the housing. The transformer windings, magnetic rings and PCB control boards are tightly stacked, and the wiring is routed through the wire guide posts to reduce the space occupied.
A compact design for the leakage current transformer has been achieved, reducing the space occupied by the charging device while ensuring the effectiveness of leakage current detection and a neat wiring structure.
Smart Images
Figure CN224595361U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of electric vehicle charging devices, specifically to a leakage current transformer and a charging device containing the same. Background Technology
[0002] The electric vehicle industry is a complex undertaking, and electric vehicle charging is one of its key components. To prevent leakage, charging stations require electronic components specifically designed to detect electrical leaks.
[0003] Various types of current transformers for detecting leakage current have been disclosed in known technologies. However, current transformers currently on the market still have the problem of being large in size and taking up a lot of space when applied to charging piles. Utility Model Content
[0004] The purpose of this utility model is to provide a leakage current transformer and a charging device containing the same. By tightly stacking and storing the sensing components of the leakage current transformer in the housing, and making it easy to define boundaries, the volume of the leakage current transformer can be effectively reduced, and the space occupied by the charging pile control module can be optimized.
[0005] To achieve the above objectives, the first aspect of this utility model provides a leakage current transformer for leakage current detection in a new energy vehicle charging device. The leakage current transformer includes: a housing, a cover, a transformer winding, a magnetic ring, and a PCB control board.
[0006] The housing has a first mounting cavity and a second mounting cavity, both of which are cylindrical and stacked along the axial direction; the diameter of the first mounting cavity is smaller than the diameter of the second mounting cavity.
[0007] The current transformer winding is disposed in the first mounting cavity, and the magnetic ring and the PCB control board are stacked sequentially in the second mounting cavity, with the magnetic ring sandwiched between the current transformer winding and the PCB control board.
[0008] The current transformer winding, magnetic ring, and PCB control board are coupled together and used for leakage detection of the charging device.
[0009] The cover is provided over the opening of the housing and is detachably connected to the housing;
[0010] The housing is also provided with a first wire guide post extending axially along the first mounting cavity and the second mounting cavity, and the current transformer winding, magnetic ring and PCB control board are all sleeved on the first wire guide post.
[0011] The housing is further provided with a second wire guide post extending axially along the second mounting cavity; the second wire guide post passes through the magnetic ring and the PCB control board.
[0012] As one embodiment, the housing and the cover are connected by a snap-fit connection.
[0013] As one embodiment, the cover is provided with a plurality of male buckles arranged at intervals along the circumference, and the inner wall of the opening of the second mounting cavity of the housing is provided with a plurality of female buckles. The housing and the cover are connected by the plurality of male buckles and the plurality of female buckles.
[0014] As one embodiment, there are four male and four female buckles, which are evenly distributed circumferentially.
[0015] As one embodiment, the first wire guide post is coaxially arranged with the first mounting cavity.
[0016] As one embodiment, the second wire guide post is eccentrically positioned relative to the second mounting cavity.
[0017] As an example, the leakage current transformer is a type B transformer.
[0018] As one embodiment, the inner side of the cover is provided with reinforcing ribs.
[0019] As one embodiment, the cover has wire holes adapted to the PCB control board.
[0020] A second aspect of this invention provides a charging device comprising the leakage current transformer as described above.
[0021] Compared with the prior art, the beneficial effects of this utility model are:
[0022] The housing of the leakage current transformer in this embodiment has a first mounting cavity and a second mounting cavity. Both the first and second mounting cavities are cylindrical and stacked axially. The diameter of the first mounting cavity is smaller than that of the second mounting cavity. The transformer winding is disposed in the first mounting cavity, and the magnetic ring and PCB control board are stacked sequentially in the second mounting cavity, with the magnetic ring sandwiched between the transformer winding and the PCB control board. The transformer winding, magnetic ring, and PCB control board are coupled and used for leakage detection of the charging device. A cover is disposed on the opening of the housing and is detachably connected to the housing. The housing also has a first wire guide post extending axially along the first and second mounting cavities, and the transformer winding, magnetic ring, and PCB control board are all sleeved on the first wire guide post. The housing also has a second wire guide post extending axially along the second mounting cavity. The second wire guide post passes through the magnetic ring and the PCB control board. Therefore, the transformer winding, magnetic ring, and PCB control board are compactly stacked in the space inside the housing, and the wiring is routed through the second wire guide post, which not only makes the wiring neat but also does not occupy additional space. Attached Figure Description
[0023] Figure 1This is a schematic diagram of the overall structure of the leakage current transformer according to an embodiment of the present utility model;
[0024] Figure 2 for Figure 1 The diagram shown is an exploded view of the leakage current transformer.
[0025] Figure 3 for Figure 1 The diagram shows a cross-sectional structure of a leakage current transformer.
[0026] Figure 4 for Figure 1 The diagram shows the structural structure of the cover of the leakage current transformer;
[0027] Figure 5 for Figure 1 The diagram shows the structural structure of the housing of the leakage current transformer.
[0028] In the diagram: 1. Housing; 2. Current transformer winding; 3. Magnetic ring; 4. PCB control board; 5. Cover; 6. First wire guide post; 7. Second wire guide post; 51. Male buckle; 52. Wire guide hole; 11. Female buckle; 100. Residual current transformer. Detailed Implementation
[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0030] Please see Figures 1-5 This utility model provides a leakage current transformer 100 for leakage current detection in a new energy vehicle charging device. The leakage current transformer includes: a housing 1, a cover 5, a transformer winding 2, a magnetic ring 3, and a PCB control board 4.
[0031] The housing 1 has a first mounting cavity and a second mounting cavity. Both the first mounting cavity and the second mounting cavity are cylindrical and stacked along the axial direction. The diameter of the first mounting cavity is smaller than the diameter of the second mounting cavity.
[0032] The current transformer winding 2 is disposed in the first mounting cavity, and the magnetic ring 3 and the PCB control board 4 are stacked sequentially in the second mounting cavity, with the magnetic ring 3 sandwiched between the current transformer winding 2 and the PCB control board 4. The current transformer winding 2, the magnetic ring 3, and the PCB control board 4 are coupled together and used for leakage current detection of the charging device.
[0033] The cover 5 is placed over the opening of the housing 1 and is detachably connected to the housing 1. The housing 1 is also provided with a first wire guide post 6 extending axially along the first mounting cavity and the second mounting cavity. The current transformer winding 2, the magnetic ring 3 and the PCB control board 4 are all sleeved on the first wire guide post 6.
[0034] The housing 1 is also provided with a second wire guide post 7 extending axially along the second mounting cavity, and the second wire guide post 7 passes through the magnetic ring 3 and the PCB control board 4.
[0035] In this embodiment of the utility model, the shell 1 and the cover 5 are connected by a snap-fit connection. Specifically,
[0036] The cover 5 is provided with a plurality of male buckles 51 arranged at intervals along the circumference, and the inner wall of the opening of the second mounting cavity of the housing 1 is provided with a plurality of female buckles 11. The housing 1 and the cover 5 are connected by the plurality of male buckles 51 and the plurality of female buckles 11. Preferably, there are four male buckles 51 and four female buckles 11, which are evenly arranged along the circumference.
[0037] The first wire guide post 6 is made of insulating material and is coaxially arranged with the first mounting cavity, facilitating the connection of the current transformer winding with the live and neutral wires of the charging device, maintaining neat wiring while saving space. The second wire guide post 7 is eccentrically arranged with the second mounting cavity. The second wire guide post 7 is also made of insulating material. The first wire guide post 6 and the second wire guide post 7 can also be used to position the PCB control board 4.
[0038] In this embodiment of the utility model, the leakage current transformer can be a type B transformer, specifically a type B (A+6) leakage current transformer. The type B transformer uses precious metal alloy materials (such as platinum-rhodium alloy), which have excellent thermal stability and measurement accuracy, and are suitable for complex working conditions.
[0039] As an example, the inner side of the cover 5 is provided with reinforcing ribs, which can improve the strength of the cover 5 and ensure the service life of the leakage current transformer.
[0040] As an example, the cover 5 is provided with a wire hole 52 that is adapted to the PCB control board 4, so as to facilitate the electrical connection of the PCB control board.
[0041] The working principle of this leakage current transformer is as follows: During use, the primary winding of the transformer is connected in series in the main circuit of the charging pile, while the secondary winding is connected to the signal input terminal of the PCB control board. When current flows through the primary winding, the secondary winding induces a voltage signal proportional to the current change. A magnetic ring forms a tight magnetic coupling with the winding. The high magnetic permeability of the magnetic ring enhances the electromagnetic induction efficiency between the primary and secondary windings, while suppressing external electromagnetic interference. The PCB control board is connected to the secondary winding of the transformer via wires to receive its output induced signal. The PCB control board integrates signal amplification circuits, filtering circuits, comparators, and microcontrollers to process and analyze the leakage current signal. When the charging pile is working normally, the currents in the live wire and neutral wire are equal in magnitude and opposite in direction, and the magnetic fields they generate cancel each other out. At this time, the net magnetic field induced by the secondary winding of the transformer is zero, and there is no induced signal output; the PCB control board determines this to be a normal state. When a charging station experiences a leakage current (such as insulation damage or electric shock), some current leaks through the grounding path, causing an imbalance between the live and neutral wire currents. At this time, a net magnetic field is generated in the primary winding of the current transformer. The secondary winding senses this change in magnetic field and outputs a corresponding voltage signal. The secondary winding of the current transformer transmits the induced signal to the PCB control board. The PCB control board amplifies and filters the signal to remove noise interference. The microcontroller or comparator analyzes the signal amplitude; if it exceeds a preset threshold (such as 15mA or 30mA), it is determined to be a leakage fault. The PCB control board immediately triggers a protection mechanism (such as driving a relay to disconnect the main circuit), cutting off the power supply and preventing electric shock accidents.
[0042] Compared with the prior art, the leakage current transformer of this utility model has a housing with a first mounting cavity and a second mounting cavity. Both the first and second mounting cavities are cylindrical and stacked along the axial direction. The diameter of the first mounting cavity is smaller than the diameter of the second mounting cavity. The transformer winding is disposed in the first mounting cavity, and the magnetic ring and PCB control board are stacked sequentially in the second mounting cavity, with the magnetic ring sandwiched between the transformer winding and the PCB control board. The transformer winding, magnetic ring, and PCB control board are coupled and used for leakage current detection of the charging device. The cover is placed over the opening of the housing and is detachably connected to the housing; the housing also has a first wire guide post extending axially along the first mounting cavity and the second mounting cavity, and the current transformer winding, magnetic ring and PCB control board are all sleeved on the first wire guide post; the housing also has a second wire guide post extending axially along the second mounting cavity; the second wire guide post passes through the magnetic ring and the PCB control board, so the current transformer winding, magnetic ring and PCB control board are compactly stacked in the space inside the housing, and the wiring is routed through the second wire guide post, which not only makes the wiring neat but also does not take up extra space.
[0043] This utility model provides a charging device in embodiment two, including a leakage current transformer as described in the first embodiment.
[0044] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
Claims
1. A current transformer, characterized by For leakage current detection in new energy vehicle charging devices, the leakage current transformer includes: a housing, a cover, a transformer winding, a magnetic ring, and a PCB control board; The housing has a first mounting cavity and a second mounting cavity, both of which are cylindrical and stacked along the axial direction; the diameter of the first mounting cavity is smaller than the diameter of the second mounting cavity. The current transformer winding is disposed in the first mounting cavity, and the magnetic ring and the PCB control board are stacked sequentially in the second mounting cavity, with the magnetic ring sandwiched between the current transformer winding and the PCB control board. The current transformer winding, magnetic ring, and PCB control board are coupled together and used for leakage detection of the charging device. The cover is provided over the opening of the housing and is detachably connected to the housing; The housing is also provided with a first wire guide post extending axially along the first mounting cavity and the second mounting cavity, and the current transformer winding, magnetic ring and PCB control board are all sleeved on the first wire guide post. The housing is further provided with a second wire guide post extending axially along the second mounting cavity; the second wire guide post passes through the magnetic ring and the PCB control board.
2. The current transformer of claim 1, wherein, The shell and the cover are connected by snap-fit.
3. The current transformer of claim 2, wherein, The cover is provided with a plurality of male buckles arranged at intervals along the circumference, and the inner wall of the opening of the second mounting cavity of the housing is provided with a plurality of female buckles. The housing and the cover are connected by the plurality of male buckles and the plurality of female buckles.
4. The instrument transformer of claim 3, wherein, There are four male and four female buckles, which are evenly distributed circumferentially.
5. The current transformer of claim 1, wherein, The first wire guide post is coaxially arranged with the first mounting cavity.
6. The current transformer of claim 1, wherein, The second wire guide post is eccentrically positioned relative to the second mounting cavity.
7. The instrument transformer of claim 1, wherein, The leakage current transformer is a type B transformer.
8. The current transformer of claim 1, wherein, The inner side of the cover is provided with reinforcing ribs.
9. The instrument transformer of claim 1, wherein, The cover has wire holes adapted to the PCB control board.
10. A charging device, characterized by It includes a leakage current transformer as described in any one of claims 1 to 9.