Combined current transformer

Abstract

The utility model relates to the technical field of charging piles, in particular to a combined current transformer which comprises a current mutual inductance part and an electric leakage mutual inductance part. Each of the current mutual inductance part and the electric leakage mutual inductance part comprises a bus, an inductance coil and a shell, the buses of the current mutual inductance part and the electric leakage mutual inductance part are U-shaped, the inductance coils of the current mutual inductance part and the electric leakage mutual inductance part are respectively arranged in the respective shells, and the wire ends of the respective inductance coils are respectively connected with the pins. And one end of the bus of the electric leakage mutual inductance part passes through the inductance coil. Shells of the current mutual inductance part and the electric leakage mutual inductance part are in butt joint up and down, one end of a bus of the current mutual inductance part penetrates through the center of an inductance coil of the current mutual inductance part and then penetrates through an inductance coil of the electric leakage mutual inductance part, and a pin of the current mutual inductance part downwards extends out of a shell of the electric leakage mutual inductance part. And gaps in the shells of the current mutual inductance part and the electric leakage mutual inductance part are filled with a packaging material. The combined current transformer has the functions of measuring the main loop current and the leakage current at the same time, and is compact in structure and small in size.

Description

Technical Field

[0001] The utility model relates to the technical field of charging piles, and in particular to a combined current transformer. Background Art

[0002] With the continuous development of new energy vehicle technology, especially the rapid development of the charging pile industry.

[0003] Current transformers and leakage current transformers are core components of charging piles, used to measure main circuit current and detect leakage current, respectively. However, traditional current transformers and leakage current transformers are relatively large and have limited functionality. Therefore, those skilled in the art are seeking to combine these two functions while minimizing their size. Utility Model Content

[0004] The purpose of the utility model is to provide a combined current transformer which has the functions of measuring main circuit current and leakage current, and has a compact structure and a small size.

[0005] In order to achieve the above object, the utility model provides a combined current transformer, comprising:

[0006] The current mutual inductance unit includes a first busbar, a first inductor coil, and a first housing. The first busbar is U-shaped. The first housing has a first inner hollow column disposed inside and a first outer hollow column disposed outside. The two ends of the first busbar pass through the first inner hollow column and the first outer hollow column, respectively. The first inductor coil is disposed within the first housing and sleeved on the outside of the first inner hollow column. The end of the first inductor coil is connected to a first pin, which extends downwardly out of the first housing.

[0007] The leakage mutual inductance unit includes a second busbar, a second inductance coil, and a second housing. The second busbar is U-shaped. The second housing has a second inner hollow column and a third inner hollow column inside, and a second outer hollow column and a third outer hollow column outside. The two ends of the second busbar pass through the third inner hollow column and the third outer hollow column respectively. The second inductance coil is arranged in the second housing and is sleeved on the outside of the second inner hollow column and the third inner hollow column. The wire end of the second inductance coil is connected to the second pin, and the second pin extends downward from the second housing.

[0008] The first shell and the second shell are butted up and down, and the two ends of the first busbar pass through the first inner hollow column and the first outer hollow column, and then pass through the second inner hollow column and the second outer hollow column respectively, and the first pin passes through the second shell and extends downward;

[0009] The gap between the first shell and the second shell is filled with packaging material.

[0010] Optionally, the first busbar is embedded in the first shell when the first shell is molded.

[0011] Optionally, the first inductor coil includes a first annular magnetic core and a first winding, the first winding is formed by winding an enameled wire on the first annular magnetic core, and two wire ends of the first winding are respectively connected to a first pin.

[0012] Optionally, the second inductor coil includes a second annular magnetic core, a second winding, a third winding and a fourth winding, the second winding, the third winding and the fourth winding are all wound by enameled wire on the second annular magnetic core, and the second winding, the third winding and the fourth winding are spaced apart in the circumferential direction, the number of turns of the third winding is less than that of the second winding and the fourth winding, and the number of turns of the second winding and the fourth winding is the same, the third winding is located between the second winding and the fourth winding, and the two wire ends of each winding in the second winding, the third winding and the fourth winding are respectively connected to a second pin.

[0013] Optionally, an annular shielding shell made of low remanent magnetism material is further provided on the outer side of the second inductor coil, and openings are formed on the annular shielding shell for the wire ends of the second winding, the third winding and the fourth winding to pass through.

[0014] Optionally, the first pin and the second pin are located in the same area to form a pin header for external connection.

[0015] Optionally, a first shielding baffle is provided between the first busbar and the second busbar;

[0016] A second shielding baffle is provided between the pin row and the adjacent busbar.

[0017] Optionally, the first annular magnetic core and the second annular magnetic core are ultra-microcrystalline rings.

[0018] Optionally, an insert block is provided at the lower end of the first shell, and a groove is provided at the upper end of the second shell. When the first shell and the second shell are docked, the insert block is inserted into the groove.

[0019] Optionally, the encapsulation material is any one of epoxy resin, polyurethane, and silicone rubber.

[0020] The above technical solution of the utility model has the following advantages:

[0021] The utility model provides a combined current transformer, comprising a current mutual inductance unit and a leakage mutual inductance unit. The current mutual inductance unit comprises a first busbar, a first inductance coil, and a first housing. The first busbar is U-shaped, with a first inner hollow column provided inside the first housing and a first outer hollow column provided outside the first housing. The two ends of the first busbar pass through the first inner hollow column and the first outer hollow column respectively. The first inductance coil is arranged in the first housing and sleeved on the outside of the first inner hollow column. The wire end of the first inductance coil is connected to the first pin. The leakage mutual inductance unit comprises a second busbar, a second inductance coil, and a second housing. The second busbar is U-shaped, with a second inner hollow column and a third inner hollow column provided inside the second housing, and a second outer hollow column and a third outer hollow column provided outside the second housing. The two ends of the second busbar pass through the third inner hollow column and the third outer hollow column respectively. The second inductance coil is arranged in the second housing and sleeved on the outside of the second inner hollow column and the third inner hollow column. The wire end of the second inductance coil is connected to the second pin, and the second pin extends downwardly out of the second housing. The first and second housings are butted together vertically. The two ends of the first busbar pass through the first inner and outer hollow columns, then exit through the second inner and outer hollow columns, respectively. The first pin extends downward through the second housing. The gap between the first and second housings is filled with potting compound. This combined current transformer simultaneously measures main circuit current and leakage current, while maintaining a compact design and small size. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings of the present invention are provided for illustrative purposes only, and the proportions and quantities of the components in the drawings may not necessarily be consistent with the actual product.

[0023] Figure 1 This is a side structural diagram of a combined current transformer in an embodiment of the present utility model;

[0024] Figure 2 yes Figure 1 Schematic diagram of the structure of the combined current transformer in the middle;

[0025] Figure 3 yes Figure 1 A structural diagram of the combined current transformer from another angle;

[0026] Figure 4 yes Figure 1 Schematic diagram of the exploded state of the combined current transformer;

[0027] Figure 5 yes Figure 1 Schematic diagram of the exploded state of the combined current transformer from another angle;

[0028] Figure 6 This is a schematic top view of the second housing in an embodiment of the present utility model;

[0029] Figure 7This is a schematic structural diagram of a first inductor coil in an embodiment of the present utility model;

[0030] Figure 8 This is a schematic structural diagram of a second inductor coil in an embodiment of the present utility model;

[0031] Figure 9 This is a schematic structural diagram of an annular shielding shell in an embodiment of the present utility model;

[0032] Figure 10 This is a structural diagram of a first shielding baffle in an embodiment of the present utility model;

[0033] Figure 11 It is a structural schematic diagram of a second shielding baffle in an embodiment of the present utility model.

[0034] In the picture:

[0035] 1: Current mutual inductance part;

[0036] 11: First busbar;

[0037] 12: first inductor coil;

[0038] 121: first annular magnetic core;

[0039] 122: first winding;

[0040] 13: first shell;

[0041] 131: first inner hollow column;

[0042] 132: first outer hollow column;

[0043] 133: plug-in block;

[0044] 14: First pin;

[0045] 2: Leakage mutual inductance;

[0046] 21: Second busbar;

[0047] 22: second inductor coil;

[0048] 221: second annular magnetic core;

[0049] 222: Second winding;

[0050] 223: tertiary winding;

[0051] 224: fourth winding;

[0052] 23: second shell;

[0053] 231: second inner hollow column;

[0054] 232: third inner hollow column;

[0055] 233: second outer hollow column;

[0056] 234: third outer hollow column;

[0057] 235: groove;

[0058] 24: Second pin;

[0059] 25: first shielding baffle;

[0060] 26: second shielding baffle;

[0061] 27: Annular shielding shell. DETAILED DESCRIPTION

[0062] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0063] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0064] Furthermore, the terms “first,” “second,” “third,” and “fourth” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0065] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0066] like Figures 1 to 5 As shown, the combined current transformer provided by the embodiment of the present utility model includes a current mutual inductance part 1 and a leakage mutual inductance part 2.

[0067] Among them, the current mutual inductance part 1 includes a first busbar 11, a first inductor coil 12 and a first shell 13. The first busbar 11 is U-shaped. A first inner hollow column 131 is provided inside the first shell 13, and a first outer hollow column 132 is provided outside the first shell. The two ends of the first busbar 11 pass through the first inner hollow column 131 and the first outer hollow column 132 respectively. The first inductor coil 12 is arranged in the first shell 13 and is sleeved on the outside of the first inner hollow column 131. The wire end of the first inductor coil 12 is connected to the first pin 14, and the first pin 14 extends downward from the first shell 13.

[0068] The leakage mutual inductance part 2 includes a second busbar 21, a second inductance coil 22 and a second shell 23. The second busbar 21 is U-shaped. The interior of the second shell 23 is provided with a second inner hollow column 231 and a third inner hollow column 232, and the outside is provided with a second outer hollow column 233 and a third outer hollow column 234. The two ends of the second busbar 21 pass through the third inner hollow column 232 and the third outer hollow column 234 respectively. The second inductance coil 22 is arranged in the second shell 23 and is sleeved on the outside of the second inner hollow column 231 and the third inner hollow column 232. The wire end of the second inductance coil 22 is connected to the second pin 24, and the second pin 24 extends downward from the second shell 23.

[0069] The assembled current transformer 1 and leakage transformer 2 are potted separately. In this embodiment, the potting material (not shown) is made using existing technology and solidifies from a liquid state during potting to achieve encapsulation. The potting material flows into the semi-finished product and can penetrate all gaps, achieving dustproofing, waterproofing, corrosion resistance, aging resistance, and improved electrical strength. In some examples, the potting material can be made of materials such as epoxy resin, polyurethane, and silicone rubber.

[0070] After the encapsulating material solidifies, the encapsulated current transformer 1 and leakage transformer 2 are assembled, with the first housing 13 and second housing 23 butted against each other. The two ends of the first busbar 11 pass through the first inner hollow column 131 and the first outer hollow column 132, then exit through the second inner hollow column 231 and the second outer hollow column 233, respectively. The first pin 14 extends downward through the second housing 23, completing the assembly of the current transformer 1 and leakage transformer 2. This combined current transformer simultaneously measures both main circuit current and leakage current, while maintaining a compact structure and small size.

[0071] In one example, the first busbar 11 is embedded in the first shell 13 when the first shell 13 is formed, thereby achieving an integral connection between the two, avoiding gaps between the first busbar 11 and the first shell 13, achieving a more stable connection, and reducing assembly workload.

[0072] The first inductor 12 can be selected from the corresponding structures in the prior art according to the measurement requirements. Figure 6As shown, in this embodiment, the first inductor 12 includes a first annular core 121 and a first winding 122 . The first winding 122 is formed by winding enameled wire on the first annular core 121 . Two wire ends of the first winding 122 are respectively connected to a first pin 14 .

[0073] See also Figure 7 As shown, the second inductor 22 includes a second annular magnetic core 221, a second winding 222, a third winding 223 and a fourth winding 224, wherein the second winding 222, the third winding 223 and the fourth winding 224 are all formed by winding enameled wire on the second annular magnetic core 221, and the second winding 222, the third winding 223 and the fourth winding 224 are arranged at intervals in the circumferential direction, the number of turns of the third winding 223 is less than that of the second winding 222 and the fourth winding 224, and the number of turns of the second winding 222 and the fourth winding 224 are the same, the third winding 223 is located between the second winding 222 and the fourth winding 224, and the two wire ends of each winding in the second winding 222, the third winding 223 and the fourth winding 224 are respectively connected to a second pin 24.

[0074] To shield against magnetic field influences, see Figure 8 As shown, in this embodiment, an annular shielding shell 27 made of a low remanent magnetism material is further provided on the outer side of the second inductor 22. The annular shielding shell 27 has openings for the wire ends of the second winding 222, the third winding 223, and the fourth winding 224 to pass through. The annular shielding shell includes an annular shell and a detachable annular cover.

[0075] To facilitate connection, in this embodiment, the first pin 14 and the second pin 24 are located in the same area to form a pin header for external connection.

[0076] In order to improve the electrical strength between the busbar and the pin and reduce the impact between the busbars, a first shielding baffle 25 is provided between the first busbar 11 and the second busbar 21. A second shielding baffle 26 is provided between the pin and the adjacent busbar. Figures 1 to 5 As shown, in the solution where the first pin 14 and the second pin 24 form a pin header, a second shielding baffle 26 is provided between the pin header and the second busbar 21 .

[0077] In order to further improve the measurement accuracy, in this embodiment, the first annular magnetic core 121 and the second annular magnetic core 221 use ultra-microcrystalline rings with relatively high initial magnetic permeability as the magnetic cores, which not only have high accuracy but also small size.

[0078] In order to achieve accurate positioning and docking of the current mutual inductance part 1 and the leakage mutual inductance part 2 and prevent circumferential rotation, see Figure 4 and Figure 5As shown, in this embodiment, an insert block 133 is provided at the lower end of the first shell 13 , and a groove 235 is provided at the upper end of the second shell 23 . When the first shell 13 and the second shell 23 are docked, the insert block 133 is inserted into the groove 235 .

[0079] The combined current transformer in this embodiment is fully enclosed, offering excellent environmental resistance, high insulation strength, and resistance to shock and moisture. Combining two different functional transformers into one unit creates a compact structure and small size, effectively saving space. Of course, the current transformer and leakage transformer can be separated and used independently if needed.

[0080] In a specific example of the solution of the present invention, the first annular magnetic core is an ultra-fine crystal ring with an outer diameter of 20 mm, an inner diameter of 16 mm, and a height (axial dimension) of 8 mm, and is wound with 2000 turns of 2UEWΦ0.10 mm enameled wire. The second annular magnetic core is an ultra-fine crystal ring with an outer diameter of 20 mm, an inner diameter of 18 mm, and a height (axial dimension) of 3.2 mm, and is wound with two groups of 75 turns and one group of 5 turns respectively of 2UEWΦ0.20 mm enameled wire. It is potted with epoxy resin and assembled together after potting. An annular shielding shell is provided around the outside of the second inductor coil. A first shielding baffle is provided between the first busbar and the second busbar. A second shielding baffle is provided between the pin header and the adjacent busbar.

[0081] The technical parameters of the combined current transformer are detailed in Table 1.

[0082] Table 1:

[0083]

[0084]

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that not every embodiment contains only one independent technical solution. In the absence of a conflict of solutions, the various technical features mentioned in each embodiment can be combined in any manner to form other implementation methods that can be understood by those skilled in the art.

[0086] In addition, without departing from the scope of the present invention, the technical solutions described in the aforementioned embodiments may be modified, or some of the technical features thereof may be replaced by equivalents, without causing the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combined current transformer, characterized in that: include: The current mutual inductance unit includes a first busbar, a first inductor coil, and a first housing. The first busbar is U-shaped. The first housing has a first inner hollow column disposed therein and a first outer hollow column disposed thereout. The first busbar passes through the first inner hollow column and the first outer hollow column at both ends. The first inductor coil is disposed within the first housing and sleeved around the outer side of the first inner hollow column. The first inductor coil has a wire end connected to a first pin, which extends downwardly out of the first housing. The leakage mutual inductance unit includes a second busbar, a second inductance coil, and a second shell. The second busbar is U-shaped. The second shell has a second inner hollow column and a third inner hollow column inside, and a second outer hollow column and a third outer hollow column outside. The two ends of the second busbar pass through the third inner hollow column and the third outer hollow column respectively. The second inductance coil is arranged in the second shell and is sleeved on the outside of the second inner hollow column and the third inner hollow column. The wire end of the second inductance coil is connected to the second pin, and the second pin extends downward from the second shell. The first shell and the second shell are butted against each other in an upper and lower manner. The two ends of the first busbar pass through the first inner hollow column and the first outer hollow column and then pass through the second inner hollow column and the second outer hollow column respectively. The first pin passes through the second shell and extends downward. The gaps between the first shell and the second shell are filled with packaging material.

2. The combined current transformer according to claim 1, characterized in that: The first busbar is embedded in the first shell when the first shell is formed.

3. The combined current transformer according to claim 1, characterized in that: The first inductor coil includes a first annular magnetic core and a first winding. The first winding is formed by winding an enameled wire on the first annular magnetic core. Two wire ends of the first winding are respectively connected to a first pin.

4. The combined current transformer according to claim 3, characterized in that: The second inductor coil includes a second annular magnetic core, a second winding, a third winding and a fourth winding. The second winding, the third winding and the fourth winding are all made of enameled wire wound on the second annular magnetic core, and the second winding, the third winding and the fourth winding are arranged at intervals in the circumferential direction. The number of turns of the third winding is less than that of the second winding and the fourth winding, and the number of turns of the second winding and the fourth winding is the same. The third winding is located between the second winding and the fourth winding. The two wire ends of each winding in the second winding, the third winding and the fourth winding are respectively connected to a second pin.

5. The combined current transformer according to claim 4, characterized in that: An annular shielding shell made of a low remanent magnetism material is further provided on the outer side of the second inductor coil. The annular shielding shell is provided with openings for the wire ends of the second winding, the third winding and the fourth winding to pass through.

6. The combined current transformer according to claim 4, characterized in that: The first pin and the second pin are located in the same area to form a pin header for external connection.

7. The combined current transformer according to claim 6, characterized in that: A first shielding baffle is provided between the first busbar and the second busbar; A second shielding baffle is provided between the pin row and the adjacent busbar.

8. The combined current transformer according to claim 4, characterized in that: The first annular magnetic core and the second annular magnetic core are ultra-microcrystalline rings.

9. The combined current transformer according to claim 1, characterized in that: An insert block is provided at the lower end of the first shell, and a groove is provided at the upper end of the second shell. When the first shell and the second shell are docked, the insert block is inserted into the groove.

10. The combined current transformer according to claim 1, characterized in that: The packaging material is any one of epoxy resin, polyurethane and silicone rubber.

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