A zero-sequence current transformer and circuit breaker
By uniformly winding the outer coil and inner coil in the zero-sequence current transformer of the circuit breaker and setting an insulating circle, the problem of poor current measurement accuracy of the existing circuit breaker is solved, and high-precision current detection and anti-interference effect are achieved.
Patent Information
- Application Number
- CN202421456676.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-25
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2034-06-25
AI Technical Summary
The current measurement accuracy of existing circuit breakers is poor in the residual current protection, which is easily disturbed and difficult to meet the requirements of small current measurement accuracy.
A zero-sequence current transformer is designed to achieve accurate detection and signal interference shielding by uniformly winding the outer coil and the inner coil on the outside of the magnetic core ring, and an insulating ring layer is set between the outer coil and the inner coil.
It improves the precise detection capability of the circuit breaker for current, enhances the anti-interference ability, and realizes high-precision leakage protection and residual current monitoring.
Smart Images
Figure CN222749325U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of circuit breakers, and in particular to a zero-sequence current transformer and a circuit breaker. Background Art
[0002] A circuit breaker is an electrical device installed in a distribution board. When the current in the circuit is normal, it protects the circuits and equipment of the electrical system by performing circuit switching operations. When abnormal current occurs, such as overload, short circuit, ground fault or similar conditions, it protects the circuits and equipment of the electrical system by performing circuit breaking operations.
[0003] Existing circuit breakers use current transformers to both draw power and measure current. When residual current protection is required, the existing solution is to install a residual current protection module, the space of which is mainly for the zero-sequence current transformer and the wire passing through the zero-sequence current transformer; however, only one Rogowski coil is used. This method has poor current measurement accuracy and is easily interfered with, making it difficult to meet the requirements for small current measurement accuracy. Utility Model Content
[0004] The present application provides a zero-sequence current transformer and circuit breaker with leakage protection and residual current monitoring functions, which can effectively realize accurate detection, improve the accuracy of sensing, and shield signal interference effects in other directions.
[0005] A zero-sequence current transformer provided in this application adopts the following technical solution:
[0006] A zero-sequence current transformer comprises an outer shell, wherein the outer shell is hollow and formed with a U-shaped ring groove, a magnetic core ring is arranged in the U-shaped ring groove, an inner coil for a leakage protection chip is evenly wound around the circumference of the magnetic core ring, an insulating ring layer is wound around the circumference of the inner coil, an outer coil for a residual current monitoring microcontroller is evenly wound around the circumference of the insulating ring layer, the inner coil is connected to a lead terminal 1, and the outer coil is connected to a lead terminal 2.
[0007] Preferably, the inner coil and the outer coil have the same number of turns.
[0008] Preferably, the gap between the U-shaped ring groove and the outer coil is filled with an epoxy resin glue layer.
[0009] Preferably, the cross section of the shell is circular.
[0010] Preferably, the insulating ring layer is an insulating tape ring layer.
[0011] A circuit breaker comprises a housing, a handle rotatably mounted on the housing, the above-mentioned zero-sequence current transformer, a moving contact operating mechanism mounted in the housing and a current release, wherein the housing is provided with an incoming line terminal and an outgoing line terminal for connecting a wire, the handle is movably connected with a connecting rod, the other end of the connecting rod is connected with the moving contact operating mechanism, the moving contact operating mechanism is connected with a moving contact, the current release is connected with a stationary contact, the zero-sequence current transformer is electrically connected with the current release, the stationary contact is electrically connected with the incoming line terminal, the moving contact is electrically connected with the outgoing line terminal, the handle rotates and drives the moving contact operating mechanism to operate so as to realize the connection or disconnection of the moving contact and the stationary contact.
[0012] In summary, the present application includes at least one of the following beneficial technical effects:
[0013] By evenly winding the outer coil and the inner coil on the outside of the magnetic core, accurate detection can be effectively achieved, leakage protection and residual current monitoring can be performed on the circuit breaker access current, accurate detection can be effectively achieved, and the accuracy of induction can be improved. At the same time, an insulating layer is provided between the outer coil and the inner coil to shield signal interference from other directions, with high precision and strong anti-interference ability.
[0014] By using epoxy resin to encapsulate the gap between the shell and the outer coil as the outer insulation of the product, the anti-interference effect of the zero-sequence current transformer is improved;
[0015] The current state is monitored in real time through the zero-sequence current transformer, and leakage protection and residual current monitoring are performed on the circuit breaker access current, which improves the accuracy of induction, shields signal interference from other directions, and can effectively achieve the effect of accurate detection; when the zero-sequence current transformer detects current abnormality, the monitoring feedback is applied to the current release in the leakage circuit breaker, so that the current release is electrically connected and drives the moving contact operating mechanism to operate to realize the disconnection of the moving contact and the static contact, thereby achieving the leakage protection function of the circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is the front view of the zero-sequence current transformer;
[0017] Figure 2 yes Figure 1 Sectional view at AA in the middle;
[0018] Figure 3 This is a front view of the circuit breaker with one side of the casing removed.
[0019] Explanation of the accompanying reference numerals: 1. outer shell; 2. magnetic core coil; 3. inner coil; 4. insulating layer; 5. outer coil; 6. lead terminal one; 7. lead terminal two; 8. epoxy resin layer; 9. shell; 10. handle; 11. zero-sequence current transformer; 12. moving contact operating mechanism; 13. current release; 14. incoming terminal; 15. outgoing terminal; 16. connecting rod; 17. moving contact; 18. static contact. DETAILED DESCRIPTION
[0020] The present application is further described in detail below in conjunction with the accompanying drawings. Example
[0021] An embodiment of the present application discloses a zero-sequence current transformer.
[0022] Reference Figure 1 , Figure 2 The zero-sequence current transformer comprises a hollow shell 1 formed with a U-shaped ring groove, and the cross-section of the shell 1 is set to be circular; a magnetic core ring 2 is arranged in the U-shaped ring groove, an inner coil 3 for a leakage protection chip is evenly wound around the circumference of the magnetic core ring 2, an insulating ring layer 4 is wound around the circumference of the inner coil 3, and the insulating ring layer 4 is an insulating tape ring layer; an outer coil 5 for a residual current monitoring microcontroller is evenly wound around the circumference of the insulating ring layer 4, the inner coil 3 is connected to a lead terminal 1 6, and the outer coil 5 is connected to a lead terminal 2 7.
[0023] The inner coil 3 and the outer coil 5 have the same number of turns, and the gap between the U-shaped ring groove and the outer coil 5 is filled with an epoxy resin adhesive layer 8 .
[0024] The shell 1 is made of PA6 material, and the insulating tape layer is a horse-drawn tape; the magnetic core 2 is ultra-microcrystalline 1K107, and the saturation magnetic density is 1.25T, and the resistivity is 64 micro-ohms. The inner coil 3 is evenly wound on the entire magnetic core 2, and no leakage is allowed; the outer coil 5 is evenly wound on the insulating layer 4, and no leakage is allowed.
[0025] The implementation principle is: by evenly winding the outer coil 5 and the inner coil 3 on the outside of the magnetic core ring 2, accurate detection can be effectively achieved, leakage protection and residual current monitoring can be performed on the circuit breaker access current, and the accuracy of induction can be improved. At the same time, an insulating layer 4 is provided between the outer coil 5 and the inner coil 3 to shield signal interference in other directions; the gap between the outer shell 1 and the outer coil 5 is encapsulated with epoxy resin as the external insulation of the product, thereby improving the anti-interference effect of the zero-sequence current transformer. Example
[0026] An embodiment of the present application discloses a circuit breaker with a zero-sequence current transformer.
[0027] Reference Figure 3The circuit breaker includes a housing 9, a handle 10 rotatably mounted on the housing 9, a zero-sequence current transformer 11 in Example 1, a moving contact 17 operating mechanism 12 installed in the housing 9, and a current release 13; the housing 9 is provided with an inlet terminal 14 and an outlet terminal 15 for connecting a wire, the handle 10 is movably connected with a connecting rod 16, the other end of the connecting rod 16 is connected to the moving contact 17 operating mechanism 12, the moving contact 17 operating mechanism 12 is connected to the moving contact 17, the current release 13 is connected to a static contact 18, the zero-sequence current transformer 11 is electrically connected to the current release 13, the static contact 18 is electrically connected to the inlet terminal 14, the moving contact 17 is electrically connected to the outlet terminal 15, the handle 10 rotates and drives the moving contact 17 operating mechanism 12 to realize the connection or disconnection of the moving contact 17 and the static contact 18.
[0028] The implementation principle is: the current state is monitored in real time through the zero-sequence current transformer 11, leakage protection and residual current monitoring are performed on the circuit breaker access current, the induction accuracy is improved, signal interference from other directions can be shielded, and accurate detection can be effectively achieved, with small volume, high precision and strong anti-interference ability; when the zero-sequence current transformer 11 detects current abnormality, the monitoring feedback is applied to the current release 13 in the leakage circuit breaker, so that the current release 13 is electrically connected and drives the moving contact 17 operating mechanism 12 to operate to realize the connection or disconnection of the moving contact 17 and the static contact 18, thereby achieving the leakage protection function of the circuit breaker.
[0029] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A zero-sequence current transformer, comprising a housing (1), characterized in that: The housing (1) is hollow and formed with a U-shaped annular groove, a magnetic core ring (2) is arranged in the U-shaped annular groove, an inner coil (3) for a leakage protection chip is evenly wound around the circumference of the magnetic core ring (2), an insulating ring layer (4) is wound around the circumference of the inner coil (3), an outer coil (5) for a residual current monitoring single chip is evenly wound around the circumference of the insulating ring layer (4), the inner coil (3) is connected to a lead terminal 1 (6), and the outer coil (5) is connected to a lead terminal 2 (7).
2. The zero-sequence current transformer according to claim 1, characterized in that: The inner coil (3) and the outer coil (5) have the same number of winding turns.
3. The zero-sequence current transformer according to claim 1, characterized in that: The gap between the U-shaped annular groove and the outer coil (5) is filled with an epoxy resin glue layer (8).
4. The zero-sequence current transformer according to claim 1, characterized in that: The cross section of the housing (1) is circular.
5. The zero-sequence current transformer according to claim 1, characterized in that: The insulating ring layer (4) is an insulating tape ring layer.
6. A circuit breaker, characterized in that: The invention comprises a housing (9), a handle (10) rotatably mounted on the housing (9), a zero-sequence current transformer (11) as claimed in any one of claims 1 to 5, a moving contact (17) operating mechanism (12) mounted in the housing (9), and a current release (13), wherein the housing (9) is provided with an inlet terminal (14) and an outlet terminal (15) for connecting a wire, the handle (10) is movably connected to a connecting rod (16), and the other end of the connecting rod (16) is connected to the moving contact (17) operating mechanism (12). The movable contact (17) operating mechanism (12) is connected to the movable contact (17), the current release (13) is connected to the stationary contact (18), the zero-sequence current transformer (11) is electrically connected to the current release (13), the stationary contact (18) is electrically connected to the incoming line terminal (14), the movable contact (17) is electrically connected to the outgoing line terminal (15), and the handle (10) is rotated to drive the movable contact (17) operating mechanism (12) to operate so as to realize the connection or disconnection of the movable contact (17) and the stationary contact (18).