Zero-sequence mutual inductor and circuit breaker
By designing a zero-sequence transformer of the rectangular shell, adding shielding sheets and adjustment holes, the problem of existing zero-sequence transformers malfunctioning in the face of electromagnetic interference is solved, and anti-interference ability and production efficiency are improved.
Patent Information
- Application Number
- CN202421957912.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-14
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-08-14
AI Technical Summary
Existing zero-sequence transformers are prone to misjudgment in the face of electromagnetic interference, resulting in malfunction of leakage modules, affecting production and life. At the same time, increasing the area of the shielding layer will lead to an increase in volume, blocking the adjustment screws of the double gold sheets, and reducing production efficiency.
A zero-sequence transformer for a rectangular shell is designed to increase the shielding sheet and potted with epoxy resin to increase the anti-interference ability. At the same time, an adjustment hole is provided above the shell to ensure that the adjustment of the double gold sheet is not affected.
The anti-interference ability of the zero-sequence transformer is improved, the occurrence of malfunctions is reduced, and the normal adjustment of the double gold sheet is ensured, and the production efficiency is improved.
Smart Images
Figure CN222965901U_ABST
Abstract
Description
Technical Field
[0001] The utility model specifically relates to a zero-sequence current transformer and a circuit breaker. Background Art
[0002] As one of the main components in a leakage circuit breaker, the zero-sequence current transformer is embedded in the leakage circuit breaker housing or assembled outside the leakage circuit breaker housing. When a certain degree of dangerous leakage current value appears in the protected circuit, the leakage circuit breaker will quickly trip and cut off the power supply to achieve the protection purpose. Currently, the zero-sequence current transformer is in a ring shape, mainly composed of a ring-shaped iron core, an enameled wire coil and a housing. At the same time, the bus bar in the leakage circuit breaker has to pass through the inner circle of the ring-shaped zero-sequence current transformer to obtain the sampling signal.
[0003] It is often affected by electromagnetic interference caused by the impact of normal large current in the circuit, resulting in misjudgment of the detection coil, causing misoperation of the leakage module, and affecting production and life. Since it is installed on the base of the leakage circuit breaker in a vertically inserted manner, if the area of the shielding layer is increased to improve its anti-interference ability, for a leakage circuit breaker with a bimetal strip, after being installed inside the circuit breaker, its volume increase will block the adjustment screw of the front bimetal strip, reducing the production efficiency. Summary of the Utility Model
[0004] Aiming at the deficiencies of the prior art, the purpose of the utility model is to provide a zero-sequence current transformer and a circuit breaker.
[0005] To achieve the above purpose, the utility model provides the following technical solutions:
[0006] A zero-sequence current transformer, comprising:
[0007] A rectangular housing, with a groove on one side and an annular sleeve for a connection plate to pass through at its central position;
[0008] A coil, sleeved outside the annular sleeve and placed in the groove;
[0009] A shielding sheet for covering the coil, and the coil and the shielding sheet are potted in the groove with epoxy resin. The upper side of the rectangular housing is provided with first through holes for adjusting the bimetal strip at both ends.
[0010] The upper end of the rectangular housing is provided with a wire groove communicating with the groove.
[0011] One side or both sides of the wire groove are provided with first wire harness buckles.
[0012] One side of the rectangular housing is provided with a plurality of second wire harness buckles arranged along the height direction of the rectangular housing.
[0013] The other side of the rectangular housing is provided with an extension part.
[0014] A detachable plug is provided in the second through hole of the annular sleeve, and the plug can divide the second through hole into several independent channels.
[0015] The plug includes a central blocking member. A first side and a second side are respectively provided on both sides of the central blocking member. A third side is provided on the upper side of the central blocking member. Isolation members extending outward are provided at the rear ends of the first side, the second side, and the third side. A B-phase channel for the B-phase connection plate to pass through is formed between the lower side of the central blocking member and the inner wall of the second through hole. An A-phase channel for the A-phase connection plate to pass through is formed between the first side and the inner wall of the second through hole. A C-phase channel for the C-phase connection plate to pass through is formed between the second side and the inner wall of the second through hole. An N-pole channel for the N-pole connection plate to pass through is formed between the third side and the inner wall of the second through hole, and the rear ends of the A-phase connection plate, the C-phase connection plate, and the N-pole connection plate are all bent along the extension direction of the isolation member and extend out of the second through hole.
[0016] A baffle is provided at the upper end of the third side.
[0017] A circuit breaker includes a base, a middle cover, and an upper cover. The above-mentioned zero-sequence current transformer is inserted in the base.
[0018] A notch adapted to the wire groove is provided on the middle cover. The wire groove of the zero-sequence current transformer is connected to the notch of the middle cover to form a closed interface.
[0019] Advantages of the present utility model: The shape of the zero-sequence current transformer is adjusted from the original circular shape to a square (similar to a rectangle) transformer, and openings are provided above the left and right sides thereof to achieve a triangular relief hole feature, which is convenient for adjusting the double-metal thermal bending through the two holes during production, and while increasing the shielding effect of the transformer, it does not prevent the production from adjusting the double metal. Description of the Drawings
[0020] Figure 1 It is a schematic structural diagram of the zero-sequence current transformer of the present utility model.
[0021] Figure 2 It is a schematic diagram of the cooperation between the zero-sequence current transformer and the plug of the present utility model.
[0022] Figure 3 It is a schematic structural diagram of the plug.
[0023] Figure 4 It is a schematic diagram of the cooperation between the zero-sequence current transformer and each connection plate of the present utility model.
[0024] Figure 5 It is a schematic structural diagram of the zero-sequence current transformer of the present utility model when cooperating with the connection plate and the double-metal sheet.
[0025] Figure 6 This is the front view when the zero-sequence current transformer of the present utility model is matched with the connection plate and the double metal sheet.
[0026] Figure 7 This is the structural schematic diagram of the circuit breaker disclosed by the present utility model.
[0027] Figure 8 This is the structural schematic diagram of the circuit breaker with the upper cover hidden.
[0028] Figure 9 It is Figure 8 The enlarged schematic diagram at position A in
[0029] Figure 10 This is the matching schematic diagram of the zero-sequence current transformer and the base. Specific embodiments
[0030] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.
[0031] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.
[0032] As Figure 1 shown, a zero-sequence current transformer is composed of a rectangular housing, a coil and a shielding sheet. The coil and the shielding sheet are fixed in the groove of the rectangular housing by means of epoxy resin potting to form an integral body. Figure 1 In
[0033] The rectangular housing 100 has a groove on one side, and an annular sleeve 110 for the connection plate to pass through is provided at the center position. Both ends of the annular sleeve are provided with openings, and the middle is a channel, so that the connection plate can directly pass through the annular sleeve. At the same time, the height of the tube wall is the same as the depth of the groove, which can prevent the epoxy resin from flowing out from this place.
[0034] It is designed to be rectangular, preferably rectangular, so as to increase the size of the needle zero-sequence current transformer and improve its anti-interference ability.
[0035] A coil is sleeved outside the annular sleeve 110 and placed in the groove. This coil is a zero-sequence coil, which has an annular structure and is sleeved around the entire periphery of the annular sleeve.
[0036] A shielding sheet 200 is used to cover the coil. The shielding sheet is made of silicon steel, and its contour is adapted to the overall contour of the groove, so that it can be completely embedded in the groove and block the entire opening of the groove, improving the anti-interference ability.
[0037] As Figure 6 shown, at the same time, in order to avoid the adjustment of the double metal sheets of the original zero-sequence current transformer for phases A and C being blocked due to the increase in volume, first through holes 120 for adjusting the double metal sheets 300 are provided at both ends of the upper side of the rectangular housing 100. The first through holes are designed in a triangular shape, and the double metal sheets 800 for phases A and C located at the rear side thereof can be directly adjusted through the first through holes.
[0038] While achieving an increase in anti-interference ability, it will not affect the normal adjustment function of the double metal sheets for phases A and C.
[0039] A wire groove 130 communicating with the groove is provided at the upper end of the rectangular housing 100. With the design of the wire groove, after the circuit breaker is installed, it will be in contact with the bottom of the middle cover, so that the wire groove and the notch on the middle cover form a closed interface. The power line or the zero-sequence signal line directly passes through the middle cover from here and is connected to the circuit board located inside the middle cover, ensuring electrical isolation.
[0040] First wire harness buckles 150 are provided on any one side or both sides of the wire groove 130. The first wire harness buckles are L-shaped buckles, which are used to directly press the wire harness against the outer wall of the housing, eliminating the need for tying and fixing with cable ties in existing products.
[0041] The first wire harness buckles can be provided on any one side of the wire groove or on both sides, and are set according to the requirements of internal wire routing.
[0042] A plurality of second wire harness buckles 140 are provided on one side of the rectangular housing 100 along the height direction of the rectangular housing 100. Taking the Figure 1 vertical direction in as the height direction, the second wire harness buckles extend upward along the side wall of the rectangular housing. They are used to fix the wire routing of other components, so that the wire harness can travel closely along the surface of the zero-sequence current transformer, ensuring clean and simple internal wire routing. At the same time, the design of multiple second wire harness buckles can guide the wire harness to travel upward.
[0043] On the other side of the rectangular housing 100, there is an extension part 160. The extension part is a structure integrally formed on one side of the rectangular housing. After it is inserted into the circuit breaker housing, it fits against the cavity wall of the N pole of the circuit breaker housing, playing a blocking role, forming a front and rear isolation baffle, increasing a certain degree of sealing, effectively isolating the front and rear ends of the circuit breaker, and preventing fine particles of short - circuit faults and harmful electric arcs from entering the rear - end conductive components.
[0044] As Figure 2 shown, a detachable plug - in part 300 is provided in the second through - hole 170 of the annular sleeve 110. The plug - in part 300 can divide the second through - hole 170 into several independent channels. The existence of this plug - in part can make the connection plates passing through the second through - hole independent of each other and not interfere with each other. Furthermore, the step of winding tape on the connection plates can be omitted, which is more convenient in production. At the same time, it also blocks the second channel as much as possible, effectively isolating the front and rear ends of the circuit breaker, and preventing fine particles of short - circuit faults and harmful electric arcs from entering the rear - end conductive components.
[0045] As Figure 3 、 Figure 4 and Figure 5 shown, the plug - in part 300 includes a central blocking part 310. On both sides of the central blocking part 310, there are a first side edge 320 and a second side edge 330 respectively. On the upper side of the central blocking part 310, there is a third side edge 340. At the rear ends of the first side edge 320, the second side edge 330 and the third side edge 340, there are isolation parts 350 extending outward. A B - phase channel for the B - phase connection plate 500 to pass through is formed between the lower side of the central blocking part 310 and the inner wall of the second through - hole 170. An A - phase channel for the A - phase connection plate 400 to pass through is formed between the first side edge 320 and the inner wall of the second through - hole 170. A C - phase channel for the C - phase connection plate 600 to pass through is formed between the second side edge 330 and the inner wall of the second through - hole 170. An N - pole channel for the N - pole connection plate 700 to pass through is formed between the third side edge 340 and the inner wall of the second through - hole 170. And the rear ends of the A - phase connection plate 400, the C - phase connection plate 600 and the N - pole connection plate 700 are bent along the extending direction of the isolation part 350 and extend out of the second through - hole 170.
[0046] At the same time, on the edges of the first side edge, the second side edge and the isolation part, there are side walls adapted to the thickness of the connection plates, which play a role in wrapping each connection plate and further improving the isolation effect between each connection plate.
[0047] As Figure 6 shown, the sizes of each channel are adapted to the sizes of the connection plates, which can minimize the possibility of front - to - back penetration as much as possible. At the same time, the design of the isolation part at the rear end combined with the central blocking part completely realizes the non - penetration design between the front and the back.
[0048] A baffle 360 is provided at the upper end of the third side 340, and the baffle 360 also has a certain function of restricting the N-pole connection plate.
[0049] As Figure 7 , Figure 8 and Figure 10 shown, the present utility model also discloses a circuit breaker, which includes a base 10, a middle cover 20 and an upper cover 30, and the above-mentioned zero-sequence current transformer 40 is inserted in the base.
[0050] As Figure 9 shown, a notch 21 adapted to the wire groove is provided on the middle cover, and the wire groove 130 of the zero-sequence current transformer is connected to the notch 21 of the middle cover to form a closed interface, that is, the outer edge of the upper surface of the wire groove is in contact with the bottom surface at the notch of the middle cover to form an enclosing sealing structure, so that the notch at this place is not directly communicated with the chamber of the base, ensuring electrical isolation.
[0051] At the same time, as Figure 10 described, after the zero-sequence current transformer is inserted into the base, one end is a wire routing space, and the other end is in contact with the chamber wall to form an isolation baffle for sealing the front and rear ends.
[0052] The embodiments should not be regarded as a limitation of the present utility model, but any improvement based on the spirit of the present utility model should be within the protection scope of the present utility model.
Claims
1. A zero-sequence mutual inductor, characterized in that: It includes: A rectangular shell (100) having a groove on one side and an annular sleeve (110) at the center thereof through which a connecting plate can pass; A coil, sleeved on the outside of the annular sleeve (110) and placed in the groove; The shielding sheet (200) is used to cover the coil, and the coil and the shielding sheet are encapsulated in the groove by epoxy resin. The upper ends of the rectangular housing (100) are provided with first through holes (120) capable of adjusting the double gold sheet (800).
2. A zero-sequence mutual inductor according to claim 1, characterized in that: The upper end of the rectangular housing (100) is provided with a wire groove (130) communicating with the groove.
3. A zero-sequence mutual inductor according to claim 2, characterized in that: A first wire harness buckle (150) is provided on any one side or both sides of the wire slot (130).
4. A zero-sequence mutual inductor according to claim 1, characterized in that: A plurality of second wiring harness buckles (140) arranged along the height direction of the rectangular housing (100) are provided on one side of the rectangular housing (100).
5. A zero-sequence mutual inductor according to claim 1, characterized in that: An extension portion (160) is provided on the other side of the rectangular housing (100).
6. A zero-sequence mutual inductor according to claim 1, characterized in that: A detachable plug-in unit (300) is provided in the second through hole (170) of the annular sleeve (110), and the plug-in unit (300) can separate the second through hole (170) into a plurality of independent channels.
7. A zero-sequence mutual inductor according to claim 6, characterized in that: The plug-in unit (300) comprises a central blocking piece (310), wherein a first side edge (320) and a second side edge (330) are respectively provided on both sides of the central blocking piece (310), and a third side edge (340) is provided on the upper side of the central blocking piece (310). The first side edge (320), the second side edge (330) and the rear ends of the third side edge (340) are all provided with an isolating piece (350) extending outwards. A B-phase passage for allowing a B-phase connecting plate (500) to pass through is formed between the lower side of the central blocking piece (310) and the inner wall of the second through hole (170). The first side edge (320) An A-phase channel is formed between the second side edge (330) and the inner wall of the second through hole (170) through which the A-phase connecting plate (400) can pass; a C-phase channel is formed between the second side edge (330) and the inner wall of the second through hole (170) through which the C-phase connecting plate (600) can pass; an N-pole channel is formed between the third side edge (340) and the inner wall of the second through hole (170) through which the N-pole connecting plate (700) can pass; and rear ends of the A-phase connecting plate (400), the C-phase connecting plate (600) and the N-pole connecting plate (700) are all bent along the extension direction of the isolation piece (350) and extend out of the second through hole (170).
8. A zero-sequence mutual inductor according to claim 7, characterized in that: A baffle (360) is provided at the upper end of the third side edge (340).
9. A circuit breaker, characterized in that: It comprises a base (10), a middle cover (20) and an upper cover (30), wherein the base is plugged with the zero-sequence mutual inductor according to any one of claims 1 to 8.
10. The circuit breaker according to claim 9, characterized in that The middle cover is provided with a notch (21) adapted to the wire slot, and the wire slot (130) of the zero-sequence transformer is connected to the notch (21) of the middle cover to form a closed interface.