Current transformer with spare secondary terminals

Abstract

The present invention discloses a current transformer with spare secondary terminals, which relates to the technical field of electric power equipment, and in particular to a current transformer with spare secondary terminals, which includes: a current transformer body, a terminal block and a conductive sheet; the current transformer of the present invention is provided with multiple wiring terminals on each transformer winding terminal, that is, a spare secondary terminal, and if the secondary terminal screws are lost, the screw holes are unscrewed, and the auxiliary secondary terminals can be directly used if they are burned, which saves time for finding accessories and repairs, saves labor hours, and improves maintenance efficiency. The device of the present invention is provided with a boss, a guide pin and a second screw. Under the pressing force of the second screw, the first conductive sheet and the second conductive sheet are in electrical contact, thereby short-circuiting the secondary terminals of the current transformer to avoid incorrect wiring. When the wiring is completed, the terminals of the current transformer are separated by continuing to tighten the second screw and put into use.

Description

Technical Field

[0001] The invention relates to the technical field of electric power equipment, in particular to a current transformer with a spare secondary terminal. Background Art

[0002] Current transformers are sensors that enable secondary equipment such as measuring instruments and relay protection in power systems to obtain current information from the primary circuit. They are important electrical equipment in power systems and are responsible for isolating high and low voltage systems and converting high voltage quantities to low voltage quantities. Whether the current transformer itself works properly is extremely important to the safety of the power system and the normal operation of protection and measurement equipment.

[0003] The principle of the current transformer is to convert a large current into a small current according to a specified ratio, and then provide the small current converted in the specified ratio to various metering, relay protection and automatic devices. In this process, it isolates the secondary system from the high-voltage equipment, thereby ensuring the safety of personnel and equipment. The secondary side of the current transformer is not allowed to be open during operation. Once the secondary side is open, it will generate extremely high voltage, endangering personal safety, affecting the operation of metering, protection devices and electronic loads, causing secondary insulation breakdown, and causing the magnetic circuit of the current transformer to be oversaturated, the iron core to heat up, and the current transformer to burn out. It may also cause a fire and cause major accidents. Although there are currently many measures to avoid open-circuit accidents, such as power-off operations, or removing the transformer and rewiring, the complexity of the power equipment not being able to be powered off during operation and removing the transformer limits these measures and cannot be well implemented.

[0004] During the installation, replacement and operation of the current transformer, the secondary terminals often have the following problems:

[0005] 1. New workers and interns often drop secondary screws into the transformer box;

[0006] 2. Remove the secondary screws in the screw holes;

[0007] 3. For old substations, the current transformer secondary cannot be short-circuited at the terminal block when adjusting the current transformation ratio during operation;

[0008] 4. The secondary terminal is loosely connected and burned.

[0009] The invention patent of application number 201210449719.4, authorization announcement number CN 103812098 B, titled: Secondary open circuit protection device for current transformer, discloses a secondary open circuit protection device for current transformer. The invention provides a secondary open circuit protection device for current transformer, including an insulating upper cover, a PCB control board and an insulating lower cover. The PCB control board is welded with a load terminal, a normally closed normally open switch, an indicator light and a transformer terminal. The load terminal is connected to a load, and the transformer terminal is connected to a transformer. When the normally closed normally open switch is in the normally closed state, the transformer is directly connected to the load. When the normally closed normally open switch is in the normally open state, the two ends of the transformer are connected. The invention is simple to operate. It only needs to use the normally closed normally open switch to conduct the two ends of the current transformer. After confirming that the two ends of the current transformer are already conducted, the wiring operation of the current transformer can be safely performed.

[0010] The structure adopted in the invention is an electronic structure for preventing the secondary circuit of the current transformer from being opened. The stability of the electronic structure is slightly worse than that of the mechanical structure.

[0011] Application No. 201410444859.1, Authorization Announcement CN 105449655 B, titled as a current transformer secondary open circuit protection method and device invention patent, the invention discloses a current transformer secondary open circuit protection method and device, the method is to monitor the current transformer secondary side circuit voltage, when the secondary side is open circuit, the voltage will become very large, the current transformer secondary side circuit is short-circuited, and the staff is reminded of equipment damage, the device includes a housing, a driving mechanism, a transmission mechanism and a short-circuit mechanism, the driving mechanism is composed of a relay, an electric telescopic rod and a connecting plug, the connecting plug connects the relay to the secondary side of the current transformer, the relay is connected to the electric telescopic rod, the driving mechanism includes a base, the base is provided with a transmission rod through a bracket, the short-circuit mechanism includes a copper plate, a plug is provided under the copper plate, and the copper plate is wrapped with insulating material. The invention uses the technology of relay control circuit, when the voltage changes, the relay starts the telescopic rod to push the transmission rod to insert the short-circuit plug into the secondary side circuit terminal, and the secondary side circuit is short-circuited.

[0012] This invention patent utilizes the high voltage generated when the current transformer is open-circuited to drive a device to short-circuit the secondary side of the current transformer. It cannot guarantee the current transformer open-circuit problem caused by misconnection during wiring. Summary of the invention

[0013] The invention provides a current transformer with a spare secondary terminal, which is used to solve the problem of inconvenience in using the current transformer connection terminal in the prior art.

[0014] The present invention adopts the following technical solution:

[0015] A current transformer with spare secondary terminals, comprising: a current transformer body, a terminal block and a conductive sheet;

[0016] The terminal block is made of insulating material; the conductive sheet is detachably connected to the terminal block;

[0017] The current transformer body comprises a winding, and the winding end is electrically connected to the conductive sheet; the number of the conductive sheets is the same as the number of the winding joints;

[0018] The conductive sheet is provided with at least two terminal mounting holes.

[0019] Further, the terminal block includes: a terminal block body, a boss and a guide pin, the boss is fixedly arranged on the upper surface of the terminal block body, the guide pin is fixedly arranged on the upper surface of the boss; the terminal block body is provided with a second threaded hole;

[0020] The conductive sheet comprises: a second screw, a first conductive sheet and a second conductive sheet; the first conductive sheet is arranged on the upper surface of the terminal block body; the second conductive sheet is an elastic conductive sheet;

[0021] The second conductive sheet is provided with a pin hole and a second mounting hole, the pin hole is loosely matched with the guide pin, and the second screw passes through the second mounting hole and is threadedly connected with the second threaded hole;

[0022] The second conductive sheet is disposed above the first conductive sheet.

[0023] Further, the first conductive sheet includes: a first conductive sheet body and a first contact; the first contact is fixedly arranged at one end of the first conductive sheet body, and the first contact is arranged on the upper surface of the first conductive sheet body;

[0024] The second conductive sheet includes: a second conductive sheet body and a second contact; the second contact is fixedly arranged at one end of the second conductive sheet body, and the second contact is arranged on the lower surface of the second conductive sheet body.

[0025] Furthermore, the height of the boss is smaller than the sum of the thickness of the first conductive sheet body, the thickness of the first contact point, and the thickness of the second contact point.

[0026] Furthermore, the thickness of the second conductive sheet body is smaller than the height of the guide pin.

[0027] Furthermore, the upper surface of the guide pin is provided with a chamfer.

[0028] Furthermore, it also includes: a first screw, the first conductive sheet body is provided with a first mounting hole, the first mounting holes are at least three, the terminal block body is provided with a first threaded hole, the number of the first threaded holes is the same as the number of the first mounting holes, the first screw passes through the first mounting hole, and the first screw is threadedly connected to the first threaded hole.

[0029] Furthermore, the color of the chamfer on the upper surface of the guide pin is different from the color of the guide pin body.

[0030] Furthermore, it also includes: a third screw, the second conductive sheet is provided with a third threaded hole, and the third screw is adapted to the third threaded hole.

[0031] Furthermore, it also includes: a gasket, which is compatible with the first screw, the second screw and the third screw.

[0032] The positive effects of the present invention are as follows:

[0033] A current transformer with spare secondary terminals, comprising: a current transformer body, a terminal row and a conductive sheet;

[0034] The current transformer of the present invention is provided with multiple connection terminals on each transformer winding connection terminal, that is, a spare secondary terminal. If the secondary terminal screw is lost, the screw hole is unscrewed, or it is burned, the auxiliary secondary terminal can be directly used, which saves the time of finding parts and repairing, saves labor hours, and improves the maintenance efficiency. In particular, when the secondary terminal is not connected and burned, the auxiliary terminal is used to avoid the scrapping of the current transformer, which brings convenience to maintenance and adjustment of the conversion ratio.

[0035] The device of the present invention is provided with a boss, a guide pin and a second screw. Under the pressing force of the second screw, the first conductive sheet and the second conductive sheet are in electrical contact, thereby short-circuiting the secondary terminals of the current transformer, avoiding incorrect wiring, resulting in an open circuit of the secondary of the current transformer and burning of the current transformer; the first conductive sheet and the second conductive sheet are both provided with contacts, and the first conductive sheet and the second conductive sheet are in electrical contact through the contacts, with a small contact resistance, thereby ensuring the reliability of the short circuit between the conductive sheets; when the wiring is completed, by continuing to tighten the second screw, the terminals of the current transformer are separated and the device can be put into use, and the separation and short-circuiting methods are simple and easy to use.

[0036] The height of the boss is smaller than the sum of the thickness of the first conductive sheet body, the thickness of the first contact and the thickness of the second contact, so that when the first conductive sheet and the second conductive sheet are electrically contacted, the boss does not provide support for the second conductive sheet; the guide pin is provided with a chamfer to facilitate the guide pin to be threaded into the pin hole, and the chamfer color of the guide pin is different from the body color. The connectivity between the first conductive sheet and the second conductive sheet can be determined by the degree of exposure of the chamfer of the guide pin.

[0037] The current transformer of the present invention is provided with a plurality of wiring terminals, and the wires are tightened by screws, so the contact resistance is small and the wiring method is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a three-dimensional diagram of a terminal block according to an embodiment of the present invention;

[0039] Figure 2 A top view of a terminal block according to an embodiment of the present invention;

[0040] Figure 3 This is a front view of the connection terminal according to an embodiment of the present invention;

[0041] Figure 4 This is a front cross-sectional view of a terminal block according to an embodiment of the present invention;

[0042] Figure 5 This is a three-dimensional diagram of a terminal block according to an embodiment of the present invention.

[0043] In the figure:

[0044] 1. Terminal block body;

[0045] 2 bosses;

[0046] 3 guide pins;

[0047] 4 second threaded hole;

[0048] 5 second screw;

[0049] 6 pin holes;

[0050] 7 second mounting hole;

[0051] 8 a first conductive sheet body;

[0052] 9 first contact point;

[0053] 10 a second conductive sheet body;

[0054] 11 second contact point;

[0055] 12 first screw;

[0056] 13 first mounting hole;

[0057] 14 a first threaded hole;

[0058] 15 third screw;

[0059] 16: a third threaded hole;

[0060] 17 Gaskets. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention.

[0062] like Figure 1-5 As shown, a current transformer with spare secondary terminals comprises: a current transformer with spare secondary terminals comprises: a current transformer body, a terminal block and a conductive sheet;

[0063] The terminal block is made of insulating material; the conductive sheet is detachably connected to the terminal block;

[0064] The current transformer body comprises a winding, and the winding end is electrically connected to the conductive sheet; the number of the conductive sheets is the same as the number of the winding joints;

[0065] The conductive sheet is provided with at least two terminal mounting holes.

[0066] Further, the terminal block comprises: a terminal block body 1, a boss 2 and a guide pin 3, wherein the boss 2 is fixedly arranged on the upper surface of the terminal block body 1, and the guide pin 3 is fixedly arranged on the upper surface of the boss 2; the terminal block body 1 is provided with a second threaded hole 4;

[0067] The conductive sheet comprises: a second screw 5, a first conductive sheet and a second conductive sheet; the first conductive sheet is arranged on the upper surface of the terminal block body 1; the second conductive sheet is an elastic conductive sheet;

[0068] The second conductive sheet is provided with a pin hole 6 and a second mounting hole 7, the pin hole 6 is clearance-matched with the guide pin 3, and the second screw 5 passes through the second mounting hole 7 and is threadedly connected with the second threaded hole 4;

[0069] The second conductive sheet is disposed above the first conductive sheet.

[0070] Furthermore, the first conductive sheet includes: a first conductive sheet body 8 and a first contact 9; the first contact 9 is fixedly arranged at one end of the first conductive sheet body 8, and the first contact 9 is arranged on the upper surface of the first conductive sheet body 8;

[0071] The second conductive sheet includes: a second conductive sheet body 10 and a second contact 11 ; the second contact 11 is fixedly disposed at one end of the second conductive sheet body 10 , and the second contact 11 is disposed on the lower surface of the second conductive sheet body 10 .

[0072] Furthermore, the height of the boss 2 is smaller than the sum of the thickness of the first conductive sheet body 8 , the thickness of the first contact 9 , and the thickness of the second contact 11 .

[0073] Furthermore, the thickness of the second conductive sheet body 10 is smaller than the height of the guide pin 3 .

[0074] Furthermore, the upper surface of the guide pin 3 is chamfered.

[0075] Furthermore, the color of the chamfer on the upper surface of the guide pin 3 is different from the color of the body of the guide pin 3 .

[0076] More specifically, the current transformer of the present invention is provided with multiple connection terminals on each transformer winding connection terminal, that is, a spare secondary terminal is provided. If the screws of the secondary terminals are lost, the screw holes are unscrewed, or they are burned, the auxiliary secondary terminals can be directly used, which saves the time of finding parts and repairs, saves man-hours, and improves the maintenance efficiency. In particular, when the secondary terminals are loosely connected and burned, the auxiliary terminals are used to avoid the scrapping of the current transformer, which brings convenience to maintenance and adjustment of the conversion ratio.

[0077] The present invention also has a function of preventing the secondary circuit of the current transformer from being open. As shown in the figure, under the tightening force of the second screw 5, the second contact 11 of the second conductive sheet first makes electrical contact with the first contact 9 of the first conductive sheet, and the secondary terminal of the current transformer is in a short-circuit state. At this time, it is in a factory standby state.

[0078] When it is necessary to install the wiring, first connect the first conductive sheet. In this embodiment, two first conductive sheets are provided. At this time, the first conductive sheet and the second conductive sheet are always in a short-circuit state. After the first conductive sheet is connected, the second conductive sheet is connected. After the second conductive sheet is connected, the second screw 5 is tightened. Under the tightening force of the second screw 5, the first conductive sheet is elastically deformed, and the center of the second conductive sheet is deformed downward. The peripheral part of the pin hole 6 abuts against the boss 2. The boss 2 serves as a fulcrum, so that the first contact 9 at one end of the first conductive sheet is tilted, and the first contact 9 of the first conductive sheet is separated from the second contact 11 of the second conductive sheet, so as to realize the disconnection between the secondary terminals of the current transformer and complete the wiring.

[0079] When the current transformer needs to be removed, the second screw 5 is loosened, and the first conductive sheet returns to its original shape due to elastic deformation. The first contact 9 of the first conductive sheet contacts the second contact 11 of the second conductive sheet, and the secondary terminals of the current transformer are short-circuited. Then, the wires connected to the first conductive sheet and the second conductive sheet are removed to complete the removal of the current transformer.

[0080] Since the height of the boss 2 is smaller than the sum of the thickness of the first conductive sheet body 8, the thickness of the first contact 9 and the thickness of the second contact 11, at the beginning of the electrical contact between the first contact 9 of the first conductive sheet and the second contact 11 of the second conductive sheet, the periphery of the pin hole 6 of the first conductive sheet does not contact the boss 2, so the two ends of the first conductive sheet do not curl up.

[0081] The thickness of the second conductive sheet body 10 is less than the height of the guide pin 3. In the present embodiment, the sum of the height of the guide pin 3 and the height of the boss 2 is equal to the sum of the thickness of the first conductive sheet body 8, the thickness of the second conductive sheet, the thickness of the first contact 9 and the thickness of the second contact 11. Therefore, at the beginning of the electrical contact between the first contact 9 of the first conductive sheet and the second contact 11 of the second conductive sheet, the upper surface of the guide pin 3 is flush with the upper surface of the second conductive sheet. By determining whether the upper surface of the guide pin 3 is flush with the second conductive sheet, it can be determined whether the first conductive sheet and the second conductive sheet have made electrical contact.

[0082] When the pin hole 6 of the first conductive sheet comes into contact with the boss 2, since the length of the guide pin 3 is greater than the thickness of the second conductive sheet body 10, the guide pin 3 is more exposed than the pin hole 6. In the present embodiment, the guide pin 3 is provided with a chamfer. The chamfer has two functions: it is convenient to insert the pin hole 6 into the guide pin 3. In addition, because the chamfered portion is painted with red paint, when the red paint is more exposed than the second conductive sheet body 10, it indicates that the first contact 9 of the first conductive sheet and the second contact 11 of the second conductive sheet have been separated, and the secondary side of the current transformer has been disconnected.

[0083] The device of the present invention is provided with a boss 2, a guide pin 3 and a second screw 5. Under the pressing force of the second screw 5, the first conductive sheet and the second conductive sheet are in electrical contact, thereby short-circuiting the secondary terminal of the current transformer to avoid incorrect wiring, which causes the secondary circuit of the current transformer to be open and causes the current transformer to burn out; the first conductive sheet and the second conductive sheet are both provided with contacts, and the first conductive sheet and the second conductive sheet are in electrical contact through the contacts, and the contact resistance is small, thereby ensuring the reliability of the short circuit between the conductive sheets; the height of the boss 2 is less than the sum of the thickness of the first conductive sheet body 8, the thickness of the first contact 9 and the thickness of the second contact 11, so that at the beginning of the electrical contact between the first conductive sheet and the second conductive sheet, the boss 2 does not support the second conductive sheet; the guide pin 3 is provided with a chamfer to facilitate the guide pin 3 to be threaded into the pin hole 6, and the chamfer color of the guide pin 3 is different from the body color. The connectivity between the first conductive sheet and the second conductive sheet can be determined by the degree of exposure of the chamfer of the guide pin 3.

[0084] Furthermore, it also includes: a first screw 12, the first conductive sheet body 8 is provided with a first mounting hole 13, the first mounting holes 13 are at least three, the terminal block body 1 is provided with a first threaded hole 14, the number of the first threaded holes 14 is the same as the number of the first mounting holes 13, the first screw 12 passes through the first mounting hole 13, and the first screw 12 is threadedly connected to the first threaded hole 14.

[0085] Furthermore, it also includes: a third screw 15 , the second conductive sheet is provided with a third threaded hole 16 , and the third screw 15 is matched with the third threaded hole 16 .

[0086] Furthermore, it also includes a gasket 17 , and the gasket 17 is matched with the first screw 12 , the second screw 5 and the third screw 15 .

[0087] More specifically, in this embodiment, the first conductive sheet is provided with three first mounting holes 13, and three first threaded holes 14 are provided on the terminal block body 1. The first threaded holes 14 are adapted to the positions of the first mounting holes 13. The first screw 12 presses the first conductive sheet onto the terminal block body 1 through the gasket 17. When wiring, just loosen the first screw 12, press the wire under the gasket 17, and tighten the first screw 12.

[0088] The second conductive sheet is provided with a third threaded hole 16 . When wiring, the wire is pressed under the gasket 17 and then tightened with the third screw 15 .

[0089] The current transformer of the present invention is provided with a plurality of wiring terminals, and the wires are tightened by screws, so the contact resistance is small and the wiring method is simple.

[0090] The above implementations are only preferred embodiments of the present invention, and are not exhaustive of the feasible implementations of the present invention. For those skilled in the art, any obvious changes made to the present invention without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A current transformer with spare secondary terminals, characterized in that: include: Current transformer body, terminal block and conductive sheet; The terminal block is made of insulating material; The conductive sheet is detachably connected to the terminal block; The current transformer body comprises a winding, and the winding end is electrically connected to the conductive sheet; the number of the conductive sheets is the same as the number of the winding joints; The conductive sheet is provided with at least two terminal mounting holes; The terminal block comprises: a terminal block body (1), a boss (2) and a guide pin (3), wherein the boss (2) is fixedly arranged on the upper surface of the terminal block body (1), and the guide pin (3) is fixedly arranged on the upper surface of the boss (2); the terminal block body (1) is provided with a second threaded hole (4); The conductive sheet comprises: a second screw (5), a first conductive sheet and a second conductive sheet; the first conductive sheet is arranged on the upper surface of the terminal block body (1); The second conductive sheet is an elastic conductive sheet; the second conductive sheet is provided with a pin hole (6) and a second mounting hole (7); the pin hole (6) and the guide pin (3) are clearance-matched; the second screw (5) passes through the second mounting hole (7) and is threadedly connected with the second threaded hole (4); The second conductive sheet is disposed above the first conductive sheet; The first conductive sheet comprises: a first conductive sheet body (8) and a first contact (9); the first contact (9) is fixedly arranged at one end of the first conductive sheet body (8), and the first contact (9) is arranged on the upper surface of the first conductive sheet body (8); The second conductive sheet comprises: a second conductive sheet body (10) and a second contact (11); the second contact (11) is fixedly arranged at one end of the second conductive sheet body (10), and the second contact (11) is arranged on the lower surface of the second conductive sheet body (10); The height of the boss (2) is less than the sum of the thickness of the first conductive sheet body (8), the thickness of the first contact (9) and the thickness of the second contact (11); The thickness of the second conductive sheet body (10) is smaller than the height of the guide pin (3); The sum of the height of the guide pin (3) and the height of the boss (2) is equal to the sum of the thickness of the first conductive sheet body (8), the thickness of the second conductive sheet, the thickness of the first contact (9) and the thickness of the second contact (11).

2. The current transformer with spare secondary terminals according to claim 1, characterized in that: The upper surface of the guide pin (3) is provided with a chamfer.

3. The current transformer with spare secondary terminals according to claim 2, characterized in that: Also includes: A first screw (12), the first conductive sheet body (8) is provided with a first mounting hole (13), the number of the first mounting holes (13) is at least three, the terminal block body (1) is provided with a first threaded hole (14), the number of the first threaded holes (14) is the same as the number of the first mounting holes (13), the first screw (12) passes through the first mounting hole (13), and the first screw (12) is threadedly connected to the first threaded hole (14).

4. The current transformer with spare secondary terminals according to claim 3, characterized in that: The color of the chamfer on the upper surface of the guide pin (3) is different from the color of the body of the guide pin (3).

5. The current transformer with spare secondary terminals according to claim 4, characterized in that: Also includes: A third screw (15), the second conductive sheet is provided with a third threaded hole (16), and the third screw (15) is matched with the third threaded hole (16).

6. The current transformer with spare secondary terminals according to claim 5, characterized in that: Also includes: A gasket (17), wherein the gasket (17) is compatible with the first screw (12), the second screw (5) and the third screw (15).

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