Intelligent substation CT secondary circuit wiring structure

Abstract

The utility model relates to the technical field of transformer stations, in particular to an intelligent transformer station CT (Current Transformer) secondary circuit wiring structure, which comprises an intelligent control cabinet, a current transformer, a transformer protector and a short lead protector, control cables are fixedly installed between the current transformer, the transformer protector and the corresponding terminal strip, between the short lead protector and the corresponding terminal strip, and one terminal strip is connected with a socket through a wire. Compared with the prior art, the intelligent control cabinet has the advantages that the wiring mode of the CT secondary circuit is optimized in the intelligent control cabinet, the independence of the CT secondary circuit is ensured under the condition that transformer protection and short lead protection share the same CT secondary coil, the function of preventing open-circuit operation of the CT secondary circuit is achieved at the same time, and the service life of the CT secondary circuit is prolonged. The equipment operation safety is effectively improved, the workload of operation and maintenance personnel is reduced, a certain engineering application value is achieved, and the practicability of the scheme is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of substation technology, and in particular to a wiring structure for the secondary circuit of a smart substation CT. Background Technology

[0002] Currently, in 500kV smart substations where short-lead protection is configured within the same string, the transformer protection (or line protection) and short-lead protection share one set of CT secondary coils. The commonly used design scheme in construction drawings is: when both types of protection share one set of CT secondary coils, a series connection design is adopted. After the transformer protection is connected in series with the short-lead protection in the CT secondary circuit, it is as follows: Figure 5 As shown. This design scheme requires comprehensive consideration of the security measures and interrelationships of both types of protection when one type is engaged or disengaged, which increases the complexity of the security measures and is detrimental to the safe operation of the protection. Specifically:

[0003] (1) Transformer maintenance: Turn off transformer protection and turn on short lead protection. At this time, safety measures need to be carried out at the terminal block of short lead protection. Use short connecting pieces to short-circuit the A, B, and C three-phase currents flowing through short lead protection to the common terminal (N phase) to prevent the CT secondary circuit from operating in an open circuit.

[0004] (2) Transformer commissioning: Transformer protection is activated, and short-lead protection is deactivated. Since the transformer protection is connected in series after the short-lead protection in the CT secondary circuit, the short-lead protection is deactivated (the pressure plate is removed, and the device power supply is disconnected) to ensure the normal operation of the transformer protection. However, the short-lead protection remains energized. The status of the short-lead protection has a significant impact on the normal operation of the transformer protection.

[0005] In summary, under the above wiring method, the short lead protection continuously affects the normal operation of the transformer protection, which is not conducive to the safe operation of the protected equipment, and also brings inconvenience to the work of operation and maintenance personnel.

[0006] To address this issue, this utility model proposes a wiring structure for the secondary circuit of a smart substation CT. Utility Model Content

[0007] The purpose of this invention is to at least solve one of the aforementioned technical defects.

[0008] Therefore, one objective of this utility model is to propose a wiring structure for the secondary circuit of a smart substation CT, so as to solve the problems mentioned in the background art and overcome the shortcomings of the existing technology.

[0009] To achieve the above objectives, one embodiment of this utility model provides a wiring structure for the secondary circuit of a smart substation CT, including a smart control cabinet, a current transformer, a transformer protection device, and a short-lead protection device. The smart control cabinet has three terminal blocks fixedly installed inside. Control cables are fixedly installed between the current transformer, the transformer protection device, and the short-lead protection device and their corresponding terminal blocks. One of the terminal blocks is connected to a socket via a wire, and the other two terminal blocks are respectively connected to a first plug and a second plug via wires. Both the first plug and the second plug are inserted into the socket.

[0010] Preferably, in any of the above solutions, a first guide rail is fixedly installed inside the intelligent control cabinet, and a first slider is fixedly installed inside the first guide rail by bolts, with one side of the socket fixedly installed on one side of the first slider.

[0011] Preferably, in any of the above solutions, a second guide rail is fixedly installed inside the intelligent control cabinet, and two second sliders are fixedly installed inside the second guide rail by bolts. Each of the two second sliders has a hook fixedly installed on it, and the first plug and the second plug are respectively suspended on the corresponding hooks.

[0012] The technical effect achieved by adopting the above solution is: to facilitate the installation of sockets, first plugs, and second plugs.

[0013] Preferably, the socket is an anti-open-circuit type socket, which is one of the above solutions.

[0014] Preferably, in any of the above solutions, both the first plug and the second plug are open-circuit resistant plugs that are compatible with the socket.

[0015] The technical effect achieved by adopting the above solution is to prevent the plug from detaching.

[0016] Preferably, the control cable is of model ZC-KVVP2-22, which is one of the above-mentioned options.

[0017] Preferably, in any of the above solutions, the first plug is connected to the transformer protection via wires, terminal blocks, and control cables.

[0018] Preferably, in any of the above solutions, the second plug is connected to the short lead protection via wires, terminal blocks, and control cables.

[0019] The technical effect achieved by adopting the above solution is: convenient switching.

[0020] Preferably, one side of the socket is fixedly fitted with a first insulating protective cover, and one side of the first insulating protective cover is sleeved on the outside of the socket.

[0021] The technical effect achieved by adopting the above solution is to protect the socket and improve safety.

[0022] Preferably, one side of each of the first and second plugs is fixedly fitted with a second insulating protective cover, and one side of each of the two second insulating protective covers is respectively fitted onto the outside of the first and second plugs.

[0023] The technical effect achieved by adopting the above solution is to protect the plug and improve safety.

[0024] Compared with the prior art, the advantages and beneficial effects of this utility model are as follows:

[0025] This utility model optimizes the wiring method of the CT secondary circuit in the intelligent control cabinet, ensuring the independence of the CT secondary circuit when the transformer protection and short lead protection share the same CT secondary coil. At the same time, it realizes the CT secondary circuit anti-open circuit operation function. Through the independent anti-open circuit socket and matching plug, it solves the adverse effects of protection activation / deactivation caused by the shortcomings of the wiring scheme of the two types of protection sharing the CT secondary coil. It effectively improves the safety of equipment operation and reduces the workload of operation and maintenance personnel, has certain engineering application value, and ensures the practicality of the solution.

[0026] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0028] Figure 1 This is a structural schematic diagram of the first state according to an embodiment of the present utility model;

[0029] Figure 2 This is a structural schematic diagram of the second state according to an embodiment of the present utility model;

[0030] Figure 3 This is a structural schematic diagram of the third state according to an embodiment of the present utility model;

[0031] Figure 4 This is a schematic diagram of the arrangement of the socket, the first plug, and the second plug in the intelligent control cabinet according to an embodiment of the present utility model;

[0032] Figure 5 This is a schematic diagram of the secondary circuit wiring structure of a current transformer (CT) in an existing 500kV substation.

[0033] In the diagram: Note 1, terminal block; Note 2, control cable; Note 3, socket; Note 4, first plug; Note 5, second plug. Detailed Implementation

[0034] Example: Figures 1 to 4 As shown, a secondary circuit wiring structure for a current transformer (CT) in an intelligent substation includes an intelligent control cabinet, a current transformer, transformer protection, and short-lead protection (known technology). Three terminal blocks (known technology) are fixedly installed inside the intelligent control cabinet. Control cables (known technology) are fixedly installed between the current transformer, transformer protection, and short-lead protection and their corresponding terminal blocks. One terminal block is connected to a socket via a wire, and the other two terminal blocks are connected to a first plug and a second plug via wires, respectively. The wire type is the same as the control cable type. Both the first plug and the second plug are inserted into the socket. (Refer to...) Figure 1 The wires connecting the socket, the first plug, and the second plug are all connected to the inner side of the corresponding terminal block in the intelligent control cabinet. The secondary coil of the current transformer, the transformer protection, and the short lead protection are all connected to the outer side of the corresponding terminal block in the intelligent control cabinet through the control cable. This scheme can realize the independence of the CT secondary circuit when the two types of protection are put into operation, and realize the anti-open circuit function of the CT secondary circuit when the current access is switched.

[0035] The intelligent control cabinet has a first guide rail fixedly installed inside, and a first slider is fixedly installed inside the first guide rail by bolts. One side of the socket is fixedly installed on one side of the first slider.

[0036] The intelligent control cabinet has a second guide rail fixedly installed inside. Inside the second guide rail, two second sliders are fixedly installed by bolts. Each of the two second sliders has a hook fixedly installed. The first plug and the second plug are respectively suspended on the corresponding hooks. The hooks provide a place for the first plug and the second plug to avoid random placement. The structure of the first slider, the second slider, and the hooks is not shown in the figure. However, since the technology is mature and no other structural modifications have been made to the intelligent control cabinet, those skilled in the art can implement it in conjunction with the existing technology.

[0037] The socket is an anti-opening type socket.

[0038] Both the first and second plugs are open-circuit resistant plugs that are compatible with the socket. Using open-circuit resistant plugs and sockets can prevent the plugs and sockets from falling off due to non-human causes after connection. This is common technology, and technicians can implement the solution accordingly.

[0039] The control cable model is ZC-KVVP2-22.

[0040] The first plug is connected to the transformer protection via wires, terminal blocks, and control cables.

[0041] The second plug is connected to the short lead protection via wires, terminal blocks, and control cables. The convenience of switching can be improved by using the first and second plugs in conjunction with the socket.

[0042] A first insulating protective cover is fixedly installed on one side of the socket. One side of the first insulating protective cover is fitted onto the outside of the socket, which can provide shielding protection when the socket is not in use.

[0043] A second insulating protective cover is fixedly installed on one side of both the first plug and the second plug. One side of each second insulating protective cover is fitted onto the outside of the first plug and the second plug, respectively, so as to provide shielding and protection when the first plug and the second plug are not in use.

[0044] Since the short lead protection and transformer protection in the secondary circuit wiring will not be put into operation at the same time, the polarity end and common section of the CT secondary coil are led to the terminal block of the intelligent control cabinet through the cable. Each three-phase CT secondary circuit requires a 6-core cable. The number of cable cores is small and easy to implement. Therefore, the transformer protection and short lead protection of this utility model can independently meet the wiring requirements of the CT secondary coil for 500kV intelligent substation protection when sharing the same CT secondary coil.

[0045] The electrical components provided by this utility model are only used in accordance with the structural features of the product in this technical solution. The product will be adjusted and modified after purchase to better match and conform to the technical solution of this utility model. It is an optimal application of this technical solution. The product model can be replaced and modified according to the required technical parameters. It is well known to those skilled in the art. Therefore, those skilled in the art can clearly obtain the corresponding usage effect through the technical solution provided by this utility model.

[0046] A wiring structure for the secondary circuit of a smart substation CT, the working principle of which is as follows:

[0047] 1) When neither type of protection is activated, the current transformer A / B / C phases inside the socket are kept short-circuited to the common terminal and grounded to ensure the secondary circuit of the CT is in a non-disconnected state. The socket is sealed with a first insulating protective cover, and the first and second plugs are sealed with a second insulating protective cover. Figure 1 As shown;

[0048] 2) When the transformer protection is engaged and the short-lead protection is disengaged, the first plug is connected to the socket, the current transformer A / B / C phases are disconnected from the common terminal, the transformer protection collects the current, and the second plug is sealed with the second insulating protective cover. Figure 2 As shown;

[0049] 3) When the short-lead protection is engaged and the transformer protection is disengaged, the second plug is connected to the socket, the current transformer A / B / C phases are disconnected from the common terminal, the short-lead protection collects the current, and the first plug is sealed with the second insulating protective cover. Figure 3 As shown.

[0050] Compared with the prior art, the present invention has the following advantages:

[0051] This utility model optimizes the wiring method of the CT secondary circuit in the intelligent control cabinet, ensuring the independence of the CT secondary circuit when the transformer protection and short lead protection share the same CT secondary coil. At the same time, it realizes the CT secondary circuit anti-open circuit operation function. Through the independent anti-open circuit socket and matching plug, it solves the adverse effects of protection activation / deactivation caused by the shortcomings of the wiring scheme of the two types of protection sharing the CT secondary coil. It effectively improves the safety of equipment operation and reduces the workload of operation and maintenance personnel, has certain engineering application value, and ensures the practicality of the solution.

Claims

1. A wiring structure for the secondary circuit of a CT in an intelligent substation, characterized in that: Intelligent control cabinet, current transformer, transformer protection and short lead protection are included, three terminal rows are fixedly installed in the interior of the intelligent control cabinet, control cables are fixedly installed between the current transformer, transformer protection and short lead protection and corresponding terminal rows, one of the terminal rows is connected with a socket through a wire, the other two terminal rows are respectively connected with a first plug and a second plug through wires, and the first plug and the second plug are inserted into the interior of the socket. 2.The CT secondary circuit wiring structure of a smart substation according to claim 1, wherein: A first guide rail is fixedly installed in the interior of the intelligent control cabinet, a first sliding block is fixedly installed in the interior of the first guide rail through bolts, and one side of the socket is fixedly installed on one side of the first sliding block. 3.The CT secondary circuit wiring structure of a smart substation according to claim 2, characterized in that: A second guide rail is fixedly installed in the interior of the intelligent control cabinet, two second sliding blocks are fixedly installed in the interior of the second guide rail through bolts, a hook is fixedly installed on each of the two second sliding blocks, and the first plug and the second plug are respectively hung on corresponding hooks. 4.The CT secondary circuit wiring structure of a smart substation of claim 3, wherein: The socket is a closed-type socket. 5.The CT secondary circuit wiring structure of a smart substation of claim 4, wherein: The first plug and the second plug are closed-type plugs matched with the socket. 6.The CT secondary circuit wiring structure of a smart substation of claim 5, wherein: The control cable is ZC-KVVP2-22. 7.The CT secondary circuit wiring structure of a smart substation of claim 6, wherein: The first plug is connected with the transformer protection through a wire, a terminal row and a control cable. 8.The CT secondary circuit wiring structure of a smart substation of claim 7, wherein: The second plug is connected with the short lead protection through a wire, a terminal row and a control cable. 9.The CT secondary circuit wiring structure of a smart substation of claim 8, wherein: A first insulation protective cover is fixedly installed on one side of the socket, and one side of the first insulation protective cover is sleeved with the exterior of the socket. 10.The CT secondary circuit wiring structure of a smart substation of claim 9, wherein: A second insulation protective cover is fixedly installed on one side of the first plug and the second plug, and one side of the two second insulation protective covers is respectively sleeved with the exterior of the first plug and the second plug.

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