Solid cabinet suitable for Inner Mongolia
Solid Insulated Ring Main Units are ring main units that use solid insulation materials as the main insulation medium.
Vacuum arc extinguishing chambers and their conductive connections, isolating switches, grounding switches, main busbars, branch busbars, and other main electrical circuits are individually or combined and encapsulated with solid insulating media to form one or several modules with certain functions, which can be combined or expanded again and have full insulation and sealing performance. The surface of the modules that can be touched by humans is coated with conductive or semi conductive shielding layers and can be directly connected to grounded ring main units.
pros and cons
Compared with gas insulated ring main units, it has its own advantages and disadvantages:
1) No gas leakage or greenhouse effect risk, good environmental performance, maintenance free;
2) The fully sealed insulation structure of epoxy resin integral casting has reliable insulation performance and strong environmental adaptability;
3) Modular design, small size, flexible product, conducive to on-site assembly; For remote areas with poor road traffic conditions, transportation can be separated and then assembled to diversify transportation and installation methods;
4) Emerging products with high costs and inadequate supporting facilities;
5) Immature production process and high scrap rate;
6) The intelligent monitoring technology is not mature, and the effectiveness of the detection results still needs improvement.
Typical network cabinet
Neng Electric, a typical solid insulated ring main unit, is one of the earliest enterprises in China to conduct research on solid insulated ring main units. After years of effort, the company has developed two products, corresponding to two major factions: ① The first generation of solid cabinet main circuits were vacuum circuit breakers or vacuum load switches+vacuum insulated isolation/grounding switches; ② The main circuit of the second-generation solid cabinet is a vacuum circuit breaker or vacuum load switch+an air insulated isolation/grounding switch with a visible break.
The advantages mainly include: ① The product is harmonious with the environment, the main circuit is insulated with solid materials, and the isolation and grounding three position switch is insulated with solid insulation or air insulation. The whole cabinet does not use SF6 gas, does not produce temperature rise gas, and does not damage the ozone layer; ② The application of high-performance epoxy resin materials can simplify the main circuit structure and achieve miniaturization and lightweighting; ③ Simplified operating mechanism design and modular product design, with fewer parts, eliminating gas pressure monitoring during the lifecycle, reducing maintenance, and even eliminating maintenance.
1. Characteristics of the first generation solid cabinet technology
The main structure of the first generation solid cabinet of Zhongneng Electric is a second-generation product, which is a vacuum circuit breaker or vacuum load switch+vacuum insulated isolation/grounding switch structure.
The VSS-12 first generation product is based on the current solid sealing and vacuum insulation technology. It uses epoxy resin (APG process) to separate the vacuum arc extinguishing chamber of the circuit breaker/load switch and the three station vacuum arc extinguishing chamber into epoxy resin material, and connects them together through a conductive component to form a single-phase switch unit. Finally, it is assembled with insulation connectors such as insulated busbars to form a fully insulated, fully enclosed, and anti condensation solid insulated ring network switchgear. The sealing design of the solid switch is an integral casting fully enclosed design, which can achieve a protection level of IP67 for the solid switch and ensure that the product performance is not affected by external environmental changes. The switch structure is designed with phase separation, thereby having the ability to avoid phase to phase short circuits.
2. Technical characteristics of second-generation solid cabinet
The main structure of the second-generation solid cabinet of Zhongneng Electric is a first generation product, which is a vacuum circuit breaker or vacuum load switch+air insulated isolation/grounding switch structure.
Compared with the first generation solid cabinet, its structural feature is the use of solid insulation materials to pour the vacuum arc extinguishing chamber of the three-phase circuit breaker into the shell. The three position switch (isolation, grounding) adopts a coaxial knife switch rotating structure and has an observation window, which can directly observe the isolation fracture, making electricity safer and more reliable.
The problem solved by folding editing in this paragraph
1. Insulation shielding technology and insulation surface spraying technology
Due to the direct impact of the shielding effect of the main switch unit on the performance of the equipment, solid insulated ring main units are particularly evident in this regard. Therefore, in practical design and production, it is necessary to solve the surface shielding technology, that is, the surface metallization of the insulation material. The purpose is to better ground the solid switch unit, reduce the impact of environmental factors on the product, and improve the range of use of solid cabinets. A large part of the solid insulated ring main unit insulation components on the market have not been treated on the surface, resulting in high partial discharge indicators for the products.
2. The issue of 'false fracture'
The current gas insulated isolation switch and grounding switch essentially install the conductive components at both ends of the isolation (grounding) fracture on the same insulation component. In the past, this type of fracture was often referred to as a 'false fracture'. When the isolation switch is in the open state, the insulation performance between the conductive parts of the fracture is jointly affected by the gas between the fracture surfaces and the surface climbing of the supporting insulation parts. Similarly, solid insulated ring main units also have this problem, so electric field analysis and optimization should be carried out on the 'false fracture' during design, and effective technical means should be adopted to make the electric field of the product more uniform and reduce the electric field strength during product operation.
3. Lack of experience in operation and maintenance
Solid insulated ring main unit is a new technology product launched in recent years. However, there was no scientific and reasonable layout design for the trial operation of the hanging network in the early stage, resulting in a small number of hanging network operations and a relatively short cumulative operation time. The provinces and regions where hanging network operations are carried out are not comprehensive enough. For example, in high-altitude and cold areas, high-temperature and humid areas, coastal areas, and areas with frequent rainfall and large temperature differences between day and night, it is necessary to comprehensively accumulate operational experience from different regions across the country. Based on the problems that arise during actual use, targeted and forward-looking improvements should be made to solid insulated ring main units in order to continuously improve product safety and stability.

This intelligence has the characteristics of simple structure, flexible operation, reliable interlocking, and easy installation. It can provide satisfactory technical solutions for various application scenarios and users biography

The adoption of sensing technology, automatic control technology, and information technology, combined with *'s technical performance and simple and flexible assembly solutions, can meet the constantly changing needs of the market and meet the requirements of intelligent power grid.

This ring main unit is suitable for 50HZ, 12 kV power systems and is widely used in industrial and civil cable ring networks and distribution network terminal projects

As a means of receiving and distributing electrical energy, it is suitable for use in urban residential areas, small secondary substations, switch stations, cable branch boxes, box type substations, industrial and mining enterprises, shopping malls, airports, subways, wind power generation, hospitals, sports stadiums, railways, tunnels and other places

Due to its advantages of full insulation, full sealing, and full shielding, this product is particularly suitable for use in areas with harsh environmental conditions such as high altitude, high temperature, humidity, extreme cold, and severe pollution

Solid cabinet suitable for Inner Mongolia

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