Solid insulated ring network cabinet, is the use of solid insulating materials as the main insulating medium of the ring network cabinet, the vacuum interrupter and its conductive connections, isolation switches, grounding switches, main bus and other dominant electrical circuits, single or combination of solid insulating media wrapped and encapsulated into a solid insulating medium with certain functions, and can be combined again and expand the fully insulated, fully sealed module with fully insulated, fully sealed module, the surface accessible to human beings is coated with a conductive or semi-conductive shielding layer, and can be directly and reliably grounded ring network cabinets. The human-accessible surface is coated with conductive or semi-conductive shielding layer, and can be directly and reliably grounded ring network cabinet. As an important part of intelligent distribution network construction, this type of ring main unit meets the requirements of “strong, reliable, intelligent and green” power supply network.
Structure of solid insulation ring main unit
At present, there are a number of enterprises at home and abroad in the research and development of solid insulated ring main unit, some have passed the type test, and around the network operation for several years. From the solid insulated ring network cabinet on the market, it can be seen that the structure of solid insulated ring network cabinet has the following main types:
(1) Solid insulated switch with only main circuit vacuum circuit breaker.
(2) Vacuum circuit breaker + air-insulated three-position isolation and grounding switch.
(3) Vacuum circuit breaker + vacuum three-position isolation and earthing switch.
Characteristics of solid insulated ring main unit
The structural design of solid insulated ring main unit is in line with and adaptable to the requirements of modern strong smart grid, with the main features of full insulation, full sealing, modularization, miniaturization, etc. The main circuit part adopts single-phase modular design. The main circuit part adopts single-phase modular design, which on one hand can completely avoid the occurrence of phase-to-phase short-circuit faults during operation; on the other hand, it greatly improves the maintenance efficiency and reduces the maintenance cost at the same time. Solid insulated ring main unit completely eliminates SF6 gas and the corresponding gas box parts from the principle structure, completely solves the accident caused by the explosion due to the pressure rise when the switch is short-circuited inside the gas box, and completely avoids the emission of harmful gases caused by the decomposition and leakage of SF6 gas, thus it really becomes an environmentally friendly switching product needed by the society.
In addition, solid insulated ring main unit has more outstanding ability to resist harsh environment than SF6 ring main unit, and it is more adaptable and obvious in harsh environment such as cold, plateau, humidity, strong wind and sand, etc. At the same time, solid insulated ring main unit also has the advantage of being able to resist the explosion caused by the pressure rise of SF6. At the same time, solid insulated ring main unit also has on-line testing function for insulation, temperature rise, mechanical characteristics, etc., to meet the requirements of strong intelligent power grid in China.