66kv side GIS (gas insulated switchgear) structure of 500kv main transformer

Abstract

The invention relates to a 66kv side GIS (gas insulated switchgear) structure of a 500kv main transformer, which comprises a triangular bus, the triangular bus is connected with a main loop which is connected with all branched loops through a 66kv bus, and the triangular bus, the 66kv bus, the main loop and primary equipment in each branched loop are integrated into GIS equipment; and the main loop consists of a main loop isolation switch and a main loop current transformer connected with the main loop isolation switch. GIS has smallest floor area, and a transformer substation is also arranged regularly and orderly. Simultaneously, as the GIS structure is provided with the main loop without a main breaker, the GIS structure has the following two advantages that (1) the current transformer of the main loop is reserved so that the GIS structure has complete and clear relay protection configuration; and (2) the main loop isolation switch is reserved so that certain running flexibility is provided. When equipment is overhauled, the isolation switches of the main loop and the branched loops can be simultaneously turned on, the GIS structure performs equipment maintenance and overhauling under a condition that the two pole isolation switches are turned on, and a main transformer keeps running continuously.

Description

technical field [0001] The invention relates to a GIS structure on the 66kv side of a 500kv main transformer. Background technique [0002] The 66kv side of the 500kv main transformer is designed with Ais, that is, an open power distribution device, and its general circuit is composed of an isolating switch, a general circuit breaker and a current transformer. So far, almost all 500kv substations use AIS power distribution devices on the low-voltage side of the main transformer, which are generally supported tubular busbars, and are equipped with conventional transformers such as porcelain column / tank circuit breakers, disconnectors, current transformers, voltage transformers, and lightning arresters. equipment, which constitutes a medium-sized power distribution device outside the house. The main advantage of this design scheme is that the equipment cost is low. The disadvantage is that there are many equipments, the overall layout is complicated and messy, the floor area ...

AI Technical Summary

Problems solved by technology

The main advantage of this design scheme is that the equipment cost is low. The disadvantage is that there are a large number of equipment, the overall layout is complex and messy, the floor area is large, and the workload of operation and maintenance is large.

The outstanding advantages of GIS are high reliability, clear layout, saving land, small maintenance workload, strong environmental adaptability, etc., but relatively expensive

At present, GIS is widely used in power grid construction, but GIS design is not applied to the low-voltage side of 500kv substation. The reason is that the main circuit breaker cannot meet the needs of GIS. Not only makes it inconvenient for workers to overhaul, but also causes the differential range of the main transformer to be too small. Once a 66kv fault occurs, the time to remove the fault will be delayed, the differential protection will not operate, and only the backup protection will be activated.

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