Research On Technical Reform Of 220kV Circuit Breaker

High-voltage circuit breaker which needs to execute breaking-closing operation accurately according to the instructions is the main equipment performing control and protection functions in power transmission and transformation system.The reliability of operation of high voltage circuit breaker is of the utmost importance.Refusal departing,refusal closing and malfunction of circuit breaker will lead to a great loss of power system.Operating mechanism is an important part of the circuit breaker,which provides fast-and-off electronic circuit of circuit breaker with energy.Operating mechanism realizes fast-and-off operation in accordance with definite order of operations,and keeps in the corresponding fast-and-off positions.The thesis combines with the 220 kV circuit breaker technological upgrading project of 220 kV Xuepo Substation in Xuchang area.The running conditions and common problems of LW6B-252 circuit breaker designed by Henan Pinggao Electric Co.Ltd running in the substation is discussed firstly.LW6B-252 circuit breaker equipped with hydraulic operating mechanism of which the general trouble and blemish of frequent bulge and oil leakage occurs frequently because of complex structure,high machining accuracy and delayed maintenance in recent years,affects the performance of normal fast-and-off of circuit breaker and stable operation of power grid.3AP1-FG 252 kV circuit breaker produced by Siemens(Hangzhou)high-voltage switch limited company takes the place of the original LW6B-252 circuit breaker.There is a high advancement on the 3AP1-FG 252 kV circuit breaker taking single break and spring mechanism in current equipments.Oil-free and high reliability of operating mechanism meet the running requirement.Work load of routine maintenance is highly reduced to improve safety and stability of devices and power grid.Thirdly,It is started with field maintenance and field observation of the used circuit breaker.Replacing working of circuit breaker is expatiated further by making power failure schemes,formulating standard operation instructions,operation procedures,field safety control,construction installation and handing over acceptance experiment.Field actual operation and operation procedures are refined to enable the workers to finish the technological upgrading work successfully.At last,there is a contrast between the running conditions and different operating mechanism of circuit breaker replaced before and after.By the contrast,the defects of circuit breaker after technical innovation reduce significantly,and the amount of maintenance in routine is reduced by 80%.The result shows that these methods are valuable both in theory and in practice.