Analysis And Research On The Interruption Performance Of 550kV SF6 Circuit Breaker

In this paper, associated with the key problem of 550kV SF6 high voltage circuit breaker which is used in GIS of three Gorges project, the mathematical models of static electrical field and one-dimensioned and two-dimensioned gas flow field during the overall breaking process in arc chamber of circuit breaker are developed. On the basis of gas discharge theory, the criteria to judge the interruption success is determined. Through the combination of one-dimensioned and two-dimensioned gas flow field software, the problem that the primary two-dimensioned gas flow field software can't calculate the hot gas flow field has been effectively solved. So it is very practical in engineering.Associated tightly with the stokes measured in small capacity current breaking and short-circuit breaking test duty T100a (short arc, middle arc and long arc), the electric field distributions 3 ms after current zero have been calculated. The cold gas flow field corresponding with small capacity current breaking is calculated. Based on the results derived from one-dimensioned gas flow field simulation, the two-dimensioned gas flow fields corresponding with short-circuit breaking test duty T100a (short arc and middle arc) are calculated as well. The author applies the electric and fluid theory to analysis the results in detail and evaluates the interruption performance of the circuit breaker. Furthermore, the calculated results are compared with the test results.The studied circuit breaker in this paper is very advanced in the electric domain nowadays, the software used are very credit and all the data used is got from real tests, so the calculated results will guide the direction of new product design in the future.