Study on the forming mechanism and safeguard procedures of Electrical Fast Transient Burst

Electrical Fast Transient Burst(EFT/B) has characteristics such as short rise time and duration, high amplitude and repeat frequency. It can interfere the microcomputer protection system in the transformer station. This is a difficult problem and is hard to conquer. Based on the Mechanism of EFT/B when the no-load transformer switching-off, build the extinguish and restrike model of the isolating switch voltaic arc and got the according voltage waves. Because most integrating circuit for resisting transient disturbance have no-effect level of the pulse train, the safeguard procedures are adopted such as metal-oxide varistor, the RC protection, phase-controlled switch to test the ability of resisting EFT/B in the primary loop. Based on the analysis, a comprehensive method of resisting EFT/B which overcomes the above drawback is proposed.