Evaluation Method Of Arc Extinguishing Performance Of 10kV Vacuum Circuit Breaker Based On Radiated Electromagnetic Waves

Vacuum circuit breakers are widely used in the field of power distribution,and their arc extinguishing performance directly affects the stable operation of the power grid,so effective evaluation of them is of great significance.Based on the previous use of radiated electromagnetic wave method to evaluate the arc extinguishing performance of SF6 circuit breakers,good results have been achieved.Based on this method,this paper studies the correlation characteristics between the arc extinguishing performance of 10kV vacuum circuit breakers and the radiated electromagnetic wave signal,and explores the 10kV vacuum Evaluation method of circuit breaker arc extinguishing performance.A damped oscillation high-voltage and high-current loop was built,and a lOkV vacuum circuit breaker simulation test platform was established to simulate the state of the vacuum interrupter and the high-voltage and high-current breaking conditions.The influence of four factors,vacuum degree,contact wear degree,breaking speed and breaking voltage on the electromagnetic wave signal of 10kV vacuum circuit breaker during the breaking process is studied.The radio frequency signal of radiated electromagnetic wave is collected and the fast fourier transform is performed on it to obtain the power spectrum.The generation or disappearance time point,the beginning and ending time,the amplitude and the generation frequency of the radiated electromagnetic wave detection signal under different working conditions are counted and analyzed.Finally,two characteristic quantities of the beginning and ending time and amplitude of the radiated electromagnetic wave detection signal are extracted.The research results show that when the vacuum degree decreases,the beginning and ending time of the radiation electromagnetic wave detection signal is prolonged and the amplitude decreases;when the contact is severely worn,the beginning and ending time of the radiation electromagnetic wave detection signal i s prolonged but the amplitude changes little;when the breaking speed decreases,it is at normal vacuum radiated electromagnetic wave detection signal has no obvious change rule under the conditions,but the beginning and end time of radiated electromagnetic wave detection signal is prolonged and the amplitude changes little under the condition of severe vacuum degree;when the breaking voltage is increased,the beginning and end time of radiated electromagnetic wave detection signal is prolonged under normal vacuum conditions However,the amplitude has no obvious change rule,and under the condition of severe vacuum decrease,the beginning and ending time of the radiated electromagnetic wave detection signal is prolonged and the amplitude does not change much.There is no significant change in the radio frequency signal of radiated electromagnetic waves under different working conditions.The signal amplitude is about 0.5V,the energy is concentrated between 300MHz and 400MHz,and there is a relatively high component between 1GHz and 1.2GHz.Based on the above research,it is shown that the radiated electromagnetic wave method can realize the live evaluation of the arc extinguishing performance of 10kV vacuum circuit breaker.