Research On Arc Characteristics Of Hybrid Circuit Breaker

The capacity of power system increases constantly, which presents high requirements to the breaking capacity of high voltage circuit breakers. SF6gas circuit breaker and vacuum circuit breaker are widely applied high voltage switches. SF6circuit breaker acts as the leading product above110kV high voltage field, its breaking capacity is affected by the rise of the recovery voltage.At the same time the SF6gas has also been advised to restrict for use due to its greenhouse effect. However, the voltage withstand level of vacuum circuit breaker is limited by its long length of vacuum gap, which restricts its development at a higher voltage level.To take advantage of the short gap arc quenching performance of vacuum interrupter and the strong insulation characteristics of SF6interrupter simultaneously, we provide a kind of hybrid circuit breaker comprised of the two in series. This can not only overcome the shortcomings of the two interrupters, but also play both advantages. And thus a new type of large capacity environmental and economic circuit breaker has been developed.On the basis of discussion on power system and the circuit breaker’s development, the purpose and significance of the hybrid circuit breaker design are proposed in this paper. The dielectric insulation and recovery characteristics of the hybrid circuit breaker are analyzed in theory, and theoretical model of the hybrid circuit breaker arc has been deduced based on the medium characteristics and theoretical models of vacuum and SF6are introduced. The simulation model of hybrid circuit breaker has been set up using the electromagnetic transient simulation software EMTP-ATP. At the same time, short circuit test of the hybrid circuit breaker on40.5kV voltage level has been simulated by changing the simulation parameters. The breaking results of different circuit conditions and model simulation parameters have been compared. The interaction between the two fractures in the hybrid circuit breaker during short-circuit current interruption is studied. Also by using the method of experiment, the insulation and breaking characteristics of the hybrid circuit breaker have been verified. Meanwhile, the parameters of the equations for the arc models have been modified by MATLAB software.In this paper, breaking mechanism of the hybrid circuit breaker has been analyzed and verified from three aspects:theory, simulation and experiment. Results have shown that the hybrid circuit breaker is feasibility. And the interaction relationship between vacuum and SF6fractures in the hybrid circuit breaker is verified. It turned out that vacuum fracture can help SF6fracture’s breaking capacity increasing, thus reducing use of SF6gas. And to a certain extent, the economization and low carbonization of high voltage circuit breakers’design is realized.