Current Communication in High Voltage Switchgear Contacts Under High Currents

摘要

Circuit breakers have to interrupt higher and higher currents (more than 63kA) and must be designed to operate reliably at an acceptable cost. One aspect of circuit breaker design improvement is related to the commutation of current from main contact system to arcing contact system. The contact erosion induces the modification of the contact geometry and generates particles that can be very harmful for the breaker's dielectric withstand. This article presents results on the influence of different types of contact materials on parameters like commutation time and energy, arc voltage, particle generation and erosion contacts. The benefit of the use of refractory materials on the listed parameters is discussed. On the basis of these results improvements of design criteria for circuit breakers are presented.