218 / 2024-04-25 22:41:49

Technical Challenges for Vacuum Interruption at Very High Voltages

VHV Vacuum,Vacuum Interrupters,VCB

The present trend is for Vacuum Circuit Breakers to move into ever higher voltage classes as a replacement for SF6 circuit breakers. However, as the system voltage class increases above 145kV it becomes increasingly more difficult for a vacuum interrupter to meet the circuit breaker requirements. The paper discusses the technical reasons for this which are driven by the very different physics of the vacuum arc and insulation compared to those of Gas Circuit Breakers. The different limitations are discussed together with their mitigations, and it is suggested that there is a voltage limit beyond which a single break Vacuum Interrupter is not viable.