Investigation of Pressure Measurement in SF_6 Puffer Circuit Breaker in No-load and Heavy Current Interruption Conditions

The transient pressure in arcing chamber of 252 kV puffer circuit breaker is measured by piezoresistive pressure sensors and fibre optical pressure sensors under the conditions of no-load and 10 kA heavy current interruption. The transient pressure at four measuring positions, including the cylinder, the upstream and downstream sides of nozzle, and the nozzle throat, is obtained. The measurement method and system are introduced. The results show that both piezoresistive pressure sensor and fibre optical pressure sensor can be used to measure the transient pressure in arcing chamber effectively, and the effect of the length of pitot tubes on measurement cannot be neglected.