Noninvasive Condition Assessment and Event Timing For Power Circuit Breakers

Noninvasive diagnostics, involving short-time spectra, short-time energy, and automatic timing techniques, have been applied to assess the mechanical condition of oil and puffer circuit breakers and to determine the timing of events occurring during operation. Analysis of the vibration signatures leads to (1) the characterization of a circuit breaker through a single index, the Resolution Ratio (RR) and (2) the automatic timing algorithms. The accuracy of the automatic timing algorithms permits both the timing of events and the detection of shifts in the timing associated with changes in the condition of a unit.