Acoustic diagnosis of high voltage circuit-breakers

A noninvasive technique for assessing the condition of circuit breakers by considering the acoustic signals generated during nonenergized switching is described. Mechanical malfunction, wear, and other types of abnormal behavior can be detected as changes in this acoustic signature. Digital signal processing techniques known from speech recognition were successfully applied to extract, compare, and present the information from the breaker signatures. A fault in the release mechanism which developed over time and eventually rendered one pole of a circuit-breaker inoperative was detected in an early stage, demonstrating the efficiency of this diagnostic technique