The decision of position of a partial discharge in power transformer by measurement of ultra sonic signal

초음파 신호측정에 의한 변압기내의 부분방전위치측정

Detecting acoustic emission (AE) provides an appropriate method to diagonize on-line transformers, since acoustic signal is not influenced by strong electric field. Then AE versus AE signal processing method is investigated. But this processing is difficult that decision of starting point of AE wave with acoustic noise. This problem is sloved by correlation which calculate time interval between two signals eactly. This paper presents a technique locating the eact position of the partial discharge (PD) in a power transformer by the correlation of the AE signals from two ultrasonic sensors. And PD position is displayed on monitor. Laboratory tests confirmed that the proposed method can be used for locating the PD in power transformer.