ACOUSTIC TAP-CHANGER MONITORING USING WAVELET ANALYSES

The acoustic signature as a diagnostic tool is a proven tool in many industrial applications. In the field of electrical equipment the On-Load Tap-Changer (OLTC) is the only mechanical part of a high voltage transformer which is responsible for voltage control that means the switching of regulating windings. The fundamental principle of an OLTC operation is the mechanical switching of contacts in vacuum or oil. In the process of OLTC operation the acoustic noise and the vibration reflect mechanical or electrical events during the switching process. The information concerning the OLTC operation can be extracted from the vibro-acoustic measurements. This contribution introduces a novel method for analysis, visualization and interpretation of the vibro-acoustic measurements on OLTCs. The…