A practical scheme for vibration signal measurement-based power transformer on-load tap changer condition monitoring

Vibration signal measurement has been adopted for online condition monitoring of power transformer's On-Load Tap Changer (OLTC). By comparing measured vibration signals collected at different stages of an OLTC, it could be possible to identify mechanical condition changes of the OLTC. However, it is a rather difficult task to interpret the vibration signal measured from a field OLTC and subsequently make assessment of its condition. This paper presents a practical scheme for vibration signal measurement-based OLTC condition monitoring. It consists of a vibration signal interpretation algorithm and a waveform-based vibration signal comparison method. Case studies of vibration signal measurements of OLTCs are presented to verify the methods presented in this paper. Finally, a framework for OLTC mechanical and dielectric condition monitoring and diagnosis is presented