An on-load tap changer (OLTC) is on

An on-load tap changer (OLTC) is one of the mosterror-prone parts in the transformer. The stability of the entirepower system will be greatly threatened if the OLTC fails. It isnecessary to diagnose the mechanical fault of OLTCs. At thesame time, the mechanical fault signals are not easy to collectduring practical application. It is desirable to have indicatorsthat help to access the condition of the OLTC with a smallnumber of fault samples. This paper describes a strategy fordistinguishing different mechanical diagnostics of OLTCs basedon dynamic time warping. By synchronization, framing, andFourier transform, the signal can be represented by an energymatrix, which can be used to distinguish different conditions ofthe OLTCs and shows the severities of the fault. Some simulatedexperiments are designed and in order to make the simulationsclose to reality, all experiments are taken in a tank which isfilled with transformer oil. These experiments demonstrate thatthe proposed approach can effectively diagnose different OLTCfaults under different fault severities.