On‐line identification of power transformer short‐circuit parameters based on instantaneous phasor

Abstract

Abstract Among the various faults of power transformers, winding faults are particularly common. It is known that short‐circuit parameters can reflect the winding condition, so the on‐line identification of short‐circuit parameters is of great significance for monitoring the power transformer health. An instantaneous phasor extraction method based on Second‐Order Generalised Integrator Frequency‐Locked Loop is introduced, and then an on‐line identification algorithm of power transformer short‐circuit parameters based on an instantaneous phasor is proposed. In this algorithm, multi second‐order generalised integrator frequency‐locked loop is used to extract the fundamental instantaneous phasors of the voltage and current signals on the primary and secondary sides of the transformer. After that, the short‐circuit parameters are calculated from the phasor equation of the transformer. The effectiveness of the proposed algorithm has been verified with experimental results.

Keywords

• instantaneous phasor
• on‐line identification
• power transformer
• second‐order generalised integrator frequency‐locked loop
• short‐circuit parameters