Advanced On-line Condition Monitoring of, and Inter-turn Short Circuit Detection in, Power Transformers

Abstract

Transformers are an important part of any electrical power system network, warning of fault before failure is vital. The application of on-line fault detection reduces the cost of outages and the possibility of unpredicted failures. This paper outlines an electrically based on-line condition monitoring and short circuit detection method for power transformers. This method uses measurements of voltage and current in both sides of a transformer to classify its health and to identify fault conditions while in operation. Simulation results, relating to a number of short circuit winding faults, are analyzed and discussed. The results confirm that it is possible to identify a variety of short circuit conditions in primary and secondary windings from externally measurable parameters, i.e. measurement of voltages and currents in a transformer’s windings can, based on available winding data, identify changes inside the transformer. The effect of load variation on the magnitude of the measured voltages and currents is also considered in this analysis.