Simple and Accurate time-domain method for internal fault location in layer-type transformer windings

Internal winding faults are among the most common causes of transformer failure. Once a fault occurs, a fast and efficient method for its detection and location is required to repair and reconnect the device, thus avoiding further delays in the network operation. This paper introduces a simple method for the location of internal winding faults. This method is based on time-domain terminal measurements of wave propagation along the winding. By means of low-cost laboratory components (a lowvoltage DC source and an oscilloscope), different types of faults in layer-type windings can be detected and located with high accuracy. A frequency-domain distributed-parameter winding model is used to predict the transient response of the winding subjected to different types of faults. FEM simulations are used to compute the model parameters. A test case is presented to demonstrate the efficacy of the fault location method.