Experimental Test Bench for Power Transformer Differential Protection Testing Methods Evaluation

This paper presents an experimental test bench for generating disturbances in a transformer to validate power transformer differential protection methods. The experimental setup uses a 1 kVA three-phase transformer with accessible taps in its windings to generate challenging inter-turn faults. Moreover, external faults and transformer energizations with and without a permanent fault were also generated in this experiment. This paper evaluates the performance of traditional phasor-based and wavelet-based differential protection methods with representative transformer events obtained in the laboratory. Both methods performed well. However, the wavelet-based method was the fastest, even considering a high level of noise. The coherent results highlight the feasibility of using the experimental setup as a valuable step for validating differential protection methods based on the ampere-turn balance.