Abstract: To ensure a fair market competition mechanism and avoid aluminum winding transformers from impersonating copper winding transformers, which affects the safety and stability of power system operation, it is important to identify transformer winding materials. To avoid transformer structure damage and identify winding material accurately and effectively, this paper proposes a non-destructive identification method of transformer copper and aluminum winding material based on multiple temperature points, which identifies the winding material based on the resistance coefficient method combining with the results of multiple test points. The experiment results on a copper winding transformer and an aluminum winding transformer show that the proposed method is accurate and effective, and can be further extended to large-scale engineering practice.

Key words: transformer, winding material identification, resistance temperature coefficient, multiple points temperature