Power transformers are one of the most expensive and critical assets of the power sector. In this blog, we will discuss [1] principles of winding resistance measurement, a common transformer test prescribed in various standards such as IEEE C57.12.90-2006 Clause 5, IEC 60076-1 Clause 10.2, IS 2026-1 Clause 10.2; [2] OLTC condition analysis; and [3] …