Understanding the Value of Electrical Testing for Power Transformers

Understanding the Value of Electrical Testing for Power Transformers

The electric power industry is always looking for the best approach to better determine and continually track the condition of power transformers. It is important to understand the need for and value of comprehensive testing of power transformers.

Through careful selection, hierarchal value, and appropriate times of use, today transformer diagnostics generally consists of a comprehensive suite of basic or standard electrical field tests including:

  • Power Factor
  • Exciting Current
  • Turns/Voltage Ratio
  • Leakage Reactance
  • DC Winding Resistance
  • Sweep Frequency Response Analysis (SFRA)

These specific diagnostic tests have been selected as the primary focus for this presentation and discussion. This paper focuses on how diagnostic techniques can be applied to power transformers as part of the standard condition assessment protocol. The audience will be provided with an understanding, application, and analysis of these tests, supported by specially selected case studies validating the value that these diagnostic tests bring to testing, and finally assessing, power transformers.