Guide for Determination of Maximum Winding Temperature Rise in Liquid-Filled Transformers
|Publication Date:||21 June 2000|
This guide provides guidance for developing mathematical models and test programs to determine the steady state maximum (hottest-spot) and average winding temperature rise over ambient for all liquid-immersed distribution, power, network, and regulating transformers manufactured in accordance with IEEE Std C57.12.00-2000.1
IEEE Std C57.12.00-2000, subclause 22.214.171.124, states, "the maximum (hottest-spot) winding temperature rise above ambient temperature shall be determined by either
a) Direct measurement during a thermal test in accordance with IEEE Std C57.12.90-1999. A sufficient number of direct reading sensors should be used at expected locations of the maximum temperature rise as indicated by prior testing or loss and heat transfer calculations.
b) Direct measurement on an exact duplicate transformer design per a).
c) Calculations of the temperatures throughout each active winding and all leads. The calculation method shall be based on fundamental loss and heat transfer principles and substantiated by tests on production or prototype transformers or windings."
This guide describes recommendations for a manufacturer's test program or mathematical model to demonstrate compliance with the above requirements.
1Information on references can be found in Clause 2.