A new technical article has been published about transformer testing in Transformers Magazine, titled “Acceleration of LV winding resistance measurement”.
The winding resistance measurement requires extended time. According to IEC 60076-1 and IEEE C57.12.90 standards, the test should be performed using DC test current on all phases of the high voltage, low voltage, and tertiary sides, and for all tap positions. Speeding up this measurement is very attractive. This paper presents two approaches to transformer saturation: increasing the test current, and a special connection of the windings to increase the number of turns. The presented case study shows the difference between the regular test procedure and a modified one.
The paper is available on the following link.