AN UPDATE ON TEST EXPERIENCES WITH SHORT-CIRCUIT WITHSTAND CAPABILITY OF LARGE POWER TRANSFORMERS

摘要

Experience is reported of short-circuit testing of large power transformers during the past 9 years by KEMA in the Netherlands. In total, 62 transformers > 25 MVA participated in the survey. KEMA shows that at initial access to standard IEC short-circuit tests, 30% failed initially in case of a wide range of power (62 transformers 25 - 440 MVA tested). During the past 5 years, almost all of the initial failures were observed at the upper end of both voltage and power.