Testing full-core and partial-core transformers at ambient and cryogenic temperatures
Single phase, full-core transformers were fitted with either silicon or amorphous steel cores and immersed in either standard transformer oil or liquid nitrogen. Each transformer was subjected to a capacitance and dissipation factor test to determine the integrity of the insulation systems. Open circuit and short circuit tests were then undertaken to determine core and winding losses. Similar tests were also conducted on a silicon steel partial-core transformer. Full load tests on this transformer showed a high level of efficiency and low regulation, even at ambient temperatures.