118 / 2018-12-10 20:34:04

Study on low temperature characteristics of oil-immersed inverted current transformer

current transformer, low temperature characteristic, frequency domain dielectric response, partial discharge, power frequency loss

The oil-immersed inverted current transformer is widely used in the power grid because of its outstanding advantages. In order to explore the low-temperature dielectric properties of the main insulation of oil-immersed inverted current transformer. In this paper, the oil-immersed inverted current transformer is tested by frequency domain dielectric spectrum, partial discharge, power frequency loss factor and power capacity under low temperature. Test results show that the frequency domain dielectric spectrum of oil-immersed inverted current transformer at different temperatures has a trend of first decline and then an upward trend. When the temperature below -40°C, the frequency domain dielectric spectrum curves differ very little and almost coincide in the low frequency range. The partial discharge signals are generated when the temperature below -45°C. The power frequency loss factor of oil-immersed inverted current transformer increases with the decrease of test temperature, the rate of change varies from slow to fast. The capacitance decreases with the decrease of test temperature. For test results, from the viewpoint of dielectric physics analyses, the variation law of frequency domain dielectric spectrum, partial discharge, power frequency loss factor and power capacity with temperature at low temperature were obtained. The test results in this paper have some reference value for the study characteristics of oil-paper insulated power equipment at low temperature.