797 / 2022-03-31 22:50:00

Influence of low temperature on dielectric properties of current transformer

power frequency loss factor; dielectric characteristics,current transformer; low temperature;

The oil-immersed inverter-type current transformer is widely used in power grid because of its advantages． In order to explore the low temperature dielectric properties of the main insulation of the oil-immersed inverter-type current transformer， frequency domain dielectric spectroscopy， power frequency loss factor and capacitance of 66 kV and 110kV oil-immersed inverter-type current transformer were tested at low temperature in this paper．The results show that at different temperatures the frequency domain dielectric spectrum of the oil-immersed inverter-type current transformer first descends and then rises． When the temperature was below － 40℃ ， the difference of the frequency domain dielectric spectrum of the current transformer is very small and almost coincides at low frequency． The power frequency loss factor of oil-immersed inverter-type current transformer increases with the decrease of the test temperature， and the change rate is slow to fast， while the capacitance decreases at a constant speed with the decrease of temperature．