75 / 2017-02-28 15:54:15

Aging Characteristic Parameters Analysis of Transformer Oil-paper Insulation Based on Time Domain Dielectric Method

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In order to extract characteristics of oil-paper insulation aging state and apply the time domain dielectric method to the nondestructive measurement of oil-paper insulation aging state better. This paper performed polarization and depolarization current (PDC) on oil-paper insulation sample with different aging state under laboratory conditions. Then obtained the equivalent model parameters and put forward system pole as characteristic parameter of oil-paper insulation aging state to established relationship between them. Finally verified feasibility of system poles used as oil-paper insulation aging characteristic. The results showed that: parameters of extended Debye model are very sensitive to oil-paper insulation aging state and time constant in branches whose time constant is greater than 1 000s increases with the aging time increasing; There is exponential function relation between polymerization degree and system poles came from branches whose time constant is greater than 1 000s. Poles with smaller value has the higher fitting goodness. The optimized relative system poles fitting better with degree of polymerization and isn’t affected by the transformer geometric dimensions. The test verifies the feasibility that system poles could be used as characteristic of oil-paper insulation aging state.