Study On The Aging Characteristics Of Turn-to-turn Insulation Material Of Dry-type Air-core Reactor

Dry-type air-core reactor has been widely used for strengthening the stability of the power system and improving the quality of energy transmission,so the safe operation of the reactor is essential to the power system.The damage of the reactor is mainly caused by the turn-to-turn insulation failure.Therefore,it is significant to improve the product quality of the dry-type air-core reactor and reduce the failure rate of the turn-to-turn insulation during the operation that we study on the aging characteristics of turn-to-turn insulation material of dry-type air core reactor.With reference to the manufacturing process of dry-type air-core reactor designed to produce the reactor turn-to-turn insulation structure model,and then manufactured the test electrodes according to the model specifications.The frequency of electrical aging and breakdown test platform,the over-voltage cumulative effect test platform and the thermal aging test platform were established.Carried out a constant electrical stress aging and step electrical stress aging test,and analyzed statistically the electrical aging test data under two kinds of stress.The over-voltage accumulation test was carried out,during which the initial partial discharge voltage and the residual insulation resistance data were obtained after each aging cycle.After the completion of the design cycle,the model was subjected to frequency breakdown test to obtain the breakdown voltage data.A number of thermal aging cycles were designed to perform a single thermal aging test corresponding to different operating years.The initial partial discharge voltage and residual insulation resistance of the model were measured before aging and at the end of each aging cycle.After the completion of the design cycle,the breakdown voltage data of the model is obtained under the power frequency,the direct current and the exponential decay wave.The over-voltage accumulation test of the model after thermal aging was carried out to obtain the applied voltage and breakdown time data.The experimental results are shown below.The life index n obtained by the step electrical stress aging test can not be extrapolated to the dry-type air-core reactorworking life well.The initial partial discharge voltage and the residual insulation resistance are highly correlated with the degree of the turn-to-turn insulation damage.Over-voltage accumulation has a great influence on the inter-turn insulation of the reactor.Single thermal aging has little effect on the inter-turn insulation of the reactor.The ability to withstand over-voltage drop after thermal aging.