Study on the influence of testing temperature on time-domain dielectric characteristics of oil-paper insulation

In order to better apply time-domain dielectric response technique in non-destructive diagnosis of transformer's aging state, the influences of testing temperature on time-domain dielectric property of oil-paper insulation was investigated. Firstly, the experiments of oil-paper insulation winding model under different testing temperatures were carried out. After then, the integration of time-domain dielectric measurement technique was implemented by extended Debye model and the influence of testing temperature on time-domain dielectric behavior and its characteristic parameters were intensively studied. Finally, a new method of structuring current standard master curve by using time and amplitude panning factor was proposed to eliminate the impact of testing temperature. It demonstrates that the time-domain dielectric property of oil-paper insulation and its characteristic parameters was significantly influenced by testing temperature. Testing temperature must be taken into account in the application of time-domain dielectric response to assess the condition of oil-paper insulation. Otherwise it would lead to the untrue assessment result. Using the current standard master curve could not only eliminate the impact of testing temperature but also acquire more time-domain dielectric information in reflecting the status of oil-paper insulation without additional test time.