Status and progress in study of dielectric response technology for oil-paper insulation

Oil-paper insulation is widely used in power equipment such as power transformer, high voltage bushing, power cables. Currently, major defects and/or failures are caused by insulating materials' ageing and/or degradation, thus, the reasonable and effective insulation condition detection and assessment are of significance in guaranteeing reliable operation and prolonging the usage life of power equipment. Dielectric response technology, with the advantages of accurate and reliable results, has been widely used for condition assessment of oil-immersed equipment in recent years. On the basis of extensive analyses of dielectric response study and application, we introduced three kinds of dielectric response methods, including RVM, PDC, and FDS, and relevant theories, as well as the theoretic explanation models for oil-paper insulation dielectric response function. Combined with multi-type oil-immersed equipment's situations on-site, the progress of dielectric response measurement and influencing factors are emphatically discussed, the existing problems are analyzed, and related suggestions are put forward. Finally, the future direction of condition detection and assessment based on dielectric response technology are also presented.