ABSTRACT:

Ageing of non-ceramic insulation can conduct into failures of the power system, where usually pollution plays an important role in the degradation process. These failures cannot be evaluated by applying IEC 61109 ageing tests, because such tests are considered as screening tests and up to now these tests are quite questionable. Therefore research of new test methods and diagnostic tools are needed to predict long-term performance of non-ceramic insulators. A non-standard method for insulation ageing is modified and used in this work to evaluate non-ceramic components of breakers, bushings and surge arresters. Different diagnostic tests are proposed to analyse the evolution in the degradation process of these apparatus. The results showed that the applied methodology and the proposed tests may evaluate in a more realistic way the performance of new non-ceramic insulating material used in electrical equipment.