EVALUATION AND TESTING OF INSULATION OF LARGE HYDRO GENERATORS

Abstract

Performance of large hydrogenerators mainly depend on the condition of its insulation system. Insulation deteriorates with ageing whether in service or without service. In this theis an attempt is made to review the procedure formonitoring the insulation condition and analy-sing the different standards followed in home and foreign countries. Experience has shown that the service life of hydrogenerators is strongly, effected by partial discharges in insulation system and thepartial discharge phenomenon has been analytically analysed in response to the literatures available. From the failure analysis data of 9 no. of hydro-generators (4 nos. from home and 5 nos. from foreign countries) a comparison has been drawn between thermoplastic and thermo-setting insulation systems and basing on the comparison a procedure has been selected for selecting the insulating materials....