ASSESSMENT OF THE ELECTRIC HYDROGENERATOR STATOR INSULATION CONDITION BY MEANS OF ON-LINE PARTIAL DISCHARGE MEASUREMENT

摘要

The paper presents the principle of the measurement method, the quantities characterizing the partial discharges and the criteria utilized for the evaluation of the insulation condition. Further, the results of the measurements of several hydro generators and the variation with time of the quantities that characterize the partial discharges, Q_(max) magnitude and the normalized quantity NQN, over a period of about 10 years are presented. A synthetic presentation of the conclusions of the insulation condition annual evaluation and of the decisions that have been taken relating to the hydro generator maintenance has been made. The paper ends with several considerations on the method and evaluation criteria efficiency.