Diagnosis Methods Based on Tests, Recordings and Numerical Processings of Operating Regimes of Synchronous Generators from Large Electro-Energetic Groups

This paper presents the conclusions deduced from the recording, analysis and numerical processing of operational data from an electro-energetic group of 330 MW. There are presented numerical results from various operating regimes: inductive, resistive and capacitive, corresponding to an active power delivered toward the power system of almost 210 MW. The analysis focuses on electric quantities from the main and auxiliary generators, before and after the fully-controlled rectifier. Numerical processings revealed a reversed active power flow (from the main generator toward the auxiliary generator) carried by high-order harmonics. The presence of some non-typical harmonics within the voltages and currents waveforms (especially in the auxiliary generator) proves its non-symmetrical operation, caused by the asynchronous control of the thyristors from the fully controlled rectifier that are connected in parallel along the same phase