Analysis of the Increase in Generator Rotor Vibration after a Short Circuit in the Generator

The vibration of the generator has an important impact on the stable operation of the equipment and is directly related to the safe production of electrical power. There are many reasons for analyzing the factors affecting the vibration. Design, manufacturing, and installation may all cause the vibration of the generator. In this study, the factors affecting the vibration of generator rotor after short circuit is analyzed. The 210 MW steam turbine generator set of a private operator plant was produced by a private Group using the latest technology. The turbine generator is a six-mass structure connected by a steel shaft. The generator is waterhydrogen- hydrogen cooling. On January 26, 2018, the plant's No. 3 unit was connected to the grid for the first time. When the load reached 185 MW, the generator had a short circuit accident. After the short circuit, the different parameters and vibrations are measured and compared by different tests. The vibrations after the short circuit are also tested for different conditions, the rotor and stator winding resistances are checked after rewinding. Finally the found that the electrical, thermal, and mechanical stresses of the generator's three-phase short circuit adversely affect the rotor's balance.