Research On Vibration Characteristics And Online Monitoring Methods Of Steam Turbine Generator Under Internal Faults

This paper focuses on the interturn short-circuit fault in generator stator rotor windings. It provides an analysis of the static characteristics and the unbalanced electromagnetic force characteristics of rotor in normal conditions, It provides an analysis of the static characteristics and the unbalanced electromagnetic force characteristics of rotor in normal condition and rotor intern short-circuit conditions respectively. This paper also shows the mechanical and vibration characteristics of stator end windings. The main findings are as follows.(1)Based on the specific parameters of the experimental motor, generator finite element analysis model is established. This paper provides a precise caculation of the unbalanced electromagnetic force of rotor in short-ciruit condition, and a comparison of the equivalent magnetic flux method and the magnetic potential superposition method. And in this paper, the speed characteristic in actual units is tested, and the mechanism of the common accidents is analyzed.(2) This paper provides an analysis of the magnetic field distribution of the generator end windings under various kinds of internal fault condition, and a description of the change of current and voltage in the end bars under fault conditions. And it also demonstrates the Lorentz force and unbalanced magentic force of the end windings, and hence researches the vibration of end windings under the action of the alternating radial force and tangential force and axial force.(3) Based on the findings, the end winding vibration fault analysis and detection system system is established and applied in the unit operation, which proved satisfactory and beneficial for online fault monitoring.