SFRA test method application for turbo generator rotor winding

Abstract

The development of technology in the present makes the testing method for analysis to know the defect to insulation winding in rotating machines is varied. There are many specific testing tools to determine the damage. The authors of this paper conduct a preliminary study using sweep frequency response analysis (SFRA) to detect and find damage in the turbo generator rotor winding. SFRA is a test equipment performed on transformers based on the working principle of RLC which are Resistive, Inductive, and Capacitive. The importance of the damage identification process is needed to maintain reliable rotor generator and avoid catastrophic defect to equipment and losses to power plant. In one case study, the rotor generator experienced high vibration indication when operating in high reactive power and the SFRA test results on the rotor winding shows a mismatch between two curves. In another case, a mismatch of SFRA result showed winding deformation, such as coil elongation, without high vibration indication in rotor generator. After inspection, repair, measurement and testing, the SFRA method proves that it can show indications of defect without major dismantling.