Shielding Design for Current Sensor of Excitation System Based on 3-D FEM

In an excitation system of a certain type synchronous motor, current sensor for detection and protection often works under abnormal conditions. It leads to inability to play the role of the normal current detection, or even false tripping down the serious accidents. This failure is mainly generated by electromagnetic interference. Finite element analysis software is used to build the main circuit 3-D model of excitation system, by analyzing electromagnetic interference (EMI). Major source of interference is located. A method of installation shielding sleeve is designed, through theoretical calculations shield manufacturing materials are determined, and the effectiveness of this shielding design is clarified based on the existing finite element model. Through experiments the correctness based on the finite element method of such analysis is correct is verified.