Measurement and analysis of in-plane eddy current in lamination steel using a new tester

In stator end regions of turbogenerators, the in-plane eddy current arises in the lamination steel. In this paper, a simple tester to measure the in-plane eddy current losses in lamination steel is newly designed and built. A measurement method to separate the in-plane losses from the total core losses in the tester is presented. The in-plane losses are measured and computed by finite element analysis. The computed losses agreed well with the measured ones. The accuracy of the analysis has been confirmed. The eddy-current phenomena in the tester are examined by the analysis. The computed results show that the in-plane eddy current has nearly resistance-limited characteristics. The eddy current generates the looped flux inside a steel sheet.