DC Current Control Method of a Current Superimposition Variable Flux Machine

Abstract

We have proposed a current superimposition variable flux machine for traction motors. The torque-speed characteristics of this machine can be controlled by increasing or decreasing the DC current which is superimposed on the AC current. However, because of noises and the change of coil resistances, the DC current was difficult to apply constantly. In this paper, we propose a DC current control method and verify the effectiveness by carrying out measurements on a prototype. First, the structure and control method are described. Next, the effectiveness of the proposed method is verified by using FEA. Finally, the N-T characteristics are measured on a prototype.