A novel switching scheme for direct thrust control of LIM with reduction of thrust ripple

The linear induction motor (LIM) drives using conventional direct thrust control (DTC) schemes have drawbacks of large thrust ripples in low speed range and so on. In this paper, the thrust ripples of the DTC-based LEVI drives are theoretically analyzed. A novel switching scheme using synthesized voltage vector and magnitude modulation method is proposed to replace the conventional switching table in DTC. The experimental results show that the proposed scheme is capable to reduce the thrust ripples of DTC effectively.