Small-Signal Modeling and Decoupling Control of a Doubly-Fed Linear Motor for Maglev Application

For maglev applications driven by linear motors, the contactless power supply for the mover side is a significant challenge. The doubly-fed linear motor (DFLM), with its slip frequency as an additional control variable, provides potential to realize contactless power supply on the maglev. On the DFLM, decoupling control of three functions: traction, contactless power transfer, and levitation, is realized in this article. Specifically, a small-signal model of DFLM is established as the basis for the decoupling control design. The model reflects the coupling among the three functions. Finally, the effectiveness of the proposed control design is validated through experimental studies.