Sliding‐mode observer based sensorless vector control of LFSPM motor for long‐distance drive system

Abstract

A new series of linear flux-switching permanent magnet (LFSPM) motors has elicited considerable attention. This series incorporates the merits of the high efficiency of permanent magnet linear motors and the low cost of linear switched reluctance motors for a long-distance drive system. However, the vector control of the LFSPM motor requires an expensive and unreliable linear encoder, which must be as long as the entire railway (or at least the whole linear motor). Such a large encoder will lead to extra costs and will even weaken the benefit of the motor performance. Thus, developing its sensorless control for engineering applications is necessary. Sliding-mode sensorless control has the advantage of strong robustness to parameter variations and external disturbances, as well as high dynamic performance, which is important for long-distance drive systems. The proposed algorithms can extend the minimum operating speed, thereby enabling the motor to work at a lower speed. Both simulation and experimental results are provided for verification.