Maximum force/ampere control of linear induction motor drives in field weakening region

Linear induction motor (LIM) drives have been investigated vastly for the past several decades. Attractive features, such as simple structure and easy maintenance, have made this family of machines utilized broadly in military, transportation, and aerospace, to name a few. Vector control is a dominant control strategy for LIM based on the assumption that this family of machines portray inherent similarities with their rotary counterparts. However, due to existence of end effects and magnetic asymmetry effects, vector control can not provide its expected functionality for LIM. In addition, end effects are more significant in high speed range including field weakening range. However, field weakening operation of LIM is still challenging in the relevant applications. Recently, a high grade control scheme, maximum force/ampere control, has been introduced. Compared with vector control, maximum force/ampere control has better transient performance, and steady state speed regulation. In this paper, operation of maximum force/ampere control is expanded to the entire speed range. Both simulation study and experiment results are provided for verification of control performance.