Flux-Weakening Control of Linear Induction Motor Drives Considering the Primary Resistance and End Effect

Abstract

Indirect field-oriented control (IFOC) of a linear induction motor (LIM) drive is an important challenge because of the end effect and nonlinear behavior of the LIM drive. It becomes more complex in high-speed applications and flux-weakening (FW) regions when current and voltage constraints must be satisfied. Moreover, considering the primary resistance in voltage constraint inequality makes the calculations even more complicated.This work presents a new FW control algorithm for LIM drives, considering the end effect and the primary resistance. Consequently, the reference d-axis current and maximum q-axis current are modified considering the primary resistance and end effect. Accordingly, new control strategies for the partial and full FW regions are implemented in a LIM drive. Fuzzy logic controller (FLC) has been used to overcome the nonlinear behavior of LIM drive and achieve appropriate dynamic characteristics. Simulation results validate the effectiveness of the suggested LIM drive based on FLC in different speed regions. Moreover, results manifest that in a LIM drive with end effect consideration, the base and the critical speeds are not constant. As the LIM speed increases, the base frequency reduces, whereas the critical frequency increases.