Improved MRAC Based Sensorless PMSM Drive With Enhanced Speed Control for LEV Application

This paper introduces a sensorless speed and position control for a permanent magnet synchronous motor (PMSM) drive designed for light electric vehicles (LEVs). This approach utilizes a model reference adaptive control (MRAC) strategy, featuring novel flux and torque error based MRAC with an enhanced voltage model. Notably, this method does not rely on speed error and eliminates need for derivative terms in estimation process. Presented sensorless estimation method reduces effect of load variation in estimation as well as improves response from low to high speed. Moreover, to enhance speed controller working, an adaptive improved sliding mode controller (ISMC) is adopted, which adapts changes in terms of finite time convergence as well as accurate tracking and reduced chattering. To achieve fast convergence in finite time, fast integral terminal sliding surface along with novel reaching law is selected for sliding mode controller design. Furthermore, a simple predictive current controller is utilized, which eliminates need of a modulator and incorporates inverter nonlinearities. Simulation implementation of control is executed in Simulink and its experimental performance is verified on a laboratory test setup. A comparative analysis of PI controller with improved SMC and sensorless position estimation by improved flux MRAC with conventional MRAC is done.