Continuous Fast Terminal Sliding Surface-Based Sensorless Speed Control of PMBLDCM Drive

Abstract

Variable frequency drives (VFDs) have been used for position sensors for many years. Alternatively, reliable VFDs for smart autonomous systems require the simultaneous configuration of sensors and sensorless operation. This paper details the design and implementation of a continuous fast terminal (CFT) sliding mode controller (SMC) based speed controller and speed estimation through the CFT sliding mode observer (SMO) that accounts for iron loss while calculating total disturbances. The rotor speed dynamics of the PM brushless DC motor (PMBLDCM) drive system is first investigated considering lumped disruption (interference, parametric complexity, and non-linear dynamics). The built-in SMC can control the rotor speed in real time, as well as analyze and compensate for aggregated interruptions in rotor speed dynamics. Additionally, the field-oriented control (FOC) method is developed to maximize torque production while drastically minimizing torque ripples. With this approach, the zero torque pulsation constraint is gradually achieved at a wide speed range. The validation of the proposed CFT-SMC with FOC is carried out using simulation and experiments. According to the comparative study, the proposed sensorless control outperforms conventional methods due to the inclusion of iron loss.