Analysis and Implementation of Parallel Connected Two-Induction Motor Single-Inverter Drive by Direct Vector Control for Industrial Application

Sensorless-based direct vector control techniques are widely used for three-phase induction motor drive, whereas in case of multiple-motor control, it becomes intensively complicated and very few research articles in support to industrial applications were found. A straight-forward direct vector control with sensorless operation for parallel connected two similar-rated induction motors driven by single three-phase inverter is proposed and verified numerically by simulation software test under balanced and unbalanced conditions. The proposed control algorithm adapts the natural observer to estimate the rotor speed, rotor flux, and load torque of both motors. Simulation results along with theoretical background provided in this paper confirm the feasibility of operation of the ac motors and proves reliability for industrial applications.