Vector control of a three-phase parallel connected two motor single inverter speed sensorless drive

Abstract

This paper presents the performance characteristics of two induction motors of the same parameters and ratings connected in parallel and fed by a single inverter. A nature observer is employed to estimate the rotor speeds and rotor fluxes of both induction motors. It also estimates the load torques of both the motors by load torque adaptation. Under unbalanced load conditions, the speed difference between the two induction motors is reduced by considering the average and differential motor parameters and currents. Mean rotor flux is maintained constant by a rotor flux control scheme and the estimation of rotor angle is carried out by direct vector control technique. The prototype experimental setup is made for validating the proposed method and the experimental results are demonstrated for various running conditions. The natural observer algorithm for speed and torque estimation is executed by TMS320F2812 DSP controller.