Abstract
Abstract-This article presents an investigation of four-switch inverter performance fed three-phase induction motor drives. Speed estimation is based on fundamental wave models using a model reference adaptive system as a speed estimator technique. The motor is fed from a four-switch three-phase inverter. A comparative study for sensorless speed estimation using a four-switch three-phase inverter, and a six-switch inverter is simulated and experimentally investigated at different operating conditions. Also, a comparison of system performance based on the four-switch inverter and conventional six-switch inverter in terms of speed response and total harmonic distortion of stator currents is presented. Experimental and simulation results at different points of operation are presented, verifying the robustness of sensorless speed estimation at different load levels. Sensorless speed estimation based on the four-switch three-phase inverter is quite acceptable considering its speed response.