నైరూప్య

EFFICIENCY ANALYSIS OF INDIRECT VECTOR CONTROLLED THREE PHASE INDUCTION MOTOR DRIVE

Seena Thomas, Rinu Alice Koshy

This paper analyses the overall system level efficiency of an indirect vector controlled induction motor drive. Both the induction motor losses and inverter losses are considered. A 5.4-hp induction motor drive is simulated to analyse the efficiency under different operating conditions of the drive. The variation of efficiency under load change and speed change is observed. Simulation results show that efficiency increases as the operation of induction motor drive shifts from unrated to rated conditions. At light loads, the iron losses in the induction motor are significant. The efficiency of the motor can be increased by keeping the flux level below the rated value. Also the influence of hysteresis band on the switching losses of the inverter is analysed. The results suggest that, for efficient operation of the drive, an optimum combination of the various control variables are required.