ON THE OPERATION OF VARIABLE FREQUENCY SYNCHRONOUS DRIVES

Abstract

The present work Is a recozd of the study carried out 4n sae aspects of the steady state operation of a a-inhronous drive fed with variable frequency supply.. In order to find out the best combination of applied Voltage with frequency for the dsited operational capabilities such as pull out power, current, power factor', stability etc., various modes of applied voltage and e,ot ttation adjustments hv• been considered. the possible effects of different design par eters of the main motor on the performance of the variable frequency drive were also looked into with a consideration of choosing their' suits -bie Values under the riouirq.1 operation. It has bean found that the current drawn by the rotor is independent of the supply frequency, if both, the applied voltage and induced 4mf are proportional to frequency and in this case the torque developed by the motor is also constant with respect to the frequency. lbr other applied voltage and induced of edjustmonts, the current drawn by motor to minimum at a certain value of frequency depending upon the values of the applied voltage and the induced anf.