Steady State Performance of Permanent Magnet Synchronous Motors FED from Delta Modulated Inverters

This paper presents an analysis and performance of permanent magnet (PM) synchronous motors fed from a delta modulated inverter. From the analysis and implementation it is found that, besides easy implementation, the delta modulated inverter has lower harmonic contents and the inherent constant fundamental voltage to frequency ratio control. The P. M. motor's requirement of a constant V/f characteristics during run up is met by the delta modulated inverter. This ensures a smooth start up, and constant torque and constant power profiles in the P. M. motor performance characteristics during steady state operation. Analytical expressions for the motor terminal quantities are given. Validity of the analysis is confirmed experimentally.