A Bus-Clamping Pulse Width Modulation Method for a Dodecagonal Space Vector generation scheme for 3-phase Open-End Winding Induction Motor Drives

摘要

Obtaining better harmonic profile at relatively lower switching frequencies is one of the key tasks in the present day power electronics world. Several pulse width modulation (PWM) techniques have been developed earlier in time, to reduce the harmonic content from the output of the inverter. Dodecagonal space vector generation scheme is one of them, which eliminates the most dominant lower order harmonics for the entire modulation range. In this paper, bus-clamping PWM technique is developed for a dodecagonal space vector structure, which is capable of reducing the switching frequency in the linear modulation range compared to conventional dodecagonal space vector technique. In order to compare the performance of the PWM schemes in terms of harmonic content, analytical expressions are derived based on the notion of stator flux ripple in the space vector domain. The results are verified by simulating and comparing the voltage harmonic distortion of the scheme with conventional dodecagonal scheme in terms of voltage weighted total harmonic distortion (V_(WTHD)) and current total harmonic distortion (I_(THD)).