PWM technique for current source multilevel inverter

Current source inverters (CSI) are mainly employed where fast dynamic performance is not required such as in fans and pumps (Wu. B 2005). Simpler topology, absence of electrolytic capacitors, inherent four quadrant operation, reliable overcurrent and short-circuit protection (Wu B. et al 2008) features the advantage of CSI. The influence of current source inverters in drive applications is advantageous, as it produces low distortion in voltage and current, increasing the motor efficiency with reduced common mode voltage causing lower stress to the bearing in comparison with voltage source inverters (Delli Colli. et al 2005). A comparative analysis of the two drive topologies namely VSI and CSI in various multi-phase design configurations was carried out highlighting how the performance of the CSI drive could be remarkably improved by resorting the motor windings with more than six phases (Castellan S. Sulligoi G. Tessarolo A 2008).