A 30-sided polygonal space vector structure with modular low voltage capacitor fed cascaded H bridge for IM drive

This paper proposes an induction motor (IM) drive scheme with a 30-sided polygonal space vector structure (SVS) using a single DC link. The proposed scheme eliminates the presence of 5th, 7th, 11th, 13th, 17th, 19th, 23rd and 25th order harmonics from the motor phase voltage over the entire modulation range. 30-sided polygonal SVS provides the advantage of increasing the linear modulation range till 99.63% of base speed. The proposed topology is a three phase two level inverter connected to two modular equal low voltage capacitor fed cascaded H bridges (CHBs). The former will act as the source of active power for the motor and latter will act as switched capacitive harmonic filter which filters lower order harmonic voltages from the motor phase voltage. The proposed scheme is validated through experimental results and is presented in this paper.