A single D.C. link Multi-level 42-sided polygonal Voltage Space Vector Generation with lower order harmonic suppression using Switched-Capacitive filter

In this work, a multi-level 42-sided polygonal space vector structure (SVS) for suppression of lower order harmonics for Open-End Induction Motor(OEIM) drive applications is proposed. The proposed power circuit topology consists of two inverters feeding an Open-End Induction Motor from either side. The main inverter fed with a single DC link providing active power for motor operation is switched at low switching frequency. The secondary inverter fed with a capacitive supply is switched at high frequency to suppress lower order harmonics upto 39th order, up to the base speed of operation allowing maximum utilization of the DC link. The advantages of lower order harmonic suppression in motor phase voltage, for polygonal space vector structures are combined with multi-level inverter topology. This results in lower switching losses in low frequency switching main inverter and low voltage secondary inverter. Use of a single DC link facilitates fourquadrant operation of the inverter. The proposed scheme is validated for steady state and dynamic performance by experimental results.