A Novel Multi-Level SVPWM Scheme for High Power Induction Motor Drive Applications

In this paper, a multi-level inverter (MLI) topology for an OEWIM (Open-End Winding Induction Motor) drive is proposed. In this topology, one end of OEWIM is fed by a FC based hybrid 5-level inverter and other end is connected to a symmetrical 5-level inverter. The hybrid 5-level inverter is achieved by cascading a 3-level flying capacitor inverter with capacitor fed H-bridge. The symmetrical 5-level inverter is obtained by cascade connection of four 2-level inverters with equal DC-link voltages. The combined effect of 5-level hybrid and 5-level symmetrical inverters generate 25 distinct levels in the phase voltage. In this proposed topology, a total of 3,43,000 space phasor combinations are accessible; hence using switching redundancies, the capacitor voltages can be maintained at desired levels. The proposed topology requires only 48 switching devices, as compared to conventional topologies that require 144 switches and fully eliminates the requirement of clamping diodes, which are required in NPC inverter. It, also, requires only 6 capacitors unlike to 828 capacitors required in 25-level FC inverter and 5 DC power supply sources as compared to 25-level CHB inverter that require 36 DC power supply sources. Hardware-in-loop (HIL) validation of simulation results is carried out to evaluate the performance of the proposed inverter and results are presented.