RT20 | Realization of Hybrid Nine-Level Inverter Using RT-LAB in HIL

​In this presentation a novel nine-level inverter topology for an open-end winding IM, using a two-level and hybrid five-level inverter has been discussed. The hybrid five-level inverter is realized by cascading a three-level FC inverter and capacitor fed H-bridges in each phase. The proposed topology requires less of components as compared to existing topologies of nine-level inverter. Modified LSPWM based control scheme is used which offers less switching of the devices at lower speed range. It has been shown that switching occurs in two-level inverter only for half of the fundamental period; this reduces the switching losses and improves overall efficiency of system. The entire system is experimentally verified on 1.5kW open-end winding induction motor for the entire modulation range in V/f control mode, at no-load in Rt-Lab environment. effectiveness of the capacitor balancing algorithm is experimentally tested and verified. The stable operation of the inverter for various modulation indices and stability of the inverter voltage levels during sudden acceleration have been validated experimentally. The experimental results show the potential of the discussed inverter topology for industrial drive applications.