Design and Simulation of 9-Level Hybrid Cascaded H-Bridge Multilevel Inverter with Reduced Components

Abstract

The Multilevel Inverter (MLI) is attracting the researchers in industries and in academics for medium voltage, high power control. The desired output of MLI is synthesized in form of stepped waveforms with lower harmonics. Several conventional topologies have been anticipated to realize the MLI. The demerit of conventional MLIs is that it requires more number of components which in turn increase the complexity of gate pulse generation. As a result the overall cost of MLI will increase. To overcome these demerits, a hybrid topology is suggested in this paper. Compared to the conventional MLIs, the number of dc sources, power switching devices, converter cost and space required is considerably reduced with the increase in number of steps in output voltage. This paper includes the design and simulation of the hybrid converter with different types of PWM techniques. This hybrid converter is a combination of T-Type single phase inverter [6] and H-Bridge module with sub switches [8]. In this hybrid topology, Switching functions are improved in easy way. Operational principle is demonstrated with right figures and tables. High quality output voltage wave is obtained in simulation results. It reduces dv/dt stresses experienced by switches and also output voltage harmonic component are low.