New Approach to Design of Multilevel Inverter with Reduced Number of Switches along with Fault Detection

Multilevel inverter is a type of converter which gives almost sinusoidal output by increasing number of output levels. This is widely used in industry and electric drive systems because of its medium and high voltage output including the advantages like low switching stress and low total harmonic distortion (THD). In this paper a symmetrical topology of 9-level inverter is proposed and fault across the switches are detected. This topology consists of 4 unidirectional switches and 4 bidirectional switches. In this topology only 3 switches are conducted to obtain a particular level. With the usage of bidirectional switches power density reduces significantly along with rise in efficiency. Another advantage of this topology is that left half of the topology is responsible for level generation and the right half of the topology will take care of polarity of output voltage across load terminals. This topology is verified in MATLAB/Simulink environment.