A NEW MULTILEVEL INVERTER TOPOLOGY TO INTEGRATE WIND-SOLAR HYBRID SYSTEM WITHOUT A COMMON DC BUS

Abstract

Multilevel level inverters are becoming widely popular due to their capability to synthesize medium or high voltage at its terminal with matured low voltage components. Cascaded H-Bridge inverter is one of the three basic topologies of multilevel inverter family known for its modularity. The conventional H-Bridge topology comprises of a basic unit with single independent source and four switches. This makes the topology bulky for higher voltage levels and steps. In this paper a new basic unit for cascaded H- bridge multilevel inverter has been proposed. The modularity of the proposed basic unit can be utilized to integrate wind and solar generation systems without a common DC bus. Its performance is compared with the other topologies available in the literature in the aspects of required number of switches, gate drivers and diodes. The Total harmonic Distortion (THD) in the output voltage and conversion losses are estimated. The basic unit in symmetric mode has been simulated using MATLAB Simulink software package and the obtained results are justified with a hardware prototype.