New hybrid cascade multilevel inverter with less number of switches

Abstract

Multilevel Inverters (MLI) is generally employed to synthesis a desired voltage waveform.The power quality of multilevel inverter is improved as the number of levels increases at the output. However, it causes to the increasing number of switching devices and dc voltage sources, and increases the cost and control complexity and tends to reduce the overall reliability and efficiency. In this paper a new topology of Hybrid Cascade Multilevel inverter (HCMLI) is proposed to improve the multilevel inverter performance by compensating these disadvantages. This topology has less number of power switches compared to that of conventional multilevel inverters. The proposed new structure consists of two parts one is basic module and another one is H-Bridge. Basic module is used to produce all positive output levels, and negative and zero levels are achieved by H-Bridge. Asymmetric configuration of MLI will result the higher numbers of steps with the same number of switches as symmetric configuration of MLI. MATLAB/Simulink environment is used to simulate and validate the results of Symmetric and Asymmetric proposed HCMLI for 11 level and 19 levels respectively. keywords: Multilevel Inverter, Symmetric MLI, Asymmetric MLI, THD, CHB.I.