Assessment Among Single And Three Phase 28-echelon Cascaded Multilevel Inverter With Three H-bridge Inverter Modules

The function of this work is to minimize total harmonics distortion and number of switch and improve level in output voltage waveform. In conventional method, needed five H-bridge units to used 11-echelon inverter but in this proposed method for a 28-echelon cascaded H-bridge multilevel inverter required only three H-bridge unit per phase. By using this proposed idea it reduces the total harmonics distortion through the appending of echelons. In this work both single phase and three phase total harmonics distortion and number of switch has reduced. Simulation result is providing for 14-echelon and 28-echelon cascaded H-bridge multilevel inverter to validate the accuracy of computational result. Single phase and three phase simulation result was 14-echelon cascaded H-bridge multilevel inverter the total harmonics distortion level is 16.12%. The simulation result gives the total harmonic distortion level for single phase and three phase 28-echelon cascaded H-bridge multilevel inverter that is 12.61%. Therefore the total harmonic distortion in 28-echelon inverter is less by 3.51% with respect to 14-echelon inverter. Comparison of result with active harmonics reduction techniques indicates that the total harmonics distortion and switching frequency of output voltage reduced dramatically.