Investigation on Symmetrical Three Phase Hybrid Cascaded Multilevel Inverter With Reduced Number of Switches

Vol. 6 No. 3

Year: 2013

 
Issue: Jan-Mar

Title : Investigation on Symmetrical Three Phase Hybrid Cascaded Multilevel Inverter With Reduced Number of Switches

Author Name : V. Vidhya, C.R.Balamurugan , S.P.Natarajan

Synopsis :

This work proposes investigation on symmetrical three phase hybrid cascaded multilevel inverter topology with reduced number of switches and is able to create five level output. The main advantage of the proposed work is to reduce the number of switches when compared to the Cascaded Multi Level Inverter (CMLI). The reduced number of switches reduces the switching losses and improves the efficiency of the inverter. The variation of Total Harmonic Distortion (THD) in the inverter output voltage is observed for various modulation indices. Simulation is performed using MATLAB-SIMULINK. By comparing the various PWM techniques, such as COPWM-1, COPWM-2, COPWM-3 and COPWM-4, it is observed that Carrier Overlapping Pulse Width Modulation-3 (COPWM-3) provides output with relatively low distortion for all strategies and better DC bus utilization is obtained in (COPWM-1) and also comparing the various variable amplitude techniques, such as  VACOPWM-1, VACOPWM-2, VACOPWM-3 and VACOPWM-4, it is observed that Variable Amplitude Carrier Overlapping Pulse Width Modulation-3 (VACOPWM-3) provides output with relatively low distortion for all strategies and better DC bus utilization. Finally comparing the various PWM techniques with  the various variable amplitude techniques, It is observed that Variable Amplitude Carrier Overlapping Pulse Width Modulation-3 (VACOPWM-3) provides output with relatively low distortion for all strategies and better DC bus utilization is obtained in (VACOPWM-2).