Implementation of dspace based new hybrid pwm strategies for single phase seven level cascaded asymmetrical inverter

Multi Carrier Based Pulse Width Modulation (MCBPWM) technique have been used widely for switching of multilevel inverters due to simplicity and reduced computational requirements than the Space Vector Modulation (SVM). New hybrid MCBPWM techniques for the chosen single phase Asymmetrical Multi Level Inverter (AMLI) with Trapezoidal Amalgamated Reference (TAR) are proposed in this paper. The proposed Phase Disposition (PD), Phase Opposition Disposition (POD), Alternate Phase Opposition Disposition (APOD) and Carrier Overlapping (CO) Pulse Width Modulation (PWM) strategies are developed with triangular carrier above zero axis and rectified sine carrier below zero axis. The triggering pulses are generated using the dSPACE dS1103 hardware and front end tool control desk with MATLAB/SIMULINK/Real Time Interface (RTI) environment. The performance indices used are Total Harmonic Distortion (THD), Form factor (FF), Distortion factor (DF) and Root Mean Square (RMS) value of output voltage. It is observed that COPWM provides relatively better DC bus utilization and creates relatively lesser distortion for modulation index ma=0.7-1.