A modified PWM technique to improve total harmonic distortion of Multilevel Inverter

In this study, a modified carrier is proposed to generate PWM gating signal. Proposed PWM method reduces total harmonic distortion (THD) of the output voltage of inverter up to 5.8% than the traditional triangular carrier based PWM. Major harmonic components in output voltage are less in magnitude when proposed PWM technique is applied to inverter. Fundamental component of output voltage is also higher in proposed PWM method for all modulation index and frequency ratio. Performance of proposed modified carrier based PWM is evaluated by MATLAB simulation for single phase 4-cells 9-levels cascaded H-bridge MLI.