Harmonic distorted modified triangular wave pulse width modulation for multilevel converters

This article proposes an improved harmonic distorted modified triangular wave modulating signal for carrier-based modulation of multilevel converters. For the development of this signal, a fundamental frequency triangular signal and three times the fundamental frequency sinusoidal signal are used. The combined signal is clipped off at certain point to obtain the proposed modulating signal. The design of the signal is done to keep output total harmonic distortion of the converter low, reduce the low order harmonics of the converter output voltage and current for efficient filtering, increase the fundamental voltage gain to ensure the effective dc voltage utilization and to reduce switching loss to improve the efficiency scenario of the converter. High frequency phase disposed carrier signals are utilized for the modulation with the proposed signal. The suggested modulation scheme is applied to 5-level and 11-level cascaded H-bridge converter to demonstrate the claimed performance over other existing modulation methods. All the simulation works are done in MATLAB/Simulink environment.