Evaluating the Effectiveness of the TAR Pulse Width Modulation Strategy for a 7-Level Inverter with Non-Uniform Source Voltages
S. Ramesh, Vijayakumar Madhaiyan, V. Arun
Abstract
This research presents a significant advancement in inverter technology, with the potential to greatly enhance voltage quality and reduce harmonic distortions in power systems. This research introduces a novel Pulse Width Modulation (PWM) strategy aimed at enhancing the operational efficiency of a 7-level Unequal Source Inverter (7LUSI) employing two DC sources in a 1:2 sequence. In contrast to the conventional Sinusoidal Pulse Width Modulation (SPWM) technique, this innovative PWM approach is intricately designed to improve voltage quality and overall harmonic spectra. The gate signal generation for this proposed PWM technique involves a modified PWM scheme that combines a trapezoidal waveform with a rectangular one (TAR) alongside a traditional triangular carrier waveform. These TAR level-shifted PWM schemes are utilized for generating triggering pulses for the 7LUSI. Various performance metrics are evaluated across different modulation indices, and comparative results are presented in contrast to conventional PWM methods. The findings consistently demonstrate the superior performance of the proposed TAR PWM method over traditional SPWM. The simulation study is conducted using MATLAB-SIMULINK as the primary computational tool. This research represents a significant advancement in inverter technology, offering substantial potential to enhance voltage quality and reduce harmonic distortions in power systems.