Design and experimental validation of a low THD standalone inverter using sinusoidal pulse width modulation for renewable energy applications
Abstract
The rapid integration of renewable energy sources, such as solar PV and wind power, requires development of high-quality and stable power output from standalone inverter systems. Standalone inverters can suffer from issues such as harmonic distortion, voltage fluctuation, poor power factor and losses incurred in converting direct current to alternating current, which can all affect power quality. To resolve these problems, an optimized inverter architecture is presented in this research which combines a full-bridge DC–DC type converter with an H-bridge inverter topology to produce a sinusoidal AC output for practical use. Pulse Width Modulation (PWM) switching technology is used in the design to accurately control semiconductor devices, which reduces the total harmonic distortion (THD) and enhances voltage stability. Further, a passive low pass filter is added at the output stage to reduce residual high-frequency harmonics, and thus the output is made sinusoidal and stable. The results of the performance investigations indicate that the proposed system successfully improves the power factor correction and overall efficiency of the system when compared to the conventional standalone inverter. The results of the simulated configuration show the reduction of THD values lower than the recommended ones, the voltage stability during the dynamic loading and the improvement of energy conversion efficiency. Based on these results, it is observed that the proposed inverter system is a suitable solution for applications that demand high-quality stand-alone renewable energy generation.