Voltage Fluctuation Correction for Renewable Energy Systems in Distribution Network

Renewable energies are becoming an important element of modern society, but integration into the power grid poses critical challenges. Power quality is an important aspect when integrating renewable energy. The main power quality concerns are 1) Voltage and frequency fluctuations caused by uncontrollable fluctuations in renewable energy sources. The variable nature of renewable energy sources due to constantly changing weather conditions results in voltage and frequency fluctuations in interconnected grids. 2) Harmonics introduced by power electronics equipment used to generate renewable energy. If the penetration rate of renewable energy is high, the effects of harmonics can be significant. This article comprehensively reviews the new power quality challenges of integrating renewable energies. It summarizes wind turbines and PV systems, their power quality issues, and existing approaches to improving power quality. A method is reviewed, and the control technology-based power quality improvement proposed using a voltage restorer. Future research directions are thus recommended based on the result shown in this paper and thereby help to mitigate power quality challenges for renewable energy integration.