Power Quality Analysis of Solar PV/Micro-Hydro/Wind Renewable Energy Systems for Isolated Area

Abstract

Renewable energy systems are technologically matured and promising to replace conventional fossil fuel energy systems that produce greenhouse gas emissions. However, renewable energy generation also encounters problems such as power quality issues. The intermittency nature of renewable energy resources, such as varying irradiance of solar PV and wind speed of wind energy in an isolated area, has potentially led to voltage fluctuations on the source side and generate harmonic distortion due to the inverter switching process. The main objective of this paper is to analyze the power quality issues of a standalone solar photovoltaic/microhydro/wind energy system. This study adopts an off-grid solar photovoltaic/micro-hydro system in Teluk Sumbang, East Borneo, Indonesia, as a case study to construct a renewable energy system. For this purpose, voltage fluctuations may vary about ±10% of its nominal value according to IEC standards. Total harmonic distortion (THD) indices according to IEEE standard 519-2014 are used. The simulation model is developed and observed using MATLAB/Simulink environment. A three-phase inverter with closed-loop voltage control insulated gate bipolar transistor inverter is applied to convert DC to AC and supply power to AC loads. LC and LCL filters use to minimize the harmonics distortion injected by the inverter switching process. Results show that under intermittency nature of renewable energy sources leads to power quality issues concerning voltage fluctuation. THD of voltage and current of the systems are less than 8%, and it is still within an acceptable range in IEEE standard limitation.