An approach to voltage quality enhancement in wind energy conversion systems

Abstract

Given the obstacles posed by legislation, pollution, and the depletion of nonrenewable energy sources, electricity production is progressively turning toward renewable energy sources such as the sun and wind. Wind energy looks to account for a considerable proportion of power production in developed nations relative to other renewable energy sources. As energy demand grows, the incorporation of renewable energy into the nation's electrical systems is expanding considerably. This has shown a variety of benefits, including meeting demand increases, providing energy security, and contributing to the decarbonization of the energy system. However, as the usage of renewable energy sources increases, the power system becomes more unstable, especially in the event of grid faults. Wind farms must comply with grid code standards to avoid the collapse of the power system. External electrical grid factors, such as the unpredictability of the wind and power electronics in wind turbine applications, may affect power quality. Even though there have been significant technical advancements in wind energy production on a worldwide scale, transmission system operators continue to be concerned about power quality and system stability. Consequently, evaluating the effects of power quality is vital and necessary. Transmission system operators developed rules and grid code standards to analyze the power quality of wind energy prior to incorporating it into the grid. The IEC 61400-21 standard is one of the most widely used and well-known requirements for describing the power quality of wind turbines. The primary focus of this dissertation is voltage quality, one of the power quality issues that impede the connection of wind energy plants to the electrical grid. The study evaluates the quality characteristics of harmonic distortion, voltage flickering, voltage fluctuation, voltage unbalance, voltage sag, voltage swell, undervoltage, and overvoltage. In addition, a technique for enhancing voltage quality was evaluated in order to mitigate the consequences of voltage quality issues during any occurrence that might disrupt the electrical system. In order to enhance the efficiency of power transmission in power systems, the Flexible AC Transmission System (FACTS) controllers Static VAR Compensator (SVC) and Static Synchronous Compensator (STATCOM) are widely used. Wind energy conversion systems (WECS) have used FACTS controllers to enhance their transient stability, voltage quality, and regulation. When SVC and STATCOM are connected to the electrical grid, simulation results in the MATLAB/Simulink environment indicate that their reactive power assistance to the electrical grid during fault situations has a significant impact on the voltage profile and reduces the recovery time following any fault. STATCOM operated somewhat faster than SVC under fault circumstances and supplied more reactive power during severe faults when the bus voltage was lower.