Performance Comparison between Synchronous Condenser and Static VAR Compensator to Improve System Strength in a Wind Dominated Power Grid

Abstract

Wind power has now recognized as a mainstream electriciy generation source because of its zero fuel cost and high CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> abatement potential. However, rapid increase of wind energy integration introduces a number of challenges in terms of security, reliability and stability to the power grid. These issues become more noticeable during prolific wind penetration levels. Modern converter based Type-3 and Type-4 Wind Turbine Generator (WTGs) replaces the synchronous generators from the generation sources. These WTGs are seperated from the grid by power electronic devices. As a result, they cannot deliver enough short-circuit current when a fault is occurred. This results a weaker system strength. A minimum level of system strength is necessary to ensure successful fault ride through for wind farms. In order to improve system strength, various fault current contribuiting devices such as synchronous condensers, Static VAR Compensators (SVCs) can be deployed. However, perfromance of these devices vary with their size and technology and no comparative study has been found in the existing literatures on fault current contribution of these devices. This paper shows the performance comparison between synchronous condensers and SVCs on grid system strength in a wind dominated power grid. The findings of the study also provides useful indication to further research on the installation of these devices from financial aspects.