A comprehensive review of low-voltage-ride-through methods for fixed-speed wind power generators

This paper presents a comprehensive review of various techniques employed to enhance the low voltage ride through (LVRT) capability of the fixed-speed induction generators (FSIGs)-based wind turbines (WTs), which has a non-negligible 20% contribution of the existing wind energy in the world. As the FSIG-based WT system is directly connected to the grid with no power electronic interfaces, terminal voltage or reactive power output may not be precisely controlled. Thus, various LVRT strategies based on installation of the additional supporting technologies have been proposed in the literature. Although the various individual technologies are well documented, a comparative study of existing approaches has not been reported so far. This paper attempts to fill this void by providing a comprehensive analysis of these LVRT methods for FSIG-based WTs in terms of dynamic performance, controller complexity, and economic feasibility. A novel feature of this paper is to categorize LVRT capability enhancement approaches into three main groups depending on the connection configuration: series, shunt, and series-shunt (hybrid) connections and then discuss their advantages and limitations in detail. For verification purposes, several simulations are presented in MATLAB software to demonstrate and compare the reviewed LVRT schemes. Based on the simulated results, series connection dynamic voltage restorer (DVR) and shunt connection static synchronous compensators (STATCOM) are the highly efficient LVRT capability enhancement approaches.