TATCOM controller tuning to improve LVRT capability of grid connected wind power generating plants

Abstract

The global drive towards utilization of renewable and sustainable energy systems is being accelerated by the increase in energy demand, environmental concerns, and the depletion of fossil fuel reserves. Of the main renewable energy resources, wind power has been recording tremendous growth over the last two decades. Among wind turbine concepts, the Doubly Fed Induction Generator (DFIG) is the most popular wind turbine system due to its efficiency, separately controllable active and reactive power, and relatively low power rating of its power electronic converter. However, the DFIG is sensitive to power system faults since its stator is directly connected to the grid. With the high penetration level of wind power generating plants in grids, disconnecting Wind Power Plants (WPPs) during grid faults can affect stability of power systems. Power system operators have therefore set new grid codes which require wind farms to have Low Voltage Ride Through (LVRT) capability, hence contribute to system stability during grid faults. This paper utilizes a Static Synchronous Compensator (STATCOM) to enhance the LVRT capability of a 9MW DFIG based WPP during grid faults. The ability of the test system to ride through voltage sags on the grid side is investigated with incorporation of a conventional STATCOM and further with a Particle Swarm Optimization (PSO) tuned STATCOM. Simulations are carried out in MATLAB programming software, using SimScape toolbox. Results show that the STATCOM tuned using PSO results in an improved LVRT capability for the WPP due to the dynamic injection of reactive power. Keywords—LVRT, PSO, STATCOM, VSC.