Performance Comparison of Two Wind Turbine Generator Systems Having Two Types of Control Methods

Abstract

The purpose of this paper is to gain a greater understanding of the performance of practical wind turbine generating systems with differing output power controllers and controlling means for wind turbine speed. Use of operating wind turbines is practical for investigating the relations of wind speed, output power, and electric parameters including voltage and current under respective power generating conditions. Subjected wind turbines, both equipped with an asynchronous power generator, are located at two sites and are defined as *Wind turbine A and Wind turbine B in this study, respectively. Their performance differences are examined by measuring wind speed and electric parameters. Wind turbine A controls the output power by varying blade angles while a wound-rotor induction geneator controls the turbine speed. Wind turbine B performs output power control by stalling the blades, and a squirrel-cage induction generator with two speeds by change of poles is adopted for the turbine speed control. The study suggests that both wind turbines have a clear linkage between current and output power fluctuations. Comparison of the fluctuations to wind speed fluctuation, although they are triggered primarily by wind speed fluctuation, clearly indicates the specific behaviors inherent to the respective turbine control mechanisms.