DESIGN AND ANALYSIS OF ELIMINATION OF HARMONICS USING WIND ENERGY CONVERSION SYSTEMS

In this paper we describe design and analysis of elimination of harmonics using wind energy conversion systems. Distortion of the voltage waveforms i.e. harmonics may cause overheating of neutral conductors and electrical distribution transformers, the malfunction of electronic equipment and the distortion of communication systems. Doubly Fed Induction Generator (DFIG) applied to wind energy conversion system (WECS) using variable speed operation is being used more frequently in wind turbine application. Variable speed systems have several advantages over the traditional method of operating wind turbines, such as the reduction of mechanical stress and an increase in energy capture. AC-DC converter is used to convert variable voltage from the DFIG to DC voltage, thereby producing DC power. The DC is converted back to AC that is appropriate for electrical utilizations in the grid. However, the use of converters introduces high intensity of low frequency current harmonic content into the power system. This leads to reduction in efficiency in WECS and also decreases the life span of the generator. A case study on a 9 MW wind turbine is used to explain Harmonic Mitigation in Wind Turbine Energy Conversion Systems. In this paper, harmonic voltage and current measurements performed at different points of a wind farm comprising six DFIG wind turbines are analyzed and their most important characteristics are discussed. It presents a comparative simulation study between with and without three phase harmonic filters applied to power system model connected to wind farm.