2 MW급 대형 수평축 풍력발전 시스템을 위한 필라멘트 와인딩 복합재 타워의 최적설계에 관한 연구

Abstract

Humankind has used wind energy through the several forms for several thousand years. The wind turbine system which has long history like that is the most economical new renewable energy technology until now, but it completely depends on the wind. So, wind turbine system's quantity and system's efficiency are somewhat low. However, experiences, academic theories and new technologies in the past were intensively invested to wind turbine system because of the recent exhaustion of fossil fuel, so lots of studies from small scaled wind turbine system to large wind turbine system of MW class are conducted. As the wind turbine system becomes large, blade and tower are also becoming large. In case of blade, studies on the weight lightening with composite are conducted actively. But, for tower, studies on the application of composite are insufficient. Wind turbine system tower is simpler than other mechanical elements, but its unit cost is so high enough to share 20~25% of the whole cost of wind turbine system. Therefore, it's important to develop tower which is competitive in price. In case of tower applied by composite, its production price can be reduced if comparing existing steel towers through the weight lightening and simple manufacturing process in comparison with existing steel towers. And, it can be established more easily than existing towers through the simplification of moving and establishment. As the result of analyzing domestic and international studying, tower applied by steel material is studied actively on designing and establishment of optimal thickness. But, studies on towers applied by composite are insufficient. This study conducted optimal designing for wind turbine system tower of 2 MW and MW-grade horizontal axis with glass fiber/epoxy. Through the load analysis, optimal designing was conducted by applying composite through the optimal process, after the pre-designing applied by steel. During the designing of tower structure, wind load, blade reaction, weight by nacelle, tower, etc. were considered. The optimal layer pattern was decided by optimal process and optimal thickness was decided by considering buckling, stress, displacement, etc. For the model designed, structural safety was examined by commercial finite element program, MSC.NASTRAN/PATRAN, and all of requirements for designing were satisfied. Also, miniature model was manufactured by same method and then, outermost distribution of stress was confirmed. In this study suggested the procedure to design large-scaled wind turbine system tower applied by composite, conducted optimal designing and confirmed that the designed tower satisfied the designing requirements.