해상 풍력발전단지 내의 후류 그늘효과가 공력성능에 미치는 영향 분석

Abstract

Offshore wind farm system has more advantage than onshore wind farm system. However, there is a disadvantage in environmental variables like ocean wave and tidal current. If we consider these environmental variables and wake stream effect in complex, more compositive problems and uncertainty will arise from complex layout design step. Therefore, it needs detailed consideration of installation site’s marine environment and compositive phenomenon by wake stream to improve performance of wind farm system and reduce investigation cost. As mentioned earlier, there will be an analysis in 2 sections to make accuracy of initial design high. One is effect at aerodynamic performance using sorts of wake shadow effect in complex, the other is circumstance characteristic in complex. CFD analysis is in basic, and this research strengthen the advantage and make up for the disadvantage, using VBM(Virtual Blade Method) utilized momentum source in actuator disc. Before this analysis, it proved the validity of VBM analysis and NREL baseline 5MW through CASE 1 and CASE 2. This analysis consists of CASE 3 that is affected by wake shadow effect from front and CASE 4 that installed wind turbine at upper region between 2 wind turbines in lower region. After analysis, it could find there is not only wind power amount by strong wake stream came from upper region generator but also effect of big repeated load in CASE 3. From CASE 4, there was no effect of wake stream from upper region, but repeated load affected cycle and performance in a roundabout way. Through result of research, it could be proven that compositive flow (like wake shadow effect arised in complex) affects at initial layout design. Also, virtual blade model considering fast analysis of numerical analysis like BET and compositive flow analysis ability of CFD is available at real wind power plant complex analysis and design and has many advantages. Because wind energy is sensitive at environmental variables and cause big variability to turbulent component, initial layout design that considered environmental variables and wake shadow effect can reduce uncertainty of design.