Study On Multidisciplinary Reliability Optimization Design Method In Concept Design For Wind Turbine

As market competition intensified, the wind energy industry had a higherdemand on reliability and cost control for wind turbine. Developers hope to estimatethe cost and reduce cost in early age of product design (concept design) to increasemarket competitiveness under conditions to ensure that products meet theperformance and reliability.A range of parameters should be identified in concept design for wind turbine,for example: rotor diameter, tip speed ratio and tower height. But in fact theseparameters were coupled with each other. The horizontal axis variable speed constantfrequency variable pitch wind turbine was studied as an object in this paper, andmulti-disciplinary reliability optimization design method was researched for the windturbine concept design phase. The main results are as follows:（1）The multi-disciplinary reliability design model was established for windturbine and the lowest unit cost of power generation was considered as the design goal.The effects between basic design variables, the main components and the design goalswere analyzed and multi-disciplinary reliability solution strategy was researched forwind turbine.（2）Aerodynamic performance was calculated for wind turbine’s blades basedon blade element momentum theory, and the blade chord length and twist angle wasoptimized. Wind turbine generating capacity estimation model was established forconcept design phase, according to the wind turbine’s blade aerodynamic performance,combined with wind speed distribution model and speed-height model, the effect thatseveral key parameters on the annual energy production were studied.（3）Concept design reliability optimization model was established for windturbine gearbox, and calculated the fatigue reliability with the center point method.Multi-objective optimization was calculated for the target of minimal gear and gear box’s volume, and different transmission scheme was optimized and compared.(4) Wind turbine’s tower concept design reliability optimization wasestablished, simplified the tower mechanical model and its main failure mode. Thetower wall thickness was optimized with the design goal of the minimum tower cost,and analyze the effect of tower height on tower cost and annual energy productioncombined with the annual generating capacity estimation model.(5) The reliability design problem was studied for wind turbine’s blade, towerand gearbox at concept design stage, the optimization was performed with the designgoal of the lowest total cost, and at last get the best reliability for blade, tower, andgearbox.(6) A certain type of1.5MW wind turbine was selected as an example for themulti-disciplinary reliability optimization design of wind turbine at concept designstage,and used iSIGHT and Matlab to solve that problem. The calculation resultsshowed that the multi-disciplinary reliability algorithm can increase the wind energyproduction, reduce the unit cost of power generation effectively, and the marketcompetitiveness of products was improved.