Multi objective optimization of performance of small size horizontal axis wind turbine based on NSGA-II technique

The aim of this research is to redesign and optimize of a rotor blade in small size wind turbine. The objective of such optimization is both running time and power coefficient. The aerodynamic modeling of rotor has been presented based on blade element momentum theory. The output parameters have been calculated subsequently. For validation the model is being compared with NREL phase VI turbine data. The technique of optimization is NSGA-II which is appropriately cope with multi objective problems. Variable are assumed to be pitch or twist angle and chord length and the cost function or performance index is composed of drive time and power. The max tip speed ratio and the bounds of variables are constraints. Based on the Pareto diagram it can be deduced by increasing the power, time would be influenced and degraded. It is recommended 3 points and all the characteristics are being drawn for each one. By choosing the compromise point, it is achievable to enhance the power coefficient by approximately 9 percent and to reduce the time of reaching nominal speed by approximately 10 percent