TY - JOUR T1 - Pitch Angle Control of a High-Power Wind Turbine Using Optimal Fractional-order PID Controller TT - کنترل زاویه گام یک توربین بادی توان بالا توسط کنترل‌کننده‌ PID مرتبه کسری بهینه JF - mdrsjrns JO - mdrsjrns VL - 17 IS - 3 UR - http://mme.modares.ac.ir/article-15-3808-en.html Y1 - 2017 SP - 167 EP - 176 KW - Wind turbine KW - Pitch Control KW - Fractional order controller KW - Differential Evolution (DE) KW - Firefly Algorithm (FA) KW - Particle Swarm Optimization (PSO) N2 - In this paper, an optimal Fractional-order Proportional-Integral-Derivative (FOPID) controller is proposed to control an offshore 5MW wind turbine’s pitch angle in above rated speed. The proposed pitch controller regulates the generator angular speed and consequently the generator power to its nominal value without any knowledge of the model. In order to find the parameters of the controller, a hybrid cost function is proposed, which consists of sum of absolute error signal and absolute rate of control signal in three different wind speeds. The wind speeds are chosen in the beginning, middle and at the end of the interval, thus, the optimized controller is able to show an acceptable performance in whole range of wind speeds, without any demand to nonlinear and complex controllers. To this end, the proposed cost function is minimized using three optimization algorithms: Differential Evolution (DE), Firefly algorithm and Particle Swarm Optimization (PSO). In order to evaluate the robustness of proposed FOPID, numerous wind profiles with different speeds and fluctuations are applied and the results are compared with the optimal integer order PID controller. The comparison demonstrates that the proposed FOPID has more effective performance and robustness than optimal integer order PID. M3 ER -