Variable speed control of wind turbines via memory-based firing angle sequence adjustment

Maximum electric power extraction out of available wind power is directly linked to advanced variable speed wind turbine control. The paper presents a memory-based method for variable speed adjustment of wind energy conversion systems. The fundamental idea behind the method is to use certain memorized information (i.e., current rotor speed tracking error, most recent speed tracking error, and previous control experience) to directly modify the firing angle control command sequences. The salient feature of the proposed approach lies in its simplicity in design and implementation. Furthermore, the total required memory space does not grow with time and is much smaller than most existing learning control methods. It is shown that this method, when applied to firing angle control of wind turbines, is able to ensure rotor speed tracking in the presence of varying operation conditions, as verified via computer simulation.