Small-scale wind turbine control in high-speed wind conditions: A review

The operation of small-scale wind turbines in high-speed wind conditions continues to pose a number of problems to this industry, turbine owners, and communities, over which this paper presents a comprehensive discussion of the operation and control of these energy conversion systems under such challenging conditions. A pitch control mechanism is widely used in mediumand large-scale wind turbines; however, such a complex mechanism is too expensive for small wind turbines. Due to these critical conditions and the avoidance of higher costs associated with electromechanical systems, electrical stall control strategies integrated with maximum power point tracking (MPPT) algorithms have become well known as a method for controlling wind turbine operation in various weather conditions, from low- to high-speed winds. During low- and mediumspeed wind conditions, the wind turbine follows the MPPT control loop to extract the maximum amount of energy from the wind, while capturing the maximum power is not achievable in high-speed wind conditions by increasing the wind speed, and the control loop has to be switched to stall mode to handle such conditions, under which this paper reviews the existing stall -control techniques in a comprehensive manner.