Wind energy conversion systems (WECSs) can extract maximum power by controlling the wind turbine rotational speed. This study presents a novel sensorless maximum power extraction control for small-scale WECS using a permanent magnet synchronous generator (PMSG), to improve the maximum power extraction. The proposed method uses the output voltage and current of a rectifier to determine the duty cycle of the boost converter, without requiring the wind speed information and turbine characteristics. The step size of the duty cycle is changed adaptively, based on the difference between the rectifier output power and the previous duty cycle to obtain fast convergence, until the maximum power point is attained. The performance of the proposed sensorless maximum power extraction control is evaluated both by simulation, using PowerSIM and laboratory experiments, for variable wind speed conditions. The proposed maximum power extraction controller has a simple structure, low cost, and a good response to wind speed variations. The proposed method can extract a higher maximum power and has a higher efficiency of 93.87%, than the conventional perturb and observe method.