The output power of a wind energy conversion system (WECS) is maximized if the wind rotor is driven at an optimal rotational speed for a particular wind speed. To achieve this, a Maximum Power Point Tracking (MPPT) controller is usually used. A successful implementation of the MPPT controller requires knowledge of the turbine dynamics and instantaneous measurements of the wind speed and rotor speed. To obtain the optimal operating point, rotor-generator characteristics should be known and these are different from one system to another. Therefore, there is a need for an efficient universal MPPT controller for WECS to operate without predetermined characteristics. MPPT control of WECSs becomes difficult due to fluctuation of wind speed and wind rotor inertia. This issue is analyzed in the paper, and an Adaptive Filter together with a Fuzzy Logic based MPPT controller suitable for small-scale WECSs is proposed. The proposed controller can be implemented without predetermined WECS characteristics.