Date of Award

Summer 2013

Document Type


Degree Name

Master of Science (MS)


Electrical and Computer Engineering

First Advisor

Demerdash, Nabeel A. O.

Second Advisor

Ionel, Dan M.

Third Advisor

Schneider, Susan C.


This thesis presents a control system for a 2MW direct-drive permanent magnet synchronous generator wind turbine system with the objectives to capture the optimal power from the wind and ensure a maximum efficiency for this system. Moreover, in order to eliminate the electrical speed sensor mounted on the rotor shaft of the PMSG to reduce the system hardware complexity and improve the reliability of the system, a sliding mode observer based PM rotor position and speed sensorless control algorithm is presented here.

The mathematical models for the wind turbine and the permanent magnet synchronous machine are first given in this thesis, and then optimal power control algorithms for this system are presented. The optimal tip speed ratio based maximum power point tracking control is utilized to ensure the maximum power capture for the system. The field oriented control algorithm is applied to control the speed of the PMSG with the reference of the wind speed. In the grid-side converter control, voltage oriented control algorithm is applied to regulate the active and reactive power injected into the power grid. What is more, sliding mode observer based sensorless control algorithm is also presented here. The simulation study is carried out based on MATLAB/Simulink to validate the proposed system control algorithms.