I. Introduction
Advances in wind turbine technology [1] and rich wind resources in many areas improve prospects for the wind power industry [2], which motivates the analysis of wind power generation and wind turbine performance. However, because turbines are distributed over a wide area in a wind farm, the power generated by each is usually different due to variations in wind direction and speed. In fact, measured wind data is seldom identical to that seen at the generator for a variety of reasons, including the expense of obtaining and maintaining that data, and topographical constraints.