Roozbeh Bakhshi and Peter Sandborn
CALCE, Center for Advanced Life Cycle Engineering, Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20740, USA
Abstract:
Yaw error is the angle between
a turbine’s rotor central axis
and the wind flow. The presence of yaw error results in lower
power production from turbines. Y aw error also puts extra loads
on turbine components, which in turn lowers their reliability. In
this study we develop a stochastic model to calculate the average
capacity factor of a 50 turbine offshore wind farm and investigate
the effects of minimizing the yaw error on the capacity factor. In
this paper , we define the capacity factor in terms of energy
production, which is consistent with the common practice of
wind farms rather than the power production capacity factor
definition that is used in textbooks and research article s )). The
benefit of using the energy product ion is that it incorporates both
the power production improvements and downtime decreases .
For minimizing the yaw error, a nacelle mounted LIDAR is
used While the LIDAR is on a turbine, it collects wind speed
and direction data for a period of time, which is used to calculate
a correction bias for the yaw controller of the turbine , then it will
be moved to another turbine in the farm to perform the same task .
The results of our investigation shows that although the
improvements of the capacity factor are less than the theoretical
values, the extra income from the efficiency improvements is
larger than the cost of the LIDAR.