Methods in wind power prediction & forecasting

Globally on-shore wind power has seen considerable growth in all grid systems. In the coming decade off-shore wind power is also expected to expand rapidly. Wind power is variable and intermittent over various time scales because it is weather dependent. Therefore wind power integration into traditional grids needs additional power system and electricity market planning and management for system balancing. This extra system balancing means that there is additional system costs associated with wind power assimilation. Wind power forecasting and prediction methods are used by system operators to plan unit commitment, scheduling and dispatch and by electricity traders and wind farm owners to maximize profit. Accurate wind power forecasting and prediction has numerous challenges. This paper presents a study of the existing and possible future methods used in wind power forecasting and prediction for both on-shore and off-shore wind farms.

Retrodirective Rotman Lens Constraining Factors

The mechanism by which a retrodirective Rotman lens operates is examined theoretically and prediction is compared with measurement. By deriving the reflection matrix based on the phase delay relationship between the beam ports and the array ports we show that if the phase delay difference between neighbouring ports is constrained in a particular way that the reflection matrix becomes an inverse diagonal matrix and the Rotman lens functions as a Van Atta Array hence can perform retrodirective reflection. Further, the primary factors governing the bandwidth and beam pointing error of the lens are elaborated.