Abstract

Recently, there is a growing interest in the use of wind energy in buildings environment for distributed generation systems. However, the prediction of the wind speed and energy in such environment is difficult, due to the roughness and the frictional effects which reduce the wind speed close to the ground. Moreover, the adjacent buildings affect the wind regime around a specific building in the urban environment. Therefore, a method for appropriate estimating of the wind speed and energy over the buildings’ roofs is required for the initial stages of the wind energy development in the urban environment.
This thesis provides a novel method of estimating the wind speed and energy using a wind tunnel. The method has been validated using two case studies, homogeneous and non-homogeneous terrain.
The Permanent Magnet Generator (PMG) is preferred in small Wind Energy Conversion System (WECS) for stand-alone and remote areas. A new technique to control the flux of the PMG for WECS applications has been developed and used in this thesis for voltage regulation purposes. By selecting a suitable value of d-axis current, the terminal voltage of the PM generator can be regulated for variable wind speed. Consequently, the terminal voltage across the load is also regulated. No special mechanical techniques or additional electromagnetic coils are used for this purpose.
The effect of the PMG flux control on the reactive power compensating capability for a variable inductive load has also been studied for WECS applications.
The case study presented in this thesis shows how the reactive power consumed by the load was compensated using the flux control operation of the system. The controller shows highly effective response during steady state and transient.
A flux controller of a permanent magnet variable flux machine (PM-VFM) has also been designed and presented in the thesis for voltage regulation purposes. The controller is designed based on injecting d-axis current pulses for short periods of time. These pulses have negligible losses which reduces the machine losses and increases the machine efficiency.