Wind energy is a cornerstone to the world of renewables. It is widely used in many parts of the world as a clean and effective form of power generation. However, wind power has a number of drawbacks, which limits its use in many regions. Solar power has been used not...
Brushless Doubly-Fed Machines have potential benefits in variable speed generation and adjustable speed drive applications by combining a robust machine structure with a reduced power converter rating. While recent work has demonstrated feasibility, steady-state performance has not been optimized. The nature of doubly-fed operation causes rotor currents of varying, relatively...
The Brushless Doubly-Fed Machine (BDFM) has recently become an
important research topic in the field of variable-speed AC drives. In
recent studies, the BDFM has shown significant potential for improving the
reliability and performance of AC drive systems, as well as reducing total
system cost. While the BDFM offers several...
With the increased attention on high efficiency and energy savings, power electronic
energy conversion equipment is increasingly incorporated in all levels of the power system.
The drawback of such equipment is the generation of nonsinusoidal currents in the power
distribution network due to the nonlinear operation. Harmonic currents may distort...
The distortions of input voltage and current waveforms generated by switch mode power supply (SMPS) operation are a major cause of concern in the power quality performance of commercial office buildings. These distortions are usually evaluated by performing a site survey of the building. In this thesis, a power quality...
Generation of electricity from the wind is becoming increasing popular as an
environmentally responsible resource. Current methods for generating electricity from
the wind involve the use of fixed-speed generators. However, the use of variable-speed
generators increases the amount of energy that can be extracted from the wind.
Most variable-speed technologies...
The purpose of this study was to determine the
effects of a six-week career planning dropout prevention
program on the self-concepts and academic achievement of
at-risk middle school students in an inner-city public
school environment. The research population consisted of
1,434 students (grades seven, eight and nine) attending an
With the introduction of high speed semiconductor power devices and the
increased application of adjustable speed drives (ASDs) for efficient speed control of ac
motors, there has been a growing number of costly motor-drive related process failures. It
has been found that the high dv/dt and high switching frequency have...
Power quality has become an important concern to both electric utilities and
end users due to the increased use of non-linear loads in modem power systems
over the past decade. Nonlinear loads inject harmonics into the power system and
thus may lead to poor power quality and lower power factor....
Advanced low power devices promote the development of micro power
generators (MPGs) to replace the batteries to power them. Due to the trend in
decreasing integrated circuit (IC) supply voltages, power supply designers are facing
more and more serious challenges. The objective of this research is to design a power...