Variable Electromotive-force Generators for Wind Turbines and Hybrid Vehicles, and Wind Tower Technology for Power Generation

In this dissertation, variable electromotive-force generators, and Wind Tower technology are developed as alternatives to current technologies in power generation and transportation system. Theoretical, experimental, and numerical studies of the generated electromotive force in the modified generator show the reduced torque loss of the generator and an increased rotational speed of the generator rotor by adjusting the overlap between the rotor and the stator. A simple and robust active control system is developed to adjust the overlap between the rotor and stator automatically and provide a stable output power that has less than 3% variations around its average values. This concept can improve the fuel efficiency of hybrid vehicles and increase the efficiency and expand the operational range of wind turbines. A novel multiple generator drivetrain configuration is developed at which a single-generator in a large wind turbine is replaced by multiple generators with the same or different rated powers. An electromagnetic clutch mechanism is employed to run the generators independently or together; this provides higher reliability and reduces scheduled maintenance and power loss especially at low input powers. A novel prototype is designed and fabricated; the system worked smoothly and the results show the possibility of running generators independently and together based on the input speed, using the electromagnetic clutch mechanism. A precise and accurate model for calculating the power and energy densities from measured wind speed data at an arbitrary site is developed to evaluate the potential of generating electricity using the wind power. In this regard, a novel ducted turbine, referred to as the Wind Tower technology, for capturing wind power and generating electricity in either residential or commercial scale applications is studied theoretically, experimentally and numerically. There is a good agreement between the estimated output power values from theoretical and experimental data. Also, the numerical simulation of the fluid flow inside the tower has provided an optimum dimension range of the Wind Tower components. The economic evaluation for designing and manufacturing a Wind Tower shows the potential of having cost reductions and a quick return on investment in areas with higher electricity rates