Design Of Variable Pitch Control System For Vertical Shaft Wind Turbine Generator

With the rapid economic boom and accompanying over-usage of non-renewable energy sources such as coal, oil and gas, environmental energy issues have never received more attention, which in turn propelled research and development of renewable energies. Amongst all of the new energy sources, wind power has entered people’s lives, with its most prominent form being power generation. The technology of horizontal axis wind turbine has stabilized in recent years, effectively driving down the generation cost. Unfortunately, many short-comings were also exposed, such as its unstable center of gravity, and the necessity of yawing device Noise is a concern as well, which deems this technology unsuitable for urban implementations. Moreover, the fact that leaf blades are not affected by alternating gravity stress has reduced machines’ service lives. In order to conquer all the aforementioned issues effectively, vertical axis wind turbine has entered the scene, drawing more and more attention in the academia. Nevertheless, vertical axis wind turbine faces its own issues. In particular, its inability to auto start and inefficient usage of wind power have hampered this technology’s development.This paper intends to explore the possibility of implementing a micro H-shape vertical axis wind turbine with pitch regulated control. First, we attempted to create a mathematical model of turbine’s operation. Based on theoretical force analysis on each circumferential locations of turbine leafs, we established an understanding of the optimal pitch angle while the turbine is in startup and operation stages. In terms of turbine’s hardware design, we implemented a combination of worm-and-gear decelerators and stepping motors as leafs’ independent variable-pitch system. Together with decelerators’ self-locking ability and steppers’ unique operational method, we were able to grasp a finer control of the pitch angles. In the end, through implementations in Matlab and construction of a micro H-shaped verital axis turbine, we were able to demonstrate the validity of variable pitch theory using both simulations and experimental data.