Responding to more demand in coming years, the task of the small wind energy industry requires progress on several fronts-the public policy initiatives, technology development, and market growth. One important issue of the wind energy utilization is the conversion efficiency of the usable energy into productive power. Enhanced technologies such as contrarotating blades, gearbox and lubrication, airfoils, generators, and power electronics will lower cost and increase energy production. The purpose of this paper is, therefore, to reinforce the effectiveness of employing contrarotating system to enhance the performance of a small wind energy converter (SWEC). With this concept, the SWEC works more efficiently and therefore produces more energy in a unit turbine area. To verify the SWEC performance, a research model has been built and tested over a range of operating conditions. Wind tunnel tests were carried out to ascertain the overall performance of the contrarotating SWEC. Results are presented for cases of different wind speeds and Reynolds number. The results demonstrated a significant increase in wind energy conversion efficiency and capability of operation at lower wind speeds while keeping up performance compared to a single-rotor system of the same type.

No abstract

No abstract

We are building an efficient and smart wind turbine system. The significant features of this turbine are its dual rotor blade system which is positioned horizontally at upwind and downwind locations, its drive train which is installed horizontally inside the tower with a new efficient induction generator, and its control and safety systems. The project focuses mainly on the methodology to analyze the power flow performance. The scientific literature indicates that a dual-rotor system could extract additional 20-30% power compared to a single rotor system from the same wind stream. Our wind tunnel test indicates that a scaled-down version of the dual-rotor turbine system may produce up to 60% more power than a single-rotor system. Designed for on-site power generation by commercial, industrial, and residential electric users in remote locations, our model uses wind tunnel effect to capture and amplify wind for optimized production of energy. It is intended that this turbine system will be available in tower-mounted design and can capture wind in regions where it has low speed wind. The successful design should allow an economical transition to a utility scale.

The purpose of this paper is to reinforce with theoretical and experimental evaluation the effectiveness of employing an induction generator to enhance the performance of a small wind energy converter (SWEC). With this generator, the SWEC works more efficiently and therefore can produce more energy in a unit turbine area. To verify the SWEC performance, a model has been proposed, simulated, built, and experimentally tested over a range of operating conditions. The results demonstrate a significant increase in output power with an induction generator that employs an auxiliary winding, which is only magnetically coupled to the stator main winding. It is also shown that the operating performance of the induction machine with the novel proposed technique is significantly enhanced in terms of suppressed signal distortion and harmonics, severity of resistive losses and overheating, power factor, and preventing high inrush current at starting.