A description of the estimation and control algorithms developed for our VAWT prototype will be included in the reference
[1] P. Bhatta, J. B. Mueller, and M. A. Paluszek, "Individual blade pitch and camber control for vertical axis wind turbines", Submitted to World Wind Energy Congress, 2008.
In this paper we present a dynamical systems model and control algorithms for a small, vertical axis wind turbine (VAWT). The wind turbine is designed for the domestic market, including regions without very favorable wind conditions. Good performance at low wind speeds is an important requirement for developing an economically viable, suburban VAWT. The performance of a VAWT can be greatly enhanced by incorporating estimation and control capabilities, along with advanced algorithms, such as model-based control algorithms presented in this paper. We consider a double multiple streamtube model as a basis for our dynamical system analysis and control synthesis. Individual blade pitch and camber controls are included in our VAWT design. Pitch control is achieved by rotating each individual blade about its vertical axis, while camber control is realized using a trailing edge flap on each blade. Using camber and pitch controls help in creating a greater force differential across the turbine than using pitch control alone. We present linear and nonlinear control laws for implementing pitch and camber control. A complete system simulation, which includes estimation of states and parameters, is also presented. State estimation is necessary to minimize system complexity by keeping the number of required sensors to a minimum, thereby reducing the cost. Parameter estimation will allow model-based control algorithms to work effectively in mass-produced VAWT. We consider an unscented Kalman filter for state and parameter estimation. We illustrate performance improvements of using individual blade pitch and camber controls. Finally, we discuss the development of Princeton Satellite Systems' VAWT prototype.