Design of a novel controller for a small battery charging wind turbine.

Small battery charging wind turbines are used to provide electric power in locations where grid connection would not be feasible. However, existing controllers for such small wind turbines are often inefficient and unreliable. This work therefore examines the application of the little used Cuk converter to charge efficiently a battery bank from a 2kW permanent magnet generator. This circuit was chosen because the buck:boost action allows battery charging over a wide range of windspeeds, and neither the input or output currents are discontinuous. A controlled resistive dump load both safely loads the wind turbine when the batteiy bank is unable to accept all the power available from the generator, and also provides a low grade source of heat. A development of the basic circuit is to consider the use of self-regulating blades, which through safely limiting the maximum available generator power and controller input voltage, allows the significant simplification of the control electronics. The final stage of the work is the development of a PC-based simulator for rapidly evaluating the effect of different turbine designs or control strategies under a range of actual recorded wind conditions. A test bed is described on which a motor, controlled by the PC, mimics the effect of the wind turbine driving an actual small generator.