84. New Technique for Controlled frequency Supply from a Stand Alone Wind Turbine

This paper proposes a designed technique to generate controlled frequency supply from a standalone wind turbine. This technique is based on a controller by which the output power of the wind turbine is divided into two parts, the first part is considered to be constant power which is kept at a constant frequency, the second part has the remaining output power. These two parts are simultaneously generated by two induction generators connected to the same shaft driven by the wind turbine. The first induction generator geqerates the constant output power which feeds a critical load, while the second induction generator, which generates the remaining output power, is connected to a non-critical load through a threephase bridge converter. The non-critical load extracts any fluctuation of the output power of the wind turbine to keep constant shaft speed. The paper includes design of the three-phase bridge converter and the associated firing circuit, PID controller and the principle of the controlled system, as well as the performance and laboratory test results of the proposed technique.