Indian Journal of Science and Technology

Abstract

Objectives: A new cheap wind-driven grid-connected cage induction generator has been used to generate electrical power. The performance of the generator has been ameliorated through multiple change of its number of poles using pole amplitude modulation to comply with the wind speed. The generator stator voltage has been adjusted via voltage controller for better performance. Methodology: Circuit and mathematical models have been developed to represent the generator system. An algorithm has been developed and implemented through computer programs to determine the performance characteristics of the turbine-generator system. The performance has been judged by comparing it by the performance when feeding the generator through a rectifier-inverter set in the stator side, which is costly but leads to a generator with ideal performance. Findings: Complete performance characteristics of the new proposed system have been computed. The obtained results have been used to establish a control protocol to guarantee maximizing the output electrical power. The suggested method has been with those of the case of using a rectifier-inverter set in the stator side to achieve ideal operation of the generator. The comparison has proved that the suggested method, being cheap, is very efficient as the proposed technique led to driving the generator and consequently the wind-turbine at speeds close or equal to those realizing the maximizing tip-speed ratio, which results in extracting the greatest mechanical energy from the wind. The output power applying the presented method closely approaches the output power of the generator when ideally controlled by the aid of a rectifier-inverter set inserted in the stator side. Applications: The very good performance obtained with the suggested control technique besides its low cost encourages its application in case of small and moderate size wind-driven grid-connected induction generator systems.

Keywords: Induction Generator, Pole Amplitude Modulation, Wind Energy