Enhancing the Performance of Wind-driven Cage Induction-Generators through changing the number of poles

Abstract

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. Circuit and mathematical models have been developed to represent the generator system. The performance characteristics have been computed using algorithms implemented through computer programs. Complete performance characteristics of the new suggested system have been computed. The results led to control protocol to achieve optimum performance. A real case of wind profile has been studied, and the results have been compared with those obtained from the case of a fixed-speed, fixed number of poles induction generator and the case when using a back-to-back voltage source converter set in the stator side to achieve ideal maximum wind-power point tracking. The comparison has proved that the suggested method, although 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 satisfying the optimum tip-speed ratio, which leads to extracting the maximum mechanical power from the wind. The output electrical power employing the suggested method is very close to the output power of the generator when employing ideal tracking of the maximum power point by adjusting the stator frequency through the use of back-toback voltage source converter set in the stator side