Effect of wind speed and load power factor variation on optimal sizing of the machine and converters for double output induction generator based stand-alone wind energy conversion systems

Abstract

In this paper, an algorithm for finding out the optimal ratings of the machine and power electronic converters of a wind turbine driven stand-alone double output induction generator based variable speed constant frequency generation system is reported, which seeks to minimize the cost of energy generation. The nonlinear constrained optimization technique employed includes, among others, the reactive power balance constraints, which are not often considered for stand-alone systems. For this purpose, the load power factor is modeled as a random variable with known probability density function. The total energy captured is calculated for a given wind velocity density function and load power factor density function. The proposed method finally finds the optimum combination of machine and converter ratings, which results in minimum cost of energy. The effects of changes in load power factor and wind velocity distribution are also discussed in detail.