Application of interval computation technique to fixed speed wind energy conversion system

Any wind energy conversion system (WECS) experiences uncertainty in wind velocity, tip-speed ratio, power co-efficient and stiffness of the wind turbine shaft. Also, the magnetizing inductance of the induction generator varies during self-excitation process. This makes the analysis and control of WECS, a difficult proposition. This paper presents an interval analysis based computation method for the calculation and analysis of various machine parameters and variables in WECS. The usefulness of the proposed method in the design aspects of a WECS is discussed. The realistic (dependent) uncertainties in the equations are solved to analyze the behaviour of a self-excited induction generator under balanced operating conditions. Experimental results are included to highlight the behaviour of the induction generator voltage during transient phase.