Analysis and simulation of an optimally operated DOIG based stand alone VSCF generation system under converter current and machine speed constraints

In the context of supplementing energy requirement for remote localities far from the reach of the national grid and having good wind energy potential, installation of modular wind plants operating in the stand-alone mode is the desirable choice. The optimal operation of such isolated generating system is essential so as to increase the overall efficiency and hence reduce the cost of energy generation. Reducing losses also helps to reduce the maintenance needs and increase the longevity of the generating system. Many works relating to the analysis, design and performance optimization of grid connected DOIG based VSCF generation system has been reported in literatures. However, surprisingly little attention has been focused on optimal operation of stand alone DOIG based VSCF generation system. In this paper an optimal operational strategy has been developed for a DIOG based VSCF generation system supplying an isolated load. The constrained optimization problem is solved in the MATLAB environment using the Lagrange multiplier technique. The control algorithm makes the generating system to operate at min. machine loss trajectory while the wind speed, active load power and load power factor angle varies with in their specified range. The theoretical prediction is supported by simulation using MATLAB SIMULINK