Modelling and simulation of WECS for maximum power extration and optimal efficincy control using squirrel cage induction generator

Abstract

The paper describes the development of an algorithm for maximum power extraction with a strategy for optimal efficiency of wind energy conversion system (WECS). The proposed control strategy attempts a dual purpose of maximum power extraction from the wind turbine and an optimal efficiency of the induction generator. This combination of the controller strategy results in increasing the overall efficiency. Here the configuration helps to exploit the low wind speed region, with the system comprising of HAWT and SCIG. A maximum power extraction (MPE) controller is used to extract the maximum wind turbine output power and Loss Minimization (LM) controller is introduced to minimize the generator electric loss. The input to both optimal controllers is the differential speed available due to the gears at generator unit. The switching scheme used is space vector modulation devoid of the wind speed measurement, unlike its dependence in other algorithms. The controllers determine the optimal d-axis and q-axis stator current components of the induction generator through optimal conditions and, thus fast dynamic response of the WECS is achieved. The entire proposed system is modeled and simulated using power system Simulink blocks in MATLAB R2013a to obtain the desired results. The studies have been carried out to confirm the effectiveness and the operational improvements. This system of dual controller can be implemented in a real world WECS system.