文摘
This paper proposes a variable speed control algorithm for a grid connected doubly-fed induction generator system. The main objective is to track the maximum power point by using an adaptive hill climb searching (HCS) technique based on fuzzy logic controller (FLC), and compare it with the conventional optimal torque control method for large inertia wind turbines. The role of the FLC is to adapt the step-size of the HCS method according to the operating point. The control system has two sub-systems for the rotor side and the grid side converters (RSC, GSC). Active and reactive power control of the back-to-back converters has been achieved indirectly by controlling q-axis and d-axis current components. The main function of the RSC controllers is to track the maximum power through controlling the rotational speed of the wind turbine. The GSC controls the DC-link voltage, and guarantees unity power factor between the GSC and the grid regardless of the magnitude and direction of the slip power. The proposed system is developed and tested in MATLAB/SimPowerSystem environment.