  This paper presents a sensor-less maximum power tracking (MPT) pitch
controller for grid connected Wind Turbine (WT). The main advantage of the
proposed architecture is that the approach ensures smooth operation and thus
minimizes the mechanical stress and damage on the WT during high wind speed and
grid transient conditions. Simultaneously, it also: a) reduces transients in
Point of Common Coupling (PCC) bus voltage, b) reduces rotor speed
oscillations, and c) controls the output power of the wind turbine without
exceeding its thermal limits. The approach can work without wind speed
measurements. In order to consider the effect of grid variations at the PCC,
the affected area in the grid is modeled as a study area (area of interest),
and remaining area (external area) is modeled as frequency dependent reduced
order model (FDROM). The reduced order model (ROM) is then used to estimate the
reference speed. The proposed controller is designed using the error between
actual speed of the generator and the reference speed, to ensure smooth
operation and limit the speed and aerodynamic power at the rated values. The
architecture is evaluated using wind farm integrated Kundur's two-area and
IEEE-39 bus test systems using real-time digital simulator (RTDS).
