A NOVEL DIRECT DRIVE SENSORLESS MPPT CONTROLLER FOR

Abstract

Wind is the safest and most abundant renewable source of energy in nature. With ever increasing
concern on environmental pollution and energy crisis, generation of power from wind developing very fast .In the
Wind Energy Conversion System (WECS) the variable speed wind turbine, Permanent Magnet Generator (PMG), ZSource
Inverter (ZSI), Sensorless Maximum Power Point Tracking (MPPT) controller is proposed. Though the
conventional type induction generator has the advantage of robust construction and maintenance free operation it
has drawbacks like low power factor and need for an ac excitation source which is overcome by the PMG. To obtain
the fixed voltage and frequency PMG generated voltage is feed to power converters. Conventionally three stages of
power conversion consist of rectifier, boost chopper and PWM inverter reduces the efficiency, power quality and
reliability of the overall WECS. To overcome these barriers of conventional system the two stage ZSI based
sensorless MPPT controller based WECS is proposed. The ZSI employs a unique impedance network can buck and
boost the input voltage and increases the efficiency of the power conversion system. The maximum power point for
each speed is traced using sensorless MPPT controller which estimates the rotor speed, by using Zero crossing
detector. The proposed sensorless MPPT controller for direct drive WECS along with the Z-Source inverter is
simulated in MATLAB/SIMULINK.