Sensorless maximum power point tracking in dual power flow wind energy conversion system

Abstract

This paper proposes a sensorless maximum power point tracking (MPPT) strategy for dual power flow wind energy conversion system (WECS) based on electrical variable transmission (EVT). The outer rotor torque of the EVT is suitably controlled according to the outer rotor speed to realize the MPPT without the knowledge of wind velocity. Moreover, the model reference adaptive system (MRAS) observers are adopted to observe the outer rotor speed and position. Therefore, the proposed wind energy conversion system is controlled without physical sensors such as wind speed sensor and position sensor. Both the normal and the simplified MRAS observers are analyzed and the performance of each observer is compared. The simulation models are built based on Matlab/Simulink, and the simulation results validate the feasibility and effectiveness of the sensorless MPPT control of the proposed system.