Comparative analysis of MPPT techniques and Optimal Control for a PMSG-based WECS

Abstract

This paper presents a comparative study about different
schemes for maximum power point tracking for Wind Energy
Conversion Systems (WECS) based on Permanent Magnet
Synchronous Generator (PMSG). Owing to the inherent changing
nature of the wind, it is required to have techniques capable of
fulfill the task of extracting the maximum available power at
any time by tracking some system variables such as rotor speed,
torque, power among others. Therefore, including a controller
that can track the maximum power point in any wind speed
scenario is essential. This paper analyzes four MPPT techniques,
Power Signal Feedback (PSF), Tip Speed Ratio (TSR) control,
Perturb and Observe Method (P&O) and Optimal Torque (OT)
control using a wind speed estimator for the schemes that require
such measurement. A comparison of the performance of these
MPPT algorithms has been made under a varying wind speed
scenario to examine its characteristics such as efficiency and ease
of implementation. A nonlinear optimal control scheme based on
a State Dependent Coefficient Factorization (SDCF) was designed
to track the trajectories generated by the MPPT algorithms.
Simulations results developed in Simulink are presented to show
the characteristics and performance of each technique.