Robust control of a wind conversion system based on a hybrid excitation synchronous generator: A comparison between H_∞ and CRONE controllers

摘要

This paper deals with a Wind Conversion System (WCS) based on a Hybrid Excitation Synchronous Generator (HESG) connected to an isolated load. The set is modeled under Matlab-Simulink. To ensure an efficient and reliable use of the system, a tight control remains vital. In fact, the dynamic equations of a turbine are strongly nonlinear as are the ones of a HESG; most of the system parameters are highly uncertain, and, at last, a WCS is always affected by disturbance sources such as load variances, harmonics, mechanical vibrations... To address these problems, robust control methods must be adopted. In this paper, two strategies for the control of variable speed wind turbine are investigated. First, an H-infinity controller is implemented. Then, a second-generation CRONE controller is designed. The performance of the two regulators is compared with respect to the tracking of the optimal rotation speed, the attenuation of the mechanical vibration and the robustness to the uncertainty of the parameters, using time-domain simulations. It has been found that the CRONE controller is more robust to parameters uncertainty and minimizes the fluctuations of the torsional torque and the generator's angular velocity. Finally, an experimental validation of the velocity controllers is presented to complete the simulation results and fully validate the chosen approach. (C) 2018 International Association for Mathematics and Computers in Simulation (IMACS). Published by Elsevier B.V. All rights reserved.