Renewable Energy, Vol.93, 188-200, 2016
An improved reduced-order model of an electric pitch drive system for wind turbine control system design and simulation
To obtain satisfactory dynamic characteristics and enhance numerical simulation efficiency, an improved reduced-order transfer-function model of an electric pitch drive system (EPDS) for a wind turbine is proposed. First, a detailed transfer-function model of an EPDS is developed on the basis of its mathematical model. Thereafter, the improved reduced-order transfer-function model for an EPDS is derived from the detailed model by transfer-function approximation, sensitivity analysis, and block diagram reduction. The frequency-domain characteristics of the proposed model and their effects on the stability of the pitch angle control system are also analyzed and compared with that of a first-order transfer function model. Finally, the dynamic characteristics of an EDPS using the improved model are analyzed and verified by a practical EPDS test platform. Furthermore, based on the FAST-MATLAB/Simulink co-simulation tool, simulation comparisons are performed on the loading characteristics of a wind turbine to further validate its availability in it. Results show that the improved model is superior to the first order model for the performance analysis of a wind turbine pitch angle controller, and it also can meet the requirements of large-scale loading simulations for wind turbines both in terms of the precision and the time efficiency. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords:Electric pitch drive system;Loading simulations;Pitch angle controller design;Reduced-order model;Wind turbines