الفهرس 
Title : Iron saturation implementation of brushless doubly fed reluctance generator driven wind turbine
SummaryOnly 14 pages are availabe for public view
 |  | from | 137 |  |  |
| | | from | 137 | | |
Abstract
The generation of wind energy has increased in recent decades as a clean, cheap, and renewable energy source; wind energy would share a fair amount of energy in the global energy production. The wind turbine generators play a vital role in the whole electric generation system. Therefore, any sudden faults in the generator will interrupt the process of power generation. The Brushless doubly fed reluctance generator (BDFRG) provides a good alternative for the doubly fed induction generator (DFIG) for wind energy applications due to the absence of the slip rings and brushes. BDFRG can meet the energy generation grid code requirements by adjusting the active and reactive power.
In literature, it was noted that, the machine saturation is not included in the machine modeling. Real-time modelling of the BDFRG is a challenge due to the high leakage inductance of the stator windings. Since magnetic saturation of the iron parts affects the inductance values, therefore analyzing the effect of magnetic saturation on the BDFRG performance is important.
In this thesis, a complete d-q mathematical model of the BDFRG driven by a wind turbine is presented to simulate the whole system. A Simulink\MATALB model is developed to model the BDFRG wind turbine system. The Simulink model is verified to track the maximum power from wind at different wind speeds and control the generator reactive power. A finite element (FE) model using FEMM software is developed, to generate the relationship between the generator currents and the inductance values. The FE model is linked with a MATLAB m-file to run the FE model at different values of current and hence calculate the machine inductance. The generated data is recorded in a lookup table. Therefore, a complete model of BDFRG including iron saturation is developed. The complete model will be studied to show the effect of saturation on the generator performance during achieving the grid code requirements under normal operation.
Based on the proposed lookup table, Simulink models of a 1kW BDFRG driven by wind turbine, with two cases of constant and variable inductances, are developed and verified with FE analyses at a range of wind speeds above and below the synchronous speed. Field oriented control technique is used to decouple the generator active and reactive power control, moreover, maximizing the active power extracted from the wind turbine and adjusting the generator power factor. The lookup table proposed is verified using finite element analysis at different modes of operation of wind speed and compared with the constant inductance model. The iron non-linearities are successfully implemented in modelling the BDFRG wind turbine system and investigated using FE analyses.
Finally, a BDFRG prototype is built and experimentally verified with the FE analysis to validate the basic concepts of the BDFRG.