Smoothing electric power production with DFIG-based wind energy conversion technology by employing hybrid controller model
Belachew Desalegn, Desta Gebeyehu, Bimrew Tamrat
Abstract
The operations of WPTSs needs to be regulated under both its linear and nonlinear operating behaviors in order to ensure the maximum possible wind power production with lowering costs. This involves developing robust control structures that can stringently handle WPTSs’ sophisticated operation. In efforts to achieve this objective, the previous studies proposed various control strategies that were widely employed for the adjustments of WPTSs’ mechanical components. Herein, this paper pursues a rarely studied electrical-component control approach by implementing IFOC-based MPPT strategy on a RSC of DFIG-based WPTS. The ultimate goal of this study is to maintain the electric power quality by regulating the signal THDs of the system’s rotor alternating current along with mitigating the switching transients. To this end, the performances of conventional PI, and FL-tuned PI (FLPI) controllers, under the system’s both normal voltage rating & low voltage operation—it was assumed to be 10% of normal voltage rating, are set to be evaluated. Furthermore, the overall simulation of a 2 MW power scaled-DFIG system comprising aerodynamic model, electrical system model, control system model, and the controller models was implemented in MATLAB-SIMULINK environment in testing the effectiveness of the proposed approach based on a rated wind speed of 10 m/s. Accordingly, the THD factors of rotor alternating current are resulted to be 9.15% with PI & 8.61% with FLPI under normal voltage operation, and 35.46% with PI & 23.25% with FLPI under low voltage operation. With the recommended baseline of 75%, the FLPI model performance accuracy for the current THD control is found to be 76.75% along with mitigated switching transients, while that of PI is 64.54% without mitigated switching transients in the case of nonlinear operating behavior. Hence, FLPI model has proven to show a superior overall performance.