An interactive simulation of grid-connected DFIG units for protective relaying studies

Doubly-Fed Induction Generators (DFIG) are commonly utilized in wind farms nowadays due to their advantages as compared with single-fed ones. Control complexities and their unique characteristics may, however, raise different problems during abnormal or faulty operating conditions. In this paper, an integrated simulation for DFIGs in wind farms is presented for protection application purposes in particular. The developed simulation describes the dynamic behavior of the DFIG in an interactive manner incorporating the interaction of the machine unit, the control system, rotor protection circuitry and the utilized Current Limiting Fuses (CLFs) simultaneously. CLF is modeled by aggregating the fusing action with the power system simulation running employing the S-M function with level-2 M-file code in MATLAB-Simulink. The developed simulation enables effectively to explore the behavior of the aforementioned units when working together in the field. Different simulation examples are illustrated to emphasize the broad abilities of the developed simulation.