Refined modeling and real-time simulation of grid-connected DFIG

This paper proposes a refined real-time co-simulation platform for Wind Energy Conversion System (WECS). The proposed detailed simulation model considers the aerodynamic, mechanical dynamic, and electromagnetic transients of individual DFIG and electromechanical transients of the power grid. The rotor kinematics equation is used as the interface between the mechanical and electromagnetic models. The Frequency Dependent Network Equivalent (FDNE) method is used to implement the hybrid simulation of electromagnetic and electromechanical transients. The real-time co-simulation platform is built through the combination of FAST developed by NREL, RT-Lab, and PowerFactory. To perform the real-time data interaction between FAST, RT-Lab, and PowerFactory, the communication module is developed based on UDP in this paper. Compared with the existing simulation tools, the proposed co-simulation platform highly enhances the simulation accuracy of WECS. Besides that, the simulation efficiency is also highly improved. The proposed simulation platform can be used for the studies of coupling dynamic analysis, grid-connected dynamic analysis, and hardware-in-the-loop simulation. The DFIG and IEEE 39-bus power grid are used as the case. The case study was conducted and analyzed, proving the correctness and accuracy of the co-simulation platform. Meanwhile, the simulation speed is fast enough for real-time simulation.