A simplified modeling method of new energy sources applied in relay protection

Nowadays, new energy has been massively accessed to the distribution network. Since its complex topological structure and control characteristics increase the complexity of the new energy source model, it is necessary to study the simplified modeling of new energy sources for the relay protection simulation analysis. Utilizing the modeling idea of testing and analysis and the simplified modeling method based on experimental data, the author treats the generation unit with complex architecture and control information as a black-box model in this paper. The fault current expression is depicted by means of the typical control system response; meanwhile, the relationship between the fault current expression and the fault voltage amplitude is created with sample data of the voltage drop test, the nonlinear mapping relationship between fault current and fault voltage is obtained, thus the new energy source model can be equivalent to a voltage controlled current source. Taking the Doubly Fed Induction Generators (DFIGs) as the modeling object and using fine modeling to simulate the transient fault under symmetrical short circuit conditions, the author establishes a simplified model with the consequential sample data.