Analysis of high and low voltage grid failure propagation in large wind farms considering transformers, cables and VAR-compensators

This work presents an analysis of grid failure propagation in large wind farms. Stringent grid codes require the turbine for a certain voltage range to stay connected to the grid even during grid failures. These grid code requirements are defined for the point of common coupling (PCC) of the wind farm. Grid failures are propagated through the wind farm´s internal distribution system consisting of resistive, capacitive and inductive elements such as cables, transformers and compensation units like STATCOMs and capacitor banks. This paper presents three-phase models of a representative wind park distribution network. Simulation results of failure propagation in large wind park for different grid faults considering energy storage effects will be presented and discussed. Conclusions will be drawn by means of system specific parameters like cable length and rated power.