Study on the Propagation Characteristics of Cascading Faults in Power Systems with Wind Farms

With the incorporation of large-scale renewable energies into the power systems, the electric power network’s operation characteristics show a new pattern. Renewable energy generation possesses strong stochastic, low immunity, weak support, low inertia response, etc., and the power systems will also inevitably experience N-1 and N-2 faults. These unexpected large disturbances bring serious challenges and are likely to lead to cascading faults and blackout events. This paper studies the propagation characteristics of cascading faults in power systems containing wind farms. The theoretical model of the cascading overload fault is built, and the fault ride-through (FRT) features and fault protection principle of wind farms are analyzed. Using MATLAB/Simulink, an IEEE 39-bus system model integrated with wind farms is created. The initial N-1 and N-2 faults are both imitated, and the fault evolution characteristics are obtained. It is concluded that the considerable power flow transfer will cause cascading overload fault, and the drastic voltage transients enforce the off-grid of wind farms, which may further deteriorate the cascading faults of the demonstrated system. Hence, the consistency between theoretical analysis and simulation results can be confirmed.