Finding Unstable Operating Points via One-Dimensional Manifolds

Renewable energy sources reinforce the energy supplied, but their sudden power changes can lead the system to unstable operating points. Therefore, finding the unstable points by varying the power injected into generation buses can help determine the robustness of a system with respect to the high penetration of renewable generation. In this paper, unstable solutions and bifurcation points of full QV and PV curves of one-dimensional manifolds are focused. The continuation power flow method is used to trace both curves. The simulations carried out in IEEE 14-bus system indicate that in the presence of generators injecting a large amount of active power, the system could become unstable without major disturbances since one may identify bifurcations and unstable solutions around the nominal voltage.