Eigenvalue-curve approach for fast assessment of rotor angle transient stability

Abstract

Abstract The phase-out of nuclear and coal-based electricity production and their replacement by power-electronics based renewable energy sources, especially in Germany, leads to more and faster power system dynamics. Anyway, not all European countries plan to abandon bulk power generation, so there will still be a mix of inverter-based sources and synchronous machines in the future, justifying the necessity of rotor angle stability analysis. This task grows with the number of assets. It requires to numerically solve a large set of ordinary differential equations which gets more and more challenging to do in real-time during contingency analysis in power system operation. Therefore, this paper introduces a new approach to quickly estimate the transient stability of rotor angles without the need of solving differential equations. It is based on a linearized system description, some assumptions on the rotor angle displacement and uses the fault location and duration as parameters. It is proven, that this approach can be used to reduce the number of contingencies which need to be analyzed in detail during system operation and therefore helps transmission system operators to keep the power system stable and secure.