Abstract
The objective of this paper is to estimate the risk of experiencing stability loss at a voltage-controlled bus bar of an electrical power grid. Methods used for estimating and predicting imminent stability losses are presented together with underlying concepts. The approach is based on observing the current power flow at the node of the observed grid. The method uses no a priori knowledge of specific metadata nor does it need detailed models. A voltage control is not required; however, this does not restrict the applicability of the current method, provided the reactive power used for control is included in the observed load flow at the node under observation. Findings from both numerical simulations and experiments in a real power system are presented. For the experimental environment, the test facility for energy systems and wind power plants at the Jade University in Wilhelmshaven has been used. This environment offers the possibility of investigations in reproducible scenarios for energy systems. Here it is possible and also permissible to provoke system states which, in the field, is feasible only in extremely exceptional cases, if at all. So, in the first step evidence for an impending collapse due to stability loss is identified and subsequently the collapse is observed.