Protection security assessment - An important task for system blackout prevention

Protection security assessment of power grids becomes an important task in the course of a competitive energy business and a decarbonized power generation. The analysis of past blackouts studied by the North American Electric reliability Council (NERC) shows that protection relays are involved in about 75% of all major disturbances. One reason for that is the non adequate adaption of the protection systems to the changing network conditions. In particular the relay hidden failures causes relay malfunctions and blackouts in the past. This paper is presenting a new automated method for blackout prevention. It analyzes and assesses the security of protection systems of networks as a whole. Routinely checks of contingency sequences are carried out and reveal bottlenecks of the protection behavior itself and of the coordination of network and protection. The numerical simulation tool PSS^®SINCAL is used providing the possibility of a holistic simulation of network and protection behavior on a fully automated manner. The handling of the big amount of resulting data is done by an intelligent visualization method like a “finger print” analysis.