"PEGASE is a four year project dealing with the High and Extra High Voltage transmission and sub-transmission networks in Europe (designated as ETN) and implemented by a Consortium composed of 20 Partners including TSOs, expert companies and leading research centre’s in power system analysis and applied mathematics. Its overall objectives are to define the most appropriate state estimation, optimization and simulation frameworks, their performance and dataflow requirements to achieve an integrated security analysis and control of the ETN. The heart of the PEGASE project will involve advanced algorithmic, build prototypes of software and demonstrate the feasibility of real-time state estimation (SE), multi purpose constrained optimization (OPF) and time domain simulation of very large model representative of the ETN, taking into account its operation by multiple TSOs. Project R&D ambitions: The first ambition is to relieve all knowledge barriers to provide all TSOs with a synchronous display of the state of the ETN, very close to real time (typically each 5-10 seconds). The second ambition is to develop OPF programs determining realistic system operating points that include TSO operating rules but also optimal preventive or corrective actions, typically for real-time congestion management. The third ambition is to improve the existing state of the art technology in time simulation of very large system to permit: i/ off-line studies of the ETN including possibly interconnections with neighboring systems (i.e. Russia), ii/ dispatcher training simulation iii/ preventive security assessment and in on-line emergency conditions, faster than real-time simulation opening new perspectives for an anticipative control of the system. Project expected impacts: The availability of duly tested prototypes will allow for a quick implementation of the developed tools in a central facility and in existing computing environments. A better management of crisis will allow decreasing conservative security margins and improving the identification of real risks. Operating with higher power flows and closer to real available transfer capacities determined more transparently from the shared real-time model will enhance the cross-border electricity market. Eventually, the first European dispatcher training simulator will be at arm length for use in a European training center allowing the simultaneous training of dispatchers from several countries that is the cornerstone of the integrated operation of the ETN."