Coordinated out-of-step protection system based on WAMS

This paper describes a novel coordinated out-of-step protection system. The purpose of the protection system is to prevent total system collapse caused by step-out in large-scaled interconnected power grid. Different from traditional out-of-step protection which is based on local power grid information, this system is based on wide area measurement system, the protection system can observe power systems more comprehensively, the protection principle can detect out of step in main transmission interfaces in the power grid, so it can improve the coordination and selection of liquidating out of step fault in large power grid. The paper provides the principle and characteristics of the protection