Real-time testing of out-of-step protection devices

In future power systems the share of power electronic interfaced generation will increase and respective challenges related to power system protection will emerge. In this paper the performance of different out-of-step protection algorithms is assessed using actual relays from the network and real-time digital simulator RTDS. For the performance analysis various grid conditions were considered, e.g. system strength, line lengths and generation mix between renewables and conventional synchronous units. The results indicate that there are performance differences between the algorithms (relays), therefore, analysis considering the specific system characteristics should be made. Information obtained from this analysis is essential input for transmission system operators when planning their system operation and protection for future networks.