This paper presents an out-of-step protection algorithm based on angle derivatives, which makes use of wide-area measurements and can be applied on arbitrary tie-lines in electrical power systems. The developed algorithm uses PMU measurements that are taken at both ends of a transmission line. Based on the changes of the electrical quantities in the power system, the algorithm detects unstable system conditions. Thus, the developed solution is settingless and can be easily applied where an out-of-step condition is expected. The concept is deployed by using an industrial controller and tested by conducting numerous hardware-in-the-loop simulations. Additionally, recorded data from actual out-of-step events in the Icelandic power system are used to validate the developed algorithm. The performance of the implemented method is compared against the traditional impedance-based out-of-step protection methods. The results confirm that the proposed algorithm detects out-of-step conditions more reliably and faster than the traditional impedance-based solutions.@en

This paper presents a robust and adaptive out-of-step (OOS) protection algorithm, using wide-area information, that can be applied on tie-lines in observable power systems. The developed algorithm is based upon real-time computation of the system impedance and makes use of the well-known power-angle characteristic. In this way, a setting-less OOS concept in real-time environment is developed, which is applicable for tie-lines in an arbitrary power system. Furthermore, the developed protection algorithm is installed on hardware and is verified by numerous tests. The performance of the new hardware implementation is compared to the traditional impedance-based OOS protection methods. The results confirm that the proposed algorithm detects OOS conditions faster and more reliably than the traditional impedance-based solutions.@en