Problem statement: Online out-of-stability assessment is a chanlenging computing problem. The out-of-stability can be assessed via online tracking for system variables as rotor angle. Approach: So, in this paper, a proposed algorithm for detecting the online out-of-stability is presented. The algorithm is based on real-time measurements via Phasor Measurement Units (PMUs), online Rotor Angle Detection (RAD) algorithm, and online Critical Clearing Angle (CCA) algorithm based on Adaptive Neuro Fuzzy Inference system (ANFIS). The algorithm is created to be implemented to detect the stability margin of the generators and the actual Critical Clearing Angle (CCA) then gives the adequate Remedial Actions (RAs) to trip the critical generators. The RAD algorithm is based on real-time PMUs measurements and direct equations to determine the rotor angle. Results: Due to the unavailability of PMUs, an off-line simulation is adopted to get the required PMUs measurements to be used in the proposed algorithm. Simulation results for Single Machine Infinite Bus (SMIB) under several testing cases are presented to show the effectiveness and validity of the proposed algorithm. Conclusion: the ADOS algorithm does not require any presetting tripping time or CCA so that it can be considered as an adaptive tripping algorithm because the algorithm needs only the SPMU measurements and only one generator data sheet parameter which is d. Thus, no need to any other presetting values algorithms like the blinder algorithm implemented in the conventional relays. |
