Out‐of‐step protection of synchronous generators based on a digital phase comparison in the time domain

The study presents a new out‐of‐step algorithm used for the protection of synchronous generators. The algorithm is implemented on the principle of a digital phase comparison in the time domain. Phase voltages and currents measured at the generator bus bars are used as input signals. On the basis of the measured phase voltages and currents and known generator parameters, the internal voltages of the generator in the time domain are calculated. The algorithm compares the phase and internal voltages of synchronous generator and on the basis of the out‐of‐step index it detects a disturbance. Model of the test network is implemented in MATLAB/Simulink software package. The algorithm was tested on turbo and hydro‐generator models. The proposed algorithm test results were compared with a conventional method based on measurement of the impedance. The obtained results show good properties of the proposed algorithm.