Integral-based stabilization of generator differential protection

This paper presents a new approach to stabilization of generator differential protection with use of the integral principle. An additional relay stabilization is needed especially for the cases of close external faults with CT saturation, energization of the near-by transformers or start-up of supplied motors. Most of contemporary produced generator protection devices do not employ any stabilization or may use the second harmonic restraint that is well known from transformer protection. The proposed here integral principle is simple and exhibits superior performance against other commonly applied algorithms. The theoretical investigations are followed by testing with simulation runs as well as recorded signals.