Simulation and Analysis on the Influence of Under Excitation Limiter for Control Strategies of HVDC Sending Grid

At present, because the accuracy of the model and its parameters of Under Excitation Limiter (UEL) for generators in power system stability simulation in China is insufficient, power factor depth of the generators during the simulation evidently is different from the capability of generators, the check of steady voltage rise will be optimistic and the pre-control strategies based on these results are inaccurate. In this paper, at first the model of under excitation limiter based on the mainstream automatic excitation regulator is established; then the impacts of the model on steady voltage rise and pre-strategies of Tianzhong HVDC sending grid are analyzed by simulation, which point out that the check of serious faults in power system stability simulation should consider the UEL; finally the setting method of UEL curve for improving the capability of power factor depth is proposed, which have been applied on the generators near the Tianzhong HVDC sending grid, the availability of this method is verified.