Influence of Overexcitation Configuration on System Operation Risk of Tianzhong DC Thermal Power Unit

In view of the possible inconsistency between the excitation current value used in the configuration of overexcitation limit and rotor overload protection in the actual system and the excitation current definition in the rotor overcurrent curve in the national standard, the relationship between the excitation AC current and the excitation system DC excitation current was obtained by solving the equation of the rotor control link according to the mathematical model of the rectifier of the excitation system of the unit. Finally, the simulation was carried out for the theoretical part, and the influence of fault types on the action time of the overexcitation limit was compared and analyzed. The final conclusion has guiding significance for the coordination and configuration of overexcitation limit and rotor overload protection in practice.