Loss of excitation protection method of rod-controlled power generator based on variable excitation current criterion

Demagnetization fault is a common type of synchronous generator fault, there are some malfunction problems in the current loss of excitation protection operating of the rod-controlled power generator, which needs further research. This paper firstly analyses the demagnetization process of the generator and the limitations of the existing loss of excitation protection scheme of the rod-controlled power supply. It proposes a protection improvement method with variable excitation current as the main criterion and generator terminal measured impedance and inverse reactive power as the auxiliary criterion. Secondly, simulation tests are used to verify the robustness of the proposed scheme under different fault scenarios. Then dynamic simulation experiments are carried out further to verify the engineering practicability of the proposed protection scheme. Finally, the main research work is summarised.