Self-shunt excitation systems are widely used in large synchronous generators. Based on an in-depth study of field flashing of large synchronous generators

and according to the characteristics and requirements of field flashing

this paper proposes a new method of designing the main circuit of the field flashing system based on the time constant of field flashing and rotor winding

including the scheme of power supply selection and rectification

the selection and calculation method of the time constant of field flashing and rotor winding

and the key device design method. A series of new control strategies for the large synchronous generators are presented

including the coordinated control strategy between the field flashing system and the rectifier

the safety exit strategy

and the step-up process control strategy based on the integral separation method. The effectiveness of the proposed design method and control strategy is fully verified by simulation results and project practice of 1 000 MW turbo-generators and 700 MW hydro-generators.