Background: For construction of free-electron laser(FEL) apparatus

we designed a high-power solid-state modulator system based on the module of insulated gate bipolar transistor(IGBT) switch.Purpose: To meet the higher performance requirements of linear accelerator microwave power source for the FEL.Methods: The module circuit of the high-power modulator is introduced

as well as the critical auxiliary circuit including protection circuit of IGBT

damping circuit

demagnetization circuit and compensating circuits.Results: The whole modulator system is simulated by using software and the module differences that may occurred.The modulator with inductive adder topology can generate a 130 kV

100 A and 13 MW pulse power.Conclusions: The results show that the inductive adder pulse modulator technology is feasible.