A circuit model of an electro-magnetic pulse(EMP)simulator driver with 2.5 MV rated voltage and fast rise time is established by the circuit simulation software and the measured output waveforms of the generator. An equivalent flash circuit is set up for the weaker insulation positions in the simulator

such as the output terminal of Marx

intermediate transfer switch

peaking capacitor

and intermediate capacitor. The modified model is used to analyze fault states of the driver

and the simulation results coincide well with the experimental data in debugging stage. The fault simulation and analysis combined with the physical phenomena - violent noise or breakdown of power supply appearing in the experiments and the subsequent output voltage reduction

can accurately locate the flash faults of the EMP simulator.