Dual Marx circuit and pulse transformer based Cascade type solid state modulator development

In recent years, pulsed power technology has continued to develop in depth, and its application areas have gradually expanded from military fields such as particle accelerator to civilian fields for instance biomedicine, plasma science, and food industry. As its application scenarios continue to expand, the pulse voltage parameters and other needs continue to improve. In order to investigate the mechanism of aging and failure of insulation materials under special working conditions in the power industry. This paper puts forwards a solid state modulator based on dual Marx-type main circuit topology and step-up pulse transformer cascade. It is consisted of an all solid state bipolar Marx pulse generator using IGBT as switches to generate primary voltage pulse. The IGBT driver circuit uses the magnetic core to transfer the control signal, which adopts core stacking and inverse paralleled secondary side winding. It only needs two drive signals to realize the different control of four types of switches in the main circuit. The drive circuit has a simple and reliable structure, ensuring the synchronization of switches. The maximum output voltage of the pulse generator is 0~±5 kV with a pulse width of 3–10 μs and an adjustable repetition frequency of 0–100Hz. The output of the pulse generator is stepped up by pulse transformer. Based on the bipolar Marx pulse generator and pulse transformer, a solid state modulator was built and prototype test is carried out. The experimental results show that the output voltage of the solid-state modulator is 0~±160 kV, the pulse width ranges from 3 to 10 μs, and the maximum output current is 10 A at 1 Hz rated output frequency. The output voltage, pulse width, and terminal between the positive and negative pulse can be adjusted flexibly. The solid-state modulator developed in this paper provides a good technical support to further explore the insulation failure mechanism of bipolar high voltage pulses.