10.7kV nanosecond pulse generator based on pulse forming line and variable impedance transmission line transformer

Low-temperature atmospheric pressure plasma has important application value in the fields of material surface modification, waste gas and wastewater treatment, sterilization and disinfection. High voltage nanosecond pulse with rapid rise time can provide a higher constrained electric field, which could quickly ionize the gas and make the electrons quickly obtain higher kinetic energy. Higher density of free electrons and stronger chemically active substances will produce. Therefore, the high voltage nanosecond pulse generator is an efficient plasma excitation source with wide prospects. This paper proposes a 10. 7kV nanosecond pulse generator based on pulse forming line and variable impedance transmission line transformer(VITLT). The proposed pulse generator uses the inductance in the transmission line as the energy storage unit. The magnetic energy stored in the transmission line is released by MOSFET with a fast turn off speed to form nanosecond pulse. An interesting fact is that a variable impedance transmission line transformer is applied to multiply the output voltage of single module circuit. In addition, it can achieve modular pulse superposition through transmission line time isolation method to generate high voltage output. Finally, this paper carried out experimental research. The experiment results of single module circuit show that VITLT can achieve multiple increase of voltage amplitude. The output pulse amplitude of single module is 2kV, and the pulse width is 12 ns. A 7-stage multi-module stacker was built which can produce a high-voltage nanosecond pulse output with voltage amplitude of 10.7 kV, pulse width of 15 ns and repetition frequency of 200 kHz.