Research On Negative And High Voltage Ultrafast Pulse Generator Based On High Power MOSFET

Pulsed power technology is an important technical foundation for defense science and technology and high-tech research.It is widely used in many fields,such as pulse radar,pulsed-dilation framing camera,inertial confinement fusion,and so on.At present,pulse power technology is developing in the direction of high voltage amplitude,large current peak,narrow pulse width,high repetition frequency,and small volume.The Marx generator is a device that generates high-power pulses,has a high voltage output amplitude,and has a simple design structure,and is therefore increasingly used in the development of pulse power technology applications.Power MOSFETs have features such as fast switching speed,high repetition frequency,good thermal stability,small size,and long life.They are often used as switching devices for Marx generators.Due to the limited maximum drain-to-source voltage allowed for a single power MOSFET,a pulse generator developed using a single power MOSFET cannot meet the requirement to generate several thousand volts of high-voltage pulses.Although the pulse voltage output by the ultra-fast high-voltage pulse generator developed using the principle of magnetic induction superposition can reach thousands of volts or even tens of thousands,the volume of the pulse generator is huge.In this paper,a series voltage divider structure combined with Marx circuit structure is used to develop the pulse generator.Not only does the pulse output amplitude meet the requirements,but also the volume is greatly reduced.This paper mainly focused on the following work on negative high-voltage ultra-fast pulse generators.1)By comparing the advantages and disadvantages of several combinations of modulation switches,the series voltage divider structure combined with Marx circuit structure was determined as the experimental scheme of this paper.2)The transmission characteristics of the high-speed pulse,the voltage divider structure of the power MOSFET in series and the structure of the Marx generator,and the working principle of the clipper are analyzed.3)Simulation software OrCAD PSpice 16.3 was used to simulate the primary,secondary,and six Marx high-voltage pulse generators and the clipper respectively.The six-stage Marx high-voltage pulse generator obtained output pulses with a voltage amplitude of-8.7 kV,a leading edge time of 10.8 ns,and a pulse width of 105 ns,verifying the analysis results for them.4)Under the conditions of different DC voltage,output capacitance and output resistance,the output of the primary and secondary Marx high-voltage pulse generators was measured,and the rules affecting the output of the pulse generator were summarized.On this basis,a six-stage Marx high-voltage pulse generator was commissioned and developed.A six-stage Marx high-voltage pulse generator with an applied DC voltage of 1.6 kV,an output capacitance of 22 nF,and an output resistance of 500 ? can obtain a voltage amplitude of-6.84 kV at the output of a six-stage Marx high-voltage pulse generator.A negative high voltage pulse of 9.2ns.