Bipolar high voltage pulse generator without H-bridge based on cascade of positive and negative Marx generators

摘要

A parameterized bipolar high-voltage pulse generator without H-bridge based on cascade of positive and negative Marx generators is proposed. In the proposed circuit topology, the positive and negative Marx generators are connected directly without any auxiliary circuits. Each stage of the Marx generators consists of a diode, a storage capacitor, two MOSFETs switches. A 1 kV DC power supply is employed to charge the storage capacitors of the two kinds of Marx generators. The control signals of switches generated by FPGA circuit according to the setting parameters of high-voltage pulses and loads are sent to high-voltage pulse circuit via optical fiber. There are two remarkable features in the developed prototype: (1) the ability to adjust all of the parameters of the high-voltage pulse, especially the variable rising and falling time, (2) the better match properties to different loads. The key parameters of the developed bipolar high-voltage generator show as following: adjustable rising/falling time 50-500 ns, pulse width of top flat 0-1 ms, repetition rate 10 kHz (at +/- 15 kV and 200 pF), overshoot/undershoot less than 5%, and amplitude 0 to +/- 15 kV. The shape of waveform can be the rectangle and/or triangle. All the pulse parameters can be programmed arbitrarily.