A Bipolar Pulse Generator Without H-Bridge Controlled by a Magnetically Isolated Driver

Abstract

Based on the widespread application of pulsed power technology in food safety and medicine, this article develops a bipolar pulsed power generator without an H-bridge controlled by a magnetically isolated driver. The main circuit of the developed pulse power supply adopts the positive- and negative-polarity Marx circuit cascade, which can output bipolar high-voltage pulses without any auxiliary circuits. Moreover, the main circuit has added anti-straight-through diodes. These diodes can truncate the short-circuit current generated when a straight-through short-circuit fault occurs in the circuit, safeguarding the switches and enhancing the power supply stability. In addition, the switching drive scheme uses a series core magnetic ring and the secondary-side windings in anti-parallel, requiring only two drive signals to achieve separate control of the four sets of switches in the bipolar pulse generator. According to the proposed main circuit structure and driving scheme, the simulation of the main circuit and driving circuit are conducted to lay a theoretical foundation for developing the prototype. Subsequently, a 20-stage prototype of a bipolar pulse generator is created. The experimental results show that the system can generate bipolar high-voltage pulses with a voltage amplitude of $0~\sim ~\pm 15$ kV, a pulsewidth of 1– $10~\mu $ s, and a repetition frequency of 0–1 kHz. The interval time between positive and negative pulses can be flexibly adjusted.