Conceptual Study of a Bipolar Modular High Voltage Pulse Generator with Sequential Charging

Repetitive Pulsed Electric Field (PEF) is a common technique for disinfecting liquids. By applying adequate PEF across germ cell membranes, an irreversible electroporation process, and cell destruction can be achieved. The PEF can be generated by applying a repetitive pulsed voltage using a high-voltage pulse generator across the cell membrane. Unipolar and bipolar high-voltage pulse generators are commonly used. Bipolar pulse generators can be implemented by employing a unipolar generator with an H-bridge output stage. The main disadvantage of this method is that the switches of the H-bridge are rated at the output high-voltage level, i.e. series-stacked semiconductor devices should be employed with static and dynamic voltage sharing to implement high-voltage switches. In this paper, a half-bridge submodule-based bipolar modular high-voltage pulse-generator fed from a relatively low-voltage dc supply is proposed. In the proposed approach, relatively low-voltage Insulated Gate Bipolar Transistors (IGBTs) are required to generate the high-voltage bipolar pulses. A detailed illustration of the proposed concept is presented. Simulation results are used to assure the viability of the proposed concept. Finally, experimental results have been obtained from a low-voltage model of the proposed generator.