A step-up modular high-voltage pulse generator based on isolated input-parallel/output-series voltage-boosting modules and modular multilevel sub-modules

Irreversible electroporation for disinfection applications involve exposing the specimen cell-membrane to a pulsed electric field in order to kill harmful microorganisms. High voltage (HV) pulses, of relatively short durations in range of few micro-seconds, are generated across the sample chamber. The HV pulse specifications such as: voltage magnitude, waveform, repetition rate, and duration differ according to the conditions of the sample being processed. This paper proposes a new step-up power electronic converter topology for generating the required HV pulses from a relatively low input voltage. The converter consists of two main stages; the first stage is responsible for boosting the input voltage to the desired level using input-parallel/output-series connected dc/dc modules while the second stage forms the required HV pulses with the proper magnitude, duration and repetition rate using modular multilevel converter sub-modules. The proposed topology is able to produce the HV pulses with controlled voltage and current stresses across the employed semiconductor switches and diodes, hence, it can be implemented with the market-available semiconductor technology. Mathematical analysis of the proposed topology is developed and MATLAB/Simulink simulation results explore operational conditions. Experimental results from a scaled-down prototype validate the functionality of the proposed system.