High‐voltage pulse generator based on sequentially charged MMC‐SMs operating in a voltage‐boost mode

Abstract

Pulse forming networks and Marx generators are the classical rectangular waveform pulse generators (PGs). They are inflexible and their capacitors must be fully charged to the required voltage from 0V before delivering each high-voltage (HV) pulse. They are only able to generate unipolar pulses; if bipolar pulses are sought another generator fed from a negative supply voltage is added. Recently, several power electronics based PGs have been proposed. This paper presents an HV power electronics based PG, which is based on Half-Bridge Modular Multilevel Converter (HB-MMC) sub-modules (SMs) charged sequentially in a voltage boost mode. Each SM capacitor and main switch form a boost converter with the charging input supply and inductor. As a result, all SM capacitors are charged to a voltage greater than the input. During the discharging process the SM capacitors are connected in series, producing a rectangular HV pulse across the load. The proposed charging method allows a reduction in the converter footprint in comparison with recently proposed MMC sequentially charged PG topologies. Although only rectangular pulse waveforms are sought in this paper, a SM capacitor voltage balance method allows multilevel pulse generation. The viability of the proposed converter is confirmed by MATLAB/Simulink simulation and scaled-down experimentation.ReView by River Valley Technologies IET Power Electronics 2018/12/10 16:12:53 IET Review Copy Only 2This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication in an issue of the journal. To cite the paper please use the doi provided on the Digital Library page. Ref Time: 50 µs/div. Voltage: 100 V/div. Ref Time: 50 µs/div. Voltage: 40 V/div. Ref Time: 50µs/div. Current: 1A/div. Time: 5µs/div. tL tC Ref Time: 50 µs/div. Voltage: 200 V/div. Ref Time: 50 µs/div. Voltage: 40 V/div.

High-Voltage Pulse Generators for Electroporation Applications: A Systematic Review

“…The structure presented in [77] is the same in [76], except that instead of the rL branch, only L is used, and a series connection of diodes in reverse blocking switches is used because these two switches are exposed to reverse HV during pulse generation. There is no need for a voltage sensor to generate rectangular pulses.…”

“…voltage gain, but in the meantime, voltage gain of [79] is (due to the use of an SC converter), and the voltage gain of [23] and [77] is equal to (due to the use of a Boost converter). Voltage gain in [78]- [81] has other parameters that must be considered in the calculations.…”

A Modular Multilevel Voltage-Boosting Marx Pulse-Waveform Generator for Electroporation Applications

“…Reference [36] presents an improvement by charging two SM capacitors (one from the upper arm and one from the lower arm) simultaneously. Adding a boost converter in the input stage with sequential charging, as in [37], deteriorates the repetition time as the charging time of the SM capacitors is divided into two parts. First, the boost converter inductor is energized, and then the capacitor is charged.…”

“…First, the boost converter inductor is energized, and then the capacitor is charged. The topology in [36]- [37] is constrained to rectangular pulses and requires switches with reverse blocking capabilities [38]- [39].…”

Classification and comparative study of EDM pulse generators

“…The difference in typical ratings is as follows: power (several GW versus several hundred W), voltage (several kV versus several 100 s V) and current (several kA to several A) [1, 15–17]. They are also distinct from the conventional high‐voltage pulse generators [18]. To this end, this paper presents a classification and comparative study from efficiency and control perspective for the first time considering 13 important topologies.…”