A Transition Arm Modular Multilevel Universal Pulse-Waveform Generator for Electroporation Applications

IEEE Trans. Plasma Sci.

Darwish

Ahmed

et al. 2017

Self Cite

The Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output.Abstract-High voltage (HV) pulses are used in pulsed electric field (PEF) applications to provide an effective electroporation process, a process in which harmful microorganisms are disinfected when subjected to a PEF. Depending on the PEF application, different HV pulse specifications are required such as: the pulse-waveform shape, the voltage magnitude, the pulse duration, and the pulse repetition rate. In this paper, a generic pulse-waveform generator (GPG) is proposed, the GPG topology is based on half-bridge modular multilevel converter (HB-MMC) cells. The GPG topology is formed of four identical arms of series connected HB-MMC cells forming an H-bridge. Unlike the conventional HB-MMC based converters in HVDC transmission, the GPG load power flow is not continuous which leads to smaller size cell capacitors utilization, hence smaller footprint of the GPG is achieved. The GPG topology flexibility allows the controller software to generate a basic multilevel waveform which can be manipulated to generate the commonly used PEF pulse-wave forms. Therefore, the proposed topology offers modularity, redundancy and scalability. The viability of the proposed GPG converter is validated by MATLAB/Simulink simulation and experimentation.Index Terms-bacterial decontamination, electroporation, HBridge, modular multilevel converters (MMC), pulsed electric field, pulse waveforms generator.

Section: Simulation Resultsmentioning

confidence: 99%

A Modular Multilevel Generic Pulse-Waveform Generator for Pulsed Electric Field Applications

IEEE Trans. Plasma Sci.

Darwish

Ahmed

et al. 2017

Self Cite

“…As the pulse voltage magnitude increases, it is desirable to reduce the PG ⁄ to reduce the EMI level. Several recent PGs utilize the MMC HB-SM for such a task, [13]- [14] and [19]. However, generating multilevel pulse waveforms is not possible without assuring balance of the individual SMcapacitor voltages.…”

Section: A Principle Of Operationmentioning

confidence: 99%

“…In [12] the HB-SM capacitors are charged sequentially then connected in series to discharge into the load. The reduced / feature inherited in multilevel converters for HVDC transmission applications, has been utilized to generate reduced / pulse waveforms to decrease the converter's electromagnetic interference (EMI) [18]- [19]. In [20], with two H-bridges fed from two isolated DC input sources, a bipolar PG is proposed but providing the isolated DC sources to the H-bridges is not addressed.…”

Section: Introductionmentioning

confidence: 99%

Full-Bridge Modular Multilevel Submodule-Based High-Voltage Bipolar Pulse Generator With Low-Voltage DC, Input for Pulsed Electric Field Applications

Abdelsalam

IEEE Trans. Plasma Sci.

Ahmed

et al. 2017

Self Cite

High voltage (HV) pulse generators (PGs) are the core of pulsed electric field applications. Applying HV pulses produces electrical pores in a biological cell membrane, in which if the size of the pores increases beyond a critical size, the cell will not survive. This paper proposes a new HV-PG, based on the modular multilevel converter with full-bridge sub-modules (FB-SMs). In order to alleviate the need of complicated sensorless or sensor based voltage balancing techniques for the FB-SM capacitors, a dedicated self-regulating charging circuit is connected across each FB-SM capacitor. The individual capacitor charging voltage-level is obtained from three successive stages namely: convert the low-voltage DC input voltage to a highfrequency square AC voltage; increase the AC voltage-level via a nano-crystalline step-up transformer; and rectify the secondary transformer AC voltage via a diode full-bridge rectifier. The HV bipolar pulses are formed across the load in a fourth stage through series connected FB-SMs. The flexibility of inserting and bypassing the FB-SM capacitors, allows the proposed topology to generate different pulse-waveform shapes, including rectangular waveforms with specifically reduced / and ramp pulses. The practical results, from a scaled down experimental rig with five FB-SMs and a 1kV peak to peak pulse output, validate the proposed topology.

“…For a successful IRE process, the strength of the applied electric field, typically ranges between 2.5 kV/cm to 12 kV/cm, according to the type of the harmful microorganism and the application [4]. Applying HV pulses in kV range and microsecond range should deactivate the harmful microorganisms in the water under treatment [5]. Therefore, HV pulse generators (PGs) are the pillar of IRE application, and should meet several challenging aspects such as modularity, scalability and flexibility [6].…”

mentioning

confidence: 99%

“…The existing modularity with modular multilevel converter (MMC) sub-modules (SMs) has been harnessed to generate HV pulses for IRE [8]- [14]. Not only conventional rectangular pulse-waveforms can be generated by MMC based PGs, but a wide range of pulse-waveforms is also possible [5] and [10]. The majority of these topologies require an HVDC input supply and the obtained pulse peak-voltage is that of the input HVDC level.…”

mentioning

confidence: 99%

A Step-Up Modular High-Voltage Pulse Generator Based on Isolated Input-Parallel/Output-Series Voltage-Boosting Modules and Modular Multilevel Submodules

Darwish

IEEE Trans. Ind. Electron.

Finney

et al. 2019

Self Cite

Irreversible electroporation for disinfection applications involve exposing the specimen cellmembrane 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 inputparallel/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.