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High-Voltage pulse generators are commonly used in biotechnology, medicine, industrial applications, food processing and drinking water purification. The dc-dc boost converter has been used before in pulsed applications for its ability to amplify a relatively low input dc voltage to a high-voltage output. A high-voltage solid-state chopping switch is then used to chop the generated high output voltage. In this work, a boost-converter based ringing circuit with high voltage gain is proposed for water treatment applications. The basic concept of the proposed approach depends on operating the boost converter under discontinuous current conduction. With the proposed approach, the chopping high-voltage switch at the output stage is eliminated, which positively affects the system cost and efficiency. A full-design of the circuit and passive components is presented to ensure that the desired pulse specifications are achieved. The proposed approach has been validated using simulation and experimental results. [ABSTRACT FROM AUTHOR]

Conventional Modular Multilevel Converter (MMC) with Half-Bridge Sub-Modules (HB-SMs) can be used effectively as a solid-state high-voltage pulse generator to chop a high-voltage dc input into a bipolar pulsed output voltage without employing neither high-voltage semiconductor switches nor series-connected switches. Nonetheless, its boosting capability is constrained. In this paper, a hybrid boost MMC-based bipolar high-voltage pulse generator is proposed where each arm contains a combination of Full-Bridge SMs (FB-SMs) and HB-SMs. The HB-SMs and FB-SMs have the same rated voltage. The proposed approach is able to generate bipolar pulses, and operates with a wide range of boosting capability. Detailed illustration of the proposed configuration and its operational concept are presented. Simulation models for the proposed approach are built, for different FB-SMs to HB-SMs ratios, using Matlab/Simulink platform. Experimental results for a scaled-down prototype are presented to validate the concept. [ABSTRACT FROM PUBLISHER]

The conventional unipolar Marx generator can be employed for bipolar pulsed electric field by adding a high-voltage H-bridge at the load side which necessitates stacked switches. Alternatively, bipolar Marx generator with low-voltage switches can be employed. The existing bipolar Marx generators are typically fed from dc supplies, where polarized capacitors are employed. The capacitance of involved capacitors is selected such that the total energy stored in the generator's capacitors is higher than the bipolar pulse energy. As a result, polarized capacitors with relatively high capacitances are required. In addition, a high number of controlled switches per stage are required (at least four switches per stage). In this paper, a new solid-state bipolar Marx pulse generator with only three controlled switches per stage is proposed. The proposed generator is fed from sinusoidal/square ac voltage and non-polarized capacitors with low capacitance are employed. The proposed bipolar Marx-generator can be used effectively with resistive loads for exponential pulse generation. A detailed illustration of the proposed approach is presented and a discussion, to elucidate the differences between the proposed pulse generator and the other existing ones, are presented. Simulation results for the proposed pulse generator are presented to validate the concept. Finally, experimental results have been obtained from a low-voltage model of the proposed generator. [ABSTRACT FROM AUTHOR]

Pulsed electric field (PEF) can be used effectively in water treatment applications by passing infected water through two electrodes excited from a high voltage pulsed power supply which guarantees killing the harmful germs. In this paper, a new high-voltage pulse-generator with closed loop control of its output voltage is presented for treating water via underwater pulsed streamer corona discharge. The proposed generator is fed from a low AC voltage source (utility mains 220 V, 50 Hz) which makes it suitable for domestic applications. The proposed topology provides transformer-less operation which reduces the system size and enhances the overall efficiency. The proposed topology is based on capacitor-diode voltage multiplier (CDVM) circuits in conjunction with DC-DC converters (Boost and Buck-Boost converters). The simulation and experimental results elucidate the proposed configuration. [ABSTRACT FROM AUTHOR]