Design of a high-voltage multiplier combined with Cockcroft-Walton voltage multipliers and switched-capacitor AC-AC converters

Abstract

In recent years, the non-thermal food processing is receiving much attention, because the non-thermal food processing can offer nutritious and fresh processed foods at low cost. In the non-thermal food processing, an underwater shockwave is utilized by discharging a high voltage in water. To generate the underwater shockwave, this paper proposes a novel high voltage multiplier designed by connecting a bipolar Cockcroft- Walton voltage multiplier (CWVM) with a switched-capacitor (SC) direct ac-ac converter in series. In the proposed multiplier, first, an ac input is amplified to double by the inductor-less ac-ac converter. Then, the output of the ac-ac converter is stepped-up again by the bipolar CWVM. Therefore, owing to the inductor-less series-connected bipolar topology, the proposed multiplier can achieve smaller size and higher gain than existing multipliers. Concerning the proposed multiplier with 26 × step-up gain, the operation principle and theoretical analysis are discussed in detail. Furthermore, the feasibility and effectiveness of the proposed multiplier are demonstrated by simulation program with integrated circuit emphasis (SPICE) simulations.