A solid state high voltage-pulsed electric field generator for application in food processing

Abstract

High-voltage pulsed power is nowadays a very important research field and an expanding industrial technology with major worldwide economical impact, this technology being used in different applications (food processing, medicine…). For the development of PEF technology, it is necessary to have a wide variation interval of the different pulse parameters (amplitude, pulse width, frequency …). Conventional pulse generators do not allow it, prompting the researchers to focus on the development of pulse generators to make them more versatile to be used in different applications. With the development of solid-state electronics, solid-state devices are becoming more and more suitable for pulsed power application. They could provide the pulsed power systems with compactness, reliability, high repetition rate, and long life time. The rising of pulsed power generators using solid-state devices eliminates limitations of conventional components, and promises pulsed power technology to be widely used in commercial applications. However, solid-state switching devices such as Insulated Gate Bipolar Transistor (IGBT) available now are only rated up to a few kilo Volts. Most of pulsed power systems demand much higher voltage ratings. The aim of the present work is the development of a Marx modulator which is a unique circuit intended for voltage multiplication. Its functioning is based on charging capacitors in parallel and discharging them in series into the treatment chamber. The Marx bank developed comprises four stages, was constructed using 1200 V IGBTs and 10 µF capacitors. This generator is versatile; several factors could be varied such as the voltage level up to 3.6 kV, the repetition rate and the pulse width.