Design and Implementation of 40-kV Active Pull-Down Pulsed-Power Modulator for Driving Plasma Reactor in Gas Abatement

This study deals with 40-kV active pull-down pulsed-power modulator for driving plasma reactor in gas abatement. Plasma reactors for industrial gas processing have capacitive load characteristics. Moreover, when a voltage of several tens of kV is applied, a corona discharge is generated that induces a decomposition reaction of the flowing industrial gas. To increase gas processing efficiency, tens of kV of pulsed-power are required with a fast-rising rate, short pulse width, and high repetition rate. In this study, a 40-kV solid-state pulsed power modulator with an active pull-down circuit that enables a sub-microsecond pulse output under plasma reactor load conditions is proposed. The proposed modulator consists of a capacitor charger, a discharge circuit, and a pull-down circuit. The design of the pulsed modulator based on a modular structure, and solutions for achieving reliable operation are presented. Strategy for gate-driving, designing the integrated gate driver circuit, and efficient high voltage isolation are introduced. The pulse output performance of the implemented 40-kV active pull-down pulsed-power modulator is verified under a plasma reactor load (1000-mm, Φ100-mm) condition.