Electrostatic Analysis of Compact Modular High-Voltage Insulation Structures for High-Power RF Devices

Abstract

High-voltage insulation structures are critical in interfacing high-power radio frequency (RF) devices with pulsed power sources (PPSs). These structures are intended to carry hundreds of kilovolts and tens of kiloamperes of pulsed power. They commonly suffer from breakdown during the operations due to the high electric stress encountered. In this study, we present an electrostatic analysis of a high-voltage structure in three different dielectric regions—transformer oil, solid insulator (nylon), and vacuum. Two types of structures, namely, nylon-based structure (structure-1) and alumina-based structure (structure-2), are analyzed. The geometries are modeled, simulated, and analyzed using ANSYS Maxwell 3-D in DC conditions. The objective of the study is to investigate the electric field distribution and identify the peak electric field value in each region of the structures. The structures which are studied in this article are generally used in integrating the high-power RF device with a pulsed power system. The peak electric field value and its location are critical in assessing breakdown risk. Fixed voltages of 400 and 600 kV are applied between the electrodes separated by dielectric material. Appropriate dielectric properties are selected for the regions to closely represent the practical conditions. Peak electric field value and its location are thoroughly checked with different mesh counts to minimize the numerical errors. The simulated results of the high-voltage structures are validated through experiments, and the structure successfully withstood the high-voltage pulse without dielectric breakdown. The simulation study is extended to a compact and modular alumina-based structure (structure-2) that serves as an ultrahigh vacuum (UHV) envelope as well as high-power devices.