高功率火花間隙開關構型優化設計模擬

Abstract

本文研究的高功率火花間隙開關廣泛地應用於建築物爆破拆除與軍事科技的 火工品起爆裝置。為了瞭解火花間隙開關的操作特性，本文收集高電壓火花間隙放電的文獻資料，彙整高電壓火花氣體間隙放電的物理機制，歸納放電的條件與參數，建立代數型試算表，以提供快速的設計參考準則。為了更深入瞭解火花間隙開關內的電場動態變化，本論文利用COMSOL 多重物理計算軟體與電漿模組，建立2 維軸對稱模型，電極間隙中的工作氣體為氬氣，在一大氣壓的環境下，模擬高電壓場內的電子與離子等生成反應與傳輸現象，瞭解觸發過程中的動態電場強度分佈、電荷密度與通量等變化，以優化高功率火花間隙開關的構型設計參數。 本文模擬的參數包含電極間隙距離、觸發極電壓、正極電壓等不同情況下， 探究火花間隙開關的作動行為，分析其電流通量和各參數之間的關係。本文所計算不同參數的八個算例結果顯示，導通的脈衝電流皆可以引爆特定的金屬銅箔電橋，這表示每個算例的電流值可以達到4.3X10^3A，反應速率僅為十餘奈秒。

High power spark gap switches have a large variety of applications from military science to demolition of buildings. To explore performances and design parameters of spark gap switches, literature of spark gap discharge were surveyed thoroughly. Various mechanisms of gas discharges were reviewed so that conditions and parameters in discharge channels were examined for the guideline of design. An Excel table was established to quick reveal parameters and performance of the designed gap switch. In order to gain a better understanding of scenarios of electric field in the spark gap switches, a set of partial differential equations governing transports of electrons and ions in the gap were numerically solved to simulate time-dependent physical fields. Custom models were coded and linked with COMSOL software package for numerical simulation using an axisymmetric frame. The working gas in the gap is argon at one atmospheric pressure. Detail electric charge intensities and fluxes can provide valuable information to deduce design optimizing of a spark switch. This thesis explores the reaction of spark gap switches under several circumstances and analyzes the dependences of design parameters and pulsed current flux. The parameters involved in analysis include gap distance, the voltage applied to anode and the voltage applied to trigger. The eight simulation cases demonstrated that the conducted pulsed currents could promptly ignite the selected copper foil bridges. It evidences that the current value for each case can meet 4.3X10^3A in the order of ten nano seconds.