标题:
恒定电压下变压器油隙放电特性Discharge Behaviors of Transformer Oil-Gap under Constant Voltage
作者:
李伟, 任志刚, 石磊, 辛锋, 马光耀, 郑殿春, 王正伟
关键字:
变压器油, 场致电离, 载流子, 空间电荷, 流注Transformer Oil, Field Ionization, Charge Carriers, Space Charge, Streamer
期刊名称:
《Advances in Condensed Matter Physics》, Vol.5 No.4, 2016-11-18
摘要:
以变压器油作为研究对象，采用有限元方法(finite element method, FEM)对应用场致电离机理建立的用于表述液体电介质流注放电过程中载流子的产生及输运特性的偏微分方程(partial differential equations, PDE)进行求解分析，获得直流电压下变压器油隙放电过程空间电荷动力学特性。数值模拟结果表明，场致电离导致液体击穿的根本原因是油隙中自由载流子的产生、迁移形成了预击穿电流，由此产生的焦耳热使得油隙中形成低密度区，利于流注发展。根据这些现象得出的结论能够很容易理解液体电介质的击穿机理，有利于液体电介质在电力系统领域得到更合理的应用。
The transformer oil was taken as the object of study, and the finite element method (FEM) was employed to analyze and solved the partial differential equations (PDE) which was built by field ionization for describing the generation and transport properties of free charge carriers. The results showing that the dynamic characteristics of space charges in the liquid-gap discharge under DC were gained. According to the simulating results, the fundamental causes of the dielectric liquids breakdown by the electric field dependent molecular ionization are described as following; the pre-breakdown current is firstly formed by the generation and migration of the charge carriers in the oil gap, then the joule heat generated from it makes liquid-gap to form the low density region in the liquid, which facilitate initiated little streamer emergence as avalanche in gas discharge, meanwhile, the streamer is continuously evolving. Then these conclusions enable ones easily understand breakdown mechanism of the liquid dielectrics that are reasonably applied to power system fields.