摘要
随着新型电力系统快速发展,油纸绝缘承受的电应力环境更加复杂,其中暂态脉冲下的油纸绝缘放电行为备受关注。为弥补实验研究洞察微观机理能力的不足,基于全电流理论构建油中流注场路耦合模型,研究了脉冲电压下流注演变规律及其影响因素,揭示了放电脉冲波形特性及其与流注演变过程的内在联系。研究表明:暂态脉冲作用下的油中流注可分为球状发展、定向发展、流注消散3个阶段;流注头部场强在球状发展阶段减弱,定向发展阶段维持不变,流注头部净电荷密度始终减弱;起始放电电压的增加、直流分量占比的减小、脉冲陡度的增加均会使流注传播速度与最大半径增加;忽略回路电感作用时,流注将诱发单极性双峰放电脉冲,其中球状发展阶段对应脉冲首峰前沿,定向发展阶段对应首峰下降沿,纸板充电过程对应次峰前沿,电荷消散过程对应次峰下降沿;回路电感将引起放电脉冲的首峰振荡,振荡频率、脉冲幅值均与回路电感近似线性负相关。该研究结果为揭示暂态电应力下油纸绝缘放电机理奠定了理论基础,对统一放电脉冲波形特性具有重要意义。
With the development of new power systems,the electrical stress environment of oil-paper insulation becomes more complex,and the discharge behavior of oil-paper insulation under transient voltage has attracted much attention.In order to make up for the insufficiency of insight into the microscopic mechanism through experimental research,a field-circuit coupling model of streamer in transformer oil is constructed based on the total current theory,and the evolu-tion law of streamer at impulse voltage and its influencing factors are studied.The waveform characteristics of discharge pulse and its internal relationship with the streamer evolution are revealed.The results show that the streamer in trans-former oil at transient pulse can be divided into three stages,namely,spherical development,directional development,and streamer dissipation.The field strength at streamer head decreases in the spherical development stage,but remains un-changed in the directional development stage,and the density of net charge at streamer head always decreases.The increases of initial discharge voltage and pulse gradient as well as the decrease of DC component will increase the streamer propagation velocity and maximum radius.When the loop inductance is ignored,the streamer causes unipolar bipeak discharge pulse.The spherical stage,the directional stage,the pressboard charging process,and the charging dis-sipation process correspond to the first peak rising edge,the first peak falling edge,the sub-peak rising edge,and the sub-peak falling edge,respectively.The loop inductance causes oscillations in the first peak,and the oscillation frequency and pulse amplitude are approximately linearly negatively correlated with the loop inductance.This study lays a theoreti-cal foundation for revealing the discharge mechanism of oil-paper insulation under transient voltage and has important significance for uniforming the waveform characteristics of discharge pulse.
作者
李斯盟
崔树群
杨宇翔
邸振国
汲胜昌
秦锋
LI Simeng;CUI Shuqun;YANG Yuxiang;DI Zhenguo;JI Shengchang;QIN Feng(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China;State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Northwest Institute of Nuclear Technology,Xi’an 710024,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2024年第9期4207-4221,共15页
High Voltage Engineering
基金
国家自然科学基金(52007148)
强脉冲辐射环境模拟与效应全国重点实验室开放基金(SKLIPR2114)。
关键词
油纸绝缘
场路耦合
局部放电
空间电荷
纳秒脉冲
全电流
oil-paper insulation
field-circuit coupling
partial discharge
space charge
nanosecond pulse
full current
