考虑绝缘介质非线性特性的高压阀侧套管电热耦合模型研究  

Research on Model of Electro-thermal Coupling in Valve Side Bushing Considering Nonlinear Characteristics of Capacitor Core Insulation Medium

作　　者：何永胜 张施令 杨帆[2] 鲁宗相[3] HE Yongsheng;ZHANG Shiling;YANG Fan;LU Zongxiang(State Grid Chongqing Electric Power Company,Yuzhong District,Chongqing 400015,China;State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Shapingba District,Chongqing 400044,China;Department of Electrical Engineering,Tsinghua University,Haidian District,Beijing 100084,China)

机构地区：[1]国网重庆市电力公司,重庆市渝中区400015 [2]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市沙坪坝区400044 [3]清华大学电机工程与应用电子技术系,北京市海淀区100084

出　　处：《电网技术》2025年第4期1689-1697,I0076-I0078,共12页Power System Technology

摘　　要：特高压换流变压器阀侧套管工作在电场、温度场和机械应力场多场耦合环境,电容芯子内部出现温度和电场不均匀分布,亟需将绝缘介质非线性特性引入到阀侧套管的电热耦合机理并开展优化设计。该文模拟了直流分量和多次谐波分量激励下阀侧套管的复杂电场和温度分布,建立了阀侧套管电容芯子发热模型,创新提出了考虑电容芯子绝缘材料非线性特性的阀侧套管电热耦合非线性模型。研究表明:特高压阀侧套管在正常工作时承受电压和电流除50Hz工频分量外,存在复杂谐波分量和直流分量,在频率分量达到2500Hz后其波形幅值趋近于零。随温度在区间[20,110]℃升高和频率在区间[10^(-1),10^(6)]Hz降低,损耗角正切值参数显著增大且存在多处波峰和波谷区域,材料介电常数和温度、频率之间呈现出明显的非线性关系。该文提出的阀侧套管电热耦合非线性模型形成了电热耦合非线性改进等裕度设计方法,实现了套管芯子径向场强最大值为5.85kV/mm,轴向场强为0.41kV/mm,局部放电裕度值为1.29。阀侧套管芯子极板间轴向场强实现均匀分布,验证了阀侧套管电热耦合非线性模型的合理性。该文模拟数据可为特高压阀侧套管的设计制造提供理论支撑,对于保障特高压直流输电工程安全可靠运行具有一定指导价值。The valve side bushing of the ultra-high voltage converter transformer operates in the multi-field coupling environment of the electric field,temperature field,and mechanical stress field.The capacitor core has an uneven distribution of temperature and electric field.It is urgent to introduce nonlinear characteristics of the insulation medium into the electric thermal coupling mechanism of the valve side bushing and carry out optimization design.This article simulates complex electric field and temperature distribution of the valve side bushing under the excitation of DC and multiple harmonic components,establishes a heating model of valve side bushing capacitor core and proposes valve bushing electric-thermal coupling model considers nonlinear characteristics of capacitor core insulation material.Research has shown during normal operation,the bushing on the side of the ultra-high voltage valve bears harmonic components and DC components in addition to 50Hz power frequency components.After the frequency component reaches 2500Hz,the waveform amplitude approaches zero.As temperature increases in range of[20,110]℃and the frequency decreases in range of[10^(-1),10^(6)]Hz,the tangent value parameter of loss angle increases and there are multiple peaks and valleys.There is a clear nonlinear relationship between the dielectric constant of material and temperature and frequency.The nonlinear model of the valve side bushing electric thermal coupling proposed in the article forms an improved equal margin design method for the electric thermal coupling,achieving the maximum radial field strength of 5.85kV/mm,the axial field of 0.41kV/mm,and the partial discharge margin value of 1.29 for the casing core.The comparison between the calculation and design shows that the axial field strength between the core plates of the valve side sleeve is distributed,which verifies the rationality of the nonlinear model of the valve side sleeve electric thermal coupling.Simulated data in this article can provide theoretical support for man

关 键 词：阀侧套管 电热耦合模型 电容芯子绝缘材料 非线性 

分 类 号：TM721[电气工程—电力系统及自动化]