换流变压器用有载分接开关过渡电阻温升的动态仿真  

Simulation on Dynamic Temperature Rise of Transition Resistance in On-Load Tap-Changer Used in Converter Transformer

作　　者：高煜 赵学童[1] 李刚 汪可 杨丽君[1] Gao Yu;Zhao Xuetong;Li Gang;Wang Ke;Yang Lijun(National Key Laboratory of Power Transmission Equipment Technology,Chongqing University,Chongqing,400044,China;China Electrical Power Research Institute,Beijing,100192,China)

机构地区：[1]输变电装备技术全国重点实验室(重庆大学),重庆400044 [2]中国电力科学研究院有限公司,北京100192

出　　处：《电工技术学报》2025年第7期2226-2235,共10页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划资助项目(2021YFB2402100)。

摘　　要：有载分接开关是换流变压器的核心部件,主要用于精准调节换流变压器的电压以及稳定输送直流功率。分接开关调压范围大、操作频繁,在调压过程中环流流过过渡电阻会产生较高的热量,过渡电阻的状态对换流变压器有载分接开关的安全运行至关重要。因此,开展有载分接开关切换过程中过渡电阻的温升特性研究,对保障特高压直流输电与电网运行安全具有重要意义。该文利用COMSOL Multiphysics仿真软件,建立特高压换流变压器用有载分接开关过渡电阻在真实运行工况下的电-热耦合模型,针对不同的负载工作状态,分别计算过渡电阻的温度分布,揭示了有载分接开关切换过程中过渡电阻的变化及其对分体式布置油室温升的影响。研究发现,过渡电阻的表面温度随着分接开关切换次数的增加呈现“锯齿状”的先快速上升,然后趋于平缓的变化规律,并进行了实验验证。通过进一步开展不同负载容量下过渡电阻的温升研究,建立了过渡电阻温升的评估模型和评估函数,为实际换流变压器有载分接开关的运行维护提供了理论指导。The on-load tap changer is a core component of the converter transformer,mainly used to accurately adjust the voltage of the converter transformer,and thus stabilize the transmission of DC power.The on-load tap changer provides an extraordinary capacity of wide voltage regulation range and frequent operation.During the voltage regulation process,the circulating current flows through the transition resistance and generates high heat.The state of the transition resistance is crucial for the safety of the on-load tap changer in the converter transformer.Therefore,it is of great significance to clarify the temperature rise characteristics of transition resistance during the switching process of on-load tap changer for ensuring the safety of the ultra-high voltage direct current transmission system and power grid operation.In this work,an electrical-thermal coupling model was established using the COMSOL Multiphysics software and the temperature rise of the transition resistance of on-load tap changer in converter transformer was simulated under real operating conditions.The temperature distribution of the transition resistance is calculated under different workloads,revealing the temperature evolution of the transition resistance and its impact on temperature of the separate oil chamber during the switching process of the on-load tap changer.It was found that the surface temperature of the transition resistance firstly increases sharply in a zigzag pattern with the switching action of the on-load tap changer,and then slightly increases to a stable temperature,which was validated by temperature-measuring experiment of the transition resistance.By conducting research on the temperature rise of transition resistors under different load capacities,a model of the maximum temperature of transition resistors changing with load capacity was established.It was found that the maximum temperature rise during the transition resistor switching time series showed a linear relationship with load capacity.By further studying the tem

关 键 词：换流变压器 有载分接开关 过渡电阻 温升仿真 有限元法 

分 类 号：TM403.4[电气工程—电器]