低频电压下含纤维素颗粒变压器油绝缘特性及影响因素  

Insulation Characteristics and Influencing Factors of Transformer Oil Containing Cellulose Particles under Low-Frequency Voltage

作　　者：刘云鹏[1,2] 赵家莹 刘贺晨 赵涛[1] 尹子澳 Liu Yunpeng;Zhao Jiaying;Liu Hechen;Zhao Tao;Yin Ziao(Hebei Key Laboratory of Green and Efficient New Electrical Materials and Equipment North China Electric Power University,Baoding 071003 China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University,Beijing 102206 China)

机构地区：[1]华北电力大学河北省绿色高效电工新材料与设备重点实验室,保定071003 [2]新能源电力系统国家重点实验室(华北电力大学),北京102206

出　　处：《电工技术学报》2024年第4期1198-1207,共10页Transactions of China Electrotechnical Society

基　　金：国网浙江省电力有限公司科技资助项目(5211DS22000D)。

摘　　要：低频变压器是低频输电系统中的关键设备,低频电压下的绝缘特性对其设计及运行具有重要意义。该文为了研究低频电压下含纤维素颗粒的变压器油的绝缘特性,分别研究20、30、40、50 Hz四种频率交流电压下不同纤维素颗粒度(低、中、高)水平的变压器油击穿特性。同时,通过仿真及试验分析不同频率下变压器油中纤维素颗粒运动及积聚过程。研究结果表明,交流电压频率对变压器油中纤维素颗粒的成桥特性及击穿电压具有显著影响。随着频率的降低,纤维素颗粒向电极移动速度变慢并难以黏附在电极表面,减缓了纤维素颗粒在电极表面的积聚过程及杂质小桥的形成速度。相同频率交流电压下,变压器油击穿电压均随颗粒物浓度的升高而降低;相同纤维素颗粒浓度下,变压器油击穿电压随着频率的降低而增大。研究结果为低频变压器的设计及运行维护提供了基础数据支撑。Low-frequency transformer is the key equipment in low-frequency transmission systems,and its insulation characteristics under low-frequency voltage are important for its design and operation.In this paper conducted transformer oil breakdown tests at different cellulose particle size(low,medium,and high)levels to study the insulation characteristics of transformer oil containing cellulose particles under low-frequency voltage.The test frequency was selected as 20,30,40,and 50 Hz,and the content of cellulose particles in oil samples was selected as low,medium,and high particle size levels.According to the IEC 60156 standard,the pressure was increased step by step at a constant rate of 2 kV/s to the oil sample breakdown,and the oil sample in the oil cup was replaced every 6 times after the breakdown.In order to ensure the consistency of the test,30 times of breakdown tests were repeated respectively at each frequency and particle size level,and the effective value of breakdown voltage was recorded.The Weibull distribution method was used to analyze the test results.The test results show that at the low particle size level,the breakdown voltage at 50 Hz is taken as the reference,and the breakdown voltage at 20,30,and 40 Hz is increased by 12.25%,25.62%,and 39.14%,respectively.At the high particle level,the breakdown voltage increases by 21.45%,83.69%,and 97.30%at 20,30,and 40 Hz,respectively.At the same time,the accumulation process of cellulose particles at the electrode was observed by experiments,and the movement of cellulose particles in transformer oil at different frequencies was analyzed by multi-physical field simulation.In this paper,an observation test was carried out on the motion characteristics of cellulose particles for transformer oil with high particle size levels.18 kV was selected as the test voltage and carried out at room temperature.The distribution state of cellulose particles between electrodes was observed with a camera.Finally,COMSOL finite element software“AC-DC module”and“Particle tra

关 键 词：变压器油 交流电压 低频输电 纤维素颗粒 运动 

分 类 号：TM41[电气工程—电器]