暂态时变负荷下避雷器热散逸模型  

Heat Dissipation Model of Arrester Under Transient Time-varying Load

作　　者：方针 吴小可 郭洁[2] 谢鹏康 胡建平 李超 FANG Zhen;WU Xiaoke;GUO Jie;XIE Pengkang;HU Jianping;LI Chao(Key Laboratory of State Grid Hunan Disaster Prevention and Mitigation Center,Changsha 410129,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]湖南电网防灾减灾国家重点实验室,长沙410129 [2]西安交通大学电力设备电气绝缘国家重点实验室,西安710049

出　　处：《高电压技术》2020年第8期2968-2975,共8页High Voltage Engineering

摘　　要：由于Zn O电阻片的阻抗在实际承受暂态负荷时具有明显的非线性,因此热散逸模型中必须考虑这一阻抗动态特性。基于ZnO电阻片非线性电热特性,建立暂态时变负荷下无间隙金属氧化物避雷器热散逸模型。首先研究ZnO电阻片在不同负荷与温度下阻抗特性变化规律,建立ZnO电阻片阻抗特性数学模型,然后将此数学模型代入热散逸计算模块,在暂态计算中不断将结果反代更新数学模型,实时根据即时温度结果调整模型阻抗参数。实验数据验证:暂态时变负荷避雷器热散逸模型计算结果能与实际较相符,在散热时间较长、散热时承担持续运行电压的情况下,考虑ZnO电阻片阻抗动态特性后避雷器温度曲线更精确。The impedance of ZnO varistor has dynamic characteristics when it is subjected to transient load,thus the dynamic characteristics should be considered in heat dissipating calculation.Based on the nonlinear electro-thermal characteristics of ZnO varistor,the heat dissipation model of the metallic oxide line arrester without gap(MOA)under transient time-varying load is established.Firstly,the change patterns of the ZnO varistor impedance under distinguished loads and temperatures are investigated so as to build a mathematical model of ZnO varistor impedance.Then,the model is substituted into the thermal dissipation calculation module.During the final time-dependent simulation progress,the real-time results are iterated back to the mathematical model,which means the material impedance parameters are adjusted in real time according to the temperature results.Experimental data verify that the calculation results of the heat dissipation model are in accordance with the actual situation.In the case of long heat dissipation time and heat dissipation under continuous operation voltage,the temperature curves of MOA are highly accurate after the dynamic characteristics of the ZnO resistor are taken into consideration.

关 键 词：热散逸 无间隙金属氧化物避雷器 ZNO电阻片 暂态时变负荷 电热耦合 有限元 

分 类 号：TM862[电气工程—高电压与绝缘技术]