老化状态下矿用XLPE电缆容量和温升的20130728.docx

矿用XLPE电缆老化状态对载流量和温升的影响李海英1，吕建华1，刘毅超1，宋建成2（1．上海理工大学电气工程系，上海市杨浦区 200093；2．太原理工大学电气与动力工程学院，山西省太原市 030024）摘要：矿用XLPE电缆老化程度的不断加重，会不同程度地影响到其额定运行参数。通过分析电缆绝缘参量的温度效应和老化特征，明确运行中矿用高压电缆的介质损耗不可忽略，并据此建立了老化对在役矿用XLPE电缆载流量和温升影响的评估理论。定义额定容量降低因子，定量描述介质损耗导致的电缆载流量降低，并修订鉴幅式电流保护动作值。根据单芯电缆温升计算式，提出了兼顾老化因素的三芯电缆温升解析式，进行稳态温升预测。基于导体损耗的温度正相关性，利用ANSYS有限元仿真软件，建立热电耦合迭代模型来确认理论模型，并对电缆温升和载流能力进行仿真计算。算例对比分析了老化电缆水树附近和老化电缆整体的温升以及载流能力，为实际运行中电缆的状态监测和故障保护提供参考依据。关键词：矿用XLPE电缆；老化；温升；额定容量降低因子；介质损耗；热电耦合文章编号：中图分类号：TM 247 文献标识码：A 学科分类号：470.40Impacton Ampacity and Temperature of mining XLPE cable under aging conditionLI Haiying1, LV Jianhua1, LIU Yichao1, SONG Jiancheng2(1. Department of Electrical Engineering, University of Shanghai for Science and Technology, Yangpu District, Shanghai 200093, China; 2. College of Electrical and Power Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi Province, China)Abstract:With the further aging of mining XLPE cable, the defaultrated parameters need adjusting accordingly. Based on the analysis of temperature effect and aging characteristics of cable insulation parameters,it can be concluded that the dielectric loss of high voltage mining cable should not be neglected, and thereforean assessment theory for the ampacity and temperature rise of the mining XLPE cable in service considering the aging factor is established.The derating factoris defined to quantify the ampacity reduction in the present of aging phenomenon, and the value to trigger the current protection is reset. The procedure to calculate the temperature rise of the three-core cable involving the aging factor is put forward by extending the single-core cable model to handle such problems. In addition, an XLPE cable thermal-electromagnetic coupling model due to the power loss’s dependence on the temperature is built by the ANSYS finite-element analysis software.The model is adopted to test the validity of the analytic procedures, and simultaneously simulate the temperatureandampacity of mining X