XLPE电缆磁热耦合分析.docVIP

摘 要 大量非线性工业负载在矿井配电网中的高度渗透使电力谐波对电缆的影响不可忽略。谐波会使电缆产生额外的功率损耗，继而引起温升，影响电缆的正常工作。矿用XLPE电缆作为矿井配电系统的重要组成，探讨谐波对其容量和稳态温度的影响对矿井安全运行具有重要意义。 第一章绪论介绍了课题的研究意义、电缆的发展历史、国内外研究现状和ANSYS软件简介。 第二章介绍了电力电缆的历史、结构、分类、XLPE电缆的优势以及谐波理论、产生原因和危害。 第三章通过分析谐波引发的附加功率损耗，建立了谐波对矿用高压XLPE电缆容量和稳态温度影响的评估方法。定义额定容量降低因子，定量描述谐波引发的额外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，给出了兼顾谐波电流的三芯电缆温升解析式，进行稳态温升预测。 第四章具体介绍了ANSYS软件，主要是ANSYS在电磁场、温度场和耦合场的应用，并对电磁场和温度场的理论知识做了说明。 第五章用ANSYS软件做了单芯电缆和三芯电缆的仿真，利用ANSYS有限元仿真软件，建立磁热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，得出单芯电缆和三芯电缆在无谐波环境下和谐波环境下的温度分布图，并将结果和理论值进行对比分析。算例结果表明该研究为谐波环境下电缆的设计、选型、监测和保护提供有效决策依据。 第六章总结所做的工作，提出还存在的不足和问题，并对课题做展望。 关键词：矿用XLPE电缆 谐波 温升 功率损耗 磁热耦合 ABSTRACT With the high penetration of the non-linear industry loads into the mine distribution systems, the harmonic influence on the cable must be taken into account. The harmonic will increase additional power loss and thus causing the temperature rise and affecting the normal operation of power cable. Mining XLPE power cable is an important part of mining distribution system, so it’s important to discuss the influence of harmonic to its capability and stable temperature. The first chapter introduces the importance of this topic, the history of the cable, research status and ANSYS software description. The second chapter describes the history, structure, classification of power cable and the advantage of XLPE cable as well as harmonic theory, causes and hazards. In the third chapter, based on the additional power loss caused by the harmonic current, an assessment method for capacity and steady temperature of the mining high-voltage XLPE cable including harmonics is established. The equivalent transmission capacity is defined to quantify the capacity reduction in the presence of harmonics, and the value to trigger the current protection is reset. The procedure to calculate the steady temperature of the three-core cable involving the harmonics is put forward by extending the single-core cable model to handle such problems. The fourth