10 kV交流三芯电缆中间接头直流化改造热-电耦合仿真研究

将交流电缆改为直流运行后,对电缆接头进行温度场和电场仿真并研究其温度和场强分布规律对改造后的电缆供电能力的评估非常重要,目前关于交流电缆直流化改造的研究主要是针对电缆本体,对电缆接头的研究还较少。本文建立了城市配电网中常见的10 kV交流三芯电缆接头的三维仿真模型,首先采用ANSYS中的热-电耦合模块对接触系数k=4时的接头模型进行温度场仿真;之后研究了接触电阻和空气对流换热系数对接头温度分布的影响;最后进行了电缆接头直流运行时的电场仿真,并根据温度场和电场仿真结果选取了直流载流量和合适的直流运行电压,与接头交流运行时进行了传输最大功率的比较。研究结果表明,交流电缆接头直流化改造后功率传输能力有了一定的提升。

Study on the Thermal-Electric Couple Simulation of DC Transformation for 10 kV AC Three-Core Cable Joint

After the transformation of AC cable into DC operation,it is very important to conduct temperature and electric field simulation on the power cable joint and study its temperature distribution and electric field intensity to accurately evaluate the power supply capacity.At present,researches on the DC transformation of AC cable almost focuse on the cable body,and there are few researches on the cable joint.In this paper,the 3D simulation model of 10 kV three-core cable joint which is commonly used in the urban distribution network is established,first,the ANSYS heat-electricity coupling module is used to simulate temperature field of previous statement 3D model in which the contact resistance coefficient is four and the temperature distribution is analyzed.Then,the influences of contact resistance,and air convective heat transfer coefficients on cable joint temperature are studied.At last,the DC electric simulation of cable joint is conducted,and choose the DC current capacity and suitable DC voltage according to the temperature and electric simulation,the maximum transmission power is compared with AC cable joint.The results show that the power transmission capacity of AC cable joint is improved after the DC transformation.