导体单丝表面处理对高压电缆载流量的影响研究

导体的集肤效应会影响导体的交流电阻,最终影响交流电缆的载流量,基于此,大截面导体通常采用分割导体的结构来降低交流电阻从而提高电缆的载流量。在此基础上对导体单丝表面进行绝缘处理也是降低导体交流电阻的手段之一,但IEC 60287标准中并未给出此类导体电缆的载流量计算方法。分别对220 kV电压等级导体单丝表面未处理的分割导体电缆和导体单丝表面绝缘处理过的分割导体电缆进行了空气中载流量测试,并参照IEC 60287考虑皱纹铝护套两侧空气间隙的影响,建立了220 kV电缆载流量计算方法。研究结果表明,载流量计算结果与试验结果偏差为0.74%,结果较为吻合。基于该方法对导体单丝表面处理后的分割导体的集肤效应系数进行了计算,文中所用导体单丝表面处理后分割导体的集肤效应计算所用因数ks为0.3。

Study on the Influence of Surface Preparation of Conductor Metal Wire on Current Rating of High Voltage Power Cable

The AC conductor resistance of high voltage cable will be influenced by skin effect,and the current rating of cable will accordingly be affected.Conductors with large cross sectional area are usually split to reduce power loss and increase the cable ampacity.In addition,the AC conductor resistance can also be reduced by insulating the sur face of single metal wires.However,the method to calculate the current rating of such kind of cable is not included in IEC 60287.In this paper,two 220 kV power cable with and without insulated conductor wire surfaces were tested for cable ampacity laid in air.The model to calculate cable current rating of 220 kV cable considering the air gaps adja cent to the corrugated aluminum sheath is established based on IEC 60287.The calculated ampacity accorded with ex perimental results with a deviation of 0.74%.The skin effect factor ks of split conductor with insulated conductor wire surface used in this research was calculated to be 0.3.