10 kV与110 kV电缆线路混合敷设对环流影响研究

Research on impact of mixed laying of 10 kV and 110 kV cable line on circulating current

近年来,随着城市不同等级地下多回路电缆线路敷设的增多,其多回路造成的电缆金属护套环流损耗问题也趋于严重。基于电磁感应原理,计算了10、110 kV单芯电缆线路金属护套交叉互联时护套感应电压,并通过建立电缆线路阻抗模型推导环流矩阵方程,获得了不同电压等级线路中金属护套环流及相互影响。结果表明,混合敷设会造成10 kV线路环流增加和110 kV线路环流的减小;10、110 kV线路相间距增大会增加自身环流但相互影响却不同,110 kV线路相间距增大200 mm,10 kV线路环流增加48.99%,10 kV线路相间距增大200 mm,110 kV线路环流几乎不会发生变化;10、110 kV线路交叉互联单元内三段电缆段长改变会影响自身环流,但不会影响临近线路;负载电流增加均会极大影响环流;不同电压等级回路垂直距离越大,环流越小;环流最大相序组合为BAC-CAB(10～110 kV),最小环流相序为CBA-ACB(10～110 kV)。以上分析结果对电缆线路规划和设计提供了理论支持和数据支撑。

In recent years,more and more multi-circuit cable lines of different voltage levels are laid underground of the cities,multi-circuit can cause the problems of circulation loss on cable metal sheath become severe,the different voltage levels of the cable lines are mixed laid,which have a greater impact on circulating current.Based on the principle of electromagnetic induction,calculating the induced voltage of 10,110kV single core cables in this paper,both of sheaths with applied cross-bonding connection.Circulating current matrix equation is figured out by the impedance model,and finally get the result of circulating current on the metal sheath of different voltage cable lines and the interdependent of each other.The results show that mixed-laying will lead the 10,110kV line circulating current increase and decrease;10,110kV line’s circulating current will increase with the increasing of space between different phases,but interaction between them is different,10kV line circulating current increased by 48.99%when 110kV line phase spacing increased 200 mm,10kV line phase spacing increased 200 mm,the 110kV line circulating current almost did not change;the arrange of three segments length of cable on cross-bonding unit will affect their own circulating current,but does not impact the circuit which next to;the varies of load current influence circulating current greatly;The greater the vertical distance between the 10,110kV line,the smaller the circulating current is;the circulating current is the largest as the phase sequence is BAC-CAB(10~110kV),the smallest circulating current appears when the phase sequence is CBA-ACB(10~110kV).The results above will have good reference for cable route planning and design.