共走廊同塔交直流输电线路电磁耦合分量的计算分析

为了充分利用架空线路走廊,交直流同塔输电将是电网未来发展的趋势,开展同塔交直流线路间电磁耦合干扰研究具有重要意义。利用电磁暂态仿真软件PSCAD/EMTDC建立了双回交流与单回直流同塔输电线路耦合模型,研究了交流线路不同排列方式、导线相序和运行状态对直流线路电磁耦合的影响,计算了耦合地线以及耦合地线根数变化对直流线路电磁耦合的屏蔽效果。研究结果表明:交流线路呈倒三角且相导线采用ABC/ACB相序排列时,直流线路上的电磁耦合分量较小;交流线路故障严重破坏了电气参数的平衡,导致直流线路电磁耦合分量变大;耦合地线根数越多,屏蔽效果越好,耦合地线根数达到一定数量时,屏蔽效果将趋于饱和。

Calculation and Analysis on Electromagnetic Coupling Component of AC/DC Transmission Lines on the Same Tower Built in Same Corridor

To make full use of the overhead line corridor, development of AC/DC transmission lines on the same tower will be a future trend for power grid. It is therefore of great significance to study the electromagnetic coupling interference of AC/DC transmission lines on the same tower. The coupling model of double-circuit AC and single-circuit DC transmission lines was established based on PSCAD/EMTDC in this paper. The results show that the electromagnetic coupling component of DC lines are smaller when AC lines are arranged in inverted triangle and the phase conductors are arranged in ABC/ACB. The balance of electrical parameters are severely damaged by AC lines fault, leading to the increasing of electromagnetic coupling component of DC lines. The more the coupling ground wires are, the better the shielding effect is. The shielding effect tends to saturation when the number of coupling ground wires reaches a certain number.