1000kV交流单回紧凑型输电线路电磁环境研究

Electromagnetic Environment of 1000kV AC Single-circuit Compact Transmission Lines

紧凑型输电线路可较大幅度提高自然输送功率,有效压缩输电线路走廊宽度,提高单位走廊利用率,是今后我国特高压输电技术发展的方向之一。为此,对特高压单回紧凑型输电线路导线等边倒三角布置的电磁环境进行了全面研究,综合考虑电气、导线次档距振荡两方面特性和线路经济性等因素,确定了7种较优的导线结构及其分裂间距。建议特高压紧凑型采用与特高压常规线路相同的控制指标,计算了不同导线结构的工频电场、磁感应强度、可听噪声和无线电干扰水平,获得了满足电磁环境要求的导线结构和相间距离,通过比较线路损耗和自然功率等指标确定了10×500与12×400两种较优的导线布置方案,并与特高压常规单、双回线路进行了比较。研究表明特高压紧凑型线路采用10×500导线、相间距离14.9 m时其自然功率较常规单回路典型布置可增加约26%,同时可大幅减小输电走廊,单位走廊输送容量为后者的2.80倍。

Compact transmission lines can greatly enhance the natural power, and effectively reduce the corridor ot power lines to increase the utilization of corridor unit. We investigated the electromagnetic environment of 1000kV AC single-circuit compact transmission lines with inverted equilateral triangle conductors arrangement. Seven kinds of conductor arrangement with its corresponding bundle spacing were decided by the consideration of electric charac- teristics, sub-span oscillation characteristics, and economy. Then the power frequency electric field strength, the magnetic field strength, the audible noise, and radio interference of different conductor structures were cal.eulated, assuming that the UHV compact transmission lines and the conventional lines had the same control indexes~ and the conductor structure and bundle spacing were acquired. Therefore, the conductor arrangements of 10 ）〈 500 and 12 ~ 400 were determined. Moreover, the conventional lines of single-clrcult and double-circuit were compared. By con- trast with the sing）e-circuit conventional lines, the natural power of compact UHV transmission lines could increase by about 26%, and the transmission capacity of unit corridor is 2.80 times, which significantly reduces the corridor.