±500 kV直流输电工程同杆并架技术的综合研究

Comprehensive Study on Technology of Two Bipole Lines on the Same Tower for±500 kV HVDC Project

同杆并架输电技术用于长距离高压直流输电工程在国内外尚无先例,在葛南直流综合改造工程中,如应用同杆并架技术将原葛南1回1200 MW直流系统改造成2回3 000 MW直流系统,其输电能力将达到现有直流输电系统的5倍,但也会遇到各种新的技术问题。从直流线路杆塔参数的选择、雷电特性、电磁环境及同杆并架直流系统间的相互影响、可靠性等方面对该方案进行了深入的分析。分析结果已被应用于研究葛南直流增容工程的可行性。

There is no precedents of applying two bipole lines on same tower technology in long-distance HVDC transmission project home and abroad. If the technology of two bipole lines on same tower could be applied to the renovation project aiming at increasing transmission capacity of existing ±500kV HVDC from Gezhouba to Nanqiao, the transmission capacity of 1200 MW by existing one bipole line would be changed into 2×3000MW by two bipole lines on same tower, namely after the renovation the transmission capacity would be increased by four times, however, several new technical matters will be met in such a renovation. The authors analyze the proposed project in detail in following aspects： the parameter selection of towers for DC transmission line, lightning characteristics, reliability, electromagnetic environment and mutual influence between the DC lines on the same tower. These analysis results are already applied in the feasibility research of the project to increase transmission capacity of existing HVDC from Gezhouba to Nanqiao.