摘要
同杆并架平行双回线路并列运行存在三相不平衡电流,而解列运行时不存在。通过直接去耦法分析了三相不平衡电流的产生机理。利用直接去耦法分别建立了双回线路解列运行和并列运行时的正序等值电路和零序等值电路。分析发现双回线并列运行时,两回线的正序电流和零序电流分别相互并联,但由于线路三相参数不对称,正序电流分布系数与零序电流分布系数不同,导致双回线间出现环流,进而使得双回线三相电流不平衡。以云南临沧电网110kV新云ⅠⅡ回线为例,建立了仿真模型,利用ATP-EMTP进行了双回线并列运行和解列运行的仿真,结果表明分析结论正确。
Parallel operation of parallel double circuit lines on the same tower has three-phase unbalanced currents, but does not exist in disconnection operation. The generation mechanism for the three-phase unbalanced current is analyzed by a direct decoupling method. The direct decoupling method is used to establish the positive sequence equivalent circuit and zero sequence equivalent circuit for double circuit line when it is in disconnection and parallel operation. It is found that the positive sequence current and zero sequence current of the double lines are paralleling in parallel operation. However, the positive sequence current distribution coefficient and the zero sequence current distribution coefficient are different due to the unbalance three-phase parameters, leading to the circulation between the double lines and making the three phase current of the unbalanced double line. Taking the 110 kV Xinyun Ⅰ-Ⅱ double line of the Yunnan Lincang power grid as an example, the simulation model is set up. The simulation of the parallel and disconnection operation of the double line is carried out by ATP-EMTP. Results show that the conclusion is correct.
作者
杨金东
陶晔
李周龙
吴思奇
郭鹏程
YANG Jindong;TAO Ye;LI Zhoulong;WU Siqi;GUO Pengcheng(Lincang Power Supply Bureau, Lincang 677000, China;Institute of Water Resources and Hydro-electricEngineering, Xi’an University of Technology, Xi’an 710048, China)
出处
《西安理工大学学报》
CAS
北大核心
2019年第3期368-372,共5页
Journal of Xi'an University of Technology
基金
国家自然科学基金资助项目(51479166)
关键词
同杆并架平行双回线路
三相不平衡电流
环流
并列运行
解列运行
double-circuit transmission lines on same tower
three phase unbalanced current
circulating current
parallel operation
disconnection operation
