摘要
同塔双回线路的每一回线路三相参数不对称及两回路之间的电磁耦合会导致三相不平衡,给电力系统设备带来诸多不利影响。准确计算同塔双回线路的不平衡度,分析其影响因素,对系统的安全运行具有重大意义。为此,针对宁夏北部电网在2006年网架和2007年网架下220 kV线路的不平衡电流过大的现象,采用ATP对环网进行建模,考虑共输电走廊中平行线路间的耦合作用和系统网架结构的影响,以实际潮流分布为基础对线路的不平衡电流进行仿真计算,得到了各种运行方式下的电流不平衡度,并与实测数据比较。仿真计算结果与实测数据基本相符,并表明通过在电站出线处合理调整同塔双回线路的相序排列,可有效改善宁夏北部电网220 kV线路的电流不平衡现象。
In double-circuit line on the same tower,three phases are unbalanced due to three-phase asymmetric parameters of each circuit and electromagnetic coupling between two circuits,which may endanger power equipment.Therefore,it is of great significance to calculate the unbalance degree and to analyze its influential factors of double-circuit transmission line.The unbalanced currents in Ningxia northern 220 kV power gird are large.Taking Ningxia northern 220 kV power gird as an example,we use ATP to build models for the ring network and to calculate the unbalanced currents of transmission lines based on practical power flow distribution,and compare the simulation results with measured data.The model includes the electromagnetic coupling between parallel lines and the topology of the ring network,which can simulate the real power grid effectively.The unbalanced currents under various operation conditions are obtained,consequently,the way to limit the current unbalance could be analyzed.The simulation results are in good agreement with the field data,and show that,by rationally adjusting the phase-order arrangement way of double-circuits transmission lines at the outlet of substation,the current unbalance in Ningxia northern 220 kV power grid can be effectively decreased.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2010年第2期488-494,共7页
High Voltage Engineering
关键词
220kV同塔双回线路
不平衡电流
相序排列
不平衡度
不换位线路
潮流
220 kV double circuit transmission line on the same tower unbalanced current phase-order arrangement unbalance degree untransposed transmission line power flow
