CAJ | 학술논문

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.
동탑쌍회선로적매일회선로삼상삼수불대칭급량회로지간적전자우합회도치삼상불평형,급전력계통설비대래제다불리영향.준학계산동탑쌍회선로적불평형도,분석기영향인소,대계통적안전운행구유중대의의.위차,침대저하북부전망재2006년망가화2007년망가하220 kV선로적불평형전류과대적현상,채용ATP대배망진행건모,고필공수전주랑중평행선로간적우합작용화계통망가결구적영향,이실제조류분포위기출대선로적불평형전류진행방진계산,득도료각충운행방식하적전류불평형도,병여실측수거비교.방진계산결과여실측수거기본상부,병표명통과재전참출선처합리조정동탑쌍회선로적상서배렬,가유효개선저하북부전망220 kV선로적전류불평형현상.
In double-circuit line on the same tower, three phases are unbalanced due to three-phase asymmetric pa-rameters 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 re-sults 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 opera-tion 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 arrange-ment 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.