【作者】 刘连光； 闫旭东； 马成廉； 魏恺； 张燕秉；

【Author】 LIU Lian-Guang;YAN Xu-Dong;MA Cheng-Lian;WEI Kai;ZHANG Yan-Bing;School of Electrical and Electronic Engineering North China Electric Power University;State Grid DC Project Construction Branch Company;

【机构】 华北电力大学电气与电子工程学院； 国家电网公司直流建设分公司；

【摘要】 溪洛渡-浙西±800k V直流输电投运发现了严重的换流变直流偏磁问题,目前国内外未见高压直流输电(HVDC)换流变编组及受端电网结构对换流变直流偏磁影响的研究报道。针对溪洛渡-浙西UHVDC受端电网结构和浙西站4组换流变及其运行方式,建立了考虑换流变编组运行方式和受端电网等影响因素的直流偏磁电流计算模型,运用比较分析法和节点电压法计算了换流变的直流偏磁电流,研究了换流变编组和受端电网结构对换流变直流偏磁的影响。结果表明,当1/2单极大地满负荷运行时换流变的直流偏磁最严重,换流站500k V母线馈线长度、回路数及与接地极的距离是影响换流变直流偏磁严重程度的主要因素。研究工作及成果对电网规划与设计中制定换流变直流偏磁抑制策略具有重要意义。更多还原

【Abstract】 During the operation of Xiluodu-Zhexi ±800 k V HVDC transmission project, a serious DC bias problem arose for converter transformers. Currently, there is still no research report on the effect of converter transformer marshalling and receiving-end grid structure on converter transformer DC bias in HVDC both domestically and abroad. Based on Xiluodu-Zhexi UHVDC receiving-end grid structure and four groups of converter transformer of Zhexi converter station and their operation mode, we established a calculation model for DC bias current, taking into consideration factors such as the converter transformer marshalling operation mode and the receiving-end grid. Using comparative analysis and node voltage method, the converter transformer DC bias current is calculated, the influence of different converter transformer marshalling and receiving-end grid structures on converter transformer DC bias is analyzed. The results showed that, the most severe DC bias occurs in converter transformers when the converter is operating at 1/2 unipolar ground at its full capacity, and the main factors affecting DC bias severity are the length of the 500 k V bus feeder, its loops number and its distance to the grounding electrode. The research and achievements are significant for the development of the converter transformer DC bias suppression strategy during network planning and design.更多还原