牛从直流方式转换时中性母线过电压抑制  

Neural Bus Over-voltage Suppression in DC Mode Conversion at Niucong

作　　者：代书龙 张锐[1] Dai Shulong;Zhang Rui(Qujing Bureau,China Southern Power Grid EHV Power Transmission Co.,Qujing Yunnan 655000,China)

机构地区：[1]中国南方电网超高压输电公司曲靖局,云南曲靖655000

出　　处：《电气自动化》2020年第5期69-71,共3页Electrical Automation

摘　　要：为抑制牛从直流运行方式发生转换时牛寨站中性母线过电压,提高直流系统可靠性,根据牛从直流输电系统参数以及运行方式转换控制逻辑,搭建牛从直流PSCAD/EMTDC仿真模型。通过仿真分析了牛从直流方式转换过程中,牛寨站中性母线区域产生过电压的原因为转换瞬间产生的低次谐波电流流过接地极线路,谐波电流在接地极线路等效电感两端产生过电压。直流系统开展金属/大地回线方式转换过程中,转换瞬间在牛寨站中性母线区域投入并联电容可大大降低中性母线区域电压以及接地极线路谐波电流,通过仿真验证了所提措施的有效性。In order to suppress neutral bus over-voltage in Niucong DC operation conversion at Niuzhai Station to raise DC system reliability,a Niucong DC PSCAD/EMTDC simulation model was established according to the parameters and operation mode switchover control logic of the Niucong DC transmission system.Simulation analysis revealed that over-voltage occurring in the neutral bus area of Niuzhai Station in the process of Niucong DC mode conversion was attributable to the low-order harmonic current generated at the instant of conversion flowing through the grounding electrode line,and the harmonic current generated over-voltage at both ends of the equivalent inductors of the grounding electrode line.In the process of conversion of metal/earth return in the DC system,adding shunt capacitors to the neutral bus area of Niuzhai Station at the instant of conversion could substantially reduce the voltage of the neutral bus area and the harmonic current of the grounding electrode line.The effectiveness of the proposed measure was verified through simulation.

关 键 词：牛从直流 中性母线 过电压 PSCAD/EMTDC仿真 并联电容 

分 类 号：TM743[电气工程—电力系统及自动化]