柔性低频输电系统两相运行特性分析  

Analysis of two-phase operation characteristics of a flexible low-frequency transmission system

作　　者：陆翌 华文 金玉琪 董玮 倪晓军 邹强[3] 吴小丹[3] LU Yi;HUA Wen;JIN Yuqi;DONG Wei;NI Xiaojun;ZOU Qiang;WU Xiaodan(State Grid Zhejiang Electric Power Co.,Ltd.Research Institute,Hangzhou 310014,China;State Grid Zhejiang Electric Power Co.,Ltd.,Hangzhou 310007,China;NR Electric Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]国网浙江省电力有限公司电力科学研究院,杭州310014 [2]国网浙江省电力有限公司,杭州310007 [3]南京南瑞继保电气有限公司,南京310027

出　　处：《浙江电力》2022年第12期98-105,共8页Zhejiang Electric Power

基　　金：国网浙江省电力有限公司科技项目(2021ZK06)。

摘　　要：针对基于M3C(模块化多电平矩阵式变换器)的柔性低频输电系统的两相运行方式,建立了低频系统复合序网,对常规控制策略下低频输电线路和M3C的稳态运行特性进行分析。分析表明,线路中将出现与正序电流等幅反相的零序电流,同时也会出现零序电压和负序电压;采用低频侧定功率控制和负序电流抑制策略的M3C子换流器间电容电压不均衡,M3C电容电压平均值存在2倍频振荡分量。在PSCAD/EMTDC中搭建双端型柔性低频输电系统仿真模型,验证了所得结论的正确性。The two-phase operation mode of a flexible low-frequency transmission system is based on the M3C(modular multilevel matrix converter).This paper establishes a complex sequence network for the low-frequency system to analyze the steady-state operation characteristics of low-frequency transmission lines and M3C under the conventional control strategy.The analysis shows that:(1)There appears zero-sequence current that shares equal am⁃plitude and opposite phase of the positive-sequence current in transmission lines;(2)The zero-sequence voltage and negative-sequence voltage can also appear in the transmission lines;(3)There is an unbalanced capacitor voltage be⁃tween M3C sub-converters with fixed power control on the low-frequency side and negative sequence current sup⁃pression strategy;(4)There is a double frequency oscillation component in the M3C average capacitor voltage.A simulation model of the dual-terminal flexible low-frequency transmission system is built in PSCAD/EMTDC,and the correctness of the obtained conclusions is verified.

关 键 词：柔性低频输电 两相运行 复合序网 

分 类 号：TM732[电气工程—电力系统及自动化]