MMC对交流系统三相短路故障短路电流影响的机理研究

发布时间：2018-11-04 13:19

【摘要】：该文从柔性直流输电系统运行控制原理出发,分析得到柔性直流电网换流站近区发生三相短路故障后,换流站提供短路电流的特征,并在PSCAD上搭建模型进行仿真验证。研究发现,短路故障发生后,柔性直流换流站呈电流源特性,提供的短路电流分为暂态过程和稳态过程两个阶段。故障发生控制系统响应后,换流站提供的短路电流是三相对称交流量,不存在直流分量。短路电流暂态过程与换流站的控制参数有关,而短路电流稳态值的大小与换流站的控制方式、运行模式以及换流站控制器的控制参数密切相关。该研究可以为今后柔性直流输电工程建设中控制参数的设定,以及柔性直流输电工程换流站接入点的选择提供参考。
[Abstract]:Based on the operation control principle of flexible DC transmission system, this paper analyzes the characteristics of short circuit current provided by converter station after three-phase short circuit fault occurs in the near area of the converter station of flexible DC network, and builds a model on PSCAD for simulation verification. It is found that after the short-circuit fault occurs, the flexible DC converter station has the characteristics of current source, and the short-circuit current can be divided into two stages: transient process and steady state process. After the response of the fault generation control system, the short circuit current provided by the converter station is three phase symmetric AC, and there is no DC component. The transient process of short-circuit current is related to the control parameters of the converter station, while the value of the steady-state value of the short-circuit current is closely related to the control mode, operation mode and control parameters of the converter station controller. This study can provide a reference for the design of control parameters in the construction of flexible DC transmission project in the future and the selection of the access point of the converter station in the flexible direct current transmission project.
【作者单位】：中国电力科学研究院;
【基金】：国家电网公司科技项目《±500k V柔性直流电网运行特性与控制技术研究》国家重点研发计划(2016YFB0900600)~~
【分类号】：TM721.1

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