多端柔性直流输电中换流站的同步切换控制策略  

Synchronous Switching Control Strategy for VSC Station in MTDC Network

作　　者：付强[1] 杜文娟[1] 王海风[1] 郑凯元 FU Qiang, DU Wenjuan, WANG Haifeng, ZHENG Kaiyuan(School of Electrical and Electronic Engineering, North China Electric Power University, Changping District, Beijing 102206, Chin)

机构地区：[1]华北电力大学电气与电子工程学院

出　　处：《电网技术》2018年第4期1241-1250,共10页Power System Technology

基　　金：国家电网公司科技项目(SGZJ0000BGJS1500265)~~

摘　　要：功率同步控制和矢量控制均是多端柔性直流输电系统（multi-terminal voltage source converter based high voltage direct current transmission,VSC-MTDC）中换流站的可选控制方式。与更加常用的矢量控制方式相比,功率同步控制方式的原理与同步发电机类似,进而显现了相近的控制特性,更适用于与交流电网的弱连接,有利于交流电网的功角和频率稳定性,但其缺点是在直流侧故障下,换流站会出现较大的直流电压波动,恶化系统的动态特性。为了使换流站能够在不同的电网运行工况下匹配最合适的控制方式,提出一种可切换的控制策略,实现了在同一换流站中功率同步和矢量控制方式并存,并可依据需求实现无扰动自动切换。最后以PSCAD中搭建的三端交直流系统为例,演示和验证了同步切换控制策略的可行性。Power synchronization control and vector control are two optional control strategies for VSC station in MTDC network. Power synchronization control is more suitable to connect a weak ac system, showing similar dynamic characteristics to generator and possibly positive for angle and frequency stability of AC systems, compared with vector control. But for DC side fault, VSC station utilizing power synchronization control will appear huge DC voltage fluctuation. In order to match the most suitable control method under different operation modes of power system, a synchronous switching control strategy is proposed in this paper. This control strategy makes two control strategies coexist in one VSC station, realizing switching to vector control from power synchronization control to reduce DC voltage fluctuation under DC fault. Simulation results of three-terminal AC/DC transmission systems in PSCAD show that this control strategy can achieve undisturbed switching and improve stability of AC/DC transmission system under different faults.

关 键 词：VSC-MTDC 矢量控制方式 功率同步控制方式 同步切换控制策略 

分 类 号：TM721[电气工程—电力系统及自动化]