张北柔性直流工程电压单环控制策略应用分析  

Application Analysis of Single-loop Voltage Control Strategy in Zhangbei Flexible DC Project of China

作　　者：马秀达 文继锋[1] 严伟[1] 卢宇[1] 汪楠楠[1] 邹强[1] 吕润东 王超[1] MA Xiuda;WEN Jifeng;YAN Wei;LU Yu;WANG Nannan;ZOU Qiang;LYU Rundong;WANG Chao(NR Electric Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]南京南瑞继保电气有限公司,江苏省南京市211102

出　　处：《电力系统自动化》2025年第2期198-207,共10页Automation of Electric Power Systems

基　　金：国家电网公司科技项目(荒漠地区大型新能源基地直流送出系统构建与综合评估技术研究,5100-202255354A-2-0-YS)。

摘　　要：在张北柔性直流工程调试和投运初期,送端孤岛换流站出现了多次600~3900 Hz频段的高频振荡现象。文中简述了采用双环控制策略的柔性直流换流站振荡机理,确定了高频振荡负阻尼来源于控制链路延时和电流控制环节。将电压单环控制策略应用于孤岛换流站,取消了电流控制环节,建立了考虑一次主电路动态过程和电压单环控制策略的柔性直流换流器阻抗数学模型,基于简化模型推导了电压单环控制的高频特征。采用直接限幅策略以实现快速准确暂态故障电流抑制,给出了控制切换判据以及暂态电流演变规律。所提出的控制策略在张北柔性直流工程得到了试验验证并实现长期稳定运行,解决了工程现场全工况高频振荡问题。At the initial stage of the commissioning and operation of Zhangbei flexible DC project of China,the high-frequency oscillation from 600 Hz to 3900 Hz in the converter station at the sending end occurred many times.This paper briefly describes the oscillation mechanism of the flexible DC converter station using the dual-loop control strategy and determines that the negative damping of high-frequency oscillation comes from the delay of the control link and the current control link.The single-loop control strategy is applied to the islanded converter station,and the current control link is eliminated.A mathematical model of the impedance of the flexible DC converter considering the dynamic process of the primary circuit and the single-loop control strategy is established.Based on the simplified model,the characteristic of single-loop voltage control in the high-frequency range is deduced.The direct amplitude limiting scheme is adopted to achieve fast and accurate suppression of the transient fault current,and the control switching criteria and transient current evolution laws are provided.The proposed control strategy has been validated through field tests and long-term stable operation in Zhangbei flexible DC project,which solves the problem of high-frequency oscillation under all operating conditions on the engineering site.

关 键 词：柔性直流输电 高频振荡 负阻尼 电流控制 电压控制 延时 直接限幅 

分 类 号：TM721.1[电气工程—电力系统及自动化]