摘要
针对柔性直流输电工程中出现的中高频振荡问题,现有解决方法是在电压前馈通道中增设滤波器以抑制高频振荡,但增加了中频振荡的风险。以渝鄂柔直工程南通道单元为研究对象,提出了一种通过调整控制链路延时以避免中、高频振荡的方法。首先,基于多谐波线性化原理建立了MMC换流站阻抗模型,详细分析控制链路延时、电网电压前馈策略对MMC换流站阻抗特性以及对系统稳定性的影响;然后,探讨通过调整控制链路延时以避免中高频振荡的可行性,并给出了控制链路延时的选择方法;最后,通过PSCAD/EMTDC电磁暂态仿真验证了所提方法可实现渝侧、鄂侧系统中高频振荡抑制,同时对系统动态特性影响较小。
For the problem of medium and high frequency oscillations in flexible HVDC projects,the existing solution is to add a filter in the voltage feedforward path to suppress high frequency oscillations,which,however,increases the risk of medium frequency oscillations.For this reason,a method is proposed to avoid medium-high frequency oscillations by adjusting the control link delay based on the south channel of the Chongqing-Hubei flexible HVDC transmission project.Firstly,a impedance model of MMC converter station is established based on the principle of multi-harmonic linearization,and a comprehensive analysis is made on the influence of control link delay and grid voltage feedforward strategy on the impedance characteristics of MMC converter station and system stability.And then,the feasibility of adjusting the delay of the control link to avoid the medium-high frequency oscillation is discussed,and the method for selecting the time delay of the control link is given.Finally,based on PSCAD/EMTDC electromagnetic transient simulation,it is verified that the proposed method can achieve the suppression of the medium-high frequency oscillations in both the Hubei-side and Chongqing-side systems.Meanwhile,the proposed method has minor effect on the dynamic characteristics of the system.
作者
李奇南
夏勇军
张晓林
孙宝奎
孙华东
张帆
李兰芳
杨岳峰
韩情涛
LI Qinan;XIA Yongjun;ZHANG Xiaolin;SUN Baokui;SUN Huadong;ZHANG Fan;LI Lanfang;YANG Yuefeng;HAN Qingtao(NARI Group Corporation(State Grid Electric Power Research Institute),Nanjing 211006,China;Beijing DC Transmission and Distribution Engineering Technology Research Center(China-EPRI Electrical Engineering Co.,Ltd.),Beijing 102200,China;Electric Power Research Institute of State Grid Hubei Electric Power Co.,Ltd.,Wuhan 430061,China;China Electric Power Research Institute,Beijing 100192,China;China EPRI Science&Technology Co.,Ltd.,Beijing 102200,China;State Grid Hubei DC Inspection Company,Yichang 443001,China)
出处
《中国电力》
CSCD
北大核心
2022年第7期11-21,共11页
Electric Power
基金
国家电网有限公司科技项目(VSC/LCC直流并联混合多馈的近区电网动态功率协调控制研究,5100-202022011A-0-0-00)。
关键词
模块化多电平换流器
阻抗特性
中高频振荡
延时
柔性直流输电
modular multilevel converter(MMC)
impedance characteristic
medium-high frequency oscillation
time delay
flexible HVDC transmission