摘要
直流电压是衡量真双极多端柔性直流输电(VSC-MTDC)系统安全稳定运行的重要指标。针对传统换流站直流电压下垂系数固定而未考虑实际运行工况导致的直流电压偏差较大这一问题,文中以传统直流电压下垂控制为基础,提出一种考虑功率裕度与电压运行参考点的自适应直流电压下垂控制方法。通过构建功率裕度系数HP来实现下垂系数的实时变化;通过分析HP大小对下垂控制的影响,引入直流电压影响权重μ调整下垂控制参考电压运行工作点,保障HP过小时直流电压偏差不越限。基于PSCAD/EMTDC搭建大规模新能源接入的四端真双极VSC-MTDC系统,在稳态、风电场功率波动、换流器单极闭锁运行工况下进行仿真,验证直流电压的稳定性和功率分配的合理性。文中研究可为进一步提高真双极VSC-MTDC系统控制的安全稳定运行提供参考。
The DC voltage is an important index to measure the safe and stable operation of true bipolar voltage source converter multi-terminal DC(VSC-MTDC)system.In allusion to the problem that the DC voltage sag coefficient of the traditional converter station is fixed without considering the large DC voltage deviation caused by the actual operating conditions,an adaptive DC voltage sag control method that considers power margin and voltage operation reference points is proposed based on the traditional DC voltage sag control.The power margin coefficient HP is constructed to realize the real-time change of the sag coefficient.By analyzing the influence of the HP magnitude on the sag control,the DC voltage influence weightμis introduced to adjust the reference voltage operating point of the sag control,so as to ensure that the DC voltage deviation does not exceed the limit when HP is too small.A four-terminal true bipolar VSC-MTDC system with large-scale new energy access is built based on PSCAD/EMTDC.The stability of DC voltage and the rationality of power allocation were verified by the simulation under steady state,wind farm power fluctuation and converter unipolar locking operation conditions.It can provide a reference for further improving the control safety and stable operation of true bipolar VSC-MTDC system.
作者
彭寅章
王海云
南东亮
肖超
杨帅
PENG Yinzhang;WANG Haiyun;NAN Dongliang;XIAO Chao;YANG Shuai(MOE Research Center of Renewable Energy Power Generation and Grid Connection Control Engineering,Xinjiang University,Urumqi 830047,China;Electric Power Research Institute,State Grid Xinjiang Electric Power Co.,Ltd.,Urumqi 830013,China;Electric Power Research Institute,State Grid Henan Electric Power Co.,Ltd.,Zhengzhou 450052,China)
出处
《现代电子技术》
2023年第16期128-134,共7页
Modern Electronics Technique
基金
国家重点研发计划项目(2021YFB1507005)
新疆维吾尔自治区重点研发计划项目(2020B02001)。
