摘要
近期,某实际新能源经柔直送出系统出现了40~60 Hz的近工频正序和负序振荡现象,导致新能源降出力运行。新能源经柔直送出系统的近工频振荡较其他频段振荡的机理更为复杂,影响因素更多。针对直驱风电场经柔直送出系统近工频振荡稳定性问题,建立了含正/负序控制的直驱风电机组和柔直送端模块化多电平换流器(modular multilevel converter,MMC)的精细化阻抗模型,从阻抗特性角度揭示了直驱风电场经柔直送出系统产生近工频正/负序振荡的机理;定义了参数相位裕度灵敏度,量化分析了直驱风电场柔直送出系统近工频振荡稳定性的关键影响因素。最后,搭建直驱风电场经柔直送出系统的电磁暂态仿真模型,仿真复现了实际系统的近工频正序和负序振荡现象,并验证了近工频振荡机理分析的正确性。
Positive-and negative-sequence oscillation phenomena close to the fundamental frequency(40-60 Hz)occur in a practical modular multilevel converter-based high-voltage DC(MMC-HVDC)transmission system for new energy integration,which has led to a decrease in the power output of new energy sources.The mechanism of near-fundamentalfrequency oscillations is more complex and has more influencing factors than oscillations in other frequency bands.This study focuses on the near-fundamental-frequency oscillation stability of an MMC-HVDC-connected direct-drive wind farm.Refined impedance models of the direct-drive wind turbine and sending-end MMC are established by considering positive and negative sequence controls.Based on the established impedance models,the mechanisms of the near-fundamental-frequency positive-and negative-sequence oscillations between the direct-drive wind farm and the sending-end MMC are revealed.In addition,the parameter phase-margin sensitivity is defined,and the key influencing factors of the near-fundamentalfrequency oscillation stability of the interconnected system were analyzed quantitatively.Finally,an electromagnetic transient simulation model of the MMC-HVDC-connected direct-drive wind farm is developed.The near-fundamental-frequency positive-and negative-sequence oscillation phenomena in the actual project are reproduced,and the correctness of the nearfundamental-frequency oscillation mechanism analysis is validated.
作者
于婧
林鸿飞
王潇
吕敬
吴林林
李蕴红
YU Jing;LIN Hongfei;WANG Xiao;LÜJing;WU Linlin;LI Yunhong(National Power Dispatching and Control Center,State Grid Corporation of China,Beijing 100052,China;Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education(Shanghai Jiao Tong University),Shanghai 200240,China;State Grid Jibei Electric Power Co.,Ltd.Research Institute,Beijing 100045,China)
出处
《电力建设》
CSCD
北大核心
2024年第2期10-25,共16页
Electric Power Construction
基金
国家自然科学基金项目(52277195)
华北电力科学研究院有限责任公司资助项目(KJZ2022056)。
关键词
风电场
柔性直流输电
近工频振荡
负序控制
负序振荡
灵敏度
wind farm
flexible DC transmission
near-fundamental-frequency oscillation
negative-sequence control
negative-sequence oscillation
sensitivity
