摘要
大规模新能源并网引发的次同步振荡严重威胁电力系统的安全稳定运行。为满足次同步振荡在线告警需求,需要分析宽频测量数据并快速提取振荡分量,快速检测到次同步振荡并精准切除振荡源已是迫切需要解决的关键技术。该文推导了对称和不对称三相电路中含有次同步频率电源时的瞬时功率表达式,揭示了瞬时功率主要为恒定功率分量和次同步频率的交变功率量;在此基础上,提出基于整周期瞬时功率差的次同步振荡频率提取方法,相比于快速傅里叶变换的计算速度大幅提升,避免了栅栏效应和频谱泄露问题;并提出了利用半周期瞬时功率差的次同步振荡源识别方法,可以对多风电场集中并网系统进行次同步振荡源定位,进而为精准切机提供支撑。时域仿真结果表明,该文提出的次同步振荡频率提取方法的计算速度相比快速傅里叶变换有显著提升,振荡源机组辨识方法具有较高的精度。
The subsynchronous oscillation has been a dynamic stability problem that threatens the safe and stable operation of power systems,and serious subsynchronous oscillation events have occurred frequently in recent years around the world.Therefore,it is important to promptly extracting the oscillation components and precisely remove the oscillation source by monitoring the wide-frequency measurement data online.Most of conventional subsynchronous component extraction methods,however,have sluggish calculation times and low calculation accuracy,making it challenging to meet the oscillation monitoring demands of a wide-frequency measurement system.To address these issues,this paper suggests a method of calculating instantaneous power using the voltage and current from the wide-frequency measurement system,realizing the extraction of the frequency of the subsynchronous oscillation and the identification of the oscillation source.Based on the instantaneous power from the measured data,the analytical formulas for the multimodal subsynchronous power of a doubly-fed induction generator grid-connected system were derived in this article.The major components of the subsynchronous power were extracted in the three-phase symmetric and asymmetric situations.Afterwards,using the features of the alternating power component in the main component of subsynchronous power,it was suggested to develop a frequency extraction method based on the whole-cycle instantaneous power difference.This method is faster and more accurate than the traditional method,avoiding the picket fence effect and spectrum leakage issues.Additionally,a method of the identification for subsynchronous oscillation source utilizing half-cycle instantaneous power difference was proposed based on the subsynchronous frequency extraction.This method can locate the subsynchronous oscillation source for the centralized grid-connected system of multiple wind farms and support for cutting machines.To validate the suggested method,a doubly-fed induction generator was simulate
作者
徐衍会
成蕴丹
刘慧
高镱滈
Xu Yanhui;Cheng Yundan;Liu Hui;Gao Yihao(School of Electrical and Electronic Engineering North China Electric Power University,Beijing 102206 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2023年第11期2894-2907,共14页
Transactions of China Electrotechnical Society
基金
国家重点研发计划资助项目(2021YFB2400800)。
关键词
风电场
次同步振荡
瞬时功率
振荡频率提取
振荡源识别
Wind farms
subsynchronous oscillation
instantaneous power
oscillation frequency extraction
oscillation source identification
