基于动态谱线插值的新能源场站同步基准信号检测方法  

Synchronous Reference Signal Detection Based on Dynamic Spectral Line Interpolation for Renewable Energy Station

作　　者：施志明 董玮 张军军 吴福保 SHI Zhiming;DONG Wei;ZHANG Junjun;WU Fubao(State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems(China Electric Power Research Institute),Haidian District,Beijing 100192,China;School of Electrical Engineering and Automation,Hefei University of Technology,Hefei 230009,Anhui Province,China)

机构地区：[1]新能源与储能运行控制国家重点实验室(中国电力科学研究院有限公司),北京市海淀区100192 [2]合肥工业大学电气与自动化工程学院,安徽省合肥市230009

出　　处：《电网技术》2024年第1期229-237,共9页Power System Technology

基　　金：海南省重点科技计划项目(ZDKJ2020013)。

摘　　要：在含高比例新能源的低惯量电力系统中,系统频率呈现基频偏移严重、频率变化快等特征,导致新能源场站在进行并网测试及支撑性能评估时,同步基准信号检测误差增大,进而可能威胁到系统的安全稳定运行。对此,提出基于动态双离散傅里叶变换类(discrete Fourier transformation,DFT)谱线插值的同步基准信号检测算法。通过分析低惯量电力系统受功率扰动后的频率动态响应,揭示系统中基频静动态特征,并在此基础上建立静动态电网信号分析模型。进而量化基频偏移场景下的传统DFT谐波检测算法误差,并说明谱线插值类DFT算法在动态基频场景下的失效机理。继而利用希尔波特黄变换(Hibert-Huang transform,HHT)算法识别动态基频,并结合双DFT谱线插值法修正基频及谐波信号幅值,提高检测精度。又为改善检测效率,增设算法选择判据。试验测试结果表明:所提的检测算法能够准确的测量出强动态电网信号中的基准量,提高对新能源场站同步支撑、电能质量等并网性能的评估精度,为新能源高占比电力系统的同步基准信号检测提供新的可选方案。In the low-inertia power system with a high proportion of renewable energy sources,the frequency of the system is characterized by serious fundamental frequency excursions and rapid frequency changes,which leads to the increase of the synchronous benchmark signal detection errors in the grid-connected tests and the support performance evaluations of the new energy stations,threatening the safe and stable operation of the system.A synchronous reference signal detection algorithm based on the dynamic double DFT spectral line interpolation is proposed.By analyzing the frequency dynamic response of the low inertia power system after the power disturbance,the static and dynamic characteristics of the fundamental frequency are revealed,and on this basis,the static and dynamic power grid signal analysis model is established.Then,the error of the traditional DFT harmonic detection algorithm is quantified in the fundamental frequency offset scenario,and the failure mechanism of the spectral line interpolation DFT algorithm in the dynamic fundamental frequency scenario is illustrated.The HHT algorithm is further used to identify the dynamic fundamental frequency,and combined with the double DFT spectral line interpolation method the amplitudes of the fundamental frequency and harmonic signals are corrected so as to improve the detection accuracy.In order to improve the detection efficiency,an algorithm selection criterion is also added.The test results show that the detection algorithm proposed in this paper is able to accurately measure the reference quantity in the strong dynamic grid signals.It improves the evaluation accuracy of the grid connection performance,such as the synchronous support of the new energy stations and the power quality.Moreover it provides a new alternative scheme for the synchronous reference signal detection in the power systems with a high proportion of renewable energy.

关 键 词：基频偏移 频率变化率 基准信号检测 低惯量电力系统 新能源场站并网测试 

分 类 号：TM721[电气工程—电力系统及自动化]