电工技术学报2024，Vol.39Issue(19)：6018-6038,6053,22.DOI:10.19595/j.cnki.1000-6753.tces.231270
基于基波同步相量的次/超同步振荡参数辨识探究:频谱特性和关键问题
Research on Subsynchronous/Supersynchronous Oscillation Parameter Identification Based on Fundamental Synchrophasor:Spectrum Characteristics and Essential Issues
摘要
Abstract
Subsynchronous oscillations(SSO)caused by considerable renewable generation and power electronic equipment seriously affect the stability of power systems.The parameter identification of sub/supersynchronous oscillations based on fundamental synchrophasors,which are provided by the wide-area measurement system(WAMS)and phasor measurement units(PMU),has the core advantages of wide-area synchronization and high refresh rate.These advantages will enhance the dynamic monitoring of sub/supersynchronous oscillations significantly.Based on the complex spectrum characteristics of the fundamental synchrophasors under sub/supersynchronous oscillations,this paper summarizes and analyzes the parameter identification characteristics and essential issues of the existing parameter identification techniques for sub/supersynchronous oscillations.First,the identified frequency range,the coupling characteristics of each component,and the phase reversal characteristics are analyzed according to the spectrum of synchrophasors.Then,the essential issues of the parameter identification are analyzed,including the spectrum leakage problem,the decoupling problems of the coupled relationship of the oscillational component and the coupled relationship of the fundamental component,respectively.Focusing on the spectrum-based techniques,three essential difficulties in solving the above problems are concluded and analyzed:the problem of effectively identifying the supersynchronous component considering the coupled relationship between the sub/supersynchronous components,the adaptability of parameter identification under different synchrophasor refresh frequencies,and the issue of dealing with spectrum leakages to shorten the data window.Thus,this paper summarizes the corresponding solutions and looks forward to the possible technological breakthroughs in the future. The results of simulation data and actual PMU data in different cases show that in the case of a single subsynchronous oscillation component,a couple of sub/supersynchronous oscillation components,and multiple couples of sub/supersynchronous oscillation components,spectrum-based techniques can effectively identify parameters using a sampling frequency of 100 Hz or under a given applicable range using a sampling frequency of 50 Hz. The following conclusions can be drawn: (1)The sub/super-synchronous oscillation parameter identification with synchrophasors is affected by the synchrophasor sampling frequency(i.e.,the reporting rate),and the identifiable frequency range conforms to the sampling theorem with complex numbers.Specifically,using synchrophasors with a sampling frequency of 100 Hz can identify the parameters of all sub/supersynchronous components without additional information;When the sampling frequency of synchrophasors is 50 Hz,additional conditions are needed to distinguish the wrong results to identify the sub/supersynchronous oscillation parameters. (2)The most essential problem of sub/supersynchronous oscillation parameter identification based on synchrophasors is how to use a shorter synchrophasor sequence to achieve high-precision parameter identification,which may also be one of the breakthroughs in future parameter identification techniques. (3)The influence of the frequency coupled relationship between the sub/supersynchronous oscillations on the parameter identification needs to be considered.The coupled relationship between the sub/supersynchronous components is the coupling of the positive/negative frequencies of the oscillation rather than the mutual spectrum leakage,which is completely different from the influence between the fundamental component and the sub/supersynchronous component. (4)The advantages of the spectrum-based techniques are simple with low computational complexity.The spectrum results are especially suitable for the case of multiple pairs of oscillational components.However,the DFT-based methods need to approximate the spectrum leakage,which makes it difficult to further shorten the data window even if a better window function is used,and the non-DFT-based methods may make a breakthrough in this problem. (5)The problem of data loss and bad data in the synchrophasor sequence may exist in practical applications and needs to be considered.The existing methods rely on the continuity of the synchronous phasor sequence without an in-depth study of the above problems,and it will be another breakthrough point in the practical application of the sub/supersynchronous oscillation parameter identification method based on the synchronous phasor.关键词
同步相量/次/超同步振荡/参数辨识/广域测量系统/频谱分析Key words
Synchrophasor/sub/supersynchronous oscillation/parameter identification/wide-area measurement system(WAMS)/spectral analysis分类
信息技术与安全科学引用本文复制引用
张放,李佳欣,史静舒..基于基波同步相量的次/超同步振荡参数辨识探究:频谱特性和关键问题[J].电工技术学报,2024,39(19):6018-6038,6053,22.基金项目
国家自然科学基金资助项目(52077004). （52077004）
