结合特征根及模态分析法的逆变器多机并网系统谐波扰动响应分析  

Analysis of Harmonic Disturbance Response of Multi-Inverter Grid-Connected System Combining Characteristic Root and Modal Analysis Method

作　　者：李戎 李建文 李永刚 孙伟 Li Rong;Li Jianwen;Li Yonggang;Sun Wei(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Baoding 071003,China;Baoding Power Supply Subsidiary Company of State Grid Hebei Electric Power Supply Co.Ltd Baoding 071000,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),保定071003 [2]国网河北省电力有限公司保定供电分公司,保定071000

出　　处：《电工技术学报》2024年第14期4519-4534,共16页Transactions of China Electrotechnical Society

基　　金：中央高校基本科研业务费专项资金资助项目(2023MS109)。

摘　　要：为了从本质上解释逆变器多机并网系统受到宽频谐波扰动后的动态行为,该文理论推导特征根与系统稳态和暂态响应的解析解,进而利用单个逆变器并网的实例验证了采用特征根分析系统谐波响应的可行性。针对逆变器多机并网系统,阐明特征根与谐振模态的对应关系,使得利用模态分析方法既能解析系统内部支路对不同谐振模态的可激励性和可观测性,又能视系统为一个整体对其稳定性进行分析。最后,通过仿真与实验验证了结合特征根分析逆变器并网系统动态行为的正确性及有效性。The broadband oscillation caused by the interaction of a high proportion of new energy connected to the grid,grid impedance and load is a typical system stability problem.In recent years,some overvoltage phenomena have been difficult to classify into the classical stability problems.The electromagnetic transient process driving this phenomenon differs from the power-angle relationship on the rotor-side generator models using phase-locked loops(PLLs).To explain the dynamic behavior of inverter grid-connected systems disturbed by broadband harmonics,this paper derives a mathematical expression that characterizes the system’s response to harmonic disturbances and analyzes the response’s characteristics.Furthermore,the feasibility of analyzing harmonic responses using characteristic roots is verified by an example of a single inverter connected to the grid.The relationship between the characteristic root and the resonance mode is clarified for multi-inverter grid-connected systems.Finally,the dynamic behavior analysis is verified by simulation and experiments.The harmonic disturbance response expression is derived according to the characteristic roots and the harmonic disturbance.It is found that the system’s response comprises two waveforms:the steady-state response and the transient response.The resonance characteristics of these two responses differ,with the magnitude of the resonance peak closely related to the damping coefficientξ.A large peak occurs whenξis close to 0,gradually decreasing asξincreases,and no steady-state response resonance peak is observed whenξ>0.7.The characteristic root can effectively describe the harmonic disturbance response of inverter grid-connected systems.The dynamic behavior of the system after disturbance can be quantitatively analyzed by calculating the damping coefficient value.When multiple inverters are connected to the grid,the impedance-based system modeling method provides convenience for analyzing the stability of the inverter grid-connected system.The series and p

关 键 词：特征根 谐波扰动 模态分析方法 稳态响应 暂态响应 

分 类 号：TM464[电气工程—电器]