Analysis of Harmonic Resonance Characteristics in Grid-Connected LCL Virtual Synchronous Generator

Sustainability

Xiangjun Li¹  Zhengwen Yang²  Fen Tang²  Jingya Jiang²  Wei Wang²  Xuezhi Wu² 

[1] Key Laboratory of Control and Operation of Renewable Energy and Storage Systems, Energy Storage and Electrical Engineering Department, China Electric Power Research Institute, Beijing 100192, China;National Active Distribution Network Technology Research Center (NANTEC), Beijing Jiaotong University, Beijing 100044, China;

关键词: virtual synchronous generator;    harmonic resonance;    state-space modeling;    SVD;    eigenvalue;   

DOI  :  10.3390/su13084261

来源: DOAJ

【 摘 要 】

The virtual synchronous generator (VSG), which emulates the essential behavior of the conventional synchronous generator, has attracted great attention. This paper proposes to analyze the harmonic resonance characteristics in VSG using the state-space model. The analysis is based on a full-order state-space small-signal model that fully considers the dynamic of the inner loops and the VSG-based outer power control loop. Participation analysis is used to point out the contributions of different states to the eigenvalues. Moreover, eigenvalue locus and singular value decomposition (SVD) are applied together to evaluate the impact of the inner loop parameters on the harmonic resonance characteristics around the LCL filter resonance frequency. The analysis indicates that the harmonic resonance instability is mainly caused by decreasing the proportional gains of the current loop and the voltage loop. Finally, extensive numerical simulation and experimental results are given to verify the validity of the theoretical analysis. Both the simulation and experimental results indicate that the voltage of the common coupling point is unstable after decreasing the proportional gains of the current and voltage controllers. As K_pc decreases from 5 to 0.4 or K_pv decreases from 0.6 to 0.2, the harmonic distortion factor (HDF) around the LCL filter resonance frequency increases. Furthermore, the consistency of simulation results, experimental results, and the theoretical analysis results is validated.

【 授权许可】

Unknown