Suppression and stability analysis of frequency coupling effect in grid‑connected inverters

Xiaohuan Wang; Aihua Yang; Yang Liu; Xiaojun Zhao

Suppression and stability analysis of frequency coupling effect in grid‑connected inverters

Vol. 23, No. 6, pp. 945-958, Jun. 2023

10.1007/s43236-023-00591-6

Grid-connected inverter

Frequency coupling eff ect

Impedance modeling

Stability control

Abstract

With the proposal of the “dual carbon target” in China, the rapid development of renewable energy, mainly photovoltaic and wind power, has been promoted. However, a large amount of renewable energy connected to a grid results in its proportion in the power system going from a low state to a high state. Under a high proportion, the asymmetry of the control structure or parameters in the three-phase grid-connected inverter controller lead to a strong coupling relationship between the sub/super synchronous frequency components, or frequency coupling effect (FCE). This phenomenon can deteriorate the power quality of the inverter system, amplify the harm of frequency oscillation, and even cause system disassembly. To solve the above problems, a unified impedance model considering the FCE induced by the phase-locked loop (PLL), the current loop (CL), and the power outer loop (POL) is established. Based on the established output impedance model, a parameter optimization theoretical analysis method is designed considering the critical stability of the PLL bandwidth and the CL asymmetry degree. Meanwhile, an improved control strategy for the PLL and the POL is proposed. Experimental results show that the proposed parameter optimization and structure improvement strategies can effectively suppress the infl uence of frequency coupling and enhance system stability. Finally, simulation and experimental results verify the correctness of the theoretical analysis and the eff ectiveness of the proposed strategy.

Statistics

Show / Hide Statistics

Cumulative Counts from September 30th, 2019
Multiple requests among the same browser session are counted as one view. If you mouse over a chart, the values of data points will be shown.

Cite this article

[IEEE Style]

X. Wang, A. Yang, Y. Liu, X. Zhao, "Suppression and stability analysis of frequency coupling effect in grid‑connected inverters," Journal of Power Electronics, vol. 23, no. 6, pp. 945-958, 2023. DOI: 10.1007/s43236-023-00591-6.

[ACM Style]

Xiaohuan Wang, Aihua Yang, Yang Liu, and Xiaojun Zhao. 2023. Suppression and stability analysis of frequency coupling effect in grid‑connected inverters. Journal of Power Electronics, 23, 6, (2023), 945-958. DOI: 10.1007/s43236-023-00591-6.