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ORIGINAL RESEARCH article

Front. Energy Res.
Sec. Smart Grids
Volume 12 - 2024 | doi: 10.3389/fenrg.2024.1517505
This article is part of the Research Topic Advanced Data-Driven Uncertainty Optimization for Planning, Operation, and Analysis of Renewable Power Systems View all 13 articles

Analysis of Transient Characteristics and Fault Ride-through Control of Hybrid Grid-tied Converters with Grid-following and Grid-forming

Provisionally accepted
Baoyu Zhai Baoyu Zhai 1Shuchao Liang Shuchao Liang 1Zhi Xu Zhi Xu 1Fengyi Deng Fengyi Deng 2*Junru Chen Junru Chen 2Haiyang Wu Haiyang Wu 1
  • 1 Xinjiang Electric Power Research Institute of State Grid Xinjiang Electric Power, Co., Ltd., Urumqi, Taiwan Province, China
  • 2 Department of Electrical Engineering, Xinjiang University, Urumqi, China

The final, formatted version of the article will be published soon.

    When the Grid-Following (GFL) and the Grid-Forming (GFM) converters are hybrid-connected to the grid, they are coupled through the grid impedance. During grid faults, the transient characteristics of the two converters become more complex due to this coupling. If one of the converters experiences stability issues, it affects the other, making fault ride-through challenging. A mathematical model for the hybrid grid-connected system of the two converters is first established to analyze the existence conditions of the equilibrium point. Using the phase-plane method, the mutual influence mechanism during faults is revealed. Subsequently, a method to adjust the GFM phase angle based on the degree of voltage sag is proposed, which also improves the phase-locked loop (PLL) of the GFL. The influence of GFL current injection is considered to limit the GFM fault current, thereby achieving hybrid fault ride-through control. Finally, the simulation verifies the effectiveness of the proposed control strategy. The results show that the proposed method can adjust the phase angle to support the grid, ensuring that the GFM outputs more reactive current within the maximum allowable current range. Meanwhile, the GFL injects current according to grid guidelines, effectively preventing overcurrent and phase angle instability of the converters.

    Keywords: grid-following converter, Grid-forming converter, hybrid grid-connected system, stability, hybrid fault ride-through control

    Received: 26 Oct 2024; Accepted: 27 Dec 2024.

    Copyright: © 2024 Zhai, Liang, Xu, Deng, Chen and Wu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Fengyi Deng, Department of Electrical Engineering, Xinjiang University, Urumqi, China

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