{
  "abstract": "Under weak-grid conditions, phase-locked loops (PLLs) are essential for synchronizing grid-connected inverters with the utility grid. However, conventional PLLs suffer from insufficient DC-offset and harmonic rejection capabilities, and the coupling between PLL dynamics and grid-voltage feedforward (GVF) may lead to system instability under weak-grid conditions. To address these issues, this paper proposes an extended-state third-order generalized integrator PLL (ES-TOGI PLL) with an enhanced voltage feedforward path. The ES-TOGI structure integrates a DC-offset estimation module and an inertial compensation loop, which suppresses the DC component from 0.0355% to 0.0135% and attenuates the third harmonic from 0.161% to 0.137% under distorted grid conditions. Meanwhile, the enhanced feedforward path, implemented via all-pass and high-pass filters, improves the system phase margin and ensures stable operation under weak-grid conditions with a short-circuit ratio (SCR) of 2. Experimental results demonstrate that the ES-TOGI PLL reduces the output current of total harmonic distortion (THD) from 7.70% (without PLL) to 5.75%, and the enhanced feedforward further lowers the THD to 4.63%, outperforming conventional SOGI, ESOGI, and AFAPLL structures. These results confirm that the proposed ES-TOGI PLL with enhanced feedforward provides an effective solution for robust grid synchronization under non-ideal grid conditions.",
  "abstract_shown": true,
  "affiliations": [
    "School of Information Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Xiaoguang Kong"
    },
    {
      "affs": [
        0
      ],
      "name": "Feixian Chen"
    },
    {
      "affs": [
        0
      ],
      "name": "Xiaotian Xu",
      "orcid": "0009-0004-7850-7925"
    },
    {
      "affs": [
        0
      ],
      "name": "Xiaonan Dong"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/f9ypj2kwr1fef.bib",
  "cited_by": 0,
  "doi": "10.3390/math14193620",
  "fulltext_url": null,
  "id": "f9ypj2kwr1fef",
  "issns": [
    "2227-7390"
  ],
  "landing_url": "https://www.mdpi.com/2227-7390/14/19/3620",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2207|Microgrid Control and Optimization"
    ]
  ],
  "openalex": "W7220862860",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-07",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/f9ypj2kwr1fef.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:29Z",
      "native_id": "10.3390/math14193620",
      "source": "crossref",
      "url": "https://www.mdpi.com/2227-7390/14/19/3620"
    }
  ],
  "subjects": [
    {
      "field": "mathematics",
      "origin": "issn:2227-7390",
      "subfield": "general"
    }
  ],
  "title": "Coordinated Design of Extended-State Observer-Based SOGI-PLL and Optimized Voltage Feedforward for Enhanced Disturbance Rejection",
  "title_text": "Coordinated Design of Extended-State Observer-Based SOGI-PLL and Optimized Voltage Feedforward for Enhanced Disturbance Rejection",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:29Z",
  "url": "https://research.draconitic.com/paper/f9ypj2kwr1fef",
  "venue": "Mathematics",
  "versions": []
}