储能科学与技术 ›› 2025, Vol. 14 ›› Issue (3): 1299-1309.doi: 10.19799/j.cnki.2095-4239.2024.1136

• 储能新锐科学家专刊 • 上一篇    下一篇

基于李萨如图形-阻抗辨识的构网型储能混合式孤岛检测方法

王曦1(), 滕予非1, 石鹏1, 张蔚萱2, 陈保瑞1, 白珈于1, 杜新伟3, 苟竞3, 胡鹏飞4()   

  1. 1.国网四川省电力公司电力科学研究院,四川 成都 610095
    2.浙江大学工程师学院,浙江 杭州 310015
    3.国网四川省电力有限公司,四川 成都 610041
    4.浙江大学电气工程学院,浙江 杭州 310027
  • 收稿日期:2024-12-01 修回日期:2025-01-02 出版日期:2025-03-28 发布日期:2025-04-28
  • 通讯作者: 胡鹏飞 E-mail:5045641@qq.com;hpf@zju.edu.cn
  • 作者简介:王曦(1988—),男,博士,主要研究方向为电力系统稳定与控制,E-mail:5045641@qq.com
  • 基金资助:
    国家电网有限公司科技项目:构网型储能运行理论、控制方法与样机研发项目(52199723002A)

A hybrid islanding detection method based on the Lissajous Pattern and impedance for grid-forming energy storage inverter

Xi WANG1(), Yufei TENG1, Peng SHI1, Weixuan ZHANG2, Baorui CHEN1, Jiayu BAI1, Xinwei DU3, Jing GOU3, Pengfei HU4()   

  1. 1.State Grid Sichuan Electric Power Research Institute, Chengdu 610095, Sichuan, China
    2.Polytechnic Institute, Zhejiang University, Hangzhou 310015, Zhejiang, China
    3.State Grid Sichuan Electric Power Co. , Ltd. , Chengdu 610041, Sichuan, China
    4.College of Electrical Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China
  • Received:2024-12-01 Revised:2025-01-02 Online:2025-03-28 Published:2025-04-28
  • Contact: Pengfei HU E-mail:5045641@qq.com;hpf@zju.edu.cn

摘要:

快速可靠地识别非计划性孤岛是构网型储能变流器实现并离网运行状态的平滑切换的关键问题,当前孤岛检测方法在负荷与变流器功率零失配时容易失效且阈值难以设定。为此,本工作提出了一种基于电压电流李萨如图形和阻抗辨识的混合式孤岛检测方法。该方法利用基于电压电流李萨如图形的面积与短轴捕捉电压电流特征,当检测得到的孤岛检测指标超出阈值时,注入扰动触发阻抗辨识。李萨如图形-阻抗辨识的混合式检测不仅能够很好地检测到负荷与变流器功率完全匹配时电压电流的微小变化,而且能够很好区分孤岛情况与非孤岛故障。为了解决孤岛检测阈值选取困难且与电网参数高度关联的问题,该方法采用了相对性指标,并利用Ostu法给出了被动检测指标的阈值。最后,通过MATLAB/Simulink仿真和硬件在环实验验证了所提出方法的有效性。实验结果表明,即使在负荷功率与变流器完全匹配且品质因数为2.5时,所提出方法也能有效可靠检测到孤岛现象。

关键词: 电压电流李萨如图形, 孤岛检测, 阻抗辨识, 储能变流器

Abstract:

Rapid and reliable identification of unintentional islanding is crucial for grid-forming energy storage inverters to achieve smooth transitions between grid-connected and islanding operation modes. Current islanding detection methods often fail under perfectly matched loading conditions and struggle with threshold selection. To address this, this study proposes a hybrid islanding detection method based on the V-I Lissajous pattern and impedance. This method utilizes the area and minor axis of voltage-current Lissajous plots to capture the characteristics of voltage and current. When the detected islanding detection indicators fail to meet the threshold, disturbances are injected to identify impedance. The combined Lissajous pattern-impedance identification enables the detection of minor changes in voltage and current under perfectly matched load and converter power while effectively distinguishing islanding conditions from non-islanding faults. To overcome the challenge of threshold selection for islanding detection, which is highly correlated with grid parameters, this method employs relative indicators and uses the Otsu method to determine a threshold for passive detection indicators. The proposed method is verified through MATLAB/Simulink simulation and hardware-in-the-loop experiments. The experimental results show that even with perfectly matched load power with the converter and a quality factor of 2.5, the proposed method effectively and reliably detects islanding phenomena.

Key words: V-I Lissajous pattern, islanding detection, impedance identification, energy storage inverter

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