| 引用本文: | 靳俊豪,宋国兵,常仲学,徐瑞东.基于谐波阻抗特性识别的主动式孤岛检测方法[J].电力自动化设备,2025,45(5):128-135. |
| JIN Junhao,SONG Guobing,CHANG Zhongxue,XU Ruidong.Active islanding detection method based on harmonic impedance characteristic identification[J].Electric Power Automation Equipment,2025,45(5):128-135. |
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| 摘要: |
| 针对目前孤岛检测方法存在的源荷功率匹配导致防孤岛保护拒动，多分布式电源并网引发稀释效应，出现电压扰动时防孤岛保护与低电压穿越的运行冲突等问题，在分析系统并网点谐波阻抗特性基础上，基于参数识别思想，提出了一种能够识别孤岛状态并有效区分电压扰动的主动式孤岛检测方法。对分布式光伏并网系统的谐波阻抗特性进行理论分析，由此将并网阻抗在一定频带下进行等效。基于主动探测式保护思想，提出了一种谐波信号同步注入策略。基于参数识别原理列写出包含电阻、电感、电容3个未知参数的频域微分方程组，利用最小二乘优化方法得到以上未知参数，并以此为孤岛判据。仿真结果表明，所提方法能快速可靠地识别孤岛。 |
| 关键词: 分布式并网系统 孤岛检测 谐波阻抗特性 低电压穿越 稀释效应 同步注入 |
| DOI：10.16081/j.epae.202503003 |
| 分类号:TM77 |
| 基金项目:国家自然科学基金资助项目(52107123) |
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| Active islanding detection method based on harmonic impedance characteristic identification |
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JIN Junhao1,2, SONG Guobing1,2, CHANG Zhongxue1,2, XU Ruidong1,2
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1.School of Electrical Engineering, Xi’an Jiaotong University, Xi’an 710049, China;2.State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, Xi’an 710049, China
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| Abstract: |
| Existing islanding detection methods face challenges such as anti-islanding protection failure caused by source-load power matching, dilution effect caused by grid connection of multiple distributed energy sources, and operational conflicts between anti-islanding protection and low voltage ride-through during voltage disturbances. To address these problems, an active islanding detection method based on harmonic impedance characteristics of system grid-connected point and parameter identification is proposed, which can identify islanding state and effectively distinguish voltage disturbance. The harmonic impedance characteristics of distributed photovoltaic grid-connected system are theoretically analyzed, and the grid-connected impedance is equivalent in a certain frequency band. Based on the principle of active detection protection, a synchronous injection strategy of harmonic signals is proposed. A set of frequency domain differential equations, which include the three unknown parameters of resistance, inductance and capacitance, is established based on the principle of parameter identification. The least square optimization method is used to obtain these unknown parameters, which serves as the criterion for islanding detection. Simulative results demonstrate that the proposed method can quickly and reliably detect islanding. |
| Key words: distributed grid-connected system islanding detection harmonic impedance characteristics low voltage ride-through dilution effect synchronous injection |
