| 摘要: |
| 直流串联故障电弧具有隐蔽性、危害性，易导致光伏火灾。通过研究动态弧隙电弧的特性，提出改进Paukert电弧模型，弥补了Paukert模型及其修正模型无法准确模拟弧隙连续变化电弧的不足。在不同条件下，该模型的电弧电流、电压、电阻、功率波形与实验数据的匹配度均达到了84 %以上，具有精度高、适用范围较广等优势。针对微弱电弧故障定位难题，提出一种基于电流多尺度信息的故障定位方法：利用奇异谱分析对电流信号进行多尺度频段划分；根据故障电弧特性，设置峭度和排列熵阈值排除故障信息少、信噪比低的频段，实现故障信号的全频段分析与提取；采用三点对称差分能量算子(DEO3S)增强故障信号，以精确标定故障波位置。测试结果表明，该方法有效避免了特征丢失导致的定位误差增大问题，即使在同步时钟时差较大以及干扰工况下，误差也小于2.2%。 |
| 关键词: 光伏系统 直流电弧故障 改进Paukert电弧模型 故障定位 |
| DOI：10.16081/j.epae.202601007 |
| 分类号:TM615 |
| 基金项目:国家自然科学基金资助项目(52277136) |
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| Modeling of dynamic impedance characteristics and location approach for DC arc faults in PV systems |
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Chen Lijun1, Xu Zhihong1,2,3
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1.College of Electrical Engineering and Automation, Fuzhou University, Fuzhou 350116, China;2.Fujian Key Laboratory of New Energy Generation and Power Conversion, Fuzhou 350116, China;3.Engineering Research Center of Smart Distribution Grid Equipment Fujian Province University, Fuzhou 350116, China
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| Abstract: |
| Owing to the concealed and hazardous nature of DC series fault arc, it is easy to cause photovoltaic(PV) system fire. By studying the characteristics of dynamic arc-gap arc, an improved Paukert arc model is proposed, which makes up for the deficiency that the Paukert model and its modified models cannot accurately simulate arc with continuous arc-gap changes. Under diverse conditions, the model exhibits robust agreement with experimental results, achieving over 84 % consistency across the key electrical characteristics, such as current, voltage, resistance and power, thereby validating its advantage and applicability. To address the challenge of locating elusive arc faults, a novel method based on multi-scale current information is proposed. Singular spectrum analysis is used to divide the current signal into multi-scale frequency bands. Based on the characteristics of fault arcs, kurtosis and permutation entropy thresholds are set to exclude frequency bands with limited fault information and low signal-to-noise ratio, enabling full-frequency-band analysis and fault signal extraction. The three-point symmetric differential energy operator(DEO3S) technique is employed to enhance the fault signal to accurately calibrate the fault wave location. The testing results show that this method effectively avoids the problem of increased location error caused by feature loss, and the error is less than 2.2% even under the conditions of large synchronization clock time difference and interference. |
| Key words: photovoltaic system DC arc fault improved Paukert arc model fault location |
