逆变器启动工况下光伏直流串联电弧故障识别方法  

Diagnosis of Photovoltaic DC Series Arc Fault Under Inverter Startup Conditions

作　　者：赵双乐 刘志峰 侯晓鑫 于佳丽 游国栋[1] ZHAO Shuangle;LIU Zhifeng;HOU Xiaoxin;YU Jiali;YOU Guodong(College of Electronic Information and Automation,Tianjin University of Science and Technology,Tianjin 300222;School of Electrical Engineering,Hebei University of Technology,Tianjin 300401)

机构地区：[1]天津科技大学电子信息与自动化学院,天津300222 [2]河北工业大学电气工程学院,天津300401

出　　处：《高电压技术》2024年第10期4691-4702,共12页High Voltage Engineering

基　　金：国家自然科学基金(51607055,60771014)。

摘　　要：光伏系统逆变器启动时,最大功率点跟踪(maximum power point tracking,MPPT)等内部控制算法会引起电流瞬态变化,从而干扰直流串联电弧故障诊断装置对故障特征的正确识别,造成误动作。为此,针对逆变器启动情况下电弧故障检测装置易出现误动作的问题,提出一种基于无量纲特征量和灰色关联度的故障检测方法。首先分析了电弧故障RLC等效振荡模型,得出电弧电流信号在频域具有较宽的频带;然后分别对逆变器工况与电弧故障实测电流的频域特性进行了对比,发现正常工况与故障在1~20 kHz和40~60 kHz范围内的频谱在波峰陡峭度、所处位置等方面存在差别,使用峭度、偏度、峰值因子、冲击因子、裕度因子、波形因子等提取频谱特征,计算灰色关联度并进行故障识别;最后,分别使用模拟平台和实际光伏系统进行了试验验证。结果表明,所提方法可有效避免逆变器启动造成的干扰,提高故障识别的准确度。When the inverter of photovoltaic system is started,internal control algorithms such as maximum power point tracking(MPPT)will cause current transient changes,interfere with the correct identification of fault characteristics by DC series arc fault diagnosis device,and cause misoperation.Aiming at the problem that the arc fault detection device is prone to misoperation when the inverter is started,we proposed a fault detection method based on dimensionless feature quantity and grey correlation degree.Firstly,the RLC equivalent oscillation model of arc fault is analyzed.It can be seen that the arc current signal has a wide frequency band in the frequency domain.Then,the frequency domain characteristics of the measured current under arc fault and inverter working conditions are compared.It is found that there are differences in peak steepness and position between the spectrum diagram of fault and normal working conditions in the range of 1~20 kHz and 40~60 kHz.The spectrum features are extracted by using steepness,skewness,peak factor,impact factor,margin factor and waveform factor,and the fault is identified according to the grey correlation degree.Finally,the simulation platform and the actual photovoltaic system are used for experimental verification.The results show that the method can be adopted to effectively avoid the interference caused by inverter startup and improve the accuracy of fault identification.

关 键 词：直流串联电弧 光伏系统 逆变器启动 灰色关联度 无量纲特征量 RLC振荡模型 峭度 偏度 

分 类 号：TM501.2[电气工程—电器] TM615