基于光伏自适应注入量的配电网单相接地故障保护方法  

A Single Phase Grounding Fault Protection Method for Distribution Networks Based on Photovoltaic Adaptive Injection Amount

作　　者：许守东 潘馨钰 李世伟 欧阳金鑫[2] 张丽 丁正宏 XU Shoudong;PAN Xinyu;LI Shiwei;OUYANG Jinxin;ZHANG Li;DING Zhenghong(Electric Power Research Institute,Yunnan Power Grid Co.,Ltd.,Kunming 650200,Yunnan,China;State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Chongqing 400044,China;Honghe Power Supply Bureau,Yunnan Power Grid Co.,Ltd.,Honghe 661100,Yunnan,China)

机构地区：[1]云南电网有限责任公司电力科学研究院,云南昆明650200 [2]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆400044 [3]云南电网有限责任公司红河供电局,云南红河661100

出　　处：《电网与清洁能源》2023年第9期140-150,共11页Power System and Clean Energy

基　　金：国家自然科学基金面上项目(51877018);云南电网有限责任公司科技项目(YNKJXM-20220189)。

摘　　要：随着配电网中分布式光伏发电渗透率不断升高,配电网单相接地故障对设备和人身安全以及电网稳定的影响日趋严峻。但是,由于光伏短路电流受限、故障行为受控、输出特性耦合造成配电网故障过程具有多态性,可能使得中性点小电流接地配电网单相故障选线准确度进一步降低。文中提出了基于光伏自适应注入附加特征信号的配电网单相接地故障保护方法。兼顾光伏低电压穿越要求、故障识别需求和设备安全,提出了光伏自适应特征频率电流注入策略,解析了配电网中特征频率电流的分布,分析了馈线的特征频率电流的幅值特征和相位特征,提出了基于特征频率电流特征的配电网单相接地故障选线保护方法。算例表明,所提出的方法能够准确实现不同故障位置,以及不同过渡电阻下含光伏配电网单相接地故障的故障选线。With the increasing penetration rate of distributed photovoltaic power generation in the distribution network,the impact of single phase to ground faults on equipment and personal safety,as well as grid stability,is increasingly severe.However,due to the limitation of photovoltaic short-circuit current,controlled fault behavior,and coupled output characteristics,the fault process in the distribution network is of polymorphism,which may further reduce the accuracy of single-phase fault line selection in neutral grounded distribution networks.Therefore,a single phase to ground faults protection method for distribution networks based on photovoltaic adaptive injection of additional characteristic signals is proposed in the paper.A photovoltaic adaptive characteristic frequency current injection strategy is proposed,which takes into account the requirements of photovoltaic low voltage ride through,fault identification requirements,and equipment safety.The distribution of characteristic frequency currents in distribution networks is analyzed,and the amplitude and phase characteristics of characteristic frequency currents in feeders is analyzed.A single phase grounding fault line selection protection method based on characteristic frequency current characteristics in distribution networks is proposed.The simulation results shows that proposed method can accurately achieve fault line selection for single phase to ground faults in photovoltaic distribution networks at different fault locations and transition resistances.

关 键 词：光伏发电 配电网 故障选线 单相接地故障 注入信号 

分 类 号：TM771[电气工程—电力系统及自动化]