含分布式光伏低压交流系统短路快速保护方法  

Fast Short-circuit Protection Method for Low-voltage AC System With Distributed Photovoltaic

作　　者：庄胜斌 缪希仁[1] 郭谋发[1] ZHUANG Shengbin;MIAO Xiren;GUO Moufa(College of Electrical Engineering and Automation,Fuzhou University,Fuzhou 350116,Fujian Province,China)

机构地区：[1]福州大学电气工程与自动化学院,福建省福州市350116

出　　处：《电网技术》2024年第12期5138-5148,共11页Power System Technology

基　　金：国家自然科学基金项目(51677030);省部共建电工装备可靠性与智能化国家重点实验室(河北工业大学)开放基金项目(EERI_KF2020005);福建省高校产学合作项目(2023H6006)。

摘　　要：低压交流系统过电流原理短路保护方法受限于短路检测特征单一,已难以满足复杂工况下系统运行保护,分布式光伏、储能等柔性装置接入给低压保护技术带来新挑战。因此,提出节点自治的含分布式光伏低压交流系统短路快速保护方法。首先,以短路电流、电压瞬时幅值构建支路状态特征,研究短路状态早期辨识方法。其次,引入同节点各支路短路电流极性信息,设计基于短路电流方向相关性辨识的短路支路保护决策机制。最后,进行低压真型系统及其仿真模型的保护实验。实验结果表明,传统支路和光伏并网支路的短路均可在0.5 ms内检出;不同节点间的保护响应范围合理搭配,且对于同一节点的近端短路,各支路可在短路1 ms内独立决断是否触发保护,保障了保护方法的选择性;保护方法在各类源荷运行工况扰动下不误动,研究成果具有较高的理论和工程价值。Due to the limitation of a single short-circuit detection feature,the short-circuit protection method of a low-voltage AC system based on the over-current principle has been unable to meet the requirements of operation protection under complex working conditions.With the availability of flexible technologies such as distributed photovoltaic and energy storage,low-voltage protection technology has faced new hurdles.Therefore,a node-autonomous fast short circuit protection method for distributed photovoltaic low-voltage AC systems is proposed.Firstly,the characteristics of the branch state are constructed using the instantaneous amplitudes of short-circuit current and voltage,and the early detection technique of short-circuit state is investigated.Secondly,the polarity information of the short-circuit current in each branch of the same node is introduced,and the short circuit branch protection decision mechanism based on the direction correlation identification of the short-circuit current is designed.Finally,the protection experiment of the low voltage physical experiment system and its simulation model are carried out.The experimental results show that the short circuit of both the traditional and photovoltaic branches can be detected within 0.5 ms.The protection response ranges between different nodes are reasonably matched,and for the short circuit at the near end of the outlet of the same node,whether the protection is triggered can be accurately determine in each branch within 1 ms of the short circuit,thus achieving selective protection.The protection method does not malfunction under the disturbance of various source load operating conditions.The research results have high theoretical and engineering value.

关 键 词：低压交流系统 分布式光伏 短路故障 短路状态早期检测 保护决策机制 

分 类 号：TM721[电气工程—电力系统及自动化]