考虑高比例逆变型分布式电源接入的阻抗差动保护  

Impedance differential protection for integration of a high proportion of inverter-based distributed generation

作　　者：罗国敏[1] 吴梦宇 谭颖婕 赵祎薇 和敬涵[1] 张衡 LUO Guomin;WU Mengyu;TAN Yingjie;ZHAO Yiwei;HE Jinghan;ZHANG Heng(School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044,China;State Grid Beijing Electric Power Company Maintenance Branch,Beijing 100073,China)

机构地区：[1]北京交通大学电气工程学院,北京100044 [2]国网北京市电力公司检修分公司,北京100073

出　　处：《电力系统保护与控制》2025年第7期75-87,共13页Power System Protection and Control

基　　金：国家自然科学基金项目资助(U23B6007)。

摘　　要：目前配电网具备的通信基础设施难以应对高数据同步的需求,且兆瓦级分布式电源(distributed generator,DG)主要采用T接方式并网,影响了差动保护的灵敏性和可靠性。为解决上述问题,提出了一种考虑高比例逆变型分布式电源接入的阻抗差动保护。首先,考虑分布式电源在低电压穿越期间的故障输出特性,挖掘区内外故障时故障分量阻抗动作量和制动量关系的显著差异,构建了故障分量阻抗差动保护判据。其次,由于电压跌落严重时故障分量特征不显著,构建了适用于高电压跌落的正序阻抗比幅判据。两者相互配合,实现保护的可靠性。最后,在Matlab/Simulink中建立实际配电网模型,验证了该保护方法的有效性和可靠性。相较于传统电流差动保护,该方法减少了对数据同步的需求,提高了过渡电阻的耐受能力,适用于分布式电源高渗透率的场景。At present,the communication infrastructure available in distribution networks makes it difficult to cope with the demand for high data synchronization,and megawatt-level distributed generators(DGs)are mainly connected to the network using the T-connection method.This affects the sensitivity and reliability of differential protection.To solve these problems,this paper proposes an impedance differential protection considering the integration of a high proportion of inverter-based distributed generation.First,a fault component impedance differential protection criterion is constructed by considering the fault output characteristics of DGs during low-voltage ride-through,and the significant differences in the fault component impedance action and braking quantities during external and internal faults are identified.Next,because of the lack of distinct fault component characteristics during severe voltage dips,a positive-sequence impedance ratio magnitude criterion is introduced,specifically designed for high-voltage dips.These two criteria work together to ensure the reliability of the protection system.Finally,a practical distribution network model is established in Matlab/Simulink to verify the effectiveness and reliability of the proposed protection method.Compared with traditional current differential protection,the proposed method alleviates the need for data synchronization,improves the tolerance to transition resistance,and is suitable for scenarios with high penetration of DG.

关 键 词：配电网 分布式电源 阻抗差动保护 CT饱和 

分 类 号：TM77[电气工程—电力系统及自动化]