HAN Jin,XU Guangxue,QIU Yutao,et al.A differential protection method for multi-terminal lines in distribution networks based on the alpha plane of current fault components[J].ZHEJIANG ELECTRIC POWER,2026,45(07):24-34.
HAN Jin,XU Guangxue,QIU Yutao,et al.A differential protection method for multi-terminal lines in distribution networks based on the alpha plane of current fault components[J].ZHEJIANG ELECTRIC POWER,2026,45(07):24-34.DOI: 10.19585/j.zjdl.202607003.
A differential protection method for multi-terminal lines in distribution networks based on the alpha plane of current fault components
To address the challenges in differential protection applications for multi-terminal lines in distribution networks, such as reduced sensitivity, the inability to compensate for capacitive current under no-voltage conditions, and susceptibility of current transformers (CTs) to saturation during external faults, a differential protection method based on the alpha plane of current fault components is proposed. This method builds on the alpha-plane protection principle, constructs an analysis region using vector information of current fault components, and discriminates between internal and external faults through dynamic partitioning. Theoretical analysis is conducted to evaluate the method’s immunity to capacitive current and CT saturation, and simulation studies are performed under various fault types, capacitive current levels, and CT saturation conditions. The results indicate that the proposed method features high sensitivity and a wide discrimination margin, is unaffected by load current, and does not require additional capacitive current compensation devices or CT saturation identification units, making it suitable for application in distribution networks.
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