A Cosine Similarity Based Non-unit Protection Method for MTDC grid

• Published in: 2022 IEEE 5th Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC) Vol. 5; pp. 196 - 199
• Main Authors: Huang, Qiang, Li, Kuan, Li, Yudun, Fan, Rongqi, Wang, Anning, Liang, Zhengtang, Zhang, Guohui, Sun, Yuntao
• Format: Conference Proceeding
• Language: English
• Published: IEEE 16-12-2022
• Subjects: Automatic voltage control; Automation; Cosine similarity; Fault diagnosis; Information management; MTDC grid; protection method; PSCAD; Simulation; Transient analysis; Transient current; Transient voltage
• ISSN: 2693-2776
• DOI: 10.1109/IMCEC55388.2022.10020027

A series of fast protection methods for multi-terminal DC (MTDC) grid have been proposed. However, most of these methods simply use voltage change rate or current change rate, but do not make full use of transient voltage and current information to identify fault regions. This paper proposed a protection method based on the cosine similarity of the transient voltage and transient current. Firstly, the characteristics of transient voltage and current in the case of short-circuit fault are analyzed. Then, the cosine similarity of the transient voltage and the current is introduced, and a protection method is constructed based on the cosine similarity difference of the internal faults and external faults. Finally, a simulation model is built in PSCAD, and the validity of proposed protection method is verified.