Computationally Effective Frequency Transient-Based Transmission Line Protection for Multiterminal VSC-HVdc
Tongkun Lan, Hao Xiao, Yinhong Li, Jinfu Chen
Abstract
For the transmission line fault in multiterminal voltage source converter (VSC) based high-voltage direct current (HVdc), the frequency spectrum of internal fault is obviously higher compared with the external fault. In frequency transient-based protection, the fault is generally identified by the high-frequency component via the professional mathematical algorithm, such as Fourier and wavelet transforms. However, the burdensome computation would slow down the protection operation speed, and the details in the specific frequencies are far beyond the need for fault identification. In this article, a computationally effective protection is proposed without utilizing the complicated mathematical algorithm. Comprehensive index given from the supplemental inductor is developed, which shows the greater value for higher frequency spectrum, and requires fewer algebraic operations. The proposed protection based on the comprehensive index is with superior computational efficiency and maintains the advantage of frequency transient-based protection in fault identification accuracy. The protection performance is validated in four/three-terminal VSC-HVdc.