A novel transient directional pilot protection principle based on sequential overlapping derivative transform for AC transmission lines. Issue 1 (28th November 2022)

• Record Type: Journal Article
• Authors: Wang, Bingran; Wang, Zengping; Wang, Zhaochen; Wang, Tong
• Is Part Of: IET generation, transmission & distribution. Volume 17:Issue 1(2023)
• Page Start: 128
• Page End: 145
• Publication Date: 2022-11-28
• Subjects: cross overlapping differential transform -- high frequency component -- relay protection -- transient current; Electric power production -- Periodicals; Electric power transmission -- Periodicals; Electric power distribution -- Periodicals; 621.3105
• DOI: 10.1049/gtd2.12669
• Languages: English
• ISSNs: 1751-8687

Abstract

Abstract: The access of large‐scale renewable energy and power electronic equipment to the power grid makes the power source and short‐circuit paths possess time‐varying characteristics when faults occur, which has a serious impact on the traditional protection based on power frequency components. Besides, higher requirements are needed for relay protection in the power grid. The transient fault current contains a large amount of fault information. First, the bus capacitance has a strong reflection effect on the high frequency signal, and there are obvious differences in the high frequency component of the fault current of internal and external faults. Next, a transient quantity algorithm based on sequential overlapping derivative transform is introduced. The algorithm can effectively suppress the low frequency component and enhance the high frequency component in the current, which simply and effectively highlights the difference between the transient current of internal and external faults. Finally, through the ratio of high frequency energy of each outgoing line, the fault direction can be accurately determined, and the transient directional pilot protection can be formed. The accuracy of the protection scheme is verified by a large number of simulation experiments. Abstract : A novel transient directional pilot protection principle based on sequential overlapping derivative transform is proposed here for AC power grid. The proposed protection can protect the entire line reliably without dead zones, with low computational complexity and short time window. There is no need to select the frequency band and set the protection criterion, and the fault difference will be reflected to a higher level.