Current-phase-comparison-based pilot protection for normally closed-loop distribution network with underground cable

Abstract

Summary Closed‐loop operation of distribution network has attracted more attention recently to improve supply reliability and adopt distributed energy resources friendly. But its protection is usually independent of distribution automation system (DAS). This article presents a pilot protection method for closed‐loop distribution network with underground cable by comparing current phase, which can be accomplished by remote terminal units (RTUs) in DAS. Firstly, operation value of RTUs is designed on the current variation after fault and the RTUs are synchronized automatically based on fault signal. Secondly, the current phase characteristic of positive‐sequence fault component is analyzed when various short circuit fault occurs at different locations. Based on the current phase difference, the state of ring network cabinet is classified into four types, and uniform fault location rule by adjacent RTUs is designed. The fault can be located and isolated directly by cooperation of adjacent RTUs. The setting principle and the operation logic for the pilot protection are given, and its performance is analyzed. Finally, simulation model based on PSCAD is constructed. The simulation results prove that this protection can locate and isolate faults timely on the premise of high sensitivity. It has strong ability of enduring fault resistance, and it can fit closed and open operation mode.

Feeder selection method for full cable networks earth faults based on improved K‐means

“…Currently, earth fault feeder selection methods in full cable networks can be divided into three ways, mainly signal injection method [3,4], fault signal features comparison method [5,6], and artificial intelligence fault feeder selection method [7][8][9]. By injecting signals of a specified frequency into the system and then recognizing problematic feeders based on feeder characteristic signals, the signal injection technique detects faulty feeders.…”

Novel Protection Scheme considering Tie Switch Operation in an Open-Loop Distribution System using Wavelet Transform

“…In [15], the protection scheme in a loop-type micro grid was proposed. In [16], the pilot protection scheme in the loop distribution system with a cable was proposed. Some previous works have dealt with protection issues in the closed-loop distribution system.…”