Study on the overcurrent character analysis and its protective system of underground LV distribution networks
SONG Jian-cheng
SHI Zong-yi
YANG Yi
SHI Wen-lin
WEI Hua
ZHAI Sheng-qin
XIE Heng-kun
Abstract：The overcurrent fault characters in underground LV cable distribution networks is analyzed and the fundamental principle of overcurrent protective system is narrated in this paper. Much more attention is paid to the analysis of the method how to define the characteristic curves of phase-sensitive symmetrical short-circuit protection, the design of negative-sequence current filter and the definition of the mathematical model of overload. Besides, the hardware block diagram and software flowchart of the protective system controlled by single-chip microcomputer is also introduced in the paper. The protective system was tested before applied in underground LV distribution networks, The results obtained are conformity with the design specification. It has been verified that the protective distance is enlarged and the protective sensitivity is improved with the protective system. The field experience has shown that the protective system is good practice in stability and reliability, and will be of great applied value in mining industry.
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Publication Date：2001-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 81-86 )