Novel methods for high-impedance ground-fault protection in low-voltage supply systems

K. K. Li, Wai Lok Chan, Zeng Xiangjun, Yin Xianggen

Research output: Journal article publicationJournal articleAcademic researchpeer-review

16 Citations (Scopus)

Abstract

Many high-impedance ground faults (HIGFs) that happen in low-voltage (LV) systems often cause customer supply loss, fire, and human safety hazards. Traditional ground-fault protection is provided by the residual current circuit breaker (RCCB). The RCCB is usually employed in an analogue measuring circuit and often causes nuisance tripping due to capacitive leakage current and load-switching operations. It offers only ground fault protection to a certain extent and has difficulty in detecting HIGFs associated with a dielectric material defect. In this paper active power variation–based protection for HIGFs is developed, and a dissipation factor (DF)–based criterion for identifying loads witching operation is proposed. They are implemented by cross-correlation analysis between phase voltage and residual current in single-phase networks. A digital protection scheme is also designed. EMTP simulation results show that the new protection can remove the influences of capacitive leakage current and load-switching operations and is able to detect HIGFs and prevent electric shock with high sensitivity and robustness.
Original languageEnglish
Pages (from-to)1133-1150
Number of pages18
JournalElectric Power Components and Systems
Volume31
Issue number12
DOIs
Publication statusPublished - 1 Jan 2003

Keywords

  • Correlation analysis
  • Ground-fault protection
  • High-impedance fault
  • Low voltage systems

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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