Application of fuzzy set theory to single-phase-to-ground fault line detection

The characteristics of single-phase-to-ground fault and algorithms of fault line selection in power network with neutral earthed via Peterson coil are researched.Traditional single fault line detection method using only some parts of fault information has poor reliability.Therefore,fuzzy set theory is introduced and applied in fault line detection.According to the principle of making use of all fault information,effective fault line detection methods are selected in every fault information field.Fault measure and weight coefficient subordinate function are structured to integrate all kinds of fault information and combine several fault line detection methods by which the detecting performance is improved greatly.Dynamic mould laboratory emulation results show that the new scheme has higher sensitivity and reliability.