To prevent single-phase adaptive reclosure from overlap and permanent fault

accurate identification of fault type on the transmission line is necessary. With regard to the UHV AC transmission lines with shunt reactors

the authors calculate the amplitude ratio of the voltage on neutral reactor to the voltage on the fault line-end in the conditions of transient fault and permanent fault

respectively. Because the two fault conditions exhibit significantly different voltage amplitude ratios

this parameter can be taken as a criterion to accurately identify the two faults. Simulations with the software ATP/EMTP show that the proposed method works accurately and efficiently.