Method of realizing line-to-ground fault phase selection by using sequence voltage phase characteristic

The invention discloses a method of realizing line-to-ground fault phase selection by using a sequence voltage phase characteristic. The method comprises the steps of firstly using the phase relation between zero-sequence voltage and A phase negative sequence voltage to form a criterion and accurately judging whether a transmission line fault is a grounded short circuit fault; secondarily using the magnitude relation between interphase fault impedance and setting impedance to form a criterion; and differentiating a single-phase grounded short circuit fault and a two-phase grounded short circuit fault. When a high impedance grounded short circuit fault occurs on a transmission line at a weak power source side and under the condition that the system operation mode is changed greatly, the method is high enough in phase selection sensitivity, the specific grounded fault phase can be accurately judged, the method is applicable to the fault phase selection of the whole fault process of the transmission line grounded short circuit fault, and is applicable to the fault phase selection of a climbing transmission line high impedance grounded short circuit, and accurate and reliable fault phase information can be provided for distance protection and automatic reclosing lock correct operation.