Circuit single-phase ground distance measurement method

The invention discloses a circuit single-phase ground distance measurement method in the field of relay protection technique of the power system. In the method, the distance from a protection installation point to a ground fault point by calculating the vector difference between the phase voltage of a fault phase of the protection installation point and the fault voltage of the single-phase ground fault point can be calculated. The method has the advantages of high measurement accuracy and practical value without being influenced by the load current and the transition resistance.