DC power grid topology based on coupling transformer under high impedance grounding and fault positioning method thereof

The invention relates to a DC power grid topology based on a coupling transformer under high impedance grounding, and a fault positioning method thereof. The positioning method comprises the followingsteps: firstly detecting a DC voltage signal of a DC line through a way of detecting the voltage signal, initially judging whether the fault occurs; after judging that the fault occurs, controlling to short-circuit a high-impedance grounding line arranged between the neutral point of the coupling transformer and the ground, in this case, the fault current can produce in the DC line since the highimpedance arranged between the neutral point of the coupling transformer and the ground is short-circuited; and then detecting the fault positioning according to the fault current. Therefore. The fault positioning method is suitable for the DC power grid topology based on the coupling transformer high-impedance grounding, the fault positioning can be realized, and then the fault overhauling can be performed according to t