The invention discloses a dual-closed-
loop control-based active
voltage arc extinction method and apparatus for a power distribution network in fault. The
arc extinction method comprises the following steps of collecting a three-phase
voltage and a
neutral point voltage of the power distribution network, and judging whether the power distribution network suffers from a
single phase grounding fault or not; if the power distribution network suffers from the
single phase grounding fault, determining a fault phase according to the value of the three-phase
voltage; injecting an
initial current to the power distribution network to obtain a phase voltage and a
neutral point voltage of the fault phase, and determining an optimal injection current through a dual-closed-
loop control method; and injecting the optimal injection current to the power distribution network to realize
arc extinction on an instantaneous
single phase grounding fault. According to the method and the apparatus disclosed by the embodiments, based on the dual-closed-
loop control method, a current is injected to the neutral point of the active arc
extinction apparatus when the power distribution network suffers from the single phase grounding fault; and the fault phase voltage is controlled to be zero, and the reactive current component, the active current component and the
harmonic component of the fault phase are compensated, so as to realize rapid and high-precision complete arc
extinction on the instantaneous single phase grounding fault.