To ensure the reliable arc suppression of single-phase-to-ground fault in the power distribution networks, and improve the control performance of the arc-suppression equipment, a flexible arc-suppression method for the power distribution networks based on quasi-PR control is proposed in this paper. A three-phase cascaded H-bridge converter is utilized as the main circuit of the arc-suppression equipment, which is directly connected to the bus of the power distribution networks, and would realize full compensation for the single-phase-to-ground fault current. Besides, the digital realization of the quasi-PR controller is also discussed. Compared with the traditional PI controller, the quasi-PR controller can track sinusoidal signals with zero error, so as to obtain a better control effect. The simulation and experimental results show that the proposed method could achieve an excellent performance of suppressing fault current and extinguishing the arc.

Flexible arc-suppression; power distribution networks; quasi-PR controller; single-phase-to-ground fault