Abstract: Two cascaded H-bridge converters (CHBC) are proposed to regulate the zero-sequence reactive current of distribution networks flexibly to realize the online ice-melting of ice-covered lines without power outages. The two CHBCs are connected in series to the grounding transformer at the head and end of the ice-covered lines. The zero-sequence voltage of the distribution networks is regulated by the end CHBC within the permissible range of insulation, and the resulting zero-sequence capacitive current to ground flows through the three-phase ice-covered conductors as ice-melting current, which realizes a better effect than the single-phase short-circuit current ice-melting. By regulating the capacitance current to the ground of the distribution networks through the head CHBC, the size of the ice-melting current can be adjusted arbitrarily. The proposed method does not require a single-phase grounding short circuit and can simultaneously accurately regulate the ice-melting current to melt ice in three-phase lines. CHBCs only have reactive interaction with the distribution networks, saving the capacity of DC sources, and the sum of power interactions is zero, which does not affect the normal supply voltage of the distribution networks, and there is no need for power outages for the entire network loads. The simulation and experimental results verify the feasibility and effectiveness of the proposed method and control scheme.