The invention discloses a low-
voltage AC / DC power distribution mode conversion
system and a
sequential control method and device thereof, and relates to the technical field of
power transmission and distribution of power systems. The
system comprises a distribution power supply, a distribution line, a load, a sending end converter, a receiving end converter and a plurality of circuit breakers. According to the
sequential control method of the low-
voltage AC / DC power distribution mode conversion
system, the states of the current and
voltage in a system line are detected, the opening and closing actions of different circuit breakers are controlled, the power supply transmits power to the load through the sending end converter and the receiving end converter, and switching from an
alternating current power supply mode to a
direct current power supply mode is completed. The switching
rapidity and reliability are ensured by determining the switching control scheme of the switches at the two sides by detecting the voltage and current change conditions at the two sides, the alternating-current power distribution mode is smoothly switched to the direct-current power supply mode when the terminal demand power is increased and the
voltage drop is obvious, a communication line does not need to be additionally arranged, the cost is low, and the safety of components, such as the converter, etc., and the user power supply continuity can be ensured.