The invention discloses a
power grid direct-current flexible
loop closing control device and a control method thereof. The device is a series-parallel connection device and comprises a series connection
coupling unit, a parallel connection
coupling unit, other bypass switch circuits and a
loop closing main controller, wherein each group of series-parallel connection device is connected in series between each section of power distribution line and load, after a
loop closing instruction is received, a loop closing control device is set to work in a
voltage control mode, when the direct-current
bus voltages of the two groups of loop closing devices are consistent, the
system enters a loop closing state, and before loop closing is quitted, the device is set to be in a PQ
control mode, access switches are sequentially disconnected after P and Q are gradually reduced to zero, and the loop closing process is ended. According to the invention, the device has the advantages of being simple in structure, low in cost, less in loop closing monitoring amount compared with
alternating current loop closing, and high in efficiency; and flexible power mutual aid and fault rapid exit can be realized, the
power factor of the
closed loop zone area is adjusted to be optimal, the power supply mode of the distribution network can be flexibly changed, and the
new energy consumption level and the
direct current load accepting capability are improved.