High-voltage DC-DC conversion device

The invention relates to a high-voltage DC-DC conversion device comprising a cascade modular converter, a double-winding medium- and low-frequency sinusoidal transformer and an input parallel modular converter. The cascade modular converter comprises two bridge arms the same in structure. Each of upper and lower half bridge arms comprises at least two positive half-bridge topology power modules and a reactor. The double-winding medium- and low-frequency sinusoidal transformer comprises a high-voltage primary winding and a low-voltage secondary winding coupled to each other. Two leads of the high-voltage primary winding are connected to two contacts of the two bridge arms respectively. The input parallel modular converter comprises a modular converter submodule or at least two mutually parallel modular converter submodules. The input end of every submodule is connected to the low-voltage secondary winding. The high-voltage DC-DC conversion device has the advantages that the problems of voltage withstanding, voltage sharing and insufficient transmission capacity in high-voltage switching devices of the existing equipment are solved; the high-voltage DC-DC conversion device is significant to quickening the utilization and marketization progress of high-voltage DC-DC conversion devices.