Power supply device for sub-module controller of mmc converter

A power supply apparatus for a sub-module controller of a MMC, comprising:

• a bridge circuit unit including N (N≧2, integer) energy storage units for storing a DC voltage in series-connected sub-modules in the MMC, and multiple power semiconductor devices respectively connected in parallel with the N energy storage units in a form of a bridge and connected in series with each other;
• a switching unit for switching any one of a first output terminal formed at a first end of n (1≦n<N) series-connected energy storage units, among the N energy storage units, and a second output terminal formed at a first end of m (n<m≦N) series-connected energy storage units;
• and
• a DC/DC converter for converting a voltage, output through the first output terminal or the second output terminal depending on switching of the switching unit, into a low voltage, and supplying the low voltage to the sub-module controller.