A power system for a marine ship includes a plurality of protection zones, wherein at least two protection zones are coupled to each other via at least one bus-tie converter. Each of the protection zones includes a plurality of direct current (DC) buses and a plurality of power converters. The bus-tie converter includes at least two converter legs coupled by at least one inductor. Each converter leg includes a first branch connected with a snubber circuit by an intermediate switching device. The first branch includes two outer switching devices and at least one inner switching device connected between the two outer switching devices. The snubber circuit includes a combination of a diode, a resistor and a capacitor. A controller controls the operation of the plurality of power converters and the at least one bus-tie converter.