A method for controlling an operation of a converter circuit adapted to regulate power transfer between a first voltage source and a second voltage source includes detecting a first voltage level of the first voltage source and a second voltage level of the second voltage source; calculating a power value based on the detected first voltage level and the detected second voltage level; comparing the calculated power value with a reference power value; and determining switching time of one or more switches in the converter circuit based on a compared result so as to regulate power transfer between the first voltage source and the second voltage source.