A double-stage inverter apparatus for energy conversion systems (FIG. 1) and control method thereof, adapted to manage the operations of the on-board booster module so as to optimize the overall electrical efficiency of the system. Furthermore, the method according to the present invention allows the operations of said double-stage inverter to be managed when there is only one input channel, when there are multiple input channels called to operate both in parallel and also when there are multiple input channels called to operate independently from each other.