Abstract: A system for converting at least one electrical input direct current into an electrical output alternating current comprising M phases and supplied to M output terminals includes N polyphase inverters, connected in parallel, each converting the input direct current into an intermediate alternating current comprising M phases and supplied to M intermediate terminals; N×M first electromagnetic coupling coils, each being connected to a respective intermediate terminal; N×M magnetic cores, each first coil being wound around a respective core. This system comprises N×M second electromagnetic coupling coils, each being connected to a respective first coil and wound around a distinct core from that of the respective first coil. The first and second coils of a same core correspond to a single phase, and generate respective common mode fluxes of opposite directions. Each output terminal is connected to the M second coils of a single phase.