It is provided a multi-phase electric drive for use with a multi-phase AC load and the power unit thereof. The multi-phase electric drive includes a multi-phase power transformer with at least one primary winding and a plurality of secondary windings. The primary winding may be electrically connected to a source of multi-phase AC power. Power units may have an input connected with a corresponding one of said plurality of secondary windings and may have a single-phase controllable output to such multi-phase AC load. The power units may be serially connected with respective others of said power units in each phase output line and are connectable to said multi-phase AC load.