Regenerative AC/DC/AC power converter for a plurality of motors

An inverter apparatus operative with a plurality of motors comprising:

• forward converting means for converting an input from an AC power supply on an AC input side into a DC voltage output on a DC output side, said forward converting means including a diode bridge;
• regenerative power converting means for inversely converting said DC voltage output from the forward converting means into an AC voltage and returning said AC voltage to the AC power supply, the regenerative power converting means being coupled to said forward converting means and having a plurality of first circuit arms, each first circuit arm comprising a parallel connection of a switching element and a diode, operation of said plurality of first circuit arms being controlled by a controlling means;
• and
• a plurality of inversely converting means, each of which is coupled to said DC output side of said forward converting means and said regenerative power converting means;
• said plurality of inversely converting means each having a plurality of second circuit arms, each second circuit arm comprising a parallel connection of a switching element and a diode, and operation of said plurality of inversely converting means each being independently controlled;
• said forward converting means designed to permit operation of each of the plurality of inversely converting means under a full motor load;
• said regenerative power converting means designed to return power to the AC power supply when the plurality of motors all operate in complete regenerative mode;
• whereby
• said diode bridge and said regenerative power converting means operate as a converter common to said plurality of inversely converting means and said plurality of inversely converting means are operative to independently output arbitrary voltages and frequencies, to control said plurality of motors.