An abnormality of a generator provided with a plurality of power supply units is easily detected. Each of the power supply units includes each of output windings L1 to L4, which are wound independently of each other around the single iron core, and each of rectifier circuits 2 to 5. The power supply units produce an integrated output power. Control means 33 to 35 control the rectifier circuits such that an output voltage agrees with a target voltage Vref. In a case where an added up power W becomes a power target value Wref, when the added up current I further increases, a power comparing section 39 reduces the target voltage Vref to prevent the rectifier circuits from outputting power. Further, when the added up current I exceeds a current upper limit ILMT, a gate pulse is stopped.
An apparatus for controlling the operation of power conditioners (10) for supplying the generated power to an external power system such as a commercial power system, in which power conditioners (10) are interconnected to an external power system, the power conditioners (10) are interconnected through information exchange means, at least one of the power conditioners (10) monitors the reverse power flow, and the power conditioners (10) exchange the monitor information with information of the other power conditioners (10), thereby equalizing the outputs of all the power conditioners (10). A generator (42) has armature windings (60), and an inverter circuit (13) of the power conditioner (10) provided for each of the armature windings (60) is controlled by cable or radio.