Two generation systems 3, 8 each including inverter 8 are switched over between series connection and parallel connection by switching section 5. Reference waveform signals are mutually communicated between the two generation systems through communication lines 6. When a phase difference between these two reference waveform signals is within a predetermined range, the inverters are driven to generate an output alternating current. One of the conduction angles of thyristors 3a, 3a in two converters 3, 3 which is larger than the other is inputted to a deviation detector 42. Based on a deviation of the conduction angle inputted from a target conduction angle, an updated target rotational speed is set in a calculator 44. A throttle controller 48 controls a throttle opening angle so that an actual rotational speed converges into the target rotational speed. A ground fault is judged based on a potential difference across one node point in a first arm, connected to the earth and the other node point in a second arm of a resistance bridge provided across a pair of output terminals of either one of the inverters.

Systems and methods for adjusting outputs of dynamoelectric devices, such as alternators, are provided. The outputs of the dynamoelectric devices may be balanced to facilitate load sharing among the devices. The outputs may be balanced by monitoring field signals associated with the dynamoelectric devices and controlling the field voltages of the devices. The outputs may also be adjusted to supply the load in dissimilar proportions.

A rotary electric machine having an armature winding that includes three first phase-windings that form a .DELTA.-connection winding having output ends and three second phase-windings that are respectively connected in series to the output ends to form a star-connection three-phase winding having output ends connected to a rectifier unit.

An improved three-phase bridge inverter DC link converter power circuit for a portable generator, preferably the generator system described in U.S. Pat. No. 5,625,276 to Scott et al. Dual voltage and variable frequency inverter designs and improved converter designs are disclosed. Embodiments of the present invention avoid a capacitor induced center voltage drift problem found in certain prior art inverter designs.

The present invention relates to a six-phase generator for a motor vehicle having two three-phase systems displaced with respect to one another by 30.degree., the phase windings of one of the three-phase systems being positioned in a wye connection and the phase windings of the other three-phase system being positioned in a delta connection.