Abstract: Methods and apparatus provide for: a first DC bus operating to support a first DC voltage potential and for connecting to a DC input of a motor driver inverter circuit; a motor emulator circuit operating to emulate a polyphase motor and including polyphase output terminals for connecting to a polyphase output of the motor driver inverter circuit; a second DC bus operating to support a second DC voltage potential to a DC input of the motor emulator circuit; and a bi-directional DC-DC power supply coupled between the first and second DC busses, and operating to both: (i) add voltage potential to the first DC voltage potential to produce the higher, second DC voltage potential on the second DC bus, and (ii) subtract voltage potential from the second DC voltage potential to produce the lower, first DC voltage potential on the first DC bus.

Abstract: Methods and apparatus provide for: a first DC bus operating to support a first DC voltage potential and for connecting to a DC input of a motor driver inverter circuit; a motor emulator circuit operating to emulate a polyphase motor and including polyphase output terminals for connecting to a polyphase output of the motor driver inverter circuit; a second DC bus operating to support a second DC voltage potential to a DC input of the motor emulator circuit; and a bi-directional DC-DC power supply coupled between the first and second DC busses, and operating to both: (i) add voltage potential to the first DC voltage potential to produce the higher, second DC voltage potential on the second DC bus, and (ii) subtract voltage potential from the second DC voltage potential to produce the lower, first DC voltage potential on the first DC bus.

Abstract: Methods and apparatus for achieving a system, including: a polyphase machine having a plurality of sets of polyphase windings, each of the respective windings of a first of the sets of polyphase windings being inductively linked to one of each of the respective windings of the remaining sets of polyphase windings; a polyphase inverter operable to receive power from the windings of the first set and to produce a polyphase output; and a plurality of single-phase inverters, each operable to receive power from the windings of a respective one of the remaining sets and to produce a single-phase output, wherein each of the respective phases of the polyphase output may be coupled in series or parallel with one of the respective single-phase outputs to produce an aggregate polyphase output.

Abstract: Uninterruptible power supply apparatus which provides for supplying ac power to equipment even if and when the primary ac power is interrupted is disclosed and comprises an ac to dc converter connected to receive the primary ac power. The output of the ac to dc converter is applied to a dc power source. The resultant output of the ac to dc converter and the dc power source is provided as a dc input to a dc to ac inverter. The dc to ac inverter comprises an output transformer having a center-tapped primary. A first switching device is connected between a first end of the center-tapped primary and the negative terminal of the dc input to provide power pulses to one-half of the center-tapped primary. A second switching device is connected between a second end of the center-tapped primary and the negative terminal of the dc input to provide power pulses to the remaining half of the center-tapped primary.