Uninterruptible power supply

A power system, comprising a main ac supply, an auxiliary generator, a load, and an electronic circuit operatively coupled to the main ac supply auxiliary generator and load;

• wherein the electronic circuit comprises a dc bus, a first uncontrolled rectifier for coupling the main ac supply to the dc bus, a second uncontrolled rectifier for coupling the auxiliary generator to the dc bus, a dc-to-ac inverter operatively coupled to the dc bus for providing ac output power to the load;
• and further comprising a flywheel motor generator and a second inverter interfacing the flywheel motor generator to the electronic circuit, whereby dc bus voltage may be used to start the motor generator for the purpose of storing energy with the flywheel.

A power system, comprising a main ac supply, an auxiliary generator, a load, and an electronic circuit operatively coupled to the main ac supply auxiliary generator and load;

• wherein the electronic circuit comprises a dc bus, a first uncontrolled rectifier for coupling the main ac supply to the dc bus, a second uncontrolled rectifier for coupling the auxiliary generator to the dc bus, a dc-to-ac inverter operatively coupled to the dc bus for providing ac output power to the load;
• and further comprising a dc storage device and a dc-to-dc converter interfacing the dc storage device to the dc bus of the electronic circuit.

A power system, comprising a main ac supply, an auxiliary generator, a load, and an electronic circuit operatively coupled to the main ac supply auxiliary generator and load;

• wherein the electronic circuit comprises a dc bus, a first uncontrolled rectifier for coupling the main ac supply to the dc bus, a second uncontrolled rectifier for coupling the auxiliary generator to the dc bus, a dc-to-ac inverter operatively coupled to the dc bus for providing ac output power to the load;
• and further comprising means for producing a high nominal power factor as seen by the main ac supply and auxiliary generator, wherein the high nominal power factor is at least approximately 0.95.

A power system, comprising a main ac supply, an auxiliary generator, a load, and an electronic circuit operatively coupled to the main ac supply auxiliary generator and load;

• wherein the electronic circuit comprises a dc bus, a first uncontrolled rectifier for coupling the main ac supply to the dc bus, a second uncontrolled rectifier for coupling the auxiliary generator to the dc bus, a dc-to-ac inverter operatively coupled to the dc bus for providing ac output power to the load;
• and further comprising means to provide clamping of surges on the dc bus.

A power system, comprising a main ac supply, an auxiliary generator, a load, and an electronic circuit operatively coupled to the main ac supply auxiliary generator and load;

• wherein the electronic circuit comprises a dc bus, a first uncontrolled rectifier for coupling the main ac supply to the dc bus, a second uncontrolled rectifier for coupling the auxiliary generator to the dc bus, a dc-to-ac inverter operatively coupled to the dc bus for providing ac output power to the load;
• and further comprising means to prevent voltage sagging on the dc bus.