Abstract: A power supply system including an uninterruptible power supply (UPS) comprising an input coupled to an AC source and configured to receive input AC power from the AC source and an output configured to provide AC output power to a load, the UPS including a converter coupled to the input, an inverter coupled to the output, and a DC bus coupled between the converter and the inverter, a renewable power source configured to provide DC power derived from a renewable energy source, a first DC/DC converter coupled between the renewable power source and the DC bus and configured to provide DC power derived from the renewable power source to the DC bus, and a controller in communication with the first DC/DC converter and configured to monitor an output power capability of the renewable power source, and to operate the first DC/DC converter to provide DC power derived from the renewable power source to the DC bus based on the output power capability of the renewable power source.

Abstract: An area electric power system includes a number of direct current power sources, and a number of inverters operatively associated with the number of direct current power sources. Each of the number of inverters is structured to provide real power and controlled reactive power injection to detect islanding. An output is powered by the number of inverters. A number of electrical switching apparatus are structured to electrically connect the number of inverters to and electrically disconnect the number of inverters from a utility grid. A number of devices are structured to detect islanding with respect to the utility grid responsive to a number of changes of alternating current frequency or voltage of the output.

Abstract: An area electric power system includes a number of direct current power sources, and a number of inverters operatively associated with the number of direct current power sources. Each of the number of inverters is structured to provide real power and controlled reactive power injection to detect islanding. An output is powered by the number of inverters. A number of electrical switching apparatus are structured to electrically connect the number of inverters to and electrically disconnect the number of inverters from a utility grid. A number of devices are structured to detect islanding with respect to the utility grid responsive to a number of changes of alternating current frequency or voltage of the output.

Abstract: An area electric power system includes a number of direct current power sources, and a number of inverters operatively associated with the number of direct current power sources. Each of the number of inverters is structured to provide real power and controlled reactive power injection to detect islanding. An output is powered by the number of inverters. A number of electrical switching apparatus are structured to electrically connect the number of inverters to and electrically disconnect the number of inverters from a utility grid. A number of devices are structured to detect islanding with respect to the utility grid responsive to a number of changes of alternating current frequency or voltage of the output.

Abstract: An ac-ac power converter system is provided for supplying power to an electrical load. The ac-ac power converter system provides an output voltage having variable amplitude and/or frequency. The ac-ac power converter system includes a boost inductor for applying a discontinuous current to an ac-ac power converter. The ac-ac power converter includes a rectifier circuit comprising of a first set of gate controllable active switches for converting an input ac power to a dc power and an inverter circuit comprising of a second set of gate controllable active switches for converting the dc power to an output ac power. In addition, the ac-ac power converter system includes a switch for switching between a first mode of operation and a second mode of operation.