Abstract: Methods of precisely positioning a rotor of a machine into one or more service positions for the purpose of servicing the machine. In some embodiments, the machine includes A rotor and a stator segmented into multiple removable stator modules. During servicing, a stator-module replacement tool is precisely located in any one or more of multiple service positions corresponding to the multiple stator modules by selectively energizing the machine. In other embodiments, the machine includes a stator and a rotor having multiple removable permanent magnets corresponding respectively to multiple service positions. During servicing, the rotor is precisely located in any one or more of multiple service positions corresponding to the permanent magnets by selectively energizing the machine. A servicing control system is disclosed for controlling the excitation of a machine stator in a manner that effects precise positioning of the rotor into a selected service position.

Abstract: A distributed energy resource (DER) switching system and method for connecting a DER to an electrical power system (EPS) protector, wherein the DER has a reactance-to-resistance ratio higher than the reactance-to-resistance ratio of the EPS protector. The DER switching system includes an input for receiving power from the DER, and an output for providing power from the DER to the EPS protector. The DER switching system is designed to effectively lower the higher reactance-to-resistance ratio of the DER during an over-current fault so that, during the fault, the effective reactance-to-resistance ratio at the output of the DER switching system is lower than the reactance-to-resistance ratio of the EPS protector. The method includes effectively lowering the reactance-to-resistance ratio of the DER by varying the operating state of a switching device in a controlled manner during the fault.

Abstract: A power system for connecting a variable voltage power source, such as a power controller, with a plurality of energy storage devices, at least two of which have a different initial voltage than the output voltage of the variable voltage power source. The power system includes a controller that increases the output voltage of the variable voltage power source. When such output voltage is substantially equal to the initial voltage of a first one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the first one of the energy storage devices. The controller then causes the output voltage of the variable voltage power source to continue increasing. When the output voltage is substantially equal to the initial voltage of a second one of the energy storage devices, the controller sends a signal that causes a switch to connect the variable voltage power source with the second one of the energy storage devices.

Abstract: Methods of precisely positioning a rotor of a machine into one or more service positions for the purpose of servicing the machine. In some embodiments, the machine includes A rotor and a stator segmented into multiple removable stator modules. During servicing, a stator-module replacement tool is precisely located in any one or more of multiple service positions corresponding to the multiple stator modules by selectively energizing the machine. In other embodiments, the machine includes a stator and a rotor having multiple removable permanent magnets corresponding respectively to multiple service positions. During servicing, the rotor is precisely located in any one or more of multiple service positions corresponding to the permanent magnets by selectively energizing the machine. A servicing control system is disclosed for controlling the excitation of a machine stator in a manner that effects precise positioning of the rotor into a selected service position.

Abstract: An energy storage system including a buck-boost DC-DC converter operable so as to minimize switching loses. The system includes a first energy storage device, e.g., a bank of ultracapacitors, and a second energy storage device, e.g., a second bank of electrolytic capacitors. Both first and second energy storage devices are connected to the DC-DC converter. The DC-DC converter is operated in a non-standard manner so as to reduce switching and other losses. In particular, the DC-DC converter may be operated in an alternate buck mode so as to force on a switch S2 through which energy flows from the first energy storage device to the second energy storage device. The switch S2 is forced on for so long as the voltage on the second energy storage device remains within a first operating window.

Abstract: A distributed energy resource (DER) switching system and method for connecting a DER to an electrical power system (EPS) protector, wherein the DER has a reactance-to-resistance ratio higher than the reactance-to-resistance ratio of the EPS protector. The DER switching system includes an input for receiving power from the DER, and an output for providing power from the DER to the EPS protector. The DER switching system is designed to effectively lower the higher reactance-to-resistance ratio of the DER during an over-current fault so that, during the fault, the effective reactance-to-resistance ratio at the output of the DER switching system is lower than the reactance-to-resistance ratio of the EPS protector. The method includes effectively lowering the reactance-to-resistance ratio of the DER by varying the operating state of a switching device in a controlled manner during the fault.

Abstract: An energy storage system including a buck-boost DC-DC converter operable so as to minimize switching loses. The system includes a first energy storage device, e.g., a bank of ultracapacitors, and a second energy storage device, e.g., a second bank of electrolytic capacitors. Both first and second energy storage devices are connected to the DC-DC converter. The DC-DC converter is operated in a non-standard manner so as to reduce switching and other losses. In particular, the DC-DC converter may be operated in an alternate buck mode so as to force on a switch S2 through which energy flows from the first energy storage device to the second energy storage device. The switch S2 is forced on for so long as the voltage on the second energy storage device remains within a first operating window.