Abstract: Aspects and embodiments described herein are directed to power interface devices and methods. In one aspect, a method for controlling a microgrid is provided. The microgrid includes a power interface device coupled to one or more microgrid elements comprising power sources and loads. The method includes determining, by the power interface device, a mode of operation of the microgrid, determining a power load of the one or more microgrid elements, and based on the mode of operation of the microgrid and the power load of the one or more microgrid elements, adjusting, by the power interface device, a frequency of a voltage of the power interface device to control the one or more microgrid elements.

Abstract: A current control circuit (208) for a power converter (200) to control the switching thereof, wherein the current control circuit comprises a digital controller (210) using a logical input signal (226) to produce a logical control signal (212) with a fixed fundamental frequency for the power converter.

Abstract: An uninterruptible power supply (UPS) system (100) comprises a plurality of UPS units (UPS-1, UPS-2) connected in parallel. The controllers (130) of the units are programmed to implement a voltage calibration procedure and a current calibration procedure, in order that measurements of voltage and current made by sensors within the different units will agree. In the current calibration procedure, the load is disconnected (302) while one of the units is selected as a master and operates in a voltage control mode (VCM) (Steps 304-308). Each other unit is selected in turn and operated in a current control mode (310, 312). Current measurements made in the master unit are communicated (314) via a data bus to the selected unit and compared (316) with measurements made in the unit itself. The unit adapts its current sensing gains to match the master unit.

Abstract: Aspects and embodiments described herein are directed to power interface devices and methods. In one aspect, a method for controlling a microgrid is provided. The microgrid includes a power interface device coupled to one or more microgrid elements comprising power sources and loads. The method includes determining, by the power interface device, a mode of operation of the microgrid, determining a power load of the one or more microgrid elements, and based on the mode of operation of the microgrid and the power load of the one or more microgrid elements, adjusting, by the power interface device, a frequency of a voltage of the power interface device to control the one or more microgrid elements.

Abstract: Disclosed is an uninterruptable power supply comprising a switchable input power converter having an input operable to receive a supply power network voltage, the power network voltage being subject to fluctuations which may give rise to a disturbance to any load connected to the power network; and a voltage regulation circuit for controlling the switchable input power converter, thereby regulating its output. The voltage regulation circuit senses the power network voltage; and causes the uninterruptable power supply to generate from the sensed power network voltage a compensatory reactive current indicative of the voltage fluctuations on the power network voltage. The compensatory reactive current is used to compensate for the voltage fluctuations on the power network voltage.

Abstract: A current control circuit (208) for a power converter (200) to control the switching thereof, wherein the current control circuit comprises a digital controller (210) using a logical input signal (226) to produce a logical control signal (212) with a fixed fundamental frequency for the power converter.

Abstract: An uninterruptible power supply (UPS) system (100) comprises a plurality of UPS units (UPS-1, UPS-2) connected in parallel. The controllers (130) of the units are programmed to implement a voltage calibration procedure and a current calibration procedure, in order that measurements of voltage and current made by sensors within the different units will agree. In the current calibration procedure, the load is disconnected (302) while one of the units is selected as a master and operates in a voltage control mode (VCM) (Steps 304-308). Each other unit is selected in turn and operated in a current control mode (310, 312). Current measurements made in the master unit are communicated (314) via a data bus to the selected unit and compared (316) with measurements made in the unit itself. The unit adapts its current sensing gains to match the master unit.