A power control system may include an uninterruptible power supply (UPS), a display device, load measurement circuitry to determine a load percentage of the UPS, and a controller. The controller may receive the load percentage of the UPS from the load measurement circuitry; monitor the load percentage of the UPS to determine whether the UPS is operating in a nominal load state or an overload state; generate an input overload countdown timer when the UPS is operating in the overload state, where the input overload countdown timer provides an estimated time remaining in the overload state; generate an output overload countdown timer by applying a minimum envelope filter to the input overload countdown timer; and direct the display device to display the output overload countdown timer. Additionally, the minimum envelope filter may be operated in an open-loop or a closed-loop configuration.

Systems and methods for supplying power at a medium voltage from an uninterruptible power supply (UPS) to a load without using a transformer are disclosed. The UPS includes an energy storage device, a single stage DC-DC converter or a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a unidirectional or bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique. The UPS may also include a small filter to remove harmonics in the AC voltage output from the multi-level inverter.

An uninterruptible power supply (UPS) is provided that includes a split direct current (DC) link having a first capacitor coupled between a positive DC link terminal and a first node, and a second capacitor coupled between the first node and a negative DC link terminal. The UPS also includes a rectifier coupled to an input of the split DC link and a controller coupled to the rectifier. The rectifier includes first, second, and third legs, wherein each leg is configured to convert a first alternating current (AC) voltage received from an AC source into a DC voltage to be provided to the split DC link, and a fourth leg configured to balance DC link voltages of the first and second capacitors. The controller is configured to maintain functionality of the rectifier during at least one of a partial utility power outage, a full utility outage, and a failure of at least one of the first, second, third, and fourth legs.

A line module for use in a network device includes a plurality of circuits; and a power module connected to the plurality of circuits, and to a first Power Distribution Unit (PDU) and a second PDU, wherein the first PDU and the second PDU provide power distribution by different feeds, wherein the power module is configured to initiate a shutdown procedure when one or more of i) a current drawn from any feed equals or exceeds a first current threshold, and ii) an aggregate current drawn from all feeds equal or exceeds a second current threshold.

A line module for use in a network device includes a plurality of circuits; and a power module connected to the plurality of circuits, and to a first Power Distribution Unit (PDU) and a second PDU, wherein the first PDU and the second PDU provide power distribution by different feeds, wherein the power module is configured to initiate a shutdown procedure when one or more of i) a current drawn from any feed equals or exceeds a first current threshold, and ii) an aggregate current drawn from all feeds equal or exceeds a second current threshold.

A vehicle control unit (e.g., a control unit for an automobile) receives feedback from an intelligent voltage/current sensor and a DC/DC controller. The DC/DC controller comprises a first switch for controlling power from a primary power source (e.g., low voltage power supplied from a high voltage battery). The intelligent voltage/current sensor senses power output from the primary power source. The vehicle control unit processes feedback from the intelligent voltage/current sensor and/or the DC/DC controller to determine if a failure has occurred in the primary power source. In response to determining the failure in the primary power source, the vehicle control unit disables the power from the primary power source using a second switch (e.g., a switch in a relay).

An apparatus for covering an open top of a transportation trailer container, such as a chip train carrying wood chips, is provided. A flexible cover (e.g. tarp) may be deployed and retracted using a roller moved overtop of the container using pivotable arms. An electrically powered covering mechanism automatically deploys and retracts the cover. The covering mechanism is powered by a supercapacitor, which is charged when connected to an external power source. A charging control circuit can selectably allow or inhibit charging of the supercapacitor depending on power demands of other electrical loads.

A power management system for managing power of a climate control unit (CCU) configured to be used with at least one of an electric vehicle, a trailer, or a transport container and at least partially powered by the electric vehicle is disclosed. The system includes a power distribution system that includes a power input, a power distributor electrically connected to the power input, a fault detecting and isolating circuit electrically connected to the power input, and a connection point for receiving the CCU. The connection point is electrically connected to the fault detecting and isolating circuit. A power controller is electrically connected to the power distribution system. The power controller includes a processor and a memory.

In one implementation, a communications apparatus includes a communications circuit including a first communications system configured to communicate with a first communications network over a first communications medium; a second communications system configured to communicate with the first communications network over a second communications medium; and a communications port configured to communicate with a second communications network. The communications apparatus can further include a power circuit that includes a first power system configured to power the communications apparatus with a first power source; and a second power system configured to power the communications apparatus with a second power source. The communications apparatus can further include a processing system configured to be powered by the power circuit and selectively control communications flows between the communications port and at least one of the first communications system and the second communications system.

In one implementation, a communications apparatus includes a communications circuit including a first communications system configured to communicate with a first communications network over a first communications medium; a second communications system configured to communicate with the first communications network over a second communications medium; and a communications port configured to communicate with a second communications network. The communications apparatus can further include a power circuit that includes a first power system configured to power the communications apparatus with a first power source; and a second power system configured to power the communications apparatus with a second power source. The communications apparatus can further include a processing system configured to be powered by the power circuit and selectively control communications flows between the communications port and at least one of the first communications system and the second communications system.