A point-of-sale (POS) device includes a processor, a battery, a transaction object reader, a printer with a printer controller, and optionally a temperature sensor. The processor determines a present power discharge capability rate of the battery, optionally based on a temperature measured by the temperature sensor. The processor also calculates a first estimated power draw rate based on a first setting value for at least one of the components of the POS device, such as the printer. If the first estimated power draw rate is dangerously close to the present power discharge capability rate of the battery, a second estimated power draw rate is calculated based on a second setting value for the one or more components. If the second estimated power draw rate is no longer dangerously close to the present power discharge capability rate of the battery, the components are set to the second settings value.

A point-of-sale (POS) device includes a processor, a battery, a transaction object reader, a printer with a printer controller, and optionally a temperature sensor. The processor determines a present power discharge capability rate of the battery, optionally based on a temperature measured by the temperature sensor. The processor also calculates a first estimated power draw rate based on a first setting value for at least one of the components of the POS device, such as the printer. If the first estimated power draw rate is dangerously close to the present power discharge capability rate of the battery, a second estimated power draw rate is calculated based on a second setting value for the one or more components. If the second estimated power draw rate is no longer dangerously close to the present power discharge capability rate of the battery, the components are set to the second settings value.

A power supply device which is used as a backup power supply, including a power supply side acquisition unit that acquires information related to a position of the power supply device.

Techniques and apparatus presented herein are directed to improvements in maintaining voltage and frequency stability of an electric power delivery system. To do so, model predictive control (MPC) may be used. Input data may be obtained for a sampling period and may include a current system state. The MPC may predict an initial trajectory of the input data, output data, and a state of the system for a prediction period. The MPC may linearize the output and state trajectories and determine an updated input trajectory based at least in part on the linearized output trajectory. The MPC may determine control inputs to the system which achieve the updated input trajectory for a control period. The MPC may transmit control signals based at least in part on the control inputs to equipment associated with the input data.

A controllable electrical outlet may comprise a resonant loop antenna. The resonant loop antenna may comprise a feed loop electrically coupled to a radio-frequency (RF) communication circuit and a main loop magnetically coupled to the feed loop. The controllable electrical outlet may comprise one or more electrical receptacles configured to receive a plug of a plug-in electrical load and may be configured to control power delivered to the plug-in electrical load in response to an RF signal received via the RF communication circuit. The RF performance of the controllable electrical outlet may be substantially immune to devices plugged into the receptacles (e.g., plugs, power supplies, etc.) due to the operation of the resonant loop antenna. For example, degradation of the RF performance of the controllable electrical outlet may be less when the controllable electrical outlet includes the resonant loop antenna rather than other types of antennas.

A device includes an input converter, an output converter, and a controller. The input converter is electrically coupled to an electrical meter and an energy production array. The output converter is electrically coupled to the energy production array and a load. The controller is communicatively coupled to the input converter, the output converter, the energy production array, and the load. The input converter and the output converter are positioned between the electrical meter and the load.

The invention discloses an islanding detection method in DC microgrids based on MPPT trapezoidal voltage disturbance. The steps are as follows: start the MPPT strategy; set the starting signal threshold of disturbance; measure the output current of PVA at the maximum power; calculate the same environmental factor of PVA with different capacities under the same light intensity and temperature in real time; when the environmental factor is greater than the starting signal threshold of the disturbance, periodic trapezoidal disturbance is carried out to the PVA port voltage reference; if the PCC voltage Upcc exceeds the threshold set by the passive method, it is judged as islanding; otherwise, it is judged whether the change rule of Upcc is consistent with the change rule of the calculated PCC voltage Upccp under the trapezoidal disturbance; If it is consistent, it is judged as islanding; otherwise, it is pseudo islanding.

Systems and methods for managing power on an electric power grid including a server for communicating IP-based messages over a network with distributed power consuming devices and/or power supplying devices, the IP-based messages including information relating to activities by the power consuming devices and/or the power supplying devices; and wherein the information is transformed by the system into settlement grade data corresponding to the activities of the power consuming devices and/or the power supplying devices.

Systems and methods for managing power on an electric power grid including a server for communicating IP-based messages over a network with distributed power consuming devices and/or power supplying devices, the IP-based messages including information relating to activities by the power consuming devices and/or the power supplying devices; and wherein the information is transformed by the system into settlement grade data corresponding to the activities of the power consuming devices and/or the power supplying devices.

A power control device for an electrically powered appliance may selectively switch off one 110 volt input (of two separate 110 volt input lines) of a 220 volt power supply to the appliance during certain periods of operation, in response to a demand-response request. This may adjust operation of one or more components of the appliance, thus adjusting an amount of power consumed by the appliance. A determination of which one, of the two, 110 volt input lines to be switched off may be made based on an analysis of the amount of power consumed by each of the two 110 volt input lines during operation of the appliance. The power control device may be provided at any point between the electrically powered appliance and a power distribution panel distributing power from an external source.