A transformer is provided, which includes a tank having an enclosed volume with an insulating material, the tank including at least one channel extending through the tank, wherein the interior of the at least one channel is separated from the enclosed volume of the tank by a channel wall. A transformer core is provided outside of the enclosed volume, including at least one core leg extending through the tank via the at least one channel. At least one coil is located inside the enclosed volume, the coil being wound about the at least one channel, the tank has an inner wall or outer wall including a weakly-conductive layer, which includes fibers embedded in an impregnating material.

A method for controlling an inverter-based resource (IBR) connected to an electrical grid includes receiving grid parameter(s) and applying a droop function to the grid parameter(s) to determine a power droop signal. Further, the method includes receiving a power reference signal. Moreover, the method includes determining a power command signal as a function of the power droop signal and the power reference signal to allow for a fast response in a power output of the IBR to the grid parameter(s). The method also includes applying power constraint(s) to the power command signal to limit how much the power output of the IBR can be changed due to the grid parameter(s). Further, the method includes determining one or more control commands for the IBR based, at least in part, on the power command signal. Thus, the method includes controlling the IBR based, at least in part, on the power command signal.

A demand response system includes a mobile application of a mobile device that is configured to initiate altering an operating condition of a network device disposed at a site using location based services. A demand response application interface module is configured to enable access between a utility company and the network device to communicate energy management information therebetween. The network device is configured to be remotely altered by each of the demand response application interface module and the mobile application separately based on the location based services and the energy management information. A method of managing a demand response system includes detecting a user being disposed away from a site, detecting energy management information from a utility company associated with the site, and initiating a reduction in energy use at the site in response to the relative location of the user and the energy management information.

A system for managing electrical loads includes a plurality of branch circuits, a sensor system, and control circuitry. The sensor system is configured to measure one or more electrical parameters corresponding to the plurality of branch circuits, and transmit one or more signals to the control circuitry. The control circuitry is configured to determine respective electrical load information in each branch circuit based on the sensor system, and control the electrical load in each branch circuit using controllable elements based on the respective electrical load information. The control circuitry transmits usage information, generates displays indicative of usage information, accesses stored or referencing information to forecast electrical load, and manages electrical load in response to identified events. The control circuitry can associate each branch circuit with reference load information, and disaggregate loads on each branch circuit based on the reference load information and on the electrical load in the branch circuit.

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

An auxiliary power supply device for an inverter with a plurality of power modules connected in parallel is disclosed. The auxiliary power supply device includes: a plurality of soft-start circuits, each coupled to a DC port of a corresponding power module; a plurality of distributed auxiliary power supplies, each having an input terminal coupled to the DC port of the corresponding power module; and a centralized auxiliary power supply having an input terminal coupled to an AC side of the inverter, and an output terminal coupled to a DC side of the inverter. By replacing auxiliary power supplies on the AC sides of all power modules with the centralized auxiliary power supply and omitting soft-start circuits on the AC sides of all power modules, the present invention improves system performance in cost, volume, loss, and electromagnetic compatibility.

A control device (2) of an inverter converts electrical power generated by a solar cell (3) into alternating current power connecting to an electric power system (7). The control device includes: an alternating current voltage sensor (14) sensing a system voltage (Vr) of the electric power system; an MPPT executer (23) controlling a direct current voltage (Vdc) applied to the inverter (1) to cause the electrical power output from the solar cell (3) to be a maximum when the direct current voltage (Vdc) is higher than a lower limit (VL); a direct current voltage lower limit calculator 22 reducing the lower limit (VL) when the system voltage (Vr) is lower than a predetermined voltage; and an electrical power controller (25) controlling reactive power based on the system voltage (Vr), the reactive power being output from the inverter (1).