A system and method for determining seasonal energy consumption with the aid of a digital computer is provided. Through a power metering energy loads for a building situated in a known location are assessed as measured over a seasonal time period. Outdoor temperatures for the building are assessed as measured over the seasonal time period through a temperature monitoring infrastructure. A digital computer comprising a processor and a memory that is adapted to store program instructions for execution by the processor is operated, the program instructions capable of: expressing each energy load as a function of the outdoor temperature measured at the same time of the seasonal time period in point-intercept form; and taking a slope of the point-intercept form as the fuel rate of energy consumption during the seasonal time period.

A method for operating an electric island power network having a renewable energy generation plant, a conventional energy generation plant, an energy store, and an energy consumer, includes: defining first operating parameters for the network for when a frequency and/or voltage of the network is outside defined limits; operating the network using the first operating parameters causing the frequency and voltage of the network to both be within the defined limits; defining second operating parameters for the network after the expiration of a defined time span over which the frequency and voltage have remained within the defined limits, the second operating parameters being defined such that operating the network using the second operating parameters causes the network to operate cost-optimally. If verified that the second operating parameters ensure that the frequency and voltage remain within the defined limits, operation using the second operating parameters is maintained. Otherwise, it is discontinued.

Provided are energy device control systems for distributed grid subsystem that control a first power demand of a plurality of appliances. The control system comprises a graphical user interface configured to accept a user input indicative of a first demand and dynamic allocation flexibility associated with the a respective energy device; a communication interface configured to aggregate dynamic allocation values from a plurality of system nodes including at least the user input indicative of a first demand and the dynamic allocation flexibility; and at least one processor programmed to: generate a learning model for evaluating dynamic future allocation with future energy execution prediction, wherein the dynamic future allocation includes at least energy operational information based on a categorization of energy usage at a plurality of respective energy devices; and trigger energy generation on the energy grid at respective generator nodes according to the learning model and dynamic projections.

A power grid restoration system includes a hybrid power plant that provides electrical power to a power grid. The hybrid power plant includes a power plant that generates electrical power with a power drive. A battery energy storage system, which receives and stores electrical power from the power plant, releases the electrical power during block loading of the power grid. A controller couples to the power plant and to the battery energy storage system. The controller controls charging of the battery energy storage system with the power plant and controls the release of a block load of electrical power from the battery energy storage system and the power plant while block loading the power grid during a black grid restoration.

A method and a system for switching from grid-connected to grid-disconnected, and a power conversion system are provided. The method includes determining whether a power grid is abnormal based on a power grid parameter obtained when a PCS is grid-connected and operates in a current source mode, turning off a switching cabinet if the power grid is abnormal, switching from a current source mode to a voltage source mode, sending a command to instruct a grid-connected/grid-disconnected switch to switch from a grid-connected loop to a grid-disconnected loop, controlling an output parameter to smoothly transit from an abnormal parameter value recorded when the power grid is abnormal to a rated parameter value, and supplying power to a load according to the rated parameter value. In this way, seamless switching from grid-connected to grid-disconnected can be achieved, thereby ensuring stability of power supply.

In an embodiment, an off-grid phase splitter includes: a first input port and a second input port that are separately connected to a power supply; a first output port and a second output port that provide a second voltage, and the second output port and a third output port provide a third voltage; a first capacitor connected between the first output port and the second output port; a second capacitor connected between the second output port and the third output port; a first switch circuit and a second switch circuit connected in series to form a first node between the first input port and the second input port, where the first switch circuit and the second switch circuit are unidirectionally switched on in opposite directions,; and an inductor connected between the first node and the second output port.

Systems and methods are described herein to accommodate different settings associated with a converter-based electric power generator and an inverter-based electric power generator for electric power generation within an electric power delivery system. The electric power delivery system may provide electric power generated by a bulk electric system to the loads via distributed substations using a first operating frequency. Moreover, the distributed substations may include inverter-based electric power generators to supply the electric power demand of downstream loads in an islanded configuration. That said, the inverter-based electric power generators may supply the electric power using a second frequency that is higher than the first frequency. Protective systems, positioned downstream from the distributed substations, may use different settings associated with the bulk electric system or the inverter-based electric power generators based on detecting the frequency of the supplied electric power.

A distributed power harvesting system including multiple direct current (DC) power sources with respective DC outputs adapted for interconnection into a interconnected DC power source output. A converter includes input terminals adapted for coupling to the interconnected DC power source output. A circuit loop sets the voltage and current at the input terminals of the converter according to predetermined criteria. A power conversion portion converts the power received at the input terminals to an output power at the output terminals. A power supplier is coupled to the output terminals. The power supplier includes a control part for maintaining the input to the power supplier at a predetermined value. The control part maintains the input voltage and/or input current to the power supplier at a predetermined value.

An electric power delivery system may include a number of electric power generators and loads distributed across a number of islands (e.g., branches). The electric power delivery system may also include reactors between each two islands of the electric power delivery system that may allow current flow between the islands. However, excessive current flow across the reactors may cause system failure and is undesirable. Accordingly, systems and methods are described to control reactive power and active power generation and consumption of the electric power delivery system to reduce (e.g., minimize) the current flow across the reactors.

A control system and method for an inverter-based resource device provided in a synchronous power grid. The control system includes at least one inverter based resource device connected to an electrical power system, and a controller module. The inverter based resource device includes a reference power Pref, a combination module and a transfer function. The inverter based resource device injects modulated power into the power system. The power system (which is represented by a transfer function in the control system) receives an undesirable forced oscillation, which is connected to a measuring device. A controller module processes the measured output and provides a control signal to the inverter based resource device. The controller is arranged to suppress a forced oscillation detected in the power system.