A method for controlling a renewable energy power system having at least one renewable energy asset connected to a power grid during a frequency event includes receiving, via a controller, a frequency signal of the power grid. The method also includes determining a time constant for a frequency filter assembly as a function of two or more parameters of the frequency signal. Further, the method includes filtering the frequency signal via the frequency filter assembly using the determined time constant. Moreover, the method includes determining a power command for the at least one renewable energy asset using the filtered frequency signal. In addition, the method includes controlling the at least one renewable energy asset based on the power command.

A method for isolating a fault in an underground power distribution network. The network includes a power line, a plurality of transformers electrically coupled to and positioned along the power line, a first recloser connected to one end of the power line and a second recloser connected to an opposite end of the power line, where each transformer includes an upstream switching device and a downstream switching device, and where power is provided to both ends of the power line through the first and second reclosers and one of the switching devices is a normally open switching device. The method includes detecting overcurrent by some of the switching devices, detecting loss of voltage by some of the switching devices and sending clear to close messages to some of the switching devices to open and close certain ones of the switching devices to isolate the fault.

The present disclosure provides exemplary embodiments of voltage harvesting devices used in power distribution systems, and provides power distribution system architectures utilizing the voltage harvesting devices. Generally, the voltage harvesting devices transform distribution line AC voltages to produce a low wattage output for distribution system communication and control type devices. The voltage harvesting device can operate whether irrespective of the presence of load current.

An electrical load system includes one or more electrical loads, a power transfer switch, and an electronic control system. The power transfer switch is coupled with and can provide power to one or more electrical loads from a first power source or a second power source. The electronic control system evaluates a source impedance of the first source and controls the power transfer switch in response to the source impedance of the first source indicating a fault condition of the first power source that would interrupt power from the first power source to the one or more electrical loads prior to the fault condition disrupting power from the first power source to the one or more electrical loads.

A method for reducing and/or managing energy-related stress in an electrical system includes processing electrical measurement data from or derived from energy-related signals captured by at least one intelligent electronic device (IED) in the electrical system to identify and track at least one energy-related transient in the electrical system. An impact of the at least one energy-related transient on equipment in the electrical system is quantified, and one or more transient-related alarms are generated in response to the impact of the at least one energy-related transient being near, within or above a predetermined range of the stress tolerance of the equipment. The transient-related alarms are prioritized based in part on at least one of the stress tolerance of the equipment, the stress associated with one or more transient events, and accumulated energy-related stress on the equipment. One or more actions are taken in the electrical system in response to the transient-related alarms to reduce energy-related stress on the equipment in the electrical system.

The present disclosure provides exemplary embodiments of voltage harvesting devices used in power distribution systems, and provides power distribution system architectures utilizing the voltage harvesting devices. Generally, the voltage harvesting devices transform distribution line AC voltages to produce a low wattage output for distribution system communication and control type devices. The voltage harvesting device can operate whether irrespective of the presence of load current.

A method for operating a renewable energy power plant comprising a plurality of renewable energy generators, a plurality of power dissipation systems and a battery storage system is provided. The method comprises steps of: monitoring the statuses of the power dissipation systems; performing a ramped active power recovery operation following a voltage deviation, and controlling the battery storage system during the ramped active power recovery operation to absorb power generated by the renewable energy generators in dependence on the monitored statuses of the power dissipation systems.

A buffer circuit and a multiplexer using the buffer are provided. The buffer may selectively operate at a first mode or a second mode. The buffer includes a first signal input terminal, a first signal output terminal, and a path circuit coupled between the first signal input terminal and the first signal output terminal. The path circuit has a voltage source terminal. In response to the buffer operating at the first mode, a first signal transmission path is formed in the path circuit and between the first signal input terminal and the first signal output terminal. The first signal transmission path is disconnected from the voltage source terminal.

Described are systems and techniques for extracting frequency and voltage harmonic transients corresponding to individual load events. Such systems and techniques can be used to make electrical loads aware of the operation of other loads in an electric grid. Thus, awareness is achieved using information derived only from a utility voltage waveform at a load. Also described are systems and techniques for incorporating such awareness into load controllers which allows loads to autonomously meet system level objectives in addition to their individual requirements.

A method includes detecting a fault in a grid coupled to a distribution power network, the distribution power network comprising a distribution feeder, a plurality of distributed energy resources (DERs) coupled to the distribution feeder and a reference point of applicability (RPA) associated with the plurality of DERs, and in response to detecting the fault, determining an error voltage at the RPA, converting the error voltage into an error signal, broadcasting the error signal to the plurality of DERs, and based on the error signal, reducing the error voltage at the RPA by injecting a plurality of currents from the plurality of DERs to the distribution feeder.