Aspects of the present invention relate to a method of controlling a renewable power plant comprising a plurality of renewable power generators electrically connected by a local network and configured to supply active power to a main network. The method comprises: in response to receiving a signal requesting substantially zero active power supply to the main network: categorizing a generator as power-supplying, and the remaining generators as power-consuming; operating the power-consuming generators to generate no active power and to have their auxiliary systems draw power from the local network; and operating the power-supplying generator to supply active power to the local network such that the plant supplies substantially zero active power to the main network.

Embodiments herein describe operating wind turbines in an offshore park to provide auxiliary power to a local AC grid or to an onshore grid during a grid malfunction. In one embodiment, the offshore park is coupled via a HVDC link to an onshore grid. When the HVDC link is down, a substation in the park includes a backup generator for creating a weak grid for powering auxiliary systems in a pilot turbine. The wind turbines in the park can switch to an auxiliary control system help power the auxiliary systems in the substation and in other turbines. In another embodiment, the offshore park is AC coupled to an onshore grid using a transformer in the substation. The wind turbines can participate in a brown or black start following a grid fault by switching to operating using the auxiliary control system.

A hydraulic fracturing system includes a turbine generator for producing electricity at a well site, the turbine generator producing electrical energy at a voltage. The system also includes an electric pump electrically coupled to the turbine generator and receiving operative power from the turbine generator. The system further includes switch gear arranged between the electric pump and the turbine generator, the switch gear distributing electrical energy from the turbine generator to the electric pump, wherein the voltage remains substantially constant from the turbine generator to the electric pump.

Devices, systems, and methods for measurement of parameters of electric power transmission lines can improve electric power usage, while wireless circuitry can provide communication from field-located devices. Connection to draw electrical power from the transmission line can be distinct from connection to sense line parameters.

A power distribution monitoring system is provided that can include a number of features. The system can include a plurality of monitoring devices configured to attach to individual conductors on a power grid distribution network. In some embodiments, a monitoring device is disposed on each conductor of a three-phase network and utilizes a split-core transformer to harvest energy from the conductors. The monitoring devices can be configured to harvest energy from the AC power grid. In some embodiments, the monitoring devices are configured to draw a ratiometric current to maintain an output resistance that equals an input resistance. Methods of installing and using the monitoring devices are also provided.

A power factor improvement and power generation apparatus using a piezoelectric element may include: a first piezoelectric element having first and second electrodes, and vibrating when voltage is applied from a power line; and a second piezoelectric element having first and second electrodes, and generating electricity in accordance with vibration of the first piezoelectric element. This apparatus is possible to improve a power factor of a power line and generate power using the inherent condenser component, which a piezoelectric element has, instead of a power factor compensation condenser, and it is also possible to generate power.

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.

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 modular system is described which can provide high frequency monitoring of power use and responsive control as well as enabling network connectivity for centralised monitoring and operation. One modular system consists of a communications bus, end caps, and a combination of the modules providing communications, power metering, relay control and battery backup. Each modular system can be configured with a combination of modular units as needed for the application. A combination of bus communication monitoring and tilt detection provides security against external tampering after installation.

A modular system is described which can provide high frequency monitoring of power use and responsive control as well as enabling network connectivity for centralised monitoring and operation. One modular system consists of a communications bus, end caps, and a combination of the modules providing communications, power metering, relay control and battery backup. Each modular system can be configured with a combination of modular units as needed for the application. A combination of bus communication monitoring and tilt detection provides security against external tampering after installation.