A single phase grid correction system for correcting the power factor of an electrical power grid. The grid has a generator, transmission lines connecting the generator to distribution nodes, feeder lines radiating from each node, and groups of consumers connected to each feeder line. A capacitor bank is located at a number of consumer's premises, indoors, either beside or forming part of the consumer's normal single phase electric panel. A set of remotely controlled switches at the consumer's premises permits the capacitor banks to be switched in and out of grid connection and also allows non-essential high energy consuming loads, not necessarily inductive, to be switched on and off the grid. The grid correction systemic are widely distributed at consumer's premises throughout the grid. By remotely controlling the switches, the utility operator can switch capacitor banks at selected consumer premises in or out of the grid to provide or remove reactive power as needed, and can also selectively remove load from the grid to reduce the likelihood of sudden uncontrollable load shedding.

A system and method for controlling a grid-connected reactive power compensation inverter. The system uses a combination of feedforward and feedback controls to compute a reference voltage signal based on sensor-measured voltages and currents, where the reference voltage signal is used to control the inverter switches. The disclosed method modifies a cross-couple feedforward signal used in the reference voltage calculations, where the modified cross-couple signal includes a combination of both reference and actual currents, and the modified control scheme reduces the DC-link voltage overshoot experienced during a capacitive overload event while still providing the required reactive power and maintaining grid system stability.

A method, apparatus, system and computer program is provided for optimizing and controlling volt-amperes reactive on an electrical control system. System-level and local-level measurements are determined and analyzed to prioritize and optimize which VAR adjusters are adjusted.

The present disclosure provides a method and a device for controlling an active distribution network, relating to the field of power system operation and control technology. The method includes: creating a power loss objective function; determining first power flow equations; obtaining second power flow equations by performing linearization on the first power flow equations; determining a sub-scale adjustment model of a transformer; obtaining a linearized model of the transformer by performing linearization on the sub-scale adjustment model; obtaining control parameters by solving the power loss objective function according to the second power flow equations, the linearized model of the transformer, an operation constraint of the continuous reactive power compensator, an operation constraint of the grouping switching capacitor, an operation constraint of the distributed generator and a safety operation constraint in the active distribution network, such that the active distribution network is controlled by the obtained parameters to minimize power loss.

Systems and methods for an edge of network voltage control of a power grid are described. A system includes a distribution power network, a plurality of loads (at or near an edge of the distribution power network), and a plurality of shunt-connected, switch-controlled volt ampere reactive (VAR) sources also located at the edge or near the edge of the distribution power network where they may each detect a proximate voltage. The VAR source can determine whether to enable a VAR compensation component therein based on the proximate voltage and adjust network VAR by controlling a switch to enable the VAR compensation component. Further still, each of the VAR sources may be integrated within a customer-located asset, such as a smart meter, and a multitude of such VAR sources can be used to effectuate a distributed controllable VAR source (DCVS) cloud network.

In one embodiment, a computing device determines real and reactive power flows at a transformer at a given time, and computes, based on the real power and reactive power flow at the transformer, an amount of reactive power adjustment to produce a desired voltage differential across the transformer. The computing device may then adjust the reactive power flow from a secondary side of the transformer at substantially the given time based on the computed amount.

A topology of composite cascaded high-voltage and low-voltage modules is provided. It includes at least one high-voltage module, at least one low-voltage module, at least one local control circuit and at least one DC-to-DC module. At least one high-voltage module is connected with at least one low-voltage module in cascade manner. At least one local control circuit outputs at least one signal to at least one high-voltage driving circuit and at least one low-voltage driving circuit. An input of at least one DC-to-DC module is connected with two ends of a low-voltage bus capacitor, for receiving a low-voltage DC bus voltage and converting the low-voltage DC bus voltage into a DC output voltage, so as to provide one or more of at least one high-voltage driving circuit, at least one low-voltage driving circuit and at least one local control circuit with a power supply.

A method, apparatus, system and computer program is provided for optimizing and controlling volt-amperes reactive on an electrical control system. System-level and local-level measurements are determined and analyzed to prioritize and optimize which VAR adjusters are adjusted.

A topology of composite cascaded high-voltage and low-voltage modules is provided. It includes at least one high-voltage module, at least one low-voltage module, at least one local control circuit and at least one DC-to-DC module. At least one high-voltage module is connected with at least one low-voltage module in cascade manner. At least one local control circuit outputs at least one signal to at least one high-voltage driving circuit and at least one low-voltage driving circuit. An input of at least one DC-to-DC module is connected with two ends of a low-voltage bus capacitor, for receiving a low-voltage DC bus voltage and converting the low-voltage DC bus voltage into a DC output voltage, so as to provide one or more of at least one high-voltage driving circuit, at least one low-voltage driving circuit and at least one local control circuit with a power supply.

In a coiled tubing assembly for use in a wellbore, the tubing assembly uses longitudinally spaced apart clamping members to clamp two or more coiled tubing members alongside one another. Each clamping member includes a clamping portion extending circumferentially about each coiled tubing member so as to be rotatable in relation thereto, and a connecting portion joined between the clamping portions. A longitudinal positioning element is fixed relative to one of the tubing members in association with each clamping member such that the clamping member remains pivotal relative to the positioning element and the tubing members upon which it is fixed. The longitudinal positioning element thus only restricts the respective clamping assembly in the longitudinal direction along the tubing members without restricting relative twisting between the tubing members.