A voltage regulation device includes: an input node configured to receive electrical power from an electrical power source; a primary winding electrically connected to the input node; an output node configured to provide electrical power to a load; a shunt winding electrically connected to the output node; a converter configured to provide a compensation current to the shunt winding; and a control system configured to: determine a harmonic compensation signal based on harmonic frequency data; determine a reactive power compensation signal based on a reactive power set point; and control the converter based on the determined harmonic compensation signal and the determined reactive power compensation signal to produce the output compensation signal. The output compensation signal is configured to reduce the one or more harmonic frequency components in a current that flows in the output node and to control an amount of reactive power at the output node.

System for controlling voltage supply to a portion of a distribution grid. The portion of the grid includes a substation providing one or more transformers operable to increase or decrease the voltage supplied to consumers within the portion of the grid. The voltage control system providing a data set can include a previously measured power consumption associated with previously measured values of (a) property(ies) for a portion of the grid, the property(ies) being one of voltage, current, frequency or load, or a combination thereof. The voltage control system can provide a measurement device to measure the property(ies) supplied within the portion of the grid. The voltage control system can provide a processing device to determine from the previously measured values of the property(ies) in the data set a most likely effect of altering the value of the property(ies) from a first value to a second value, on the power consumption.

A method of limiting a total power delivered by a power distribution unit having a plurality of output connectors is disclosed. A configurable power threshold is assigned for each of the output connectors so that a sum of the configurable power thresholds of the output connectors does not exceed a maximum rated power for the power distribution unit. A power level of a given output connector is sensed. A delivery of power by the given output connector is stopped when the power level of the given output connector exceeds the configurable power threshold for the given output connector. Power delivery may be resumed in response to receiving a user command to rearm the given output connector. A power distribution unit adapted to limit its total power delivery is also disclosed.

A power supply for a power line includes a synchronization module having a receiver configured for receiving a clock signal from a satellite-based positioning system and an oscillator configured for generating a periodic signal synchronized to the received clock signal. The power supply includes an inverter module having an inverter configured for supplying an AC voltage to the power line, receiving the periodic signal from the synchronization module, and controlling the inverter using the received periodic signal as a synchronization reference signal for the supplied AC voltage. The power supply further includes a power exchange control module configured for: monitoring an active power flow P from the inverter module to the power line, determining whether the active power flow P satisfies a reverse-flow condition, and when the reverse-flow condition is determined, adapting at least one of a phase and an output voltage of the supplied AC voltage.

A method for controlling active and reactive powers in grid-tied converters having a grid side and a battery side, in which said grid side supplies an alternative current to said converter whereas the battery side receives a direct current from said converter, said method comprising direct active and reactive power control in ABC frame where no transformation is used, and wherein active power is controlled by controlling the battery charging and discharging currents, and reactive power is controlled by controlling the phase shift between power factor correction current and voltage.

The present application concerns a transformer assembly. The transformer assembly includes a step-up transformer, a step-down transformer, and a phase shifting transformer having a source side and a load side connected, respectively, to the step-down transformer and the step-up transformer.

An apparatus for a load tap changer includes a first primary winding electrically connected to a first contact, the first contact configured to connect to one of a plurality of taps in a load tap changer; a second contact, the second contact configured to connect to one of the plurality of taps in the load tap changer; a magnetic core; and a control circuit including: a secondary winding configured to magnetically couple to the first primary winding and the magnetic core; and an electrical network electrically connected to the secondary winding, the electrical network being configured to prevent magnetic saturation of the magnetic core during switching of the first or second contact.

A system and a method for locally controlling delivery of electrical power along the distribution feeder by measuring certain electricity parameters of a distribution feeder line using a substation phasor measurement unit (PMU) electrically coupled to a substation distribution bus at a first node on the feeder line, and at least one customer site PMU electrically coupled to a low voltage end of a transformer at a customer site, wherein the transformer is coupled by a drop line to a second node on the distribution feeder line and the customer site is coupled by another drop line to the transformer, and by controlling at least one controllable reactive power resource and optionally a real power resource connected to the second node or at the customer site. Related apparatus, systems, articles, and techniques are also described.

A configuration for stabilizing an AC voltage grid has a rotating phase-shifter that is configured to exchange reactive power with the AC voltage grid. The configuration is distinguished by a converter which has a grid side for connection to the AC voltage grid and a machine side for connection to the phase-shifter. A method is furthermore taught for stabilizing the AC voltage grid by way of the configuration.

A solar cell power conversion device is disposed between a solar cell and a distribution system. A storage battery power conversion device is disposed between a storage battery and the distribution system. An effective voltage calculation circuit calculates an effective voltage of an AC voltage in the distribution system. Based on the effective voltage, a second control circuit and a fourth control circuit control active power and reactive power output from a first DC/AC conversion circuit and a second DC/AC conversion circuit, respectively. When a change in the effective voltage is caused by an operation of an SVR provided in the distribution system, the second and fourth control circuits control operations of the first and second DC/AC conversion circuits to suppress a change in the reactive power caused by the change in the effective voltage.