A method for operation of UPS modules connected in parallel is provided. The method includes: in a case that a UPS system is constructed based on multiple UPS modules connected in parallel, sleeping, based on a system load rate, a predetermined number of UPS modules to control the UPS system to operate at a predetermined efficiency level; controlling UPS modules not being slept in the UPS system to enter into a main-inverter power supply mode or a main-bypass common mode to perform reactive power and harmonic compensation; and waking up the slept UPS modules when the system load rate drops by a predetermined value due to a sudden addition of a load. The UPS modules can be slept or waked up intelligently based on the system load rate in the dynamic online mode, ensuring that the UPS system operates around highest efficiency.

A system architecture and method for enabling hierarchical intelligent control with appropriate-speed communication and coordination of control using intelligent distributed impedance/voltage injection modules, local intelligence centers, other actuator devices and miscellaneous FACTS coupled actuator devices is disclosed. Information transfer to a supervisory utility control is enabled for responding to integral power system disturbances, system modelling and optimization. By extending the control and communication capability to the edge of the HV power grid, control of the distribution network through FACTS based Demand response units is also enabled. Hence an integrated and hierarchical total power system control is established with distributed impedance/voltage injection modules, local intelligence centers, connected other actuator devices, miscellaneous FACTS coupled devices and utility supervisory all networked at appropriate speeds allowing optimization of the total power system from generation to distribution.

According to one embodiment, a voltage converting device includes a DC power source; an inverter generating AC power; an AC component detector configured to detect an AC component of current flowing through a first terminal or a second terminal of the inverter in the DC power source side; and a phase estimator configured to estimate a phase relation between a phase of voltage of the AC power and a phase of current of the AC power based on an amplitude of a specific frequency component contained in a first absolute value signal of the AC component. The AC power generated by the inverter is supplied to a loading device, and an impedance of the loading device at a fundamental of a driving frequency of the inverter is smaller than an impedance of the loading device at an odd-order harmonic of the driving frequency.

The present disclosure relates to a device of monitoring a reactive power compensation system to compensate reactive power, the device including a measurement unit configured to acquire voltage data, current data, and a phase angle from each constituent device, a power performance index calculation unit configured to calculate power performance index data including at least one of power factor data, flicker data, and harmonics data based on the acquired voltage data, current data, and phase angle, and a controller configured to analyze and evaluate the calculated power performance index data based on a preset situation.

A monitoring system includes a capacitor can having one or more capacitors. The monitoring system includes an antenna. The monitoring system includes at least one sensor disposed within the capacitor can and configured to detect an operating characteristic associated with health of the one or more capacitors of the capacitor can. The monitoring system includes a processor configured to receive a first signal from the at least one sensor indicative of the operating characteristic. The processor is configured to send a second signal, via the antenna, indicative of a value of the operating characteristic to a receiving device outside of the capacitor can.

Provided is a method of feeding electric reactive power using a wind farm comprising wind turbines. The wind farm feeds a wind farm active power output and the wind farm active power output includes individual plant active power outputs each generated by one of the wind turbines. The wind farm feeds a wind farm reactive power output into the electrical supply network and the wind farm reactive power output includes individual plant reactive power outputs each generated by one of the wind turbines. The method includes determining a total wind farm reactive power output to be fed in by the wind farm and calculating, for each wind turbine, an individual plant reactive power output to be generated. The individual plant reactive power output is determined depending on the individual plant active power output and depending on the wind farm reactive power output to be fed in.

Systems, methods, and devices are provided to control an electrical component of an electric power distribution system with an intelligent electronic device using electrical measurements from a wireless electrical measurement device located away from the electrical component. One such system includes a capacitor bank on a lateral of an electric power distribution system, a first set of one or more wireless electrical measurement devices that obtain one or more electrical measurements of a first feeder of the electric power distribution system, and a capacitor bank controller. The capacitor bank controller may use the one or more electrical measurements of the first feeder to control the capacitor bank on the lateral.

A transformer assembly for electric grids including: an electric transformer including a magnetic core, a first side including one or more first windings enchained with said magnetic core and adapted to be electrically connected to a first grid section and a second side including one or more second windings enchained with said magnetic core and adapted to be electrically connected to a second grid section; a tap changer operatively associated with said electric transformer to vary the number of turns enchained with said magnetic core for said first windings; a control unit to: acquire input data indicative of an electrical connectivity condition of said second grid section with said second windings; determine whether said transformer is in a load condition or in a no-load condition; and, in a no-load condition, command said tap changer to set a maximum available number of turns for said first windings.

A method of transmitting reactive power between at least one wind turbine and a power system through a transformer connected between the at least one wind turbine and the power system, the wind turbine including a power converter. The method includes a second step of connecting at least one passive device to the transformer and reducing or increasing a reactive power of the power converter of an amount corresponding to the reactive contribution from the passive device.

A device includes an input converter, an output converter, and a controller. The input converter is electrically coupled to an electrical meter and an energy production array. The output converter is electrically coupled to the energy production array and a load. The controller is communicatively coupled to the input converter, the output converter, the energy production array, and the load. The input converter and the output converter are positioned between the electrical meter and the load.