The invention provides a method and system for operating an inverter based distributed power generation source with energy storage system, as a Flexible AC Transmission System (FACTS) device—a STATCOM. The inverter based distributed power generation source can provide reactive power compensation, voltage regulation, damping enhancement, stability improvement and other benefits provided by FACTS devices. These STATCOM functions are provided when the said energy storage based distributed power generation source is doing at least one of: i) not exchanging active power with said power grid system, or ii) exchanging active power less than a maximum inverter capacity with said power grid system. The present invention thus provides a technological improvement that opens up a new set of applications and potential revenue earning opportunities for energy storage based distributed power generation sources other than simply from exchanging (injecting or absorbing) active power.

A power conversion device includes: a power converter connected to an AC grid to which a load is connected; and a control circuit. The control circuit includes a harmonic compensation unit that includes a current command generation unit and a limit coefficient calculation unit and compensates for harmonic current contained in load current. The current command generation unit generates compensation current desired values for respective frequency components, and corrects the compensation current desired values using corresponding limit coefficients, to generate compensation current commands for respective frequency components. The limit coefficient calculation unit calculates each limit coefficient, on the basis of the compensation current desired value for each frequency component, and maximum voltage and maximum current that the power converter can output.

Systems and methods are described for active harmonics cancellation. A wireless charging apparatus includes a wireless-power transfer circuit comprising a wireless-power transfer coil configured to generate or couple to a magnetic field to transfer or receive power and a plurality of tuning capacitors electrically coupled to the wireless-power transfer coil. The apparatus also includes a power converter circuit electrically coupled to the wireless-power transfer circuit. Additionally, the apparatus includes a signal generation circuit different from the power converter circuit and electrically coupled to one or more nodes between capacitors of the plurality of tuning capacitors. The signal generation circuit is configured to generate and inject a signal into the wireless-power transfer circuit at the nodes between the capacitors. The signal generation circuit includes a rejection filter tuned to an operating frequency of the wireless-power transfer coil.

Systems and methods are described for active harmonics cancellation. A wireless charging apparatus includes a wireless-power transfer circuit comprising a wireless-power transfer coil configured to generate or couple to a magnetic field to transfer or receive power and a plurality of tuning capacitors electrically coupled to the wireless-power transfer coil. The apparatus also includes a power converter circuit electrically coupled to the wireless-power transfer circuit. Additionally, the apparatus includes a signal generation circuit different from the power converter circuit and electrically coupled to one or more nodes between capacitors of the plurality of tuning capacitors. The signal generation circuit is configured to generate and inject a signal into the wireless-power transfer circuit at the nodes between the capacitors. The signal generation circuit includes a rejection filter tuned to an operating frequency of the wireless-power transfer coil.

[Object] As compared with the case where a device supplies power to an electric line regardless of an index regarding the capacity of power in an electric path, the device may supply the power to the electric line according to the content of supply suitable for the electric path.

[Solution] A power control system includes an acquisition unit that acquires capacity information on capacity of power in an electric path through which power supplied from a power plant passes before the power is received by a device, and a control unit that performs control on, based on the capacity information, supply of power from the device to an electric line through which the power supplied from the power plant passes before the power is received by the device.

[Object] On the basis of a limit of an operation of a control unit that is connected to a power-receiving path of a converting unit, is electrically parallel with the converting unit, and controls apparent power in the power-receiving path of the converting unit, the operation of the control unit is controlled.

[Solution] A power control system includes: an acquisition section that acquires control unit information related to a limit of an operation by a control unit provided for a heat pump system that regulates temperature and/or humidity; and a control section that controls an operation of the control unit on the basis of the control unit information. The control unit is connected to a power-receiving path of a converting unit that converts received power and supplies the converted power to a load used for the regulating. The control unit is electrically parallel with the converting unit. The control unit controls apparent power in the power-receiving path.

Distributed grid intelligence can enable a modular power grid. Multiple consumer nodes are coupled to a same point of common coupling (PCC). Local power sources are coupled to the PCC. None of the power sources has sufficient generation capacity alone to meet peak demand of the multiple consumer nodes of the grid segment. The grid segment includes multiple control nodes to control distribution of power from the power sources to the multiple consumer nodes based on power demand from the multiple consumer nodes and based on operation of the other power sources. Thus, consumer nodes can share power generated locally, but operate independently without the need for central management or a central power plant, and different independent segments can be coupled to each other to expand the grid network.

Distributed grid network intelligence enables intelligent local energy storage backup control. A consumer node includes a local energy storage system. A distributed control node for the consumer node monitors local power demand and local energy generation. The control node calculates an interface operation for accessing energy from the local energy storage or charging the local energy storage, based on the local power demand and the local energy generation. The control node triggers a local power converter to execute the interface operation with the local energy storage.

The embodiments herein relate to a system (100) for controlling a 3-phase transformer device (101, T1, T2, T3). The system (100) comprises the 3-phase transformer device (101, T1, T2, T3) which comprises a primary side and an adjustable secondary side. The system (100) comprises at least one voltage sensor (S1, S2, S3) adapted to sense voltage at the primary side. The system (100) comprises a current sensor (S4) adapted to sense current through the adjustable secondary side, and a resistor (R1) connected in series with the current sensor (S4) at the adjustable secondary side. The system comprises a controller (103) adapted to obtain sensor data indicating the sensed voltage and the sensed current, and to control a parameter associated with the adjustable secondary side of the 3-phase transformer device (101, T1, T2, T3) based on the obtained sensor data.

A control device for an active filter connected in parallel with a load at an installation point with respect to an AC power supply provided in a power system includes a harmonic voltage detector to detect an m-order harmonic voltage (m is an integer not less than two) included in a voltage of the installation point, a phase corrector to correct a phase of the detected m-order harmonic voltage in accordance with whether an m-order harmonic impedance when an AC power supply side is seen from the installation point is capacitive or inductive, a command value generator to generate a first compensation command value for compensating for the m-order harmonic voltage included in the voltage of the installation point based on the m-order harmonic voltage after the correction, and an output controller to control an output of the active filter based on a first compensation command value.