A power supporting arrangement includes a DC network having a first DC line with a first DC potential, a second DC line with a second DC potential, and an energy storage system that includes a first energy storage unit connected in a branch between the first and the second DC lines. A first group of phase arms is connected in a wye-configuration between the power grid and the first DC line and a second group of phase arms connected in a wye-configuration between the power grid and the second DC line. The first and second groups of phase arms are controllable as a voltage source converter. A third group of phase arms is connected to the power grid in a wye-configuration. The third group of phase arms have a neutral point and being controllable to support the power grid with reactive power.

A power supporting arrangement includes a DC network having a first DC line with a first DC potential, a second DC line with a second DC potential, and an energy storage system that includes a first energy storage unit connected in a branch between the first and the second DC lines. A first group of phase arms is connected in a wye-configuration between the power grid and the first DC line and a second group of phase arms connected in a wye-configuration between the power grid and the second DC line. The first and second groups of phase arms are controllable as a voltage source converter. A third group of phase arms is connected to the power grid in a wye-configuration. The third group of phase arms have a neutral point and being controllable to support the power grid with reactive power.

A method for monitoring a three-phase network that is operated in a compensated manner for a tuning change of the arc suppression coil. Reference network parameters and a reference network frequency are determined for a tuned state, and a current network frequency is determined for a current state. A reference characteristic variable, which is proportional to a displacement voltage, is determined for the current network frequency using the reference network parameters, and a current characteristic variable, which is proportional to a displacement voltage, is determined at the current network frequency. A differential variable is determined from the reference characteristic variable and the current characteristic variable, from which, with a predetermined threshold value being exceeded, a tuning change is identified and changed network parameters are determined.

The present techniques generally concern methods and systems for monitoring and managing reactive power from horticultural lighting sources in an electrical grid. The techniques provided herein include determining or predicting distortive effects produced by the horticultural lighting sources, evaluating a power factor of the horticultural light sources, and based on a target power factor, adjusting the power factor of the horticultural light sources. The techniques described herein allow for an optimization of the power factor of the horticultural lighting sources in order to reduce, mitigate or eliminate the negative effects generally associated with the operation of horticultural light sources on the electrical grid.

A method and associated apparatus for feeding electric power from a photovoltaic system via a grid connection point into an AC grid having a low short-circuit power is disclosed. The method includes connecting a DC voltage side of at least one first inverter of the photovoltaic system to a photovoltaic generator and an AC voltage side of the at least one first inverter to the grid connection point, wherein the at least one first inverter is operated as a current source, and connecting an AC voltage side of a second inverter of the photovoltaic system to the grid connection point, wherein the second inverter is operated as a voltage source based on measurement values of an AC voltage measured in the region of the photovoltaic system and a predefined characteristic curve. For a first total short-circuit power of all first inverters operated as a current source, and a second total short-circuit power of the AC grid and of the second inverter operated as a voltage source, a ratio of the second total short-circuit power to the first total short-circuit power is greater than or equal to 2.

A method and associated apparatus for feeding electric power from a photovoltaic system via a grid connection point into an AC grid having a low short-circuit power is disclosed. The method includes connecting a DC voltage side of at least one first inverter of the photovoltaic system to a photovoltaic generator and an AC voltage side of the at least one first inverter to the grid connection point, wherein the at least one first inverter is operated as a current source, and connecting an AC voltage side of a second inverter of the photovoltaic system to the grid connection point, wherein the second inverter is operated as a voltage source based on measurement values of an AC voltage measured in the region of the photovoltaic system and a predefined characteristic curve. For a first total short-circuit power of all first inverters operated as a current source, and a second total short-circuit power of the AC grid and of the second inverter operated as a voltage source, a ratio of the second total short-circuit power to the first total short-circuit power is greater than or equal to 2.

A method, apparatus, system and computer program is provided for controlling an electric power system, including implementation of a voltage control and conservation (VCC) system used to optimally control the independent voltage and capacitor banks using a linear optimization methodology to minimize the losses in the EEDCS and the EUS. An energy validation process system (EVP) is provided which is used to document the savings of the VCC and an EPP is used to optimize improvements to the EEDCS for continuously improving the energy losses in the EEDS. The EVP system measures the improvement in the EEDS a result of operating the VCC system in the “ON” state determining the level of energy conservation achieved by the VCC system. In addition the VCC system monitors pattern recognition events and compares them to the report-by-exception data to detect HVL events. If one is detected the VCC optimizes the capacity of the EEDS to respond to the HVL events by centering the piecewise linear solution maximizing the ability of the EDDS to absorb the HVL event.

Systems and methods for supplying power (both active and reactive) at a medium voltage from a DCSTATCOM to an IT load without using a transformer are disclosed. The DCSTATCOM includes an energy storage device, a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

A system for managing power delivery and power flow in a distribution grid having grid forming capability is disclosed. The system includes a connect-disconnect switches operable to connect a power transmission grid to and disconnect the power transmission grid from the distribution grid. The distribution grid includes renewable energy generators and a number of loads. The system further includes a full bridge shunt inverter system connected to the distribution grid. The full bridge shunt inverter system includes a four-quadrant DC-to-AC inverter and at least a battery for power storage and operable as a power source for grid formation. The system further includes a pair of active filters connected in series on the distribution grid. The full bridge shunt inverter system is connected to the distribution grid at a node between the active filters to enable impedance adjustment for managing and controlling the power flow in the distribution grid.

Provided is a transformer arrangement wherein active and/or reactive power can be injected in an alternating current link using a current regulator and a voltage regulator portion, wherein at least one winding with which the current regulator is connected in parallel is at least one tertiary winding, and wherein the current regulator includes a number of current regulator sections, each connected to a corresponding voltage regular section of a voltage regulator portion via a corresponding dc link.