In order to output sufficient reactive power for voltage stabilization of a utility grid, and calculate an appropriate consideration according to an amount of the output reactive power, is provided a control device for controlling a distributed power source connected to the utility grid, comprising: a range setting unit where an allowable range of reactive and active powers output at normal times is set; an output control unit for controlling the reactive and active powers supplied from the distributed power source to the utility grid within the allowable range set in the range setting unit; and a reception unit for receiving, from a command device in the utility grid, an excess output command indicating that the reactive power exceeding the allowable range should be output, wherein the output control unit is for outputting the reactive power out of the allowable range when the reception unit receives the excess output command.

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.

Systems and methods for managing loads on a power grid are provided. In some embodiments, the load control system includes one or more power sources connected to a power grid. A method includes determining, by a first genset connected to a power grid, a power average at a first rate, and generating, by the first genset, a filtered power average. The filtered average includes the power average at a second rate. The filtered power average is used in a second algorithm to balance the load share of power sources on the power grid.

Systems and methods for managing loads on a power grid are provided. In some embodiments, the load control system includes one or more power sources connected to a power grid. A method includes determining, by a first genset connected to a power grid, a power average at a first rate, and generating, by the first genset, a filtered power average. The filtered average includes the power average at a second rate. The filtered power average is used in a second algorithm to balance the load share of power sources on the power grid.

Various embodiments disclosed herein generally relate to methods and systems for real-time, or near real-time, balancing of an electrical distribution grid. According to at least one embodiment, there is provided one or more local balancing systems, each comprising: an energy storage unit (ESU) operable to store direct current (DC) power; a power converter comprising a DC side and an AC side, the power converter being operable to convert between single-phase (AC) power and DC power, wherein the DC side is electrically coupled to the ESU and the AC side is electrically couplable to at least one secondary distribution block in a secondary distribution grid; and a local controller coupled to the power converter and operable to control the power converter to convert between DC power and AC power.

Various embodiments disclosed herein generally relate to methods and systems for real-time, or near real-time, balancing of an electrical distribution grid. According to at least one embodiment, there is provided one or more local balancing systems, each comprising: an energy storage unit (ESU) operable to store direct current (DC) power; a power converter comprising a DC side and an AC side, the power converter being operable to convert between single-phase (AC) power and DC power, wherein the DC side is electrically coupled to the ESU and the AC side is electrically couplable to at least one secondary distribution block in a secondary distribution grid; and a local controller coupled to the power converter and operable to control the power converter to convert between DC power and AC power.

A method tests the configuration of an aggregated DERs system using distributed asset managers in a decentralized hardware-in-the-loop (“HIL”) scheme. The managers contain the model of the asset they are meant to control. The method programs an asset manager with a model of a DERs asset. A plurality of asset managers are connected to a central controller. The plurality of asset managers are also connected to a simplified hardware-in-the-loop platform. The simplified HIL platform is configured to solve a network model, a load model, a non-controllable asset model, and a grid model. The method tests the DERs system control structure by using: (a) the simplified HIL platform to solve the network model, the load model, the non-controllable asset model, and the grid model, and (b) the asset manager to solve the model of the DERs asset, without any simulation between the central controller and the distributed asset managers.

A method tests the configuration of an aggregated DERs system using distributed asset managers in a decentralized hardware-in-the-loop (“HIL”) scheme. The managers contain the model of the asset they are meant to control. The method programs an asset manager with a model of a DERs asset. A plurality of asset managers are connected to a central controller. The plurality of asset managers are also connected to a simplified hardware-in-the-loop platform. The simplified HIL platform is configured to solve a network model, a load model, a non-controllable asset model, and a grid model. The method tests the DERs system control structure by using: (a) the simplified HIL platform to solve the network model, the load model, the non-controllable asset model, and the grid model, and (b) the asset manager to solve the model of the DERs asset, without any simulation between the central controller and the distributed asset managers.

Methods and apparatuses for controlling reactive power of a wind turbine, and a wind farm are provided. An exemplary method includes: obtaining operation data of single wind turbines in a wind turbine group at the current time point; determining the total maximum capacitive reactive capacity and total minimum inductive reactive capacity, satisfying a safety constraint condition at the next time point, of the wind turbine group; calculating a deviation value of a wind turbine group reactive instruction at the current time point; and updating the wind turbine group reactive instruction on the basis of the acquired, determined, and calculated data so as to perform reactive power control.