Abstract: A method for validating an electric power plant capability as an electric service provider is provided. The method includes receiving a plurality of input data records from the plurality of renewable energy devices, respectively, the input data records respectively defining a plurality of device capabilities associated with at least one electrical service which can be provided by the renewable energy devices to the electric distribution grid; estimating internal power losses of the electric power plant; using the input data records and the internal power losses for calculating an output data record defining an overall plant capability for the service; communicating the output data record to an operator of the electric distribution grid; and receiving a validation signal from the operator of the electric distribution grid.

Abstract: A wind park control system for controlling wind turbines of a wind park during a plant controller handover is provided. A plurality of plant controllers compute control values on the basis of system input data, which plant controllers are realized to operate in parallel. One of the plant controllers operates as an active plant controller for computing control values for controlling the wind turbines. One further plant controller operates as a standby plant controller. An output means continually issues control values to the wind turbines of the wind park. A handover arrangement for handing over control from the hitherto active plant controller to an operative standby plant controller is provided such that that standby plant controller then assumes the function of active plant controller. Further, a wind park, a method of controlling a wind park, and a method of performing a plant controller handover in a wind park are provided.

Abstract: A method is provided for controlling a wind power plant, in particular in case of a frequency drop in a utility grid to which the wind turbines are connected, the method including: Combining demand response, inertial response and spinning reserve for given wind speeds in order for wind power plants to deliver fast aggregate under frequency response for a wide wind speed range with minimal recovery time and minimal production loss at each wind speed. In case of the frequency drop the utility grid is additional stabilized by active power, which is provided from a static VAR-compensator and which is fed into the grid. The static VAR-compensator is connected with the wind turbine via a transmission system. The static VAR-compensator is based on using super-capacitors thus it can provide an amount of active power for grid support in case of the frequency drop.

Abstract: A method is provided for controlling a power network that includes a plurality of power generation facilities connected to an electricity grid and a plurality of power storage facilities connected to the power generation facilities. The method includes monitoring a production capacity of the power generation facilities, monitoring a storage capacity of the power storage facilities and determining an optimal facility control plan on the basis of the storage capacity and the production capacity. The method further includes operating the power network, according to the facility control plan, to feed power from the power generation facilities into the electricity grid and/or to transfer power from the power generation facilities to the power storage facilities and/or to consume power from the power storage facilities.

Abstract: A method for compensating at least partially a frequency deviation in a grid is provided in which a grid frequency is determined and the grid frequency is applied to a grid frequency criterion. If the grid frequency meets the grid frequency criterion, a determination is made as to a set of wind turbines from a wind turbine power plant fleet based on the grid frequency criterion, and a command for a transient frequency response is transmitted to the set of wind turbines.

Abstract: A wind turbine device having in one embodiment a diesel generator to initialize a black start in case of a blackout of an electricity network is disclosed. For performing the black start, the diesel generator provides a predetermined voltage to a power output of the wind turbine device in order to imitate the electricity network in its running state. A wind park is also disclosed, the wind park having in one embodiment at least two wind turbine devices. In one embodiment a wind park controller provides the same reference value for the phase angle ? for the at least two turbines.

Abstract: A method of controlling a wind power plant, the wind power plant having a plurality of wind turbines and being connected to a power grid is provided. The method includes (a) detecting a grid frequency instability, (b) selecting a subset of wind turbines, (c) modifying a power reference for each wind turbine in the selected subset of wind turbines to respond to the grid frequency instability, and (d) applying the modified power references to the corresponding wind turbines in the selected subset of wind turbines. A wind power plant controller, a wind power plant, a computer program, and a computer program product are also provided.

Abstract: A method for determining electrical characteristics at a point of regulation to which plural energy providing/production units are connected via a common node is provided. The electrical characteristics at an output terminal of each of the plural energy providing/production units are measured in order to obtain plural measured electrical characteristics. Circuit configuration information about a configuration of a circuitry connected between the plural energy providing/production units and the point of regulation is obtained. Electrical characteristics at the point of regulation are calculated based on the plural measured electrical characteristics and the circuit configuration information.

Abstract: It is described a method for coupling plural wind turbines to a utility grid after the wind turbines have been disconnected from the utility grid, the method comprising: closing a main breaker arranged between the utility grid and a main transformer resulting in reactive current flowing from the utility grid to the main transformer; closing a first feeder switch arranged between the main transformer and a first group of wind turbines of the plural wind turbines; selecting a first reference voltage; operating first converters of the first group of wind turbines in a voltage control mode according to the first reference voltage; and closing a second feeder switch.

Abstract: A method to control the operation of a wind turbine is provided. According to the method a sound of a bat in the area of the wind turbine is detected. According to the detected sound of the bat in the area of the wind turbine a parameter for the operation of the wind turbine is set.

Abstract: A method of operating a wind turbine of a wind park is provided. In a first step a status of a communication connection to a wind park controller is checked. When the status of the communication connection is positive, the wind turbine will be operated in accordance with at least one reference set point received from the wind park controller. When the status of the communication connection is negative, a substitute reference set point will be determined as a function of a present power output of the wind turbine and the wind turbine will be operated in accordance with the substitute reference set point.

Abstract: A method for validating an electric power plant capability as an electric service provider is provided. The method includes receiving a plurality of input data records from the plurality of renewable energy devices, respectively, the input data records respectively defining a plurality of device capabilities associated with at least one electrical service which can be provided by the renewable energy devices to the electric distribution grid; estimating internal power losses of the electric power plant; using the input data records and the internal power losses for calculating an output data record defining an overall plant capability for the service; communicating the output data record to an operator of the electric distribution grid; and receiving a validation signal from the operator of the electric distribution grid.

Abstract: Described is a controller, wherein the controller is adapted: to control a transformation ratio of a park transformer of a wind turbine park including wind turbines connected to a first node. The park transformer is connected between a first node and a second node which is connected to a utility grid to which electric energy produced by the wind turbines is to be delivered. Further a wind park and a control method are described.

Abstract: A method of controlling a power plant connected at a point of connection to an electricity grid is provided. The power plant includes a power production facility connected to a power storage facility. The method includes determining a reactive power grid demand and/or voltage grid demand of the electricity grid, obtaining operating data for the power plant facilities, computing reactive power and/or voltage references for the power plant facilities on the basis of the grid demands and the operating data, and operating the power plant facilities on the basis of the references such that a net reactive power and/or a net voltage at the point of connection fulfills a grid demand. A plant controller for controlling a power plant is also provided. A power plant including power production facilities connected to power storage facilities, and the plant controller using the method is also provided.

Abstract: Disclosed is a test system for determining a frequency response of a virtual power plant connected to a utility grid and including a plurality of distinct power plants. The test system includes a test sequence module for providing a frequency test sequence. The frequency test sequence includes a set of frequency test values; and an injection unit for injecting values of the frequency test sequence simultaneously to nodes of the virtual power plant. A node of the virtual power plant includes any of: a power production unit of a power plant, a power storage unit of a power plant, a plant controller of a power plant. Further described are a virtual power plant and a method of testing a frequency response of a virtual power plant.

Abstract: A method is provided for operating a controller controlling an energy production plant including plural wind turbines each having an electrical output terminal connected to a common node. The method involves determining that a failure relating to the energy production plant has been overcome; receiving a first signal indicative of an actual value of an electrical quantity at the common node; receiving a second signal relating to a desired value of the electrical quantity at the common node; generating plural reference signals based on an intermediate value between the actual value and the desired value; and supplying the reference signals to the wind turbines, the reference signals controlling the wind turbines with respect to their electrical output at the output terminal such that the intermediate value of the electrical quantity at the common node is achieved.

Abstract: It is described a method for coupling plural wind turbines to a utility grid after the wind turbines have been disconnected from the utility grid, the method comprising: closing a main breaker arranged between the utility grid and a main transformer resulting in reactive current flowing from the utility grid to the main transformer; closing a first feeder switch arranged between the main transformer and a first group of wind turbines of the plural wind turbines; selecting a first reference voltage; operating first converters of the first group of wind turbines in a voltage control mode according to the first reference voltage; and closing a second feeder switch.

Abstract: A method of controlling a wind power plant, the wind power plant having a plurality of wind turbines and being connected to a power grid is provided. The method includes (a) detecting a grid frequency instability, (b) selecting a subset of wind turbines, (c) modifying a power reference for each wind turbine in the selected subset of wind turbines to respond to the grid frequency instability, and (d) applying the modified power references to the corresponding wind turbines in the selected subset of wind turbines. A wind power plant controller, a wind power plant, a computer program, and a computer program product are also provided.

Abstract: An electric power control system is provided. The power control system includes a first node to which a plurality of power production entities are connectable for combining their power output signals as a first power signal, a transformer adapted to transformer the first power signal at the first node to a second power signal at a second node connectable to a load, the second power signal having a higher voltage than the first power signal, at least one capacitor connectable to the first node and/or to the second node, a control unit adapted to control the connection of the at least one capacitor to the first node and/or to the second node such that a power loss caused by transmission loss of the power output signals from the power production entities to the load is minimized.

Abstract: A method for compensating at least partially a frequency deviation in a grid is provided in which a grid frequency is determined and the grid frequency is applied to a grid frequency criterion. If the grid frequency meets the grid frequency criterion, a determination is made as to a set of wind turbines from a wind turbine power plant fleet based on the grid frequency criterion, and a command for a transient frequency response is transmitted to the set of wind turbines.