Abstract: A system and method are provided for controlling a wind farm during low wind speeds. Accordingly, the farm controller designates at least one of the plurality of wind turbines of the wind farm as a designated turbine. The designated turbine is operating in a full auxiliary mode when the speed of the wind acting on the wind farm is below a wind speed threshold. The remaining wind turbines are operated in a reduced auxiliary mode. The reduced auxiliary mode includes the disabling of at least one of pitching and yawing of the remaining wind turbines. When a power output for the designated wind turbine exceeds a power threshold, the farm controller directs at least one group of the remaining wind turbines to transition from the reduced auxiliary mode to the full auxiliary mode. During certain grid conditions, the transition between auxiliary modes may be delayed.

Abstract: The system and method described herein provide grid-forming control of a power generating asset having a generator, such as a double-fed generator, connected to a power grid. Accordingly, a stator-frequency error is determined for the generator. The components of the stator frequency error are identified as a damping component corresponding to a tower damping frequency and a stator component. Based on the stator component, a power output requirement for the generator is determined. This power output requirement is combined with the damping power command to develop a consolidated power requirement for the generator. Based on the consolidated power requirement, at least one control command for the generator is determined and an operating state of the generator is altered.

Abstract: A method for controlling an energy generation and storage system using a multi-layer architecture is provided. The method includes determining, by one or more control devices, a power or energy generation for the energy generation and storage system at a first layer of the multi-layer architecture. The method includes determining, by the one or more control devices, a power or energy set point for the system at a second layer of the multi-layer architecture. The method includes controlling, by the one or more control devices, the energy generation and storage system based, at least in part, on the power or energy setpoint.

Abstract: A method of operating a power generation system (100) employing a generator (110) and a solar power source (120) is provided. The method includes the steps of determining (310) if a wind speed is less than a cut-in speed, calculating (315) a reactive power demand for an electrical grid (102), calculating (320) a reactive power capability of a line side converter (140), determining (325) if the reactive power demand is greater than the reactive power capability, and calculating (330) a reactive power capability of the line side converter (140) and a rotor side converter (130). The method also includes the steps of determining (335) if the reactive power demand is greater than the reactive power capability of the line side converter (140) and the rotor side converter (130), and reducing solar power generation or reconfiguring the line side converter (140) and/or the rotor side converter (130) to meet reactive power demand.

Abstract: A method for estimating grid strength of a power grid connected to a renewable energy farm having a plurality of renewable energy power systems includes measuring, at least, a voltage, an active power, and a reactive power at a point of interconnection of the renewable energy farm to the power grid. The method also includes determining a sensitivity of the voltage to at least one of the active power or the reactive power at the point of interconnection. Further, the method includes determining the grid strength of the power grid as a function of the sensitivity of the voltage to at least one of the active power or the reactive power at the point of interconnection. In addition, the method includes dynamically determining at least one of an active power command or a reactive power command for the renewable energy farm at the point of interconnection based on the grid strength.

Abstract: A method for estimating grid strength of a power grid connected to a renewable energy farm having a plurality of renewable energy power systems includes measuring, at least, a voltage, an active power, and a reactive power at a point of interconnection of the renewable energy farm to the power grid. The method also includes determining a sensitivity of the voltage to at least one of the active power or the reactive power at the point of interconnection. Further, the method includes determining the grid strength of the power grid as a function of the sensitivity of the voltage to at least one of the active power or the reactive power at the point of interconnection. In addition, the method includes dynamically determining at least one of an active power command or a reactive power command for the renewable energy farm at the point of interconnection based on the grid strength.

Abstract: A method for operating a wind farm connected to a power grid that demands a reactive power requirement that varies with active power includes monitoring a wind speed at each of the plurality of wind turbines in the wind farm. When the wind speed is within a cut-in wind speed range, the method includes determining a reactive power margin of the wind farm based on the reactive power requirement at an active power output corresponding to the wind speed and a reactive power availability of each of the plurality of wind turbines at the wind speed. The method also includes determining a lowest possible cut-in rotor speed for each of the plurality of wind turbines that satisfies the reactive power margin. Further, the method includes commanding each of the plurality of wind turbines to cut-in and begin to produce power at the lowest possible cut-in rotor speed that satisfies the reactive power margin.

Abstract: A method for operating at least one energy storage device of a renewable energy facility connected to a power grid in multiple operational modes includes providing an operational threshold for the renewable energy facility. Further, the method includes comparing an operational parameter of the renewable energy facility with respect to the operational threshold. The method also includes controlling the renewable energy facility based on the comparison. As such, when the operational parameter is below the operational threshold, the controller communicates to the energy storage device(s) to increase its state of charge (SOC) in anticipation of the renewable energy facility transitioning from producing power to consuming power.

Abstract: A method for controlling an energy generation and storage system using a multi-layer architecture is provided. The method includes determining, by one or more control devices, a power or energy generation for the energy generation and storage system at a first layer of the multi-layer architecture. The method includes determining, by the one or more control devices, a power or energy set point for the system at a second layer of the multi-layer architecture. The method includes controlling, by the one or more control devices, the energy generation and storage system based, at least in part, on the power or energy setpoint.

Abstract: A control method for dynamically controlling active and reactive power capability of a wind farm includes obtaining one or more real-time operating parameters of each of the wind turbines. The method also includes obtaining one or more system limits of each of the wind turbines. Further, the method includes measuring at least one real-time wind condition at each of the wind turbines. Moreover, the method includes continuously calculating an overall maximum active power capability and an overall maximum reactive power capability for each of the wind turbines as a function of the real-time operating parameters, the system limits, and/or the real-time wind condition. Further, the method includes generating a generator capability curve for each of the wind turbines using the overall maximum active and reactive power capabilities and communicating the generator capability curves to a farm-level controller of the wind farm that can use the curves to maximize the instantaneous power output of the wind farm.

Abstract: A method for operating at least one energy storage device of a renewable energy facility connected to a power grid in multiple operational modes includes providing an operational threshold for the renewable energy facility. Further, the method includes comparing an operational parameter of the renewable energy facility with respect to the operational threshold. The method also includes controlling the renewable energy facility based on the comparison. As such, when the operational parameter is below the operational threshold, the controller communicates to the energy storage device(s) to increase its state of charge (SOC) in anticipation of the renewable energy facility transitioning from producing power to consuming power.

Abstract: A control method for dynamically controlling active and reactive power capability of a wind farm includes obtaining one or more real-time operating parameters of each of the wind turbines. The method also includes obtaining one or more system limits of each of the wind turbines. Further, the method includes measuring at least one real-time wind condition at each of the wind turbines. Moreover, the method includes continuously calculating an overall maximum active power capability and an overall maximum reactive power capability for each of the wind turbines as a function of the real-time operating parameters, the system limits, and/or the real-time wind condition. Further, the method includes generating a generator capability curve for each of the wind turbines using the overall maximum active and reactive power capabilities and communicating the generator capability curves to a farm-level controller of the wind farm that can use the curves to maximize the instantaneous power output of the wind farm.

Abstract: Systems and methods for operating a power system having a doubly fed induction generator are provided. In example implementations, a power system can include a power converter. The power converter can include a line-side converter, a DC link, and a rotor-side converter. The rotor-side converter is configured to convert a DC power on the DC link to an AC signal for a rotor bus. The system can include a control system having one or more control devices.