Abstract: A method for controlling an inverter-based resource having a power converter connected to an electrical grid includes receiving, via a regulator of a controller of the inverter-based resource, a plurality of power signals. The method also includes determining, via the regulator, a power error signal as a function of the plurality of power signals. Further, the method includes receiving, via the regulator, a dynamic multiplier factor from a supervisory controller. Moreover, the method includes applying, via the regulator, the dynamic multiplier factor to one or more gains of the regulator to determine one or more modified gains. In addition, the method includes applying the one or more modified gains to the power error signal to obtain an intermediate power signal. Thus, the method includes generating, via the regulator, one or more control commands for the power converter as a function of the intermediate power signal.

Abstract: A method for controlling an inverter-based resource (IBR) having a power converter and a generator connected to an electrical grid includes determining an available active power of the electrical grid. The method also includes determining an available active power of the IBR based on an effect of a speed and a rating of the generator. Further, the method includes determining a minimum available active power based on the available active power of the electrical grid and the available active power of the IBR. Moreover, the method includes determining an active power limit change for the IBR based on one or more thermal margins of the IBR. In addition, the method includes determining an active power estimation as a function of the minimum available active power and the active power limit change. The method further includes providing the active power estimation to a supervisory controller for controlling the IBR.

Abstract: A method for controlling an inverter-based resource (IBR) having a power converter and a generator connected to an electrical grid includes determining an available active power of the electrical grid. The method also includes determining an available active power of the IBR based on an effect of a speed and a rating of the generator. Further, the method includes determining a minimum available active power based on the available active power of the electrical grid and the available active power of the IBR. Moreover, the method includes determining an active power limit change for the IBR based on one or more thermal margins of the IBR. In addition, the method includes determining an active power estimation as a function of the minimum available active power and the active power limit change. The method further includes providing the active power estimation to a supervisory controller for controlling the IBR.

Abstract: A method for controlling an inverter-based resource having a power converter connected to an electrical grid includes receiving, via a regulator of a controller of the inverter-based resource, a plurality of power signals. The method also includes determining, via the regulator, a power error signal as a function of the plurality of power signals. Further, the method includes receiving, via the regulator, a dynamic multiplier factor from a supervisory controller. Moreover, the method includes applying, via the regulator, the dynamic multiplier factor to one or more gains of the regulator to determine one or more modified gains. In addition, the method includes applying the one or more modified gains to the power error signal to obtain an intermediate power signal. Thus, the method includes generating, via the regulator, one or more control commands for the power converter as a function of the intermediate power signal.

Abstract: A method for operating a multi-level bridge power converter includes providing a plurality of switching devices of the power converter in one of a neutral point clamped topology or an active neutral point clamped topology. The method also includes providing a plurality of deadtimes for the switching devices. Further, the method includes selecting one of the deadtimes for each of the switching devices such that at least two of the switching devices operate according to different deadtimes. Moreover, the method includes operating the switching devices at the selected deadtimes to allow a first group of the switching devices to switch slower than a second group of the switching devices such that the first group of the switching devices satisfy safe operating requirements while the second group of the switching devices switch faster than the first group.

Abstract: A system and method are provided for controlling low-speed operations of a wind turbine electrically coupled to an electrical grid. The wind turbine includes a generator and a power converter. The generator includes a generator rotor and a generator stator. An operating parameter of the generator rotor is indicative of a low-speed operation of the generator. Accordingly, the crossing of a first threshold by the operating parameter is detected. In response, at least a portion of a required reactive power generation is developed via the generator rotor. The portion is then delivered to the electrical grid via the grid side of the power converter.

Abstract: A method includes receiving, via one or more turbine-level controllers, an indication of at least one of a communication loss between the one or more turbine-level controllers and a farm-level controller, a detection of an absence of reactive power regulation by the farm-level controller, or a reactive power command of the farm-level controller being equal to or above a saturation threshold during transitioning between a baseline operational mode and reactive power mode, the reactive power mode being characterized in that only reactive power is generate. Upon receipt of the indication, the method includes adjusting a reactive power response of one or more reactive power regulators of the one or more turbine-level controllers so as to avoid an overshoot reactive power event or an undershoot reactive power event at the point of interconnection.

Abstract: A system and method are provided for operating a power generating asset electrically coupled to a power grid. The power generating asset includes a power converter having a line-side converter operably coupled to the power grid via a converter contactor. Accordingly, a line-side converter of the power converter is decoupled from the power grid and a controller determines the phase angle of the grid voltage. A switching sequence for a plurality switching devices of the line-side converter is then set in order to develop a pre-charge voltage phase angle at a converter-side terminal of the converter contactor which is in phase with the phase angle of the grid voltage. A portion of the charge of the DC link is then discharged through the line-side converter to develop a pre-charge voltage at the converter-side terminal. Once the in-phase, pre-charge voltage is established at the converter-side terminal, the converter contactor is closed to re-couple the line-side converter to the power grid.

Abstract: A system and method are provided for controlling low-speed operations of a wind turbine electrically coupled to an electrical grid. The wind turbine includes a generator and a power converter. The generator includes a generator rotor and a generator stator. An operating parameter of the generator rotor is indicative of a low-speed operation of the generator. Accordingly, the crossing of a first threshold by the operating parameter is detected. In response, at least a portion of a required reactive power generation is developed via the generator rotor. The portion is then delivered to the electrical grid via the grid side of the power converter.

Abstract: A system and method are provided for operating a power generating asset electrically coupled to a power grid. The power generating asset includes a power converter having a line-side converter operably coupled to the power grid via a converter contactor. Accordingly, a line-side converter of the power converter is decoupled from the power grid and a controller determines the phase angle of the grid voltage. A switching sequence for a plurality switching devices of the line-side converter is then set in order to develop a pre-charge voltage phase angle at a converter-side terminal of the converter contactor which is in phase with the phase angle of the grid voltage. A portion of the charge of the DC link is then discharged through the line-side converter to develop a pre-charge voltage at the converter-side terminal. Once the in-phase, pre-charge voltage is established at the converter-side terminal, the converter contactor is closed to re-couple the line-side converter to the power grid.

Abstract: A method for operating a PV system that is integrated into a power system connected to a power grid includes determining a voltage operating point for the PV system based on a maximum power point tracking (MPPT) algorithm. If an available power output of the PV system can be provided to the power grid, the method includes operating the PV system based on the voltage operating point. If the maximum available power output of the PV system cannot be provided to the power grid, the method includes applying a voltage step to the voltage operating point to drive a power output of the PV system towards an external power constraint.

Abstract: A hybrid power system (100) comprising a wind turbine (102) having a wind turbine generator and a power converter, and one or more DC power sources (104). The hybrid power system is configured to prioritize active power output over reactive power capability when the wind turbine is not operating, and is further configured to prioritize reactive power capability over active power output when the wind turbine is operating and wind speed is above a predetermined threshold. Methods for operating a hybrid power system are also provided.

Abstract: A method for operating a power generation system that supplies real and reactive power to a grid includes receiving a reactive power demand made on the power generation system at an operating state of the power generation system and a grid state. Further, the method includes decoupling reactive power control and voltage control between a generator and a reactive power compensation device so as to reduce an oscillatory response of a reactive power output from the reactive power compensation device and the generator. Moreover, the method includes operating, via a device controller, the reactive power compensation device in a reactive power control mode to generate at least a portion of the reactive power demand.

Abstract: A method for operating a power generation system that supplies real and reactive power to a grid includes receiving a reactive power demand made on the power generation system at an operating state of the power generation system and a grid state. Further, the method includes decoupling reactive power control and voltage control between a generator and a reactive power compensation device so as to reduce an oscillatory response of a reactive power output from the reactive power compensation device and the generator. Moreover, the method includes operating, via a device controller, the reactive power compensation device in a reactive power control mode to generate at least a portion of the reactive power demand.

Abstract: A method for operating a PV system that is integrated into a power system connected to a power grid includes determining a voltage operating point for the PV system based on a maximum power point tracking (MPPT) algorithm. If an available power output of the PV system can be provided to the power grid, the method includes operating the PV system based on the voltage operating point. If the maximum available power output of the PV system cannot be provided to the power grid, the method includes applying a voltage step to the voltage operating point to drive a power output of the PV system towards an external power constraint.

Abstract: A method for controlling a dual-fed induction generator (DFIG) connected to a power grid in response to a high-voltage grid event includes receiving, via a controller, a frequency signal of the power grid. The method also includes filtering the frequency signal via a filtering assembly so as to determine whether certain types of grid conditions are present in the power grid. The filtering assembly includes a first filter connected in parallel with a second filter. The first filter has a bandwidth that is greater than the second filter. Further, the method also includes comparing output signals of the first and second filters of the filtering assembly to one or more frequency thresholds. Moreover, the method includes controlling the DFIG based on the comparison.

Abstract: A method for controlling a dual-fed induction generator (DFIG) connected to a power grid in response to a high-voltage grid event includes receiving, via a controller, a frequency signal of the power grid. The method also includes filtering the frequency signal via a filtering assembly so as to determine whether certain types of grid conditions are present in the power grid. The filtering assembly includes a first filter connected in parallel with a second filter. The first filter has a bandwidth that is greater than the second filter. Further, the method also includes comparing output signals of the first and second filters of the filtering assembly to one or more frequency thresholds. Moreover, the method includes controlling the DFIG based on the comparison.

Abstract: A method for operating a renewable energy power system connected to a power grid includes operating the renewable energy power system at one or more first operational settings. The method also includes monitoring the renewable energy power system for electrical oscillations caused by a grid or system disturbance. In response to detecting the electrical oscillations being above a predetermined threshold indicative of the one or more first operational settings no longer being suitable for grid conditions, the method includes changing the one or more first operational settings to one or more different, second operational settings so as to reduce the electrical oscillations in the renewable energy power system.

Abstract: A system comprising: a renewable power source (1) with a renewable power generator and a controller (40) for controlling the renewable power source, a power converter (30) electrically coupled with the renewable power generator and configured to connect the renewable power generator with an electrical grid, and the power converter comprising a DC link (31), and an energy storage device (50) configured to be electrically coupled with the DC link. The controller is configured to receive a signal from the energy storage device (50) and transmit this signal from the energy storage device to the power converter (30). Further disclosed are methods for connecting a DC link (31) of a power converter (30) with an energy storage device (50) and methods for transmitting information between a power converter (30) coupled to a generator of a turbine and an energy storage device (50).

Abstract: System and methods for optimizing operation of a wind turbine are disclosed. In one aspect, the method also includes determining, via a converter controller of a power converter, a tap position of a tap changer configured between the power grid and a primary winding of a transformer. Another step includes calculating, via the converter controller, a primary voltage of the primary winding as a function of the tap position. The method also includes implementing, via the converter controller, a control action if the primary voltage or a measured secondary voltage of a secondary winding of the transformer is outside of a predetermined voltage range.