Abstract: The invention relates to a method for controlling power generation of a VSM wind turbine. The wind turbine comprises a machine side converter, a line side converter, a DC link, and an electric storage device electrically connected to the DC link. The method comprises determining a first power control signal to the machine side converter, determining a second power control signal for controlling a desired output power of the line side converter based on a storage device voltage error, and a power production reference, and determining a charging current reference for controlling charging and discharging of the electric storage device based on a DC-link voltage error.

Abstract: Controlling a current injected to a power grid from a renewable power plant, in response to a voltage event in the power grid. At least a current at a point of common coupling between the renewable power plant and the power grid is determined and provided to a power plant controller (PPC). The PPC derives individual current setpoint corrections for at least some wind turbines, based on the determined current, and dispatches each derived current setpoint correction to wind turbine controllers of the corresponding wind turbines. The wind turbine controllers control a current output of the respective wind turbines, based on measurements of current and/or voltage at a point of connection between the wind turbine and an internal grid of the renewable power plant, and by taking into account the dispatched current setpoint correction.

Abstract: A method is provided for controlling power oscillations at a point of common coupling in a wind park. Individual power reference offsets defining an adjustment to a wind turbine power reference signal for counteracting mechanical oscillations in the respective wind turbines are received from respective wind turbine controllers. Based on an aggregated power reference offset, a total power oscillation compensation signal is determined. Individual power oscillation compensation signals for adjusting the wind turbine power reference signal of respective wind turbines are determined based on the individual power reference offsets and the total power oscillation compensation signal. These individual power oscillation compensation signals are then sent to the respective wind turbines.

Abstract: A method for detecting power oscillation in an electric power grid, wherein the method comprises: integrating a filtered signal on a first interval, the filtered signal being associated with the electric power grid; based on the integration of the filtered signal on the first interval, determining a positive half-period area of the filtered signal and a negative half-period area of the filtered signal, one of the positive half-period area and negative half-period area being immediately subsequent to the other one; and determining that a power oscillation in the electric power grid is detected if the following two conditions are met: a sum of the positive half-period area of the filtered signal and the negative half-period area of the filtered signal is below a first threshold; and the absolute value of one of the positive half-period area and negative half-period area is above a second threshold.

Abstract: Aspects of the present invention relate to a method of voltage control for at least one wind turbine generator configured to absorb and supply reactive power on demand, the method comprises: receiving a dispatch signal from a power plant controller indicating a reactive power set point; determining a terminal voltage level of the at least one wind turbine generator; generating a reactive power correction value based on a deviation of the terminal voltage level from a voltage set point; adjusting the reactive power set point by the reactive power correction value; and controlling the at least one wind turbine generator according to the adjusted reactive power set point.

Abstract: Aspects of the present invention relate to a method for reducing high torque levels and/or high rates of change of torque in a wind turbine generator that comprises a machine-side converter and a line-side converter connected by a DC link, and, wherein the line-side converter is operated according to a virtual synchronous machine control scheme. The method comprises: determining a generator torque; determining a torque surplus indicating the amount that the generator torque exceeds a torque limit; determining an active power surplus corresponding to the torque surplus; controlling the line-side converter according to the virtual synchronous machine control scheme using an input parameter configured to reduce the active power output of the line side converter by the active power surplus.

Abstract: A method for detecting power oscillation in an electric power grid, wherein the method comprises: integrating a filtered signal on a first interval, the filtered signal being associated with the electric power grid; based on the integration of the filtered signal on the first interval, determining a positive half-period area of the filtered signal and a negative half-period area of the filtered signal, one of the positive half-period area and negative half-period area being immediately subsequent to the other one; and determining that a power oscillation in the electric power grid is detected if the following two conditions are met: a sum of the positive half-period area of the filtered signal and the negative half-period area of the filtered signal is below a first threshold; and the absolute value of one of the positive half-period area and negative half-period area is above a second threshold.

Abstract: The present invention relates to a method for operating a power plant comprising a plurality of power producing units, the power plant being operatively connected to an associated power grid having a nominal grid frequency, the method comprising the steps of determining grid frequency variations of the associated power grid, and providing, in response to the determined grid frequency variations, an active power set-point to each of the plurality of power producing units, said active power set-point causing each of the plurality of power producing units to produce active power in response to said active power set-point, said produced active power comprising, in a frequency domain, one or more active power frequency components being different from one or more undesired frequency modes. The present invention also relates to a power plant controller for performing the method.

Abstract: Aspects of the present invention relate to a method of voltage control for at least one wind turbine generator configured to absorb and supply reactive power on demand, the method comprises: receiving a dispatch signal from a power plant controller indicating a reactive power set point; determining a terminal voltage level of the at least one wind turbine generator; generating a reactive power correction value based on a deviation of the terminal voltage level from a voltage set point; adjusting the reactive power set point by the reactive power correction value; and controlling the at least one wind turbine generator according to the adjusted reactive power set point.

Abstract: The present invention relates to a power system having a plurality wind turbine generators and a power plant controller arranged to communicate with the plurality of wind turbines generators, where each of the plurality of wind turbine generator being related to a wind turbine controller, the wind turbine controller being arranged to control an active power output in its related wind turbine generator according to an active power set point received from the wind power plant controller; a first subset of wind turbine generators operating at an active power output unrestricted of the active power set point; and a second subset of wind turbine generators operating according to an active power set point; and wherein the wind power plant controller communicates the active power set point, in accordance with the active power output of the first subset of the plurality of wind turbines generators, so as to reduce active power fluctuation of the aggregated active power output of the first and second subset of the plu

Abstract: The present invention relates to a power system having a plurality wind turbine generators and a power plant controller arranged to communicate with the plurality of wind turbines generators, where each of the plurality of wind turbine generator being related to a wind turbine controller, the wind turbine controller being arranged to control an active power output in its related wind turbine generator according to an active power set point received from the wind power plant controller; a first subset of wind turbine generators operating at an active power output unrestricted of the active power set point; and a second subset of wind turbine generators operating according to an active power set point; and wherein the wind power plant controller communicates the active power set point, in accordance with the active power output of the first subset of the plurality of wind turbines generators, so as to reduce active power fluctuation of the aggregated active power output of the first and second subset of the plu

Abstract: The present invention relates to a method for operating a power plant comprising a plurality of power producing units, the power plant being operatively connected to an associated power grid having a nominal grid frequency, the method comprising the steps of determining grid frequency variations of the associated power grid, and providing, in response to the determined grid frequency variations, an active power set-point to each of the plurality of power producing units, said active power set-point causing each of the plurality of power producing units to produce active power in response to said active power set-point, said produced active power comprising, in a frequency domain, one or more active power frequency components being different from one or more undesired frequency modes. The present invention also relates to a power plant controller for performing the method.

Abstract: A method for controlling a wind turbine is disclosed. During full load operation, a power reference value, Pref, representing a power level to be supplied to the power grid by the wind turbine, is received, and the wind turbine is controlled in order to produce an output power which is at or near the power reference value, Pref, while maintaining a constant torque on the generator. In the case that the produced output power of the wind turbine exceeds the power reference value, Pref, excess produced energy is stored in the energy storage system, and in the case that the produced output power of the wind turbine is below the power reference value, Pref, stored energy is retrieved from the energy storage system. A power level being equal to the power reference value, Pref, is supplied to the power grid.

Abstract: A method for controlling a wind turbine is disclosed. During full load operation, a power reference value, Pref, representing a power level to be supplied to the power grid by the wind turbine, is received, and the wind turbine is controlled in order to produce an output power which is at or near the power reference value, Pref, while maintaining a constant torque on the generator. In the case that the produced output power of the wind turbine exceeds the power reference value, Pref, excess produced energy is stored in the energy storage system, and in the case that the produced output power of the wind turbine is below the power reference value, Pref, stored energy is retrieved from the energy storage system. A power level being equal to the power reference value, Pref, is supplied to the power grid.

Abstract: Systems, methods, and computer program products for providing an inertial response by a wind power system to power fluctuations in an electrical grid. The system includes a synthetic inertial response generator configured to generate a power offset in response to fluctuations in grid voltage. The power offset signal is generated by determining a quadrature component the grid voltage using an internal reference voltage having an angular frequency and phase angle that is synchronized to the electrical grid by a control loop. The quadrature component is used to determine a synchronous power level. A control loop error signal is produced by the difference between the synchronous power level and the wind turbine system power output. Changes in the grid frequency produce an error signal that is added to the power set point of wind turbine system output controllers to provide a power system inertial power output response.

Abstract: The present invention relates to a power system having a plurality wind turbine generators and a power plant controller arranged to communicate with the plurality of wind turbines generators, where each of the plurality of wind turbine generator being related to a wind turbine controller, the wind turbine controller being arranged to control an active power output in its related wind turbine generator according to an active power set point received from the wind power plant controller; a first subset of wind turbine generators operating at an active power output unrestricted of the active power set point; and a second subset of wind turbine generators operating according to an active power set point; and wherein the wind power plant controller communicates the active power set point, in accordance with the active power output of the first subset of the plurality of wind turbines generators, so as to reduce active power fluctuation of the aggregated active power output of the first and second subset of the plu

Abstract: Systems, methods, and computer program products for providing an inertial response by a wind power system to power fluctuations in an electrical grid. The system includes a synthetic inertial response generator configured to generate a power offset in response to fluctuations in grid voltage. The power offset signal is generated by determining a quadrature component the grid voltage using an internal reference voltage having an angular frequency and phase angle that is synchronized to the electrical grid by a control loop. The quadrature component is used to determine a synchronous power level. A control loop error signal is produced by the difference between the synchronous power level and the wind turbine system power output. Changes in the grid frequency produce an error signal that is added to the power set point of wind turbine system output controllers to provide a power system inertial power output response.

Abstract: A variable speed wind turbine is arranged to provide additional electrical power to counteract non-periodic disturbances in an electrical grid. A controller monitors events indicating a need to increase the electrical output power from the wind turbine to the electrical grid. The controller is arranged to control the wind turbine as follows: after an indicating event has been detected, the wind turbine enters an overproduction period in which the electrical output power is increased, wherein the additional electrical output power is taken from kinetic energy stored in the rotor and without changing the operation of the wind turbine to a more efficient working point. When the rotational speed of the rotor reaches a minimum value, the wind turbine enters a recovery period to re-accelerate the rotor to the nominal rotational speed while further contributing to the stability of the electrical grid by outputting at least a predetermined minimum electrical power.

Abstract: The present invention relates to a power system having a plurality wind turbine generators and a power plant controller arranged to communicate with the plurality of wind turbines generators, where each of the plurality of wind turbine generator being related to a wind turbine controller, the wind turbine controller being arranged to control an active power output in its related wind turbine generator according to an active power set point received from the wind power plant controller; a first subset of wind turbine generators operating at an active power output unrestricted of the active power set point; and a second subset of wind turbine generators operating according to an active power set point; and wherein the wind power plant controller communicates the active power set point, in accordance with the active power output of the first subset of the plurality of wind turbines generators, so as to reduce active power fluctuation of the aggregated active power output of the first and second subset of the plu

Abstract: A variable speed wind turbine is arranged to provide additional electrical power to counteract non-periodic disturbances in an electrical grid. A controller monitors events indicating a need to increase the electrical output power from the wind turbine to the electrical grid. The controller is arranged to control the wind turbine as follows: after an indicating event has been detected, the wind turbine enters an overproduction period in which the electrical output power is increased, wherein the additional electrical output power is taken from kinetic energy stored in the rotor and without changing the operation of the wind turbine to a more efficient working point. When the rotational speed of the rotor reaches a minimum value, the wind turbine enters a recovery period to re-accelerate the rotor to the nominal rotational speed while further contributing to the stability of the electrical grid by outputting at least a predetermined minimum electrical power.