Abstract: A wind turbine park (242) connected to a transmission system (234). The wind turbine park includes a component (230) for determining a short circuit ratio and based thereon for determining a parameter adjustment recipe, and a controller (238) for controlling an output of the wind turbine park, the controller (238) executing a control algorithm using a determined parameter adjustment recipe, the determined parameter adjustment recipe responsive to the short circuit ratio and determined within the component (230) or within the controller (238).

Abstract: A power generation and transmission system, including: a wind turbine having an electrical generator (12) producing AC electrical power at a production frequency; a converter connected to the electrical generator (12) and configured to convert the AC electrical power to a transmission frequency below a grid frequency; an insulated transmission cable (18) connected to the converter and disposed at least partly submarine or subterranean; and a synchronous frequency converter (24) remote from the wind turbine and configured to receive the AC electrical power from the insulated transmission cable (18) and to convert it to the grid frequency for supply to a grid.

Abstract: A method and a controller for continuously operating a plurality of electric energy generating machines during a high voltage condition at a point of common coupling of the plurality of electric energy generating machines are provided herein. The method includes a) sensing a voltage level at the point of common coupling exceeding a permitted voltage level; b) curtailing an active power output of the plurality of electric energy generating machines such that a reactive capability of the plurality of electric energy generating machines is increased; c) establishing a set point of an electric quantity being present at the point of common coupling such that a reactive electric component providable by the electric energy generating machines is increased; and d) controlling an electric energy generating machine based on the set point of the electric quantity such that the high voltage condition at common coupling is at least partially remedied.

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 of operating a wind park having a plurality of wind turbines is provided. The method includes determining a grid condition indicator indicative of the condition of a grid into which the wind park feeds; determining a first maximum power value of the wind park on the basis of the grid condition indicator; determining an operating margin on the basis of the grid condition indicator, for a grid condition indicator indicative of a weak grid; determining a second maximum power value on the basis of the operating margin; and curtailing the active power output of the wind park according to a maximum power value. A computer program product for carrying out the steps of such a method; an active power controller adapted for use in operating a wind turbine of a wind park; a wind turbine; and a wind park are also provided.

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: An apparatus for compensating a power system transmission line (46). The apparatus comprises an autotransformer (40) disposed in series with the transmission line (46). An autotransformer series winding (40A) extends from an input terminal (46) to a neutral terminal (44) and a common winding (40B) extends from an output terminal (54) to the neutral terminal (44). A compensating device (42) is connected between the neutral terminal (44) and ground. Although connected in shunt with the transmission line (46), the compensating device (42) operates as a series-connected compensating device relative to the transmission line (46). The autotransformer (40) can be connected in a buck or a boost configuration with a fixed or moveable winding tap (88). Also, two autotransformers (110, 114) can be connected in a back-to-back configuration with the compensating device (42) connected to either autotransformer (110, 114).

Abstract: A power generating device (2, 3) for supplying power to a power system (37). The power generating device includes a first component (87) for generating a first signal representing a frequency of a voltage on the power system, a power converter (90) for generating an output voltage, a second component (82) responsive to the first signal and to a second signal representing the output voltage, the second component producing an error signal representing a phase angle difference between the first and second signals, and the error signal being an input to the power converter for controlling the power converter to maintain the phase angle difference between the output voltage and the first signal.

Abstract: A wind turbine generator park (1) for supplying power to a power system (37), the park having an assigned first droop response characteristic for use in responding to an under-frequency occurrence on the power system (37). The park comprises a first comparator (108) for generating a first signal when the park is operating according to a curtailed condition, a second comparator (100) for indicating that a change in a frequency of a voltage or current on the power system (37) is greater than a first threshold value, and a controller (114) responsive to the first and second signals for controlling the park according to a second response characteristic causing the park (1) to supply an amount of power to the power system (37) greater than the power supplied according to the first droop response characteristic.

Abstract: A method and system for controlling the output power from a renewable energy installation (10) to a utility grid (56) having a predetermined bound for a variation in output power per unit of time is provided. The method and system includes constraining an output signal of a controller (76) to an upper and/or lower limit via a limiter (78), wherein the upper and/or lower limit comprises a predetermined upper and/or lower bound for a variation in output power per unit of time. The constrained output signal is then applied to the plurality of electricity generators (12, 14, 16) to limit the variation in output power per unit of time according to the predetermined bound.

Abstract: A method for controlling an amount of power delivered by a power source (16) to a power line (32). An energy storage unit (38) receives portions of energy generated by the source and provides stored energy to supplement power output from the source to the power line. Maximum and minimum limits define a range of change in the power delivered to the power line by the power subsystem. An amount of power to be delivered by each of the source and the energy storage unit to the power line is based on (i) a determined amount of power available for delivery directly to the power line from the power source, (ii) a determined level of energy in the storage unit available for delivery to the power line, and (iii) the limits in the range of change in the power to be delivered by the power source to the power line.

Abstract: A wind turbine park (242) connected to a transmission system (234). The wind turbine park includes a component (230) for determining a short circuit ratio and based thereon for determining a parameter adjustment recipe, and a controller (238) for controlling an output of the wind turbine park, the controller (238) executing a control algorithm using a determined parameter adjustment recipe, the determined parameter adjustment recipe responsive to the short circuit ratio and determined within the component (230) or within the controller (238).

Abstract: A power generation and transmission system, including: a wind turbine having an electrical generator (12) producing AC electrical power at a production frequency; a converter connected to the electrical generator (12) and configured to convert the AC electrical power to a transmission frequency below a grid frequency; an insulated transmission cable (18) connected to the converter and disposed at least partly submarine or subterranean; and a synchronous frequency converter (24) remote from the wind turbine and configured to receive the AC electrical power from the insulated transmission cable (18) and to convert it to the grid frequency for supply to a grid.

Abstract: A full converter connected to a series compensated transmission line. The full converter comprises a generator side converter, a DC link connected across an output of the generator side converter, a line side converter connected across an output of the DC link, and a converter controller configured to control the full converter to mitigate effects of subsynchronous oscillations present on the series compensated transmission line.

Abstract: Pharmaceutical formulations and methods including an immune response modifier (IRM) compound and an oleic acid component are provided where stability is improved by using oleic acid have low polar impurities such as peroxides.

Abstract: An apparatus for compensating a power system transmission line (46). The apparatus comprises an autotransformer (40) disposed in series with the transmission line (46). An autotransformer series winding (40A) extends from an input terminal (46) to a neutral terminal (44) and a common winding (40B) extends from an output terminal (54) to the neutral terminal (44). A compensating device (42) is connected between the neutral terminal (44) and ground. Although connected in shunt with the transmission line (46), the compensating device (42) operates as a series-connected compensating device relative to the transmission line (46). The autotransformer (40) can be connected in a buck or a boost configuration with a fixed or moveable winding tap (88). Also, two autotransformers (110, 114) can be connected in a back-to-back configuration with the compensating device (42) connected to either autotransformer (110, 114).

Abstract: A method for controlling an amount of power delivered by a power source (16) to a power line (32). An energy storage unit (38) receives portions of energy generated by the source and provides stored energy to supplement power output from the source to the power line. Maximum and minimum limits define a range of change in the power delivered to the power line by the power subsystem. An amount of power to be delivered by each of the source and the energy storage unit to the power line is based on (i) a determined amount of power available for delivery directly to the power line from the power source, (ii) a determined level of energy in the storage unit available for delivery to the power line, and (iii) the limits in the range of change in the power to be delivered by the power source to the power line.

Abstract: A wind turbine controlled to damp subsynchronous resonance oscillations on a grid is provided. The wind turbine includes rotor blades for turning by the wind, an electric generator rotatably coupled to the rotor blades, a power converter responsive to electricity generated by the electric generator, the power converter for converting the generated electricity to a frequency and voltage suitable for supply to the power grid, and the power converter for regulating voltage on the grid for damping the subsynchronous oscillations. Additionally, in one embodiment voltage regulation is supplemented by modulating real power to damp the subsynchronous oscillations.

Abstract: A full converter connected to a series compensated transmission line. The full converter comprises a generator side converter, a DC link connected across an output of the generator side converter, a line side converter connected across an output of the DC link, and a converter controller configured to control the full converter to mitigate effects of subsynchronous oscillations present on the series compensated transmission line.

Abstract: A wind farm (10) may include a plurality of variable speed wind turbines (12, 14, 16). A centralized controller (50) may be configured to selectively adjust a respective electrical output power from each of the wind turbines. The controller may include a monitor (52) configured to monitor a correlation between a deviation from a grid frequency and a wind power change. The controller may be configured to adjust a response of the electrical output power based on the monitored correlation. The electrical output power response may be configured to meet a grid frequency regulation notwithstanding of random occurrences of wind power changes.