Abstract: Provided is an arrangement for controlling a converter of a power generation system, for example, a wind turbine, the converter being connected to a connection point to a utility grid, the arrangement including: a measurement section adapted to provide measurement values indicative of values of current and voltage at the connection point, a main converter controller adapted to receive the measurement values and to generate a main converter control signal based on the measurement values, an active filter system adapted to receive the measurement values and to generate an active filter control signal based on the measurement values, an addition element adapted to add the main converter control signal and the active filter control signal and to supply the sum signal as a control signal to the converter.

Abstract: A method to reduce harmonics in the electrical output (i.e. voltage and current) of a power plant is provided. The power plant is connected via a point of common coupling with an electrical grid. Converters of the power plant provide respective electrical converter output by an applied pulse-width modulation scheme, which is used in the respective converter. The electrical output of the respective converters is summed to generate the electrical output of the power plant. The electrical output of the power plant is provided via the point of common coupling to the electrical grid. Carrier sideband harmonics, which are generated by the converters, are measured in the electrical output of the power plant. A carrier signal of at least one selected converter is adjusted in its phase until specified and characteristic harmonics in the electrical output of the power plant are reduced below a given threshold.

Abstract: Provided is an arrangement for controlling a converter of a power generation system, for example, a wind turbine, the converter being connected to a connection point to a utility grid, the arrangement including: a measurement section adapted to provide measurement values indicative of values of current and voltage at the connection point, a main converter controller adapted to receive the measurement values and to generate a main converter control signal based on the measurement values, an active filter system adapted to receive the measurement values and to generate an active filter control signal based on the measurement values, an addition element adapted to add the main converter control signal and the active filter control signal and to supply the sum signal as a control signal to the converter.

Abstract: A method to reduce harmonics in the electrical output (i.e. voltage and current) of a power plant is provided. The power plant is connected via a point of common coupling with an electrical grid. Converters of the power plant provide respective electrical converter output by an applied pulse-width modulation scheme, which is used in the respective converter. The electrical output of the respective converters is summarized to generate the electrical output of the power plant. The electrical output of the power plant is provided via the point of common coupling to the electrical grid. Carrier sideband harmonics, which are generated by the converters, are measured in the electrical output of the power plant. A carrier signal of at least one selected converter is adjusted in its phase until specified and characteristic harmonics in the electrical output of the power plant are reduced below a given threshold.

Abstract: Disclosed is a method of controlling the power input to a HVDC transmission link, which HVDC transmission link is connected to an AC power plant via a first voltage source converter and to AC grid via a second voltage source converter, which method includes using the second voltage source converter to perform voltage control of the HVDC transmission link during a no-fault mode of operation of the grid; monitoring a HVDC transmission link parameter to detect an unbalanced fault; and using the first voltage source converter to regulate the output of the AC power plant on the basis of the monitored HVDC transmission link parameter in the event of an unbalanced fault. Also described are a control module for controlling the power input to a HVDC transmission link; a voltage source converter for a power plant; and a power generation and transmission arrangement.

Abstract: A power generator park provided, which includes at least two power generator devices. Each power generator device has a switching converter for providing an electrical output power. A central controller is provided for providing switching parameter settings to the switching converters. Each of the at least two power generator devices further includes a timing unit for receiving a common time signal. The switching converter of each of the at least two power generator devices is configured for controlling at least one switching parameter in response to the respective switching parameter setting with a temporal coordination based on the common time signal.

Abstract: Disclosed is a method of controlling the power input to a HVDC transmission link, which HVDC transmission link is connected to an AC power plant via a first voltage source converter and to AC grid via a second voltage source converter, which method includes using the second voltage source converter to perform voltage control of the HVDC transmission link during a no-fault mode of operation of the grid; monitoring a HVDC transmission link parameter to detect an unbalanced fault; and using the first voltage source converter to regulate the output of the AC power plant on the basis of the monitored HVDC transmission link parameter in the event of an unbalanced fault. Also described are a control module for controlling the power input to a HVDC transmission link; a voltage source converter for a power plant; and a power generation and transmission arrangement.

Abstract: A method for controlling a DC-transmission link for transmitting electric power from a power production unit connected to an AC-DC converter at a first side of the DC-transmission link to a utility grid connected to a DC-AC converter at a second side of the DC-transmission link is provided. The method includes: obtaining a DC voltage signal indicative of a DC voltage at the DC transmission link; controlling the AC-DC converter such that an AC voltage at an AC side of the AC-DC converter is adjusted based on the DC voltage signal. Further, an apparatus for controlling a DC-transmission link is provided.

Abstract: A power generator park provided, which includes at least two power generator devices. Each power generator device has a switching converter for providing an electrical output power. A central controller is provided for providing switching parameter settings to the switching converters. Each of the at least two power generator devices further includes a timing unit for receiving a common time signal. The switching converter of each of the at least two power generator devices is configured for controlling at least one switching parameter in response to the respective switching parameter setting with a temporal coordination based on the common time signal.