Abstract: Provided is a method of assessing rotor temperature during operation of a permanent magnet synchronous machine, including a stator having at least one winding set, the method including: providing reference flux linkage values for different rotor and stator temperature values and current values of an operating winding set; measuring an actual rotor temperature value; measuring an actual stator temperature value; measuring an actual current value of an operating winding set; deriving and storing reference flux linkage values for a given set of operating conditions, in particular, by means of a reference run; deriving a reference flux linkage value (for the measured actual rotor and stator temperature values and the measured actual current value of the operating winding set) using the flux model; obtaining a voltage value; deriving an estimated flux linkage value; deriving a rotor temperature offset; and assessing the rotor temperature based on the rotor temperature offset.

Abstract: Provided is a control arrangement for controlling an electrical machine, including: a fundamental current controller, at least one harmonic flux controller related to a harmonic of an electrical frequency of the electrical machine, a summation system for adding voltage commands to obtain a summed voltage command based on which the electrical machine.

Abstract: Provided is an arrangement for determining an operation parameter reference for controlling a generator side converter portion coupled to a generator, in particular of a wind turbine, the arrangement comprising: an arithmetic element configured to derive a fundamental current error by subtracting a, in particular unfiltered, generator output current from a sum of a fundamental current reference and at least one harmonic current reference; a fundamental current controller adapted to determine a fundamental operation parameter reference based on the fundamental current error; at least one other arithmetic element configured to derive at least one harmonic current error by subtracting a, in particular band pass filtered according to the harmonics, generator output current from the at least one harmonic current reference; at least one harmonic current controller configured to determine at least one harmonic operation parameter reference based on the harmonic current error.

Abstract: Provided is an arrangement for determining an operation parameter reference for controlling a generator side converter portion coupled to a generator, in particular of a wind turbine, the arrangement comprising: an arithmetic element configured to derive a fundamental current error by subtracting a, in particular unfiltered, generator output current from a sum of a fundamental current reference and at least one harmonic current reference; a fundamental current controller adapted to determine a fundamental operation parameter reference based on the fundamental current error; at least one other arithmetic element configured to derive at least one harmonic current error by subtracting a, in particular band pass filtered according to the harmonics, generator output current from the at least one harmonic current reference; at least one harmonic current controller configured to determine at least one harmonic operation parameter reference based on the harmonic current error.

Abstract: A device for connecting an electric power generator to an HVDC transmission system is provided, the device having (a) a first unit for converting an AC output voltage from the electric power generator to a DC input voltage for the HVDC transmission system, the first unit having a transformer and a full-bridge rectifier, and (b) a second unit for generating control voltages and/or control currents in the transformer and/or in the electric power generator, the second unit having a PWM full-bridge converter adapted to receive the AC output voltage from the electric power generator or an AC voltage based on said AC output voltage. Furthermore, a system and a method are provided.

Abstract: A generator for producing electric power, the generator including a generator unit including a stator) and a rotatably supported rotor, wherein the stator includes a first set of windings and a second set of windings, and the rotor is adapted to induce electrical voltage in the first set of windings and in the second set of windings when the rotor is rotated relative to the stator, the generator further includes a first converter coupled to the first set of windings, the first converter being adapted to convert alternating voltage in the first set of windings into an output DC voltage, a DC output coupled to the first converter to receive the output DC voltage, and a second converter coupled to the second set of windings and to the DC output, the second converter being adapted to generate control voltages and/or control currents in the second set of windings, is provided.

Abstract: A device for connecting an electric power generator to an HVDC transmission system is provided, the device having (a) a first unit for converting an AC output voltage from the electric power generator to a DC input voltage for the HVDC transmission system, the first unit having a transformer and a full-bridge rectifier, and (b) a second unit for generating control voltages and/or control currents in the transformer and/or in the electric power generator, the second unit having a PWM full-bridge converter adapted to receive the AC output voltage from the electric power generator or an AC voltage based on said AC output voltage. Furthermore, a system and a method are provided.

Abstract: A generator for producing electric power, the generator including a generator unit including a stator) and a rotatably supported rotor, wherein the stator includes a first set of windings and a second set of windings, and the rotor is adapted to induce electrical voltage in the first set of windings and in the second set of windings when the rotor is rotated relative to the stator, the generator further includes a first converter coupled to the first set of windings, the first converter being adapted to convert alternating voltage in the first set of windings into an output DC voltage, a DC output coupled to the first converter to receive the output DC voltage, and a second converter coupled to the second set of windings and to the DC output, the second converter being adapted to generate control voltages and/or control currents in the second set of windings, is provided.