Abstract: A power generation system, wind turbine, and method of pulse width modulation (PWM) for power converters are disclosed. The method generally includes generating a substantially random distribution of timing values, applying a filter to the random distribution to produce a modified random distribution, and delivering PWM ing signals based on the modified random distribution to the power converters.

Abstract: A method of controlling a wind turbine generator is provided, the wind turbine generator converting mechanical energy to electrical. The method comprises: determining an electromagnetic power reference representing the electromagnetic power generated by the wind turbine generator, wherein the electromagnetic power reference is determined based on a desired output of the wind turbine generator; controlling the electrical power generated by the wind turbine generator using a control signal, wherein the control signal is derived from the electromagnetic power reference and is modified in dependence on an inverse power function of the wind turbine generator by incorporating minimal copper loss constraint and stator voltage limiting constraint such that non-linearity of the wind turbine generator is compensated in the control loop and it operates at its maximum efficiency. One effect of the method is that classical linear control loop design can be employed in spite of the plant being a non-linear identity.

Abstract: A variable speed wind turbine is provided. The variable speed wind turbine comprises a generator, a power converter for converting at least a portion of electrical power generated by the generator, the power converter comprising a generator-side converter, a grid-side converter and a DC (direct current) link therebetween, a power dissipating unit operatively coupled to the DC-link, and a controller. The controller is adapted to receive a request to reduce power output from the wind turbine, determine a feed forward power signal based on a reference generator power and a desired turbine power, and operate the power dissipating unit based on the feed forward power signal.

Abstract: A wind turbine is provided. The wind turbine comprises a generator, a power converter for converting at least a portion of electrical power generated by the generator, an energy dissipating unit and a controller. The power converter comprises a generator-side converter, a grid-side converter and a DC (direct current) link there between. The energy dissipating unit is operatively coupled to the DC-link. The controller is adapted to activate the energy dissipating unit to dissipate energy from the DC-link in response to a shutdown request.

Abstract: A wind turbine is provided. The wind turbine comprises a generator, a power converter for converting at least a portion of electrical power generated by the generator, an energy dissipating unit and a controller. The power converter comprises a generator-side converter, a grid-side converter and a DC (direct current) link there between. The energy dissipating unit is operatively coupled to the DC-link The controller is adapted to activate the energy dissipating unit to dissipate energy from the DC-link in response to a shutdown request.

Abstract: A method of controlling a wind turbine generator is provided, the wind turbine generator converting mechanical energy to electrical. The method comprises: determining an electromagnetic power reference representing the electromagnetic power generated by the wind turbine generator, wherein the electromagnetic power reference is determined based on a desired output of the wind turbine generator; controlling the electrical power generated by the wind turbine generator using a control signal, wherein the control signal is derived from the electromagnetic power reference and is modified in dependence on an inverse power function of the wind turbine generator by incorporating minimal copper loss constraint and stator voltage limiting constraint such that non-linearity of the wind turbine generator is compensated in the control loop and it operates at its maximum efficiency. One effect of the method is that classical linear control loop design can be employed in spite of the plant being a non-linear identity.

Abstract: A method of controlling a wind turbine generator is provided, the wind turbine generator converting mechanical energy to electrical. The method comprises: determining an electromagnetic power reference representing the electromagnetic power generated by the wind turbine generator, wherein the electromagnetic power reference is determined based on a desired output of the wind turbine generator; controlling the electrical power generated by the wind turbine generator using a control signal, wherein the control signal is derived from the electromagnetic power reference and is modified in dependence on an inverse power function of the wind turbine generator by incorporating minimal copper loss constraint and stator voltage limiting constraint such that non-linearity of the wind turbine generator plant is compensated in the control loop and it operates at its maximum efficiency. One effect of the method is that classical linear control loop design can be employed in spite of the plant being a non-linear identity.

Abstract: A variable speed wind turbine is provided. The variable speed wind turbine comprises a generator, a power converter for converting at least a portion of electrical power generated by the generator, the power converter comprising a generator-side converter, a grid-side converter and a DC (direct current) link therebetween, a power dissipating unit operatively coupled to the DC-link, and a controller. The controller is adapted to receive a request to reduce power output from the wind turbine, determine a feed forward power signal based on a reference generator power and a desired turbine power, and operate the power dissipating unit based on the feed forward power signal.

Abstract: A method of controlling a wind turbine generator is provided, the wind turbine generator converting mechanical energy to electrical. The method comprises: determining an electromagnetic power reference representing the electromagnetic power generated by the wind turbine generator, wherein the electromagnetic power reference is determined based on a desired output of the wind turbine generator; controlling the electrical power generated by the wind turbine generator using a control signal, wherein the control signal is derived from the electromagnetic power reference and is modified in dependence on an inverse power function of the wind turbine generator by incorporating minimal copper loss constraint and stator voltage limiting constraint such that non-linearity of the wind turbine generator plant is compensated in the control loop and it operates at its maximum efficiency. One effect of the method is that classical linear control loop design can be employed in spite of the plant being a non-linear identity.

Abstract: A method for validating and initializing a control system for an electrical generator connected to a power converter in a wind turbine. The method may include generating a first parameter value representing control signal for controlling the stator flux of a stator of the electrical generator, measuring a second parameter value specifying an electrical operational characteristic of the electrical generator, and determining an accuracy level of the control signal based on the first parameter value and the second parameter value, wherein the accuracy level of the control signal has to fall within a predefined threshold for the control system to be validated.

Abstract: A method for determining a rotor position of an electrical generator in a wind turbine is described comprising determining a voltage of the electrical generator, determining a rotor position angle estimate based on the voltage of the electrical generator, determining a subsequent rotor position angle estimate through a feedback loop, based on a combination of the voltage of the electrical generator and the rotor position angle estimate. Further, a method to real time track encoder health is described comprising determining the phase angle of a reference voltage, determining the angle difference between the rotor position and the reference voltage, and determining the differentiation of the angle difference.

Abstract: A method for determining a rotor position of an electrical generator in a wind turbine is described comprising determining a voltage of the electrical generator, determining a rotor position angle estimate based on the voltage of the electrical generator, determining a subsequent rotor position angle estimate through a feedback loop, based on a combination of the voltage of the electrical generator and the rotor position angle estimate. Further, a method to real time track encoder health is described comprising determining the phase angle of a reference voltage, determining the angle difference between the rotor position and the reference voltage, and determining the differentiation of the angle difference.

Abstract: A method for determining a rotor position of an electrical generator in a wind turbine is described comprising determining a voltage of the electrical generator, determining a rotor position angle estimate based on the voltage of the electrical generator, determining a subsequent rotor position angle estimate through a feedback loop, based on a combination of the voltage of the electrical generator and the rotor position angle estimate. Further, a method to real time track encoder health is described comprising determining the phase angle of a reference voltage, determining the angle difference between the rotor position and the reference voltage, and determining the differentiation of the angle difference.

Abstract: A variable speed wind turbine connected to a utility grid includes a rotor, having at least one blade, a drive train connected to the rotor, the drive train includes a selection of at least one gear box, and at least one electrical generator, a measuring arrangement establishing at least one rotational speed signal of the drive train, and at least one wind turbine power controller connected to the at least one generator and the utility grid. Furthermore the wind turbine includes at least one resonant controller modifying a power reference value in response to the at least one rotational speed signal. A resonant control system, a method of operating a variable speed wind turbine, use of resonant control system and use of a method in a variable speed wind turbine are also contemplated.

Abstract: A method for validating and initializing a control system for an electrical generator connected to a power converter in a wind turbine. The method may include generating a first parameter value representing control signal for controlling the stator flux of a stator of the electrical generator, measuring a second parameter value specifying an electrical operational characteristic of the electrical generator, and determining an accuracy level of the control signal based on the first parameter value and the second parameter value, wherein the accuracy level of the control signal has to fall within a predefined threshold for the control system to be validated.

Abstract: A method for determining a rotor position of an electrical generator in a wind turbine is described comprising determining a voltage of the electrical generator, determining a rotor position angle estimate based on the voltage of the electrical generator, determining a subsequent rotor position angle estimate through a feedback loop, based on a combination of the voltage of the electrical generator and the rotor position angle estimate. Further, a method to real time track encoder health is described comprising determining the phase angle of a reference voltage, determining the angle difference between the rotor position and the reference voltage, and determining the differentiation of the angle difference.

Abstract: A variable rotational speed wind turbine includes a doubly-fed induction generator, a rotor current controller for controlling the rotor currents of the generator, a compensation mechanism having a computation mechanism, and an input mechanism for providing input to the compensation mechanism, the input being representative of at least the instantaneous angular speed of the rotor of the generator. The computation mechanism is arranged to compute an instantaneous compensation control output in dependency of the instantaneous angular speed of the rotor of the generator and feed the compensation control output to the rotor, and to compute the compensation control output during operation of the wind turbine to compensate at least partly for dependencies on the rotor angular speed of the locations of poles of a generator transfer function, thus making a resulting generator transfer function substantially independent of variations in the rotor angular speed during operation of the wind turbine.

Abstract: A variable speed wind turbine connected to a utility grid includes a rotor, having at least one blade, a drive train connected to the rotor, the drive train includes a selection of at least one gear box, and at least one electrical generator, a measuring arrangement establishing at least one rotational speed signal of the drive train, and at least one wind turbine power controller connected to the at least one generator and the utility grid. Furthermore the wind turbine includes at least one resonant controller modifying a power reference value in response to the at least one rotational speed signal. A resonant control system, a method of operating a variable speed wind turbine, use of resonant control system and use of a method in a variable speed wind turbine are also contemplated.

Abstract: A variable rotational speed wind turbine includes a doubly-fed induction generator, a rotor current controller for controlling the rotor currents of the generator, a compensation mechanism having a computation mechanism, and an input mechanism for providing input to the compensation mechanism, the input being representative of at least the instantaneous angular speed of the rotor of the generator. The computation mechanism is arranged to compute an instantaneous compensation control output in dependency of the instantaneous angular speed of the rotor of the generator and feed the compensation control output to the rotor, and to compute the compensation control output during operation of the wind turbine to compensate at least partly for dependencies on the rotor angular speed of the locations of poles of a generator transfer function, thus making a resulting generator transfer function substantially independent of variations in the rotor angular speed during operation of the wind turbine.