Abstract: A method for operating a power supply system connected to a grid, the power supply system including a rotor, a doubly-fed induction generator (DFIG), a power conversion assembly, and an active filter. The DFIG includes a generator rotor mechanically connected with the rotor and a generator stator. The power conversion assembly includes a rotor-side power converter. The active filter electrically connected with the generator stator via a stator bus and the rotor-side power converter electrically connected with the generator rotor via a rotor bus. Based on a rotor frequency of the generator rotor, the method determines an expected harmonic frequency for a stator current flowing on the stator bus. An amplitude of the stator current at the expected harmonic frequency is determined via a data set of stator current values. The method controls the active filter based on the amplitude of the stator current at the expected harmonic frequency.

Abstract: A method for controlling an active harmonic filter of an inverter-based resource includes receiving, via a maximum compensation tracker module, a grid feedback signal, determining, via the maximum compensation tracker module, a phase shift signal based, at least in part, on the grid feedback signal, applying, via the maximum compensation tracker module, a phase shift offset signal to the phase shift signal to obtain a modified phase shift signal, determining, via the maximum compensation tracker module, a voltage reference signal for the active harmonic filter based, at least in part, on the grid feedback signal and the modified phase shift signal; and controlling, via the maximum compensation tracker module, the active harmonic filter using the voltage reference signal, wherein the phase shift offset signal ensures that the active harmonic filter injects a current substantially out of phase of a targeted harmonic.

Abstract: A controller-implemented method and system for operating a multi-level bridge power converter connected to a power grid in a fault-tolerant operational mode, the power converter including a first converter coupled to a DC link, the first converter including a plurality of switching devices. The method and system determine an on/off scheme for the switching devices in the first converter when one or more of the switching devices has failed in a shorted state, wherein the on/off scheme is dependent upon phase current direction through the first converter. The phase current direction is indirectly determined by sensing a pole voltage of the first converter and implementing the on/off scheme in the fault-tolerant mode when the pole voltage changes from zero to a +/?value indicating that the phase current through the first converter has switched direction.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit configured to convert a first DC voltage of an input power to an AC voltage. Further, the wireless power transfer system includes a contactless power transfer unit configured to transmit the input power having the AC voltage. Also, the wireless power transfer system includes a second converting unit configured to convert the AC voltage to a second DC voltage and transmit the input power having the second DC voltage to an electric load. Additionally, the wireless power transfer system includes a switching unit configured to decouple the electric load from the contactless power transfer unit if the second DC voltage across the electric load is greater than a first threshold value.

Abstract: The system and method described herein provide grid-forming control of a power generating asset having a double-fed generator connected to a power grid. Accordingly, a stator-frequency error is determined for the generator. The components of the stator frequency error are identified as a torsional component corresponding to a drivetrain torsional vibration frequency and a stator component. Based on the stator component, a power output requirement for the generator is determined. This power output requirement is combined with the damping power command to develop a consolidated power requirement for the generator. Based on the consolidated power requirement, at least one control command for the generator is determined and an operating state of the generator is altered.

Abstract: A method for controlling an active harmonic filter of an inverter-based resource includes receiving, via a maximum compensation tracker module, a grid feedback signal, determining, via the maximum compensation tracker module, a phase shift signal based, at least in part, on the grid feedback signal, applying, via the maximum compensation tracker module, a phase shift offset signal to the phase shift signal to obtain a modified phase shift signal, determining, via the maximum compensation tracker module, a voltage reference signal for the active harmonic filter based, at least in part, on the grid feedback signal and the modified phase shift signal; and controlling, via the maximum compensation tracker module, the active harmonic filter using the voltage reference signal, wherein the phase shift offset signal ensures that the active harmonic filter injects a current substantially out of phase of a targeted harmonic.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit configured to convert a first DC voltage of an input power to an AC voltage. Further, the wireless power transfer system includes a contactless power transfer unit configured to transmit the input power having the AC voltage. Also, the wireless power transfer system includes a second converting unit configured to convert the AC voltage to a second DC voltage and transmit the input power having the second DC voltage to an electric load. Additionally, the wireless power transfer system includes a switching unit configured to decouple the electric load from the contactless power transfer unit if the second DC voltage across the electric load is greater than a first threshold value.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit configured to convert a first DC voltage of an input power to a first AC voltage. Further, the wireless power transfer system includes a contactless power transfer unit configured to receive the input power having the first AC voltage from the first converting unit and transmit the input power. Also, the wireless power transfer system includes a second converting unit configured to receive the input power from the contactless power transfer unit and convert the first AC voltage of the input power to a second DC voltage. Furthermore, the wireless power transfer system includes a switching unit configured to decouple the second converting unit from the contactless power transfer unit if the second DC voltage across the electric load is greater than a first threshold value.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit configured to convert a first DC voltage of an input power to a first AC voltage. Further, the wireless power transfer system includes a contactless power transfer unit configured to receive the input power having the first AC voltage from the first converting unit and transmit the input power. Also, the wireless power transfer system includes a second converting unit configured to receive the input power from the contactless power transfer unit and convert the first AC voltage of the input power to a second DC voltage. Furthermore, the wireless power transfer system includes a switching unit configured to regulate the second DC voltage across the electric load if the second DC voltage across the electric load is greater than a voltage reference value.

Abstract: A method for preventing damage in a bearing of a generator of an electrical power system having a power conversion assembly with a first converter coupled to a second converter, and the power conversion assembly electrically coupled to the generator. Further, the method includes monitoring a phase current and voltage of the first converter. The method also includes calculating a common mode power using the phase current and the voltage of the first converter. Moreover, the method includes comparing the common mode power to a predefined power threshold. The method also includes determining whether the common mode power is indicative of degradation in at least one of a bearing insulation or a ground brush based on the comparison of the common mode power to the predefined power threshold.

Abstract: A method for operating a power supply system connected to a grid, the power supply system including a rotor, a doubly-fed induction generator (DFIG), a power conversion assembly, and an active filter. The DFIG includes a generator rotor mechanically connected with the rotor and a generator stator. The power conversion assembly includes a rotor-side power converter. The active filter electrically connected with the generator stator via a stator bus and the rotor-side power converter electrically connected with the generator rotor via a rotor bus. Based on a rotor frequency of the generator rotor, the method determines an expected harmonic frequency for a stator current flowing on the stator bus. An amplitude of the stator current at the expected harmonic frequency is determined via a data set of stator current values. The method controls the active filter based on the amplitude of the stator current at the expected harmonic frequency.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit configured to convert a first DC voltage of an input power to a first AC voltage. Further, the wireless power transfer system includes a contactless power transfer unit configured to receive the input power having the first AC voltage from the first converting unit and transmit the input power. Also, the wireless power transfer system includes a second converting unit configured to receive the input power from the contactless power transfer unit and convert the first AC voltage of the input power to a second DC voltage. Furthermore, the wireless power transfer system includes a switching unit configured to decouple the second converting unit from the contactless power transfer unit if the second DC voltage across the electric load is greater than a first threshold value.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit configured to convert a first DC voltage of an input power to a first AC voltage. Further, the wireless power transfer system includes a contactless power transfer unit configured to receive the input power having the first AC voltage from the first converting unit and transmit the input power. Also, the wireless power transfer system includes a second converting unit configured to receive the input power from the contactless power transfer unit and convert the first AC voltage of the input power to a second DC voltage. Furthermore, the wireless power transfer system includes a switching unit configured to regulate the second DC voltage across the electric load if the second DC voltage across the electric load is greater than a voltage reference value.

Abstract: A method for operating a multi-level bridge power converter includes arranging a plurality of switching devices including at least four inner switching devices and at least two outer switching devices in an active neutral point clamped topology. The method also includes determining whether any of the switching devices is experiencing a failure condition by implementing a failure detection algorithm. The failure detection algorithm includes generating a blocking state logic signal by comparing a switching device voltage and a threshold reference voltage for each of the switching devices, determining an expected voltage blocking state for each of the switching devices based on gate drive signals of the switching devices and an output current direction, and detecting whether a failure condition is present in any of the switching devices based on the blocking state logic signals and the expected voltage blocking states of the switching devices.

Abstract: A controller-implemented method and system for operating a multi-level bridge power converter connected to a power grid in a fault-tolerant operational mode, the power converter including a first converter coupled to a DC link, the first converter comprising a plurality of switching devices. The method and system determine an on/off scheme for the switching devices in the first converter when one or more of the switching devices has failed in a shorted state, wherein the on/off scheme is dependent upon phase current direction through the first converter. The phase current direction is indirectly determined by sensing a pole voltage of the first converter and implementing the on/off scheme in the fault-tolerant mode when the pole voltage changes from zero to a +/?value indicating that the phase current through the first converter has switched direction.

Abstract: A method for operating a power system connected to a power grid includes providing an active filter in the converter power path. Further, the method includes determining a change in attenuation of harmonics of the power system over a predetermined frequency spectrum that is needed to comply with one or more grid code requirements of the power grid. Thus, the method includes actively controlling, via a controller, the active filter to provide the change to the attenuation of the harmonics of the power system so as to mitigate the harmonics of the power system.

Abstract: A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects a transient grid event and generates a torque command via a drive-train-damper control module. The torque command is configured to establish a default damping level of a torsional vibration resulting from the transient grid event. The controller also determines at least one oscillation parameter relating to the torsional vibration and determines a target generator torque level based thereon. The target generator torque level corresponds to an increased level of damping the torsional vibration relative to the default damping level.

Abstract: A method for mitigating voltage disturbances at a point of interconnection (POI) of a grid-forming inverter-based resource (IBR) due to flicker includes receiving a voltage reference command and a voltage feedback. The voltage feedback contains information indicative of the voltage disturbances at the POI due to the flicker. The method also includes determining a power reference signal for the IBR based on the voltage reference command and the voltage feedback. Moreover, the method includes generating a current vector reference signal based on the power reference signal, the current vector reference signal containing a frequency component of the voltage disturbances. Further, the method includes generating a transfer function of a regulator based on the frequency component to account for the flicker effect. In addition, the method includes generating a current vector based on a comparison of the current vector reference signal and a current vector feedback signal.

Abstract: A method of mitigating high frequency harmonics in an output current of an electrical power system connected to a power grid includes providing an active harmonic filter in a stator power path connecting a stator of the generator to the power grid. Further, the method includes controlling, via a controller, the active harmonic filter to selectively extract a high frequency harmonic component from the output current. The method also includes determining, via the controller, whether the high frequency harmonic component is a positive sequence harmonic or a negative sequence harmonic. Moreover, the method includes compensating, via the controller, for the high frequency harmonic component based on whether the high frequency harmonic component is the positive sequence harmonic or the negative sequence harmonic to mitigate the high frequency harmonics in the output current.

Abstract: A method of mitigating high frequency harmonics in an output current of an electrical power system connected to a power grid includes providing an active harmonic filter in a stator power path connecting a stator of the generator to the power grid. Further, the method includes controlling, via a controller, the active harmonic filter to selectively extract a high frequency harmonic component from the output current. The method also includes determining, via the controller, whether the high frequency harmonic component is a positive sequence harmonic or a negative sequence harmonic. Moreover, the method includes compensating, via the controller, for the high frequency harmonic component based on whether the high frequency harmonic component is the positive sequence harmonic or the negative sequence harmonic to mitigate the high frequency harmonics in the output current.