General Electric Company

General Electric Renovables Espana, S.l.

Ge Infrastructure Technology, LLC

Fernando Arturo Ramirez Sanchez

Robert Gregory Wagoner

Steven Wade Sutherland

Nathaniel Robert Michener

Igor Berroteran

Cornelius Edward Holliday, Iii

Bacil Shaqqo

Kapil Jha

Joseph Kiran Banda

Govardhan Ganireddy

Edward Wayne Hardwicke, Jr

Mathew Doyle Angel

Talha Haque

Zane Taylor Miller

Nathan Michael Killeen

Rajesh Bhupathi

Alfredo Sebastian Achilles

Jeffrey Alan Melius

Arvind Kumar Tiwari

David Scott Wilmer

Hridya Ittamveettil

Pushkar Chandrakant Chaudhari

Michael Lawton Rodin

Victor Eduardo Tamez Varela

Andreu Casal Vilana

Jr Edward Wayne Hardwicke

Iii Cornelius Edward Holliday

Talha Irfanul Haque

Cornelius Edward Holliday

Edward Wayne Hardwicke

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.

Fault tolerant system and method for continuous skip-fire pulse width modulation for an active neutral point clamped converter

A method includes receiving, via one or more turbine-level controllers, an indication of at least one of a communication loss between the one or more turbine-level controllers and a farm-level controller, a detection of an absence of reactive power regulation by the farm-level controller, or a reactive power command of the farm-level controller being equal to or above a saturation threshold during transitioning between a baseline operational mode and reactive power mode, the reactive power mode being characterized in that only reactive power is generate. Upon receipt of the indication, the method includes adjusting a reactive power response of one or more reactive power regulators of the one or more turbine-level controllers so as to avoid an overshoot reactive power event or an undershoot reactive power event at the point of interconnection.

System and method for adjusting reactive power response of one or more wind turbines of a wind farm during a communications fault

A system and method for pre-charging a DC link of a multi-level power converter, to reduce electrical transients or to decrease a charging current when a converter contactor/disconnect switch is closed, is described. The systems and methods of the present disclosure also provides a new and simplified system for pre-charging a DC link of a multi-level power converter by leveraging a neutral point of a multi-level power converter and a single-line connection to the grid side of the power converter. The DC link charger of the present disclosure, therefore, is capable of reducing the quantity of dedicated superfluous hardware and/or excess resistors, contactors, transformers, fuses, diodes, balancing components, rectifier modules, etc. demanded by conventional systems. Reduced quantities of electronic components and hardware can thereby decrease system costs per unit and lead to significant cost savings.

System and method for pre-charging a DC link of a power converter

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.

System and method for detection of switching device failure conditions in a multi-level power converter

A method for operating a multi-level bridge power converter of an electrical power system connected to a power grid includes providing a plurality of switching devices of the power converter in an active neutral point clamped topology. The method also includes operating the plurality of switching devices in a plurality of operating states such that current simultaneously flows through at least two parallel recovery paths of the plurality of switching devices during operation of the power converter to minimize a commutation path of the current when at least one diode of the plurality of switching devices recovers, thereby reducing parasitic inductance affecting the recovering antiparallel diode or the switch.

Active neutral point clamped switch sequence for parasitic inductance control of a power conversion assembly

A method for operating a multi-level bridge power converter of an electrical power system connected to a power grid includes receiving, via a controller of the power converter, an indication of a transient event occurring in the power grid or the electrical power system. The power converter has a plurality of switching devices arranged in an active neutral point clamped topology. Accordingly, upon receiving the indication, the method includes activating a crowbar algorithm programmed in the controller of the power converter to bifurcate a current received by the power converter into a plurality of different current paths defined by the plurality of switching devices.

Crowbar module for an active neutral point clamped power conversion assembly

A method for operating a multi-level bridge power converter of an electrical power system connected to a power grid includes providing a plurality of switching devices of the power converter in one of a neutral point clamped topology or an active neutral point clamped topology, the plurality of switching devices including a first group and a second group of switching devices. The method also includes providing a multi-state deadtime for the first and second groups of switching devices that changes based on different state transitions of the power converter. Further, the method includes operating the first and second groups of switching devices according to the multi-state deadtime to allow the first group to switch differently than the second group during the different state transitions, thereby decreasing voltage overshoots on the first group during one or more of the different state transitions and providing safe transition between commutation states of the power converter.

System and method for operating multi-level power converter using a multi-state deadtime

A method for operating a multi-level bridge power converter includes providing a plurality of switching devices of the power converter in one of a neutral point clamped topology or an active neutral point clamped topology. The method also includes providing a plurality of deadtimes for the switching devices. Further, the method includes selecting one of the deadtimes for each of the switching devices such that at least two of the switching devices operate according to different deadtimes. Moreover, the method includes operating the switching devices at the selected deadtimes to allow a first group of the switching devices to switch slower than a second group of the switching devices such that the first group of the switching devices satisfy safe operating requirements while the second group of the switching devices switch faster than the first group.

System and method for operating multi-level power converter using multiple deadtimes

A power conversion assembly includes a power converter having a plurality of switching devices, a power source electrically coupled to the power converter, and a direct current (DC) filter circuit bridging the power converter and the power source. The DC filter circuit includes a DC link having a positive rail, a negative rail, and a capacitor bank. The capacitor bank includes a first set of capacitors being a first type of capacitors and a second set of capacitors being a different, second type of capacitors. Each capacitor in the first set of capacitors is positioned closer to a respective switching device of the plurality of switching devices than a corresponding capacitor of the second set of capacitors to minimize impedance between each capacitor in the first set of capacitors and the respective switching device such that a majority of ripple current from the plurality of switching devices passes through the first set of capacitors.

Hybrid capacitor bank for a power conversion assembly

A system and method are provided for controlling low-speed operations of a wind turbine electrically coupled to an electrical grid. The wind turbine includes a generator and a power converter. The generator includes a generator rotor and a generator stator. An operating parameter of the generator rotor is indicative of a low-speed operation of the generator. Accordingly, the crossing of a first threshold by the operating parameter is detected. In response, at least a portion of a required reactive power generation is developed via the generator rotor. The portion is then delivered to the electrical grid via the grid side of the power converter.

System and method for controlling low-speed operations of a wind turbine

A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects a loss of traction of the slip coupling between a generator and a rotor of the drivetrain of the wind turbine. In response to detecting the loss of traction, the controller overrides a generator torque setpoint to alter a rotational speed of the generator. In response to the altered rotational speed of the generator, the traction of the slip coupling is increased. Increasing the traction of the slip coupling facilitates an application of generator torque to the drivetrain of the wind turbine.

System and method for controlling a wind turbine

A system and method are provided for controlling a wind turbine to protect the wind turbine from anomalous operations. Accordingly, in response to receiving data indicative of an anomalous operational event of the wind turbine, the controller initiates an enhanced braking mode for the wind turbine. The enhanced braking mode is characterized by operating the generator at a torque setpoint that generates maximum available torque for a given set of operating conditions. Additionally, the torque setpoint is in excess of a nominal torque limit for the generator.

System and method for controlling a wind turbine to protect the wind turbine from anomalous operations

A system and method are provided for operating a power generating asset electrically coupled to a power grid. The power generating asset includes a power converter having a line-side converter operably coupled to the power grid via a converter contactor. Accordingly, a line-side converter of the power converter is decoupled from the power grid and a controller determines the phase angle of the grid voltage. A switching sequence for a plurality switching devices of the line-side converter is then set in order to develop a pre-charge voltage phase angle at a converter-side terminal of the converter contactor which is in phase with the phase angle of the grid voltage. A portion of the charge of the DC link is then discharged through the line-side converter to develop a pre-charge voltage at the converter-side terminal. Once the in-phase, pre-charge voltage is established at the converter-side terminal, the converter contactor is closed to re-couple the line-side converter to the power grid.

System and method for operating a power generating asset

A method for operating a multi-level bridge power converter of an electrical power system includes connecting a plurality of phases of the power converter to a common terminal at a DC side of the power converter so as to effectively equate the plurality of phases at a common electrical potential. The method may also include monitoring, via a controller, a plurality of devices of the power converter for faults. Upon detection of a fault in one or more of the plurality of devices, the method includes activating, via the controller, one or more protection devices of a crowbar of the power converter to prevent additional faults from occurring in remaining devices of the plurality of devices by diverting energy away from the remaining devices of the plurality of devices.

Selective crowbar response for a power converter to mitigate device failure

A method for controlling a three-level back-to-back voltage source power conversion assembly includes receiving an indication of a DC or AC unbalance occurring in voltage of a DC link. The power conversion assembly has a first power converter coupled to a second power converter via the DC link. In response to receiving the indication, the method includes activating a balancing algorithm that includes determining a deviation of a midpoint voltage of the DC link as a function of a total voltage of the DC link, calculating a voltage compensation needed for pulse-width modulation signals of the power conversion assembly based on the deviation, and coordinating common mode voltage injection from each of the power converters independently at a neutral point of the power conversion assembly based on the voltage compensation, thereby minimizing the at least one of the DC unbalance or the AC unbalance at any given operating condition.

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Salem, VA, United States of America

Fernando Arturo Ramirez Sanchez