General Electric Company

Ge Infrastructure Technology, LLC

General Electric Renovables Espana, S.l.

Nathaniel Robert Michener

Fernando Arturo Ramirez Sanchez

Robert Gregory Wagoner

Kapil Jha

Steven Wade Sutherland

Igor Berroteran

Arvind Kumar Tiwari

Bacil Shaqqo

Joseph Kiran Banda

Pushkar Chandrakant Chaudhari

Rajesh Bhupathi

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 for operating a multi-level bridge power converter of an electrical power system connected to a power grid includes receiving a commanded state for one or more switching devices thereof. The method also includes receiving a gate-emitter voltage of one or more of the switching devices. Further, the method includes comparing, via at least one comparator, the gate-emitter voltage of the one or more switching devices to a reference voltage range corresponding to the commanded state of the one or more switching devices. In addition, the method includes determining an actual state of the one or more switching devices based on the comparison. Thus, the method also includes implementing a control action based on the actual state of the one or more switching devices.

System and method for detecting IGBT failure in a multi-level converter using gate-emitter voltage sensing

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.

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Roanoke, VA, United States of America

Nathaniel Robert Michener