Abstract: A system and method are provided for operating a power generating asset. Accordingly, a controller detects a fault condition impacting the power generating asset. The controller then determines whether the fault condition is occurring in the power generating asset or is occurring in the power grid. When the fault condition is occurring in the power generating asset, a first response control scheme is implemented. However, when the fault condition is occurring in the power grid, a second response control scheme is implemented. The response control schemes include a first current threshold and a second current threshold respectively, with first current threshold being less than the second current threshold. Additionally, a control action is implemented in response to an approach of a current to the respective current threshold.

Abstract: 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.

Abstract: A method for controlling a power converter of a wind turbine power system connected to an electrical grid. The wind turbine power system has a generator and the power converter has rotor-side converter and a line-side converter. The method includes monitoring an electrical parameter of at least one of the wind turbine power system or the electrical grid. In response to detecting a transient event in the electrical grid, the method includes temporarily disabling the line-side converter of the power converter from the electrical grid. Either during the transient event or after the transient event is over, the method includes implementing a control action for the line-side converter of the power converter. Further, the method includes enabling the line-side converter of the power converter to the electrical grid.

Abstract: 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.

Abstract: A system and method are provided for operating a power generating asset. Accordingly, a controller detects a fault condition impacting the power generating asset. The controller then determines whether the fault condition is occurring in the power generating asset or is occurring in the power grid. When the fault condition is occurring in the power generating asset, a first response control scheme is implemented. However, when the fault condition is occurring in the power grid, a second response control scheme is implemented. The response control schemes include a first current threshold and a second current threshold respectively, with first current threshold being less than the second current threshold. Additionally, a control action is implemented in response to an approach of a current to the respective current threshold.

Abstract: A method for controlling a power converter of a wind turbine power system connected to an electrical grid. The wind turbine power system has a generator and the power converter has rotor-side converter and a line-side converter. The method includes monitoring an electrical parameter of at least one of the wind turbine power system or the electrical grid. In response to detecting a transient event in the electrical grid, the method includes temporarily disabling the line-side converter of the power converter from the electrical grid. Either during the transient event or after the transient event is over, the method includes implementing a control action for the line-side converter of the power converter. Further, the method includes enabling the line-side converter of the power converter to the electrical grid.

Abstract: Systems and methods for allocating reactive power production in a doubly-fed induction generator (DFIG) wind turbine system including a DFIG and a power converter including a line side converter and a rotor side converter are provided. A method can include obtaining a reactive power production requirement, obtaining one or more operating parameters for the DFIG and the line side converter, and determining a priority ratio based at least in part on the one or more operating parameters. The priority ratio can be a ratio of reactive power production between the DFIG and the line side converter. The method can further include controlling the DFIG and the line side converter based at least in part on the reactive power production requirement and the priority ratio such that the combined reactive power production from the DFIG and the line side converter meet the reactive power production requirement.

Abstract: Systems and methods for allocating reactive power production in a doubly-fed induction generator (DFIG) wind turbine system including a DFIG and a power converter including a line side converter and a rotor side converter are provided. A method can include obtaining a reactive power production requirement, obtaining one or more operating parameters for the DFIG and the line side converter, and determining a priority ratio based at least in part on the one or more operating parameters. The priority ratio can be a ratio of reactive power production between the DFIG and the line side converter. The method can further include controlling the DFIG and the line side converter based at least in part on the reactive power production requirement and the priority ratio such that the combined reactive power production from the DFIG and the line side converter meet the reactive power production requirement.

Abstract: The present disclosure is directed to an electrical cabinet for an electrical assembly for a wind turbine. The electrical cabinet has one or more walls that define an internal volume having one or more electrical components configured therein. One or more of the walls includes an inner panel and an outer panel mounted to the inner panel. The inner panel includes an inner vent and the outer panel includes an outer vent. Further, the panels are arranged together so as to define a flow path between the inner and outer vents. Thus, during normal operation, air is directed from outside of the electrical cabinet to the internal volume of the electrical cabinet via the flow path so as to cool the one or more electrical components. Further, during a fault event, gas is permitted to exit the internal volume of the electrical cabinet via the flow path.

Abstract: The present disclosure is directed to an electrical cabinet for an electrical assembly for a wind turbine. The electrical cabinet has one or more walls that define an internal volume having one or more electrical components configured therein. One or more of the walls includes an inner panel and an outer panel mounted to the inner panel. The inner panel includes an inner vent and the outer panel includes an outer vent. Further, the panels are arranged together so as to define a flow path between the inner and outer vents. Thus, during normal operation, air is directed from outside of the electrical cabinet to the internal volume of the electrical cabinet via the flow path so as to cool the one or more electrical components. Further, during a fault event, gas is permitted to exit the internal volume of the electrical cabinet via the flow path.

Abstract: A power converter system includes a converter configured to be coupled to a power generation unit for receiving current from the power generation unit. A bus is coupled to the converter, and energy is stored within the bus when the current is conducted through the power converter system. A damping circuit is configured to be coupled to the bus and to the power generation unit, and a control system is coupled to the converter and to the damping circuit. The control system is configured to selectively discharge at least a portion of the energy stored within the bus through the damping circuit when the control system determines that a predetermined condition is met.

Abstract: A power converter system includes a converter configured to be coupled to a power generation unit for receiving current from the power generation unit. A bus is coupled to the converter, and energy is stored within the bus when the current is conducted through the power converter system. A damping circuit is configured to be coupled to the bus and to the power generation unit, and a control system is coupled to the converter and to the damping circuit. The control system is configured to selectively discharge at least a portion of the energy stored within the bus through the damping circuit when the control system determines that a predetermined condition is met.

Abstract: Systems and methods for improving low-load efficiency of power converters are provided. The power converter can include one or more bridge circuits having multiple switching modules, such as insulated gate bipolar transistor (IGBT) modules, connected in parallel within the same bridge circuit. The power converter is configured to convert power from an input power source, such as a photovoltaic array or a wind turbine, into output power at a grid frequency. To avoid excessive switching losses at low load conditions, the power converter can be controlled to selectively operate a subset of the switching modules within the same bridge circuit based on a load condition for the power converter. The remaining switching modules in the bridge circuit can be disabled.

Abstract: A system and method for reducing reactive current in burn-in test systems for solar power converters is disclosed. An emulator configured to simulate a DC power source and the power converter subject to the burn-in test can be coupled in a two-unit circulating configuration. An AC feeder line configured to supply power to the two-unit circulating configuration. A controller can be configured to adjust the output of one or more of the emulator and power converter to reduce reactive current flowing in the AC feeder line. For instance, the controller can adjust the modulation of switching devices used in the power converter or emulator to adjust the power factor of various components of the burn-in test system to compensate for the reactive current in the AC feeder line.

Abstract: A fault protection scheme for a photovoltaic power converter system is provided. According to aspects of the present disclosure, a fault protection circuit is coupled between a power converter and a ground reference. The fault protection circuit includes a fuse and a current sensor coupled in series with the fuse. A controller is configured to receive current readings from the current sensor and compare the current readings to a current threshold. The current threshold is selected to be less than the fuse current rating of the fuse. The controller identifies a fault condition if the current flowing through the ground protection circuit exceeds the current threshold value. A contactor can also be provided to temporarily lift the power converter relative to the ground reference to determine the existence of other fault paths in the system.

Abstract: A power converter includes a plurality of direct current (DC) conduits and a precharging and clamping circuit coupled to the DC conduits. The precharging and clamping circuit includes at least one diode, at least one switching device coupled in parallel with the diode, and at least one contactor device coupled to an alternating current (AC) source and the diode. The at least one contactor device is configured to facilitate alternating said precharging and clamping circuit between precharging operation and voltage clamping operation.