Abstract: A power generation system (100, 200, 300, 400) is presented. The power generation system includes a prime mover (102), a doubly-fed induction generator (DFIG) (104) having a rotor winding (126) and a stator winding (122), a rotor-side converter (106), a line-side converter (108), and a secondary power source (110, 401) electrically coupled to a DC-link (128). Additionally, the power generation system includes a control sub-system (112, 212, 312) having a controller, and a plurality of switching elements (130, and 132 or 201). The controller is configured to selectively control switching of one or more switching elements (130, and 132 or 201) based on a value of an operating parameter corresponding to at least one of the prime mover, the DFIG, or the secondary power source to connect the rotor-side converter in parallel to the line-side converter to increase an electrical power production by the power generation system.

Abstract: An electrical power system connectable to a power grid includes a cluster of electrical power subsystems, each of the electrical power subsystems including a power converter electrically coupled to a generator having a generator rotor and a generator stator. Each of the electrical power subsystems defines a stator power path and a converter power path for providing power to the power grid. Each of the electrical power subsystems further includes a transformer. The system further includes a subsystem breaker configured with each of the electrical power subsystems, and a cluster power path extending from each subsystem breaker for connecting the cluster of electrical power subsystems to the power grid. The system further includes a reactive power compensation inverter electrically coupled within the electrical power system, the reactive power compensation inverter operable to increase the reactive power level in the electrical current flowing to the power grid.

Abstract: Power converters for use in wind turbine systems are included. For instance, a wind turbine system can include a full power generator having a stator and a rotor. The generator is configured to provide a low voltage alternating current power on a stator bus of the wind turbine system. The wind turbine system includes a power converter configured to convert the low voltage alternating current power provided on the stator bus to a medium voltage multiphase alternating current output power suitable for provision to the electrical grid. The power converter includes a plurality of conversion modules, each conversion module comprising a plurality of bridge circuits. Each bridge circuit includes a plurality of silicon carbide switching devices coupled in series. Each conversion module is configured to provide a single phase of the medium voltage multiphase alternating current output power on a line bus of the wind turbine system.

Abstract: A hybrid power generation system is presented. The system includes a first power generation subsystem including a prime mover driving a generator including a rotor and a stator, one or more first conversion units coupled to at least one of the rotor and the stator, a first direct current (DC) link, and one or more second conversion units coupled to a corresponding one or more first conversion units via the first DC link. The system includes one or more second power generation subsystems coupled to the first power generation subsystem and one or more power conversion subunits including one or more first bridge circuits coupled to a corresponding one or more second bridge circuits via one or more transformers, where at least one of the one or more second power generation subsystems and the first power generation subsystem includes the one or more power conversion subunits.

Abstract: Systems and methods for operating a cluster transformer operably coupled to cluster of DFIG wind turbines in low-wind conditions are provided. A wind turbine cluster system can include at least one DFIG module, a cluster transformer, and a control device configured to control operation of the cluster transformer based at least in part on a wind parameter. Each DFIG module can include a doubly fed induction generator comprising a rotor configured to generate AC power at a first voltage, a stator configured to generate AC power at a second voltage, and a power conversion system coupled to the rotor to convert power at the first voltage to power at the second voltage. The cluster transformer can be configured to receive power at the second voltage from the at least one DFIG module and convert the power at the second voltage to power at a third voltage.

Abstract: A power generation system (100, 200, 300, 400) is presented. The power generation system includes a prime mover (102), a doubly-fed induction generator (DFIG) (104) having a rotor winding (126) and a stator winding (122), a rotor-side converter (106), a line-side converter (108), and a secondary power source (110, 401) electrically coupled to a DC-link (128). Additionally, the power generation system includes a control sub-system (112, 212, 312) having a controller, and a plurality of switching elements (130, and 132 or 201). The controller is configured to selectively control switching of one or more switching elements (130, and 132 or 201) based on a value of an operating parameter corresponding to at least one of the prime mover, the DFIG, or the secondary power source to connect the rotor-side converter in parallel to the line-side converter to increase an electrical power production by the power generation system.

Abstract: Power converters for use in wind turbine systems are included. For instance, a wind turbine system can include a wind driven doubly fed induction generator having a stator and a rotor. The stator is configured to provide a medium voltage alternating current power on a stator bus of the wind turbine system. The wind turbine system includes a power converter configured to convert a low voltage alternating current power provided by the rotor to a medium voltage multiphase alternating current output power suitable for provision to an electrical grid. The power converter includes a plurality conversion modules. Each conversion module includes a plurality of bridge circuits. Each bridge circuit includes a plurality of silicon carbide switching devices coupled in series. Each conversion module is configured to provide a single phase of the medium voltage multiphase alternating current output power on a line bus of the wind turbine system.

Abstract: Power converters for use in energy systems are included. For instance, an energy system can include an input power source configured to provide a low voltage direct current power. The energy system can include a power converter configured to convert the low voltage direct current power provided by the input power source to a medium voltage multiphase alternating current output power suitable for provision to an alternating current power system. The power converter can include a plurality conversion modules. Each conversion module includes a plurality of bridge circuits. Each bridge circuit includes a plurality of silicon carbide switching devices coupled in series. Each conversion module is configured to provide a single phase of the medium voltage multiphase alternating current output power on a line bus of the energy system.

Abstract: The present disclosure is directed to a method for protecting an electrical power system connected to a power grid. The electrical power system includes at least one cluster of electrical power subsystems. Each of the electrical power subsystems defines a stator power path and a converter power path for providing power to the power grid. The converter power path includes a partial power transformer. The electrical power system further includes a subsystem switch configured with each of the electrical power subsystems and a cluster transformer connecting each cluster of electrical power subsystems to the power grid. A cluster switch is configured with the cluster transformer. A controller is communicatively coupled to each of the plurality of electrical power subsystems. Thus, the controller monitors the electrical power system for faults, and if a fault is detected in the cluster, sends, via one of the subsystem switches or the power converters, a block signal to the cluster switch.

Abstract: Systems and methods for operating a power system having a doubly fed induction generator are provided. In example implementations, a power system can include a power converter. The power converter can include a line-side converter, a DC link, and a rotor-side converter. The rotor-side converter is configured to convert a DC power on the DC link to an AC signal for a rotor bus. The system can include a control system having one or more control devices.

Abstract: An electrical power system connectable to a power grid includes a cluster of electrical power subsystems, each of the electrical power subsystems including a power converter electrically coupled to a generator having a generator rotor and a generator stator. Each of the electrical power subsystems defines a stator power path and a converter power path for providing power to the power grid. Each of the electrical power subsystems further includes a transformer. The system further includes a subsystem breaker configured with each of the electrical power subsystems, and a cluster power path extending from each subsystem breaker for connecting the cluster of electrical power subsystems to the power grid. The system further includes a reactive power compensation inverter electrically coupled within the electrical power system, the reactive power compensation inverter operable to increase the reactive power level in the electrical current flowing to the power grid.

Abstract: The present disclosure is directed to a method for protecting an electrical power system connected to a power grid. The electrical power system includes at least one cluster of electrical power subsystems. Each of the electrical power subsystems defines a stator power path and a converter power path for providing power to the power grid. The converter power path includes a partial power transformer. The electrical power system further includes a subsystem switch configured with each of the electrical power subsystems and a cluster transformer connecting each cluster of electrical power subsystems to the power grid. A cluster switch is configured with the cluster transformer. A controller is communicatively coupled to each of the plurality of electrical power subsystems. Thus, the controller monitors the electrical power system for faults, and if a fault is detected in the cluster, sends, via one of the subsystem switches or the power converters, a block signal to the cluster switch.

Abstract: Systems and methods for operating a cluster transformer operably coupled to cluster of DFIG wind turbines in low-wind conditions are provided. A wind turbine cluster system can include at least one DFIG module, a cluster transformer, and a control device configured to control operation of the cluster transformer based at least in part on a wind parameter. Each DFIG module can include a doubly fed induction generator comprising a rotor configured to generate AC power at a first voltage, a stator configured to generate AC power at a second voltage, and a power conversion system coupled to the rotor to convert power at the first voltage to power at the second voltage. The cluster transformer can be configured to receive power at the second voltage from the at least one DFIG module and convert the power at the second voltage to power at a third voltage.

Abstract: Power converters for use in energy systems are included. For instance, an energy system can include an input power source configured to provide a low voltage direct current power. The energy system can include a power converter configured to convert the low voltage direct current power provided by the input power source to a medium voltage multiphase alternating current output power suitable for provision to an alternating current power system. The power converter can include a plurality conversion modules. Each conversion module includes a plurality of bridge circuits. Each bridge circuit includes a plurality of silicon carbide switching devices coupled in series. Each conversion module is configured to provide a single phase of the medium voltage multiphase alternating current output power on a line bus of the energy system.

Abstract: A hybrid power generation system is presented. The system includes a first power generation subsystem including a prime mover driving a generator including a rotor and a stator, one or more first conversion units coupled to at least one of the rotor and the stator, a first direct current (DC) link, and one or more second conversion units coupled to a corresponding one or more first conversion units via the first DC link. The system includes one or more second power generation subsystems coupled to the first power generation subsystem and one or more power conversion subunits including one or more first bridge circuits coupled to a corresponding one or more second bridge circuits via one or more transformers, where at least one of the one or more second power generation subsystems and the first power generation subsystem includes the one or more power conversion subunits.

Abstract: Power converters for use in wind turbine systems are included. For instance, a wind turbine system can include a full power generator having a stator and a rotor. The generator is configured to provide a low voltage alternating current power on a stator bus of the wind turbine system. The wind turbine system includes a power converter configured to convert the low voltage alternating current power provided on the stator bus to a medium voltage multiphase alternating current output power suitable for provision to the electrical grid. The power converter includes a plurality of conversion modules, each conversion module comprising a plurality of bridge circuits. Each bridge circuit includes a plurality of silicon carbide switching devices coupled in series. Each conversion module is configured to provide a single phase of the medium voltage multiphase alternating current output power on a line bus of the wind turbine system.

Abstract: Power converters for use in wind turbine systems are included. For instance, a wind turbine system can include a wind driven doubly fed induction generator having a stator and a rotor. The stator is configured to provide a medium voltage alternating current power on a stator bus of the wind turbine system. The wind turbine system includes a power converter configured to convert a low voltage alternating current power provided by the rotor to a medium voltage multiphase alternating current output power suitable for provision to an electrical grid. The power converter includes a plurality conversion modules. Each conversion module includes a plurality of bridge circuits. Each bridge circuit includes a plurality of silicon carbide switching devices coupled in series. Each conversion module is configured to provide a single phase of the medium voltage multiphase alternating current output power on a line bus of the wind turbine system.

Abstract: A wind turbine system is provided. In various embodiments, the system includes a nacelle supported by a tower. At least one rotor blade is rotatably connected with the nacelle to capture wind energy. The at least one rotor blade rotates relative to the nacelle for generating electricity. A generator is coupled to the nacelle for converting the wind energy into electrical energy. A transformer-converter assembly comprises a converter and a transformer such that the converter is integrally connected to the transformer. An electrical and control module is electronically coupled to the generator and the transformer-converter assembly.

Abstract: Systems and methods for limiting voltage on an auxiliary bus are described. The voltage-limited auxiliary bus may be comprised of a DC auxiliary bus comprised of a positive conductor and a negative conductor; a chopper, wherein the chopper is normally in a non-conducting state; a resistor in series with the chopper, wherein the chopper and the resistor are connected between the positive conductor and the negative conductor of the DC auxiliary bus; and a chopper control, wherein an overvoltage on the DC auxiliary bus causes the chopper control to cause the chopper to begin conducting and the conducting limits the voltage on the DC auxiliary bus and dissipates energy from the overvoltage.

Abstract: Systems and methods for limiting voltage on an auxiliary bus are described. The voltage-limited auxiliary bus may be comprised of a DC auxiliary bus comprised of a positive conductor and a negative conductor; a chopper, wherein the chopper is normally in a non-conducting state; a resistor in series with the chopper, wherein the chopper and the resistor are connected between the positive conductor and the negative conductor of the DC auxiliary bus; and a chopper control, wherein an overvoltage on the DC auxiliary bus causes the chopper control to cause the chopper to begin conducting and the conducting limits the voltage on the DC auxiliary bus and dissipates energy from the overvoltage.