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: A method and associated system for operating a power generation to supply real and reactive power to a grid includes determining a total reactive power demand made on the system during a first, stable grid state. A first reactive power portion of the reactive power demand is supplied by a generator, and a second reactive power portion is supplied by a reactive power compensation device, wherein the second reactive power portion may be greater than the first reactive power portion. Upon detection of a grid fault, the first reactive power portion is increased and the second reactive power portion is decreased.

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: The present application relates to a method for controlling a power system connected to a power grid, including: receiving a reactive power instruction and a measured reactive power from a generator; generating a reactive power error signal based on the difference between the reactive power instruction and the measured reactive power; receiving the reactive power error signal; generating a voltage instruction based on reactive power error signal; generating a voltage droop signal based on a reference reactance and a voltage at a point of common coupling; generating a voltage error signal according to at least one of the voltage instruction or the measured terminal voltage of the generator and the voltage droop signal; and producing a reactive current instruction for the converter power path based on the voltage error signal. The present application also discloses a control system for a power system connected to a power grid and a wind farm.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit for converting a first DC voltage of an input power to a first AC voltage, a contactless power transfer unit for transmitting the input power having the first AC voltage, and a second converting unit for transmitting the power having a second DC voltage corresponding to the first AC voltage to an electric load. Additionally, the wireless power transfer system includes an active voltage tuning unit for controlling the second DC voltage based on a difference between the second DC voltage and a reference voltage and at least one among a difference between the resonant frequency and the constant operating frequency and a difference between a phase angle of the first AC voltage and a phase angle of an AC current.

Abstract: Systems and methods for operating a power system having a doubly fed induction generator are provided. In example implementations, an electrical power system connected to a power grid can include a generator comprising a stator and a rotor, the stator connected to the power grid via a stator power path, and a power converter. The power converter can include a line-side converter coupled to the power grid via a converter power path and a rotor-side converter coupled to a rotor bus of the rotor and the line-side converter via a DC link, the rotor-side converter configured to convert a DC power on the DC link to an AC signal for the rotor bus. The power system can also include an active filter comprising one or more active controlled components, the active filter being coupled in parallel with the rotor-side converter to reduce harmonics of the electrical power system.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit for converting a first DC voltage of an input power to a first AC voltage, a contactless power transfer unit for transmitting the input power having the first AC voltage, and a second converting unit for transmitting the power having a second DC voltage corresponding to the first AC voltage to an electric load. Additionally, the wireless power transfer system includes an active voltage tuning unit for controlling the second DC voltage based on a difference between the second DC voltage and a reference voltage and at least one among a difference between the resonant frequency and the constant operating frequency and a difference between a phase angle of the first AC voltage and a phase angle of an AC current.

Abstract: A power generation system is disclosed. The power generation system includes a doubly-fed induction generator (DFIG) coupled to a variable speed engine and a photo-voltaic (PV) power source. The DFIG includes a generator to generate a first electrical power based at least partially on an operating speed of the variable speed engine. The PV power source may supply a second electrical power to a Direct Current (DC) link between a rotor side converter and a line side converter of the DFIG. The generator and the line side converter are coupled to an electric grid and/or a local electrical load to supply the first electrical power and at least a portion of the second electrical power to the local electrical load.

Abstract: A control method for increasing reactive power generation of a wind turbine having a Doubly-Fed Induction Generator (DFIG) includes obtaining, by a control device having one or more processors and one or more memory devices, wind forecast data of the wind turbine. Further, the method includes generating, by the control device, a real-time thermal model of the DFIG of the wind turbine using the wind forecast data. More specifically, the thermal model defines a thermal capacity for the DFIG that does not exceed system limits. Thus, the method also includes dynamically adjusting, by the control device, a reactive power set point of the DFIG of the wind turbine based on the real-time thermal model.

Abstract: A system for health monitoring of a prime mover coupled to a doubly-fed induction generator is disclosed. The DFIG includes a generator having a rotor winding and a stator winding. The system includes first sensors coupled to the stator winding to generate three-phase stator current signals, and second sensors coupled to the rotor winding to generate three-phase rotor current signals. Furthermore, the system includes a signal processor operably coupled to the first sensors and the second sensors and configured to determine a torque profile of the prime mover based on the three-phase stator current signals and the three-phase rotor current signals. Moreover, the signal processor is configured to detect an anomaly associated with the prime mover if the determined torque profile is abnormal.

Abstract: A system including a converter is disclosed. The converter includes a first switch having one or more first controllable switches coupled in parallel across at least one diode. A first controlling unit is operatively coupled to the converter. The first controlling unit is configured to determine a temperature of the one or more first controllable switches. The first controlling unit is further configured to compare the determined temperature of the one or more first controllable switches with a transition temperature at which a first power loss of the one or more first controllable switches is equal to a second power loss of the at least one diode and control a switching state of the one or more first controllable switches based on the comparison of the determined temperature with the transition temperature.

Abstract: A power generation system (101) is disclosed. The power generation system (101) includes a variable speed engine (106) and a DFIG (108) coupled thereto. The DFIG (108) includes a generator (112), a rotor side converter (114), and a line side converter (116) electrically coupled to the generator (112). The rotor side converter (114) is configured to aid in operating the generator (112) as motor to crank the variable speed engine (106). The power generation system (101) further includes a PV power source (110) and/or an energy storage device (122) electrically coupled to a DC-link (118) between the rotor side converter (114) and the line side converter (116). A method of cranking the variable speed engine is also disclosed.

Abstract: Methods and systems are provided for an engine. A condition of the engine may be diagnosed based on information provided by signals from a generator operationally connected to the engine and/or other signals associated with the engine. Different types of degradation may be distinguished based on discerning characteristics within the information. Thus, a degraded engine component may be identified in a manner that reduces service induced delay.

Abstract: A power generation system is provided. The system includes a prime mover for transforming a first energy to a second energy. The system also includes an induction generator operatively coupled to the prime mover and configured to generate electrical power using the second energy. The system further includes an inverter electrically coupled to the induction generator for controlling a terminal voltage of the induction generator during a grid-loss condition. The system also includes a power dissipating device operatively coupled to the inverter for dissipating power generated by the induction generator during the grid-loss condition.

Abstract: Methods and systems are provided for an engine. A condition of the engine may be diagnosed based on information provided by signals from a generator operationally connected to the engine and/or other signals associated with the engine. Different types of degradation may be distinguished based on discerning characteristics within the information. Thus, a degraded engine component may be identified in a manner that reduces service induced delay.

Abstract: A power conditioning unit used in an electrical system. The power conditioning unit includes a positive bus and a negative bus that are electrically connected to a direct current load to enable supplying direct current electrical power to the direct current load; and a first phase leg, which includes a first diode electrically connected to the positive bus, a first transistor electrically connected to the negative bus, and a first node between the first diode and the first transistor. The first node is electrically connected to an alternating current power source to enable the first phase leg to receive a first phase of alternating current electrical power from the alternating current power source and the first transistor opens and closes to control flow of the first phase through the first phase leg to facilitate generating the direct current electrical power at a target voltage using the alternating current electrical power.

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: An uninterruptable power supply (UPS) system for providing power to a load coupled to a utility power source is provided. The UPS system includes a doubly-fed induction generator (DFIG), a rechargeable energy storage system, a first inverter, and a controller in communication with the DFIG and the first inverter. The DFIG includes a stator and a rotor coupled to the load. The stator and rotor are magnetically coupled together. The DFIG generates an auxiliary power output. The first inverter is coupled between the rotor and the rechargeable energy storage system. The controller detects a power disturbance associated with the utility power source and controls the first inverter to provide an excitation input to the rotor in response to the power disturbance. The DFIG provides the auxiliary power output to the load based on the excitation input.

Abstract: A wind power generation system including a doubly fed induction generator (DFIG) of a wind turbine is presented. The DFIG includes a rotor and a stator, a rotor-side conversion unit coupled to the rotor, a direct current (DC) link, and at least one line-side conversion unit coupled to the rotor-side conversion unit via the DC link and coupled to the stator of the DFIG. The at least one line-side conversion unit includes exactly one first converter, high frequency transformers, and second converters, where each of the second converters is coupled to the first converter via a respective high frequency transformer, and inverters, where each of the inverters is coupled to a respective second converter and includes an alternative current (AC) phase terminal.

Abstract: A wireless power transfer system is disclosed. The wireless power transfer system includes a first converting unit for converting a first DC voltage of an input power to a first AC voltage, a contactless power transfer unit for transmitting the input power having the first AC voltage, and a second converting unit for transmitting the power having a second DC voltage corresponding to the first AC voltage to an electric load. Additionally, the wireless power transfer system includes an active voltage tuning unit for controlling the second DC voltage based on a difference between the second DC voltage and a reference voltage and at least one among a difference between the resonant frequency and the constant operating frequency and a difference between a phase angle of the first AC voltage and a phase angle of an AC current.