Abstract: A system and method are provided for performing reactive power control. The system includes a power converter and a controller coupled to the power converter. The power converter is configured to convert a first form of electric power generated from the power source to a second form of electric power suitable to be distributed by the electrical grid. The controller is configured to monitor the electric power transmitted between the power converter and the electrical grid. The controller is further configured to decouple a positive sequence component and a negative sequence component from the monitored electric power. The controller is further configured to perform a positive reactive power control and a negative reactive power control with respect to the decoupled positive and negative sequence components. The controller is further configured to transmit a control signal to the power converter based on the positive and negative reactive power control.

Abstract: A power limiter system is described. The power limiter system is configured to receive a phase locked loop (PLL) error signal; analyze the PLL error signal to identify an occurrence of a grid contingency event; generate a first power command signal corresponding to an occurrence of the grid contingency event; and, transmit the first command signal to a converter interface controller. The system further includes a memory configured to store at least one variable that corresponds to the PLL error signal upon identification of an occurrence of the grid contingency event.

Abstract: A system for improving wind turbine generator performance is disclosed. In one aspect a rotary power generation system is provided, including: a rotary power generator for generating variable-frequency alternating currents; a negative sequence current regulator that determines and uses frequency-dependent D-axis and Q-axis negative sequence gains based on an electrical frequency of the rotary power generator; and a system for controlling voltage components for balancing the variable-frequency alternating currents generated by the rotary power generator based on the selected D-axis and Q-axis negative sequence gains.

Abstract: A fault detection system is provided, and includes a generator, a power converter, a breaker, a current monitoring device, and a control module. The power converter is selectively connected to the generator and is selectively activated to produce a test voltage. The breaker is located between the generator and the power converter for selectively connecting the generator to the power converter. The breaker includes an open position and a closed position. The current monitoring device is located between the generator and the power converter. The current monitoring device measures a line current between the generator and the power converter. The control module is in communication with the current monitoring device and the power converter. The control module has a memory with a threshold current value.

Abstract: A permanent magnet (PM) machine system is provided having a PM machine and a controller in communication with the PM machine. The PM machine has a q-axis voltage feedback signal and a pullout torque that represents a peak torque that the PM machine generates. The controller includes a q-axis current regulator that produces a commanded q-axis voltage that is supplied to the PM machine. The controller also includes at least one control logic for monitoring the q-axis voltage feedback signal of the PM machine.

Abstract: A power converter for a wind turbine including an array of switching devices and a control module having a current damping device. The control module is configured to control a switching behavior of the array of switching devices and to receive a current having a first frequency component from the wind turbine. The current damping device is configured to reduce an amplitude of the first frequency component.

Abstract: In an embodiment, the circuit includes: a first switch serially connected to a first discharge resistor, the first switch and the first discharge resistor connected to a positive DC bus; a second switch serially connected to a second discharge resistor, the second switch and the second discharge resistor connected to a negative DC bus; and a capacitor bank for storing a positive and a negative DC voltage, the capacitor bank including a first capacitor in parallel with the first switch and the first discharge resistor, and a second capacitor in parallel with the second switch and the second discharge resistor, wherein the first switch operates independently from the second switch to discharge the positive DC voltage through the first discharge resistor and the second switch operates independently from the first switch to discharge the negative DC voltage through the second discharge resistor.

Abstract: A method for controlling operation of a wind turbine included within a power generation and delivery system is described. The method includes measuring at least one operating condition of the power generation and delivery system. The method also includes transmitting, to a power limiter system, an operating condition feedback signal that corresponds to the operating condition. The method also includes analyzing the operating condition feedback signal to identify an occurrence of a grid contingency event and generating a real current command signal corresponding to an occurrence of a grid contingency event. The method also includes transmitting the real current command signal to a controller and applying the real current command signal to power converter performance to facilitate reducing pole-slipping. The method also includes storing, in a memory, at least one variable corresponding to the operating condition upon the occurrence of a grid contingency event.

Abstract: Systems, methods, and apparatus for supplying AC power to an AC power grid from a DC power source, such as a photovoltaic (PV) array are disclosed. The systems and methods can include a converter coupled to the DC power source that provides DC power to a DC bus at a DC bus voltage. The systems and methods can further include an inverter coupled to the DC bus for converting the DC power of the DC bus to an output AC power. The systems and methods can further include a control system configured to regulate the DC bus voltage of the DC bus to operate at a variable DC bus voltage setpoint. The control system can adjust the DC bus voltage setpoint based at least in part on the DC bus voltage and the output AC current of the inverter.

Abstract: A method for controlling operation of a wind turbine included within a power generation and delivery system is described. The method includes measuring at least one operating condition of the power generation and delivery system. The method also includes transmitting, to a power limiter system, an operating condition feedback signal that corresponds to the operating condition. The method also includes analyzing the operating condition feedback signal to identify an occurrence of a grid contingency event and generating a real current command signal corresponding to an occurrence of a grid contingency event. The method also includes transmitting the real current command signal to a controller and applying the real current command signal to power converter performance to facilitate reducing pole-slipping. The method also includes storing, in a memory, at least one variable corresponding to the operating condition upon the occurrence of a grid contingency event.

Abstract: A control system for a wind turbine, the control system having at least one measurement device configured to measure at least one operating condition of the wind turbine and a first controller. The first controller is configured to calculate an operating limit of the wind turbine based on the measured operating condition and to adjust the operating limit based on a limiting condition of a component of the wind turbine.

Abstract: In an embodiment, the circuit includes: a first switch serially connected to a first discharge resistor, the first switch and the first discharge resistor connected to a positive DC bus; a second switch serially connected to a second discharge resistor, the second switch and the second discharge resistor connected to a negative DC bus; and a capacitor bank for storing a positive and a negative DC voltage, the capacitor bank including a first capacitor in parallel with the first switch and the first discharge resistor, and a second capacitor in parallel with the second switch and the second discharge resistor, wherein the first switch operates independently from the second switch to discharge the positive DC voltage through the first discharge resistor and the second switch operates independently from the first switch to discharge the negative DC voltage through the second discharge resistor.

Abstract: A method for controlling operation of a wind turbine included within a power generation and delivery system is described. The method includes measuring at least one operating condition of the power generation and delivery system. The method also includes transmitting, to a power limiter system, an operating condition feedback signal that corresponds to the operating condition. The method also includes analyzing the operating condition feedback signal to identify an occurrence of a grid contingency event and generating a real current command signal corresponding to an occurrence of a grid contingency event. The method also includes transmitting the real current command signal to a controller and applying the real current command signal to power converter performance to facilitate reducing pole-slipping. The method also includes storing, in a memory, at least one variable corresponding to the operating condition upon the occurrence of a grid contingency event.

Abstract: A power converter for a wind turbine including an array of switching devices and a control module having a current damping device. The control module is configured to control a switching behavior of the array of switching devices and to receive a current having a first frequency component from the wind turbine. The current damping device is configured to reduce an amplitude of the first frequency component.

Abstract: Systems, methods, and apparatus for supplying AC power to an AC power grid from a DC power source, such as a photovoltaic (PV) array are disclosed. The systems and methods can include a converter coupled to the DC power source that provides DC power to a DC bus at a DC bus voltage. The systems and methods can further include an inverter coupled to the DC bus for converting the DC power of the DC bus to an output AC power. The systems and methods can further include a control system configured to regulate the DC bus voltage of the DC bus to operate at a variable DC bus voltage setpoint. The control system can adjust the DC bus voltage setpoint based at least in part on the DC bus voltage and the output AC current of the inverter.

Abstract: Systems, methods, and apparatus for supplying AC power to an AC power grid from a DC power source, such as a photovoltaic (PV) array are disclosed. The systems and methods can include a converter coupled to the DC power source that provides DC power to a DC bus at a DC bus voltage. The systems and methods can further include an inverter coupled to the DC bus for converting the DC power of the DC bus to an output AC power. The systems and methods can further include a control system configured to regulate the DC bus voltage of the DC bus to operate at a variable DC bus voltage setpoint. The control system can adjust the DC bus voltage setpoint based at least in part on the DC bus voltage and the output AC current of the inverter.

Abstract: A method of assembling an electrical machine includes programming at least one processor with a stator flux vector estimation scheme. The electrical machine has a stator at least partially extending around a rotor. The electrical machine is electrically coupled to an electric power system. The electric power system transmits at least one phase of electric power to and from the electrical machine with at least partial power conversion. The stator flux vector estimation scheme is programmed to generate at least one stator back-electromagnetic force (back-EMF) signal and to generate at least one stator flux vector signal using the at least one stator back-EMF signal. The at least one stator flux vector signal at least partially represents an estimated rotor position. The method also includes coupling at least one output device in data communication with the at least one processor.

Abstract: A control system for a wind turbine, the control system having at least one measurement device configured to measure at least one operating condition of the wind turbine and a first controller. The first controller is configured to calculate an operating limit of the wind turbine based on the measured operating condition and to adjust the operating limit based on a limiting condition of a component of the wind turbine.

Abstract: Systems, methods, and apparatus for supplying AC power to an AC power grid from a DC power source, such as a photovoltaic (PV) array are disclosed. The systems and methods can include a converter coupled to the DC power source that provides DC power to a DC bus at a DC bus voltage. The systems and methods can further include an inverter coupled to the DC bus for converting the DC power of the DC bus to an output AC power. The systems and methods can further include a control system configured to regulate the DC bus voltage of the DC bus to operate at a variable DC bus voltage setpoint. The control system can adjust the DC bus voltage setpoint based at least in part on the DC bus voltage and the output AC current of the inverter.

Abstract: A method of assembling an electrical machine includes programming at least one processor with a stator flux vector estimation scheme. The electrical machine has a stator at least partially extending around a rotor. The electrical machine is electrically coupled to an electric power system. The electric power system transmits at least one phase of electric power to and from the electrical machine with at least partial power conversion. The stator flux vector estimation scheme is programmed to generate at least one stator back-electromagnetic force (back-EMF) signal and to generate at least one stator flux vector signal using the at least one stator back-EMF signal. The at least one stator flux vector signal at least partially represents an estimated rotor position. The method also includes coupling at least one output device in data communication with the at least one processor.