Abstract: A converter system comprises a DC to AC converter, a maximum power point tracking device, and an array-side control. The DC link converts DC from a photovoltaic array to AC for a grid. The maximum power point tracking device is coupled to the array. The array-side control, which is coupled to the DC to AC converter and the device, prevents overvoltage in the DC bus of the DC to AC converter using array voltage and current data from the device and DC bus voltage data from the DC to AC converter during a grid transient by adjusting a maximum power point of the array to increase array voltage.

Abstract: A phase-locked loop circuit comprises a phase error detector for receiving a multi-phase reference signal and a synchronized phase signal of the phase-locked-loop circuit, and for performing a rotational transformation to convert the multi-phase reference signal into two-phase quantities at a synchronous rotation d-q reference frame. A monotonic transfer module receives the two-phase quantities, and generates a monotonic phase error signal which is monotonic when a phase difference between the multi-phase reference signal and the synchronized phase signal ranges from ?180 degrees to 180 degrees. A regulator receives the monotonic phase error signal, and generates a synchronized rotation frequency. An integrator receives the synchronized rotation frequency, and generates the synchronized phase signal.

Abstract: A power distribution system comprises a power conversion module for performing power conversion between a DC voltage at a DC side and an AC power at an AC side, and a conversion control system. The AC side of the power conversion module is electrically coupled to a grid. The conversion control system includes a phase-locked-loop circuit for receiving a multi-phase reference signal of a grid voltage and for generating a synchronized signal, a regulator for receiving reference commands, a two-phase grid feedback signal, and the synchronized signal and for generating a control signal for the power conversion module, and a phase compensation circuit for receiving the synchronized signal and the multi-phase reference signal of the grid voltage, for obtaining a phase displacement signal, and for generating a phase compensation signal for compensating the reference commands or for compensating the synchronized signal when the phase displacement signal exceeds a threshold value.

Abstract: A phase-locked loop circuit comprises a phase error detector for receiving a multi-phase reference signal and a synchronized phase signal of the phase-locked-loop circuit, and for performing a rotational transformation to convert the multi-phase reference signal into two-phase quantities at a synchronous rotation d-q reference frame. A monotonic transfer module receives the two-phase quantities, and generates a monotonic phase error signal which is monotonic when a phase difference between the multi-phase reference signal and the synchronized phase signal ranges from ?180 degrees to 180 degrees. A regulator receives the monotonic phase error signal, and generates a synchronized rotation frequency. An integrator receives the synchronized rotation frequency, and generates the synchronized phase signal.

Abstract: A system for controlling torque ripple in a permanent magnet synchronous machine includes a power converter configured to be coupled to the permanent magnet synchronous machine and to receive converter control signals and a system controller coupled to the power converter. The system controller includes a fundamental current controller configured for providing fundamental voltage commands, a harmonic current controller configured for using harmonic current commands, current feedback signals from the permanent magnet machine, and fundamental current commands in combination with positive and negative sequence regulators to obtain harmonic voltage commands, and summation elements configured for adding the fundamental voltage commands and the harmonic voltage commands to obtain the converter control signals.

Abstract: A system and method for controlling cross current in an interleaved power converter system having a plurality of converter threads coupled in parallel includes collecting a feedback current from each thread and obtaining a normal current and a differential mode current for each thread, based on its respective feedback current. The normal current of each thread is regulated to a commanded thread normal current value via a respective normal current control loop based on d-q rotating frame parameters. A differential mode cross current of each thread is regulated to zero via a respective differential mode cross current control loop based on d-q rotating frame parameters; while a differential mode cross current DC offset of each thread is regulated to zero via a respective differential mode cross current control loop based on stationary frame parameters.

Abstract: A system for controlling torque ripple in a permanent magnet synchronous machine includes a power converter configured to be coupled to the permanent magnet synchronous machine and to receive converter control signals and a system controller coupled to the power converter. The system controller includes a fundamental current controller configured for providing fundamental voltage commands, a harmonic current controller configured for using harmonic current commands, current feedback signals from the permanent magnet machine, and fundamental current commands in combination with positive and negative sequence regulators to obtain harmonic voltage commands, and summation elements configured for adding the fundamental voltage commands and the harmonic voltage commands to obtain the converter control signals.

Abstract: A power generation system comprises at least two electrical systems connected at an electrical connection point. Each electrical system comprises a power conversion system comprising a converter including a plurality of switches for converting direct current power into alternating current power. The power generation system comprises a control system including at least two pulse width modulation (PWM) modulators, each PWM modulator for obtaining a fundamental waveform and a carrier signal, using the fundamental and carrier signals to generate a PWM pattern, and for providing the PWM pattern to a respective converter for driving the switches of the respective converter. The control system is configured to interleave carrier signals, fundamental waveforms, or a combination of carrier signals and fundamental waveforms of the at least two electrical systems to generate interleaved PWM patterns respectively for the at least two converters.

Abstract: A protective circuit for a multi-level converter including a DC link capacitor bank includes: an energy absorbing element; switches, wherein at least two of the switches each couple the energy absorbing element to the capacitor bank; and a controller configured to provide control signals to the switches to selectively actuate the switches to enable control of energy dissipation and to enable control of voltage balance on the capacitor bank of the multi-level converter.

Abstract: A system for controlling torque ripple in a permanent magnet synchronous machine includes a power converter configured to be coupled to the permanent magnet synchronous machine and to receive converter control signals and a system controller coupled to the power converter. The system controller includes a fundamental current controller configured for providing fundamental voltage commands, a harmonic current controller configured for using harmonic current commands, current feedback signals from the permanent magnet machine, and fundamental current commands in combination with positive and negative sequence regulators to obtain harmonic voltage commands, and summation elements configured for adding the fundamental voltage commands and the harmonic voltage commands to obtain the converter control signals.

Abstract: A system and method for controlling cross current in an interleaved power converter system having a plurality of converter threads coupled in parallel includes collecting a feedback current from each thread and obtaining a normal current and a differential mode current for each thread, based on its respective feedback current. The normal current of each thread is regulated to a commanded thread normal current value via a respective normal current control loop based on d-q rotating frame parameters. A differential mode cross current of each thread is regulated to zero via a respective differential mode cross current control loop based on d-q rotating frame parameters; while a differential mode cross current DC offset of each thread is regulated to zero via a respective differential mode cross current control loop based on stationary frame parameters.

Abstract: A protective circuit for a multi-level converter including a DC link capacitor bank includes: an energy absorbing element; switches, wherein at least two of the switches each couple the energy absorbing element to the capacitor bank; and a controller configured to provide control signals to the switches to selectively actuate the switches to enable control of energy dissipation and to enable control of voltage balance on the capacitor bank of the multi-level converter.

Abstract: A power system for providing an output power to a load is provided. The system comprises a generator configured to generate an alternating current input power and an power converter system coupled to the generator and configured to generate an output power and provide the output power to the load through at least one transformer. The system further comprises a converter control system coupled to the converter system and configured to drive the converter system in an interleaved pattern to reduce harmonic components in the output power and the alternating current input power.

Abstract: A power system for providing an output power to a load is provided. The system comprises a generator configured to generate an alternating current input power and an power converter system coupled to the generator and configured to generate an output power and provide the output power to the load through at least one transformer. The system further comprises a converter control system coupled to the converter system and configured to drive the converter system in an interleaved pattern to reduce harmonic components in the output power and the alternating current input power.