Abstract: A gradient amplifier for driving a gradient coil is disclosed. The gradient amplifier includes a direct current (DC) bus for receiving DC voltage generated from a series resonant converter, an inverter coupled to the DC bus configured to receive the DC voltage at the DC bus and convert the DC voltage to generate an output voltage to be applied to the gradient coil, and an inverter controller coupled to the inverter. The inverter controller is configured to generate control signals to control operation of the inverter based at least on a DC voltage feedback signal measured at the DC bus, an output voltage feedback signal measured at the output of the inverter, and a reference output voltage signal indicative of a desired voltage to be achieved at the output of the inverter.

Abstract: A power conversion system is disclosed including a DC bus for receiving DC power, a power converter for converting the DC power to AC power, and a controller. The controller includes an active power regulator for generating a phase angle command signal, a reactive power regulator for generating a voltage magnitude command, and an active power (P) and reactive power (Q) decoupling unit for decoupling interaction between the active and reactive power regulators. The PQ decoupling unit includes an active power compensation element and a reactive power compensation element. The active power compensation element is used for generating a phase angle compensation signal based on a reactive power error signal, to compensate the phase angle command signal. The reactive power compensation element is used for generating a voltage magnitude compensation signal based on an active power error signal, to compensate the voltage magnitude command signal.

Abstract: A method for regulating a power line voltage includes determining a slow voltage variation by filtering an actual voltage at terminals of the voltage regulation apparatus. A fast active power variation is determined by filtering a measured active power of the DG system; wherein a first frequency of the slow voltage variation is smaller than a second frequency of the fast active power variation. The voltage regulation apparatus settings are controlled based on the slow voltage variation and a reactive power output of the DG system is controlled based on fast active power variation.

Abstract: A power conversion system is presented. The system includes a power source coupled to a power converter and a controller. The controller is configured to determine a value of at least one parameter corresponding to the power source. Additionally, the controller is configured to provide a first portion of the at least one parameter to the power converter and modify an operating frequency of the power converter, duty ratio of the power converter, or a combination thereof. Furthermore, the controller is configured to obtain an electrical quantity at an output of the power converter based on the modified operating frequency, the modified duty ratio, or a combination thereof. Also, the controller is configured to deliver a combination of the electrical quantity obtained at the output of the power converter and a second portion of the at least one parameter to a load. Method for converting power is also presented.

Abstract: An exemplary power conversion system comprises an MPPT unit, a DC bus, a power converter, and a converter controller. The MPPT unit receives a feedback current signal and a feedback voltage signal from a power source and generates an MPPT reference signal based at least in part on the feedback current and voltage signals. The DC bus receives DC power from the power source. The power converter converts the DC power on the DC bus to AC power. The converter controller receives the MPPT reference signal from the MPPT unit and an output power feedback signal measured at an output of the power converter; generates control signals for AC power regulation and maximum power extraction based at least in part on the MPPT reference signal and the output power feedback signal; and sends the control signals to the power converter.

Abstract: A power conversion system is disclosed including a DC bus for receiving DC power, a power converter for converting the DC power to AC power, and a controller. The controller includes an active power regulator for generating a phase angle command signal, a reactive power regulator for generating a voltage magnitude command, and an active power (P) and reactive power (Q) decoupling unit for decoupling interaction between the active and reactive power regulators. The PQ decoupling unit includes an active power compensation element and a reactive power compensation element. The active power compensation element is used for generating a phase angle compensation signal based on a reactive power error signal, to compensate the phase angle command signal. The reactive power compensation element is used for generating a voltage magnitude compensation signal based on an active power error signal, to compensate the voltage magnitude command signal.

Abstract: An exemplary power conversion system is disclosed including a DC bus for receiving DC power; a line side converter electrically coupled to the DC bus for converting the DC power to AC power; and a voltage source controller to provide control signals to enable the line side converter to regulate the AC power. The voltage source controller comprises a signal generator to generate the control signals based at least in part on a power command signal and a power feedback signal. The voltage source controller further comprises a current limiter to, during a transient event, limit the control signals based at least in part on an electrical current threshold. The voltage source controller further comprises a voltage limiter to, during the transient event, limit the control signals based at least in part on a DC bus voltage feedback signal and a DC boundary voltage threshold.

Abstract: A method for regulating a power line voltage includes determining a slow voltage variation by filtering an actual voltage at terminals of the voltage regulation apparatus. A fast active power variation is determined by filtering a measured active power of the DG system; wherein a first frequency of the slow voltage variation is smaller than a second frequency of the fast active power variation. The voltage regulation apparatus settings are controlled based on the slow voltage variation and a reactive power output of the DG system is controlled based on fast active power variation.

Abstract: Embodiments of the invention relate to a power system for converting direct current (“DC”) power on a DC bus into alternating current (“AC”) power with a regulated voltage output and for feeding the AC power to an electrical system which may include a power utility or an electric grid, for example. A power conversion control system is used for controlling the power conversion and for maintaining the DC bus voltage (“DC voltage”) at a certain level.

Abstract: A power plant for providing alternating current (AC) power to an electrical grid is described. The power plant includes a first power converter couplable to the electrical grid at a first point of interconnection for receiving power from a first power source. The power plant also includes a second power converter couplable to the electrical grid at the first point of interconnection for receiving power from a second power source. The power plant also includes at least one sensor for measuring a voltage level at the first point of interconnection and a central controller for coordinating operation of the first power converter and the second power converter to determine an impedance of the electrical grid.

Abstract: An exemplary power conversion system is disclosed including a DC bus for receiving DC power; a line side converter electrically coupled to the DC bus for converting the DC power to AC power; and a voltage source controller to provide control signals to enable the line side converter to regulate the AC power. The voltage source controller comprises a signal generator to generate the control signals based at least in part on a power command signal and a power feedback signal. The voltage source controller further comprises a current limiter to, during a transient event, limit the control signals based at least in part on an electrical current threshold. The voltage source controller further comprises a voltage limiter to, during the transient event, limit the control signals based at least in part on a DC bus voltage feedback signal and a DC boundary voltage threshold.

Abstract: An exemplary power conversion system comprises an MPPT unit, a DC bus, a power converter, and a converter controller. The MPPT unit receives a feedback current signal and a feedback voltage signal from a power source and generates an MPPT reference signal based at least in part on the feedback current and voltage signals. The DC bus receives DC power from the power source. The power converter converts the DC power on the DC bus to AC power. The converter controller receives the MPPT reference signal from the MPPT unit and an output power feedback signal measured at an output of the power converter; generates control signals for AC power regulation and maximum power extraction based at least in part on the MPPT reference signal and the output power feedback signal; and sends the control signals to the power converter.

Abstract: Embodiments of the invention relate to a power system for converting direct current (“DC”) power on a DC bus into alternating current (“AC”) power with a regulated voltage output and for feeding the AC power to an electrical system which may include a power utility or an electric grid, for example. A power conversion control system is used for controlling the power conversion and for maintaining the DC bus voltage (“DC voltage”) at a certain level.