Abstract: A renewable power system is provided. The renewable power system includes a plurality of power generating devices and a plurality of power converters. Each power converter of the plurality of power converters is electrically coupled to at least one power generating device of the plurality of power generating devices and a load. The renewable power system further includes a plurality of controllers. Each of the plurality of controllers includes a processor coupled in communication with at least one power converter of the plurality of power converters. The processor is configured to detect a load power of the load, determine an available power of the plurality of power generating devices, and, in response to the load exceeding the available power of the plurality of power generating devices, adjust at least one parameter of the at least one power converter.

Abstract: A method for controlling a network of inverter-based resources (IBRs) during a disturbance includes, in response to a start of the disturbance, employing a system-level overload ride-through (SLORT) algorithm among the network of IBRs. The SLORT algorithm includes determining, via a SLORT control module, a modified parameter set for one or more of the IBRs using regularly-updated system-level analyses, transmitting, via the SLORT control module, the modified parameter set to the IBRs, and automatically activating, via one or more local controllers of the IBRs, the modified parameter set, wherein automatically activating the modified parameter set comprises rapidly re-parameterizing one or more parameters of the one or more of the IBRs for a duration of and for a time period after the disturbance so as to transition the network of IBRs from a pre-disturbance stable state to a post-disturbance stable state.

Abstract: A method for controlling a network of inverter-based resources connected to a power grid during a disturbance includes employing a distributed transient virtual impedance algorithm among the network of inverter-based resources (IBRs) after a start of or in anticipation of the disturbance. The distributed transient virtual impedance algorithm includes determining, via at least one of one or more power flow equations, one or more energy function equations, and one or more estimated power capabilities, a virtual impedance control parameter and a modified power reference for one or more of the IBRs.

Abstract: A method for controlling an inverter-based resource (IBR) connected to a power grid during a grid event includes operating the IBR based on a first virtual impedance reference prior to the grid event, the first virtual impedance reference being used for determining a first virtual impedance of the IBR defining a first virtual reactance and a first virtual resistance. The method also includes receiving an indication of a start of the grid event that causes a change in the first virtual impedance reference to a second virtual impedance reference. Immediately after the change in the first virtual impedance reference, the method includes activating a soft activation module for outputting a second virtual impedance defining a second virtual reactance and a second virtual resistance that maintains a magnitude of the second virtual impedance at or above a magnitude of the second virtual impedance reference so as to reduce current in the inverter-based resource.

Abstract: A method for operating an asynchronous doubly-fed wind turbine generator connected to a power grid in a grid-forming mode to emulate a virtual synchronous machine. The doubly-fed wind turbine generator includes a line-side converter coupled to a rotor-side converter via a direct current (DC) link. The method includes receiving, via a controller, at least one reference command from an external controller. The method also includes controlling rotor flux of the doubly-fed wind turbine generator using the at least one reference command. Further, the method includes providing power droop control for the doubly-fed wind turbine generator through at least one of rotor-side reference frame rotation and d-axis flux control.

Abstract: A method for operating an asynchronous doubly-fed wind turbine generator connected to a power grid in a grid-forming mode to emulate a virtual synchronous machine. The doubly-fed wind turbine generator includes a line-side converter coupled to a rotor-side converter via a direct current (DC) link. The method includes receiving, via a controller, at least one reference command from an external controller. The method also includes controlling rotor flux of the doubly-fed wind turbine generator using the at least one reference command. Further, the method includes providing power droop control for the doubly-fed wind turbine generator through at least one of rotor-side reference frame rotation and d-axis flux control.

Abstract: A virtual synchronous generator device disclosed. The device includes an inverter and inverter controller having a power control portion, a power reserve portion, a power point tracking control portion, and a virtual inertia control portion. The power reserve portion determines an amount of power to be reserved and sends a signal, indicative of the determined amount of power to the power point tracking controller. The power point tracking controller determines a power point that is less than a MPP, and provides a signal to the power control portion indicative of the determined power point. The inertia control portion determines a virtual inertia and provides a signal indicative of the virtual inertia to the power control portion. The power control portion provides a power control signal to the inverter based on the power point tracking signal and the inertia command signal.

Abstract: A virtual synchronous generator device disclosed. The device includes an inverter and inverter controller having a power control portion, a power reserve portion, a power point tracking control portion, and a virtual inertia control portion. The power reserve portion determines an amount of power to be reserved and sends a signal, indicative of the determined amount of power to the power point tracking controller. The power point tracking controller determines a power point that is less than a MPP, and provides a signal to the power control portion indicative of the determined power point. The inertia control portion determines a virtual inertia and provides a signal indicative of the virtual inertia to the power control portion. The power control portion provides a power control signal to the inverter based on the power point tracking signal and the inertia command signal.

Abstract: A solar power conversion system includes a photovoltaic array having photovoltaic modules for generating direct current (DC) power. A power converter is provided in the system for converting the DC power to alternating current (AC) power. A transformer is coupled between the power converter and a power grid for transmitting the AC power to the power grid. The transformer is connected to the power grid at the point of common coupling (PCC) and to the power converter at output terminals. A reactance estimation module is provided in the system for estimating a short circuit reactance at PCC based on a small change in a measured voltage at output terminals with respect to a small change in a measured reactive power at the output terminals. Further, a maximum reactive power estimation module estimates a maximum reactive power based on the estimated reactance, the measured voltage at output terminals, and the measured reactive power at the output terminals.

Abstract: A power converter including a detection apparatus and method for detecting an islanding condition based on measurements of one or more currents and voltages within the power converter provided to a current regulator to generate a signal that is provided in a positive feedback loop and is indicative of an islanding condition.

Abstract: Systems (100), power modules (108), and methods for using in controlling a converter (110) coupled between a power generator (104) and an electric grid (102). A power module (108) includes the converter (110) configured to supply the output from the power generator (104) to the electric grid (102) and a controller (112) coupled to the converter (110) and configured to disable the converter (110) in response to a grid fault event, to identify the type or the grid fault event after a first predetermined interval from disabling the converter (110), and to enable switching of the converter (110), when the type of the grid fault event is identified as a low voltage condition.

Abstract: A power generation system, apparatus and method to buffer power fluctuations are provided. At least one inverter (14) may be coupled to a photovoltaic power generator (10). The inverter may be subject to at least one operational constraint. A power-buffering circuitry (16) may be connected between the photovoltaic power generator and the inverter to buffer power generation fluctuations which can occur in power generated by the photovoltaic power generator, and satisfy the operational constraint of the inverter notwithstanding an occurrence of the power generation fluctuations. A controller (14) may be coupled to the power-buffering circuitry and may be responsive to the parameter of the photovoltaic power generator to perform at least one control action regarding the power fluctuations. Control actions may be performed by the controller independently of a control strategy of the inverter.

Abstract: A solar power conversion system includes a photovoltaic array having photovoltaic modules for generating direct current (DC) power. A power converter is provided in the system for converting the DC power to alternating current (AC) power. A transformer is coupled between the power converter and a power grid for transmitting the AC power to the power grid. The transformer is connected to the power grid at the point of common coupling (PCC) and to the power converter at output terminals. A reactance estimation module is provided in the system for estimating a short circuit reactance at PCC based on a small change in a measured voltage at output terminals with respect to a small change in a measured reactive power at the output terminals. Further, a maximum reactive power estimation module estimates a maximum reactive power based on the estimated reactance, the measured voltage at output terminals, and the measured reactive power at the output terminals.

Abstract: A power converter system includes a converter configured to be coupled to a power generation unit for receiving current from the power generation unit. A bus is coupled to the converter, and energy is stored within the bus when the current is conducted through the power converter system. A damping circuit is configured to be coupled to the bus and to the power generation unit, and a control system is coupled to the converter and to the damping circuit. The control system is configured to selectively discharge at least a portion of the energy stored within the bus through the damping circuit when the control system determines that a predetermined condition is met.

Abstract: A power converter system includes a converter configured to be coupled to a power generation unit for receiving current from the power generation unit. A bus is coupled to the converter, and energy is stored within the bus when the current is conducted through the power converter system. A damping circuit is configured to be coupled to the bus and to the power generation unit, and a control system is coupled to the converter and to the damping circuit. The control system is configured to selectively discharge at least a portion of the energy stored within the bus through the damping circuit when the control system determines that a predetermined condition is met.

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: Systems (100), power modules (108), and methods for using in controlling a converter (110) coupled between a power generator (104) and an electric grid (102). A power module (108) includes the converter (110) configured to supply the output from the power generator (104) to the electric grid (102) and a controller (112) coupled to the converter (110) and configured to disable the converter (110) in response to a grid fault event, to identify the type or the grid fault event after a first predetermined interval from disabling the converter (110), and to enable switching of the converter (110), when the type of the grid fault event is identified as a low voltage condition.

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 power generation system, apparatus and method to buffer power fluctuations are provided. At least one inverter (14) may be coupled to a photovoltaic power generator (10). The inverter may be subject to at least one operational constraint. A power-buffering circuitry (16) may be connected between the photovoltaic power generator and the inverter to buffer power generation fluctuations which can occur in power generated by the photovoltaic power generator, and satisfy the operational constraint of the inverter notwithstanding an occurrence of the power generation fluctuations. A controller (14) may be coupled to the power-buffering circuitry and may be responsive to the parameter of the photovoltaic power generator to perform at least one control action regarding the power fluctuations. Control actions may be performed by the controller independently of a control strategy of the inverter.

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.