Patent classifications
Y02E10/76
Use of distributed generator (DG) inverters as STATCOMs for decreasing line losses
The invention provides systems, methods, and devices relating to the provision of system-wide coordinated control voltage regulation support in power transmission and distribution networks using multiple inverter based power generation or absorption facilities, which are coupled to the power transmission and distribution networks for minimizing transmission and distribution line losses and for performing Conservation Voltage Reduction. The invention uses a novel control method of inverter based Distributed Generators as Static Synchronous Compensator (STATCOM) in a way that provides a dynamic voltage regulation/control with the inverter capacity remaining after real power generation or absorption, thereby decreasing system line losses and performing Conservation Voltage Reduction.
Hybrid power generation system combines renewable energy with direct-air-capture (DAC)
A method, system and computer-readable medium where an integrator application identifies an excess energy condition based on a supply load of electricity exceeding a consumptive load. The integrator application directs an air scrubber to utilize the excess electricity to remove carbon dioxide from the ambient air and routes the carbon dioxide to an enhanced coal bed methane well where methane is displaced by the carbon dioxide. In response to identifying an energy deficient condition based on the consumptive load exceeding the supply load, the integrator application routes the methane to a gas power plant and directs the gas power plant to convent the methane to electricity.
Magnetically immune gatedriver circuit
A gatedriver circuit for controlling a power electronic switch. The circuit provides a galvanic separation and is magnetically immune. The gatedriver circuit comprises a transformer arranged with two separate cores of magnetically conductive material each forming a closed loop. A first electrical conductor has windings around a part of both cores, and a second electrical conductor also has windings around part of both cores. The two cores are positioned close to each other to allow mutual magnetic interaction. The windings of the first and second electrical conductors around the first core have the same winding direction, and the windings of the first and second electrical conductors around the second core have opposite winding direction of the windings of the first and second electrical conductors around the first core, so as to counteract electric influence induced by a common magnetic field through the closed loops of the first and second cores. Hereby, such gatedriver circuit is suitable for controlling power switches in environments with strong magnetic fields, e.g. inside a high power wind turbine.
METHOD FOR ANALYZING STABILITY OF PERMANENT MAGNET SYNCHRONOUS GENERATOR-BASED WIND TURBINES CONNECTED TO WEAK POWER GRID CONSIDERING INFLUENCE OF POWER CONTROL
Provided is a method for analyzing the stability of a PMSG-WT connected to a weak power grid considering the influence of power control. New energy power generation mostly uses a perturbation and observation (P&O) method for maximum power point tracking, and nonlinear discontinuous links therein make stability analysis difficult. The present application analyzes the stability of the PMSG-WT connected to the weak grid system based on a describing function method, and fully considers the nonlinear discontinuous links in the power loop, thus making the analysis result more accurate. At the same time, the describing function method is a method that can quantitatively calculate the frequency and amplitude of oscillation. The analysis method of the present application can provide a powerful and good reference for oscillation suppression and controller design.
Method and system for adaptively switching prediction strategies optimizing time-variant energy consumption of built environment
A computer-implemented method and system is provided. The system adaptively switches prediction strategies to optimize time-variant energy demand and consumption of built environments associated with renewable energy sources. The system analyzes a first, second, third, fourth and a fifth set of statistical data. The system derives of a set of prediction strategies for controlled and directional execution of analysis and evaluation of a set of predictions for optimum usage and operation of the plurality of energy consuming devices. The system monitors a set of factors corresponding to the set of prediction strategies and switches a prediction strategy from the set of derived prediction strategies. The system predicts a set of predictions for identification of a potential future time-variant energy demand and consumption and predicts a set of predictions. The system manipulates an operational state of the plurality of energy consuming devices and the plurality of energy storage and supply means.
Selecting switching times of wind turbine converters
Provided is a method of controlling wind turbine converters of wind turbines parallel connected at a point of common coupling, the method including: generating for each converter within a same length of a pulse width modulation period a pulse, wherein the pulses start for different converters at different pulse start phases, wherein pulse start phase differences of the pulse start phases between at least two of adjacent converters are unequal.
Method for feeding electrical power into an electrical supply network
A method for exchanging or feeding electric power into an electricity supply grid that has a grid frequency using a converter-controlled generator at a grid connection point is provided. The method includes feeding in electric power depending on a control function, where the electric power may comprise active and reactive power, and the control function controls the power depending on at least one state variable of the grid. It is possible to select between a normal control function and a support control function, different from the normal control function, as the control function. The normal control function is selected when it has been detected that the grid is operating stably and the support control function is selected when a grid problem, grid fault or an end of the grid fault has been detected. The support control function controls the fed-in power to counteract an oscillation in the grid.
Control of a wind turbine power generation system for optimising DC link voltage
This invention relates to a method of controlling at least one wind turbine of a plurality of wind turbines connected to an electrical grid at a predefined point in the electrical grid. The wind turbine comprises a DC link connecting a generator side converter to a line side converter, where the line side converter is controlled according to a modulation index requested by a power converter controller. The method comprises determining a harmonic frequency signal indicative of a harmonic frequency value at the predefined point in the electrical grid; determining a deviation between the harmonic frequency signal and a permissible harmonic frequency value; determining a permissible modulation index based on the deviation; comparing the permissible modulation index to the modulation index requested by the power converter controller; and, altering a DC link voltage set-point based on the comparison between the permissible modulation index and the requested modulation index.
PREMISES POWER USAGE MONITORING SYSTEM
A control system (300) allows recognized standard premise electrical outlets, for example NEMA, CEE and BS, among others to be remotely monitored and/or controlled, for example, to intelligently execute blackouts or brownouts or to otherwise remotely control electrical devices. The system (300) includes a number of smart receptacles (302) that communicate with a local controller (304), e.g., via power lines using the TCP/IP protocol. The local controller (304), in turn, communicates with a remote controller (308) via the internet.
Method for feeding electrical power into an electrical supply network
A method for feeding electrical power into an electrical, three-phase supply network by means of an inverter device, wherein the electrical supply network has a three-phase line voltage with a first, second and third line voltage phase, comprising the steps: feeding the electrical power during normal operation if a fault-free operation has been identified for the electrical supply network, wherein during normal operation a positive sequence voltage and optionally a negative sequence voltage is recorded from the line voltage and a reactive current is specified at least depending on the positive sequence voltage and optionally depending on the negative sequence voltage, and changing to a fault operation if a voltage change in the line voltage meets a predetermined fault criterion, in particular if the voltage change exceeds a predeterminable minimum amount of change or a minimum amount of change gradient, wherein during the fault operation, at least directly after the change, the reactive current is specified depending on a space vector voltage.