Patent application number | Description | Published |
20110228578 | NON-ISOLATED DC-DC CONVERTER FOR SOLAR POWER PLANT - An exemplary non-isolated DC-DC converter for a solar power plant, can be adapted to connect to a full-bridge inverter. The converter includes positive and negative input terminals, and positive and negative output terminals. A plurality of switches, diodes, inductors and capacitors are connected in a circuit configuration to the input and output terminals. A control means is connected to the circuit for controlling the switching of a first, second, and third switch between an open and closed state. | 09-22-2011 |
20120242152 | METHOD FOR SEARCHING GLOBAL MAXIMUM POWER POINT - An exemplary method is disclosed for searching a global maximum power point in an arrangement comprising a series connection of photovoltaic power sources. The method can include determining a value of a reference by adding an increment to a previous value of the reference, wherein the value of the increment is determined on the basis of the power produced by the power sources. | 09-27-2012 |
20130114302 | METHOD AND APPARATUS FOR DETECTING ISLANDING CONDITIONS OF A DISTRIBUTED GRID - An exemplary method and apparatus for detecting islanding conditions of a distributed grid are disclosed, wherein transfer of power through a power electrical unit is controlled on the basis of a control reference. The apparatus includes a first stage and a second stage performing a respective portion of the method. The first stage injects a reactive component to the control reference, and, for at least one electrical quantity of the grid, determines a change in the quantity induced by the injected component, and determines, on the basis of the change in the electrical quantity, whether to move to the second stage of the method. The second stage, for at least one electrical quantity of the grid, determines a value of the electrical quantity, forms a positive feedback term using at the determined value adding a positive feedback term to the control reference, determines a change in an electrical quantity induced by the feedback term, and determines islanding condition on the basis of the change in the quantity induced by the feedback term. | 05-09-2013 |
20130200715 | CONVERTER ASSEMBLY AND A POWER PLANT INCLUDING THE CONVERTER ASSEMBLY - A converter assembly includes a DC-DC converter, an inverter, a DC link, an input capacitor, an inductor and a neutral conductor. The DC-DC converter includes at least one DC-DC converter unit. The input capacitor includes an input capacitor unit for each of the at least one DC-DC converter unit, where each of the input capacitor units has a midpoint. The neutral conductor is connected to a neutral point on an output side of the inverter. The inductor includes an inverter side inductor between each output terminal of the inverter means and the neutral point on output side of the inverter. The neutral conductor is connected to the midpoint of each of the input capacitor units. | 08-08-2013 |
20130229839 | METHOD AND APPARATUS FOR CONTROLLING A GRID-CONNECTED CONVERTER - A method and an apparatus for controlling a grid-connected converter which includes a boost converter, a buck converter, and a current source inverter having an output CL filter. An input of the buck converter input is connected to an output of the boost converter, and an input of the current source inverter is connected to an output of the buck converter. The method includes controlling a boost converter input voltage, controlling a boost converter output voltage through control of a buck converter output voltage, and controlling the current source inverter to produce an AC current from the buck converter output voltage. The apparatus implements the method. | 09-05-2013 |
20130329471 | METHOD AND APPARATUS FOR ZERO-SEQUENCE DAMPING AND VOLTAGE BALANCING - An exemplary method and an apparatus implementing the method for an arrangement having a three-phase, multi-level inverter, an output LCL-filter connecting the inverter to a grid, and a virtual-ground connection between the LCL-filter and the neutral point of the DC-link. The method includes determining a zero-sequence component of an LCL-filter inverter-side current, calculating a zero-sequence damping and balancing voltage term based on the LCL-filter inverter-side current zero-sequence component and voltages over the two halves of the DC-link, and adding the zero-sequence damping and voltage balancing term to the output voltage reference. | 12-12-2013 |
20140043014 | PHASE-LOCKED LOOP - A phase-locked loop and method for estimating a phase angle of a three-phase reference signal is disclosed, which includes an adaptive quadrature signal generator configured to calculate an estimated first state and an estimated second state of a model of an unbalanced three-phase system at a fundamental frequency of the reference signal on a basis of the reference signal and an estimated fundamental frequency; a reference frame transformation block configured to calculate a direct component and a quadrature component in a rotating reference frame synchronous with an estimated phase angle on a basis of the fundamental positive sequence component and the estimated phase angle, and configured to determine an estimate of an amplitude of the fundamental positive sequence component on the basis of the direct component; and an estimator configured to determine estimates of the estimated fundamental frequency and the estimated phase angle on the basis of the quadrature component. | 02-13-2014 |
20140241016 | METHOD AND APPARATUS FOR PRODUCING THREE-PHASE CURRENT - Exemplary embodiments are directed to methods and systems for producing a three-phase current to a three-phase output. Switching converters are used to generate a positive current, a negative current, and an intermediate current. The system is configured such that the produced positive current follows a path of a highest phase of a sinusoidal three-phase signal at a given time, the produced negative current follows a path of a lowest phase of the three-phase signal at the given time, and the produced intermediate current follows a path of a phase of the three-phase signal between the highest and the lowest phase at the given time. The produced currents are switched to each phase conductor of the three-phase output in sequence so that phase currents of the three-phase current are formed in the output conductors. | 08-28-2014 |
20140313627 | ACTIVE SNUBBER TOPOLOGY - Exemplary embodiments are directed to an snubber circuit and a power converter having an active circuit. The snubber circuit includes a series connection of a first diode and a first inductor connected between a first interfacing point and a first connection point, a second diode connected between a second connection point and a second interfacing point, a series connection of a third diode and a second inductor between a third interfacing point and the second connection point, a switching device connected between the first connection point and the third interfacing point, and a first capacitor connected between the first connection point and the second connection point. The first, the second, and the third diode are forward-biased along a path between the first interfacing point and the second interfacing point and through the third interfacing point. | 10-23-2014 |