Abstract: A memory device that accurately tracks memory operations includes a vertical loopback for tracking a sense clock signal to a row address decoder, and read and write reference bit lines in a reference column that include loopbacks for vertically tracking a selected bit line during read and write operations. Preferably the widths of word lines and a sense line are equal to enable the sense line to horizontally track any selected word line. The memory device also includes tri-state input/output (I/O) latches to latch sense amplifier outputs. A drive circuit of the tri-state I/O latch is disabled when the output is available at the corresponding sense amplifier and enabled when the output is latched by the latch circuit.

Abstract: A power dissipating arrangement for dissipating power from a generator in a wind turbine is provided. The generator comprises a plurality of output terminals corresponding to a multi-phase output. The power dissipating arrangement comprises a plurality of dissipating units, a plurality of semiconductor switches, a trigger circuit for switching the semiconductor switches and a control unit for controlling the operation of the trigger circuit, thereby controlling the switching of the semiconductor switches. Each dissipating unit includes a first terminal and a second terminal. The first terminal of each dissipating unit is coupled to each output terminal of the generator. Each semiconductor switch includes a first terminal anode, a second terminal and a gate terminal.

Abstract: A variable speed wind turbine is provided. The variable speed wind turbine comprises a generator, a power converter for converting at least a portion of electrical power generated by the generator, the power converter comprising a generator-side converter, a grid-side converter and a DC (direct current) link therebetween, a power dissipating unit operatively coupled to the DC-link, and a controller. The controller is adapted to receive a request to reduce power output from the wind turbine, determine a feed forward power signal based on a reference generator power and a desired turbine power, and operate the power dissipating unit based on the feed forward power signal.

Abstract: A system for detecting soft errors in a memory device includes a latch, a master flip-flop and a slave flip-flop. The latch receives input data (control and/or address signals) at the beginning of a memory operation in response to a rising edge of a first clock signal. The output of the latch is provided to the master flip-flop. The master flip-flop continuously receives and stores the latch output during the memory operation based on a second clock signal. The slave flip-flop receives and stores the output of the master flip-flop at the end of the memory operation based on the second clock signal. A comparator compares the input data with the output of the slave flip-flop to detect soft errors that occur during the memory operation.

Abstract: A method of segmenting an image into foreground and background regions, is disclosed. The image is divided into a plurality of blocks. The plurality of blocks comprises at least a first block of a first size and a second block of a second size. A first plurality of mode models of the first size for the first block and a second plurality of mode models of the second size for the second block are received. If foreground activity in the first block is higher than the foreground activity in the second block, the first size is smaller than the second size. The image is segmented into foreground and background regions based on the received mode models.

Abstract: A memory device that accurately tracks memory operations includes a vertical loopback for tracking a sense clock signal to a row address decoder, and read and write reference bit lines in a reference column that include loopbacks for vertically tracking a selected bit line during read and write operations. Preferably the widths of word lines and a sense line are equal to enable the sense line to horizontally track any selected word line. The memory device also includes tri-state input/output (I/O) latches to latch sense amplifier outputs. A drive circuit of the tri-state I/O latch is disabled when the output is available at the corresponding sense amplifier and enabled when the output is latched by the latch circuit.

Abstract: A wind turbine includes a grid side converter coupled to a grid via a power line. The method includes determining a first active power reference and a first reactive power reference indicating a requested amount of active power and reactive power, respectively, depending on at least a wind turbine operation strategy; determining a positive and negative sequence components of a grid voltage; determining indications of an actual amount of active power and reactive power to be supplied by the grid side converter to the grid, respectively; generating a parameters defining a proportion of positive sequence current component and negative sequence current component to be injected by the grid side converter in order to supply active power and reactive power; and supplying, with the grid side converter, active and reactive power to the power line based on the current reference.

Abstract: A controller arrangement of an electrical power transfer system (1) of a wind turbine is described. The wind turbine has an electrical generator and is connected to an electrical power grid, wherein the power transfer system (1) is arranged to transfer electrical power from the generator to the grid. The power transfer system (1) has at least two electrical elements (2-6), e.g. converters, and at least two controllers (15-17) each arranged to control at least one element (2-6).

Abstract: According to a method of the present invention, a method of operating a wind turbine comprising a power generator, a generator side converter connected to the power generator, a line side converter connected to a power grid through power components, and a DC-link connected between the generator side converter and the line side converter is provided, the method comprising: monitoring the grid voltages on the power grid for overvoltage events; if an overvoltage event is detected, operating the line side converter in an overmodulation range for at least a part of the duration of the overvoltage event.

Abstract: A power conversion system for converting electrical power from at least one power source includes a plurality of converter chains which couple the at least one power source to at least one load. At least two of the converter chains comprise an associated dissipating unit. The dissipating units are coupled via at least one switch. A controller is arranged to control the at least one switch to route power to be dissipated from one of the converter chains to the converter chain's associated dissipating unit, or to at least one of the other dissipating units, or to the converter chain's associated dissipating unit and to at least one of the other dissipating units, to cause corresponding dissipation of the power to be dissipated.

Abstract: According to an embodiment of the present invention, a method of operating a wind turbine including a power generator, a generator/machine side converter connected to the power generator, a grid/line side converter connected to a power grid through power components, and a DC-link connected between the machine side converter and the line side converter, comprises: Monitoring the power grid for overvoltage events; if an overvoltage event is detected disabling active operation of the machine side converter and of the line side converter, enabling an AC-load dump connected between the machine side converter and the power generator in order to dissipate active power output by the power generator into the AC-load dump, waiting for a waiting period, and enabling active operation of the line side converter and the machine side converter if the overvoltage ends within the waiting period.

Abstract: A system for detecting soft errors in a memory device includes a latch, a master flip-flop and a slave flip-flop. The latch receives input data (control and/or address signals) at the beginning of a memory operation in response to a rising edge of a first clock signal. The output of the latch is provided to the master flip-flop. The master flip-flop continuously receives and stores the latch output during the memory operation based on a second clock signal. The slave flip-flop receives and stores the output of the master flip-flop at the end of the memory operation based on the second clock signal. A comparator compares the input data with the output of the slave flip-flop to detect soft errors that occur during the memory operation.

Abstract: A system for a wind turbine generator comprising: a set of voltage limiting elements, and a controller configured to bypass the voltage limiting elements when a line voltage is below a predetermined threshold, and configured to connect each voltage limiting element in series between a grid side converter and a turbine transformer of the wind turbine generator, and to determine a current control reference signal for controlling the grid side converter (to generate a determined current) when the line voltage is above the predetermined threshold.

Abstract: Parameters of PM machines, especially for IPM machine, are known to vary by significant amounts. This affects the controllability of such machines, which may lead to reduced power loading capability and increased losses. The present invention relates to a method for PM machine inductance profile identification based on voltage mode stator flux observation which could be easily integrated to the generator start-up process in wind turbine application for both stator flux vector feedback control system and current vector feedback control system.

Abstract: According to an embodiment of the present invention, a method of controlling a grid side converter of a wind turbine is provided, wherein an output of the grid side converter is connected or connectable via a power line to an input of a grid transformer, the method comprising: determining a converter volt-sec occurring at the output of the grid side converter based on a converter voltage occurring at the output of the grid side converter; determining a volt-sec error between the determined converter volt-sec and a converter volt-sec reference, wherein the converter volt-sec reference is determined based on active power reference, reactive power reference, line current and a line voltage occurring at the input of the grid transformer (or at wind turbine terminals); and controlling, based on the determined volt-sec error, the grid side converter such that the volt-sec error is partly or fully compensated.

Abstract: A method for operating a power generation system coupled to a power grid during a grid unbalance event, a method for determining an injection current to be supplied into a power grid by a power generation system, and a method for addressing an asymmetric grid fault in a power grid connected to a power generation system are provided. The methods may be carried out based on a reactive or an active power/current priority.

Abstract: Disclosed herein are a method, system, and computer program product for aligning an input video frame from a video sequence with a background model associated with said video sequence. The background model includes a plurality of model blocks (820, 830), each one of the plurality of model blocks (820, 830) being associated with at least one mode (821, 822, 823, 831, 832, 833, 834), wherein each mode (821, 822, 823, 831, 832, 833, 834) includes a plurality of frequency domain attributes. The method selects, for each one of the plurality of model blocks, a reference mode dependent upon a mode of the corresponding model block, generates a background reference image (840) comprising the plurality of selected reference blocks (841, 842), and then aligns the input frame with the background model (810), based on the background reference image (810).

Abstract: According to an embodiment, a method of operating a wind turbine comprising a DC-to-AC voltage converter is provided, the wind turbine being connectable to a grid via the DC-to-AC voltage converter, the method comprising: determining a line voltage of a power line connecting the DC-to-AC voltage converter to the grid; if the determined line voltage exceeds a predefined voltage threshold value, injecting reactive current into the power line, wherein the amount of reactive current injected is chosen such that an output voltage of the DC-to-AC voltage converter is kept within a predetermined voltage range.

Abstract: Embodiments are directed to securing mixed-mode applications in a semi-trusted environment. In an embodiment, a computer system securely loads native data files associated with a mixed-mode application. The secure loading ensures that the native components upon which the managed component depends are authentic. The computer system implements a securely stored handle associated with the loaded native data files to provide secure communications between the managed component and the loaded native data files. The handle provides a trusted function pointer to an associated mixed-mode application function. The computer system also initiates a security permission request for each resource that is passed to the native components during execution of the mixed-mode application, so that each resource is verified before execution.

Abstract: A method and system for updating a visual element model of a scene model associated with a scene, the visual element model including a set of mode models for a visual element for a location of the scene. The method receives an incoming visual element of a frame of the image sequence and, for each mode model, classifies the respective mode model as either a matching mode model or a distant mode model, by comparing an appearance of the incoming visual element and a set of visual characteristics of the respective mode model. The method removes a distant mode model from the visual element model, based upon a first temporal characteristic of a matching mode model exceeding a maturity threshold and a second temporal characteristic of the distant mode model being below a stability threshold.