Abstract:
A cooling assembly is disclosed having a device chamber, a cooling chamber, a heat exchanger, a fan and a controller, the heat exchanger having a first heat exchanger unit and a second heat exchanger unit located above the first heat exchanger unit. The fan includes a first fan adapted to generate a first cooling air flow. The cooling assembly further includes a first dust tray located between the first heat exchanger unit and the second heat exchanger unit, the first cooling air flow being directed towards the first dust tray, the first dust tray being adapted to receive and retain at least part of contaminant particles present in the first cooling air flow, the device chamber being separated from the cooling chamber.
Abstract:
A device validates reachability of nodes of a communication network of an industrial automation and control system. The device includes a collector module configured to update a data set including discovered dataflow information by detecting direct neighbour nodes having a physical connection to a selected node, and updating the data set by adding the selected node and those direct neighbour nodes which have configured logical network constraints matching logical network constraints of the selected node. The device includes a repeater module configured to repeat the selecting of a direct neighbour node in the data set and directing the collector module to update the data set using the selected direct neighbour node. The device includes a validation module configured to validate reachability of nodes of the network by comparing the data set with a data set including designed dataflow information which defines reachability requirements for nodes of the communication network.
Abstract:
Exemplary embodiments are directed to a gate drive circuit and a method for controlling a gate-controlled component. The gate drive circuit includes a PI controller that receives an input reference signal (vref,d/dt) controls a gate voltage of the gate-controlled component. The gate drive circuit also includes a first feedback loop for the PI controller adapted to provide feedback from a time derivative of a collector-to-emitter voltage (vCE) of the controlled component. The first feedback loop has a first gain (kv). A second is provided in the gate drive circuit feedback loop for the PI controller that provides feedback from the time derivative of the collector current (iC) of the controlled component. The second feedback loop has second gain (ki) and includes a clipping circuit that modifies the feedback signal in the second feedback loop during turn-on of the controlled component when the time derivative of the collector current is negative.
Abstract:
A system and method are provided for monitoring in real time the operating state of an IGBT device, to determine a junction temperature and/or the remaining lifetime of an IGBT device. The system includes a differential unit configured to receive a gate-emitter voltage characteristic of the IGBT device to be measured and to differentiate the gate-emitter voltage characteristic to obtain pulses correlating with edges formed by a Miller plateau phase during a switch-off phase of the IGBT device. The system also includes a timer unit configured to measure the time delay between the obtained pulses indicating the start and end of the Miller plateau phase during the switch-off phase of the IGBT device, and a junction temperature calculation unit configured to determine at least one of the junction temperature of the IGBT device and/or the remaining lifetime of the IGBT device based on the measured time delay.
Abstract:
A system and method are disclosed for controlling electrical machines including a controller component which receives a first signal providing a measured parameter of the electrical machine and a second signal providing a reference parameter of the electrical machine, using the first and second signals being used to produce a first control signal. A first filter component receives the first signal from the electrical machine and uses the first signal to produce a second control signal. A second filter component receives a third signal which relates to a reference parameter of a second electrical machine and uses the third signal to produce a third control signal. The system and second control signals are used to produce a first output control signal for provision to the first electrical machine, and the first and third control signals are used produce a second output control signal for provision to the second electrical machine.
Abstract:
A method and arrangement for detecting a frequency of a measured three-phase voltage. The method includes measuring a three-phase voltage, forming a discrete model for a periodic signal, the discrete model including the three-phase voltage and a difference between positive and negative voltage components of the three-phase voltage, forming a discrete detector based on the discrete model, detecting a fundamental wave component of the voltage and the difference between the positive and negative voltage components of the three-phase voltage from an error between the measured voltage and detected fundamental wave component of the voltage by using the discrete detector and a sampling time together with a detected frequency of the measured voltage. The detected frequency is detected from a detected difference between positive and negative voltage components of the measured voltage and from an error between the measured voltage and the detected fundamental wave component of the voltage.
Abstract:
A voltage sensor includes an insulator with mutually insulated electrodes embedded therein. The electrodes are coaxial and cylindrical and overlap axially along part of their lengths. They are mutually staggered and control the surfaces of electric equipotential such that there is a substantially homogeneous electric field outside the insulator and a substantially homogeneous but higher field within a sensing cavity within the insulator. A field sensor is arranged within the sensing cavity to measure the field. This design allows for the production of compact voltage sensors for high voltage applications.
Abstract:
In a method, computer program and apparatus for determining parameters of an equivalent circuit representing a transmission section of an electrical network, the transmission section (4) is representable as having at least two interfaces (5,6,7) with other sections (1,2,3) of the network, and the method comprises the steps of a) determining, for each of the interfaces (5,6,7), a voltage phasor ({overscore (v)}1,{overscore (v)}2,{overscore (v)}3) at the interface (5,6,7) and a phasor of a current ({overscore (i)}1,{overscore (i)}2,{overscore (i)}3) flowing through the interface (5,6,7), the measurements at the different interfaces (5,6,7) being made essentially simultaneously, and b) computing, from said voltage ({overscore (v)}1,{overscore (v)}2,{overscore (v)}3) and current ({overscore (i)}1, {overscore (i)}2,{overscore (i)}3)phasors, values of impedances ({overscore (Z)}T,{overscore (Z)}sh) constituting the equivalent circuit. This allows determining the equivalent circuit from a single set of essentially simultaneous measurements.
Abstract:
The invention is concerned with a resistive fault current limiter (FCL) based on thin superconducting films. The FCL comprises constrictions (2) with a reduced critical current, separated by connecting paths (3). Upon occurrence of a fault current, the former turn resistive simultaneously and build up a resistance which allows the applied voltage to drop entirely only over the constrictions. Only at a later stage, the connecting paths become resistive and dissipate energy. The thickness and width of an electrical bypass determine said normal resistivities of the constrictions and the connecting paths.
Abstract:
The curable casting compound comprises an epoxy resin having at least one aminoglycidyl group in the molecule, a curative, and a fluorosurfactant. In the manufacture of products based on this casting compound, the shaping and curing operation can be shortened considerably.