Abstract:
DC-DC converter systems are disclosed. DC-DC converter systems may include an input, an output, a resonant switched-capacitor DC-DC converter, and a second DC-DC converter. The resonant switched-capacitor DC-DC converter may include a first input side and a first output side. The second DC-DC converter may include a second input side and a second output side. The first input side may be connected to the input, the second input side may be connected to an input voltage, and the first and second output sides may be connected in series to the output. In some examples, the second DC-DC converter may be a buck-boost DC-DC converter.
Abstract:
In a method based on the MPDTC algorithm for controlling an inverter of an electrical system, the harmonics and resonances in the inverter can be damped by extracting frequency information from predicted data of the MPDTC algorithm and by damping harmonic distortion of the electrical system by reintroducing the extracted frequency information into a control loop of the inverter.
Abstract:
A wireless communication device providing a node in an industrial wireless network investigates if there is more than one data packet with process control data from the same data originating device destined for a process control device in a transmission queue, where the data originating device is an interface to the process being controlled and transmits data packets in the transmission queue. If there is more than one such data packet, the wireless communication device further compares time stamps of the data packets, where a time stamp reflects the time of generation of a corresponding data packet, keeps the newest data packet and discards older data packets, so that only the most recent data packets from a data originating device are sent to the process control device from the node.
Abstract:
A method of determining a fault direction parameter of a fault on an AC transmission line of a power distribution system relative to a measurement location of the transmission line. The method includes measuring a time-dependent AC current of the transmission line at the measurement location to obtain time-domain current data indicative of the measured current, obtaining a time of the fault on the transmission line, identifying first and second times by identifying a periodically re-occurring feature of the current data, such that the fault time is between the first and second times, extracting, from the current data, an offset indicative parameter indicative of a time offset of the current at the fault time and between the first and second times, calculating an offset direction parameter by comparing the offset indicative parameter to a non-offset indicative parameter, and establishing the fault direction parameter based on the offset direction parameter.
Abstract:
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.
Abstract:
Techniques are disclosed for performing the estimation and/or prediction of the dynamic system state of large power system networks, using a multi-processor approach. More particularly, a large power system network is divided into smaller sub-systems, each sub-system having associated dynamic state variables. Each sub-system is assigned to one or more of a plurality of processing elements, and dynamic state variables for each sub-system are estimated or predicted independently, using the processing elements and sensor measurements. In several embodiments, the dynamic state of each sub-system is computed through the construction of a set of dedicated observers, such as linear parameter-varying (LPV) observers, which are designed to reduce the effects of other sub-systems on the state estimation problem.
Abstract:
A transformer diagnosis apparatus and method which can advantageously be used for on-line diagnosis of a transformer, and by which transformer properties may be monitored and/or determined. The diagnosis method includes collecting, for at least two different transformer loads, measurements of a current being indicative of the transformer load, as well as measurements of at least one further transformer AC signal. The method further includes deriving, from the collected measurements, at least two values of a quantity which depends on a transformer property as well as on transformer load; and determining, from the derived values, a set of coefficient(s) of a relation for how the quantity is expected to vary with transformer load. The method further includes using the determined coefficient(s) in performing a diagnosis of the transformer.
Abstract:
An electrical insulation system includes a first insulation layer having a first polymer and a first filler in the form of nanoparticles, and a second insulation layer including a second polymer and a second filler in the form of either chromium oxide, Cr2O3, iron oxide, Fe2O3, or a mixture of chromium oxide and iron oxide. At least one of the insulation layers is in the form of a solid and flat sheet. An insulation system combining the first insulation layer with well dispersed nanoparticles and the second insulation layer filled with Cr2O3particles and/or Fe2O3 particles.
Abstract translation:电绝缘系统包括具有第一聚合物和纳米颗粒形式的第一填料的第一绝缘层,以及包含氧化铬,Cr 2 O 3,氧化铁,Fe 2 O 3形式的第二聚合物和第二填料的第二绝缘层 ,或氧化铬和氧化铁的混合物。 绝缘层中的至少一个是固体和平板的形式。 一种将第一绝缘层与良好分散的纳米颗粒结合的绝缘系统和填充有Cr 2 O 3颗粒和/或Fe 2 O 3颗粒的第二绝缘层。
Abstract:
A mold for molding a UV cured article in an inner volume thereof, the mold including a mold wall surrounding the inner volume, the mold including a UV-transparent polymer and UV radiation deflecting particles immersed in or adhered to a surface of the mold wall. Also provided is an apparatus including the mold and a process for molding a UV cured article.
Abstract:
A power line protection system and method are described with a current meter for monitoring the current in the protected power line and a circuit breaker, with the current meter including a sensor, particularly a fiber optic current sensor, for monitoring a direct current component in the current transmitted and an analyser for testing the direct current component and for generating a fault signal for the circuit breaker.