99results about How to "Reduce AC loss" patented technology

A high-Q human-portable, battery-powered self-correcting tunable resonator in a transmitter apparatus for inducing alternating currents of high quality in buried conductors to facilitate their location. The transmitter apparatus employs an FET-driven capacitive tuning circuit and a coil design that achieves high precision, high-quality transmission signals, and which is equipped with a high-voltage booster for facilitating fault-localization applications.

An oxide superconductor article having an oxide superconductor layer of a predetermined pattern is prepared by continuously advancing a wire having a textured surface into a deposition zone, dispensing droplets of a precursor solution to an oxide superconductor from a reservoir and the depositing droplets onto the textured surface of the wire that is introduced into the deposition zone, heating the wire or tape in the reaction zone under conditions to convert the precursor solution into an oxide superconductor; and collecting the wire after heating.

The invention discloses a DC bus distributed MPPT photovoltaic power generation system. The system comprises a photovoltaic cell array, a DC conflux boosting unit, a grid-connected inverter unit and an AC boosting unit, wherein the photovoltaic cell array, the DC conflux boosting unit, the grid-connected inverter unit and the AC boosting unit are connected in sequence; the photovoltaic cell array is composed of one or more cell arrays; the DC conflux boosting unit is composed of one or more DC power sources, and the intelligent DC power sources are used for boosting variable photovoltaic cell voltages sent by the photovoltaic cell array into stable high voltages; the grid-connected inverter unit comprises an inverter and is used for stabilizing output voltages of the DC conflux boosting unit and being responsible for start and stop of the working logic of the whole system; the AC boosting unit comprises a transformer. The DC bus distributed MPPT photovoltaic power generation system has the advantages of being simple in structure, low in cost, capable of improving the overall efficiency and the like.

The invention discloses a method for manufacturing an NbTi-CuNi-Cu superconductive composite wire rod. The method comprises the following steps of putting an NbTi alloy rod into a Cu tube, and obtaining an NbTi-Cu single-core composite rod blank through a hot extrusion or sleeve extension method; extending the NbTi-Cu single-core composite rod blank to a hexagonal rod to obtain an NbTi-Cu single-core composite rod, putting the NbTi-Cu single-core composite rod into a copper tube to manufacture an NbTi-Cu multi-core composite rod; putting the NbTi-Cu single-core composite rod or the NbTi-Cu multi-core composite rod into a copper tube, sleeving a CuNi tube with the copper tube, sleeving another copper tube with the CuNi tube, and sealing two ends of the copper tube; reducing space in the copper tube through a hot isostatic pressure method and performing hot extrusion to obtain an NbTi-CuNi-Cu composite rod; performing multiple cold extension and aging treatment on the NbTi-CuNi-Cu composite rod to obtain the superconductive composite wire rod with the required dimension and shape. By means of the method, alternating current loss of the NbTi superconductive composite wire rod is reduced, production processes are simplified, and production cost is reduced.

The invention discloses a preparation method of a high-temperature superconducting line. A plurality of strips are stacked together and welded into the high-temperature superconducting line in a hot dip coating manner. The preparation method particularly comprises the following steps: fixing each strip on a pay-off device and positioning center lines of the strips; conveying each strip into a solder furnace by a method of loading unreeled strips in unreeling spools; and positioning all strips in the solder furnace through idler wheels, welding and merging the strips into a line and drawing a charge to obtain the high-temperature superconducting line. The prepared high-temperature superconducting line is round or square, is high in critical current and suitable for bending and twisting, has relatively high physical strength and is not easily damaged; an external magnetic field sensed by a superconductor can be reduced; the critical current attenuation and the AC loss can be reduced; and the prepared high-temperature superconducting line has obvious advantages when applied to large superconducting power equipment.

The invention discloses a high-temperature superconducting twisted wire winding method. The winding method is characterized by comprising a step of strip cutting, wherein a high-temperature superconducting strip is cut into wire-shaped superconducting thin belts in a length direction; and a step of strip weaving, wherein the superconducting thin belts are weaved to form a new superconducting wire. According to the high-temperature superconducting twisted wire winding method, the macroscopic geometric structure of the superconducting strip is changed; the critical current of a superconducting magnet is improved in the application of the superconducting magnet; the alternating current loss is lowered, and the performance of the superconducting magnet is dramatically improved; and under the same condition, the cost for a user is equivalently reduced.

The invention discloses a planar transformer. The planar transformer comprises an upper magnetic core, a lower magnetic core and multiple flat coils arranged between the upper magnetic core and the lower magnetic core. The adjacent flat coils are insulated. Each flat coil is formed by multiple turns of metal conductors coiled into a spiral shape. The flat coils are vertically projected in space and overlapped vertically. Some flat coils form primary windings of the planar transformer, and the other flat coils form secondary windings of the planar transformer. The planar transformer is characterized in that according to the direction from the center to the outer side of each flat coil, the widths of the turns of each flat coil change as the following form: W1:W2:...:Wn=1:a:...:a(n-1), W represents the widths of the coils, n represents the number of turns of the coils and is larger than or equal to 1, a is larger than or equal to 0.5 and smaller than 1 or a is larger than 1 and smaller than or equal to 1.5, and the widths of the turns of each flat coil change consistently. Magnetic field distribution of the transformer can be changed by changing the widths of the turns of each coil, so that coupling performance and the alternating current loss are changed. The planer transformer has the advantage that leakage inductance and alternating current resistance of the planer transformer can be adjusted according to the actual needs.

The invention relates to a hybrid type flux coupling superconduction fault current limiter and current limitation method. According to the hybrid type flux coupling superconduction fault current limiter, a primary side winding coil of a coupling transformer and a high-speed switch are connected and are connected into an MOA zinc oxide resistor disc, a secondary side winding coil is connected with a superconduction current limiting material in series, and then the primary side winding coil and the secondary primary side winding coil are connected in an anti-parallel mode and then are connected into a main loop of a power system. When the power system operates normally, the high-speed switch is switched on; when the power system short-circuits, the high-speed switch is controlled to be triggered and switched off, the flux locking characteristic of the coupling transformer is relieved, the superconduction material is switched to be at the high resistance state as the through-flow of the superconduction material is larger than a set critical current, and at the moment, the current limiter carries out fault current limitation in an inductance-resistance hybrid mode. The hybrid type flux coupling superconduction fault current limiter is simple in structure and rapid in response, exchange losses generated when the superconduction current limiting material operates normally are reduced, and system economical efficiency of current limiting equipment is improved.

The dual-way multi-level soft switch DC/DC for superconductance energy-storage comprises a voltage unit with voltage level being increased by adding primary winding and number of H-bridge inverter and current level being increased by paralleling with dc output end of H-bridge inverter, a transformer unit, and a current unit with current/voltage level being increased by paralleling/series connected with its dc output respectively. This invention reduces current ripple and requirement to circuit, and lets system work flexible within charge and discharge state.

A low AC loss electrical conductor includes a plurality of single-filament superconducting strands longitudinally wound about one another. An insulative housing surrounds the plurality of single-filament superconducting strands.

A low AC loss electrical conductor includes an electrically conductive core surrounded by a first layer of superconductor filaments. A resistive shell surrounds the first layer and an insulation coating radially encloses the resistive shell.

The present invention relates to conductor for high voltage winding, and is especially one kind of cable with processed conducting wire core specially for winding. The twisted multi-core conductor is treated chemically, that is, the twisted multi-core conductor is soaked in low viscosity mixed solution containing sodium chlorite in 1-10 wt% and sodium hydroxide in 1-10 wt% to form thin insulating layer on the surface of each core conductor for mutual insulation. The formed copper oxide film will not be damaged in the subsequent twisting, pressing, drawing and other steps. The cable may be used in strong magnetic field and has the features of lowered AC loss, lowered eddy loss, saving in energy and high efficiency.

Losses are reduced in electrical conductors and filters, especially those made with superconducting cables or inductors, which carry currents having both direct current (DC) and alternating current (AC) portions as in rectifier busses and power distribution systems. Superconducting cables and chokes are capable of passing direct current with practically zero losses, but they exhibit considerable AC losses. A low impedance AC bypass of the superconducting cables and chokes minimizes these losses.

The invention belongs to the technical field of magnetic materials, in particular relates to a preparation method of MnZn ferrite in a magnetic field. The method comprises the following steps: by using a phase conversion method, placing a certain amount of mixed solution of Fe, Mn and Zn metal ions in a 0-6T magnetic field; under the stirring of nitrogen at the speed of 160-260ml/min, controlling the pH value to 9-10, heating to 95 DEG C, and insulating for 3-5 hours; then filtering, washing, and drying at the temperature of 70-90 DGE C, so as to obtain nano crystal MnZn ferrite powder, wherein the obtained powder is a single-phase MnZn ferrite particle and is of a typical spinel structure, the grain size is about 7-11 nanometers, and super paramagnetism is shown within a 40-300K temperature range. The obtained MnZn ferrite material has the advantages that magnetic conductivity is large, frequency characteristic is good, saturation induction density is greatly improved on the original basis, and obstruction temperature is greatly reduced.

The invention discloses a superconductor critical current and shunt temperature test device comprising a back field magnet, a temperature-variable sample dewar, a superconducting transformer, a cryogenic system, and a quenching detection and quenching protection system. The cryogenic system comprises a cryogenic refrigerator, a liquid helium storage tank, a superconducting transformer dewar, a back field magnet dewar, and a cryogenic transmission pipeline. The superconductor critical current and shunt temperature test device of the invention is applicable to superconductor critical current and shunt temperature test in a high back field. The maximum test back field is 10T, and the maximum test current is up to 50kA. The superconductor critical current and shunt temperature test device of the invention has the advantages of high test precision, low test cost, convenience of sample replacement, short test cycle, and the like.