153 results about "Ampere-turn" patented technology

The invention discloses a multitooth magnetic bridge type hybrid excitation magnetic flux switching motor. Permanent magnets, an armature winding and a single-phase excitation winding are installed on a stator; the tooth number of the stator is four times of the number of the permanent magnets; and part of a rotor part is a salient pole, and a rotor has no winding or permanent magnets and has simple and firm structure. An air gap magnetic field comprises an electric excitation magnetic field generated by the excitation winding and a magnetic field generated by the permanent magnets and is adjusted by changing the magnitude and the direction of excitation current, thereby improving the rotating speed operating range and the magnetic weakening capability of the motor. An electric excitation magnetic force line is connected with a magnetic bridge for closing after penetrating through an iron core at the top of the permanent magnets, which is beneficial to reducing the electric excitation ampere turns. The invention has parallel connecting structure of the excitation winding and the permanent magnet in space, bipolarity of phase magnetic flux, large magnetic chain change amplitude value and higher torque output capability and power density and is suitable for a low-speed straight application occasion.

Provided are an all-fiber electronic current transformer frequency characteristic testing device and a testing method. The testing device comprises a control calculation and display unit, a frequency response control unit and an equal ampere-turn current raising device. The control calculation and display unit is used for generating reference data and control instructions to drive the frequency response control unit and receive test data from the frequency response control unit. The frequency control unit is used for variable alternating current signals with variable frequency and size variable currents; under the control of a synchronous clock, the frequency control unit collects digitalized output signals of a data interface of a current transformer, and the collected output signals of the tested current transformer are formatted and then are transmitted to the control calculation and display unit. The equal ampere-turn current raising device is used for further raising the variable alternating current signals through an equal ampere-turn method, and the variable alternating current signals are applied to the tested current transformer. According to the testing device, large-range frequency regulation can be carried out conveniently, signals are accurate and stable, and the requirements of the fiber current transformer which has the characteristics of being wide in frequency band and large in dynamic range and the requirement of quantity transmission are met.

An electromagnetic semi-conticasting method for casting Al-alloy tube features that its casting temp is 710-770 deg.C, its casting speed is 60-180 mm/min, its electromagnetic field is 10000-20000 ampere-turn and 1-100 Hz for internal coil and 2000-8000 ampere-turn and 1-100 Hz for external coil, and the phase difference between said two coils is 0-359 deg., Its apparatus is composed of semi-conticaster, internal and external crystallizers, two water-cooled coils, etc.

The invention discloses a design method for an open magnetic resonance superconducting magnet. The design method uses a method for searching a seed coil and comprises the following steps of: determining a solving region according to design parameters of the magnetic resonance superconducting magnet; searching from the solving region and calculating to obtain the quantity and the position of the seed coil according to set constraint conditions; then solving by using a regularization method to obtain ampere turns of the see coil; selecting work current density, determining the section of the seed coil and forming a structure of an initial coil; and with the initial coil as a main magnetic field coil, adding a shield coil and further optimizing to enable a magnetic filed generated by the magnetic resonance superconducting magnet to meet the requirements of the uniformity of the magnetic filed and a stray magnetic field in a uniform region ball domain of the magnet.

The invention discloses a three-dimensional magnetic field generation device, comprising three groups of mutually orthogonal one-dimensional magnetic field generators. By adjusting side length sizes of a main coil and an auxiliary coil, relative space positions of the main and auxiliary coils and ampere-turns of the main and auxiliary coils and utilizing the linear relationship between an magnetic field and an electric current, enlargement of a magnetic field homogeneity range in a limited space is realized by adopting a constant-current direct-current power supply to drive the main and auxiliary coils. Compared with any traditional round or square Helmholtz coil, for generating the same magnetic field homogeneity range and magnetic field homogeneity, the limited space needed by the three-dimensional magnetic field generation device is greatly reduced by about 2 to 3 times, and the device is suitable for application occasions with higher requirements on the magnetic field homogeneity range and the magnetic field homogeneity in limited spaces.

The invention is a central column for a spherical tokamak magnet toroidal field coil, composed of inner and outer profile conductor layers, where all profile conductors are circumferentially and uniformly distributed; sections of 12 profile conductors are trapeziform in shape, and short bases of them are circularly arranged opposite to the center of the central column; centers of them are formed with natural air flow cooling holes; sections of 12 outer profile conductors are of a quasi-trapezoid with an long arc side in shape, the arc bases of them are opposite to outer surface of the central column and circularly arranged outside the inner profile conductors to form the outer layer of the central column. The top-end and bottom-end terminals of each profile conductor are connected with a turning arm to form a turn of the toroidal field coil, thus forming 24 turns in common; there is a current flowing through each profile conductor and these currents are codirectional and equal, corresponding to ampere-turn of the toroidal field coil. The invention can permit the maximum 12000A pulse current to flow through the toroidal field coil but the inner temperature does not obviously rise.

A rectifier transformer with self-couple compensation and shielding harmonic is disclosed. The self-couple tap is led out from the secondary winding in the supply transformer, this tap divides the secondary winding into two stages: the analogous auto-transformer common winding and series winding. Both of them are coupled closely, the secondary windings of the two stages and primary winding are arranged with one center on the iron core cylinder, specially the common winding is arranged between the primary winding and series winding, its equivalence impedance value is zero. The both ends of common winding connect to the bypass of external filter capacitor inductance. The invention can take reactive compensation for inductive current at user's power frequency. Utilize the Ampere-turn balancing action of two windings divided by tap at relevant harmonic frequency to neutralize the harmonic current, thereby leads the harmonic current to return to load nearby through series winding and prevents the harmonic current from crossing the air gap into primary power network. It also prevents the harmonic magnetic flux from damaging to the transformer.

This invention relates to reed switches, and more particularly to micro-miniaturized reed switches and batch microfabrication techniques used to fabricate micro-miniaturized reed switches. The present invention can provide miniaturized reed switches with more consistent operating parameters, and that can be produced more efficiently than conventional reed switches. The present invention can also provide methods of making miniaturized reed switches using microfabrication techniques. The present invention can use lithographic-based fabrication to enable monolithic construction of a reed switch. Microlithography can repeatedly form micrometer dimensions with tight tolerances over large arrays of devices which, if the patterns are translated into materials appropriate for electromechanical devices, can provide for repeatable and consistent electromechanical operation. For example, tight dimensional control of the gap between two reeds in a reed switch or a reed and a fixed contact can provide consistency of performance between reed switches. Thus, the present invention can allow the commonly regarded reed switch specification of sensitivity, or “Ampere-turns” required to close a reed switch, to be tightly controlled with a commensurate reduction in spread in sensitivity across reed switch production lots.

The invention discloses a cathode center layout of a Hall thruster. By means of the cathode center layout, the uniformity of plasma in a discharge channel can be improved, the coupling voltage between a cathode and a discharge chamber is reduced, plume neutral loss energy is reduced, and the efficiency of the thruster is effectively improved finally. A cylindrical cavity penetrating through an inner winding column and an inner pole shoe is formed in the inner winding column and the inner pole shoe of an existing Hall thruster structure along the center axis of the Hall thruster first; afterwards, the ampere turns of coils on the inner winding column and an outer winding column of the Hall thruster are adjusted till a magnetic field meeting the requirement of a discharge chamber channel of the Hall thruster is obtained, and the magnetic field of the inner winding column is in an unsaturation state; and finally, a cylindrical cathode body structure is placed in a cavity of the inner winding column, and a ceramic sleeve is installed between the cathode and the cavity of the inner winding column.

The invention relates to a method and an apparatus for measuring a harmonic characteristic of a current transformer. An equal ampere-turns method is employed as well as a primary loop fundamental wave current circuit and higher harmonic current circuits are formed by superposition and combination, so that harmonic characteristics of various current transformers or current sensors can be detected. Meanwhile, the method is also suitable for manufacturing a current source with high capacity equal ampere-turns harmonic standard and for tracing a source of a measuring system. According to the invention, with regard to detection on a harmonic characteristic of a current transformer or a current sensor, reliability and accuracy of calculation on high-capacity power harmonic electric energy can be improved and reliable bases are provided for equipment configuration and parameter selection of power harmonic treatment; in addition, the utilization of the method can be expanded to measuring field of transient characteristics of a high-capacity current transformer and a high-capacity current sensor.

The invention relates to a ship degaussing winding ampere-turn adjusting device which belongs to the technical field of ship degaussing cable connecting facilities. The ship degaussing winding ampere-turn adjusting device comprises a module base consisting of one or more units, a first external cable connecting mechanism arranged in a first busbar groove, a second external cable connecting mechanism arranged in a second busbar groove, an electrical connecting mechanism arranged in the cavity of the electrical connecting mechanism and electrically connected with the first external cable connecting mechanism and the second external cable connecting mechanism, a general bus mechanism fixed on the module base, and a pair of first and second move adjusting mechanisms respectively matched with the electrical connecting mechanism in a sliding way. The ship degaussing winding ampere-turn adjusting device has the advantages of not only completely eradicating circuit chaos, misconnection, wiring unreliability and safety problems caused by renovating circuits and wiring, but also realizing rapid adjustment, saving time and lightening the work intensity of operators.

The invention relates to a 66kV burst short circuit transformer. A three-phase three-limb iron core is arranged in a lower fuel-saving box of the transformer. The iron core is sleeved with a low-voltage coil and a high-voltage coil. Wires are led out from the head end of the high-voltage coil and the head end and tail end of the low-voltage coil in the axial direction, and are led into a sleeve through cables. The high-voltage coil is of a fully continuous structure, wherein every two of three composite conductors are wound in parallel in the radial direction. A subsidiary pressing plate on the high voltage side and a subsidiary pressing plate on the low voltage side are respectively of a fan shape as a whole, and the fan-shaped subsidiary pressing plate on the high voltage side and the fan-shaped subsidiary pressing plate on the low voltage side share the same center of a circle and are placed in a symmetric mode. The subsidiary pressing plates and a pressing plate are provided with positioning holes and are connected through an insulating screw rod. According to the 66kV burst short circuit transformer, the insulation structures of the coils are optimized, ampere-turn balance of the coils is improved, horizontal eddy current loss of the coils is lowered on the premise that insulation reliability is guaranteed, the stress level of the coils is lowered substantially at the time of a short circuit, the capability in resistance to the short circuit of a product is enhanced, and a basis is provided for further optimization of a product design.

The invention provides a high-precision current comparator, which comprises a current transformer assembly and an annular ampere turn balance indicator coaxially arranged in the center of the current transformer, wherein the current transformer assembly comprises a primary iron core, a secondary iron core coaxially arranged in the primary iron core, a corresponding primary winding, a secondary winding, a primary compensation winding and a secondary compensation winding; the ampere turn balance indicator comprises a measurement error compensation winding, a detection winding and a tertiary iron core; the tertiary iron core is arranged in an inner magnetic shielding piece; and the measurement error compensation winding is wound on the inner magnetic shielding piece. The high-precision current comparator provided by the invention has the advantages that influences from magnetic errors and capacitive errors can be reduced; the accuracy level of the current comparator is improved; the current comparator is applied to the highest standard in a self calibration system; the error accumulation value during a measurement downward transfer process can be reduced; the measurement accuracy of the current comparator self calibration system is enhanced; and the accurate application of the current comparator in the industry can be ensured.

The invention provides an electric vehicle AC charging connection device with a measurement and detection port. A detection port is arranged at a charging connection device end of an AC charging point; the electromagnetic induction and equivalent ampere-turns principles are adopted to convert the AC in the charging connection device into a voltage or current signal with measurable measurement standards, and the electric signals are measured and detected. The electric vehicle AC charging connection device with a measurement and detection port can detect the actual consumed electric energy of electric vehicles, can detect the actual electric signals received by the electric vehicle, and can detect the charging point of the electric vehicle without opening a shell of the charging point for wiring, so as to facilitate the detection process of detection personnel, improve the detection efficiency, and also improve the detection reliability and security greatly. The electric vehicle AC charging connection device with a measurement and detection port can input standard signals and automatically calibrate the current measurement error.

The invention discloses a method for determining the ampere-turn change percentage range of a coil according to a dynamic magnetic field associated with coupled oscillation in a Hall thruster, belongs to the field of aerospace aviation, and aims to solve the problem of inaccurate ampere-turn change percentage range of the coil of the Hall thruster determined by using a static magnetic field. The method comprises the following steps: I, importing a two-dimensional symmetrical model of the Hall thruster into an FEMM to build a magnetic circuit model; II, introducing initial current into three coils in a simulating manner to generate a static magnetic field, and acquiring the zero coordinate position of the static magnetic field; III, gradually changing the value of current introduced into one of the coils at the step length of 20 percent to obtain a corresponding curve graph of the ampere-turn change percentage of the coil and the zero magnetic field position change percentage; IV, determining the range of the ampere-turn change percentage of an outer coil according to the specification that the deviation distance between the zero coordinate position of the dynamic magnetic field and the zero coordinate position of the static magnetic field is 2-2.5 percent lower than the channel feature size and the step III.

The invention relates to a high-capacity double-body split on-load voltage-regulating transformer belonging to the technical field of transformers. The technical scheme is as follows: two transformer bodies (1, 2) which are same in structure are arranged in a transformer oil tank, namely two triphase double-coil on-load voltage-regulating transformer bodies each of which has capacity equal to half of total capacity are positioned in one oil tank and are arranged in parallel from front to back along the short shaft direction of the transformer; the high voltage of the transformer is subjected to on-load voltage regulation, and the low voltage is split into two low voltage windings (3); the low voltage windings of two central pillars on each body are respectively led outsides; the two triphase low voltage windings are respectively formed into two corniform links; a high voltage winding (4) and a voltage regulating winding (5) of the two central pillars on each body are led outsides after being connected in parallel; and the triphase high voltage winding is a stratlike link. According to the high-capacity double-body split on-load voltage-regulating transformer, the mechanical force of the high-capacity split transformer when in a sudden short circuit can be effectively reduced, the short circuit damage of the transformer caused by asymmetric ampere turns in half-penetrating short circuit is avoided, and the safety and the reliability in production operation are enhanced.

A magnetic flux generated by current excitation is allowed to run over a portion of the magnetic path of a leakage magnetic flux or the entire magnetic path thereof. The amount of the magnetic flux generated by the current excitation is changed in terms of time to change the amount of the leakage magnetic flux crossing a detection coil, an induction voltage is generated in the detection coil, and consequently a flaw can be detected even in the case where there is no relative rate between a wire rope and a wire rope flaw detector. Further, the shape of the magnetic path and the number of ampere turns of the exciting coil are set to be appropriate to prevent the magnetic flux generated by the current excitation from running through the detection coil and make the magnetic flux get balanced out. Thus, noise superimposition to the detection coil generated by current excitation can be prevented.

The invention discloses a detection method and system which are used for detecting an error of a self-correcting current transformer. The system comprises a core integrity detection unit, a winding turn number detection unit, an error accuracy measurement unit and a security coefficient detection unit. The system does not need to use a large-capacity strong current generator or bear a long wire with thousands of amperes when performing error measurement on a current transformer coil, thereby reducing the working intensity in error measurement of the field current transformer. The system enables the current transformer coil to complete core performance checking under all operating conditions when 1A small current is inputted into the current transformer coil by adopting a mode of externallyconnecting a 1A:1A small standard instrument. According to a principle of equal ampere-turns, an external coil with the turns ratio being the same as that of a detected coil is adopted to be comparedwith the detected coil, and the number of turns of the coil is enabled to be accurately measured under low current.

The invention provides an optical mutual inductor calibration and operation monitoring method and a system so as to solve the problem that measurement is inconvenient. The system comprises a computer, a calibration module, an on-line operation monitoring module, a current generation module, a combination unit, a computed tomography (CT) electrical unit, a fiber optical current transformer (FOCT) optical cable, a gas insulated switchgear (GIS), an equal ampere-turn cable and an equal ampere-turn optical fiber sensitive ring. The current generation module generates current signals. The equal ampere-turn cable amplifies the current signals penetrating through the equal ampere-turn sensitive ring. The calibration module collects the current signals inside the equal ampere-turn cable as the standard signals, receives detected current received by the CT electrical unit at the same time after framing of the combination unit, and transmits the detected current in a packaging mode to the on-line operation monitoring module. The on-line operation monitoring module processes received data, obtains ratio error value and angular difference value of a calibrated optical mutual inductor, and sends the ratio error value and the angular difference value to the computer. The method and the system monitor performance index of the optical mutual inductor on the condition that power is not off in real time, and are safe, high in calibration precision, fast in speed, and high in efficiency.

The electromagnetic Al-Si alloy quenching and tempering process includes the following steps: smelting Al-Si alloy at 800-1000 deg.c; adding other alloy elements, if necessary, and raising the temperature to 740-840 deg.c to deair the alloy elements; casting in a semi-continuous casting machine at the temperature 80-150 deg.c higher than the liquid line and the casting speed of 70-130 mm/min while applying low frequency electromagnetic field of 15-50 Hz and magnetic field strength of 10000-20000 ampere-turns. The electromagnetic Al-Si alloy quenching and tempering method has the advantages of simple process, obvious quenching and tempering effect of fining both the symbiotic crystal structure and initial crystal structure, very low cost and easy application in industrial production.

The invention discloses a split type winding structure, which realizes the balance of ampere turn between a primary winding and a secondary winding, prevents the windings from being damaged, reduces investment cost and reduces loss. The invention has the technical scheme that the split type winding structure comprises a first primary winding, a second primary winding and a secondary winding, wherein the first primary winding comprises the first part of the first primary winding and the second part of the first primary winding which are wound by layers and connected in series or in parallel, the second primary winding comprises the first part of the second primary winding and the second part of the second primary winding which are wound by layers and connected in series or in parallel, the secondary winding is wound at the outer side of the split type winding structure, and the first primary winding and the second primary winding are wound at the inner side of the split type winding structure.