154 results about "Ampere-turn" patented technology

A reluctance motor is provided that reduces leaking magnetic flux. To generate magnetic flux between adjacent magnetic poles in a rotor 2, permanent magnets 4 are disposed in approximate centers of split magnetic paths near a borderline area between two magnetic poles in an internal portion of the rotor. Further, each of slots 8 in a stator 1 is wound with a coil of a corresponding phase such that the vector phase and amplitude expressed by the products of the number of coil turns and the amount of passing current, namely, ampere-turns, become almost identical for each of the slots. By reducing leaking magnetic flux according to this arrangement, generated torque can be increased. As the rotor mechanical strength is enhanced, the rotor can be safely driven at a higher speed. A practical motor is obtained that simultaneously achieves improved motor characteristics and reduced torque ripples.

The invention discloses a mixed excitation permanent magnet flux switching motor which comprises permanent magnets, three-phase armature windings and single-phase excitation windings, wherein the single-phase excitation windings are arranged on a stator, the tooth number of the stator is 4 times number of permanent magnets; and a rotor is in a salient pole structure and has no windings or permanent magnets, thereby having high mechanical strength and being suitable for high-speed operation. An air-gap field comprises an electric excitation magnetic field generated by the excitation windings and a magnetic field generated by the permanent magnets, and is flexibly adjusted by changing an excitation current. An electric excitation magnetic line of force is closed by using an iron core connecting magnetic bridge, which is beneficial to reducing the electric field ampere-turns and lowering the electric excitation copper loss. The armature windings and the excitation windings are distributed in different stator grooves at intervals, which is beneficial to increasing the self-inductance of the armature windings and the mutual inductance of the windings and effectively inhibiting the short circuit current of a motor.

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.

The invention discloses a method and device for measuring direct current magnetic bias error characteristics of a current transformer. Current is simulated into a power frequency current source and a direct-current current source according to an equal ampere-turn principle, wherein the power frequency current source and the direct-current current source are independent, the standard computed tomography CT is used for detecting variation of error characteristics of the measured CT influenced by direct current magnetic bias, a method and device for measuring current comparison type error characteristics or voltage comparison type error characteristics is included, data can be compared in a whole process, and the method and device is suitable for measurement of error characteristics of during direct current magnetic bias of a straight through current transformer and also suitable for checking direct current magnetic bias error characteristics of current transformer coils made of different iron core materials.

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.

A magnetic core antenna system including a magnetic core and a winding network. The winding network may be configured with a non-uniform ampere-turn distribution to achieve a desired flux density in the core. The network may include a plurality of windings configured to provide a winding impedance facilitating optimal transmitter power delivery to the windings. A magnetic core may be constructed from multiple components having longitudinal contact surfaces and joined by a transverse clamping force. An air gap may be provided between the components to allow relative movement therebetween.

The invention relates to a method for restraining crack of high-alloyed aluminum alloy and relative device. Said device is the plate blank electromagnetic continuous casting crystallizer, while the electromagnetic coil is inside water tank; the water baffle plate is arranged inside the water tank; and the crystallizer comprises four water supply chambers which are independently arranged in two large surfaces and two small surfaces; the water supply chambers supply water independently while the water amount is controllable; a shield matter is arranged at the angle; the inlet of melt aluminum alloy at the upper part of crystallizer is mounted with a bridge fusion current divider; and the inner side of internal wall of crystallizer is adhered with thermal isolated film. When using said device to 7000 alloy square blanks whose thickness is 150-450mm, the frequency should be 10-50Hz, and the intensity of magnetic field should be 10000-80000 ampere-turns; at the different process of casting, the water supply chambers supply different water amount; the casting speed is 20-50% higher than present technique. The invention can effectively restrain the crack of high-alloyed plate blank.

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 relates to a super high-voltage current transformer transient characteristics tester. Alternating-current equal ampere-turns bus winding and pulse direct current equal ampere-turns bus winding are respectively winding on the toroid coil of the transient current mutual inductor in acircumference homogeneous distribution mode, the turn number of the two windings is equal, the two windings use common decoupling electric impedance; the alternating-current equal ampere-turns bus winding is connected with the output end of a large-capacity step down transformer through a switch, consisting an alternating-current t equal ampere-turns loop; the direct current equal ampere-turns bus winding is connected with one or two capacitor charged with high voltage through a switch, a reactor and a resistor, consisting a direct current equal ampere-turns loop. The discharging time sequence is operated by a measurement and control apparatus, the desired transient experiment current can be obtained on the ring shaped iron core of the tested transient current mutual inductor when the two loops are combined for discharging. The invention possesses the advantages of novel concept, reasonable design, simple structure, easy operation, reduced experimentation cost of the extra-high voltage transient current mutual inductor and reduced electromagnetic pollution of experiment current to surroundings.

The invention relates to a permanent magnetism mechanism, which comprises an upper case body and a lower case body, wherein, a movable core is arranged between the upper case body and the lower case body; the upper part of the movable core is provided with three upper guide levers. Both sides of the upper guide lever positioned at the middle are provided with a tripping spring and a tripping spring adjusting screw. The upper part of the upper guide lever is provided with an insulator and a contact spring. The position where the lower part of the movable core corresponds to the upper guide lever is provided with a hand trip gear, and both sides of the movable core are provided with a closing coil and a permanent magnet. The invention has the advantages that linear drive is realized on a three step switch tube and the synchronicity and the operability of the three step action are more reliable; the adjustment of the speed of a trip also can be realized; the structure is simple; the cost is low. The invention can be widely used for a breaker and a contactor of a mine feed system, and the environment of the mine feed system is vile, and the mine feed system has high requirement for the reliability. Because the invention only adopts one closing coil, the space of the closing coil is increased. The number of turns of the closing coil can be increased on the premise that the coil diameter is the same or greater than the diameter of the primary coil. The invention can realize frequent electrification for a long time and can not be burnt under the condition that ampere-turn is invariable or the ampere-turn is properly enhanced.

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.

In an electromagnetic switch for auxiliary-rotation starter in the prior technology, it is required to reduce the ampere-turn amount without lowering the pullin coil resistance and it is required to increase the wire diameter of the coil so as to increase the number of turns and to implement opposite winding. There has been a problem that: the assembling performance and the operation are relativebad and the productivity is deteriorated due to increased conductor volume and the opposite winding structure. In an electromagnetic switch for an auxiliary-rotation starter according to the present invention, the magnetic bypass core is disposed at a place that is an air gap portion, in a magnetic circuit, through which the plunger moves due to magnetic attractive force produced by energizing the attraction coil and the holding coil and that is between the outer circumference of the plunger and the inner circumference of the bobbin, in such a way that one end thereof makes contact with one end of the case and the other end thereof faces the end of the core by the intermediary of an air gap.

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.

The invention discloses a vacuum pipeline magnetic suspension train hybrid EMS supporting structure which comprises a vacuum pipeline, a capsule train and a supporting guide part. The capsule train isarranged in the vacuum pipeline in a sleeved mode; a rail armature is arranged on the inner wall of the vacuum pipeline in the length direction of the vacuum pipeline; and the supporting guide part is arranged between the vacuum pipeline and the rail armature. The supporting guide part comprises an electromagnetic coil, an electromagnetic core, a permanent magnet, and safety supporting wheels; the electromagnetic core is arranged at the upper end of the capsule train; the safety supporting wheels are arranged at the lower end of the capsule train; the permanent magnet and the electromagneticcoil are arranged on the electromagnetic core; and the permanent magnet meshes with the rail armature. Zero power suspension is achieved, power consumption of the system is greatly lowered, ampere-turns needed by the coil is reduced, and cost of the train and rail is lowered. The electromagnetic EMS partially applies active control to provide suspension damping, and therefore the train runs more smoothly, comfort is better, space utilization is improved, suspension power consumption is lowered, and cost is lowered.

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.