108 results about "Lorentz force" patented technology

The invention discloses a novel induction-type magneto-thermo-acoustic detection method for the conductivity of a supercapacitor, and relates to the technical field of nondestructive material detection.The method comprises the steps that a steady-state static magnetic field and a pulse alternating magnetic field are introduced to form a composite excitation field, and a magneto-acoustic effect and a thermo-acoustic effect are simultaneously and cooperatively excited in a solid-state electrode material; the magnetoacoustic-thermoacoustic coupling effect is formed, eddy current induced by a pulse alternating magnetic field in the material not only generates joule heat, but also generates a direct carrier of Lorentz force under the action of a steady-state static magnetic field, the two physical effects are derived from the same electromagnetic excitation process, but the mechanisms for generating acoustic signals are complementary to each other, so that the effect of the magnetoacoustic-thermoacoustic coupling is achieved. The two effects are coupled as a unified sound source item, a sound pressure wave equation is established, the equation describes a sound field excitation process under the combined action of a force source and a heat source, the coupling mechanism remarkably enhances the strength and information abundance of ultrasonic signals, and the inherent defect that a single thermoacoustic detection method is insensitive to a high-conductivity material is overcome.

The invention provides a magnetic field enhanced SF6 circuit breaker intelligent control method and device. According to the method, waveform feature extraction and spectral analysis are carried out by acquiring arc state parameters, an intelligent decision model is constructed by adopting a hybrid machine learning and reinforcement learning algorithm to generate an optimal arc extinguishing control strategy, and differential control is implemented in different stages of an arc: an electromagnetic coil is activated in the initial stage to generate a high-intensity magnetic field to apply Lorentz force; synergistically adjusting the magnetic field and airflow in the middle stage, and strengthening airflow cooling in the later stage; meanwhile, the medium recovery characteristic is monitored, the reignition probability is calculated in real time, protection measures are triggered, the fault diagnosis function is integrated, intelligent arc extinguishing control over the SF6 circuit breaker is achieved, and the large-current breaking capacity and reliability are remarkably improved.

The invention relates to an N-pole module assembly of a circuit breaker and the circuit breaker. The N-pole module assembly of the circuit breaker comprises a main body function module and a current detection module, and further comprises a first N-pole conductive plate fixedly integrated on the main body function module and a second N-pole conductive plate fixedly integrated on the current detection module, and the main body function module and the current detection module are respectively two independent modular structures. And the first N-pole current-conducting plate and the second N-pole current-conducting plate are fixedly and electrically connected to form an N-pole electric loop. According to the invention, the complicated bending and wiring process of the soft wire in the N-pole module assembly in the prior art is avoided, the assembly is convenient, and the automatic assembly can be realized. Moreover, through the special arrangement of the relative positions of the N-pole electric loop and the L-pole electric loop, the Lorentz force generated by the magnetic field generated by the current on the N-pole electric loop on the electric arc in the circuit breaker unit can assist the electric arc to be further pushed and lengthened, and the effect of enhancing the magnetic quenching function can be achieved.

The invention provides a magnetic resonance guided charged particle beam radiotherapy device and an electromagnetic navigation parameter debugging method for target coordinates, and belongs to the technical field of radiotherapy devices. The system comprises a charged particle beam electromagnetic navigation device which comprises multiple stages of electromagnetic navigation coils, charged particle beams sequentially pass through the multiple stages of electromagnetic navigation coils, and parallel charged particle beams consistent with a magnetic resonance main magnetic field in direction are generated; the MR imaging device comprises an MR main magnetic field coil upper group and an MR main magnetic field coil lower group, and an imaging treatment area is formed between the MR main magnetic field coil upper group and the MR main magnetic field coil lower group. The electromagnetic navigation parameter debugging method comprises the steps of constructing a target cost function, optimizing electromagnetic navigation parameters based on an optimization algorithm without gradient information, and determining and outputting optimal navigation parameters. According to the invention, the charged particle beam parallel to the MR main magnetic field can be generated, the influence of Lorentz force on the charged particle beam is greatly reduced, the difficulty of positioning a tumor target region by the charged particle beam under the guidance of MR can be reduced, and the treatment accuracy is improved.

The invention discloses a multi-parallel coil electromagnetic Hopkinson bar and a cooperative control method, and the multi-parallel coil electromagnetic Hopkinson bar comprises a controller which is used for controlling the discharge time of a plurality of capacitors; the plurality of capacitors are respectively used for discharging according to the discharging time; the main coil is used for generating a corresponding target Lorentz force in response to the discharge of the capacitor so as to apply an impact load to the tested piece by using the target Lorentz force and complete the dynamic mechanical property test of the tested piece; wherein the main coil comprises a plurality of sub-coils which are arranged in a symmetrical annular array; each sub-coil is of an annular spiral structure, and any two adjacent sub-coils are different sub-coils; and each capacitor is connected with the corresponding sub-coil.

The invention discloses an oil paper insulation life evaluation method, device and equipment of a converter transformer and a medium, and relates to the technical field of electric power engineering, and the method comprises the steps: building an insulation life improvement model based on a linear cumulative damage theory and a thermal aging model; carrying out numerical solution on the electromagnetic field and the solid force field to obtain Lorentz force density and mechanical damage accumulation equivalent stress distribution, and determining an equivalent stress translation factor by utilizing the mechanical damage accumulation equivalent stress distribution; solving numerical values of the oil paper insulation space temperature field and the electromagnetic field to obtain total eddy current loss, and determining a temperature translation factor based on the Lorentz force density, the total eddy current loss and the oil paper insulation space temperature field; calculating total acceleration factor distribution by using the equivalent stress translation factor and the temperature translation factor, inputting the total acceleration factor distribution into the insulation life improvement model, and outputting space life distribution; and carrying out oil paper insulation life evaluation on the converter transformer, realizing quantitative evaluation on insulation fatigue damage under the action of cyclic load, and comprehensively evaluating the life of an insulation material.

This invention discloses a high-performance electromagnetic pulse (EMP) welding process for tubular components, comprising the following steps: configuring a corresponding intermediate layer and drive tube according to the welding process requirements of the target weldment; sequentially assembling the inner tube, intermediate layer, and outer tube; sequentially assembling the drive tube, magnet collector, and electromagnetic generating coil; setting the charging voltage and energy storage level of the pulse capacitor; charging the pulse capacitor bank in the charging circuit to a preset voltage; rapidly discharging the high-voltage electrical energy stored in the capacitor bank to the electromagnetic generating coil to generate a transient strong magnetic field; a huge Lorentz force is induced inside the drive tube, propelling the outer tube to violently impact inward at extremely high speed. This invention can achieve high-performance electromagnetic pulse welding of multi-property material combinations and multi-size tubular components; through the design of the magnet collector and drive unit, it achieves electromagnetic pulse welding of low-conductivity, small-gap tubular components; and innovatively proposes the concept of an intermediate layer, thereby realizing the welding of dissimilar or high-performance, difficult-to-join metals.

The application relates to the technical field of plasma, in particular to a processing device for coaxial pulse trapezoidal magnetic field regulated plasma jet, which comprises a gas-liquid control module, a plasma generation module, a pulse trapezoidal magnetic field generation module, a power excitation module, a synchronous controller and a plasma processing module; the pulse trapezoidal magnetic field generation module is connected with the plasma generation module and is used for generating a coaxial pulse trapezoidal magnetic field with adjustable parameters; the radial component of the coaxial pulse trapezoidal magnetic field is perpendicular to the movement direction of charged particles in the plasma jet, the plasma jet is provided with a radial expansion or contraction Lorentz force, and the processing area of the plasma jet is adjusted. The device provided by the application generates a stable, dispersed, gas-temperature-near-room-temperature and adjustable-action-area plasma jet, realizes efficient, accurate and low-energy-consumption processing of a target object, and achieves good processing effect.

The invention discloses a soot blowing pipeline wall thickness online monitoring method based on temperature self-adaption, and relates to the technical field of industrial pipeline nondestructive testing. The problems that in the prior art, a detection signal is unstable in a high-temperature environment, and the micro corrosion thinning recognition precision is insufficient can be at least partially solved. The method comprises the steps that the surface temperature of a pipeline is collected, and the force contribution ratio of Lorentz force to magnetostriction force is calculated; dynamically optimizing electromagnetic ultrasonic body wave excitation parameters according to the force contribution ratio; body waves are excited point by point in the axial direction of the pipeline, and echo signals are collected; extracting bottom wave features by using empirical mode decomposition and wavelet threshold combined noise reduction; calculating the wall thickness of each measuring point based on the temperature correction sound velocity; and generating a B-scan image and carrying out grading evaluation according to the percentage of the thinning amount. According to the method, the wall thickness is accurately measured under the high-temperature working condition, signal stability is ensured through temperature self-adaptive parameter optimization, the signal-to-noise ratio is remarkably improved through combined noise reduction, wall thickness distribution is visually presented through B scanning imaging, and reliable data support is provided for safe operation and maintenance of a pipeline.

external magnetic field - coil with right-hand winding (4) resting on the outer surface of the annular cathode electrode as an encompassing device to generate a magnetic field which, in interaction with the electrolyte current, causes a "Lorentz force" to magnetohydrodynamically accelerate the faster detachment of hydrogen gas bubbles from the outer cathode surface

The invention discloses a gallium oxide-based transverse FinFET (FinFET) device with high electron mobility, which mainly solves the problems of small channel mobility and large on-resistance and thermal resistance effects of the existing similar devices. The device comprises a substrate (1), a barrier layer (2) and a channel layer (3) from bottom to top, the channel layer (3) adopts a Fin structure, a source electrode (4) and a drain electrode (5) are respectively arranged at two ends of the channel layer (3), and a gate dielectric layer (6) and a gate electrode (8) are arranged between the source electrode and the drain electrode; a magnetic thin film layer (7) is arranged on the gate dielectric layer corresponding to the groove between the Fin channel layers and is used for providing magnetic field force in a channel and applying Lorentz force from bottom to top to moving electrons, so that the channel electrons perform directional movement under the synergistic effect of the Lorentz force and the electric field force, the probability of electron collision and scattering is reduced, and the performance of the device is improved. And the carrier mobility of the device is improved. Under the condition that the process complexity is not increased, the on resistance and the thermal resistance effect of the device can be effectively reduced, and the device can be used as a power electronic device.

The invention discloses a liquid metal passive self-driven thermal control system and method based on thermoelectric effect and magnetic field cooperation, and belongs to the technical field of thermal control of electronic equipment. The two end faces of the thermoelectric module are tightly attached to the heating device and the cold plate respectively. The thermoelectric module comprises a ceramic substrate, and an electrode is electroplated on the surface of the ceramic substrate; between the ceramic substrates, the thermoelectric crystal grains are electrically connected in series and thermally connected in parallel to form a columnar array, the columnar array is welded on the electrodes, and an external wire is welded. The electrode is embedded into the wall surface of the cold plate and connected with the output end of the thermoelectric module, the potential difference generated by the thermoelectric module is applied to the electrode, and current is formed in the liquid metal; the liquid metal working medium is sealed in the cold plate, the electrified liquid metal working medium is subjected to the effect of Lorentz force under the effect of an external magnetic field, liquid metal is driven to flow in one direction, and heat exchange is enhanced. Reliable technical support is provided for efficient heat dissipation of the electronic equipment.

The utility model provides a kind of vertical metal separator, including shell, reel, electrostatic cylinder and separation magnetic plate;Shell is hollow box, the top of which is provided with feeding inlet, the bottom of feeding inlet is provided with reel, first comb tooth is arranged on it, electrostatic cylinder is arranged on the side of reel, and the side of electrostatic cylinder is provided with toothed groove, first comb tooth and toothed groove are engaged with each other, and form feeding channel;The bottom of feeding channel is provided with separation magnetic plate;Separation magnetic plate includes first magnetic plate and second magnetic plate, and the magnetic pole of first magnetic plate and second magnetic plate is oppositely arranged, and is arranged at a certain distance to form magnetic field separation channel;The utility model is in application, metal impurities are carried charge in falling process, and the Lorentz force generated by magnetic field is used, metal impurities are deviated in falling process, and then material and metal impurities can be separated.Therefore, the utility model realizes the separation of metal impurities at lower cost, and waste is reduced.

The application belongs to the field of hypersonic active flow control, and discloses a drag reduction and heat protection system and method for a hypersonic aircraft. The method combines energy deposition and magnetic fluid flow control. Energy deposition has excellent drag reduction characteristics, which can bring good drag reduction effect to the aircraft. Meanwhile, energy deposition can be used as auxiliary ionization technology to improve the magnetic control effect of magnetic fluid flow control by improving the electrical conductivity of the fluid. Magnetic fluid flow control has outstanding heat protection performance, which can bring excellent heat protection effect to the aircraft after dealing with the heat flow growth caused by energy deposition. Meanwhile, the Lorentz force of the magnetic field fully suppresses the resistance impact and shock caused by pulse energy deposition. The method can achieve better hypersonic drag reduction and heat protection effect, effectively reduce the resistance of the hypersonic aircraft and improve the heat protection ability of the aircraft, and has wide application prospect.

A beam diffusion and convergence control system based on an annular electrified multi-conductor angular magnetic field is used for regulating and controlling the beam spot size and the beam divergence angle of a charged particle beam, diffusion and convergence of beams can be achieved, and the transverse size of the beams can be enlarged and reduced. A hardware implementation carrier of the charged particle beam diffusion and convergence regulation and control method mainly comprises an annular electrified multi-conductor device and an exciting current source. An ideal axisymmetric angular magnetic field can be generated in the annular energized multi-conductor device, so that the diffusion or convergence motion state of charged particle beams can be realized under the condition that only one group of annular energized multi-conductor devices is adopted based on the action of Lorentz force in a centrifugal or centripetal direction; the intensity and direction (clockwise or anticlockwise) of the angular magnetic field in the device can be randomly adjusted by adjusting the direction and amplitude of the exciting current; theoretically, the beam spot radius of the charged particle beam can be adjusted by 1-3 orders of magnitude or more.

The invention discloses a superconducting cable Lorentz force analysis method and device considering electric field force, and the method comprises the steps: building an equivalent circuit model of each conductor layer of a superconducting cable, and enabling the equivalent circuit model to comprise the variable resistance and self-inductance of each conductor layer, and the mutual inductance between the conductor layers; obtaining current and voltage parameters of each conductor layer of the superconducting cable under the target working condition; calculating spatial magnetic field distribution around each conductor layer based on the current, the geometric parameters and the winding direction of each conductor layer, and calculating the magnetic field force density per unit area borne by each conductor layer; calculating a potential difference between adjacent conductor layers based on the voltage parameter of each conductor layer, and calculating a unit area electric field force borne by each conductor layer according to the potential difference; and performing vector synthesis on the unit area magnetic field force density and the unit area electric field force to obtain the total Lorentz force borne by each conductor layer so as to evaluate the stress condition of the superconducting cable under each working condition.

The application relates to the technical field of material mechanical property testing, in particular to a material Young's modulus measuring device based on an electromagnetic-capacitive coupling mechanism and application. A non-magnetic support structure comprises a top wall, a side wall and a bottom wall, the top wall is provided with a guide structure on the side facing the bottom wall, the bottom wall is provided with a bottom opening, an electromagnetic driving unit comprises a magnetic ring arranged on the inner wall of the side wall and a coil coaxially arranged in the magnetic ring, the coil is electrically connected with an external power supply and reciprocally moves along the axial direction under the driving of a square wave electric signal to generate a controllable Lorentz force; a capacitive sensing unit comprises a first capacitive electrode and a second capacitive electrode, the first capacitive electrode is fixed on the guide structure, and the second capacitive electrode is fixed on the inner side of the coil. By coaxially integrating the electromagnetic driving unit and the capacitive sensing unit in a compact physical structure, a complete "excitation-response-parameter inversion" closed-loop measurement link is realized, and the detection sensitivity, measurement precision and stability are significantly improved.

This invention relates to the field of variable capacitor technology, and in particular to a non-contact electrostatic detection device, comprising a carrier assembly including a circuit board; a sensing component disposed inside the carrier assembly; and a deformable component disposed above the carrier assembly. The carrier assembly further includes a shielding cover disposed above the circuit board and an opening slot on the shielding cover. A cavity is formed inside the shielding cover, and a sliding groove is formed at one end of the cavity. The sensing component includes a shielding plate disposed within the sliding groove, and a limiting protrusion is provided at one end of the shielding plate. The shielding plate and the limiting protrusion are L-shaped. This invention utilizes the Lorentz force generated by the components within the deformable component. This Lorentz force, in conjunction with the reciprocating vibration of the shielding electrode upon contact with an elastic element, avoids the mechanical wear associated with traditional motor solutions, thus extending the service life.

The application discloses a driving assembly and a driving device of liquid metal. The driving assembly is arranged on a rotating shaft and comprises a pair of oppositely arranged rotating discs, a surrounding component and a flat flow channel component. There is a working interval between the two rotating discs. Each rotating disc is fixedly connected with a magnet block array on a side facing the other rotating disc and generates a circumferential rotating magnetic field in the working interval when being driven. The surrounding component is arranged on each rotating disc and comprises a retaining ring and a plurality of interval arranged metal baffles. Each metal baffle and part of the components of the retaining ring partially wrap and limit the magnet blocks. The flat flow channel component is arranged in the working interval and is sleeved on the outside of the rotating shaft. The liquid metal flows in the flow channel component from an inlet to an outlet. The liquid metal is provided with driving force in the flow in the flow channel component due to the Lorentz force generated by the circumferential rotating magnetic field.

This invention provides a dual-stator self-regulating electromagnetic pump for high-temperature conductive media, comprising a first pipe and a second pipe, the second pipe being coaxially disposed inside the first pipe, forming an annular cavity between the first pipe and the second pipe for the flow of the high-temperature conductive media; an outer stator assembly is disposed outside the first pipe, the outer stator assembly being configured to generate a traveling wave magnetic field, the traveling wave magnetic field being used to act on the high-temperature conductive media within the annular cavity and generate a Lorentz force to drive the high-temperature conductive media to flow along the annular cavity; at least one set of regulating stators is disposed axially inside the second pipe, the regulating stators being used to generate a compensating magnetic field acting on the high-temperature conductive media within the annular cavity to increase the Lorentz force on the high-temperature conductive media.

Optical device (1) comprising: - an optical element (21) configured to interact with a light beam (L) when the light beam hits the optical element (21), - a supporting structure (3) configured to support the optical element (21), - at least one elastic element (600, 90) connected to the supporting structure (3) and the optical element (21) such that the optical element (21) is movable with respect to the supporting structure (3), - an actuator (5) configured to move the optical element (21) by means of a Lorentz force, wherein the actuator (5) comprises a first coil (60) and a second coil (61), each coil comprising several turns, the turns of the respective coil (60, 61) extending around a winding axis (W) of the respective coil (60, 61), the coils (60, 61) being integrated into the supporting structure (3), and wherein the actuator (5) comprises a first magnet (70) facing the first coil (60) and a second magnet (71) facing the second coil (61), the first and second magnets (70, 71) being connected to the optical element (21), and wherein the magnets (70, 71) each have a magnetization (M1, M2) perpendicular to the winding axes (W) of the coils (60, 61) extending plane at an angle (α) between 80° and 100°, wherein the supporting structure is a supporting frame (3),which is configured to support the optical element (21), wherein the support structure (3) surrounds an opening (31) of the support structure (3) extending from a front (3a) of the support structure (3) to a rear (3b) of the support structure (3) so that light can pass through the support structure (3), wherein the at least one elastic element is a first spring structure (600) connected to the front (3a) of the support frame (3), wherein the first spring structure (600) comprises a first frame (607) to which the optical element (21) is connected, wherein the first frame is tiltable about a first axis (A) with respect to the support frame (3), and wherein the actuator is configured to tilt the optical element about the first axis (A), wherein the support frame (3) comprises a first arm (350) opposite a second arm (351) of the support frame (3), and wherein the first arm (350) and the second arm (351) by a third and a fourth arm (352,353) of the support frame (3), and wherein the optical element is a transparent plate (21) for refracting a light ray (L) when the light ray passes through the plate (21).

The invention relates to the improvement of the cooling efficiency of electric motors by utilizing the internal magnetic field and magnetic fluids, aiming to enhance convective heat transfer for improved cooling performance. In this invention, cooling channels are positioned near the coil windings and stator regions—where heat generation is most intense—by making use of the magnetic field already present within the motor. Magnetic fluids (magnetic liquid metals or magnetic nanofluids) are employed as the coolant, and magnetohydrodynamic (MHD) effects are induced through the Lorentz forces exerted by the magnetic field, which alter the flow velocity profile and enhance convective heat transfer. By this method, while the motor temperature is reduced, its cooling capacity is significantly increased. The invention comprises the components rotor (1), stator (2), shaft (3), coil windings (4), housing (5), magnets (6), and cooling channels (7).

The invention discloses a transformer physical state calculation method and device, a storage medium and a program product, and relates to the technical field of power equipment monitoring. The method comprises the following steps: constructing an electromagnetic field model of a tested transformer based on a structure measurement result of the tested transformer; coupling the solid structure and the electromagnetic field of the measured transformer, and solving the electromagnetic field model by using the measured Lorentz force of the transformer box body to obtain the non-diffusion current density of each space point in the transformer box body; based on the non-diffusion current density, Joule thermal power of a coil of the tested transformer is calculated, and the coil temperature of the tested transformer is calculated based on the Joule thermal power of the coil of the tested transformer; and based on the non-diffusion current density, calculating the Joule thermal power of the transformer box body, and based on the Joule thermal power of the transformer box body, calculating the temperature of the transformer box body. According to the invention, general, sustainable and accurate detection of the operating temperature of the transformer is realized.

This invention discloses a method for dynamic modeling of the temperature field and prediction of overheating risk in cable connectors, relating to the field of electrical equipment condition monitoring and thermal management technology. The method includes constructing the connector's geometric domain and establishing a fully coupled electro-magnetic-thermal-mechanical initial value model containing Lorentz force correction terms and eddy current loss heat source terms; jointly assembling the Lorentz force and eddy current loss terms to form a magneto-thermal coupling correction matrix, calculating the equivalent heat source field of a strong magnetic field; solving the temperature field and updating the conductivity and permeability distributions in reverse, forming a bidirectional coupled iterative loop until a converged temperature field is output; extracting hot spot trajectories and temperature gradient vector fields based on the converged temperature field, inputting them into the thermal aging kinetic model of the insulation material to generate a multidimensional indicator surface for overheating risk, determining the risk level and outputting a warning signal. This invention improves the accuracy of connector temperature field prediction and the reliability of overheating risk warning under strong magnetic field environments through bidirectional coupled iterative correction and fully coupled modeling.

The application relates to the technical field of glass substrate static electricity elimination devices, and discloses a static electricity elimination device for glass substrate processing, which comprises a work platform, a cover body and a magnetic field generator. The work platform is provided with a conveying assembly for fixing and transporting glass plates. The cover body is arranged on the work platform and is internally provided with a spray head for spraying water vapor. Magnetic field generators capable of generating magnetic fields are arranged on the two sides of the cover body. The magnetic induction lines of the magnetic fields pass through the glass plates in the cover body. An electron emitter is further arranged inside the cover body and beside the spray head. During work, the magnetic field direction of the magnetic field generator is adjusted after the surface charges of the glass plates are detected. The water vapor generated by the spray head is used for wetting the surface of the glass plates, the surface liquid flow direction is controlled, the charges are moved in the magnetic field, the charges are concentrated under the influence of the Lorentz force, and the accumulated surface charges of the glass plates are neutralized by the electron emitter.

The application discloses a kind of primary-secondary insulation gas ring network cabinet arc extinguishing control method and device, applied to the gas insulation ring network cabinet with magnetic blow coil and solid-state gas production arc extinguishing component in arc extinguishing chamber.The method comprises: collecting gas chamber pressure, temperature and arc current, calculating arc extinguishing gas density;According to gas density, arc current, gas flow injection speed and magnetic induction intensity, the dimensionless force ratio parameter that represents the ratio of gas flow drag force and Lorentz force is calculated;According to the preset coupling angle of force ratio parameter and gas production component, the optimal force ratio parameter corresponding to the maximum of arc extinguishing power density function is solved online;Reverse solve the target drive current of magnetic blow coil to make actual force ratio parameter approach optimal value;According to the cooperative timing drive magnetic blow coil and trigger gas production component to execute arc extinguishing.The application establishes magnetic field-gas flow coupling arc extinguishing mathematical model, realizes adaptive cooperative arc extinguishing control of model driving, and the comprehensive arc extinguishing power density is significantly improved.

The application discloses a method for preventing the explosion of a hollow reactor coil under a large instantaneous current, and adopts a hollow reactor coil with a concentric circular winding structure, improves the state of the Lorentz force of the hollow reactor coil, reduces the influence of the Lorentz force of the hollow reactor coil under a large instantaneous current, and prevents the explosion of the hollow reactor coil under the large instantaneous current. The distribution of the Lorentz force of the hollow reactor coil is improved by adjusting the structure of the hollow reactor coil, so that the shape of the hollow reactor coil is infinitely close to a circle, and the Lorentz force received by the coil under a large instantaneous current is uniformly distributed in the radial direction. The application improves the distribution of the Lorentz force of the hollow reactor coil, reduces the influence of the Lorentz force on the coil under a large instantaneous current, greatly improves the ability of the hollow reactor coil to resist the impact of the current, can resist the impact of a current of several hundred kiloamperes, and does not explode, so that the reactor itself is a product without splinters and other flying objects to damage equipment.

The invention discloses a double-wire variable-polarity pulse MIG welding droplet lateral oscillation transition control method, which comprises a host power supply and a slave power supply, and the output current of the slave power supply comprises an EP base value stage, an EP peak value stage and a variable-polarity oscillation stage; the host power supply output current comprises a base value stage and a peak value stage; the polarity of the output current of the slave power supply is continuously switched in the variable polarity oscillation stage, on one hand, the direction of Lorentz force borne by the two molten drops is continuously changed to generate transverse vibration, necking of the molten drops is promoted, molten drop transition can be accelerated under the condition that the current is not increased, active control over molten drop transition is achieved, and the stability of the molten drop transition is improved. The two molten drops are ensured not to collide in the falling process; and on the other hand, the two electric arcs swing left and right under the action of electromagnetic force, electric arc interference is reduced, a molten pool can be stirred, grains are refined, gas precipitation is promoted, and the welding quality is improved.

The application discloses an electromagnetic flanging device and method capable of maintaining axial dynamic balance of a coil and belongs to the technical field of plastic processing of metal materials. The device comprises an upper die, a lower die, a forming sheet, a balance sheet, a driving coil and a pulse discharge circuit. The driving coil is symmetrically arranged between the two sheets, and the two sheets are consistent in material, shape and thickness. The central aperture of the upper die is slightly larger to allow flanging, and the central aperture of the lower die is slightly smaller to limit deformation. The method comprises the following steps: sequentially placing the balance sheet, the forming sheet and the die, and fastening and closing the switch to discharge. The pulse magnetic field makes the two sheets induce eddy currents and Lorentz forces which are equal in size and opposite in direction, so that axial dynamic balance of the coil is realized. The application solves the problem of instantaneous one-way stress of the coil, avoids high-speed impact, greatly improves the stability of shaft pressure shell and the service life of the device, and is beneficial to batch production.

The application discloses a coaxial pulse plasma thruster with a magnet as an outer electrode, and belongs to the technical field of microsatellite aerospace propulsion. The coaxial pulse plasma thruster with a magnet as an outer electrode mainly comprises an anode, a magnet cathode, a metal cathode, a propellant, an insulating outer shell, an insulating base, a supply spring and a spark plug. The metal cathode is divided into a perforated metal cathode and a non-perforated metal cathode. The thruster is coaxial in shape; the inner electrode is a solid cylinder, the outer electrode is a hollow pipe with a circular cross section, the solid propellant is located between the inner and outer electrodes, the supply spring is arranged between the tail of the propellant and the insulating base, and the outer electrode adopts segmented magnets and metal as the cathode. The application utilizes the magnetic field to restrict the radial movement of plasma so as to improve the collision ionization level, and provides Lorentz force to better accelerate the plasma. The segmented magnetic field provided by the segmented magnets with different magnetic poles opposite to each other can provide the magnetic field while reducing the overall mass of the thruster, and is beneficial to adjusting the magnetic field distribution in the thruster pipeline.