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35results about How to "Suppression of eddy current loss" patented technology

Three-dimensional porous flower-like structure cobalt/carbon nano-composite electromagnetic wave absorbing material and preparation method thereof

The invention relates to a three-dimensional porous flower-like structure cobalt / carbon nano-composite electromagnetic wave absorbing material. Carbon in the electromagnetic wave absorbing material forms a three-dimensional skeleton in a flower-like structure, and carbon coated cobalt particles are uniformly distributed on a carbon matrix. The preparation method comprises the following steps: 1) serving divalent inorganic cobalt salt as a precursor of cobalt hydroxide, and dissolving the divalent inorganic cobalt salt and surfactant into a solvent according to a certain mass ratio; carrying out reaction under an enclosed condition, and after reaction, carrying out washing and drying on the product to obtain the cobalt hydroxide; carrying out calcination treatment on the prepared cobalt hydroxide to obtain cobaltosic oxide powders; and 2) mixing the cobaltosic oxide powders obtained in the step 1) with a carbon source, and carrying out reaction under an enclosed condition to obtain thethree-dimensional porous flower-like structure cobalt / carbon nano-composite electromagnetic wave absorbing material. The prepared electromagnetic wave absorbing material is high in saturation magnetization, high in coercive force, light in weigh and high in oxidation resistance and has an excellent electromagnetic wave absorption performance.
Owner:SHANDONG UNIV

Iron-carbon nano composite electromagnetic wave absorption material and preparation method thereof

InactiveCN101853727AHigh saturation susceptibilityHigh resistivityInorganic material magnetismGas phaseCarbon nanocomposite
The invention relates to an iron-carbon nano composite electromagnetic wave absorption material and a preparation method thereof. Carbonyl iron, methane and acetylene serving as main raw materials are directly synthesized into the iron-carbon nano composite material in a gas-phase reaction device at the temperature of between 300 and 1,000 DEG C. The nano composite material has good stability and uniformity. The iron-carbon nano composite material is wrapped outside iron nano granules by nano-scale C to form a C film; and the iron-carbon nano composite material has the characteristics of good electromagnetic wave absorption performance, wide absorption coverage frequency range, strong corrosion and oxidation resistance and low cost, and is applicable to electromagnetic shielding in a radio communication system, electromagnetic radiation and leakage of equipment of high frequency prevention, microwave heating and the like, construction of microwave darkrooms and hiding technology.
Owner:SHANDONG UNIV

Three-dimensional porous sheet ferroferric oxide/carbon nanometer electromagnetic wave absorption material and preparing method thereof

The invention relates to a three-dimensional porous sheet ferroferric oxide / carbon nanometer electromagnetic wave absorption material and a preparing method thereof. Carbon in the electromagnetic waveabsorption material forms a three-dimensional framework of a flower-shaped structure, and ferroferric oxide particles wrapped by carbon are evenly distributed on a carbon base body. The preparing method includes the steps of firstly, making trivalent inorganic ferrite and urea as precursors for synthesizing ferroferric oxide dissolved together with a surface active agent in a solvent according toa certain mass ratio to have a reaction under closed conditions, washing and drying a product after the reaction is completed to prepare hydroxyl ferric oxide, and calcinating the prepared hydroxyl ferric oxide to obtain ferric oxide powder; secondly, mixing the ferric oxide powder in the first step with a carbon source to have a reaction under closed conditions to obtain the three-dimensional porous sheet ferroferric oxide / carbon nanometer electromagnetic wave absorption material. The electromagnetic wave absorption material is high in saturated magnetic susceptibility, large in coercivity,light in weight, strong in oxidization resistance and excellent in electromagnetic wave absorption performance.
Owner:SHANDONG UNIV

Method for preparing high-silicon steel from low-silicon steel

The invention belongs to the field of material preparation, in particular to a method for preparing high-silicon steel from low-silicon steel. The method comprises the following steps: a, using a low-silicon steel hot-rolled plate with a smooth surface as a base material, and carrying out cold rolling so as to obtain a thin plate; b, carrying out acid pickling on the thin plate so as to remove oil stains and an oxide film on the surface; c, in a temperature range of 450-550DEG C, carrying out thermal insulation on the cold-rolled thin plate in a solid siliconizing agent for 20-30 minutes; d, in a temperature range of 750-820DEG C, carrying out solid siliconizing on the thermally insulated thin plate for 10-30 minutes in the solid siliconizing agent; e, rolling the thin plate at a temperature of 350-450DEG C; f, at a non-oxidization atmosphere, carrying out diffusion annealing on the siliconized thin plate at a temperature of 850-1100 DEG C for 30-480 minutes; and g, under nitrogen protection, rapidly cooling the thin plate subjected to diffusion annealing to a room temperature and coating a MgO coating. The method is characterized by low raw materials and simple processing and treating. The problems of steel band surface serious corrosion and Fe losses, caused by high Cl-ion concentration in the process of preparing the high-silicon steel by a vapor deposition process are solved.
Owner:NORTHEASTERN UNIV

Magnetic porous cobalt hollow ball electromagnetic wave absorption material, preparation method and application thereof

The invention relates to a magnetic porous cobalt hollow ball electromagnetic wave absorption material, a preparation method and application of the material. The magnetic porous cobalt hollow ball electromagnetic wave absorption material is composed of monodispersed porous hollow balls, wherein the external diameter of each porous hollow ball is 2-6 microns, and the thickness of each ball shell is 100-200nm. The hollow balls are formed by cobalt particles, wherein the diameter of each cobalt particle is 60-200nm, and 10-100nm air voids exist among the cobalt particles. The preparation method includes the steps of using precursors like cobaltous acetate and precipitants like urea, and polyving akohol or polymethyl methacrylate or polyvinylpyrrolidone as surfactants, enabling the surfactants to be dissolved in ethyl alcohol solvents or methanol solvents to obtain cobaltous hydroxides through reaction, and enabling the cobaltous hydroxides and potassium borohydride to be reacted in water or ethanol solutions to obtain the monodispersed porous cobalt hollow balls. The prepared porous cobalt hollow ball material is good in evenness and dispersity, small in density, strong in magnetism and good in electromagnetic wave absorption performance and can be used as the electromagnetic wave absorption material.
Owner:SHANDONG UNIV

Soft magnetic powder used for high frequency mould pressing inductor as well as preparation method thereof

The invention discloses soft magnetic powder used for a high frequency mould pressing inductor as well as a preparation method thereof. The soft magnetic powder is prepared from a first main material,a second main material and an auxiliary material, the first main material is first metal soft magnetic alloy powder with the particle diameter of 1-10[mu]m, the second main material is second metal soft magnetic alloy powder with the particle diameter of 10-15[mu]m, the weight of the first metal soft magnetic alloy powder accounts for 60-99% of the weight of the soft magnetic powder, the weight of the second metal soft magnetic alloy powder accounts for 0-40% of the weight of the soft magnetic powder, and the weight of the auxiliary material accounts for 1-20% of the weight of the soft magnetic powder; and the soft material powder has the advantages of relatively high resistivity and relatively high saturation magnetization intensity, and usage frequency of the mould pressing inductor canbe improved.
Owner:NINGBO YUNSHENG ELECTRONIC COMPONENTS TECHNOLOGY CO LTD +1

End plate, and rotor for rotary electric machine which employs the end plate

An end plate (16) is made of a magnetic material, and holds an axis-direction end surface of a rotor core (14) in which a permanent magnet (20) is buried. The end plate includes: a protruded portion (44) constructed so as to be caused to pressingly contact the axis-direction end surface of the rotor core (14) when mounted in the rotor (10); and a depressed portion (46) constructed so as not to contact the axis-direction end surface (17). The protruded portion (44) is formed so as to contact only one of a d-axis magnetic path region and a q-axis magnetic path region that are formed by the permanent magnet (20) within the rotor core (14).
Owner:TOYOTA JIDOSHA KK

Non-contact electric energy transmission system for vertical drilling system

The invention discloses a non-contact electric energy transmission system for a vertical drilling system. The non-contact electric energy transmission system comprises a transformer, a series resonant inverter circuit, a rectification output circuit and an inverter control circuit, wherein the transformer is a separate transformer which comprises primary magnetic cores and secondary magnetic cores which are separated from one another; a plurality of grooves which are formed along the axis are formed in the outer circular surface of a power main shaft of the drilling system and in the inner circular surface of a hole straightening loop respectively; the primary magnetic cores are arranged in the grooves of the power main shaft; the secondary magnetic cores are arranged in the grooves of the hole straightening loop; the central angle theta formed by the circular arcs on the surfaces of the secondary magnetic cores opposite to the axis of the power main shaft meets a certain relationship, so that the magnetic resistance between the primary magnetic cores and the secondary magnetic cores is constant and is not affected by rotary motion; the phase difference between the voltage and the current is calculated by detecting an output voltage signal and an output current signal of the inverter circuit; the system is kept to work in a resonant state by adjusting the switching frequency, so that the hardware circuit is simplified and the flexibility for phase detection is improved.
Owner:BC P INC CHINA NAT PETROLEUM CORP +1

Superconductor cooling structure used for superconductive magnetic suspension micro thrust measurement system

The invention discloses design of a special superconductor low-temperature cooling structure applied to a superconductive magnetic suspension micro thrust measurement system. The superconductor low-temperature cooling structure comprises a refrigerator, a cooling base, a cooling copper column, a cooling copper ring, a superconductive stator array, an Al<2>O<3> ceramic cover plate, an indium sheet, graphite gaskets, an anti-radiation screen and the like. Specific to the requirements of high cooling efficiency and low eddy current loss of the cooling structure of the measurement system, a dual-path conduction cooling structure with low eddy current effect is designed; according to the cooling structure, the heat conduction gaskets capable of lowering contact heat resistance are arranged on the respective contact surfaces of corresponding parts, and by virtue of setting of the anti-radiation screen, radiation heat flow from the exterior can be isolated; and when the measurement system is in use, the Al<2>O<3> ceramic cover plate and the graphite gaskets with a weak eddy current effect are positioned in a region with severe magnetic field changes, while the cooling base, the cooling copper ring and the cooling copper column with an obvious eddy current effect are isolated from the region, so that the eddy current loss of the conduction cooling structure is suppressed by virtue of the conduction cooling structure layout.
Owner:BEIHANG UNIV

Linear coreless winding, preparation technology and linear permanent magnet motor with winding

The invention discloses a linear coreless winding. A wire of the winding is a strip-shaped copper sheet with the section long edge perpendicular to the movement direction of the linear motor, the strip-shaped copper sheets are concentrically wound to form a coil, and a plurality of coils are arranged adjacent to each other so as to form a linear winding structure; a concentrated winding can be adopted in the structure, and interference-free arrangement of end parts of the coils can be realized; or the coils are obtained through further processing, wherein the end parts of the coils are all located on one side of an effective part, and the coils are called an upper coil (100); the upper coil is overturned by 180 degrees along a geometric symmetry line to obtain lower coils (200, 300); the upper coil (100) and the lower coils (200, 300) are alternately arranged with each other to form the linear winding. The invention further discloses a preparation method of the winding and a linear permanent magnet motor with the winding. According to the linear coreless winding disclosed by the invention, an eddy current path is effectively cut off, the eddy current loss of the winding is inhibited, the copper cross section ratio in the air gap space is obviously improved, the power density of the motor is effectively improved, and the weight of the motor is reduced.
Owner:HUAZHONG UNIV OF SCI & TECH

Magnetic core, magnetic field shielding part and electronic photographic equipment with them

The present invention provides: (1) a magnetic coil in which magnetic particles 14 form an aggregate and the aggregate of the magnetic particles is disposed in a vessel 12 while the magnetic particles are keeping a particle state, (2) a magnetic field shield member for shielding magnetic field generated from a magnetic field generation member, the magnetic field shield member in which magnetic particles form an aggregate and the aggregate of the magnetic particles is disposed in a vessel 12 while the magnetic particles are keeping a particle state, and an electrophotographic apparatus using them.
Owner:FUJIFILM BUSINESS INNOVATION CORP

Dynamo electric machine

Disclosed is a dynamo electric machine wherein at least one coil end in the axial direction of a stator is bent toward the radial inside of the stator core and formed as a bent coil end, and eddy current loss caused by a magnetic field generated from the bent coil end is minimized. Torque of the rotor in the rotational direction is enhanced in such a dynamo electric machine by efficiently utilizing the magnetic field generated from the bent coil end. The rotor (2) includes a substantially cylindrical rotor core (3), and a counter end plate (4) which is fixed to the axial end face (31) of the rotor core (3) concentrically with the rotor core (3) while facing the bent coil end (81), wherein the counter end plate (4) principally comprises powder material produced by pressure molding the magnetic powder, i.e. the powder of a magnetic material, and a nonconductive state where an induction current produced by the magnetic field generated from the bent coil end (81) is regulated is brought about between the magnetic powders composing the powder material.
Owner:AISIN AW CO LTD

Multilayer filter

A multilayer filter includes dielectric layers, a first terminal, a second terminal, a first inductor, a second inductor, and first to fifth capacitors. In a stacking direction of the dielectric layers, at least one of a first air-core portion defined by the first inductor and a second air-core portion defined by the second inductor includes, in a region from the first inductor layer to the secondinductor layer, a region enabling magnetic flux to pass therethrough without being obstructed by the first to fifth capacitors and the third inductor.
Owner:MURATA MFG CO LTD

Flywheel pulse synchronous generator system with embedded permanent magnet rotor

The invention discloses a flywheel pulse synchronous generator system with an embedded permanent magnet rotor, belongs to the field of motors, and aims to solve the problems of low power density, lowenergy density and large volume weight of the system caused by long shafting and low rotating speed of an existing flywheel pulse generator set, of which the reliability is low and the cost is high.The system comprises an input inverter, an input motor, an embedded permanent magnet rotor synchronous motor, an output rectifier, an exciting current adjusting unit and an inertia flywheel, wherein the output end of the input inverter is connected with a leading-out wire of the input motor; the armature winding output end of the embedded permanent magnet rotor synchronous generator is connected with the alternating current input end of the output rectifier, and the armature winding output end of the embedded permanent magnet rotor synchronous generator is connected with the exciting current adjusting unit in parallel; a rotor of the input motor, a rotor of the embedded permanent magnet rotor synchronous generator and the inertia flywheel are coaxially connected. The system can be used asa high-capacity pulse power supply, and has a good application prospect in the fields of nuclear fusion test technology, plasma and electromagnetic emission technology and the like.
Owner:HARBIN INST OF TECH

Permanent magnet motor employing PCB winding

The invention discloses a permanent magnet motor employing a PCB winding. A PCB structure is adopted by the winding of the motor; in order to reduce eddy-current loss under the condition of a relatively high current of the winding of the motor, on one hand, a single wide winding conductor in a main magnetic field is converted into a plurality of narrow winding conductors in parallel; and on the other hand, a single wide end part conductor at one end part is at least converted into a plurality of narrow end part conductors in parallel; parallel branches of two parts are the same in number; and the parallel branches of the two parts are connected one by one in series. According to the permanent magnet motor employing the PCB winding, the eddy current loss of the PCB winding is greatly suppressed; additional moment generated by an eddy current is reduced; the motor output is improved; and the permanent magnet motor has important significance in energy conservation and improvement of the efficiency of the motor. A rigid PCB and a flexible PCB can be adopted by the PCB winding disclosed by the invention; and the permanent magnet motor can be applied to an axial-flux motor, a radial-flux motor, a rotary motor or a linear motor and the like.
Owner:SHENZHEN ACAD OF AEROSPACE TECH

Orthogonally magnetized controllable resistor based on direct current memory flux magnetism helping and adjusting

The invention discloses an orthogonally magnetized controllable resistor based on direct current memory flux magnetism helping and adjusting. The resistor comprises an alternating current working winding, an alternating current working iron core and a direct current memory flux orthogonal magnetism helping and adjusting device. The direct current memory flux orthogonal magnetism helping and adjusting device is composed of an orthogonal direct current working iron core, a direct current exciting winding, and an aluminum-nickel-cobalt permanent magnet with a direct current magnetic field memory function. Openings are formed in the two sides of the orthogonal direct current working iron core, a core column of the alternating current working iron core penetrates from the opening in one side of the orthogonal direct current working iron core, the aluminum-nickel-cobalt permanent magnet is embedded into the opening in the other side of the orthogonal direct current working iron core, the direct current exciting winding is wound around the aluminum-nickel-cobalt permanent magnet, and the alternating current working winding is wound around the alternating current working iron core. The resistor is simple in structure, the reactance is linear, and can be smoothly adjusted within a wide range, electromagnetic loading of the direct current exciting winding is greatly relieved through aluminum-nickel-cobalt magnetism helping and adjusting, and the running efficiency of a system is improved.
Owner:SUZHOU WUBIAN ELECTRICAL TECH CO LTD

High-magnetic-induction high-frequency nanocrystalline soft magnetic alloy and preparation method thereof

M is one or more of Nb, Mo, V, Mn and Cr, and the molar percentage content of the elements is as follows: b is more than or equal to 6 and less than or equal to 15, c is more than or equal to 5 and less than or equal to 12, d is more than or equal to 0.5 and less than or equal to 3, e is more than or equal to 0.5 and less than or equal to 1.5, f is more than or equal to 0.5 and less than or equal to 3, and the balance of Fe and impurities. The difference value between the induced anisotropy value and the average magnetocrystalline anisotropy value is 0.1-1J / m < 3 >. The magnetically soft alloy has relatively high magnetic conductivity and relatively low magnetic loss under high frequency. The invention further discloses a preparation method of the high-magnetic-induction and high-frequency nanocrystalline soft magnetic alloy. The induced anisotropy value (Ku) and the average magnetocrystalline anisotropy value (lt; k1gt; K1gt; therefore, the high-frequency soft magnetic performance is improved.
Owner:NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI

MnZn (manganese and zinc) ferrite material with low power consumption under conditions of high magnetic flux and high frequency and preparation method thereof

The invention discloses a MnZn (manganese and zinc) ferrite material with low power consumption under conditions of high magnetic flux and high frequency and a preparation method thereof, and belongs to the technical field of preparation of soft magnetic ferrite. The MnZn ferrite material is prepared from the following main components of 53.5 to 55mol% of Fe2O3 (iron oxide), 5.5 to 7.0mol% of ZnO (zinc oxide), and the balance of MnO (manganese oxide); on the basis of total weight of the main component, the auxiliary components include 0.1 to 0.15wt% of CaCO3 (calcium carbonate), 0.003 to 0.005wt% of SiO2 (silicon dioxide), 0.03 to 0.05wt% of ZrO2 (zirconium oxide), 0.3 to 0.4wt% of Co2O3 (cobalt dioxide), 0.1 to 0.2wt% of TiO2 (titanium dioxide), and 0.006 to 0.01wt% of NaO2 (sodium dioxide). The MnZn ferrite material has the advantages that the reasonable main components and auxiliary components are adopted, especially the trace additives of Na (sodium) and the like can reach regulating and control function on the microscopic structure of the sintering material, and the characteristics of low oxygen content, strong densifying, and lower sintering temperature no higher than 1170 DEG C in the sintering heating phase are combined, so as to obtain the microscopic structure with fine and uniform grain particles and higher density, thereby greatly reducing the power consumption under the conditions of high magnetic flux and high frequency.
Owner:NANJING NEW CONDA MAGNETIC INDAL

Aluminium alloy armored parallel assignment intelligent composite power cable and manufacture method thereof

The invention discloses an aluminium alloy armored parallel assignment intelligent composite power cable which comprises three power cables in triangle cross section mutual parallel assignment. A temperature-sensitive fiber cable is provided at a center of geometry space formed by the assignment of the three cables and is parallel with the power cables. An aluminium alloy armored protecting pipe is sleeved on an external part of the three power cables in a sealing way and is in a bellows shape. The invention also discloses a manufacture method of the above aluminium alloy armored parallel assignment intelligent composite power cable, and the method is simple and easy in enforcement. The intelligent composite power cable can monitor work temperature of the cable in real time and in an intelligent way. The cable can be buried into surface soil with waterproof, ant prevention, mouse prevention and corrosion resistance. Eddy current loss is inhibited, surrounding electric field intensity is reduced, electromagnetic radiation and electrochemical corrosion are reduced, and a safety operation electrical condition of power transmission is satisfied. The cable has a wide application scope.
Owner:莫凡

Bulk acoustic wave magnetic field sensor based on magnetoelectric coupling and optimization method thereof

The invention discloses a magnetoelectric coupling-based bulk acoustic wave magnetic field sensor and an optimization method thereof. The magnetoelectric coupling-based bulk acoustic wave magnetic field sensor structurally comprises a magnetic composite film and a bulk acoustic wave resonator, the magnetic composite thin film comprises a FeGaB magnetostrictive thin film and an Al2O3 thin film inserted into the FeGaB magnetostrictive thin film; the bulk acoustic wave resonator comprises a Mo electrode film, an AIN piezoelectric film and a silicon substrate which are arranged in sequence. According to the bulk acoustic wave magnetic field sensor, the composite magnetic film is adopted, eddy current loss is restrained, and the soft magnetic characteristic is enhanced; meanwhile, a piezomagnetic phase / piezoelectric phase double-layer structure design is adopted, so that the magnetoelectric (ME) coupling efficiency is improved; the resonance is utilized to enhance the ME coupling effect, and the thickness of the piezoelectric phase / piezomagnetic phase and the electrode layer is designed, so that the sensor works at the ferromagnetic resonance frequency of the composite film, and the energy conversion efficiency is further improved. Therefore, the performance optimization method of the bulk acoustic wave magnetoelectric coupling magnetic field sensor is obtained.
Owner:SOUTHWEAT UNIV OF SCI & TECH

A Broadband and Low Eddy Current Loss Artificial Conductor

The invention relates to an artificial conductor with broadband and low eddy current loss, which belongs to the technical field of radio frequency devices and integrated circuits. The artificial conductor is a metal thin film layer / (ferromagnetic thin film layer / metal thin film layer) formed by alternate lamination of metal thin film layers and ferromagnetic thin film layers n The periodic multilayer film structure, wherein, the material of the 1st~n / 2 ferromagnetic thin film layer is ferromagnetic material A, and the material of (n / 2+1)~n ferromagnetic thin film layer is ferromagnetic material b. The invention adopts two different ferromagnetic materials as the ferromagnetic thin film layer to form an asymmetric structure, so that the artificial conductor can suppress eddy current loss in a wider frequency band. The artificial conductor of the present invention considers suppressing the eddy current loss at a lower frequency, and can also have an eddy current suppression effect in a wider frequency range, which solves the problem of narrow suppression frequency band under low frequency compensation, and has great advantages in radio frequency devices and integrated circuits. Great application prospects.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Embedded permanent magnet rotor flywheel pulse synchronous generator system

The invention discloses a flywheel pulse synchronous generator system with an embedded permanent magnet rotor, belongs to the field of motors, and aims to solve the problems of low power density, lowenergy density and large volume weight of the system caused by long shafting and low rotating speed of an existing flywheel pulse generator set, of which the reliability is low and the cost is high.The system comprises an input inverter, an input motor, an embedded permanent magnet rotor synchronous motor, an output rectifier, an exciting current adjusting unit and an inertia flywheel, wherein the output end of the input inverter is connected with a leading-out wire of the input motor; the armature winding output end of the embedded permanent magnet rotor synchronous generator is connected with the alternating current input end of the output rectifier, and the armature winding output end of the embedded permanent magnet rotor synchronous generator is connected with the exciting current adjusting unit in parallel; a rotor of the input motor, a rotor of the embedded permanent magnet rotor synchronous generator and the inertia flywheel are coaxially connected. The system can be used asa high-capacity pulse power supply, and has a good application prospect in the fields of nuclear fusion test technology, plasma and electromagnetic emission technology and the like.
Owner:HARBIN INST OF TECH

A three-dimensional porous flower-like cobalt/carbon nanocomposite electromagnetic wave absorbing material and its preparation method

The invention relates to a three-dimensional porous flower-like structure cobalt / carbon nano-composite electromagnetic wave absorbing material. Carbon in the electromagnetic wave absorbing material forms a three-dimensional skeleton in a flower-like structure, and carbon coated cobalt particles are uniformly distributed on a carbon matrix. The preparation method comprises the following steps: 1) serving divalent inorganic cobalt salt as a precursor of cobalt hydroxide, and dissolving the divalent inorganic cobalt salt and surfactant into a solvent according to a certain mass ratio; carrying out reaction under an enclosed condition, and after reaction, carrying out washing and drying on the product to obtain the cobalt hydroxide; carrying out calcination treatment on the prepared cobalt hydroxide to obtain cobaltosic oxide powders; and 2) mixing the cobaltosic oxide powders obtained in the step 1) with a carbon source, and carrying out reaction under an enclosed condition to obtain thethree-dimensional porous flower-like structure cobalt / carbon nano-composite electromagnetic wave absorbing material. The prepared electromagnetic wave absorbing material is high in saturation magnetization, high in coercive force, light in weigh and high in oxidation resistance and has an excellent electromagnetic wave absorption performance.
Owner:SHANDONG UNIV

Interior magnet rotary electric machine

The invention provides an interior magnet rotary electric machine. This interior magnet rotary electric machine (1) is provided with a rotor (2) that has a rotor core (11) having two sets of permanent magnets (12, 13) embedded therein, a stator (3) that is disposed facing the rotor (2), and a fiber strengthened plastic tube (4) which sleeves and is fixed at the rotor core (11).
Owner:KOBE STEEL LTD

A non-contact power transmission system for vertical drilling system

The invention discloses a non-contact electric energy transmission system for a vertical drilling system. The non-contact electric energy transmission system comprises a transformer, a series resonant inverter circuit, a rectification output circuit and an inverter control circuit, wherein the transformer is a separate transformer which comprises primary magnetic cores and secondary magnetic cores which are separated from one another; a plurality of grooves which are formed along the axis are formed in the outer circular surface of a power main shaft of the drilling system and in the inner circular surface of a hole straightening loop respectively; the primary magnetic cores are arranged in the grooves of the power main shaft; the secondary magnetic cores are arranged in the grooves of the hole straightening loop; the central angle theta formed by the circular arcs on the surfaces of the secondary magnetic cores opposite to the axis of the power main shaft meets a certain relationship, so that the magnetic resistance between the primary magnetic cores and the secondary magnetic cores is constant and is not affected by rotary motion; the phase difference between the voltage and the current is calculated by detecting an output voltage signal and an output current signal of the inverter circuit; the system is kept to work in a resonant state by adjusting the switching frequency, so that the hardware circuit is simplified and the flexibility for phase detection is improved.
Owner:BC P INC CHINA NAT PETROLEUM CORP +1

Inverter, inverter control method and motor system

The invention relates to an inverter, an inverter control method and a motor system. The inverter comprises a control device and a single-phase control circuit, the single-phase control circuit comprises more than two bridge arm circuits, and each bridge arm circuit comprises an upper bridge arm control switch and a lower bridge arm control switch. One single-phase control circuit in the inverter comprises more than two bridge arm circuits which are connected in parallel, the plurality of bridge arm circuits can be conducted in a staggered manner, the switching times of each control switch in each bridge arm circuit are shared, the equivalent switching frequency of the inverter is improved, the upper limit of the switching frequency is improved, the actual switching frequency of a single control switch of the inverter is in a low range, large temperature rise is not caused, the effect of inhibiting the eddy current loss of a rotor is achieved, high-efficiency and ultra-high-speed operation control of a motor is achieved, and the use reliability of motor driving is improved.
Owner:GREE ELECTRIC APPLIANCES INC
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