232results about How to "Improve the withstand voltage level" patented technology

This invention provides one transducer paint enamel wire production method, which uses copper bar as materials to process the enamel wire through pressing and shaping and painting or product processing, wherein, the production adopts pressing pushing feeding and wheel groove friction pressing with temperature through module hole pressing to form once shaping process to substitute the traditional process. The process saves the annealing step and comprises the steps: copper transmission correction; pressing by one time and cooling anti-oxidation; soft bare wire receiving wires; painting and drying wires; paint baking; product receiving line.

The invention discloses a vertical double-diffusion metal oxide semiconductor field effect transistor (MOSFET), which comprises a metallization drain 1, an N<+> substrate 2, an N<-> drift region 3, a deep P body region 5, an N type heavy doping source region 6, a P type heavy doping region 7, an N type buried layer channel 8, a P type epitaxial layer 9, a gate oxidation layer 10, a polysilicon gate electrode 11 and a metallization source 12. When the vertical double-diffusion MOSFET is switched on, the switch-on resistance of a device is greatly reduced through the common electricity conducting mechanism of two channels; and when the vertical double-diffusion MOSFET is switched off, electric fields of the channels are shielded through a P+N junction barrier, so that a higher voltage-resisting level of more than 1,000V is realized.

The invention discloses a unit by-path apparatus for a unit cascade high voltage frequency converter, and control method thereof, wherein a by-path centralized control board being connected with a main circuit control board and an isolation transformer separately; the other end of the isolation transformer being connected with a by-pass contactor which is connected with an unit output. The by-pass apparatus is composed of a main circuit control board, a by-path centralized control board, an isolation transformer, and a by-path contactor. The method includes the steps of transferring a unit fault signal to the main circuit control board firstly; cutting off the main circuit current; thirdly, the by-path centralized control board transmitting a by-path contactor motion completion signal to the main circuit control board; fourthly, the main circuit control board transmitting IGBT control signal based on the acquisition motor backemf. The apparatus of the invention has a simple structure, and can cut off the failure unit by path completely reliably, eliminate the error and refused onstate of other type by-pass systems, and assure the safe and reliable motion of the whole by-pass method.

The invention discloses a three-layer co-extrusion PVC-M tubular product for coal mine, characterized in that the tubular product comprises an antistatic inner layer, an antistatic outer layer and a PVC-M interlayer, wherein the antistatic inner and outer layer compositions comprise the following ingredients: 100 weight parts of PVC resin, 0.8-1.2 weight parts of heat stabilizer, 4-8 weight parts of toughening agent, 1.3-2.0 weight parts of lubricating agent, 5-10 weight parts of flow modifier, and 6 weight parts of nano conductive carbon black; the PVC-M interlayer composition comprises the following ingredients: 100 weight parts of PVC resin, 1.0-1.5 weight parts of heat stabilizer, 10-15 weight parts of toughening agent, 2.1-3.5 weight parts of lubricating agent, and 0-5 weight parts of filling agent. According to the invention, the composition of the tubular product has high strength, the shock resistance of the tubular product can be comparable to that of polyethylene antistatic tubular products for coal mine, the modulus reaches to 2231MPa, the tensile strength reaches to 46.3Mpa, the impact strength of the simple-supported beam reaches to 97.6Mpa, the mechanical property shows toughness and balance and permanent antistatic property, thus the requirements of the tubular product for coal mine are satisfied.

The invention relates to insulating crosslinking polyethylene for a winding cable, which is characterized by comprising the following components by weight portion: 100 portions of low density polyethylene (LDPE), 35 to 55 portions of ethylene-vinyl acetate copolymer (EVA), 30 to 45 portions of polyisobutylene (PISOB) or butyl rubber (iiR), and 1.5 to 2.2 portions of peroxide cross-linking agent; and the insulating crosslinking polyethylene is prepared from the components through crosslinking. The insulating crosslinking polyethylene not only keeps the excellent electric property of the crosslinking polyethylene, in particular to the low electric loss of the crosslinking polyethylene, but also improves the softness of the crosslinking polyethylene, can satisfy the requirements on winding and inserting the winding cable, and improves the low temperature resistance of an insulating material. The insulating crosslinking polyethylene is not cracked by low-temperature impact at a temperature of 50 DEG C below zero in a test, can satisfy the mounting of cables in an environment at a temperature of not less than 25 DEG C below zero, and has the bending times of more than 1,000 to 1,100 times (according to the test condition of GB/T12706.2-2002), thus the insulating crosslinking polyethylene is particularly suitable for the insulation of winding wires of a high-voltage motor or a transformer for wind power generation and hydroelectric power generation.

Provided is a high-voltage transmission convertor station overvoltage protection device. By connecting a protection circuit to an AC side serial-connection protection circuit and a thyristor valve bank in parallel, the damage caused by overvoltage in a transmission line is restrained, the energy produced by faults in the transmission line at the front stage and the rear stage of a convertor station is rapidly absorbed, the normal running of the transmission line is protected, and fault ride-through is achieved.

The invention discloses an ultraviolet photodiode based on NiO/Ga2O3, comprising a top electrode and a bottom electrode, wherein A P-type crystal NiO film, an I-type crystal beta-Ga2O3 film, and an N-type single crystal beta-Ga2O3 substrate are sequentially disposed between the two electrodes from the top electrode to the bottom electrode. The invention also discloses a preparation method of an ultraviolet photodiode based on NiO/Ga2O3. The invention solves the problem that the Ga2O3-based pn junction ultraviolet photodiode cannot be prepared due to the lack of p-type Ga2O3 material in the prior art.

The invention discloses a non-isolated grid-connected converter, an air-conditioning system and a converter control method, which belong to the field of efficient grid-connected converters, and are designed for solving the problems of large size of the existing devices and the like. The non-isolated grid-connected converter at least comprises a rectifying and inverting unit, and has the bidirectional functions of rectification and inversion. The air-conditioning system comprises the non-isolated grid-connected converter. The control method based on the non-isolated grid-connected converter comprises a rectification mode. The non-isolated grid-connected converter adopts a bidirectional DC/AC converter to realize rectification, PFC and grid-connection functions, omits an isolation transformer, reduces number of devices, and is small in size. The air-conditioning system provided by the invention is small in size and higher in energy efficiency. The control method of the non-isolated grid-connected converter achieves the effects of low leakage current and high grid access current, can increase the voltage withstand level through rectification, reduces AC harmonic voltage and current, and increases power factors.

The invention relates to the field of cables, and in particular relates to a low-smoke halogen-free flame-retardant cable and a manufacturing method thereof. The low-smoke halogen-free flame-retardant cable comprises a conductive core, wherein an insulating layer is arranged outside the conductive core and has a three-layer structure; the outer layer is made of low-smoke halogen-free flame-retardant polyolefin; and the middle layer and the inner layer are made of cross-linked polyolefin. The insulating layer of the cable is designed into an asymmetrical three-layer structure, so that the insulating layer has low-smoke halogen-free flame retardancy, excellent tensile strength, breaking elongation and other comprehensive mechanical properties, and the insulating layer of the cable has high voltage-resistant level.

The invention provides a method for manufacturing calcined type fireproof mica tape. The method includes the steps of preparing tackiness agents, preparing tackiness agent solutions, coating glass fabric with the tackiness agent solutions, gluing mica paper and the glass fabric, and carrying out baking in a dryer. The method is characterized in that baking is carried out within three periods at different temperatures. The mica tape produced with the method is free of falling, powder falling, foam generating and reverse gluing and good in breathability, the mica paper is not separated from the glass fabric after the mica tape is soaked by methylbenzene for seventy-two hours, and the temperature resistant level and the voltage withstand level of the mica tape are higher; in addition, the rate of finished products is quite high, flexibility is excellent, and various properties are more stable.

The invention discloses a method for measuring ground potential by use of a multilayer sensor structure, and also discloses a multilayer sensor structure. The multilayer sensor structure comprises four copper-sheet electrodes, the four copper-sheet electrodes are successively arranged in a parallel mode and are successively a copper-sheet electrode I, a copper-sheet electrode II, a copper-sheet electrode III and a copper-sheet electrode IV from top to bottom, the copper-sheet electrode I and the copper-sheet electrode II have the same specifications, the copper-sheet electrode III and the copper-sheet electrode IV have the same specifications, the specifications of the copper-sheet electrode I and the copper-sheet electrode II are smaller than the specifications of the copper-sheet electrode III and the copper-sheet electrode IV, and the four copper-sheet electrodes are sealed in an epoxy resin insulation material. The method provided by the invention overcomes disadvantages of a conventional measurement method, can directly obtain the ground potential of a detected point, realizes real-time monitoring of ground potential values, and is convenient to use and is reliable in measurement result.

The invention discloses a CuAlO2/Ga2O3 ultraviolet photodiode, comprising a top electrode and a bottom electrode, wherein a P-type crystal CuAlO2 film, an I-type beta-Ga2O3 film, and an N-type singlecrystal beta-Ga2O3 substrate are sequentially disposed between the two electrodes from the top electrode to the bottom electrode. The invention also discloses a preparation method of a CuAlO2/Ga2O3 ultraviolet photoelectric diode. The invention solves the problem that the Ga2O3-based PIN ultraviolet photoelectric diode cannot be prepared due to the shortage of p-type Ga2O3 material in the prior art.

The invention relates to the technical field of power systems, and specifically relates to a power electronic transformer based on virtual grid flux orientation. The invention discloses a power electronic transformer based on virtual grid flux orientation, comprising a rectifier, a middle isolation level, an inverter, and a control board. The alternating-current side of the rectifier is connected with a grid, and the direct-current side of the rectifier is connected with a high-voltage port of the middle isolation level. The direct-current side of the inverter is connected with a low-voltage port of the middle isolation level, and the alternating-current side of the inverter is connected with a transmission line or load. The control board is connected with the rectifier, the middle isolation level and the inverter. The control board generates pulse signals, and controls on-off of power switching devices of the rectifier, the middle isolation level and the inverter. The control board adopts a directional control strategy based on virtual flux to reduce the impact of grid fluctuation on the system.

The invention discloses an air kinetic energy ejection launcher for a spacecraft. The air kinetic energy ejection launcher for the spacecraft comprises an air inflation mechanism and a high pressure air spherical tank. The air inflation mechanism is communicated with the high pressure air spherical tank and used for providing vaporized gas for the high pressure air spherical tank, a blind plate cover with the gear shaped inner edge is installed on the opening in the top of the high pressure air spherical tank, a blind plate with the gear shaped outer edge is installed in the blind plate cover, the blind plate cover is connected with an electromagnetic drive device, after the electromagnetic drive device detects that the gas in the high pressure air spherical tank reaches the preset value, an operator operates the electromagnetic drive device to drive the blind plate cover to rotate by one gear, an ejection guide rail is also arranged on the upper end of the blind plate cover, the track cross-section shape of the ejection guide rail is matched with the shape of the blind plate, so that the blind plate can conduct ejection movements in the ejection guide rail under the push of the air pressure, the extending part of the upper end of the ejection guide rail is provided with a guide cylinder, and the spacecraft is installed above the blind plate. The device can reduce more than 90% of the void volume and launch weight, the launch speed of the spacecraft can be higher than 30,000-300,000 m/s, and the cost is low.

The invention provides an earthing switch device which can be switched between a separating brake state and an on-position state. The earthing switch device comprises an underframe (1), at least one pair of fixed contacts (2), at least one pair of movable contacts (3), a main shaft (4), a connecting lever part (7) and a shield part (6), and the main shaft (4) is arranged on the underframe (1) in a rotating mode. The connecting lever part (7) is used for fixed installation of the movable contacts (3) on the main shaft (4). The shape and/or arrangement of the shield part (6) allows the earthing switch device to shield the connecting lever part (7) under the separating brake state, opposite to the static contacts (2). The earthing switch device can at least eliminate top electric field between the fixed contacts (2) and the connecting lever part (7), and improves evenness of electric field of the earthing switch device.