57 results about "Resistive loss" patented technology

The invention relates to the technical field of photovoltaic power generation, and discloses a solar cell and a preparation method thereof, and a photovoltaic module. The invention provides a solar cell. The doping concentration of a boron element in a first doped polycrystalline silicon layer is 8 * 10 < 19 > atoms / cm < 3 > to 8 * 10 < 20 > atoms / cm < 3 >; a second tunneling oxide layer, wherein the second tunneling oxide layer is arranged in the second region of the silicon substrate; and the second doped polycrystalline silicon layer is arranged on one side, far away from the silicon substrate, of the second tunneling oxide layer. Therefore, the high-doping-amount contact structure of the backlight surface of the solar cell has relatively high passivation quality and good contact characteristics, and carrier recombination and resistance loss can be reduced, so that the photoelectric conversion efficiency of the solar cell is improved.

The invention discloses an electromagnetic wave absorbing material CoFe2O4 / ZnO-RGO with a ternary heterostructure as well as a preparation method and application of the electromagnetic wave absorbing material CoFe2O4 / ZnO-RGO, and belongs to the technical field of electromagnetic wave absorption. According to the material, a novel heterostructure with a multi-scale interface and a three-dimensional conductive network is constructed by compounding magnetic loss type CoFe2O4, dielectric loss type ZnO nanorods and resistance loss type RGO. Wherein the ZnO nanorod not only serves as a dielectric loss body, but also effectively enhances the structural anisotropy and the interface polarization effect of the material, and cooperates with the magnetic loss of CoFe2O4 and the resistance loss of RGO to jointly optimize impedance matching and improve the electromagnetic attenuation capability, so that the material shows excellent wave-absorbing performance under various thickness and even ultrathin conditions. The material source is wide, the cost is low, the preparation process is green, simple and convenient, the material is suitable for large-scale production, and an effective material solution is provided for electromagnetic wave absorption application in the national defense and civil fields.

The embodiment of the invention provides a back contact crystalline silicon solar cell and a back contact photovoltaic module, the back contact crystalline silicon solar cell comprises a crystalline silicon substrate, the back surface of the crystalline silicon substrate is alternately provided with a first region and a second region, and the first region comprises a current collection region and a lamination region; in the collector region, the back surface of the crystalline silicon substrate is sequentially provided with a doped internal expansion layer, a first interface passivation layer, an N-type doped polycrystalline silicon layer, a transparent conductive oxide layer and a first back electrode, and a plurality of protruding structures are distributed on the surface of the N-type doped polycrystalline silicon layer. The contact area between the protruding structure and the first back electrode through the transparent conductive oxide layer is increased, so that the transmission resistance loss of carriers transported from the crystalline silicon substrate to the first back electrode is reduced, and the photoelectric conversion efficiency of the back contact crystalline silicon solar cell is improved.

The invention relates to the technical field of wires and cables, and discloses a high-efficiency energy-saving wire and cable, which comprises a conductor layer, a first insulating layer, a heat dissipation layer, a shielding layer, a second insulating layer and a protective layer which are sequentially arranged from inside to outside, resistance loss is reduced through the conductor layer, heat is dissipated in time through the heat dissipation layer, electromagnetic radiation loss is reduced through the shielding layer, the insulation effect is guaranteed through the first insulation layer and the second insulation layer, the overall structure of the cable is protected through the protection layer, the service life is prolonged, and therefore efficient and energy-saving operation of the cable is achieved.

A wafer structure is disclosed comprising a top silicon layer with a polished surface, an oxide layer selectively removed in defined regions, and a bottom silicon layer. Selective oxide removal improves dicing, prevents small molecule ingress, and enhances MEMS device release and performance. The invention addresses challenges of conventional silicon-on-insulator (SOI) wafers, including jagged edges, particle generation during stealth dicing, slow and uncontrolled under-etch rates, and high resistive losses in radio frequency (RF) applications due to parasitic surface conduction. Patterning the oxide layer enables precise MEMS structure release, reduces die size, and improves RF isolation. The wafer structure is suitable for high-speed electronics, RF analog circuits, and MEMS devices such as resonators, accelerometers, and waveguides, offering improved manufacturability and device reliability.

The invention discloses a wide bandgap semiconductor device, which can be used in the field of semiconductors, and comprises a P-type column region, an N-type column region, a P-type buried layer, a P-type connecting layer, a grid electrode and a source electrode, wherein the P-type column regions and the N-type column regions are alternately arranged along a first direction; the P-type column region, the P-type buried layer, the P-type connecting layer and the source electrode are arranged along a second direction, and the P-type connecting layer is in contact with the source electrode; the first direction is perpendicular to the second direction; the N-type column region, the grid electrode and the source electrode are arranged along a second direction; the P-type buried layers and the P-type connecting layers are discontinuously distributed in a third direction, any P-type buried layer is electrically connected with at least one P-type connecting layer in a three-dimensional space, and any P-type column region is electrically connected with at least one P-type buried layer in the three-dimensional space; the third direction is perpendicular to the first direction and the second direction. Therefore, an electrical connection path of the P-type column region, the P-type buried layer, the P-type connection layer and the source electrode is constructed, and the dynamic resistance loss of the device is effectively reduced.

The invention discloses a low-profile band-pass frequency selective wave-absorbing surface with broadband wave absorption. The low-profile band-pass frequency selective wave-absorbing surface comprises a resistance loss layer, an air layer and a band-pass FSS transmission layer in sequence from top to bottom, the resistance loss layer comprises a first dielectric substrate, a central metal sheet is printed at the center of the upper surface of the first dielectric substrate, an etching groove is etched in the central metal sheet, a parallel LC resonance circuit is formed through the etching groove, the periphery of the central metal sheet is connected with metal bridge arms which are symmetrically distributed in a central rotation mode and extend outwards, and the metal bridge arms are connected with the first dielectric substrate. The tail end of each metal bridge arm is connected with a circular metal sheet which takes the midpoint of the tail end of the metal bridge arm as a circle center, and lumped resistors are loaded on the metal bridge arms; through the single resistance loss layer, loading of the lumped resistor and special slotting of the resistance loss layer, broadband wave absorption with a band-pass window can be realized by using a two-dimensional structure, and the broadband wave absorption device has the characteristics of low profile, easy processing, flexible regulation and control and the like.

A broadband low-loss waveguide coaxial converter comprises a waveguide lower cavity, a waveguide groove is formed in the middle of the upper surface of the waveguide lower cavity and extends to one side in the waveguide transmission direction, a metal tuning column is arranged at the inner bottom of the waveguide groove, a metal shielding unit is arranged on the periphery of the waveguide groove, and a supporting boss is arranged on the periphery of the metal shielding unit. The bottom surface of the waveguide groove is lower than the upper end of the metal tuning column, the metal shielding unit and the upper surface of the supporting boss; the waveguide upper cover plate covers the supporting boss and is fixedly connected to the supporting boss, a circular hole is formed in the waveguide upper cover plate, a coaxial interface matched with the inner diameter structure of the circular hole is coaxially formed in the circular hole, and an air circular cavity is formed in the lower portion in the circular hole. The waveguide cavity adopts upper and lower split processing, the waveguide lower cavity is not in direct contact with the metal surface of the waveguide upper cover plate, and the metal shielding columns are arranged on the two sides of the waveguide groove of the waveguide lower cavity to realize normal electromagnetic signal transmission without leakage, so that resistive loss caused by metal surface contact is avoided, and insertion loss is effectively reduced.

According to the high-electron-mobility transistor and the preparation method thereof, the graphene field plate is used for replacing a traditional metal field plate, compared with a metal material, the carrier mobility of the graphene material is higher, the resistance of the graphene material is far lower than that of the metal material in a high-frequency state, the resistance loss of a device can be reduced, and the performance of the device is improved. The metal field plate has a certain requirement on the thickness of a dielectric layer below the field plate due to the relationship between surface roughness and stress, and graphene is a two-dimensional material and can be in close contact with a dielectric without defects, so that the thickness of the dielectric layer below the field plate can be thinner, and the gate-drain capacitance is reduced; a fringe electric field is prevented from being introduced into the side wall of the field plate, so that parasitic components of gate-drain capacitance can be reduced.

The utility model relates to the technical field of copper conductors, and discloses a cable copper conductor of a liquid cooling over-charge charging pile, which comprises a copper conductor, a control wire core is fixedly arranged above the copper conductor, a signal wire core is fixedly arranged below the copper conductor, and a filling layer is fixedly arranged on the outer layers of the copper conductor, the control wire core and the signal wire core. A cooling pipeline is fixedly installed on the outer layer of the filling layer, a buffer layer is fixedly installed on the outer layer of the cooling pipeline, and a rubber sheath layer is fixedly arranged on the outer side of the wrapping layer. The copper conductor and the cooling water pipe of the cable of the liquid-cooled over-charging pile use cooling liquid to cool the copper conductor, take away heat generated by resistance loss of the cable during current transmission, improve current transmission efficiency, realize ultra-fast charging, and effectively resist some external electromagnetic interference by adopting the copper wire shielding braided layer as the wrapping layer. And in the use process, the electromagnetic interference problem of external electromagnetism on power-on transmission is effectively prevented.

The invention discloses an energy-saving high-voltage switch cabinet and a control method, and relates to the technical field of energy conservation of high-voltage switch cabinets, the energy-saving high-voltage switch cabinet comprises a high-voltage switch cabinet body, a multi-mode busbar monitoring unit and an active electromagnetic compensation unit, the multi-mode busbar monitoring unit is installed on the periphery of a plurality of busbars of the high-voltage switch cabinet body, and the active electromagnetic compensation unit is installed on the periphery of the multi-mode busbar monitoring unit. The temperature and non-contact pressure fluctuation of a plurality of busbars are respectively monitored, and the temperature and non-contact pressure fluctuation of the busbars are monitored in real time, so that the resistance change of the busbars can be accurately predicted, electromagnetic compensation is carried out in time when the resistance is increased, and the loss in the electric energy transmission process is reduced. The active electromagnetic compensation can dynamically adjust the compensation magnetic field, ensures the stability of the busbar contact point resistance, reduces the electric arc and fault caused by poor contact, and improves the stability and reliability of the system. By reducing the resistance loss, the overall energy consumption of the switch cabinet is reduced, energy conservation and emission reduction are facilitated, and the switch cabinet conforms to the green and environment-friendly development trend.

This invention provides a photovoltaic module and a photovoltaic system, relating to the field of photovoltaic technology. The photovoltaic module includes: a conductive backsheet and back contact cells disposed on the conductive backsheet; the back contact cells include: a plurality of current collector grid lines; the conductive backsheet includes: a conductive layer and an insulating layer located between the conductive layer and the back contact cells; the conductive layer includes: a plurality of finger-shaped conductive structures extending along a second direction, and insulating gaps located between adjacent finger-shaped conductive structures; through-holes are formed in the insulating layer, and a portion of the finger-shaped conductive structure at the through-hole is electrically connected to the corresponding current collector grid lines; in the region of the conductive layer corresponding to a back contact cell, the number of finger-shaped conductive structures is a first quantity; the ratio of the width of the insulating gap to the first quantity is 18 to 125. This photovoltaic module exhibits strong current collection capability and low resistance loss, low manufacturing cost, high yield, low short-circuit risk, low probability of waste wire breakage, and high waste removal efficiency.

The utility model discloses a low-temperature-rise power capacitor, and belongs to the technical field of power capacitor manufacturing. According to the low-temperature-rise power capacitor provided by the utility model, the heat dissipation efficiency of the power capacitor is improved in a leap-over manner through the optimization of a heat conduction path, and specifically, the heat dissipation efficiency of the power capacitor is improved through the covering design of the first heat conduction sheet, the second heat conduction sheet, the third heat conduction sheet and the fourth heat conduction sheet on the conductor; the heat generated by the conductor due to resistance loss and the heat generated by the insulation medium loss are quickly conducted to the first heat-conducting fin, the second heat-conducting fin, the third heat-conducting fin and the fourth heat-conducting fin, so that quick heat dissipation is realized; the fifth heat-conducting fin covers the third side wall and the fourth side wall of the core, so that a surrounding heat-conducting structure for the core is formed, heat generated by a plurality of layers of elements in the core due to loss of an insulating medium can be efficiently collected, and the problem that heat of the core of a traditional capacitor can only be singly conducted through a shell is solved; and the dredging efficiency of the loss heat of the insulating medium is improved.

The present invention provides a solar cell, a production method, and a solar cell assembly, relating to the field of photovoltaic technology. The solar cell comprises: an emitter layer, an N-type silicon substrate, a back surface field layer, and a metal-doped amorphous silicon layer, which are stacked in sequence; the atomic percentage of hydrogen atoms in the metal-doped amorphous silicon layer is w, with 20% ≥ w ≥ 5%; the emitter layer is located on the light-facing surface of the N-type silicon substrate; the front electrode is located on the light-facing surface of the emitter layer; and the back metal electrode is located on the backlight side of the metal-doped amorphous silicon layer. The metal-doped amorphous silicon layer enhances its barrier effect on minority carriers while selectively allowing majority carriers to pass through, improving carrier selectivity, reducing interfacial recombination between the back metal electrode and the back surface field layer, reducing resistance loss, and providing excellent electrical conductivity. The abundant hydrogen atoms in the metal-doped amorphous silicon layer effectively passivate internal defects and interfacial defects in the N-type silicon substrate and the back surface field layer, reducing interfacial recombination between the back metal electrode and the back surface field layer.

The utility model relates to the technical field of keyboards, in particular to a composite device for keyboard contacts, which comprises a contact base body and a keyboard, alloy materials are inlaid on a contact working face at the top of the contact base body and are copper-based alloy, an installation groove is arranged on the upper surface of the keyboard, and the installation groove is provided with a through hole. Clamping grooves are formed in the front and rear groove walls of the mounting groove; an integrally-formed contact surface layer is arranged on the alloy material, the contact surface layer is conical, the longitudinal section of the contact surface layer is in an isosceles trapezoid shape, the contact surface layer and the alloy material are integrally formed, and arc-shaped elastic pieces used for being clamped into the clamping grooves are arranged on the front surface and the rear surface of the contact base body. The side wall of the contact base body is provided with an integrally formed positioning mark. According to the keyboard contact compounding device, high-conductivity materials are inlaid in the working face, resistance loss is reduced, sensitivity is improved, a wear-resistant process is adopted, the service cycle is prolonged, materials are inlaid in the key face, the using amount of precious metal is reduced, and cost is reduced.

The utility model discloses an energy-saving medium-voltage power cable for a power system. The energy-saving medium-voltage power cable comprises a cable core, the cable comprises a cable core, a plurality of annularly distributed wire cores are arranged in the cable core, each wire core is composed of a conductor, a co-extrusion insulating layer and a metal shielding layer, a filling layer is arranged in a gap between the cable core and the wire cores, a wrapping layer is arranged outside the cable core, an isolating layer is arranged outside the wrapping layer, an armor layer is arranged outside the isolating layer, and a sheath layer is arranged outside the armor layer. The armor layer is composed of a buffer layer, a compression-resistant layer and an enhancement layer, an outer sheath is arranged outside the armor layer, and the scheme solves the problems that the transmission efficiency is affected by high resistance loss of the cable and the structural stability is poor.

The application discloses a kind of HVDC valve voltage-sharing resistor selection design method, equipment and medium, with the following beneficial effects: the application establishes the static charging simulation model of converter valve, further based on the static charging simulation model of converter valve is carried out static charging voltage imbalance degree simulation, discharge time simulation, in addition, the application also calculates the loss of voltage-sharing resistor of different resistance value under the rated operating condition of converter valve, and the heat output and operating temperature simulation of voltage-sharing resistor under the extreme severe condition of converter valve;Through the above mode, the application considers the selection of voltage-sharing resistor parameter from the voltage-sharing effect of converter valve, operating loss, discharge time, the operating power and temperature of voltage-sharing resistor and so on, and preferably realizes voltage-sharing and reduces loss, and the stable and safe operation of voltage-sharing resistor.

The utility model belongs to the technical field of photovoltaic cell assemblies, and provides a heterojunction main-grid-free cell assembly, which comprises a protective frame, and a sealing mechanism is assembled at the top of the protective frame; the battery mechanism is mounted in the protective frame; the battery mechanism comprises a crystalline silicon substrate located in the protective frame, and intrinsic amorphous silicon layers are installed on the front face and the back face of the crystalline silicon substrate. A P-type amorphous silicon layer is assembled on the intrinsic amorphous silicon layer on the front face of the crystalline silicon substrate, and an N-type amorphous silicon layer is installed on the intrinsic amorphous silicon layer on the back face of the crystalline silicon substrate. The light receiving area of the cell mechanism is increased through a main-grid-free electrode mechanism, meanwhile, the thin grid lines are of a variable cross-section structure, the cross section of the part, close to the edge of a cell piece, of the thin grid lines is gradually increased, resistance loss in the current transmission process is reduced, the current collection efficiency is improved, and the photoelectric conversion efficiency is improved by combining the efficient photoelectric conversion performance of a heterojunction structure. And the power generation efficiency of the device is obviously improved.

The utility model relates to the technical field of high-voltage wire clamps, and discloses a high-voltage transmission line wire clamp device. The utility model aims to solve the technical problems that in the prior art, the mechanical strength and durability are insufficient, the electrical performance is poor, the resistance loss is large, the power transmission efficiency is further reduced, the cable is further difficult to adapt to outdoor complex environments, and the cable does not have corrosion resistance and lightning protection capability. The cable comprises a strain clamp, the strain clamp comprises a drainage plate and a strain pipe, the strain pipe comprises a wire crimping area, a first non-crimping area, a steel anchor crimping area and a second non-crimping area, a stranded wire is connected in the wire crimping area through a crimping technology, and a steel anchor crimping groove is arranged in the steel anchor crimping area to accommodate a steel anchor. The stranded wire and the steel anchor are connected through a crimping process in the first non-pressing area, and the welding part of the drainage plate and the strain pipe is located in the second non-pressing area. The utility model aims to improve the efficiency, safety and stability of power transmission, and is suitable for various application scenes in a modern high-voltage power transmission network.

The application discloses a loss evaluation method for a no-loop-flow air-core reactor, and belongs to the technical field of reactor design. The no-loop-flow air-core reactor comprises a reactor coil which is wound by N aluminum flat wires. The aluminum flat wires are independently wound on each star frame arm. Each aluminum flat wire is wound by only N / 1 circle to enter the next circle. The N aluminum flat wires are wound according to the number of the amplitude aluminum flat wires which are wound by each package in a single-layer structure, and then the N aluminum flat wires continue to wind the next layer structure along the reverse direction after the single-layer structure is completed, until the whole reactor coil is wound. Since the equal wire length principle is adopted when the reactor is wound, there is no loop-flow loss in the reactor. The total loss of the reactor is the sum of the resistance loss and the eddy current loss. When the loss calibration of the reactor is performed, the accurate theoretical calculation of the internal magnetic field loss of the new series no-loop-flow reactor is realized, and the influence of the actual loss detection of the reactor caused by the additional loss of the external environment during the actual test is corrected.

The invention belongs to the field of carbon fiber composite materials, and discloses a lightweight superconductive carbon fiber composite cable and a preparation method thereof, the cable is composed of a carbon fiber bundle layer, a multifunctional composite coating, a superconductive functional layer, an insulating layer, a shielding layer and a protective layer in sequence; the multifunctional composite coating is prepared from 60 to 65 parts of a polyamide acid precursor, 8 to 12 parts of 4-aminopropyltrimethoxysilane, 1 to 2 parts of glutaraldehyde, 3 to 5 parts of graphene nanosheets and 15 to 20 parts of a YBaCuOx precursor; a YBaCuOx ceramic layer with oriented crystals and continuous micro-channel cooling is obtained on the surface of the composite coating in situ by the superconductive functional layer through a pre-sintering, calcining and annealing cycle process combining sol-gel deposition and supercritical COdrying; the prepared cable has the advantages of high critical current density, zero resistance loss, excellent thermal-mechanical stability and extremely low self weight, and is suitable for the fields of high-frequency and long-distance lossless power transmission and low-temperature magnetic resonance.

The invention belongs to the technical field of crystalline silicon Topcon multi-fragmentation high-efficiency photovoltaic cell preparation, and particularly relates to a crystalline silicon Topcon multi-fragmentation high-efficiency photovoltaic cell and a preparation method thereof, and the cell is a 4, 5 or 6 equally-divided small cell obtained by carrying out laser cutting and edge passivation on a whole Topcon cell with a specific multi-fragmentation pattern layout. The production method mainly comprises the following steps: after multi-fragment pattern printing, cutting the whole cell into a plurality of small pieces by laser, and carrying out atomic layer deposition aluminum oxide passivation treatment on exposed edges generated by cutting. According to the invention, the series resistance loss of the module is reduced through the multi-fragment design, and the cutting damage is effectively repaired and the carrier recombination is inhibited by combining an innovative cell end edge passivation process, so that the output power of the module is remarkably improved on the premise that the size of the module is not changed.

According to the light superconductive carbon fiber composite cable and the preparation method thereof provided by the invention, the problem of resistance loss caused by grain boundary scattering in a graphene cable is solved by combining a graphene grain boundary repairing technology of a metal state on the surface of a topological insulator. The preparation method comprises the following steps: directionally depositing Bi2Se3 nanosheets on a graphene crystal boundary by using argon current carrying under the condition of 450-550 DEG C through a chemical vapor deposition process to form a continuous conductive channel. According to the method, complex lattice matching is not needed, the strict requirement of double-layer graphene on the magic angle precision is avoided, and the process error-tolerant rate is high. The surface metal state of the topological insulator improves the conductivity of the graphene by 20%-30%, and meanwhile, a dissipation-free topological edge state is reserved. The technology is combined with the light superconductive carbon fiber composite cable, so that the conductivity and mechanical stability of the cable are remarkably improved, and the light superconductive carbon fiber composite cable has a wide application prospect.

This utility model discloses a low-smoke halogen-free flat cable resistant to high temperature and humidity aging, relating to the field of cable technology. It includes a conductor layer, an insulation layer, a filler layer, an inner sheath layer, a shielding layer, a tensile reinforcement layer, an outer sheath layer, and a moisture-proof layer. Through a multi-layered structural design, this utility model forms a complete protective system, effectively improving the cable's resistance to high temperature and humidity aging. The conductor layer uses multi-strand copper wires tightly twisted together, improving the conductor's conductivity and mechanical strength, reducing the skin effect, and lowering resistance loss. The insulation layer is made of low-smoke halogen-free, high-temperature resistant insulating material, covering the outside of the conductor layer. It not only has excellent insulation performance but also maintains stable physical and chemical properties under high-temperature environments, preventing softening and deformation. Furthermore, it produces low smoke and halogen-free combustion, making it environmentally friendly and safe. The filler layer is located in a groove outside the insulation layer, filling the gaps around the flat conductor layer and improving the cable's overall stability and resistance to deformation.

The invention provides a circuit assembly. The circuit assembly comprises a first semiconductor element, a second semiconductor element and an energy storage element, wherein the first semiconductor element and the second semiconductor element are arranged to be electrically isolated from each other; wherein the first end of the first semiconductor element and the first end of the second semiconductor element are electrically connected to one end of the energy storage element respectively. Since the two semiconductor elements are arranged to be electrically isolated, their respective duty cycles are not or almost not affected, thereby improving overall performance. In addition, the arrangement of the semiconductor element and the energy storage element can help to achieve a more compact circuit design, thereby saving space and improving integration density. Further, such an arrangement of the semiconductor element and the energy storage element can shorten a wiring distance between the semiconductor element and the energy storage element, thereby reducing resistance loss and improving efficiency of the circuit.

The invention relates to a camouflage material and a camouflage net. The camouflage material comprises a base material layer and a functional layer. The functional layer is formed on at least one side surface of the base material layer through a vacuum sputtering process, and the sheet resistance of the functional layer is 100-450 omega / square. A uniform and compact film functional layer is formed on the surface of a base material through vacuum sputtering, and the sheet resistance value is designed in a specified range, so that the sheet resistance value of the functional layer is close to free space wave impedance, thereby realizing good impedance matching and promoting incident radar waves to enter the material to the greatest extent to realize multiple reflection attenuation instead of reflection. And in addition, radar wave energy can be effectively attenuated in combination with a resistance loss mechanism of the material. Compared with traditional processes such as carbon paste coating and the like, accurate and stable control over square resistance can be achieved through vacuum sputtering, the coating is high in adhesive force and uniform in thickness, the consistency and reliability of the wave absorbing performance can be improved, the problem that a traditional camouflage net fails to detect SAR radar is solved, and the camouflage effect of the radar wave band is remarkably improved.

A method includes obtaining measurement data indicative of a measured temperature profile at a position of an electrical part based on a first temperature of the electrical part over time relating to a self-heating due to resistive loss of the electrical part, and at least a second temperature over time relating to a heating due to resistive loss of a surrounding portion of the electrical system; obtaining characteristic data of the electrical part comprising at least one characteristic temperature profile of a temperature of the electrical part over time due to the self-heating of the electrical part or of a temperature of the electrical part over time due to the heating of the surrounding portion; and determining the first temperature of the electrical part over time based on the measurement data and the characteristic data.

The present invention discloses an energy-saving high-voltage switchgear and control method, which relates to the field of energy-saving technology for high-voltage switchgear, and includes a high-voltage switchgear body, a multi-modal busbar monitoring unit, and an active electromagnetic compensation unit. The multi-modal busbar monitoring unit is installed on the periphery of multiple busbars of the high-voltage switchgear body, and monitors the temperature and non-contact pressure fluctuations of the multiple busbars respectively. By monitoring the temperature and non-contact pressure fluctuations of the busbars in real time, it is possible to accurately predict the change in busbar resistance, thereby performing electromagnetic compensation in a timely manner when the resistance increases, reducing losses during power transmission. Active electromagnetic compensation can dynamically adjust the compensation magnetic field to ensure the stability of the busbar contact point resistance, reduce arcing and faults caused by poor contact, and improve the stability and reliability of the system. By reducing resistance losses, the overall energy consumption of the switchgear is reduced, which contributes to energy conservation and emission reduction, and is in line with the development trend of green environmental protection.

The invention discloses hollow ferroferric oxide nanoparticles as well as a preparation method and application thereof. The hollow ferroferric oxide nano-particle has an open hollow spherical structure, the particle size is 400-1000 nm, the diameter of an internal cavity is 200-500 nm, and the hollow ferroferric oxide nano-particle comprises micropores with the diameter of 10-60 nm. The preparation method of the hollow ferroferric oxide nano-particles comprises the following steps: 1) preparing magnetic nano-particles; and 2) removing the polystyrene microspheres in the magnetic nanoparticles through solvent dissolution or calcination. The hollow ferroferric oxide nano-particles can achieve the coupling effect of interface polarization and resistance loss to enhance dielectric loss, have excellent microwave absorption performance, are good in stability, light in weight, simple in preparation method and low in production cost, and a microwave absorption material prepared by dispersing the hollow ferroferric oxide nano-particles in polypyrrole has an excellent electromagnetic shielding effect and can be widely applied to the field of microwave absorption materials. The method is suitable for large-scale industrial production and application.