302results about How to "Improve power density" patented technology

The invention discloses a high-efficiency converter for adjusting the voltage of a power grid, and belongs to the technical field of power electronics. The converter comprises a first voltage regulation circuit, a second voltage regulation circuit, a filter circuit, a detection circuit and a control circuit. By detecting the amplitude difference between the power grid voltage and the load voltage, the control circuit automatically switches the Buck working mode or the Boost working mode, and stable alternating current output in a wide input voltage range is achieved. The invention has the advantages of compact structure, high efficiency, fast response, small harmonic wave and the like, and is suitable for industrial and civil occasions with large-range fluctuation and frequent power grid voltage.

The invention discloses a totem-pole PFC circuit control method and device based on an improved SOGI-PLL, and belongs to the technical field of totem-pole PFC circuits, and the method comprises the steps: collecting the input voltage, input current and bus voltage of a totem-pole PFC circuit; synchronous phase information of the power grid voltage is obtained through an improved second-order generalized integral phase-locked loop; generating a current amplitude reference signal, and combining the current amplitude reference signal with the synchronous phase information to synthesize a current reference signal; generating a pulse width modulation signal for controlling a high-frequency switching tube; and a switching signal of the power frequency switching tube is generated based on the synchronous phase information, and the power frequency switching tube and the high-frequency switching tube are driven in combination with the pulse width modulation signal, so that the action time sequence is synchronous with the phase of the power grid voltage, and therefore, waveform tracking of the input current is realized, and current distortion at the zero crossing point is suppressed. Precise phase synchronization is realized based on the improved SOGI-PLL, totem pole PFC zero-crossing current distortion is effectively suppressed, and the power factor and waveform quality are improved.

The invention relates to an epoxy resin pouring type transformer with built-in microcirculation cooling channels and a heat dissipation method of the epoxy resin pouring type transformer, and belongs to the technical field of power transformers. The epoxy resin pouring type transformer comprises an iron core, a low-voltage winding, a high-voltage winding and a heat dissipation shell, the low-voltage winding and the high-voltage winding are completely impregnated and wrapped by an epoxy resin composite material through a vacuum pouring process, an integrated epoxy resin pouring body is formed after curing, and a three-dimensional communicated bionic microcirculation cooling channel network is arranged in the epoxy resin pouring body; the heat dissipation shell is in close contact with the outer surface of the epoxy resin pouring body through the high-heat-conductivity insulating medium. According to the invention, the heat dissipation efficiency can be remarkably improved, and a cooling medium (air) is directly guided to a microscopic area around the winding conductor through a three-dimensional communicated and tree-shaped fractal bionic microcirculation cooling channel network, so that the effective heat exchange area and the heat exchange strength are greatly increased, and internal heat can be accurately and efficiently taken away.

The application provides an inverse-conducting insulated gate bipolar transistor and a preparation method thereof, and belongs to the technical field of power semiconductor devices, and comprises: a first groove is a gate groove, a second groove is an emitter groove, and a third groove is an ineffective gate groove; in the lateral direction parallel to the cell surface, the first groove, the second groove and the third groove are sequentially and spacedly arranged, and the first groove and the second groove are connected through a fourth groove, and the fourth groove is a gate groove; in the longitudinal direction, the second groove is located between two adjacent fourth grooves. The beneficial effects are as follows: the gate groove and the ineffective gate groove are connected through the lateral gate groove, the forward conduction voltage drop and the conduction loss of the device are reduced; the current channel is increased, the current distribution is more uniform, the heat loss is reduced, the reliability and the power density of the device are improved; the emitter groove is used for repeatedly arranging the polysilicon gate and the metal gate in the lateral and longitudinal directions, the regularly arranged diodes and Schottky diodes are formed, and the reverse diode current distribution is more uniform.

The invention discloses a cavitation effect enhancing device of an ultrasonic cleaning machine and a multi-material workpiece accurate descaling method.The cavitation effect enhancing device is installed on the ultrasonic cleaning machine and comprises an intelligent control mechanism, a water flow jetting mechanism, a monitoring mechanism, a circulating assembly and a sealing protection assembly; the intelligent control mechanism can receive and analyze monitoring signals transmitted by the monitoring mechanism in real time and output control instructions to adjust working parameters of the water flow jetting mechanism, the ultrasonic transducer and the circulation assembly. The water flow spraying mechanism is located in the cleaning tank and used for spraying water flow to impact the workpiece and disturb the cleaning liquid. The ultrasonic cleaning device has the beneficial effects that through injection and water flow disturbance of the water flow injection mechanism, removal of dissolved gas in cleaning liquid is promoted, the number of cavitation bubbles is increased, meanwhile, the intelligent control mechanism dynamically adjusts the power of the ultrasonic transducer, the power density is improved, the collapse energy of the cavitation bubbles is enhanced, and the cavitation effect strength is remarkably improved.

The invention discloses a parallel port type hexagonal frequency mixing solid-state transformer and a regulation and control method and device thereof, and the method comprises the steps: under the conditions that the direct-current active power and the alternating-current active power of the solid-state transformer are equal, and the instantaneous active power absorbed by each sub-bridge arm is 0, calculating the frequency of each sub-bridge arm in each sub-bridge arm; the stability relation between the fundamental frequency alternating current port current distribution coefficient and the intermediate frequency alternating current port current distribution coefficient is determined; and calculating a bridge arm circulation current through the stability relationship, thereby calculating to obtain a bridge arm circulation voltage reference value, calculating to obtain a sub-module capacitor voltage reference value of each sub-bridge arm, superposing each sub-module capacitor voltage correction component of each sub-bridge arm, obtaining a corresponding optimized sub-module capacitor voltage, and generating a corresponding modulation signal. By the adoption of the technical scheme, the multi-scene access requirement of the alternating current and direct current hybrid power distribution network is met, and inherent decoupling of three-frequency components including direct current, fundamental frequency and intermediate frequency can be achieved without an additional frequency selection network under the corresponding control method.

The present application relates to the technical field of power electronic control, and discloses a split-phase inverter with low no-load power consumption, a control method thereof and a storage medium, wherein a group of complementary switching tubes is arranged on the AC side and a group of high-frequency switching tubes is arranged on the DC side, so that the complementary switching tubes and the high-frequency switching tubes are controlled to emit waves in a first wave-emitting mode when the split-phase inverter is in a starting state, thereby reducing the reactive circulating current of the split-phase inverter and reducing the no-load power consumption of the split-phase inverter; meanwhile, when the real-time output current of the split-phase inverter is greater than or equal to a first current threshold, the complementary switching tubes and the high-frequency switching tubes are switched to emit waves in a second wave-emitting mode, thereby ensuring that the split-phase inverter can be normally loaded; compared with the related prior art, the split-phase inverter can not only solve the problem of high no-load power consumption, but also does not need large-current switching tubes or large radiators, has a smaller product size, a high power density and a lower cost.

The invention provides a resonant converter parameter optimization method and system of an electric vertical take-off and landing aircraft, and relates to the technical field of aviation power electronics. The method comprises the following steps: constructing an improved equivalent circuit model containing transformer secondary side leakage inductance; deriving a voltage gain function expression of the improved equivalent circuit model and an optimization calculation formula of the excitation inductance required for realizing the soft switching; parameter optimization is carried out based on the voltage gain function expression and the excitation inductance optimization calculation formula; and building an LLC resonant converter experimental prototype according to the optimized parameters, and carrying out system verification and performance evaluation. According to the invention, the problem of performance reduction caused by neglecting secondary side leakage inductance under a high-frequency working condition in a traditional design is solved, the efficiency, the voltage stabilization precision and the power density of the converter are remarkably improved, and the high requirement of eVTOL on an airborne power supply is met.

This invention provides a coreless stator for a high current density axial flux motor and an axial flux motor. The coreless stator of the high current density axial flux motor includes at least one stator winding layer, which includes several circumferentially spaced and independent conductive coil units. In each stator winding layer, several conductive coil units are processed on a conductive substrate using a subtractive process. Each conductive coil unit includes a planar working portion extending straight in a radial plane, an outer transition line portion connected to the outer end of the planar working portion, and an inner transition line portion connected to the inner end of the planar working portion. At least one of the outer transition line portion and the inner transition line portion is bent wholly or partially relative to the planar working portion, thereby forming a three-dimensional transition line portion. This directly releases the radial plane space occupied by the outer transition line portion and the inner transition line portion, thereby significantly increasing the radial width and total area of ​​the effective electromagnetic working area and achieving a significant improvement in torque and power density.

The application discloses a high-rate valve-regulated lead-acid battery and a preparation method thereof. The battery comprises a battery shell, a positive plate, a negative plate and an electrolyte arranged in the battery shell. The positive plate and the negative plate are both honeycomb lattice structure plates, and the positive plate is coated with a positive active material, and the negative plate is coated with a negative active material. The components of the positive active material include lead powder, graphite, sulfuric acid, nano lead dioxide and pure water. The components of the negative active material include lead powder, barium sulfate, sodium lignosulfonate, graphene composite additive and carbon black. The discharge rate of the high-rate valve-regulated lead-acid battery can reach 3-5C, and the discharge capacity retention rate is above 95% under the 1C discharge rate, which can meet the demand of 5G base stations, data centers and other fields for instantaneous large current and high power output.

This application belongs to the field of wireless charging technology, specifically relating to a constant current and constant voltage wireless charging system and method based on a three-coil loosely coupled transformer, including an inverter circuit, a primary-side compensation circuit, a resonant circuit, a secondary-side compensation circuit, a rectifier circuit, and a filter capacitor; the resonant circuit has an anti-parallel coil structure, with the third coil located on the secondary side and a single coil on the primary side; its advantages are high misalignment tolerance, load-independent output, and high efficiency.

The utility model discloses a glue nozzle temperature on-line detection device, and relates to the technical field of adhesive sticker production, the glue nozzle temperature on-line detection device comprises a support frame member and a second closed structure member, the bottom of the support frame member is connected with a first joint member, and the second closed structure member is connected to one end of the support frame member far away from the first joint member. According to the glue nozzle temperature on-line detection device, the first joint component and the second joint component are arranged at the two ends of the supporting frame component respectively, a first electric joint and a second electric joint are each of a frameless torque motor structure, and by means of the arrangement of the structures, the whole device structure has the double-section structure movable adjustability; and meanwhile, a damping sleeve is used between the second closing component and the detection component, so that the detection component can realize axial rotation adjustment along the surface of the connecting pile, the structural flexibility is improved, and the device is convenient to use.

The utility model discloses a miniaturized high moment has brush motor, this motor aims at solving the inductance element and carbon brush assembly and terminal of existing motor inside adopt direct welding mode, cannot keep reliable contact in the problem of vibration environment. The motor includes the shell, the stator subassembly of fixed mounting in the shell inside, the rotor subassembly of rotation installation in the shell inside and with the terminal subassembly of rotor subassembly electricity is connected, and the terminal subassembly includes the middle plate, installs the inductance in the middle plate, carbon brush assembly and conducting terminal, and one end of inductance is fixed after welding with the conducting terminal riveting, and the other end of inductance is fixed after welding with carbon brush assembly riveting. The utility model passes through independent riveting welding inductance both ends, realizes inductance and brush arm, inductance and the high strength mechanical locking and conducting connection of conducting terminal, and the anti -vibration performance is superior to direct welding mode, can keep reliable contact in the vibration environment.

This invention discloses a low-temperature resistant, high-power aqueous organic-bromine battery, belonging to the field of electrochemical energy storage technology. The invention uses a low-freezing-point bromine-based salt solution with added bromine solid complexing agent as the electrolyte, and a pseudocapacitive organic material as the negative electrode, which possesses ionic universality and can bind metal ions in the solution during the reaction. The positive electrode uses a carbon material as a substrate, where a bromine redox reaction occurs. Simultaneously, the complexing agent can complex bromine in solid form onto the carbon surface, ensuring good stability at both room temperature and low temperatures. The aqueous organic-bromine battery of this invention exhibits high energy density and ultra-high power density at room temperature, maintains high energy density even at low temperatures, and is inexpensive, showing promising application prospects.

This application provides a highly integrated hydraulic power unit and its working method, relating to the field of hydraulic system technology. The unit includes a housing, a hydraulic pump, and a motor. The housing has an oil storage chamber, and the hydraulic pump is connected to the oil storage chamber and pumps hydraulic oil under the drive of the motor. The built-in oil storage chamber allows the oil supply process to occur entirely within the housing, eliminating the need for an external oil supply system, effectively reducing the overall size of the pump, and avoiding exposed oil supply lines. This application features multiple return oil channels around the motor, utilizing the hydraulic oil circulation process to cool the motor, enabling the installation of a high-power motor to increase power density. Furthermore, by implementing pressure-holding and shock-prevention measures, this application ensures that the pressure inside the oil tank remains positive, preventing instantaneous high-pressure shocks to the hydraulic pump. This allows the motor pump to continue pumping oil normally under harsh conditions, adapting to the shaking and swaying of mobile equipment during operation, and meeting the requirements for stable operation under adverse conditions.

The embodiment of the present application provides a motor, a power assembly and a vehicle. The motor comprises: a shell assembly, a cooling cavity for cooling oil flow being arranged in the shell assembly, the shell assembly being provided with an oil inlet and an oil outlet communicating with the cooling cavity; a stator assembly, at least part of the stator assembly being arranged in the cooling cavity, so that the stator assembly can be at least partially immersed in the cooling oil; and a rotor assembly, rotatably sleeved on the inner side of the stator assembly. In the scheme, at least part of the stator assembly can be immersed in the cooling oil in the cooling cavity and directly contact with the cooling oil, so that the contact type oil cooling is realized. In this way, the cooling oil can be in full contact with the stator assembly under the hydraulic action as much as possible, so that the stator assembly and the cooling oil can have a relatively large contact area, the heat dissipation area of the stator assembly is improved, and the flowing cooling oil can timely take away the heat of the stator assembly, so that the heat dissipation efficiency of the motor can be greatly improved compared with the oil shower type cooling scheme.

The application provides a flaky flower-like single-crystal sodium vanadium oxyfluorophosphate / carbon composite material, a preparation method thereof and a sodium ion battery. The flaky flower-like single-crystal sodium vanadium oxyfluorophosphate material is prepared through a hydrothermal reaction. A surfactant is used to control the crystal face growth direction in the material synthesis process, so that the sodium vanadium oxyfluorophosphate grows to form a flaky flower-like single-crystal structure, and then the ion transmission distance is shortened, the ion kinetic characteristics of the material can be effectively improved, and on the basis of ensuring the structural stability of the material, that is, the cycle performance, the rate characteristics of the material are effectively improved. Through carbon coating, the electronic conductivity of the surface of the material particles is improved, and the capacity rate performance of the material is effectively improved.

The application discloses a kind of high-efficiency super-soft organic solar cell of top incidence structure, it includes flexible substrate, anode, anode modification layer, active layer, cathode modification layer, cathode and antireflection layer from bottom to top, wherein the cathode is based on the transparent electrode of ultrathin silver.Especially by preferred cathode modification layer and introducing not more than 2nm thick gold as seed layer, make ultrathin silver surface more smooth and uniform, the transparent electrode can further improve the photoelectric energy conversion efficiency (PCE) of organic solar cell.Meanwhile, using the wide adaptability of top incidence structure to different substrates, the organic solar cell can also achieve comparable PCE (17.32%) with mm level rigid glass substrate on the polyimide flexible substrate with thickness of only 1.3 μm.Therefore, the highest efficiency of super-soft organic solar cell so far is obtained, and the highest power density (39.72W g ‑1 ) in all photovoltaic technologies at present is also obtained.

The application discloses an unmanned aerial vehicle wireless charging coupling system, a coil winding method and an unmanned aerial vehicle, and belongs to the technical field of unmanned aerial vehicle charging. The charging coupling system comprises a transmitting device and a receiving device, the transmitting device comprises a transmitting coil, the receiving device comprises a receiving coil, and further comprises a landing device, the receiving device is arranged on the landing device, and the transmitting device is arranged in a parking area; the transmitting device comprises a ferrite, the ferrite comprises a connecting portion and a stepped symmetrical protruding structure extending outward at the end of the connecting portion, the ferrite as a whole is in a U shape, and the transmitting coil is wound vertically in the U-shaped structure of the ferrite; the receiving device comprises a soft magnet, the receiving coil is wound on both sides of the landing device, a rectangular gap is arranged in the middle of the receiving coil, the soft magnet is arranged in the rectangular gap, and the lower part of the soft magnet is attached to the lower part of the rectangular gap. The coupling system has small space occupation, large coupling coefficient, can realize efficient energy transmission, and is convenient to install and does not affect the flight performance of the unmanned aerial vehicle.

This application provides a voltage conversion circuit, a conversion device, and a conversion method, which can be applied in the field of voltage conversion technology. The voltage conversion circuit includes: a first terminal of a switching circuit of a step-down module electrically connected to a power supply, and a second terminal of the switching circuit electrically connected to multiple capacitors; the switching circuit is configured to control the multiple capacitors to switch between a series connection and a parallel connection under the control of a first control signal from a controller; in the series connection state, the multiple capacitors are charged by the power supply; in the parallel connection state, at least one of the multiple capacitors is discharged to output a discharge voltage; a conversion module converts the discharge voltage into an alternating voltage and outputs the alternating voltage; a transformer module transforms the alternating voltage to obtain and outputs a processed voltage; and a rectifier module rectifies the processed voltage to obtain a target voltage.

The application discloses a matrix transformer integrated with adjustable leakage inductance and a resonant converter, and relates to the technical field of power electronics. The matrix transformer comprises upper, middle and lower cover plates, a plurality of magnetic columns, a primary winding and a secondary winding. The magnetic columns are arranged between the upper and lower cover plates, and each of the magnetic columns is provided with an air gap. The middle cover plate is arranged between the upper and lower cover plates and penetrates through each air gap. The primary winding is wound on the magnetic column close to the upper cover plate, and the secondary winding is wound on the magnetic column close to the lower cover plate. After being electrified, the magnetic field generated by the primary current excitation passes through the upper cover plate-magnetic column-lower cover plate-magnetic column-upper cover plate to form a main magnetic flux loop, and passes through the upper cover plate-magnetic column-middle cover plate-magnetic column-upper cover plate to form a leakage magnetic flux loop. The size of the leakage inductance of the leakage magnetic flux loop is adjusted by adjusting the structural parameters and design conditions of the middle cover plate. The application realizes accurate control of the size of the leakage inductance of the transformer and integration of the resonant inductance and the transformer.

The application discloses a bidirectional DC-DC converter and a control method, the converter adopts a magnetic integration technology and a switching multiplexing technology to combine a Boost circuit and a series resonant circuit, and realizes single-stage bidirectional DC-DC power conversion; compared with a two-stage converter composed of a traditional Boost and series connection, the number of power switching devices is reduced, and the efficiency and power density of the converter are improved; through the Boost interleaved parallel technology on the low-voltage side, the input current ripple is almost zero, the application occasions of the converter are increased, and the converter is particularly suitable for various applications such as a battery energy storage system and a new energy vehicle.

The application discloses an isolated switching converter, a controller and a control method thereof. The switching converter comprises a transformer with a primary winding and a secondary winding, a primary switch tube coupled to the primary winding, and a secondary switch tube coupled to the secondary winding. The control method comprises: sampling and holding the maximum value of the voltage across the secondary switch tube to provide a first voltage signal; providing a second voltage signal smaller than the first voltage signal based on the first voltage signal; starting timing when the voltage across the secondary switch tube reaches the second voltage signal and ending timing when the voltage across the secondary switch tube increases to the first voltage signal, and the timing time is a first time length; and adjusting the turn-on time length of the secondary switch tube in the second turn-on to make the first time length of the next switching cycle close to a first time threshold. According to the embodiment of the application, the primary switch tube can be completely turned on at zero voltage under a wide input and output range.

The invention relates to the technical field of conductive thin film materials, in particular to a preparation method and application of a pure-carbon-series self-supporting conductive thin film. Comprising the following steps: S1, uniformly stirring and mixing multi-walled carbon nanotube slurry, single-walled carbon nanotube slurry and graphene slurry, adding a film-forming agent oily solution, and uniformly mixing to obtain a coating material; s2, coating a substrate with the coating material in the S1, and then drying and stripping to obtain the pure-carbon-series self-supporting conductive thin film, the sheet resistance of the pure carbon system can reach 4.2 omega / square, and the sheet resistance of a thin film prepared in a general laboratory is less than 20 omega / square and is superior to that of an existing pure carbon film (generally gt and 20 omega / square), and the pure carbon film can be driven under the low voltage of 5V. Due to the characteristic, the deicing device is particularly suitable for the fields of flexible wearable equipment, consumer electronics, deicing in special environments and the like.

The application discloses an enhanced water-vapor power generation device and a preparation method thereof, and belongs to the technical field of water evaporation power generation. The enhanced water-vapor power generation device comprises a substrate and reduced graphene oxide fibers loaded on the substrate, and the two ends of the substrate are connected with conductive parts; wherein the reduced graphene oxide fibers are compounded with a high-molecular conductive polymer, and the high-molecular conductive polymer is made of a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) solution with enhanced conductive performance. The enhanced water-vapor power generation device can effectively improve the structural stability of the reduced graphene oxide material under long-term hydration, avoid or reduce the occurrence of structural expansion or peeling, and enhance the stability of the material structure. The poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) and the reduced graphene oxide form a three-dimensional continuous conductive path, reduce the interface contact impedance, accelerate the electron migration rate of the water-vapor power generation device, and thus improve the power generation performance of the device.

The utility model belongs to the technical field of motor rotors, and particularly relates to a spoke type motor stator and rotor structure, which comprises a rotor core and a stator core, a plurality of material-saving holes are arranged in the rotor core, a shaft hole is arranged in the middle of the rotor core, a plurality of mounting grooves are circumferentially arranged in the rotor core, and magnets are arranged in the mounting grooves. According to the utility model, the height of the magnet is increased, and the flux density of the iron cores at the two ends of the rotor is increased, so that the air gap flux density is increased, and the efficiency and the power density of the motor are improved.

The utility model relates to a crane controller with an integrated structure. The crane controller comprises a wireless communication unit, a logic control unit, a motor control unit A, a motor control unit B, a motor control unit C, a signal interface unit and a radiator. Compared with the prior art, the utility model has the advantages that: 1) the wireless communication unit, the logic control unit, the motor control unit A, the motor control unit B and the motor control unit C adopt an integrated design, the structure is compact, and the cost is low; 2) the signal interface adopts a quick plugging mode, so that the installation and the maintenance are convenient; and 3) the wireless communication unit and the logic control unit are integrated on one circuit board, the control is flexible, and the reliability is high. And 4) the motor control unit A, the motor control unit B and the motor control unit C all adopt modular design and are integrally fixed on the radiator, so that the power density is high, the size is small, and light weight is facilitated. And 5) an integrated structure design is adopted, a rapid plugging connection mode is adopted, the protection level is high, and the product life cycle is long.

The utility model provides a kind of UL off-grid inverter, belong to inverter technical field, it includes, DC / DC step-up and step-down circuit, for completing battery step-up and step-down, voltage equalizing circuit, for ensuring that two-phase voltage amplitude of inverter is symmetrical, output zero line is taken to DC bus midpoint, two-phase three-level inverter circuit, for output specified AC voltage, by DC / DC step-up and step-down circuit and voltage equalizing circuit cooperation, make DC input first through high-frequency isolation step-up and step-down, positive and negative bus keep symmetry, common-mode noise is greatly reduced, electromagnetic compatibility is better, two-phase inverter bridge and LC filter combination after output voltage harmonic is extremely low, power quality meets UL off-grid requirement, L1 and L2 end with same neutral point N as reference, can software setting zero degree cophasal parallel output 120V large current, or 180 ° split-phase output 240V, hardware does not need additional transformer or switch, volume weight reduces, cost drops accordingly.

This invention relates to the field of new materials and electrochemical energy storage materials, and discloses a polyimide-derived hierarchical porous carbon / carbon fiber composite electrode and its preparation method. The preparation method involves using carbon fiber felt as a substrate, and constructing a three-level interconnected structure of micropores, mesopores, and macropores through polyimide solution spraying, metal-organic gel template deposition, gradient carbonization, and eutectic activation processes. This invention, through template synergy and optimized activation processes, enables the constructed composite electrode to possess a unique three-level interconnected structure of micropores, mesopores, and macropores, solving the problems of limited mass transfer and insufficient active sites in traditional carbon electrodes. It can be widely applied to all-vanadium, iron-chromium, and organic flow batteries, and has significant industrial application value.