1627results about How to "Improve power density" patented technology

The invention discloses a three-phase permanent magnet synchronous motor full-speed-domain driving control system and a control method thereof. The system is composed of a torque limiting module, a full-speed-domain control neural network module, a current control module, a coordinate transformation module-I, a coordinate transformation module-II, a coordinate inverse transformation module, an SVPWM module, a SiC MOSFET driving module, a full-speed-domain position rotating speed observation module, a weak magnetic feedback module and a three-phase permanent magnet synchronous motor. The control method is used for driving the control system. According to the method, accurate tracing of the optimal dq-axis reference current working point is realized based on deep learning, and accurate control of three operation modes of MTPA, field weakening control and MTPV is realized; an improved mobile vision field estimation algorithm is adopted, and the rotor position and the rotor rotating speed are accurately estimated within the full-speed domain range; the SiC MOSFET is used as an inverter switching tube, and a brand new drive circuit is designed to adapt to the operation condition of the electric vehicle.

The invention discloses a high-integration-level and efficient-cooling external rotor motor ducted fan system, which belongs to the technical field of ducted fans and comprises a motor stator winding and a fan external rotor integrated part integrally formed by fan blades and a motor external rotor turntable, the integrated shell is integrally formed by a motor inner stator sleeve, a ducted nacelle, a motor controller main shell and a plurality of groups of ducted stationary blades; a cooling structure is mounted on the integrated shell; a motor stator winding is fixedly connected to the outer wall of one end of the integrated shell, the front flow guide cover is fixedly connected to the fan outer rotor integrated part, and the rear flow guide cover is installed at the other end of the integrated shell. And the integrated shell is rotationally connected with the fan outer rotor integrated piece. The system is low in noise, high in integration level, high in system reliability, high in system cooling efficiency, high in power level compatibility and high in expandability.

The invention discloses an equal-sectional-area high-slot-fullness-rate concentrated flat wire winding layout structure. The flat wire winding layout structure comprises a plurality of flat wire windings and a stator core with non-rectangular stator slots, each flat wire winding is wound on a respective stator core tooth part in the stator core and arranged in the same manner, and the width of each layer of flat wires of each flat wire winding is increased layer by layer from the narrower side to the wider side of the stator slot of the stator core. The thickness of each layer of flat wire is increased layer by layer from the wider side to the narrower side of a stator slot of the stator core, the total sectional area of each layer of flat wire is the same, and the wire ends of the flat wire windings are mutually connected at the end part of the motor. According to the invention, the slot fill factor of the flat wire winding in the non-rectangular slot can be effectively improved, the problem of low space utilization rate is solved, the efficiency and power density of the motor are further improved, the current densities at different positions of the conductor in the slot are basically the same, the insulation failure caused by too high local temperature rise is avoided, and the reliability of the winding can be effectively improved.

The invention discloses a high-heat-dissipation integrated ducted fan electric propulsion system, which belongs to the technical field of ducted fans and comprises a motor controller, a motor, a motor front bearing, a motor rear bearing, a front fairing, a rear fairing and an integrated fan rotating shaft integrally formed by fan blades and a motor rotating shaft. The integrated nacelle motor shell is integrally formed by a motor shell, a ducted nacelle and a plurality of groups of ducted stationary blades; cooling devices are mounted on the motor shell and the motor controller; the cooling device comprises a cooling water channel and a water cooling cavity; a cooling water channel is arranged on the motor shell; the motor controller is provided with a water cooling cavity, and the cooling water channel is communicated with the water cooling cavity; the front fairing is connected to the left end of the integrated fan rotating shaft, and the rear fairing is connected to the right end of the motor controller. The integrated level is high, the size and the weight are reduced by reducing connecting parts, and the power density is high; the system reliability is high; the system cooling efficiency is high; and the power level compatibility and the expandability are high.

The invention discloses a high-power all-gallium nitride LED driving power supply circuit which comprises an EMI filtering and rectifying circuit, a GaN active power factor correction circuit, a GaN half-bridge LLC resonant converter circuit and a GaN synchronous rectifying and filtering circuit. The PFC and LLC combined control module integrates a power factor correction function and a resonance circuit frequency regulation function, the GaN active power factor correction circuit is connected with the PFC and LLC combined control module to realize power factor correction, and the GaN half-bridge LLC resonant converter circuit is connected with the PFC and LLC combined control module to realize output power regulation; and a constant-current voltage-limiting feedback circuit for outputting current and voltage detection feedback is arranged between the GaN synchronous rectification filter circuit and the PFC and LLC combined control module. The advantages of high efficiency of the GaN switching tube and high working frequency of the circuit are utilized, so that power loss and heat dissipation requirements are reduced, and the efficiency and power density of the LED power supply are improved. The invention has the advantages of high efficiency, high power density, high reliability and the like.

The invention discloses a method for preparing a composite iron-based polyanion positive electrode material. The structural formula of the positive electrode material is represented as Na4Fe3 (PO4) 2 (P2O7) (at) Camp, mXenes are sodium ferric pyrophosphate compositely coated by an MXenes material and a carbonaceous precursor, and the preparation method comprises the following steps: weighing a sodium source, a ferrous source, a phosphorus source and a carbon source according to a stoichiometric ratio, uniformly mixing, grinding, spray-drying and sintering at high temperature to obtain the composite iron-based polyanion positive electrode material, and the carbon source comprises iron-nickel doped polyethylene glycol. The composite iron-based polyanion positive electrode material provided by the invention is remarkably improved in the aspects of energy density, rate capability and cycle life, and the preparation process is simple to operate, reliable in flow, quick in preparation process and easy for industrial production, so that an ideal scheme is provided for commercialized sodium ion battery positive electrode materials.

The invention relates to a permanent magnet synchronous motor design method based on a multi-objective optimization algorithm, and the method achieves the efficient design and optimization of a permanent magnet synchronous motor through the combination of finite element simulation, multi-physical field coupling analysis, neural network performance prediction, and a hybrid optimization algorithm of a genetic algorithm and particle swarm optimization. The method comprises the following steps: determining a plurality of design targets according to an application scene of a motor, selecting key design variables, performing data cleaning and normalization processing, performing electromagnetic field, thermal field and mechanical field simulation by using a multi-physics field coupled finite element model, predicting the performance of the motor by combining LSTM and Transform neural network models, expanding a training data set through a data enhancement technology, and performing data enhancement on the motor. Finally, a hybrid optimization algorithm combining a genetic algorithm and particle swarm optimization is adopted to carry out global optimization and adaptive adjustment of design parameters, and a Pareto optimal leading edge is utilized to find out an equilibrium solution between design targets, so that the accuracy and efficiency of motor design are improved, and the method is suitable for various motor design scenes.

The invention provides a lignite-based supercapacitor activated carbon electrode material and a preparation method thereof, and belongs to the technical field of electrochemical power supply material preparation. The preparation method comprises the following steps: S1, performing hydrochloric acid pickling on lignite raw coal powder for X2 hours, performing hydrofluoric acid pickling for X2 hours, and heating a calcium phosphate solution for deoxidation to obtain pretreated lignite; s2, uniformly stirring and mixing the pretreated lignite, an alkaline activator and deionized water according to the mass ratio of 1: X4: (5-10) to obtain a mixture; s3, activation is conducted, the activation temperature is X1 DEG C, and the activation time is X3 h; cooling to obtain a roasted product; s4, acid pickling with diluted hydrochloric acid; the specific capacitance of the active carbon electrode material is Y F / g, wherein Y = a + b * X1 + c * X2 + d * X3 + e * X4-f * X1 * X2 + g * X1 * X3 + h * X1 * X4 + i * X2 * X3 + j * X2 * X4 + k * X3 * X4-l * X12-m * X22-n * X32-o * X42. The preparation method is simple, the cost is low, the process repeatability is good, the prepared porous carbon has a high specific surface area, and the power density and the cycling stability of the supercapacitor are improved.

The invention discloses a DAB-based two-stage DC-AC converter system, which is composed of a dual-active full-bridge DC-DC converter and a single-phase grid-connected inverter, and is characterized in that the dual-active full-bridge DC-DC converter is formed by connecting a primary side full bridge and a secondary side full bridge through a high-frequency transformer HFL and a resonance circuit composed of Cr and Lr; the single-phase grid-connected inverter comprises an inverter full bridge composed of switch tubes K1-K4 and an LCL type grid-connected filter circuit composed of inductors L1 and L2 and a capacitor C; the invention further discloses a secondary ripple suppression method and a control strategy, the pulse power of double frequency multiplication in the direct-current bus capacitor is transferred to the LC power decoupling branch through the LC passive branch connected to the middle point of the secondary side of the double active bridge, so that power decoupling is achieved, and the secondary ripple suppression in the direct-current bus voltage keeps the bus voltage stable.

According to the supercritical CO2 circulation and water electrolysis hydrogen production coupled alcohol-electricity co-production system and method, water in an electrolytic bath is electrolyzed through wind and light abandoned electricity, and oxygen and hydrogen are generated. Oxygen and coal are subjected to pure oxygen gasification in a gasification furnace, and generated gasified gases (mainly including methane CH4, hydrogen H2 and carbon monoxide CO) are subjected to direct-fired supercritical CO2 circulation for power generation. Waste gas exhausted by the turbine is subjected to heat recovery through the heat regenerator, water is condensed in the condenser, and remaining CO2 is fed into the gas tank to be stored. One part of CO2 is pressurized by a compressor and then is fed into the combustion chamber through a heat regenerator, and the other part of CO2 and H2 are catalyzed to synthesize methane. According to the system, wind and light abandoned electricity can be converted into hydrogen energy to be stored, efficient clean power generation of coal and synthesis of green methanol are achieved through direct-fired supercritical CO2 circulation, and the green methanol / electricity co-production system with zero carbon emission is formed.

The invention relates to a multi-phase magnetic coupling structure, a series compensation circuit and a wireless charging system, and relates to the technical field of wireless power transmission, the multi-phase magnetic coupling structure comprises a primary side magnetic energy emission structure and a secondary side magnetic energy receiving structure, the primary side magnetic energy emission structure comprises a first magnetic core and an emission coil; the secondary side magnetic energy receiving structure comprises a second magnetic core and a receiving coil; the transmitting coil and the receiving coil are both multi-phase bipolar coils; therefore, the magnetic coupling structure provided by the invention is higher in magnetic field intensity, higher in power density and obviously improved in transmission efficiency, the transmission efficiency of the structure can reach more than 94% after the front end voltage is increased to 50V, and the highest efficiency is close to 96%.

The invention discloses a lithium battery diaphragm and a preparation method and application thereof, the lithium battery diaphragm comprises a base membrane and a coating on the base membrane, and the coating comprises gamma-phase superfine porous alumina. The method for preparing the lithium battery diaphragm comprises the steps that a base membrane is coated with slurry, drying is conducted, a coating is obtained on the base membrane, the lithium battery diaphragm is obtained, and the slurry comprises water, gamma-phase superfine porous aluminum oxide, an adhesive and a dispersing agent. The gamma-phase superfine porous aluminum oxide has a rich powder pore structure, so that the weight of the diaphragm is reduced, and the lithium battery diaphragm disclosed by the invention has high ion conductivity and high wettability while having high temperature resistance. The high-safety lithium ion battery diaphragm is an important way for improving the safety and the cycling stability of a lithium battery.

The invention belongs to the technical field of wind power generation, and particularly relates to a wind storage combined system for coordinated control of hybrid energy storage equipment and a control method. Wherein the wind generating set is used for converting wind energy into electric energy and outputting the electric energy to a power grid; the energy storage equipment comprises a battery energy storage system and a super capacitor; the direct current bus is used for being connected with the wind generating set, the battery energy storage system and the super capacitor through a control system and performing energy exchange with a power supply grid; and the control system is used for carrying out coordinated control on the energy storage equipment based on different power regulation requirements. According to the invention, the problems of power grid frequency fluctuation and power imbalance caused by wind speed fluctuation of the wind power generation system can be solved. Two different types of energy storage devices are integrated, cooperative regulation and control are carried out by utilizing respective characteristics of the energy storage devices, and power dispatching and frequency modulation control of different time scales are realized, so that the stability of a wind power generation system and the reliability of a power grid are improved.

The invention belongs to the field of flow heat transfer testing devices and the technical field of semiconductor chip and integrated circuit packaging heat dissipation, particularly relates to a flow heat transfer testing device and method for a 3DIC, and aims to solve the problem of heat management experiment testing of a 3DIC structure under the condition of high heat flux. The device comprises alternately stacked open type heating sheet slots, micro-channel modules, MCH ceramic heating sheets, interlayer communication columns, a flow distributor and a plurality of temperature measuring elements. Through a reasonably designed fluid distribution system and a precise heat conduction structure, an equivalent substitution experiment scheme of a real 3DIC is realized, the problem of small-space temperature measurement point and heat source arrangement is solved, and the problems of non-uniform flow distribution of gas-liquid two-phase flow in a variable cross-section sub-runner and the like are solved. The device has a real-time temperature monitoring capability, is suitable for thermal management research and multiphase flow pattern observation of 3DIC, and provides a scientific basis for optimization design and performance improvement.

The invention discloses a preparation method of a self-humidifying membrane electrode of a proton exchange membrane fuel cell, relates to a preparation method of a membrane electrode, and aims to solve the technical problem of poor performance of the conventional self-humidifying membrane electrode. The method comprises the following steps: 1, synthesizing a COFs material by using 2, 4, 6-triformyl phloroglucinol and 2, 5-diaminobenzene sulfonic acid through a two-phase method; 2, preparing slurry a by using a Pt / C catalyst and a perfluorosulfonic acid ionomer solution; preparing self-humidifying catalyst layer slurry b from a COFs material, a Pt / C catalyst and a perfluorosulfonic acid ionomer solution; and 3, coating the slurry a on the anode surface of the proton exchange membrane, and coating the slurry b on the cathode surface to obtain the self-humidifying membrane electrode. According to the electrode, H2 / O2 is used as fuel, and the power density is 756.3 mW / cm < 2 > under the relative humidity of 20%; h2 / air is used as fuel, the power density is 437.8-879.7 mW / cm < 2 > under the relative humidity of 50%, and the material can be applied to the field of fuel cells.

The invention relates to the technical field of energy storage converter fault detection, in particular to a fault detection circuit and method for an AC grid-connected relay of an energy storage converter. A primary relay is removed, a group of detection relay loop is added on the side of an alternating current grid-connected relay and a converter, and the detection relay loop is composed of a detection relay and a detection loop resistor. In the fault detection link of the alternating-current grid-connected relay, the voltage of the detection relay loop is judged by sequentially closing the detection relays of the detection relay loop, so that the short-circuit detection of the alternating-current grid-connected relay is realized. And then the detection relay loop is disconnected, the AC grid-connected relays are sequentially closed, and the voltage of the detection relay loop is judged, so that open circuit detection of the AC grid-connected relays is realized. The added detection relay loop is simple in structure and small in occupied space, the design cost of the alternating current grid-connected relay can be effectively reduced, and the overall structure utilization rate and the power density of the energy storage converter are improved.

The invention belongs to the technical field of carbon black post-treatment, and particularly relates to a method for preparing high-structure-degree carbon black through plasma sintering. In order to solve the problem that the structural degree of furnace-process carbon black is limited by a reaction furnace in the prior art, the invention provides the method for preparing the high-structural-degree carbon black by utilizing plasma sintering, and the structural degree of the carbon black is improved by utilizing a two-step method. Part of the aromatic hydrocarbon compound is left at the contact part of the carbon black to provide a carbon source for the next step of micro-sintering; in the second step, high-temperature plasma is adopted for heating, the carbon source can be rapidly carbonized in a short time, the micro-sintering phenomenon is generated among the carbon black, the size of a carbon black aggregation structure is increased, and therefore the structural degree is improved, and compared with traditional high-temperature heat treatment, the method can reduce energy consumption and consumed time in the treatment process to a greater extent.

The invention discloses a preparation method of a graphene oxide sodium alginate composite membrane for extracting ocean osmotic energy. The preparation method specifically comprises the following steps: step 1, preparing a sodium alginate solution; step 2, preparing a graphene oxide solution; 3, putting the sodium alginate solution into the graphene oxide solution, and carrying out electromagnetic stirring to obtain a mixed dispersion liquid; step 4, taking a polycarbonate film, taking the polycarbonate film as a substrate, putting the polycarbonate film into a trace suction flask, taking the mixed dispersion liquid, and performing vacuum suction filtration on the mixed dispersion liquid in the trace suction flask to obtain a polycarbonate film covered with a graphene oxide sodium alginate composite film; step 5, stripping the polycarbonate film covered with the graphene oxide and sodium alginate composite film, and naturally drying to obtain the graphene oxide and sodium alginate composite film for extracting the ocean osmotic energy. The invention further discloses the graphene oxide and sodium alginate composite membrane for extracting the ocean osmotic energy. The prepared composite membrane has the advantages of being high in power density, good in stability and high in economic value.

The invention relates to the technical field of permanent magnet generators, and discloses a high-speed high-power-density transverse flux permanent magnet generator which comprises a machine shell assembly, a power generation unit body is arranged in the machine shell assembly, the power generation unit body comprises a stator assembly and a rotor assembly, and the rotor assembly rotates in the stator assembly to achieve power generation; the stator assembly comprises a winding cooling mechanism and a concentrated winding, the winding cooling mechanism comprises a front semi-ring cooling sleeve, a rear semi-ring cooling sleeve, an upper diversion bridge and a lower diversion bridge, the front semi-ring cooling sleeve and the rear semi-ring cooling sleeve are buckled to form a winding cooling ring, and an inner ring flow channel, a mounting ring cavity and an outer ring flow channel which are concentric are formed in the winding cooling ring; the upper diversion bridge and the lower diversion bridge are used for communicating the inner ring flow channel with the outer ring flow channel to form a cooling passage, and the concentrated winding is adaptively arranged in the mounting ring cavity, so that the winding can be directly cooled in the generator, and the contradiction between multi-polarization and high-speed and high-frequency is effectively relieved; the torque density and the rotating speed range of the transverse flux permanent magnet generator can be simultaneously improved.

The invention belongs to the field of electric propulsion system motor driving, and particularly relates to a motor and controller integrated device for eVTOL. Comprising an integrated heat dissipation fan assembly, a motor assembly and a controller assembly, a motor and controller integrated heat dissipation scheme is adopted, forced air cooling heat dissipation is conducted on the controller through a motor integrated fan, the design of a cooling system is simplified, and the power-to-weight ratio is effectively increased. And meanwhile, the motor controller and the motor adopt coaxial equal-outer-diameter design, and the characteristics of high power density and high volume density are very suitable for being applied to an eVTOL aircraft electric propulsion system.

The invention discloses zinc ion battery electrolyte as well as a preparation method and application thereof, and belongs to the technical field of ion battery electrolyte. According to the preparation method disclosed by the invention, the coumarin derivative is added into the basic zinc salt solution, so that the uniform deposition of zinc ions can be promoted at a low temperature of-20 DEG C or below, the formation of dendritic crystals is remarkably reduced, and a stable protective layer is formed on the surface of the zinc anode, and the protective layer can maintain high reversibility of the battery at a normal temperature, and also can be used for preparing a lithium ion battery. And the stability can be kept in a low-temperature environment, so that the battery can show excellent electrochemical performance under different temperature conditions, and the technical problem of the electrochemical performance of the water-based zinc ion battery (ZIBs) in the low-temperature environment is solved.

The invention discloses a composite positive electrode material applied to an all-solid-state lithium-sulfur battery. The composite positive electrode material comprises elemental sulfur as an active substance, and a high-temperature and high-ionic-conductivity sulfide solid electrolyte as an ionic conductive agent for conducting lithium ions; and the conductive carbon material is used as an electronic conductive agent for conducting electrons. The mass ratio of the elemental sulfur to the conductive carbon material to the sulfide solid electrolyte can be 1: 1: 2. The volume expansion of the active substance sulfur in the obtained composite positive electrode is small, the ion / electron path in the composite positive electrode is excellent, and the assembled all-solid-state battery is high in safety, good in cycle stability and high in energy density and power density.

The invention belongs to the technical field of hydrogen bond organic framework materials, and relates to a three-component hydrogen bond organic framework material as well as a preparation method and application thereof, the chemical formula is {C26H21O12P4. (CH6N3). (C10H12N4). (H2O)} n, and n is a positive integer. A structural unit belongs to a triclinic system, a space group is P-1, a molecular formula is C37H41N7O13P4, and each repeating unit comprises a water molecule, a G < + > cation, a DBpy < 2 + > cation and a H5TPE < 3-> molecule; amino groups on G < + > cations, amino groups on DBpy < 2 + > cations, deprotonated HPO3-groups in H5TPE < 3-> molecules and unprotonated phosphonic acid groups have a synergistic effect, and water molecules form a two-dimensional hydrogen bond network. According to the three-component strategy, the chemical and structural diversity of HOFs is greatly expanded, and the material performance is remarkably improved.

In order to solve the problems of small torque density, large vibration and noise and the like of an axial magnetic flux permanent magnet motor, the utility model provides a three-stator disc and double-rotor disc type axial magnetic flux permanent magnet motor, which comprises a first stator disc, an upper rotor disc, a second stator disc, a lower rotor disc and a third stator disc which are sequentially distributed along the axial direction, the upper rotor disc consists of an upper rotor iron core, and a first permanent magnet group and a second permanent magnet group which are fixedly connected to two axial sides of the upper rotor iron core; the lower rotor disc is composed of a lower rotor iron core, and a third permanent magnet group and a fourth permanent magnet group which are fixedly connected to two axial sides of the lower rotor iron core; the circumferential dislocation included angle between the first permanent magnet set and the second permanent magnet set is theta, the circumferential dislocation included angle between the third permanent magnet set and the fourth permanent magnet set is theta / 2, through the structural arrangement, the peak values and valley values of torque ripples and cogging torque ripples of the two rotors are superposed, the overall output torque ripple and cogging torque are effectively reduced, vibration and noise are reduced, and the service life of the motor is prolonged. And the safety, stability and reliability of operation are improved.

The utility model discloses a power module and a vehicle. The power module comprises a heat radiation base plate, a circuit board, a power semiconductor chip and a housing. The number of the circuit boards is six, and the six circuit boards are arranged on one side of the heat dissipation bottom plate in the thickness direction at intervals. A power semiconductor chip is arranged on one side, deviating from the heat dissipation bottom plate, of each circuit board; the shell is an insulating part and comprises a shell body, and the shell body and the circuit boards are arranged on the same side in the thickness direction of the heat dissipation bottom plate and surround the six circuit boards. According to the power module, the power module is stable and reliable, the power density is high, the size can be effectively reduced, the cost is reduced, and the service life is prolonged.

The invention discloses a high-performance sodium-ion battery hard carbon negative electrode material and a preparation method thereof, and the preparation method comprises the following steps: uniformly mixing a carbon source precursor with metal chlorate, carrying out a catalytic carbonization reaction at 400-600 DEG C, and after the reaction, carrying out acid pickling and water washing to obtain a solid A; carrying out acid pickling and water washing on the solid A until the solid A is neutral, and carrying out microwave-assisted heat treatment at 1100-1500 DEG C to obtain a solid C; and crushing the solid C and carrying out chemical vapor deposition treatment to finally obtain the high-performance sodium-ion battery hard carbon negative electrode material. The hard carbon material prepared by the method has the advantages of abundant micropore structures, short-distance tight arrangement of layer structures, proper carbon layer spacing and low external specific surface area, and is suitable for a hard carbon negative electrode material of a high-energy and high-power-density sodium ion battery.

The invention relates to the technical field of current collectors, in particular to a diversion method of a functional current collector. The composite carbon nanotube is obtained by sequentially carrying out oxidation treatment, acylating chlorination treatment, modification treatment, amination treatment and graft polymerization treatment on a multi-wall carbon nanotube. Uniformly mixing the PET resin, the composite carbon nanotubes, a surfactant and a coupling agent, and carrying out standing, melt extrusion, tape casting, sheet casting treatment and two-way stretching to obtain the PET base film. The preparation method comprises the following steps: sequentially sputtering a copper layer on the surface of a PET (Polyethylene Terephthalate) base film, carrying out water electroplating on the copper layer, then coating the surface of the copper layer with an active substance, and then directly dipping a conductive adhesive solution in a lug position which is not plated with copper to obtain a pole piece; and stacking a plurality of pole pieces together, and inserting a current collector at the center of the stack to obtain the functional current collector. The functional current collector prepared by the method has good conductivity and mechanical property, so that the functional current collector has a wide application prospect in the technical field of current collectors.

An integrated electric wheel with a cooling function comprises a hub motor with a cooling water channel, a planetary reducer connected with a rotating shaft of the hub motor, a hub connected with the output end of the planetary reducer and a brake fixed to the hub, and is characterized in that the cooling water channel in the hub motor extends forwards to the periphery of the planetary reducer; and the planetary reducer is circularly cooled, and an oil guide assembly for collecting oil liquid thrown out in the circumferential direction and conducting lubricating and heat dissipation on the planetary reducer is assembled on the planetary reducer. Lubricating and radiating efficiency of parts close to the center of the speed reducer is effectively improved, temperature rise and part abrasion in the speed reducer are slowed down, the probability of abnormal transmission caused by bearing sintering and gear abrasion due to high temperature is effectively reduced, transmission reliability of the planetary speed reducer is improved, and the service life of the planetary speed reducer is prolonged. Integrated optimization of multiple structures of the electric wheel is formed, the integration degree is improved, whole vehicle arrangement is facilitated, the power density of the electric wheel is improved, and the cruising ability of the electric wheel is improved.

The invention discloses a membrane electrode, a preparation method thereof and a fuel cell, the membrane electrode comprises a catalyst layer and a proton exchange membrane, the catalyst layer comprises an anode catalyst layer and a cathode catalyst layer, and the anode catalyst layer and the cathode catalyst layer are respectively arranged on two sides of the proton exchange membrane; the catalyst layer and the proton exchange membrane are both doped with phosphoric acid. By macroscopically regulating and controlling the PA content of the catalyst layer and the proton exchange membrane in the membrane electrode, more three-phase reaction interfaces are constructed, so that the Pt catalyst can be fully utilized, and unnecessary migration of PA is reduced, thereby avoiding the phenomenon of acid flooding, ensuring sufficient PA in the proton exchange membrane to provide sufficient proton conductivity, and improving the proton exchange efficiency. And the power density of the fuel cell is further improved.

The invention belongs to the technical field of direct-current converters, and provides a direct-current converter with ultrahigh voltage gain and a control method thereof, and the main scheme is that the direct-current converter comprises a direct-current input source, an input inductor, a three-winding coupling inductor, a first switching tube, a second switching tube, a first diode, a second diode, a third diode and a fourth diode, a first clamping capacitor, a second clamping capacitor, a third clamping capacitor, a first output capacitor, a second output capacitor, a third output capacitor, a load and a three-winding coupling inductor are arranged, and a first winding, a second winding and a third winding form three windings and are integrated through a single magnetic core. According to the invention, ultrahigh output voltage gain can be realized, almost zero input current ripple can be realized, the semiconductor device can realize soft switching, the number of the devices is small, the cost is low, and the device is suitable for being applied to power conversion between a photovoltaic new energy power generation unit and a high-voltage direct-current bus.