31results about How to "Solve uneven flow" patented technology

The embodiment of the invention provides a resonant switching circuit. The resonant switching circuit comprises at least two resonant switching circuit units, wherein the resonant switching circuit units are staggered and connected in parallel, and magnetic devices in the resonant switching circuit units are alternately and magnetically integrated on the same magnetic core. As the magnetic devices integrated on the same magnetic core can exert a magnetic path coupling effect, a self current-balancing effect can be produced by currents on circuit branches of different phases, so that the current balance of the resonant switching circuit units in the resonant switching circuit is realized, and the volume of a power supply is reduced due to the integration of the magnetic devices.

The invention discloses a parallel IGBT power unit. The parallel IGBT power unit comprises an upper bridge IGBT module and a lower bridge IGBT module. Each IGBT module includes at least two IGBT modules which are connected in parallel, and further comprises an upper busbar and a lower busbar which are correspondingly connected with the two IGBT modules. The upper busbar is provided with a first leading-out terminal for connecting with a first main busbar and a first capacitor connecting terminal for connecting with a capacitor. The lower busbar is provided with a second leading-out terminal for connecting with a second main busbar and a second capacitor connecting terminal for connecting with a capacitor. According to the parallel IGBT power unit, the two IGBT modules and the two busbars which have identical structures and are correspondingly connected with the modules respectively are adopted; the leading-out terminals for connecting with the main busbars and the capacitor connecting terminals for connecting with the capacitors on the busbars are in conductive connection with docking connecting terminals and capacitor connecting terminals at corresponding positions of the IGBT modules of corresponding busbars by using copper bars in identical lengths; and since busbars connecting the IGBTs are identical in length, the current-sharing performance of the parallel IGBT modules on the busbars is guaranteed, and a problem of uneven current during parallel connection of the IGBTs is solved.

The invention provides a dust removal airway comprising an airflow channel, an air distributing hole, an exhaust hole, upper baffle plates, lower baffle plates and a dust discharge hole, wherein the air distributing hole and the exhaust hole are formed in the positions at two ends of the airflow channel; the upper baffle plates are vertically arranged above the inner wall of the airflow channel; the lower baffle plates are vertically arranged and the dust discharge hole is vertically formed below the inner wall of the airflow channel; the dust discharge hole is formed below the upper baffle plates; the air distribution hole and the exhaust hole are conical; the large ends of the conical air distribution hole and the exhaust hole are communicated with the airflow channel. The dust removal airway disclosed by the invention comprises a plurality of upper baffle plates and lower baffle plates which are arranged at intervals; the even zigzag dust removal airway is provided, and the air distribution hole and the exhaust hole are formed in conical shapes, so that air can be effectively and evenly distributed.

The invention relates to a fiberglass/PP composite fiber cloth assisting resin transfer molding (RTM) process method and a molding mold. The adopted mold comprises a lower mold, foam, a sealing rubberstrip, a glue injection opening, an upper mold and a vacuumizing opening. In a process, fiberglass and PP material are woven into composite fiber cloth according to required gram weight first, then needed carbon fibers or fiberglass cloth are/is laid on the surface of a mold cavity, then the fiberglass/PP composite fiber cloth is laid, the foam processed through computer numerical control (CNC) is put in, and then according to symmetrical laminates, fiberglass/PP composite fiber cloth, carbon fibers or fiberglass cloth are laid. Finally, mold assembly, vacuumizing and resin injection are conducted, after product solidification, the molding mold is opened, and a product is taken. According to the fiberglass/PP composite fiber cloth assisting resin transfer molding (RTM) process method andthe molding mold, the fiberglass/PP composite fiber cloth is adopted, PP felt and the foam are attached during material laying, the PP felt is fluffy, thus channels are provided for resin flowing, theproblem of uneven resin flowing on the surface of the foam is solved, the foam does not need slotting or punching, and machining cost of the foam is lowered greatly.

The invention discloses a current equalizing control method of double BOOST circuits of a two-stage photovoltaic power generation system. The currents of the two BOOST circuits are sampled in real time through a system. The input current of one BOOST circuit serves as the reference, a duty ratio increment is worked out through the two BOOST input currents by means of a PI regulator, the on-off time (namely the duty ratio) of a switching device of the other BOOST circuit is corrected with the increment, and thus the currents of the two BOOST circuits are made equal. The problem that the currents of the two BOOST circuits running in parallel connection are unequal is solved, and thus the problems that the service life of a device with an overcurrent circuit becomes shorter, and an inverter is shut down due to overcurrent are avoided.

The invention relates to a precision spraying valve with a piezoelectric wafer serving as a driving source. The precision spraying valve comprises a cavity, a one-way valve, the piezoelectric wafer, a needle head, a gas hood and the like. The piezoelectric wafer serving as the driving source presses spraying materials into the needle head, compressed gas in the gas hood descends to disperse the spraying materials into tiny liquid beads to be deposited on the surface of a workpiece. Since a traditional needle valve is not used for controlling spraying or spraying stop of the spraying materials, when the precision spraying valve is used for precision spraying, large edge allowance caused by factors such as eccentricity and form and location tolerance of the needle valve is eliminated.

The invention discloses a linear voltage-stabilizing power supply which comprises a current-sharing control circuit. The current sharing control circuit comprises at least one current sharing controlunit, and each current sharing control unit comprises a driving voltage adjusting circuit, a linear voltage stabilizing circuit and a feedback circuit, wherein the feedback circuit is used for feedingback the voltage of a current sampling resistor of the linear voltage stabilizing circuit to the driving voltage adjusting circuit; the driving voltage adjusting circuit adjusts the current of the analog control signal Vctrl input into the current sharing control unit according to the voltage value of the current sampling resistor and then outputs the adjusted current to the linear voltage stabilizing circuit, so that the output power of the linear voltage stabilizing circuit is adjusted by adjusting the voltage of the current sampling resistor. Due to the fact that the output power of the linear voltage stabilizing circuit of each current sharing control unit can be adjusted, the problem that the linear voltage stabilizing power supply is uneven in current is solved, stability of the linear voltage stabilizing power supply is improved, and the service life of the linear voltage stabilizing power supply is prolonged.

The embodiment of the invention provides a battery system and an electric vehicle, and relates to the technical field of battery application. The battery system comprises at least two battery branchesand a controller, wherein each battery branch comprises a battery and a regulating unit, each battery branch is connected in parallel with each other, the battery in each battery branch is connectedin series with the regulating unit in each battery branch, and the controller is electrically connected with the regulating unit in each battery branch; The controller is used for regulating the resistance value of the regulating unit in each battery branch according to a pre-established mathematical model, thereby regulating the output current of each battery branch. The battery system and the electric vehicle provided by the embodiment of the invention can solve the problem that the output current distribution of each branch of the battery system is unbalanced.

The invention relates to an inverter heat-radiating device with air duct partition plates, which belongs to the field of photovoltaic inverter thermal design. The inverter heat-radiating device with the air duct partition plates comprises a centrifugal fan, a fan mounting plate, a flow equalizing air duct, radiator air ducts, radiators and a mounting plate. According to the inverter heat-radiatingdevice, six IGBT of an inverter are separately arranged in three different cavities according to A, B and C phases, and the inverter heat-radiating device guarantees that the temperature of the IGBTsdoes not exceed a limit in the case of using one centrifugal fan. Meanwhile, the invention designs an air duct, which ensures air flow entering the three cavities are even, and the difference betweenthe highest temperature of the A-phase, B-phase and C-phase IGBTs is less than 2 DEG C, so that the temperature of each IGBT group is balanced and the problem of uneven current of the IGBTs is solved.

The invention discloses a test method, a test system and test equipment. The test method comprises the following steps: dividing source data into a plurality of groups, wherein the source data are used for testing a plurality of resources, and the source data that test the same resource are divided into the same group; generating grouping information based on the source data in the same group; generating a plurality of sequences based on the plurality of groups; and taking the grouping information and the plurality of sequences as configuration information, sending the configuration information to a plurality of terminals together with a test instruction, wherein the test instruction is used for instructing the plurality of terminals to test the plurality of resources according to different sequences in the plurality of sequences and according to the grouping information.

The invention relates to the technical field of gardens, and discloses a modular intelligent garden management and cultivation system, which comprises a planning module, an Internet of Things landing module and a digital operation and maintenance module, the planning module comprises a user module, a work module, a work constraint and verification module, a design analysis engine module, a first AI learning training engine module and a design standard database module, and the user module comprises a platform registration/login module and a user labeling module. According to the modular intelligent garden management and cultivation system, through platform-level accurate operation and maintenance management, the problems of low efficiency, high cost and poor effect of traditional extensive management can be significantly solved; the problem of unbalanced water pressure and flow of an urban garden irrigation water supply network is solved through effective deployment of the Internet of Things intelligent terminal and scientific scheduling of digital operation and maintenance; the platform is combined with constraints such as vegetation characteristics and maintenance standards, and accurate maintenance and management can be carried out for different vegetation in different periods.

The invention provides a method for determining an oil outlet position of a double rectangular cavity static pressure sliding bearing; during the operation process of the static pressure sliding bearing, due to the influence of the position of the oil outlet, the shape and rotary speed of an oil chamber, the flow rate of the hydraulic oil flowing out of each oil sealing edge is different, so the operation stability of the static pressure equipment is reduced. In order to balance the flow of the oil sealing edge, reduce the influence of the rotary speed on the flow distribution and improve thebearing performance and stability of the static pressure sliding bearing, the invention provides the method for determining the oil outlet position of the double rectangular cavity static pressure sliding bearing. The method comprises the following steps of: step A: establishing a single rectangular cavity to simplify the flow rate vector; step B: establishing a rotary speed vector of a turntable,and synthesizing with the hydraulic oil flow rate vector to obtain a resultant velocity; step C: analyzing the flow change of each oil sealing edge by the resultant velocity, and performing integralsum calculation; step D: obtaining a liquid resistance ratio from the flow rate ratio, wherein the distance from the oil outlet to the oil sealing edge is larger, and calculating the coordinates of the oil outlet by the integral ratio method; and step E: calculating the position of the oil outlet of another oil chamber by the geometric method.

The invention discloses a parallel resonant converter and a power supply. The parallel resonant converter comprises at least two paths of parallel resonant converters, and the at least two paths of parallel resonant converters share a resonant capacitor and a resonant inductor. According to the invention, a problem that current sharing does not exist in the parallel resonant converter in the priorart is solved so that natural current sharing is realized between the two resonant converters.

The invention relates to a current sharing method of a centralized control type interleaving parallel circuit, which comprises the following steps of: setting the duty ratio of a first parallel circuit in the interleaving parallel circuit as a first duty ratio, and setting the duty ratio of a second parallel circuit in the interleaving parallel circuit as a second duty ratio; based on the first duty ratio; and the ratio of the voltage difference value of the input voltage sampled at the zero crossing point of the triangular carrier wave of the first parallel circuit and the input voltage sampled at the periodic value to the bus voltage value of the interleaved parallel circuit is set as a second duty ratio compensation amount which ensures that the currents of the two parallel circuits are equal when one switching period is ended. The invention further relates to a computer readable storage medium and a centralized control type interleaving parallel circuit. According to the invention, the problem of non-uniform current between circuits can be solved in a low-cost and easy-to-implement manner, and the sine degree of the second parallel circuit is improved.

The invention discloses an LLC resonant conversion circuit and an LLC resonant converter, the LLC resonant conversion circuit comprises an input end, a first half-bridge LLC circuit, a second half-bridge LLC circuit, an output end, a conversion device, a first driving end and a second driving end, the first half-bridge LLC circuit and the second half-bridge LLC circuit are connected in parallel between the input end and the output end, the conversion device is respectively connected with the resonant cavities of the two half-bridge LLC circuits and is used for connecting the two resonant cavities in series, and the two driving ends input different driving signals in a crossed manner, so that the current of the resonant cavity of each half-bridge LLC circuit passes through the resonant cavity of the other half-bridge LLC circuit, and the current of the resonant cavities of the two LLC circuits is equal; rectified output currents of the two half-bridge LLC circuits are also equal, so that the problem of non-uniform parallel currents can be solved.