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1871results about How to "Reduce loss" patented technology

Paper money temporary storage module and reel rotating speed control method thereof

The invention relates to a paper money temporary storage module and a reel rotating speed control method thereof. The paper money temporary storage module comprises a large reel driven by a first power motor, a small reel driven by a second power motor, a coiling tape, a first coded disc, a second coded disc, a first sensor, a second sensor and a microcontroller, wherein two ends of the coiling tape are respectively fixed on the large reel and the small reel and the coiling tape is retracted and wound between the large reel and the small reel; the first coded disc is fixed on a rotating shaft of the large reel; the second coded disc is fixed on a rotating shaft of the small reel; the first sensor is arranged corresponding to the first coded disc and is used for monitoring the rotating angle of the large reel; the second sensor is arranged corresponding to the second coded disc and is used for monitoring the rotating angle of the small reel; and the microcontroller is used for calculating the length of the coil tape released by the small reel when the large reel rotates for a circle according to output signals of the first sensor and the second sensor and further calculating the current radius of the large reel, and thus angular velocities of the large reel and the small reel are controlled and the linear velocity of the large reel is enabled to be consistent with that of the small reel.
Owner:GRG BAKING EQUIP CO LTD

Starting circuit for switching power supply

The invention discloses a starting circuit for a high-voltage and wide-input range switching power supply. The starting circuit comprises a voltage-sharing part, a voltage stabilizing part, a current source part and an output circuit, wherein the voltage-sharing part consists of at least two stages of voltage-sharing circuits which are connected in series; the voltage stabilizing part is formed by connecting at least two stages of voltage stabilizing circuits in series; the current source part is formed by connecting at least two stages of current source circuits in series; an input source voltage is connected to the two ends of each of the voltage-sharing part and the voltage-stabilizing part which have the same stage; voltage-sharing points at which every two stages of voltage-sharing circuits are connected in series are connected with series-connection points of the voltage stabilizing circuits of the corresponding stages; the input end of the current source part is connected with the anode of the input source voltage; the control ends of each stage of current source circuits are connected with the voltage stabilizing output ends of the voltage stabilizing circuits of the corresponding stages; the output end of the current source part is connected with the input end of the output circuit; the output end of the output circuit is the output end of the starting circuit; after the input source voltage passes through the voltage-sharing part, shared voltages are output are input into each stage of current source circuits by the voltage stabilizing part to control the input source voltage sharing of each stage of current source circuits; or a switching-off circuit can be connected to switch the starting circuit off when the switching power supply works normally, so loss is reduced.
Owner:MORNSUN GUANGZHOU SCI & TECH

Step wave pulse width modulation method based on nonlinear programming

The invention relates to a step wave pulse width modulation method based on nonlinear programming. The step wave pulse width modulation method comprises the following steps of: correspondingly calculating the number of sub-modules in a part to be added or cut according to increase or decrease of a modulation degree so as to reach required alternating current voltage output; secondly, establishing a nonlinear programming mathematical model of the modulation method with a goal that the approximate error of a fundamental wave component in the step wave outputted by a current converter is minimum relative to a given modulation wave on the basis of a theoretically output step waveform Fourier transform result by selecting an initial value of a triggering angle; finally obtaining the solution of the triggering angle under a corresponding level number and modulation degree. The step wave pulse width modulation method based on the nonlinear programming, disclosed by the invention, overcomes defects of a specific sub-harmonic elimination method that calculation amount is huge and on-line real-time calculation cannot be carried out. A switch device is only switched on and off once in one cyclic wave, the remarkable advantage of small switching loss is achieved. The step wave pulse width modulation method based on the nonlinear programming, disclosed by the invention, has better expandability, can theoretically finish trigger impulse control tasks of voltage source current converters with any quantity of levels, has stronger transportability, is suitable for modularized multi-level converters and is also suitable for cascaded H-shaped bridge type voltage source current converters with a large quantity of levels.
Owner:ELECTRIC POWER RESEARCH INSTITUTE, CHINA SOUTHERN POWER GRID CO LTD +1

Modular multilevel converter (MMC) circulating current suppression method

A modular multilevel converter (MMC) circulating current suppression method is provided. The invention belongs to the technical field of electrical engineering, specifically relates to a suppression method for suppressing internal circulating current of an MMC, and solves problems of incompatibility with single phase and three phase systems, poor circulating current suppression capability and a complicated control method in conventional MMC circulating current suppression methods. According to the MMC circulating current suppression method, a wave trap is used for acquiring secondary harmonic signals in phase current; the harmonic signals in the phase current are subtracted from the average current of the phase current so that average current signals of an upper bridge arm and a lower bridge arm in which secondary harmonic waves are subtracted are acquired; the average current signals of an upper bridge arm and a lower bridge arm in which secondary harmonic waves are subtracted is taken to do subtraction with a reference current, and thus secondary harmonic signals of the circulating current is acquired; a proportional resonant controller is used for performing current tracing on the secondary harmonic waves of the circulating current, and thus voltage compensation signals are acquired; the compensation signals are processed and then are given back to sub-modules of the upper bridge arm of the MMC, and thus circulating current suppression is realized. The MMC circulating current suppression method is suitable for the technical field of electrical engineering.
Owner:HARBIN INST OF TECH

Wireless internet congestion control method based on multi-path load balancing and controller thereof

The invention discloses a wireless internet block control method and a controller therefore based on multipath load balance and relates to the technical field of wireless communication. On the basis of a multipath scheme, an effective grouping transmission distribution strategy is carried out at a sending end to solve grouping disorder (Out-Of-Order, OOO) problems. Parameters are shared among different logistic layers. A multipath shunt strategy is combined, and the block judge of the parameter information of the network layers is combined. In multipath, the ordered grouping distributing strategy of data is guaranteed to enhance the TCP performance of the wireless internet. When a source node detects that a time clock is time out or repeated ACK is not roused by block, a TCP error control module controls a message segment sending module for resending messages. Otherwise, a TCP block control strategy and a block control strategy basing on the prepared path distributing and grouping are adopted for relieving the block. The wireless internet block control method and the controller therefore basing on multipath load balance can be widely applied to wireless Ad hoc network, wireless Mesh network, wireless sensor network, etc.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Low-loss microstrip patch frequency scanning antenna array capable of scanning by large angle in limited bandwidth

InactiveCN101814657AReduce lossImprove performanceAntenna arraysAntenna earthingsPhysicsMicrostrip patch antenna array
The invention discloses a low-loss microstrip patch frequency scanning antenna array capable of scanning by a large angle in a limited bandwidth. The low-loss microstrip patch frequency scanning antenna array comprises an E-plane bend waveguide, a metal floor, a medium base plate, a waveguide gap microstrip patch mixed feeding structure and microstrip patch units, wherein one end of the E-plane bend waveguide is provided with a feeding port, and the other end of the E-plane bend waveguide is provided with a waveguide port which is connected with matched load; the metal floor is arranged on the E-plane bend waveguide; rectangular gaps are formed on the metal floor; the medium base plate is arranged on the metal floor; two rows of the microstrip patch units are arranged on the medium base plate; the number of each row of the microstrip patch units is as same as that of the gaps; all the microstrip patch units form the microstrip patch antenna array; a coupling microstrip patch is arranged on the medium base plate corresponding to each gap, on the medium base plate; microstrip transmission lines are symmetrically connected with the two sides of each coupling microstrip patch respectively; and the ports of the microstrip transmission lines are connected with the corresponding microstrip patch units respectively. The low-loss microstrip patch frequency scanning antenna array has the advantages of obviously reducing the loss of a frequency scanning slow wave line and improving the performance of the frequency scanning antenna.
Owner:NANJING UNIV OF SCI & TECH

Control method for variable frequency air conditioner

ActiveCN104214886AReduce lossHigh frequency conversion efficiencySpace heating and ventilation safety systemsLighting and heating apparatusField weakeningMultiple target
The invention provides a control method for a variable frequency air conditioner. The control method includes the following steps of obtaining multiple target direct-current bus voltages according to the voltage of a direct-current bus in the variable frequency air conditioner, wherein each target direct-current bus voltage corresponds to one operating point; detecting the current voltage of the direct-current bus, carrying out PFC control so as to improve the current voltage of the direct current bus to the corresponding target direct-current bus voltage, carrying out field weakening control and vector control on a compressor according to the corresponding target direct-current bus voltage and the rotation speed instruction of the compressor of the variable frequency air conditioner, calculating the variable frequency efficiency, corresponding to each operating point, of the variable frequency air conditioner according to the running condition of the compressor so as to obtain the optimal variable frequency efficiency of the variable frequency air conditioner, and controlling the variable frequency air conditioner to operate according to the direct-current bus voltage corresponding to the optimal variable frequency efficiency. The control method for the variable frequency air conditioner is simple in algorithm, small in operation amount, capable of reducing operation losses and improving operating efficiency, and low in implementation cost.
Owner:GD MIDEA AIR-CONDITIONING EQUIP CO LTD

High-voltage pulse power supply for plasma sewage treatment system

ActiveCN103219913AReduce design difficultyReduce lossPower gridPlasma reactor
The invention discloses a high-voltage pulse power supply for a plasma sewage treatment system. The high-voltage pulse power supply comprises a power frequency rectifying and filtering circuit, a first-stage boosted circuit, a second-stage boosted circuit and a voltage coupling circuit. The power frequency rectifying and filtering circuit is connected with a municipal power grid to convert power frequency alternating current into direct current. An input end and an output end of the first-stage boosted circuit are respectively connected with an output end of the power frequency rectifying and filtering circuit and an input end of the second-stage boosted circuit to achieve the functions of boosting and rectifying and filtering. The second-stage boosted circuit is boosted again and outputs stable high-voltage direct current and stable high-voltage alternating current. The voltage coupling circuit couples and superimposes the alternating current and the direct current and loads the alternating current and the direct current to equivalent loads of a plasma reactor. According to the high-voltage pulse power supply for the plasma sewage treatment system, the traditional method that two independent alternating-current power supply and direct-current power supply are used for carrying out coupling discharging is changed, the number of needed hardware components is decreased to a great extent, space and cost are saved, loss is reduced, and reliability and stability of a power supply system are improved.
Owner:SOUTHEAST UNIV

Closed type automatic industry-parts cleaning oil-sealing device

The invention relates to a fully-enclosed automatic industrial component cleaning and oil sealing machine, and is characterized in that the machine comprises a cleaning bin, a main transmission system, a refrigeration system, an air passage drying reclaiming system, a liquid storage tank and a grease box, a filter, a distillation reclaiming system or a vacuum distillation reclaiming system, a carbon adsorption reclaiming system, as well as an ultrasonic generating device. The machine has the advantages that full-automatic control is realized, and the cleaning and the oil sealing are performed without the need of manpower, so that the labor intensity is reduced; the problems of easy flammability, insecurity and poor labor conditions caused by using gasoline, kerosene and alkaline solution as cleaning liquid are avoided; furthermore, the machine has the characteristics of an fully-enclosed structure and the vacuum distillation reclaiming system, thereby repeatedly utilizing a cleaning solvent, reducing the loss of the cleaning solvent, preventing people from direct contact with the cleaning solvent, and reducing environmental pollution and human body injuries; therefore, an organic solvent can be repeatedly used; meanwhile, the cyclic cleaning is performed by utilizing a combination of chemical force and various types of physical force, thereby enhancing the cleaning efficiency.
Owner:田飞

Balanced judgment and supplementary device of energy transfer type battery pack and method thereof

The invention relates to a balanced judgment and supplementary device of an energy transfer type battery pack and a method thereof, which are mainly used on occasions when numerous batteries are connected in series for use in industry. The device comprises balancing modules and a measurement and control module, wherein the balancing modules are connected in turns, are connected with each single battery, and charge the single battery by using the energy of the battery pack or the energy of an external power supply; the measurement and control module is connected with the battery pack and each single battery therein, and measures and compares the single battery. The method comprises the following steps of: measuring and controlling the total voltage of battery packs connected in series and the voltage of each single battery; calculating the average voltage of the batteries of the battery packs connected in series; sending starting/stopping signals; and making the voltage of the single battery approach to the average voltage of the battery packs. The device and the method have the advantages of having the function of ensuring the voltage balancing, which is performed in a mode of energy transfer, of the single batteries of the battery packs connected in series in use, having small losses, and being favorable to be applied to middle or large-capacity battery packs.
Owner:武汉长海电力推进和化学电源有限公司
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