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56results about How to "Improve harmonics" patented technology

Parallel current mode control

A method and apparatus to implement parallel current mode control that is suitable for digital and analog implementation. A duty cycle algorithm is composed of a voltage term and a parallel current term which depends on the inductor current change between the inductor current value at the beginning of a switching cycle and the reference inductor current value at the end of that switching cycle. Parallel current mode control can be applied to all DC-DC converters, including both non-isolated and isolated topologies. It can also be applied to AC-DC converters with power factor correction.
Owner:DIALOG SEMICONDUCTOR INC

Method and Apparatus for use in Improving Linearity of MOSFETS using an Accumulated Charge Sink-Harmonic Wrinkle Reduction

ActiveUS20120267719A1Improving nonlinear responseImprove harmonicsSolid-state devicesPulse techniqueMOSFETHarmonic
A method and apparatus for use in improving linearity sensitivity of MOSFET devices having an accumulated charge sink (ACS) are disclosed. The method and apparatus are adapted to address degradation in second- and third-order intermodulation harmonic distortion at a desired range of operating voltage in devices employing an accumulated charge sink.
Owner:PSEMI CORP

Parallel active filter based on modularization multi-level converter and control method of parallel active filter

The invention discloses a parallel active filter based on a modularization multi-level converter and a control method of the parallel active filter and belongs to the technical field of power harmonic suppression in a medium-high voltage high-power occasion. The problem that an existing parallel active filter cannot carry out harmonic combination compensation effectively, so that power distribution network electric energy quality is poor is solved. The filter comprises the modularization multi-level converter, a current transformation unit, a harmonic current detecting unit, a current controller, a capacitor C and a power grid electric reactor LS. The modularization multi-level converter is of a half-bridge-type topological structure, and an upper bridge arm and a lower bridge arm of the modularization multi-level converter respectively comprise n submodules SMn. According to the control method, a carrier phase-shifting modulation method is used, so that under the same switch frequency, equivalent switch frequency is high, switching loss is reduced, meanwhile, a capacitive coupling voltage sharing and ring current suppression strategy is used, and capacitor voltages and direct current bus voltages of the submodules are kept stable. The parallel active filter is used for harmonic suppression of a power grid.
Owner:HARBIN INST OF TECH

Method and Apparatus for use in Improving Linearity of MOSFETs Using an Accumulated Charge Sink-Harmonic Wrinkle Reduction

ActiveUS20160064561A1Improving nonlinear responseImprove harmonicsSolid-state devicesElectronic switchingMOSFETHarmonic
A method and apparatus for use in improving linearity sensitivity of MOSFET devices having an accumulated charge sink (ACS) are disclosed. The method and apparatus are adapted to address degradation in second- and third-order intermodulation harmonic distortion at a desired range of operating voltage in devices employing an accumulated charge sink.
Owner:PSEMI CORP

Method for tracing maximum power point of photovoltaic miniature grid-connected inverter

The invention relates to a method for tracing a maximum power point of a photovoltaic miniature grid-connected inverter. When the output power of a photovoltaic cell is high, the traditional continuous operating mode and a maximum power point tracing method are adopted; and when the output power of the photovoltaic cell is low, intermittent operating mode is adopted, namely operation is continuously performed for a plurality of periods with set power, then operation is stopped for a while to store energy to a capacitor, and simultaneously maximum power point tracing is performed with voltage change rate in the energy storage period, so as to ensure that the photovoltaic cell is operated at maximum power point voltage. The method can effectively solve the problems that the efficiency of a traditional inverter is low when the illumination intensity is low, grid-connected current harmonic wave is large, and the like.
Owner:上海岩芯电子科技有限公司

Feedforward decoupling control method based on three-phase two-arm tri-level active power quality compensator

The invention discloses a feedforward decoupling control method based on a three-phase two-arm tri-level active power quality compensator. For the purpose of realizing reactive compensation, negative sequence compensation and harmonic compensation, one two-input and two-output coupling system is decoupled into two independent single-input single-output systems, thus quickly tracking current and improving reliability of the system; and a corresponding PWM (pulse width modulation) method is adopted to drive a switching tube to acquire an expected current. The feedforward decoupling deadbeat control method based on the three-phase two-arm tri-level active power quality compensator can be used to realize complete compensation and inhibition of the negative sequence and harmonic waves of the systems.
Owner:HUNAN UNIV

Integrated filter inductance transformer

The invention disclosed an integrated filter inductance transformer, comprising a primary winding, a secondary winding, and LC resonant circuits of each winding characteristic harmonics, wherein the reactance L of the resonant circuits is a two-segment adverse-parallel symmetric interleaving winding which is wound with the primary winding and the secondary winding on the same iron core in a up-down symmetry manner. In the invention, the LC resonant circuits of each winding characteristic harmonics can eliminate the harmonic flux of the iron core, and prevent the harmonics from passing back, thereby realizing the function of filtering the primary winding harmonics; meanwhile, the transformer also has the function of reactive power compensation.
Owner:HUNAN UNIV +2

Control method of hybrid four-leg shunt active power filter

The invention relates to a control method of a hybrid four-leg shunt active power filter. In the method provided by the invention, a space vector control method is utilized as a core for calculation to obtain the base quantity of the output voltage reference value of legs, and a current hysteresis control method is utilized as a core for calculation to obtain the regulating quantity of the outputvoltage reference value of the legs. When the error of the reference current of the legs of the active power filter and the actual output current is smaller, the current hysteresis control is of no avail, and the active power filter is ensured to have higher control accuracy when the load harmonic content is small; when the error is larger, the regulating quantity obtained by calculation adds thebase quantity, and the active power filter is ensured to have quicker response speed when the load harmonic content is large. By utilizing the method, the adaptive ability of the four-leg active power filter can be improved, and the four-leg active power filter is ensured to well compensate the harmonic current and neutral current in the system under different harmonic conditions.
Owner:TALENT SCI & TECH CO LTD

Internal double-feed wind-driven generator

The invention relates to an internal double-feed wind-driven generator, which conveniently realizes high-voltage class. The internal double-feed wind-driven generator comprises a stator and a rotor, wherein the stator is provided with a star-connection stator winding and a delta-connection regulating winding; the stator winding is connected with an electric network side; the regulating winding is connected with a network side converter of a wind turbine current transformer; and a rotor winding is connected with a machine side converter of the wind turbine current transformer.
Owner:SHANDONG ELECTRIC POWER RES INST +1

Control circuit and method for step-down circuit

The invention discloses a control circuit for a step-down circuit. The control circuit includes a reference signal generating circuit and a ramp signal generating circuit. The reference signal generating circuit receives a sampling signal and a current reference signal characterizing the inductor current to generate a first reference signal. The ramp signal generating circuit receives the first current, and obtains a ramp signal by charging and discharging the first capacitor; the first reference signal or / and the first current is proported. Before the ratio adjustment, the ratio of the firstreference signal to the first current is k1; after the ratio adjustment, a second reference signal and a second current are respectively obtained, and, the ratio of the second reference signal to thesecond current is k2; the ratio of k2 to k1 is shown in the description, where D is the main power tube duty cycle of the buck circuit; the reference voltage including the second reference signal is compared with the ramp signal to generate a control signal for controlling the main switch of the buck circuit to be turned on or off. The control circuit is capable of optimizing harmonics in the buckinput current.
Owner:JOULWATT TECH INC LTD

Dielectric filter

InactiveCN111883886AImprove harmonicsHigh frequency rejection facilitatesWaveguide type devicesCapacitanceCapacitive coupling
The dielectric filter at least comprises two dielectric resonators, and each dielectric resonator comprises a body and a debugging hole; a sunken area is arranged between the two dielectric resonatorsto realize high-frequency suppression, the body is provided with at least one negative coupling hole, the negative coupling hole is arranged in a range corresponding to the sunken area, the cross sectional area of the negative coupling hole is smaller than the area of the sunken area, and the negative coupling hole is a blind hole. The sum of the depths of the blind hole and the recessed area isless than the thickness of the body and larger than the depth of the debugging hole, and the negative coupling hole is used for achieving capacitive coupling between the two dielectric resonators. Bymeans of the design of the recessed area, needed frequency is designed to be insensitive frequency, and unnecessary frequency (namely harmonic waves) is pushed away; the harmonic waves are far away from the normal working frequency (also called high-frequency suppression) of the dielectric filter as far as possible, so the dielectric filter is convenient for pushing away the harmonic waves and isbeneficial to realizing high-frequency suppression.
Owner:WUHAN FINGU ELECTRONICS TECH

Dual-mode dielectric filter and zero point adjustment method thereof

The invention provides a dual-mode dielectric filter and a zero point adjustment method thereof, the dual-mode dielectric filter comprises a first resonant cavity and a second resonant cavity, and further comprises a plurality of dual-mode dielectric blocks located between the first resonant cavity and the second resonant cavity, the surface of each dual-mode dielectric block is provided with a metal layer, a first coupling structure is arranged between the dual-mode medium block adjacent to the first resonant cavity and the first resonant cavity, a second coupling structure is arranged between the dual-mode medium block adjacent to the second resonant cavity and the second resonant cavity, and the binding face of each dual-mode medium block and the adjacent dual-mode medium block is a coupling face, corresponding coupling windows are etched on the two attached coupling faces, the coupling window on each coupling face comprises at least one first strip-shaped window, the center line of the first strip-shaped window in the length direction is parallel to the first central axis of the coupling face, and the projection of the first strip-shaped window on the first central axis is far away from the center of the coupling face. Harmonic waves can be improved.
Owner:WUHAN FINGU ELECTRONICS TECH

TE mode dielectric resonator device

ActiveCN105552496AEven by forceSolve the disadvantages of long-term stressResonatorsArchitectural engineeringDielectric resonator
The invention provides a TE mode dielectric resonator device. A limiting groove is arranged at the bottom of a cavity; the surface and the underside of a TE01 mode dielectric resonance rod are each provided with a clamping groove; an upper support base and a lower support base are respectively clamped on the clamping groove; the lower support base is clamped in the limiting groove; the top of the upper support base and the top of the cavity are horizontally collinear; a cover plate comprises an inner cover plate and an outer cover plate; a groove is arranged at the bottom of the outer cover plate; an elastic body is arranged in the groove; and the outer cover plate is installed on the inner cover plate through a connecting part. By being supported by the upper and lower support bases, a TE01 mode dielectric resonator is stressed uniformly; the long-term stressed disadvantage of the traditional TE01 mode dielectric resonator while being installed laterally and installed reversely can be solved; due to support through the upper and lower support bases, heat generated by the TE01 mode dielectric resonance rod can be effectively transferred to the cavity and the cover plate, such that heat dissipation of the cavity body is easily carried; and in addition, due to improvement of the cover plate, the problem that the cavity and a TE01 mode medium are in poor contact due to the machining tolerance can be solved.
Owner:SUZHOU ZIBO ELECTRONICS TECH CO LTD

Multiphase motor control system based on driving of multiphase matrix converter

The invention relates to a multiphase motor control system based on the driving of a multiphase matrix converter, which comprises the multiphase matrix converter composed of 3*3n two-way switch tubes to form a 3*3n switch matrix, the on and off of each of the switch tubes are controlled by trigger pulse signals sent by a controller, an input side is connected with a three-phase alternating-current power source, an output side is connected with a multiphase motor with the phase number of 3*n (n is a positive integer which is more than or equal to 2), and the multiphase matrix converter serving as a driving system of the multiphase motor matches with the multiphase motor. The multiphase motor control system has the advantages that compared with the prior art, the efficiency is higher, the whole control system guarantees the multiphase motor to be provided with high accurate speed control performance and four phase limit operation of the multiphase motor, is capable of feeding energy back to the power system, and greatly improves the efficiency of the system during the operation of the multiphase motor; and the influence of the system to the quality of the electric energy of the power system is greatly reduced, and factors such as harmonic wave and power are improved greatly, particularly when the multiphase motor operates in low load.
Owner:杭州锐方科技有限公司

Three-phase four-bridge-arm inverter random pulse position 3D-SVPWM control system and method thereof

The invention discloses a three-phase four-bridge-arm inverter random pulse position 3D-SVPWM control system and a method thereof, and belongs to the technical field of power electronics. The controlsystem uses a three-phase sine wave generator to generate three-phase sine waves to be transmitted to a 3D-SVPWM generator; a vector action time module calculates the action time of a working voltagevector according to the random number generated by a random number generator; a switch action time module calculates the action time of an upper switch tube and a lower switch tube of the three-phasefour-bridge arm inverter according to the obtained action time and transmits the action time to the 3D-SVPWM generator; and the 3D-SVPWM generator is used for generating a PWM control signal according to the received three-phase sine waves, the vector action time and the set switching period, and conducts the signal to an IGTB switch tube of the three-phase four-bridge-arm inverter topological structure through a wire. According to the method disclosed by the invention, under the condition that THD is not increased, the high-order harmonic waves at the switching frequency are dispersed withina certain range, so that the electromagnetic interference of the system is lowered.
Owner:SUZHOU INST OF INDAL TECH

Railway energy route regulation and control method for renewable energy microgrid power supply

ActiveCN114362163AImprove negative sequenceImprove reactive powerLoad balancing in dc networkPower supply linesPower qualityMicrogrid
The invention discloses a renewable energy micro-grid power supply railway energy route regulation and control method, which comprises an energy management layer for switching a current operation mode of a system based on real-time operation data and calculating to obtain a current and / or power instruction compensated by each route subsystem; the regional decision-making layer is used for distributing reference power and / or reference current of each routing subsystem; and the equipment control layer is used for coordinated control of each routing subsystem and the direct-current micro-grid. According to the invention, the regenerative braking energy of the train can be effectively recycled; renewable energy sources are accessed to a traction power supply system, and the energy consumption of a three-phase power grid is reduced; when the traction network has a short-time fault, the power supply capability within a certain period of time can be ensured; the fault-tolerant capability is realized; the electric energy quality problem of a traction power supply system can be effectively improved; and the tolerance requirement on internal power electronic devices in a high-voltage and high-capacity environment can be relieved.
Owner:SOUTHWEST JIAOTONG UNIV

Self-adaptive feedforward active noise reduction method based on neural network, computer readable storage medium and electronic equipment

The invention relates to a self-adaptive feedforward active noise reduction method based on a neural network, a computer readable storage medium and electronic equipment. The method is used for improving conditions of harmonic waves and intermodulation distortion generated by a link, and comprises the following steps: constructing a first neural network model, and based on an adaptive feedforwardactive noise reduction architecture, taking the constructed first neural network model as a feedforward filter in the architecture; and / or constructing a second neural network model, based on the adaptive feedforward active noise reduction architecture, using the second neural network model as a secondary channel estimate S '(z) in the architecture.
Owner:COSONIC INTELLIGENT TECH CO LTD

Permanent magnet wind power generator set

The invention relates to wind power generation devices, in particular to a permanent magnet wind power generator set, aiming at solving the problems that the improvement of output power of the existing permanent magnet wind power generator set is limited, and the like. The permanent magnet wind power generator set comprises a permanent magnet wind power generator and a frequency conversion device connected with the permanent magnet wind power generator, wherein the permanent magnet wind power generator is provided with 3n three-phase or single-phase armature windings which are electrically isolated from one another, and n is a natural number which is greater or equal to 2; the frequency conversion device comprises 3n power modules, each power module consists of a three-phase or single-phase pulse-width modulation (PWM) rectifying circuit, a direct current (DC) chopping circuit and a single-phase full-bridge inverter circuit; each three-phase or single-phase armature winding is connected with the input end of the rectifying circuit of the corresponding power module; the 3n power modules are divided into three groups, and the output ends of the single-phase full-bridge inverter circuits of the n power modules in each group are connected in series; three-phase alternating current (AC) output of the frequency conversion device is formed by the three groups of power modules which are in series connection. The output power of the permanent magnet wind power generator set is greatly improved, and reaches up to 2.5WM or more.
Owner:李卓洋

Magnetically-controlled static var compensator

The invention discloses a magnetically-controlled static var compensator, which mainly solves the defects that in the prior art, the existing reactive compensation is stepped and low in accuracy, and cannot provide inductive reactive power or capacitive reactive power synchronously; the switching operation is frequent; the higher requirements of the electrical power system and users cannot be met. The magnetically-controlled static var compensator comprises a digital signal processor, a power supply, a capacitor bank or a filter bank, a keyboard, a liquid crystal displayer, a programmable logic controller, a reactive compensation unit, CSR (Controllable Shunt Reactors), and an AD (Analog-to-Digital) sampling circuit, wherein the output ends of the power supply, the capacitor bank or the filter bank and the keyboard are all connected with the digital signal processor; the input ends of the liquid crystal displayer, the programmable logic controller and the reactive compensator are all connected with the digital signal processor; the controllable shunt reactors are connected with the reactive compensation unit and the programmable logic controller; the input end of the AD sampling circuit is connected with the controllable shunt reactors, while the output end is connected with the digital signal processor. By virtue of the scheme, the magnetically-controlled static var compensator can reach the target of high cost performance and meet the actual demand, and is of high practical value and promotion value.
Owner:成都星宇融科电力电子股份有限公司

Dual-mode dielectric filter and zero point adjustment method thereof

The invention provides a dual-mode dielectric filter and a zero point adjustment method thereof. The dual-mode dielectric filter comprises a first resonant cavity and a second resonant cavity, and further comprises a plurality of dual-mode dielectric blocks located between the first resonant cavity and the second resonant cavity, and each dual-mode dielectric block is sleeved with a metal cavity, a first coupling structure is arranged between the dual-mode dielectric block adjacent to the first resonant cavity and the first resonant cavity, a second coupling structure is arranged between the dual-mode dielectric block adjacent to the second resonant cavity and the second resonant cavity, a third coupling structure is arranged between every two adjacent dual-mode dielectric blocks, and the third coupling structures are spacers, the metal cavity and the adjacent spacer jointly form a resonant cavity, the spacer is provided with a coupling window, the coupling window comprises at least one first strip-shaped hole, the center line of the first strip-shaped hole in the length direction is parallel to a first central axis of the spacer, and the projection of the first strip-shaped hole on the first central axis is far away from the center of the spacer. Harmonic waves can be improved.
Owner:WUHAN FINGU ELECTRONICS TECH

Space vector modulation model voltage prediction method

The invention provides a space vector modulation model voltage prediction method, and belongs to the technical field of power electronics. The method comprises the steps of firstly, establishing a discrete mathematical model of a converter, and obtaining a current value at the next moment through the mathematical model and state variables such as a grid-side voltage value, a current alternating-current-side current value and an output vector voltage value; secondly, enabling the obtained current value at the next moment to be equal to a reference value, obtaining a voltage value which should be output at the current moment, and then conducting equivalent transformation on a traditional model current prediction cost function to obtain a cost function based on the output vector voltage; andfinally, combining a simplified space vector modulation algorithm to obtain that the cost function of model voltage prediction control is minimum when three duty ratios are minimum so as to achieve anexpected control target. The algorithm is simple to implement, does not need to perform cyclic optimization like the traditional model current prediction, has good flexibility and expansibility, andis suitable for engineering application.
Owner:SOUTHWEST JIAOTONG UNIV

Power factor correction circuit and control method thereof, medium, compressor and air conditioner

PendingCN113972831AImprove input current harmonics and power factorRaise bus voltageAC motor controlEfficient power electronics conversionCapacitancePower factor correction circuits
The invention discloses a totem pole power factor correction circuit and a control method thereof, a medium, a compressor and an air conditioner. The totem pole power factor correction circuit comprises a rectifier module, an inductor module, a capacitor module, a switch module and a control module, and the control module is used for controlling the rectifier module and the switch module to work in a high-frequency switch mode or a multi-pulse mode according to working parameters of the load. When working in a high-frequency switching mode, the input current waveform can be controlled to change along with the input voltage, so that the input current harmonic wave and the power factor are improved, the bus voltage is raised, and boost output is realized; and when working in a multi-pulse mode, the totem-pole power factor correction circuit can realize voltage-multiplying output with lower loss, and the totem-pole power factor correction circuit can realize boosting and voltage-multiplying functions, so that the totem-pole power factor correction circuit adapts to voltage requirements of different working parameters of a load, and keeps the advantage of high efficiency of the power factor correction circuit. The correction circuit is widely applied to the technical field of electronic power.
Owner:GD MIDEA AIR-CONDITIONING EQUIP CO LTD +1

Harmonic and stray electromagnetic radiation restraining material and preparation method thereof

The invention discloses a harmonic and stray electromagnetic radiation restraining material and a preparation method thereof. The harmonic and stray electromagnetic radiation restraining material is prepared from the following components in parts by weight: a radar absorbent, liquid rubber, a sulfurizing agent, a mildew preventive, an anti-aging agent and a diluent. The preparation method comprises the following steps: heating the liquid rubber, the sulfurizing agent, the mildew preventive, the anti-aging agent and the diluent, and uniformly mixing according to a formula amount; adding the radar absorbent; fully mixing; grinding; performing curtain coating and drying to obtain a thin green body; preforming vulcanization to obtain the restraining material disclosed by the invention. The restraining material has the characteristics of high harmonic and stray electromagnetic radiation restraining capability and superior mechanical property, and the problem of interference of harmonic andstray electromagnetic radiation generated by large-power frequency equipment on peripheral precision electronic equipment can be solved effectively.
Owner:湖北航聚科技有限公司

APFC method of boost with no DC bias and no electrolytic capacitor

The invention discloses an APFC method of boost with no DC bias and no electrolytic capacitor. Two sets of high-frequency and self-excitation push-pull oscillation circuits are connected to a Boost circuit, so that the APFC process includes two low-frequency switch tubes controlled by a single-chip microcomputer MCU respectively regulate and control the high induction of the two sets of high-frequency and self-excitation push-pull oscillation circuits. The method improves the reliability when no electrolytic capacitor is used, and realizes control of accurate pulse duty ratio one by one. Real bottom switch QR is realized, heating is lowered, and output current with low ripples is realized. High power factor and power efficiency are realized, cost is low, and DC bias and electrolytic capacitor pollution problems can be prevented.
Owner:NANNING CHANGMENG ELECTRONICS TECH +2

Hybrid transformer with transformation and improved harmonics functions, unbalanced current, and a power supply system thereof

The present invention relates to a hybrid transformer. In a transformer comprising a primary core and a secondary coil, the hybrid transformer includes a core with a 1st leg, a 2nd leg, and a 3rd leg; and a secondary coil with a 1st winding, a 2nd winding and a 3rd winding, which are wound zigzag on said 1st leg, said 2nd leg, and said 3rd leg. Two types of windings selected from a group consisting of said 1st winding, said 2nd winding and said 3rd winding are wound alternatively on said 1st leg, said 2nd leg, and said 3rd leg, respectively. However, the two types of windings wound on said 1st leg, said 2nd leg, and said 3rd leg, respectively, are wound in an overlapping manner around said core in the winding order.
Owner:ENERTEC
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