116results about How to "High power factor" patented technology

A power conversion system includes a first converter having a DC side and an AC side and a second converter having a DC side and an AC side. The DC sides of the converters are connected in series with a battery connected in parallel across the DC side of the first converter. The AC sides of the converters are connected in parallel across an AC voltage grid. A DC generating power source is coupled across the DC sides of both converters. The first converter is bi-directional with the second converter being either an inverter providing DC to AC conversion or alternately a bi-directional inverter.

A method of controlling a brushless permanent-magnet motor that includes rectifying an alternating voltage to provide a rectified voltage having a ripple of at least 50%, and exciting a winding of the motor with the rectified voltage. The winding is excited in advance of zero-crossings of back EMF by an advance period and is excited for a conduction period over each electrical half-cycle of the motor. The advance period and / or the conduction period are then adjusted in response to changes in the speed of the motor and / or the RMS value of the alternating voltage so as to maintain constant average power. Additionally, a control system that implements the method, and a motor system that incorporates the control system.

Using resetable integrator carries out integral conformity calculation for voltage signal of output difference of voltage error amplifier, and input current signal obtained from sensor respectively. Then, using comparison operation controls work cycle of switch to make input current and input voltage in AC / DC power converter in proportion and in same phase. Comparing with traditional PFC circuit, the disclosed control mode uses fewer parts and is simpler. The disclosed device is easier to be integrated to packaging body with fewer pins as well as can obtain high power factor and low total harmonic distortion.

Provided is a power control apparatus for high frequency dielectric heating, which is not affected by magnetron types, fluctuations of characteristics, power supply voltages and the like. The power control apparatus is provided with input current detecting sections (71, 72) for detecting an input current to an inverter circuit (10), which rectifies (31) an alternating current power supply voltage (20) and converts it into high-frequency power by performing high-frequency switching. A switching frequency control signal (92) wherein input current waveform information (90) from the input current detecting section and power control information (91) are mixed, is converted into a drive signal of semiconductor switching elements (3, 4) of the inverter circuit.

The invention belongs to the technical field of energy materials and in particular relates to a trace Cu-doped Bi2S3-based thermoelectric material. In the thermoelectric material, metal simple substance Bi and Cu powder with the purity of 99.99 percent and simple substance S powder serve as raw materials, the thermoelectric material is prepared according to a chemical general formula of CuxBi2-xS3, wherein x is mole fraction of a Cu component and x is more than or equal to 0.001 and less than or equal to 0.05, and the thermoelectric material is prepared into a block material by combining a discharge plasma sintering technology and a mechanical alloying method. By the method, the trace Cu-doped Bi2S3-based block thermoelectric material can be easy and convenient to prepare, trace Cu is introduced into a Bi2S3 lattice, the carrier concentration of a sample is improved, a power factor is optimized, a Cu-S nano deposition coherent with a substrate structure is formed, and the thermal conductivity is greatly reduced; therefore, the thermoelectric performance of the Bi2S3-based block material can be greatly improved.

The present invention relates to an LED luminaire driving circuit with high power factor, comprising: a filter unit, a rectifier unit, a transformer unit, a power switch unit, a zero current detecting unit, a feedback unit, an error amplifier unit, and a power switch driving unit. Particularly, the LED luminaire driving circuit proposed by the present invention does not include any optocoupler feedback circuits, so it is able to effectively reduce the entire circuit manufacturing cost of this LED luminaire driving circuit. Moreover, this LED luminaire driving circuit can selectively work under CCM operation or DCM operation with high power factor (PF˜1), and provide stable output voltage signal and output current signal to load end. In addition, this LED luminaire driving circuit performs excellent stability and current modulation error rate (<±3%).

The invention discloses an oxygen-doped molybdenum disulfide thermoelectric material preparation method. The method comprises the following steps: a certain mass of MoS2 powder is firstly weighed and tiled on a corundum boat and is then put to a quartz tube of a horizontal tube furnace, a certain temperature rises, constant temperature is kept for a certain time in an air atmosphere, oxygen-doped molybdenum disulfide powder is obtained, and finally, a spark plasma sintering (SPS) technology is used for sintering a compact bulk thermoelectric material. The polycrystalline oxygen-doped molybdenum disulfide thermoelectric material obtained by the preparation method of the invention is obvious in preferred orientation, conductance and Seebeck coefficients are high, and the thermoelectric performance is good; besides, the oxygen-doped molybdenum disulfide can be applied to fields such as electrochemistry, photoelectrocatalysis and electronic devices.

The invention discloses a preparation method of thermoelectric material Ag compound (Ca(1-X)LaX)3Co4O9, and relates to the preparation method of Ag compound oxide thermoelectric material. The invention resolves the problems that the distribution of Ag phases in an Ag compound Ca-Co-O-based oxide is not even, the size of Ag phase particles is large, thereby leading that current carrier transporting loop is formed between Ca-Co-O-based oxide crystal grains, and leading Seebeck coefficient of the Ag compound Ca-Co-O-based oxide to be reduced evidently, and the existence of lanthanon results in decreasing the electrical conductivity of the Ca-Co-O-based oxide. The preparation methods comprises that firstly, calcium nitrate, cobalt nitrate and lanthanum nitrate are dissolved in distilled water; secondly, citric acid is add; thirdly, silver nitrate is added; fourthly, organic monomers and network agent are added; fifthly, initiating agent is added; sixthly, microwave dry is performed; seventhly, calcination is operated; eighthly, the spark plasma sintering is performed. The distribution of Ag phases in Ag compound (Ca(1-X)LaX)3Co 4O9 prepared by the methods of the invention is even, the size of the Ag phase particles is smaller than 500 nm, and the current carrier transporting loop is not formed. The Seebeck coefficient of the Ag compound (Ca(1-X)LaX)3Co4O9improves 1.7 percent to 4.9 percent than that of the Ca3Co4O9, the electrical conductivity improves 13.3 percent to 38.9 percent, and the power factor improves 21.6 percent to 35.1 percent.

The invention provides a control circuit which is used in a power factor corrector. The power factor corrector transforms an AC input voltage after being rectified to a rectifying voltage; the control circuit outputs a switching signal so as to control a power switch; the control circuit comprises a voltage division filtration circuit which produces an input current signal and an effective value voltage signal after voltage division and filtration for the rectifying voltage according to an effective voltage signal, the wave shape of the input current signal is the same as the wave shape of the rectifying voltage, and a DC level is improved. The control circuit also comprises a gain modulation circuit which produces a control signal according to the input circuit signal, the effective value voltage signal and an error signal, the error signal is produced by one output terminal of the power factor corrector, and the control circuit further comprises a switching circuit which is coupled with the gain modulation circuit and outputs the switching signals according to the control signal and a sawtooth wave signal, wherein, the input current signal with DC level can improve the power factor and lower the total harmonic distortion.

The invention relates to a hole compensation type skutterrudite thermoelectric material and a preparation method of the hole compensation type skutterudite thermoelectric material. The hole compensation type skutterudite thermoelectric material is shown in the following description: RyA(4-x)BxSb12 / z NC, wherein x is equal to or greater than 0.01 and equal to or less than 0.5, y is equal to or greater than 0.01 and equal to or less than 1 and z is equal to or greater than 0% and equal to or less than 10%; R is selected from at least one of the following group of elements: Ca, Ba, La, Ce, Pr, Nd and Yb; A is selected from at least one of the following group of elements: Fe, Co and Ni; B is selected from at least one of the following group of transition metal elements: Ti, V, Cr, Mn, Fe, Nb, Mo, Tc and Ru, and electron number of the element B is less than that of the element A; and NC is in phase II, wherein z is mole% in the phase II of the thermoelectric material. The invention also provides the preparation method of the hole compensation type skutterrudite thermoelectric material.

The invention relates to a K hole doped polycrystalline SnSe and a preparation method therefor, and belongs to the technical field of energy materials. The method comprises the steps: firstly taking high-purity Sn, K and Sn elementary substances as raw materials, and enabling the raw materials to be prepared into compound powder through an improved mechanical alloying method; secondly employing a spark plasma sintering method, and adjusting the mechanical alloying method and the technological parameters of the spark plasma sintering, thereby achieving the effective doping of K elements, and obtaining K hole doped polycrystalline SnSe through preparation, wherein the atomic ratio of Sn: K: Se is equal to (1-x): x: 1, and x is greater than zero but not greater than 0.1. The K hole doped polycrystalline SnSe is low in heat conductivity, and is high in carrier concentration, power factor and ZT value, wherein the heat conductivity can decrease to 0.20W / mK at the temperature of 773K, and the maximum power factor and the maximum thermoelectricity optimum value ZT respectively reach 350 [mu]W / mK2 and 1.08. The method optimizes the thermoelectric performances, is simple and convenient in technology, is low in cost, and is high in practicality.

The invention discloses a method for preparing a high-thermoelectric-property metal oxide. The method comprises the following three steps of a, synthesizing metal oxide nano particles which are doped with heteroatom; b, mechanically ball milling and mixing the nano particles; and c, sintering the metal oxide nano particles. The metal oxide nano particles doped with the heteroatom prepared by adopting a burning method are simple and rapid to synthesize in one step, and the repetition is high. By adopting the method, the power factor which is related to the electric performance can be maximally increased while the heat conductivity is reduced, so that the ZT (zone time) value, i.e. the thermoelectric property, of a thermoelectric material can be greatly increased.

The invention proposes a flexible silicon-based nanometer thin film thermoelectric device. The flexible silicon-based nanometer thin film thermoelectric device comprises a flexible glass substrate, wherein silicon-based nanometer thin film thermoelectric arms, graphene electrodes and a graphene coating layer are arranged on the flexible glass substrate, the silicon-based nanometer thin film thermoelectric arms are deposited on the flexible glass substrate by a physical vapor deposition technology, and the silicon-based nanometer thin film thermoelectric arms are connected by the graphene electrodes. In the flexible silicon-based nanometer thin film thermoelectric device, the flexible glass substrate is adopted, a high-temperature rapid annealing process can be adopted during the preparation process of a nanometer silicon-based thin film deposited on the surface of the substrate, the generation of quantum dots and superlattices are facilitated, and the thermoelectric performance of the silicon-based nanometer thin film is substantially improved.

The invention discloses a high-efficiency energy-saving charger, which is formed by sequentially connecting an input electromagnetic interference (EMI) module, a rectification filtering module 1, an active power factor corrector (APFC), a direct current (DC) / DC regulation module, a rectification filtering module 2 and an output EMI module. An over-voltage and over-current detector is connected between the rectification filtering module 1 and the APFC. A voltage and current power factor detector is connected between the rectification filtering module 2 and the output EMI module. A protection control circuit is also connected to the DC / DC regulation module, and is also connected with the over-voltage and over-current detector and the voltage and current power factor detector respectively. The high-efficiency energy-saving charger has the remarkably advantages of increasing a power factor of electrical equipment and reducing harmonic pollutions to a power grid.

The invention relates to a p-type skutterudite material and a preparation method thereof. The invention provides the p-type skutterudite material which has a chemical formula as represented by IyFe4-xMxSb12 / z(phi), wherein, I is one kind or more kinds of filling atoms in a skutterudite phase, the filling amount y of the filling atoms is no less than 0.01 and no more than 1, M is one kind or more kinds of dopant atoms, the dopant amount x of the dopant atoms is no less than 0 and less than 4, phi is one kind or more kinds of second phases, the molar ratio z of phi is no less than 0 and no morethan 0.5, and second phase sediment disperses in the skutterudite phase. The invention also provides the preparation method for the p-type skutterudite material.

The invention discloses a switch power supply of a power factor correction controller, comprising a boosting converter, a current detection unit, an operational unit and a switch control unit; the current detection unit is used for detecting or driving current to pass through an energy transferring device, and the energy transferring device is composed of a diode or a switch commonly; the current detection unit is used for detecting inductive current or switch current. Under the condition of no-load direct detection, the optical switch breakover time is operated by an arithmetic element according to the current detection unit, or the switch can be powered off at any time; in the switch power supply of the invention, the circuit needed to detect load-end voltage in the prior art is removed, the whole weight is reduced and the system cost is reduced; in addition, the power factor of the system can be improved by detecting the current transferring way of the energy transferring, thereby being different from the prior art.

The invention relates to a method for preparing an elemental tellurium based composite pyroelectric material and belongs to the field of pyroelectric materials. The pyroelectric material is characterized by having a chemical formula of Te1-x(Sb2Se3)x, wherein x is not smaller than 0 and not greater than 0.2. The preparation method disclosed by the invention comprises the following steps: weighingvarious raw material ingredients according to a mole fraction proportioning ratio of the chemical formula, and encapsulating Te cakes, Sb powder and Se powder into a carbon-plated quartz tube throughvacuum encapsulation; then, smelting the quartz tube in a vertical tube type furnace; then, carrying out annealing treatment; and finally, grinding an obtained cast ingot into fine powder, then, carrying out spark plasma sintering, so as to obtain dense mass which has very low thermal conductivity and relatively high pyroelectric properties, wherein the pyroelectric Q-value reaches 0.95. Accordingto the method, the pyroelectric properties of the elemental tellurium based composite pyroelectric material are improved through a smelting process, an annealing process and a spark plasma sinteringprocess. Compared with the prior art, the method has the advantages that through introducing an antimony selenide component, the cooperated optimization of carrier concentration and lattice thermal conductivity is achieved, and the process flow is simple and controllable and is low in cost.

The invention discloses a method for preparing a high thermoelectrical antimony telluride micro-nano crystal and a block material thereof. The method comprises the following steps: dissolving an antimony precursor into polyol, then mixing the obtained solution with a tellurium precursor and a complexing agent, heating the mixed solution at a temperature of 140 to 180 under stirring, cooling to a temperature of 100 to 120 DEG C, adding a reducing agent, carrying out reactions at a temperature of 120 to 180 DEG C for 6 to 48 hours so as to obtain precipitate, washing the obtained precipitate by waterless ethanol until the washing liquid is neutral, drying the washed precipitate in vacuum so as to obtain antimony telluride micro-nano crystal, cold-pressing the obtained antimony telluride crystal into a sheet, and then carrying out annealing for 2 to 24 hours at a temperature of 300 to 400 DEG C in an atmosphere of mixed gas composed of Ar and H2 with a volume ratio of 92%:8% so as to obtain an antimony telluride block material. The obtained antimony telluride micro-nano crystal and block material thereof have the characteristics of high purity and good thermoelectrical property. Moreover the preparation method has the advantages of simpleness, low cost, easiness in repeating, and suitability for massive production, and thus has a good commercialization prospect.

The present invention is orientation texture treating process of thermoelectric ceramic material in material treating technology. Ca-Co-O system and La-Ca-Co-O system are taken as the experiment objects, and through sol-gel process to synthesize precursor powder, sintering in spark plasma sintering furnace to form ceramic, and hot forging to orientate at high temperature to make ceramic material possess better plasticity and ductility, thermoelectric oxide material with density as high as 98-99 % and high orientated texture may be obtained. The said treating process makes the Ca-Co-O system possess 13 % raised conductivity and 28 % raised power factor at 700 deg.c and the La-Ca-Co-O system possess 29.3 % raised conductivity and 61.3 % raised power factor at 700 deg.c. The said treating process is simple and short in treating time and can improve the processing of thermoelectric ceramic obviously.

The invention relates to a silver telluride nanowire flexible thermoelectric film welded at a room temperature and a preparation method thereof. The preparation method comprises the following steps: (1) tellurium nanowires are dispersed in a first solvent to obtain a tellurium nanowire dispersion; (2) a tellurium nanowire film is prepared by the tellurium nanowire dispersion; (3) silver ion salt is dissolved in a second solvent, and a silver ion salt solution is prepared; and (4) the silver ion salt and the tellurium nanowire film react, the film is cleaned after the reaction, and after drying, the silver telluride nanowire flexible thermoelectric film welded at the room temperature is obtained. The prepared flexible thermoelectric film has high conductivity and power factor.

The invention discloses a method for preparing an Ag-Pb-Sb-Te-Se thermoelectric material, comprising the following steps of: 1, weighing Ag powder, Sb powder, Te powder and Se powder based on the stoichiometric ratio of Ag0.8Pb18 SbTe20-xSex, and then putting the powders in a vacuum glove box under the protection of argon and uniformly mixing, wherein x is equal to 0 to 15; 2, sintering the mixed material at a temperature from 930 to 1020 DEG C for 20 minutes under the pressure of 4Gpa; and 3, stopping heating and relieving pressure to obtain an Ag0.8Pb18 SbTe20-xSex alloy. The method of the invention can effectively settle the problems in the prior art and has the advantages of being short in cycle, simple in process, fast in material synthesis, low in cost and high in sample density, saving energy, adapting to large-scale industrial production and the like, and simultaneously, the prepared product has higher powder factor and lower thermal conductivity.

The invention provides an LED constant current PWM drive circuit and a three-primary-color LED light mixing driving circuit. The LED constant current PWM drive circuit comprises a three-end bilateral switch circuit, a PWM waveform signal generating circuit and an LED constant current drive circuit, wherein the three-end bilateral switch circuit is connected with an alternating current power source and used for converting a sine alternating current signal provided by the alternating current power source into a sine chopped wave waveform signal; the PWM waveform signal generating circuit is connected with the three-end bilateral switch circuit and used for generating a PWM waveform signal by utilizing the sine chopped wave-shaped signal; the LED constant current drive circuit is connected with the PWM waveform signal generating circuit and used for controlling the on-off state of an LED light source by utilizing the PWM waveform signal, and the constant current PWM driving of an LED is achieved. According to the LED constant current PWM drive circuit, the direct driving load of the three-end bilateral switch circuit is a resistive load rather than a capacitive load, and therefore the technical scheme can guarantee high-power factors, and the quality of the whole power grid cannot be affected.

The invention relates to a Pb / Ba double doped BiCuSeO thermoelectric material and a preparation method thereof. The method is characterized in that the material is prepared from bismuth oxide powder,copper powder, selenium powder, bismuth powder, lead powder and barium oxide powder in mass ratio of (1-x):3:3:(1-4x):3x:3x; the powders are mixed uniformly, ball milling is conducted on the powders in a mill pot under an inert atmosphere for 5-12 hours; the milled PbxBaxBi1-2xCuSeO powder is put into a mould, the mould is placed in a plasma activated sintering furnace, meanwhile the temperature is increased to 500-700 DEC G in a uniform speed and the pressure is increased to 30-100 MPa in a uniform speed, the temperature maintaining and pressure maintaining are conducted, then the temperatureis reduced to the normal temperature in a uniform speed, and the pressure is reduced to the normal pressure in a uniform speed; the sintered mould is taken out, and demoulding is conducted to obtainthe Pb / Ba double doped BiCuSeO thermoelectric material, wherein 0.01<=x<=0.08. The method has the advantages of simple process, short production cycle and high production efficiency, and the preparedproducts have the advantages of high purity, low thermal conductivity, high electrical conductivity, good electrical transmission performance, high power factor and high non-dimensional thermoelectricfigure of merit ZT.

The present invention discloses an indium sulfide doped cuprous sulfide thermoelectric material and a preparation method thereof, wherein the general formula is Cu2S-xIn2S3, and x is the mole percentof indium sulfide to cuprous sulfide. The preparation method comprises two steps such as manual grinding and discharge plasma sintering, and specifically comprises: weighing a certain mass of cuproussulfide and the corresponding molar percentage of indium sulfide, completely mixing the two materials, grinding for 30-60 min by using an agate mortar, and completing sintering, doping and material preparation in one step by using a discharge plasma sintering technology (SPS) to obtain the compact bulk thermoelectric material. According to the present invention, the preparation method is simple, rapid and efficient, and the power factor of cuprous sulfide is significantly improved so as to significantly improve the thermoelectric performance of cuprous sulfide; and by introducing indium sulfide, the phase change of cuprous sulfide at the high temperature is suppressed, such that the practical application of the material can be easily achieved.

The invention relates to a series of metal-doped tungsten disulfide thermoelectric materials and a preparation method. The metal-doped tungsten disulfide thermoelectric materials have a chemical general formula of MxWS2, wherein M is one or more than two selected from Ti, V, Nb, Zr, Ta, Hf, Yb and Re, x is a mole fraction of the M metal to WS2 and 0<x< / =1. The material preparation method comprises steps: solid powder mixing and material spark plasma sintering are carried out, metal and tungsten sulfide are firstly weighed at a certain molar ratio, mechanical grinding and mixing are carried out, the mixed powder is subjected to spark plasma sintering under proper pressure and temperature, and an MxWS2 thermoelectric material is obtained after sintering. The thermoelectric material of the invention has high conductance and Seebeck coefficients, the thermoelectric performance is good, and besides, the MxWS2 material can be applied to fields such as electrochemistry, photoelectrocatalysis and electronic devices.

The invention relates to a single-crystal tin selenide pyroelectric thin film and a preparing method thereof, and belongs to the field of pyroelectric materials. The preparing method of the single-crystal tin selenide pyroelectric thin film includes the following steps of taking a substrate, putting the substrate in cleaning liquid for ultrasonic cleaning for 20 minutes, drying the substrate for 2hours at 60-150 DEG C after cleaning, taking out the substrate to be naturally cooled, putting the processed substrate onto a spinner, dropwise adding dispersion liquid onto the surface of the substrate, conducting spinning for 10-60 seconds, taking out the substrate after spinning, drying the substrate for 5-10 minutes at 200 DEG C to obtain a buffering layer substrate, putting a tin selenide sputtering target material and the prepared buffering layer substrate into a high-vacuum multifunctional magnetron sputtering film coating instrument for vacuumizing, heating the buffering layer substrate, and introducing inert gas for sputtering for 20-60 minutes to obtain the single-crystal tin selenide pyroelectric thin film. The preparing method has the advantages that the preparing process is simple, and the prepared single-crystal tin selenide pyroelectric thin film is high in single crystallinity and power factor.

The invention discloses a full-temperature-range high-performance n-type Mg-Sb-based thermoelectric material and a preparation method thereof, and relates to an n-type thermoelectric material and a preparation method thereof. The full-temperature-range high-performance n-type Mg-Sb-based thermoelectric material aims to solve the problems that an existing n-type Mg3Sb2-based thermoelectric materialcannot simultaneously obtain high performance at room temperature and high temperature and is poor in mechanical property. The chemical general formula of thefull-temperature-range high-performance n-type Mg-Sb-based thermoelectric material is B<x>Mg<3.2-x>Sb<1.99y>Bi<y>Te<0.01>. The preparation method comprises the following steps of: 1, weighing; 2, ball milling; and 3, sintering. The preparation method is used for preparing the full-temperature-range high-performance n-type Mg-Sb-based thermoelectric material.

The invention discloses a method for preparing a SiGe thermoelectric material. According to the method, Si powder, Ge powder, B powder or P blocks are mixed according to a determined molar ratio; obtained mixtures are loaded into hard steel ball mill tanks under the protection of an Ar inert atmosphere; ball-milling and alloying are performed on the mixtures through using a planetary ball mill, sothat single-phase SiGe thermoelectric material powder is obtained; the single-phase SiGe thermoelectric material powder is subjected to discharge plasma sintering at 1150 DEG C, so that dense blockscan be obtained. The P type and N type SiGe alloy prepared by the method for preparing the SiGe thermoelectric material of the present invention have high electrical conductivity, high Seebeck coefficients and high power factors. The method for preparing the SiGe thermoelectric material of the invention has the advantages of high synthesis speed, simplicity, convenience, high efficiency and wide application prospect.

The invention relates to a ternary conjugated polymer thermoelectric material with different side chain polarities, and a preparation method and an application thereof. The side chain polarities of pyrrolopyrroledione and bithiophene in the ternary conjugated polymer based on pyrrolopyrroledione and ethoxy-substituted bithiophene are different; and the structural general formula of the ternary conjugated polymer is shown in the description.