163results about How to "Simple control scheme" patented technology

A membrane process for the removal of sulfur species from a naphtha feed, in particular, a FCC light cat naphtha, without a substantial loss of olefin yield is disclosed. The process involves contacting a naphtha feed stream with a membrane having sufficient flux and selectivity to separate a sulfur deficient retentate fraction from a sulfur enriched permeate fraction, preferably, under pervaporation conditions. Sulfur deficient retentate fractions are useful directly into the gasoline pool. Sulfur-enriched permeate fractions are rich in sulfur containing aromatic and nonaromatic hydrocarbons and are further treated with conventional sulfur removal technologies, e.g. hydrotreating, to reduce sulfur content. The process of the invention provides high quality naphtha products having a reduced sulfur content and a high content of olefin compounds.

The invention discloses a precise clamp used for micro-miniature complex thin-walled part machining and a control method of the precise clamp. According to the core part of the mechanical structure of the precise clamp, five gas-liquid damping cylinders connected through universal joints are adopted for the upper end and five gas-liquid damping cylinders connected through universal joints are adopted for the lower end, and therefore a platform which can rise, fall and deflect can rise and fall by 0-80 mm and deflect by 0-270 degrees according to the machining and processing requirements of thin-walled parts and can be suspended in any space and keep the required posture according to requirements, and a whole workpiece can be machined on a composite machine tool through one-time clamping; in addition, by arranging a visual system, visual and accurate machining information is provided when the micro-miniature complex thin-walled parts are machined by operators; industrial personal computer centralized control is adopted for the control method of the precise clamp, the control scheme is simple and reasonable, and the precise clamp and the control method have the advantages that the automation degree is high, control is convenient and efficient under the man-machine synergistic effect, and the precise clamp and the control method are suitable for machining micro-miniature thin-walled structural pieces with various three-dimensional complex morphologies or free-form surfaces.

The foot structure of four foot waling robot with floated foot support includes calf, subsidiary ball cover plate, knuckle, instep seat, upper washer, clamp plate, balls in holder, lower washer, sole seat, approach sensor, foot pad, feeling sensor, buffering pad, outer casing and pressing spring connected together. The present invention is light, firm and floatable, and has elastic compensation capacity and environment feeling capacity.

An apparatus for generating variable DGD is particularly for use in a PMD compensator. The apparatus has first, second and third birefringent elements arranged in order between the input and output of the compensator and having first, second and third differential group delays (DGDs) in the ratio 1:2:1. The orientation of the PSPs of the signal in each element relatively to the principal axes of the element is controlled, such that a change in orientation between the first and second elements is equal and opposite to a change in orientation between the second and third elements. This arrangement provides symmetrical relative rotations of the signal PSPs and principal axes about the central birefringent element. In combination with the 1:2:1 ratio, it can be shown that compensation of any first order PMD can be achieved without the compensator introducing additional second order PMD. The required level of first order PMD compensation is selected by controlling the amount of the orientation changes.

The invention discloses a diode clamping five-level dual buck half-bridge inverter which comprises a first five-level buck circuit, a second five-level buck circuit, a direct current power input circuit and a load circuit. The inverter is controlled by adopting voltage-current dual closed loop SPWM (Sinusoidal Pulse Width Modulation), the two five-level buck circuits are controlled to work withina half cycle according to the direction of inductive current and the magnitude of output voltage, and five-level PWM (Pulse-Width Modulation) wave output is obtained respectively on two output bridgearms through different switch combination. The invention has the advantages that the advantages of straight through without bridge arms of the dual buck circuits and diode reverse recovery without switching tube are reserved; five-level output is realized, and the harmonic wave content of output voltage is reduced, thus the size of a filter can be reduced, the switching frequency of a PWM part can be reduced, the switching loss can be reduced, and the efficiency can be improved; compared with a half-bridge type inverter, the voltage stress of power devices is reduced so that a switching device of medium or low power is suitable for occasions of high voltage and high power; and only eight power diodes are needed in the circuits, compared with a five-level diode clamping inverter, the quantity of the diodes is reduced by 1/3, and a clamping circuit is simplified.

A space synchronous method of a space-borne bi-static SAR system belongs to the processing technical field of electronic signals, and relates to the spatial remote sensing and air-to-ground observable information processing technology, in particular to the spatial synchronous technology of the space-borne bi-static SAR. On one hand, the invention broadens and receives broad beams in the azimuth direction through reducing the antenna dimension of an aircraft in the azimuth direction or only driving the partial array number of the phase array antenna of a receiving platform, thereby improving the scene length of the space-borne bi-static SAR system, on the other hand, the invention broadens and transmits the beams through reducing the antenna dimension of the aircraft in the azimuth direction or only driving the partial array number of the phase array antenna of the receiving platform, thereby improving the azimuth resolution of the space-borne bi-static SAR system. After the receiving and the transmitting beams are broadened, the scene length can achieve the magnitude of at least 1 kilometer; and the magnitude of the azimuth resolution can achieve meter level. The invention only needs to reasonably control the effective array number in the phase array antenna without changing any hardware of the prior radar system. The invention has the advantages of simple control proposal, low cost and high reliability.

Disclosed are a three-level dual-booster energy-feedback PWM rectifying circuit and the control method thereof, which belongs to PWM rectifying circuit and the control method. The PWM rectifying circuit can work at the AC/DC rectifying mode and the DC/AC energy-feedback mode, and includes a input power supply (2), two booster bridge circuits (1, 3) and an output filtering circuit (4). The control block diagram includes a voltage outer loop, a phase lock and sine wave generation circuit, an equalizing ring, a current inner loop, a zero-crossing comparing unit and an output logic circuit. Compared with traditional half bridge and dual booster rectifying circuit, the circuit adds a zero level at the middle of the bridge, thereby effectively reduces the electromagnetism interference of the circuit; the two bridge circuits works in turn at the half cycle of the power network. The voltage stress of the power switch tube of the circuit is low, which is only half of the output voltage; the energy can flow bidirectionally; the bridge has no hidden trouble of direct passing through. The circuit has high working reliability and simple structure, and is suitable for the UPS and aero-space field which requires medium and large power with high reliability.

The present invention discloses polymer functionalized molecular sieve/polymer mixed matrix membranes (MMMs) with either no macrovoids or voids of less than several Angstroms at the interface of the polymer matrix and the molecular sieves by incorporating polymer functionalized molecular sieves into a continuous polymer matrix. The MMMs exhibit significantly enhanced selectivity and/or permeability over the polymer membranes made from the corresponding continuous polymer matrices for separations. The MMMs are suitable for a variety of liquid, gas, and vapor separations such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO₂/CH₄, CO₂/N₂, H₂/CH₄, O₂/N₂, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations.

A dual range oscillator provides two different ranges of oscillator frequency output based on switched current sources charging a capacitor. As several current sources are combined to charge capacitor, the interval for charging the capacitor decreases and changes the oscillator frequency output accordingly. A reference voltage supplied to a comparator checks the voltage on the capacitor to determine when to combine current sources to charge the capacitor and modify the timing interval and the corresponding oscillator frequency output. The different current sources are switched to the capacitor to provide modified charging slopes. The dual slope, dual range oscillator permits frequency switching operation in a variety of environments and applications with a simplified control and integration into a single chip.

A high voltage DC breaker apparatus configured to break a fault current occurring in a high voltage DC conductor includes a current limiting arrangement having at least one section with at least one semiconductor device of turn-off type and at least one arrester connected in parallel therewith, and a mechanical DC breaker connected in series with the current limiting arrangement and including a mechanical switch. The mechanical DC breaker is configured to enable breaking of a fault current in said DC conductor once said semiconductor devices of said arrangement have been turned off.

A single-stage AC-DC single-inductor multiple-output (SIMO) LED driver uses a single inductor (L) to drive multiple independent LED strings (34₁-34_n) with Power Factor Correction (PFC). The driver uses a diode bridge (20) to achieve initial AC to DC conversion. The output of the bridge (20) is provided to a buck converter whose output is shared with multiple LED strings by a time division multiplex circuit. Feedback is used to separately control the current supplied to each LED string by using a separate reference for each string and controlling the width of the current pulse provided to a string. Current balancing in every LED string can be achieved with the same voltage reference without the need for additional circuitry.

The invention includes reduction voltage circuit of first and third electrical level, and reduction voltage circuit of second and third electrical level. Un the two circuits, one end of the power switch tube is connected to external electrical source; and the other end is connected to three levels combined switch composed of two power diodes and one power switch connected to each other. Advantages of the invention are: small content of harmonic wave in output voltage, reduced switch frequency and wastage of switch, no need of large capacitance on DC side, applicable to condition of high voltage and large power, no straight through issue of bridge arm, and no issue of backward recovery of diode in switch tube. Moreover, the invention possesses simple structure and control scheme, and good dynamic properties of the invention.

Provided are a pixel, a display device including the same, and a driving method thereof. A pixel includes: an organic light-emitting diode including an anode and a cathode, a first transistor configured to provide a driving current flowing through the organic light emission diode, a second transistor configured to provide data to a gate of the first transistor in response to a scan signal, a capacitor configured to maintain a difference between a voltage level of the data and a threshold voltage of the first transistor, and a third transistor configured to: sense a change of the threshold voltage of the first transistor in response to a sensing signal, and transfer a reference voltage to a node coupled to the anode when the sensing signal is enabled, wherein a level of the reference voltage is lower than a threshold voltage of the organic light-emitting diode.

The invention discloses a noncontact power transmission device and a power transmission method. A rectifier and filter circuit is used for receiving high-frequency alternating current which is output by a receiving coil; a direct current voltage signal is obtained after full-bridge rectifying and filtering processing; when the condition that the direct current voltage after rectifying and filtering exceeds a preset value is detected, a current loop is formed by a switch protection circuit, an impedance matching circuit and the receiving coil, so that the energy of the receiving coil is transferred until the direct current voltage descends to a value which does not exceed the preset voltage value; the switch protection circuit is connected between an impedance matching network and the ground; when the power transmission device normally works, the switch protection switch does not work; and when the overvoltage condition is generated, the switch protection circuit carries out a switch motion to reduce the value of the direct current voltage.

A matrix converter for converting a polyphase alternating current into a desired alternating output current includes at least two stages; a plurality of controllable bidirectional switches, converts m phases of the polyphase alternating current into alternating output current with n (n<m) phases of a load; and a controllable bidirectional switch controlling each phase of the polyphase alternating current in at least one stage of the converter.

The invention discloses a suppression method for a neutral point voltage imbalance of a five-level inverter. Capacitors are connected with a load by detecting, comparing and judging voltage amplitudes on the capacitors at a direct current side and controlling switch tubes to be connected or disconnected; the capacitor with a high voltage is discharged; and charging control is carried out on the capacitor with a low voltage, so that parallel capacitors on each upper bridge arm and each lower bridge arm all can obtain a mean direct current side voltage; and the condition that neutral voltages constantly are 1/2 of the direct current side voltage is ensured. Vector synthesis of an original SVPWM is adjusted; and meanwhile, three independent circuits are adopted by a three-phase inverter. The deviation of the neutral point voltages is within +/-10V; the adjusting time is within 0.1s; THD of a current output by the inverter does not exceed 3%; the direct current side voltage of the inverter is that voltage ripples on the capacitors CS1 and CS2 do not exceed 2%; and the overall efficiency of the inverter is improved by about 1-1.5.

The invention provides a method for controlling water jet capacity of a once dry-method dedusting evaporation cooling tower in converter steelmaking. According to the converter blowing process, the outlet fume temperature of the evaporation cooling tower is measured in real time; the outlet fume temperature of the evaporation cooling tower is divided into a plurality of continuous and equant temperature ranges; and water is respectively jetted within each temperature range according to preset fixed water jet capacities through a dry-method dedusting main PLC (Programmable Logic Controller) through a water jet capacity adjusting system. The method has the beneficial effects that firstly, the control scheme is simplified, the regulation is simple, and the on-site regulation personnel are not highly required; secondly, the water jet capacity control logic in the once dry-method dedusting system in converter steelmaking is simplified, and the investment on devices such as a heavy caliber flow measuring instrument, an evaporation cooling tower inlet fume temperature tester and the like at a static deduster outlet is saved; and thirdly, the problem that a closed loop control system is not accurate in water capacity calculation at the early blowing period and at the end blowing period is avoided.

Disclosed is dual booster/dual buck combination AC-AC conversion circuit which belongs to the AC-AC frequency conversion technology. The circuit includes a power supply, two booster bridge circuits (1, 3), two buck bridge circuits (5, 7), a DC section circuit (4) in the middle and an output filtering circuit (6). The two booster bridge circuits form a dual booster PWM rectifying circuit; the second booster bridge circuit works at the positive half cycle of the input current and the first booster bridge circuit works at the negative half cycle of the input current. The two buck bridge circuits form the dual buck circuit; the first buck bridge circuit works at the positive half cycle of the input current and the second buck bridge circuit works at the negative half cycle of the input current. The dual booster PWM rectifying circuit and the dual buck circuit all adopt the current hysteresis control method which has the ability of automatic current limit and has fast dynamic response. The dual booster/dual buck combination AC-AC conversion circuit of the invention is suitable for the medium and large power field with high efficiency, such as the airplane frequency conversion power supply, UPS, new energy electricity generation which have unified surge control and active filtering.

The invention discloses a transient stability strongly-correlated power transmission section identification method for a power grid, and belongs to the technical field of power systems and automation thereof. Different regulation modes are determined based on a transient stability quantification theory for a power system, rules of changes of the transient stability limit of a section along with the power transmission power of another section in different regulation modes are calculated, and transient stability limit influence indexes between different sections are further calculated to identify transient stability strongly-correlated sections in the power grid. The method is favorable for power system scheduling and running staff to master the intrinsic running rules of the system and make a power grid scheduling and running control decision, and the safety, stability and automation level of the system are improved.

The invention discloses a control method of a DC-DC bidirectional converter. The method is applied to the DC-DC bi-directional converter. According to the charging and discharging requirements of a first power supply and the relation between the voltage of the first power supply and the voltage of a second power supply, the DC-DC converter is controlled in different time sequences. Therefore, thebidirectional conversion is realized. Meanwhile, the current of a whole-process inductor is continuous. As a result, the bidirectional dual-conversion of a high voltage capable of falling as well as rising can be realized.

The invention relates to a dual-reduction inverter, which comprises capacitor divide circuit, the first reduction circuit and the second reduction circuit, wherein the divide circuit is formed by two serially connected first and second capacitors; the first reduction circuit has the first power switch tube, the third power switch tube and the first inductance; the second reduction circuit has the second power switch tube, the fourth power switch tube and the second inductance; the load is connected between the anode of first power diode and the cathode of second power diode. The invention has the advantages that: when the input bus voltage is lower than output voltage, the inverter also can operate invert operation, with simple structure and simple control.

A device mounter head and a device mounting method using the device mounter head are provided. The device mounter head includes: a cylinder block unit including at least one cylinder in which a piston unit moving along the at least one cylinder is disposed; a pressure control unit which controls pressure inside and outside the at least one cylinder so that the piston moves along the at least one cylinder based on the controlled pressure; and a nozzle which is connected to the piston unit, and includes an inlet exposed to an atmosphere outside the cylinder block unit and a nozzle communication vent connected to the inlet and provided with the controlled pressure, wherein the inlet is configured to suck, grab and release a component using the controlled pressure.

The invention provides a voltage dynamic balance management system of a power lithium battery pack, which relates to a charging and discharging balancing circuit of a series power battery pack. The voltage dynamic balance management system comprises a microprocessor, Hall sensor modules, channel selecting modules, a switch driving circuit module and a DC/DC (Direct Current/Direct Current) transformer, wherein the microprocessor is used for gating a single battery in the battery pack by a first channel selecting module; an input end of the DC/DC transformer is connected with two ends of the battery pack; an output end of the DC/DC transformer is connected with two ends of the single battery by the switch driving circuit module and the switch driving circuit module; an input end of a first Hall sensor module is connected with a charging current input end and a discharging current output end of a charging and discharging switch; an output end of the first Hall sensor module is connected with the microprocessor; an input end of a second Hall sensor module is connected with a balancing charging current output end of the switch driving circuit module; an output end of the second Hall sensor module is connected with an input port of the microprocessor; an input end of the switch driving circuit module is connected with an output end of a second channel selecting module; and an output end of the circuit driving circuit module is connected with two ends of the single battery of the battery pack.