Showing papers on "Contactor published in 2018"

Novel Voltage Sag Protection Topology of Contactors for Uninterrupted Switching Capability

Abstract: Voltage sags triggered by a thunder-strike and a short-circuit fault could result in false tripping of ac contactor, a type of highly sensitive electrical equipment applied extensively. Serious consequences, such as unintended shutdown in consecutive industrial manufacturing, would be caused subsequently. Thus, an uninterrupted switching topology for ac contactor from mains supply to backup power supply is proposed in this paper, based on the reverse external voltage turn-off characteristic of the silicon-controlled rectifier. Accordingly, the exciting current is continuous, which ensures the engagement of the contactor under voltage sag and even short interruption. Simulations and experiments are conducted simultaneously. Selected emulational and experimental results are reported to validate the correctness and feasibility of the proposed topology and its control strategy.

Contactor Modeling Technology Based on an Artificial Neural Network

Abstract: We propose a new contactor modeling method that incorporates the back propagation (BP) neural network to map the complex nonlinear electromechanical coupling relation of the contactor to build its model. First, the artificial neural network (ANN) model collects the actual operational data of the contactor, including the coil voltage, coil current and moving core displacement, and then uses the strong nonlinear fitting ability of the BP neural network to perform the model training. When the training is completed, the ANN model can output the precise displacement according to the input data of the coil voltage and the coil current. Through a simple training process, this method can complete the modeling of any electromagnetic contactor. This method avoids the need to solve the complex magnetic circuit equation of the contactor and thus provides a simple and universal method for calculating the displacement of the electromagnetic switch. The co-simulation system is used to model, train, and analyze the contactor ANN model. Finally, a relevant experiment is conducted to confirm the effectiveness of the ANN model.

molded case circuit breaker

Abstract: Provided is a circuit breaker which to improve productivity and economic efficiency by reducing the number of components and simplifying an assembly process The circuit breaker of the present invention comprises: a power connection unit connected to a power source side, and having a movable contactor being selectively in contact with a first fixed contactor fixed to one side of a body unit; a load connection unit having one end thereof electrically connected to the movable contactor, having the other end thereof connected to a load side, and including a magnetic core having a coil electrically connected to a second fixed contactor fixed to the other side of the body unit wound on an outer surface thereof; an armature disposed between the power connection unit and the load connection unit, and including a driving end unit extending to perform a trip operation when an overcurrent is generated in the coil, and a suction end unit bent and extending from an upper end of the driving end unit, and sucked to the magnetic core by magnetic force formed from the coil; a trip switching unit disposed at a front side of the armature to switch a selective contact between the first fixed contactor and the movable contactor, and including a trip driving unit for performing the trip operation by being rotated by the driving end unit; and a yoke disposed between the armature and the magnetic core to reinforce the magnetic force of the magnetic core, and including a return spring for supporting the suction end unit to be rotated at an upper end portion thereof, and providing tensile force to restore a position of the armature sucked to the magnetic core, and a support spring for elastically supporting the movable contact to be in contact with the first fixed contactor at a lower end portion thereof

A Single Tube Contactor for Testing Membrane Ozonation

Abstract: A membrane ozonation contactor was built to investigate ozonation using tubular membranes and inform computational fluid dynamics (CFD) studies. Non-porous tubular polydimethylsiloxane (PDMS) membranes of 1.0–3.2 mm inner diameter were tested at ozone gas concentrations of 110–200 g/m3 and liquid side velocities of 0.002–0.226 m/s. The dissolved ozone concentration could be adjusted to up to 14 mg O3/L and increased with decreasing membrane diameter and liquid side velocity. Experimental mass transfer coefficients and molar fluxes of ozone were 2.4 × 10−6 m/s and 1.1 × 10−5 mol/(m2 s), respectively, for the smallest membrane. CFD modelling could predict the final ozone concentrations but slightly overestimated mass transfer coefficients and molar fluxes of ozone. Model contaminant degradation experiments and UV light absorption measurements of ozonated water samples in both ozone (O3) and peroxone (H2O2/O3) reaction systems in pure water, river water, wastewater effluent, and solutions containing humic acid show that the contactor system can be used to generate information on the reactivity of ozone with different water matrices. Combining simple membrane contactors with CFD allows for prediction of ozonation performance under a variety of conditions, leading to improved bubble-less ozone systems for water treatment.

Semi-theoretical prediction of the wetting characteristics of aqueous ionic liquid solution on an aluminum finned-tube desiccant contactor

Abstract: This study involves exploring a new design of an internally cooled/heated desiccant contactor by using a new ionic liquid (IL) solution as the sorptive solution. In order to optimize its operative performance, a semitheoretical model based on the principle of minimum energy is developed to predict the film rupture and wetting ability of the IL solution over a comprehensive range of IL mass fraction and flow rates. A first experimental validation of the fundamental equations of the theoretical model is presented and used as a reference to minimize deviations between predicted results and measured data by calibrating dedicated characteristic coefficients. The noteworthy quantitative and qualitative agreement in the whole range of IL mass fractions and flow rates is promising for contributing to the design of optimized system configurations and control strategies.

Analysis of Electrical Life Distribution Characteristics of AC Contactor Based on Performance Degradation

Abstract: Electrical life is an important performance indicator of ac contactor, and it is influenced by various factors, among which the most important one is arc erosion caused by arc current. This paper proposes a general contact erosion model based on arcing phase angle to simulate the electrical life distribution characteristics of ac contactor under random breaking operations. For the same type of ac contactor, different individuals have different electrical life due to the manufacturing dispersion, so the normal distribution is utilized to simulate the manufacturing dispersion under $3\sigma $ standard. The simulation results show that the electrical life distribution is closely related to the manufacturing dispersion degree. When the dispersion degree of manufacturing processes is relatively low, the electrical life obeys three-parameter Weibull distribution. Otherwise, the electrical life of contactors obeys normal distribution. Finally, the electrical life test is performed, and the test results are consistent with the theoretical analysis results. The abovementioned conclusion provides theoretical foundation for the reliability evaluation and experimental study of ac contactor.

Modified flow geometry for higher extraction performance with a liquid–liquid centrifugal contactor with Taylor vortices

Abstract: Extraction with multiple theoretical stages by a single contactor is possible when a liquid–liquid countercurrent centrifugal contactor with Taylor vortices (TVs) is used. A series of TVs inside th...

Operation coil drive device of electromagnetic contactor

Abstract: Operation coil drive device of electromagnetic contactor includes current detector and drive controller. The detector, when switching control is performed on operation coils of the contactor, detects coil current flowing through the coils. The controller controls an on/off time ratio of a semiconductor switching element wherein the on/off time ratio during close circuit control becomes larger than the on/off time ratio during holding control. Power supply voltage is switchingly applied to the coils at the on/off time ratio. The controller includes a determination locus setter and a close circuit state determiner. The setter sets a determination locus that continuously increases along a change locus of detected coil current during close circuit control. The determiner determines a contact point close circuit state by contact of a movable contact to a fixed contact based on deviation between the determination locus by the setter and the detected coil current detected.

Investigation on Contact Resistance Behavior of Switching Contacts Using a Newly Developed Model Switch

Abstract: In order to investigate the long-term behavior of contact resistance in low-voltage contactors under the influence of electric arcs in polymer housings, a new model switch was developed. The model switch permits the modification of different factors such as contact gap, contact force, closing and/or separation speed of the contacts, and arc-chamber materials among others. Several experimental series using Ag/Ni10 contacts were carried out as a reference. The contact resistance was determined using two different measurement current sources. Contact resistance data were analyzed using Weibull functions as well as nonparametric statistics. Information regarding surface structures, their chemical composition, and formed crystalline phases of contact and ambient materials on the contact surfaces was obtained through several material analysis methods. This paper presents the main characteristics of the model switch and some experimental results about contact resistance behavior under the influence of ac-arcs in outgassing polymer surroundings.

Method of protection circuit and electric pressure cooker and protection pressure switch

Abstract: The embodiment of the invention discloses a method of a protection circuit and an electric pressure cooker and a protection pressure switch; wherein the protection circuit comprises a pressure switchconnected with a power supply, an electric hot tray connected with the pressure switch and a heating module connected with the electric hot tray and used for heating the electric hot tray; the protection circuit further comprises a switch protection module, the switch protection module is connected in parallel with the pressure switch, and used for absorbing the energy flowing through the pressureswitch when the connected state of the pressure switch is changed to the off-state. According to the method, the arcing phenomenon generated by the oversize pressure between the two contactors of thepressure switch can be avoided, and the service life of the pressure switch is prolonged.

Entrainment and holdup of gas-liquid-liquid dispersion in a downflow gas-liquid-liquid contactor

Abstract: The gas-liquid-liquid downflow three-phase contactor has the advantage by dispersing gas and lighter liquid into the contactor in a continuous denser phase without any requirement of external power for gas-liquid-liquid processes like reactions and removal of organic compound dissolved in liquid. Present study focuses on entrainment rate of gas and ligheter liquid and gas holdup in gas-liquid-liquid downflow contactor. Gas holdup and entrainment are studied using Paraffin liquid-water and Kerosene-water, in the gas-liquid-liquid downflow contactor. The gas holdup variation with fixed lighter liquid volume at different gas flow rates is enunciated based on different operating conditions. Models are developed for gas entrainment and gas holdup in terms of different dimensionless groups consisting of operating variables which can be used to interpret the gas-liquid-liquid downflow contactor.

Operation coil drive device for magnetic contactor

Abstract: An operation coil drive device includes a drive control unit to perform control to set, for a semiconductor switching element to switch on and off the source voltage applied to an operation coil of a magnetic contactor, a larger ON/OFF time ratio for a circuit-closing control and a smaller ON/OFF time ratio for a holding control, wherein the drive control unit includes: a circuit-closing-control inductance calculation unit to calculate an inductance of the operation coil immediately after a start of the circuit-closing control; a circuit-closing-control resistance value calculation unit to calculate a direct current resistance value of the operation coil based on the calculation result; and a circuit-closing-control switching correction unit to correct the ON/OFF time ratio of the semiconductor switching element for the circuit-closing control based on the calculation result.

Rail traffic hybrid power circuit, energy storage power pack, and power supply method therefor

Abstract: The invention discloses a rail traffic hybrid circuit, an energy storage power pack and a power supply method thereof. The hybrid circuit comprises a lithium battery and a power grid branch circuit; the lithium battery is connected with a super-capacitor through a voltage boosting/reducing module; an output end of the super-capacitor is connected with a charging branch circuit and a first contactor; the first contactor and the charging branch circuit are connected with a load; and the power grid branch circuit is connected with the load through a second contactor. The power type super-capacitor and the energy type lithium battery are combined, the lithium battery is combined to the super-capacitor through a DC/DC current transformer, energy is transmitted between the lithium battery and the super-capacitor through voltage boosting and reduction by the DC/DC current transformer, characteristics of high energy density of the lithium battery and high power density of the super-capacitor are utilized fully, thus, a locomotive can still has high-power traction force when passing through an electricity-free region, meanwhile, regenerative brake energy is absorbed and recycled when the locomotive runs, and the purposes of energy conservation and environmental protection are achieved.

System and method for detecting adhesion of contactor of brake resistor loop

Abstract: The invention provides a system and a method for detecting the adhesion of a contactor of a brake resistor loop. The detection system comprises a braking resistance control unit, a sampling unit and apower-down control unit, wherein the brake resistance control unit is used for actively discharging a circuit at the rear end of a main contactor through a semiconductor switch tube after receiving apower-down instruction and delaying fora first preset time, the sampling unit is used for sampling the rear end voltage of the main contactor after receiving the power-down instruction and delaying for a second preset time, and the power-down control unit allowing the braking resistance control unit to enter into a standby mode and uploading fault information when the rear end voltage of the maincontactor obtained by sampling is higher than a set voltage. According to the invention, an externally-expanded complex branch detection circuit and a sampling circuit are not needed to rapidly locate the fault when an adhesion fault occurs. The detection time is short, and the whole detection process cannot influence normal power down.

System and method for power distribution

Abstract: A system for aircraft power distribution (100) includes a source of energy (112) to deliver an input power; a bus contactor (122); a set of switches (130) connected between the bus contactor and a set of essential and non-essential devices (132); a current analysis component (315) to determine a power level drawn from the source of current by the set of essential and non-essential devices (132); a variation reduction component (317) to determine an energization schedule of the set of essential and non-essential devices (132) based on reducing temporal variation in the input power drawn from the source of energy (112) to the bus contactor (122); and a switch control component (319) configured to adjust the set of switches (130) according to the energization schedule. If too much power is drawn, the set of switches (130) will be configured such as not to exceed the maximum power rating of the source (112).

Electric vehicle charging pile

Abstract: The utility model discloses an electric vehicle charging pile, including filling electric pile pile body, charging system and control system, charging system includes that three -phase AC output socket, single phase alternating current output socket, ammeter, ac contactor, lightning protection device, anticreep sky are opened, alternating current switch and inlet wire copper bar, control system includes display screen, card reader, maintenance door detection switch, an electromagnetic lock that charges, a detection switch that charges, infrared sensor, speaker and system's main control unit, fill the electric pile pile body including maintaining door, shutter, the socket opening that charges, the door that charges, charge indicator and infrared communication port. The utility model relatesto an electric vehicle charging pile provides the alternating current ability for having the on -vehicle electric automobile who charges the machine to have corresponding communication, charging andsafety protection function, through IC -card or bank card, start and charge for electric automobile, the radiating effect is good, and a large amount of heats that produce in the charging process andaccumulate can in time dissipate.

Ball type contactor comprising operating module

Abstract: The invention discloses a ball type contactor comprising an operation module. The ball type contactor includes a revolver, an operation module, and an indication module. The revolver includes a control unit, a magnet control module, a PWM control module, a zero crossing detection module, and the like. The ball type contactor has the advantages of low cost, flexible application, long service life,convenience of use, safety and reliability, and quick response.

CO2 absorption in flat membrane microstructured contactors of different wettability using aqueous solution of NaOH

Abstract: CO2 absorption in solutions of sodium hydroxide (NaOH) was performed in three membrane/mesh microstructured contactors: a single-channel PTFE membrane contactor, a nickel mesh contactor and an 8-channel PTFE membrane contactor. A membrane/mesh was used to achieve gas/liquid mass transfer without dispersion of one phase within the other. The PTFE membrane consisted of a pure PTFE layer 20 μm thick laminated onto a polypropylene layer of 80 μm thickness. The pure PTFE layer contained pores of ~ 0.5-5 μm diameter and was hydrophobic, while the polypropylene layer consisted of rectangular openings of 0.8 mm x 0.324 mm and was hydrophilic. The nickel mesh was 25 μm thick and contained pores of 25 μm diameter and was hydrophilic. Experiments were performed with a 2M NaOH solution and an inlet feed of 20% vol CO2/N2 gas mixture. Numerical simulations matched reasonably well the experimental data. CO2 removal efficiency increased by increasing NaOH concentration, gas residence time, as well as the exchange area between gas and liquid. Higher removal of CO2 was achieved when the polypropylene was in the gas side rather than the liquid side, due to lower mass transfer resistance of the gas phase. For the same reason, CO2 removal efficiency was higher for the 8-channel PTFE contactor compared to the nickel mesh contactor. Average CO2 flux was higher for the 8-channel contactor (8x10-3 mol/min.cm2 with PP on the gas side) compared to nickel mesh contactor (3x10-3 mol/min.cm2) for the same gas and liquid residence times. The 8-channel PTFE membrane contactor removed around 72% of CO2 in 1.2 s gas residence time, demonstrating the potential for CO2 absorption using flat membrane contactors.

Electric charging control device

Abstract: An electric charging control device is obtained which detects welding abnormality of an electric contactor(s) along charging passages from an electric charging plug reaching a main battery; electric charging contactors and main electric contactors are connected in series; a first voltage monitoring circuit connected between power-supply points P 1 and N 1 , a second voltage monitoring circuit connected therebetween, and a voltage-level detection circuit connected between the midpoints P 2 and N 2 are provided for producing a first voltage detection signal DET 1 , a second voltage detection signal DET 2 , and a main voltage detection signal DET 0 , each of which is a respective determination logic signal responding to the presence or absence of a monitored voltage; and a test voltage is received from either one of the main battery and a ground-based electric charging power-source apparatus, so that the presence or absence of welding abnormality in any one of the contactors is determined.

Industrial Trials of a New-Generation Contactor for the Process of the Sulfuric-Acid Alkylation of Isobutane with Olefins

Abstract: The process of the sulfuric-acid alkylation of isoparaffins with olefins in a new-generation reaction apparatus, namely, the energy-efficient tubular contactor with diffuser–confuser design, which operates in the mode of jet agitation of raw material flows and a catalyst with the arrangement of internal cooling due to partial evaporation of isobutane, has made it possible to obtain high-octane hydrocarbon fractions with a content of 3-methylpentanes of up to 47 wt % and an octane number of up to 92. Energy efficiency has been achieved by eliminating the external cooling of the reaction mass, mechanical agitation, and additional pump-forced circulation equipment. The results of the industrial trials of the new contactor have been described.

Direct current contactor service life detection method

Abstract: The invention discloses a direct current contactor service life detection method. The detection method can monitor and determine a plurality of operating data during working of a direct current contactor, such as the voltage difference between two main contacts, the temperature of the main contacts, the number of times of on and off of the main contacts and the output voltage value of an auxiliarycontact to which detection voltage is applied in the pull-in working state and the off-state working state of the main contacts in real time. When any operation data are abnormal, a controller controls a display to carry out displaying and control an alarm to make an alarm. The timeliness and accuracy of the understanding of the service life of the direct current contactor of a user are effectively improved. Normal operation of a system is ensured.

Arc Behaviors of Three Kinds of Bridge-type Contacts when Opening a Resistive Load in Range of from 300VDC to 750VDC

Abstract: The DC contactors are widely used with the development of DC power system, which raises a claim on high voltage and long lifetime contactors. The designs on contact system and arc chamber in the contactor are necessary for arc quenching and meeting the requirement of DC high voltage break. In this paper, arc behaviors when three kinds of bridge-type contacts (traditional bridge-type contact, bridge-type contact with two parallel contact, bridge-type contact with four series contact) open a DC resistive load are studied by analyzing arc shapes and waveforms of arc voltage and current. The power voltage varies from 300V to 750V, the current varies from 30A to 100A, the material of contact is copper and the arcing gas is air. Two cuboid permanent magnet are used to provide adjustable magnetic field for accelerating the arc quenching. The arc duration, the arc lengthening time and the arc blowing time can be obtained as the power voltage increases from 300V to 750V, the current increases from 30A to 100A. The magnetic field keeps 100mT. The results are of practical value for designing the contact system of a high voltage and long lifetime DC contactor.

Street lamp transformer switch intelligent control device and control method thereof

Abstract: The invention discloses a street lamp transformer switch intelligent control device. The device comprises a storage battery, an electric control device, a relay and a contactor. The contactor comprises a contactor coil and a contactor normally open contact. The contactor normally open contact is connected to a 10KV inlet wire of a street lamp transformer in series. The street lamp transformer is connected to a plurality of street lamps which are arranged in parallel. A loop between positive and negative poles of the storage battery is provided with a switch-on and switch-off knob switch. An electric control device is connected to a latitude and longitude time control module. The invention also discloses a control method of the street lamp transformer switch intelligent control device, andthe control method comprises a manual control mode, a remote control mode, a light control mode and a time control mode. The switch-on or switch-off of the street lamps can be controlled according toactual situations at any time and any place through remote control, and the device is very flexible and convenient to use. The contactor normally open contact of the invention is connected to the 10KVinlet wire of the street lamp transformer in series, a street lamp transformer does not consume electrical energy when the street lamps are switched off, the service lives of the street lamps are prolonged, and the use and maintenance costs of an entire street lamp system are saved.