The relevant knowledge of transducer

Report of 5 bad news of air conditioning oneself calculates come down to also have 20-30W, be equivalent to a long bright lamp.

Transducer moves below labour frequency, have section report function, it is a fact. But his premise condition is: The first, high-power and for fan / pump kind laden; The 2nd, device itself has section report function (software supports) ; This is 3 conditions that reflect section report result. Besides, be indifferent to section report, without what meaning. If do not impose premise requirement say transducer is versed in frequency moves energy-saving, exaggerate namely or be commercial hype. Knew the whole story, your meeting uses him ably to serve for you. Must notice use circumstance and use condition just apply very correctly, it is implicit otherwise, credulous and " be decieved be duped " . Power factor compensation is energy-saving: Without result power not only those who add line caustic and equipment is calorific, mainer is power factor reduce those who bring about power of have rendered great service of electrified wire netting, do not have result electric energy in great quantities to spend online way in the center, equipment use efficiency is low, wasteful and serious, after device of use frequency control, as a result of the action of capacitance of wave of transducer interior filter, decreased not to have work loss thereby, increased the power of have rendered great service of electrified wire netting. Soft start energy-saving: 1: Electric machinery is good start pair of electrified wire netting to cause severe impact, and still can ask to capacity of electrified wire netting exorbitant, the big electric current of the generation when starting and the to fender and valve harm when shaking is great, very adverse to the service life of equipment, pipeline. And use frequency conversion is energy-saving after device, the soft starting function that uses transducer will make start electric current from 0 begin, maximum also does not exceed rated electric current, the impact that eased pair of electrified wire netting and the requirement to power supply capacity, prolonged the service life of equipment and valve. The maintenance that saved facility charge. 2: From theoretic tell, transducer can be used in all mechanical device that contain electromotor, when electromotor is being started, electric current can compare rated tall 5-6 of times, not only the service life that can affect electric machinery and use up more n.

When the system is being designed, the surplus with have certain can leave on electric machinery type selecting, the speed of electric machinery is changeless, but in using a process actually, want sometimes with inferior higher perhaps rate moves, because this undertakes frequency conversion,transform dispute to often be necessary. Transducer can realize electric machinery soft start, compensation power element. Nextpage 　 4, the basic composition transducer of transducer divides normally for 4 parts: Rectification unit, Gao Rong measures capacitance, inverter and controller. Rectification unit: working frequency fixed alternating current changeover is dc. Gao Rong estimates electric capacity: The electric energy after memory is changed. Inverter: Comprise electronic switch by array of high-power switch transistor, change direct current into the square wave of different frequency, width, extent. Controller: The process that presses set works, the extent that controls output square wave and arteries and veins are wide, make overlay is the alternating current of approximate sine wave, drive AC motor. 5, of transducer give the frequency with means common transducer to give means to basically have: Position operator clavier is given, contact signal is given, imitate signal is given, pulse signal is given and communication means is given etc. These frequency give means to have actor drawback each, must need to undertake choosing to install 　 according to actual place 6, voltage of output of general frequency conversion is the control means low pressure of transducer 380 ～ 650V, output power is 0.

75 ～ 400kW, working frequency is 0 ～ 400Hz, its main circuit is used hand in, straight, make circuit. Its controlled means to experience the following 4 generation. The wide modulation of sine arteries and veins of 1U/f=C of generation 　 (SPWM) controls fashion: Its characteristic is control circuit structure simple, cost is inferior, physical characteristic hardness is better also, the flowing timing that can satisfy average transmission asks, already got applied extensively in each domains of the industry. But, means of this kind of control is when low frequency, because output voltage is inferior, torsion suffers stator resistor to press falling influence to be being shown quite, make output the biggest torsion to reduce. Additional, its physical characteristic does not have dc motive after all hard, dynamic torsion ability and static timing function still are like person meaning very much, and curve of not tall, control can follow systematic performance to change ladenly and change, torsion answers utilization rate of torsion of slow, electric machinery not tall, the because of the existence of stator resistor and effect of inverter dead band function when low speed drops, stability becomes poor to wait. Because this people excogitates vector again,control frequency control. Vector of space of the 2nd acting voltage (SVPWM) controls fashion: It is with three-phase weaveform whole generates the effect to be premise, with approaching the ideal circle of electric machinery air gap to rotate magnetic field contrail is a purpose, generate three-phase modulation weaveform, less than cuts polygon to approach round means to have pilot. Via after practice is used, be being improved somewhat again, introduce frequency compensation namely, can eliminate speed pilot error; Pass amplitude of feedback estimation linkage, remove the effect of resistor of the stator when low speed; closed circuit of output voltage, electric current, in order to increase dynamic precision and stability. But control circuit link is more, and the adjustment that did not introduce torsion, so systematic performance did not get fundamental improvement. The 3rd acting vector controls (VC) means: The practice of vector control frequency control is the Ia of stator electric current below, Ib, Ic fastens asynchronous electromotor in three-phase coordinate, through three-phase - 2 photographs commutation, equivalent becomes the alternating current Ia1Ib1 that dormant coordinate department issues two-phase, repass presses rotor magnetic field directional change coming back is changed, equivalent rotates into synchronism the excitation electric current that the Im1 of dc electric current below coordinate department, It1(Im1 is equivalent to dc motive; It1 is equivalent to becoming the) of armature electric current of direct ratio with torsion, imitate the control method of dc motive next, get the control of dc motive to measure, turn over commutation through corresponding coordinate, realize the control of pair of asynchronous electromotor. It is AC motor equivalent is dc motive character actually, be opposite respectively speed, two heft undertake magnetic field be controlled independently. Through dominating rotor linkage, decompose stator electric current next and acquire torsion and magnetic field two heft, via coordinate commutation, realize orthogonality or solution Ou control. Of vector control method put forward to have epoch-making sense. In applying actually however, as a result of rotor linkage hard accurate observation, the effect that systematic character suffers electromotor parameter is bigger, and the place in the process is controlled to rotate with vector in equivalent dc motive commutation is more complex, make the actual result that dominates the effect to obtain good analysis hard. The 4th acting direct torsion controls (DTC) means: 1985, the DePenbrock of rash Er university taught Germany to put forward direct torsion to control frequency conversion technology first. This technology solved afore-mentioned vector pilot inadequacy greatly, and the construction of system with original control idea, concise palpability, good movement condition performance got developing quickly. This technology applies successfully on drive of communication of high-power of tractive of electric power engine. Direct torsion control fastens next mathematical models that analyse AC motor in stator coordinate directly, control the linkage of electromotor and torsion. It does not need to be AC motor equivalent dc motive, consequently leave out vector change coming back changes a lot of medium complex calculation; It does not need to imitate the control of dc motive, also do not need the Ou that it is solution and simplify the mathematical model of AC motor. Matrix type hands in, make control way: Frequency conversion of VVVF frequency conversion, vector control frequency conversion, direct torsion control is to hand in, straight, one of making frequency conversion. Its are collective defect is power input factor low, harmonic electric current is big, dc road need is big store can capacitance, second birth energy cannot feedback again wire back net, cannot undertake 4 quadrant move namely. For this, matrix type is handed in, fall frequency conversion arise at the historic moment. Because matrix type is handed in, hand in frequency conversion leave out intermediate dc link, thereby leave out bulk big, price electroanalysises expensively capacitance. It can realize power factor to be L, input electric current is sine and can 4 quadrant move, power density of the system is big. Although this technology has not mature, but still attracting numerous scholastic development to consider. Not be the indirect control electric current, quantity such as linkage character actually, serve as torsion directly however controlled the capacity will come true. Specific means is: 1, control stator linkage introduces stator linkage observation implement, implementation does not have speed sensor means; 2, identify automatically (the model of electric machinery maths with ID) mathematical support, identify automatically to electric machinery parameter; 3, cipher out is worth saturation of corresponding stator impedance, mutual inductance, magnetism actually speed of linkage of the torsion with the actual cipher out such as element, inertia, stator, rotor undertakes real time is controlled; 4, implementation Band, the Band that Band control presses linkage and torsion, Band control generates PWM signal, undertake controlling to inverter switch condition. Matrix type is handed in, hand in frequency conversion to have fast torsion to answer (<2ms) , very tall speed precision (± 2% , without PG feedback) , tall torsion precision (<+3%) ; Still have taller starting torsion and tall torsion precision at the same time, it is especially when low speed (the) when including 0 rate, can output 150% ～ 200% torsion. The control principle of VVC: The control principle of VVC is the principle application vector modulation at securing inverter of voltage source PWM. This one control builds the electric machinery model that improved in, pair of load with better model of this electric machinery and turn difference undertook compensating. Because have rendered great service is mixed,do not have composition of result electric current to control system it is very important, the improvement that the point of view that commands voltage vector can show the dynamic function inside 0-12HZ limits, and existing commonly in limits of the 0-10HZ in PWM U/F drive of the standard problem. Use SFAVM or principle of 60 ° AVM to calculate the switch mode of inverter, can make of air gap torsion pulsatile very small (compare with the transducer photograph that uses synchronous PWM) . CNC Milling CNC Machining