SU1530368A1 - Apparatus for d.c. arc welding - Google Patents

Abstract

The invention relates to a welding technique and is intended for arc welding as an inverter DC power source. The purpose of the invention is to increase the reliability of start-up and noise immunity of the half-bridge inverter, reducing the ripple level of the welding current. The device contains serially connected input rectifier with filter, half-bridge inverter, transformer, thyristor rectifier and choke. One of the switching capacitors of the inverter is bounded by a resistor before starting to charge the other switching capacitor until the supply voltage is complete. The inverter control circuit unambiguously turns on the inverter thyristor on the charged capacitor at the time of starting. The output current is controlled by a thyristor rectifier when comparing information from the current sensor with the installation. The device allows you to extend the range of current adjustment by stabilizing the mode of operation of the inverter at one frequency. 2 Il.

Description

The invention is related to welding equipment and is designed for arc welding in and} of the intermittent power source.

Not. 11) 10 and. The point of view is to provide a reliable inverter, a twist || (stable (st1; and a decrease in the pulses of the welding current.

Pa fi I depicts the basic, electrical diagram of the device; in fig. 2 - oscillograms, on 1 - on -: lementa.

S. Schema holds the; x) one rectifier I, input (|) and, tgr 2. half-bridge inverter 3, thyristor; th rectifier 4, output filter 5, nai ruzku b in the form of a welding arc, b.yuk 7 Iranian inverter, unit 8 control thyristor rectifier. B. Hohii-Fillr 2 hoi fi1truynyi drose-seti. 9 and ifii, 1Y capacitors 10, half-bridge investor;) torus 3 contains commute- hute first and second and second 12 capacitors.

iiepBbiii 13 and second 14 thyristors, ob1 a1 to р 15 and second, I) dio: t, limiting the first 17 and second 18 dross, 1И, trans- (j) op iaTop 19, the primary processing 20 of which is included in alternating current diagonal n (), - | of the main inverter., fuzzy winding 21 trans1 () ormagor 19 Bbnio, iiiena with midpoint, second capacitor 12 across 1h; h) van by resistor 22. Secondary winding 21 Tpaiic (f ) opMaio) a 19 and connected to a hiristor output | 1 and 1.1K) 4, assembled at 23) and 23 and 24 thyristors, at the output () 1 (ny) mit.1.1 v.hpdit third reverse diode 25 and d 1se 1b 2t). which has the first 27 and horn) 28 windings. Block 7 of the control of itHBt-jiTofjoM will be supported by generator 29 pi. Jubber (voltage, counting trigger Zn, ncpi .biii 31 and second 32 formati.ti imp,;, c () I and RS- trigger 33. Sensor 34 current feeds a signal to Tiris I control unit 8 (l n | 1 mp n-sl

oo o so

05 00

the lem, which contains the adder 155, the amplifier 36, the comparison element 37, the Gers: 38 and the second 39 I-NOT elements and the Tregs 40 and the fourth 41 pulse shapers. Inverter 3 is turned on and off by the buttons 42 "Start and 43" (l

The device works as follows.

When the mains voltage is switched on, the filter 10 and the first switching 11 capacitors are charged up to a full rectifier voltage. The second commuting condensate is 12 charges as it is charged by the resis- tor 22. At the same time, the supply voltage is applied to the blocks 7 and 8 of the ppw control) torus and the generator. Generator 29 pi. A suitable voltage was developed for the sawtooth shape with a frequency of 2) (Fig. 2, voltage I ge I. that goes to the counting input of the trigger 30 and to the inverted input: 37 comparison). However, the counting t) I1-ger 30 does not work, as the logical “About with RS-ipiiiTepa 33” arrives at ei о S-input. When you click on the button 42 “11us, the trigger of the trigger 33 but is“) “(fig 2 , for example, UsjI. xpora starts counting trip er 30 (fig. 2, I aoi.). The first 31 and second 32 formulate / n. pulses, working but asymptomatic ffopg pulses etno1 about trigger 3 (1, impulses are sent to the regulator; not (krod | | and histors 13 and 14 half-bridge iiHiu-yiTc id. and the first impulse when starting iHvi.ia comes only on the first tiris1) p 13. this is determined by single opacity IR of the counting trigger 30. Inverted with S) .1 and; | - is oscillation of the first process and alternating current across the winding of the transformer (Fig. 2, Ijo) - Included when the thyristor 13 is turned on, the nepEioi 13 is not fully charged The first switch i) H1II capacitor 11 provides it with the necessary recovery time when the first diode is working 15 | FIG. 2, L), and, ultimately, it also eliminates the reliable starting of the inverter in any mode of the Nai-K from X.X to K.L. as well as to the modes of the continuous current of the inverter, when u)) f where idy is the frequency of the pulses of the control of thyristors, and i) o is the frequency of its own oscillation of the circuit.

The alternating current from secondary firing 21 is supplied to the thyristor cell, 1, 4. where it is rectified, and then smoothed out by the output filter 5, after which it is passed to the load 6.

The thyristor control unit 8 of the r -motor operates in the following way (taking the feedback to the load current but stitching 34 of the pa current from the dapchik (dummy Zo, where, adding up the voltage

neither by the working current Up (), PES), goes to the non-inverted in ... h1 g of the comparison element 37 through the amplifier 36, at the same substitution point 11 of the control

the duty current of the arc, (lmma of these voltages () is compared with the sawtooth of the master oscillator) a 29, into rezu. First, at the output of the comparison element 37, they are given the potential of them with a change in the duty cycle, which come in the first one, the common inputs of the first 38 and the second 39 elements And E. The second inputs of which are connected according to the outputs) three1 - hera 30, which prevents the synchronization of thyristor operation. with thyristors i.chve) mountain. (. Outputs of the first 38 and second P) 39:) L1. MENT () IN AND- NOT 1 | RYMNY1CH1YI) 1C PMnul; with a change to) 1i.seys porosity (ufig. 2 L 38. I h) go to the third 40 and fourth

0 41 f | (;; HM; HM;: V ibcob. Data of the rotator im) i) i; so with VK 1K.) 1 in the back I pponvv (, to the elements 1 I, and H..inx- ibcb is served on the dead iun iie) expo rp (. Riiei o 23 and four (24 gyris oron and hr m111e) :.

 Gakpm oGfia.iOM. any disturbance to the current Hai lzki implies that the changes are ei yn) ,; i delay with /, switching on the thyristors of the rectifier. 1 4, moreover, i p os m current increased, and with a decrease also

0 is replaced. -) - ;; i 1Н): -; will support / kiva 1 geek 1 ;; 1 1packs with |; - fucked T (J4HocibKj.

Output fi. And ..T) 5, assembled on the reverse diode 25 and the choke 26, works I.T / - way. Postoii ay ny.pyruyu iHHi i GOK load, 11 | .N1khod across the windings 27

5 n 2ft dross-e, m 2G, iyyyyy in each; 1 | 0 {; of them, the EL (which is for 1K) The investigators of the inclusion of the windings of the circuit voltage of the path of the load current. S.tedhchch note that it becomes possible in the case, KOI and both jigs are located on the same magnet | wire without gap. The diode 25 is turned on at the next shutdown of the third 23 and fourth) 24 ti-pHc (j) oB, the circuit is yc through the load caused by the emf of self-induction throttles 26.

 Thus, switching on during the start-up, the thyristor (.) Pa 13, and its operation on the fully charged capacitor 11 at 1P st | | resistor of condenser 12, eliminates the thyristor for

Q it recovers; 1ш1 with its nerve i: uui () a-tion (({1ИГ. 2, L j3), and this, in the final iiroi e, also ensures a reliable launch of the investor) in any mode of its operation. and load resistances.

Hard links synchronization of a unit up5) avlepi thyristors of the rectifier with 6, iok control of the thyristors of the inverter nosv). 1 n) g psk. Soak d) adicial distribution,: ngge; 1b. 1st in this system, y1 grow

process (control delay of control pulses and, thereby, increase the noise immunity of control, as well as eliminate the effect of distortion of the shape of the output current curve of the transformer 19 on the asymmetry of the control pulses of the rectifier.

A small value of the ripple coefficient of the load currents (Fie more than 6.3 Vo) over the entire range of regimentation, as well as a fixed part of the investment, t, which makes it possible to reduce the level and source of the welding arc.

Claims (1)

Invention Formula Device For arc welding on a COLORED current, (-power rectifier input, RADOnG) filter, path-type inverter with neri and igor 1utiruyu1imi capacitors, t) axfs1pma10r, primary obtomkk KOTopoio ik.1yuchena diagon. about | -o I have 1 half bridges (th inverter, and vmrychpa obmogka performed with the middle point and connection | 1me:; and with a thyristor rectifier five 0 Kchtem with reverse ll (JDom, geniragor of sawtooth panr gepin. f (rmi,) ovaale, 1and 11 lsov, successively I elpo connected current sensor, adder, amplify, 11, element of comparison, ot.chichak} SCHS1 p. It is equipped with a counting trigger, H8-trigger, rum. R and) 1 (. c leaMiu / i Li co) to the buttons “with a reliable start-up of the inverter and reduced pulsations of the welding current. Start and “UN with a zero wire, the first and the first 1m elements are NOT-NOT, drsn selek and resisyur, 1;)) ezietor set pair, | 1, H11 V Ch1r m commi-pc) - our V cond1 nsa Tji) li 1lums ; v; In () about invest the first inputs of the first and second elements and the LV are connected to the output of the reference element, and the second inputs are connected respectively to the outputs of the first counting trigger, the S-input of which is connected to the output RS- the trigger, and the counting one - to B1) 1 input of the sawtooth generator 1a 1p zhepi, and e) osse,: | ь contains two windings, VC. 1ch pskhledovate.no but in the ||) chain circuit at the output of the thyristor rectifier. FI.1 Chu chu w / ch / chu g