RU1308138C - Series inverter - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to a DG1YA device for converting direct current into pulsed DC and can be used as power sources for arc and plasma arc cutting. The aim is to increase the output of power and reliability. The device contains an even number of cells, each of which consists of Ti-iDticiopa 4, capacitors 5 i windings 9, 20 traisformsgrsvs (t) 12. I. Additional heating circuits 21.22 1 12 , 14 are connected in series according to t-; .1og; .l. to the input terminals through the reverse ones. In Cntin 6, 7. The connection point of the windings is 21.22 under cP. It is connected to the terminals, ps c / nerisum B, E and l capacitors 15, 1 & winding - 23, 24 through drosse. pi 10.11 and p, diode diodes 17, 18 are connected to the load. The reasons for NZPR, 9) Kenya on thyristors 4 are always constant for the same reason as in the short circuit mode, TSK ii s. Idling mode. In the load), the last recharge current and the condensation Tdt pe cy eparation are supplied. 2 ill. , 1 UTT. R fi-. l f. t I b - i 1.0 I vi - V b / ° -t Y4 S. Sy s f & s and kf

Description

The invention relates to devices for converting direct current to pulsed and can be used as power sources for arc welding and plasma-arc cutting.

The aim of the invention is to increase the output power in the load circuit and reliability.

In Fig., T is a circuit diagram of a series inverter; NC FIG. 2 - time diagrams of currents I m voltage U on circuit elements; a - voltage at the cell tiritor in idle mode; b - current passing through the primary winding of the transformer in idle mode; c - voltage at the primary winding of the transformer in idle mode; g - voltage on the thyristor of the cell in the short-circuit mode; e - voltage on the primary winding of the transformer in the short circuit mode; e - three at the output terminals of the inverter in the short-circuit mode (kani; g - voltage at the additional capacitor in idle mode,

The inverter contains an even number of cells 1 and 2, connected to each other in series-parallel, the first of which is connected to the positive terminal of the power supply 3 and each of which includes parallel connected thyristor 4 and capacitor 5, check valves G and 7 according to the number of cells, two in series according to the connected recovery diodes 8 and 9, the diode 8 re (cope cathode is connected to the positive terminal of source 3 ni / iTa- ni.

In addition, the inverter contains reactors 10 and 11. transformer T2, control unit 13. transformer 14, additional capacitors T5 and .16, isolation diodes 17 and 18. At the same time, the inductors tO m AND are made windings, and the transformers 12 and 14 three-winding. The first1 - current windings 19 and 20 of the corresponding transformers 12 and 14 are connected in series with the thyristor 4 of each cell 1 and 2, respectively, the additional windings 21 and 22 of each transformer 1-2 and 14, respectively, are connected in series according to the corresponding reverse) M1 / with valves 6 and 7, moreover, the anode of valve 6 is connected to the negative terminal of the power supply 3 and the common point of the windings 21 and 22 of the transformers 12 and 14 is connected to the common point of the recovery diodes 8 and 9, in parallel with which additional capacitors 15 and 16 are included, and secondary windings 23 and 24, respectively, of transformers 12 and 14 through corresponding

5

0

6

0

5

0

0

5

The inductors 10 and 11 and the diodes 17 and 18 are connected to the output terminals 25 and 26 of the inverter.

The operation of the proposed inverter is as follows. Operating mode - idling (load resistance is equal to infinity),

The magnitude of the voltage across the capacitor 5 (cell 1) is equal to

and,

3

d, ce Us Value of voltage of source 3;

Wi9 - the number of turns of the primary winding of the Transformer 12;

NZV number of turns of transformer recovery winding 12.

The same voltage is applied to the thyristor 4 of the first cell. At time ti (Fig. 2a), a control pulse is supplied to the thyristor 4 from the control unit 13, the voltage on the thyristor drops to zero (fit, 2a), and the voltage Ui9 is applied to the primary winding 19 of the transformer-12 (cell 1) (Fig. .2c), at time instant 12, the core of the transformer 12 (Fig. 1) is saturated and the oscillatory discharge of the capacitor 5 (cell 1) begins through 4 and the residual inductance of the primary winding 19, the current is shown in Fig. 26.

At time ta, the voltage across inductance 1 5V of the resistive current winding 19 becomes equal. and the current through it (FIG. 26) reaches a maximum. The voltage across the capacitor .16 (Fig. 2g) up to time t3 is equal to the voltage of the source 3 with the polarity shown in Fig. 1, The voltage across the windings 19 and 21 changes sign, the valve 7 opens and the winding 21 is loaded onto the source 3 and capacitor 16; The voltages of the source 3 and the capacitor 16 are equal in magnitude to the opposite directions. Since the windings 19 and 21 are magnetically coupled, the transition of the current from the winding 19 to the winding 21 begins, while the current of the winding 19 decreases to zero at time t4. the capacitor 16 is discharged to zero (Fig. 2g), the regenerative current is closed to a circuit; winding 21. ventil 7, source 3, diode 9, The current drops linearly, the electromagnetic power returns to source 3, the voltage on the primary winding 19 (FIG. 2), the capacitor 5 remains constant, a small voltage is applied to the thyristor 4 reverse voltage throughout the entire energy recovery interval. At time ti (Fig. 2a), the recovery is stopped, the voltage across the winding 19 (Fig. 1) becomes equal to zero. The reverse voltage on the thyristor 4 rises abruptly to the voltage on the capacitor 5 (Fig. 2a) and remains constant in magnitude until the thyristor 4 of the second cell is turned on: the form of its change is shown in Fig. 2. 2a after time te.

The order of operation of cell 2 in idle mode does not differ from the order of operation of the first cell by virtue of this 4-th scheme.

Let us consider the order of operation of inverters in the short-circuit mode. At time ti, thyristor 4 (cell 1) is turned on, the voltage of capacitor 5 is applied to the primary winding 19 of transformer 12, the form of voltage Dig is shown in FIG. 2d

The current of the transverse winding 19 repeats the reduced current shape (Fig. 2e} of the secondary winding 23. The current of the secondary winding flows through the inductor 10, diode 17. The oscillatory re-output voltage of the capacitor 5 is determined by the reduced inductance of the inter-circuit 10. At time t3 ( Fig. 2d), the voltages on the windings 19, 21, 23 of the transformer 12 change sign and reach an unambiguous multiple level corresponding to the opening of the valve 7 when the voltage on the winding 21 reaches a different voltage value of the power supply 3.

The primary current 19 of the transformer 12 is stopped. The energy stored in the inductor 10. is recovered to source 3 in a chain; winding 21, valve 7, source 3, diode 9. Currents circulate only in the chains of windings 23 and 21, fall along

Formula of the invention

A serial inverter containing an even number of cells connected in pairs in series and connected to the corresponding input terminals, each of which consists of a thyristor connected in series and the primary winding of the corresponding electromagnetic element, shunted capacitors. and additional windings of the indicated electromagnetic elements of each pair of cells are connected in series according to and through an appropriate pair of check valves connected to the input terminals connected to two recovery diodes connected in series, the point

linear law up to the moment of time tS (Fig. 2d). Go to o5mot. becomes equal to zero, the reverse voltage appears on the thyristor 4, equal to the voltage on the capacitor 5 and

,, Wio equal to TT; -. Since the amount of voltage

Wo 1

on the capacitors 5 cells of the first and second should be equal to the voltage of the source 3, then the direct voltage on the thyristor 4

the second cell is equal to Uz (1

Wl9. 1L / 21

The voltages on the thyristors of the circuit are always constant in magnitude both in the short-gap mode ;; neither, nor in the idle mode, and are equal - direct, for example,

ultrasonic voltage (1 + --- negative voltage D, t1

n wio

W2t

The load (to the terminals 25 g -: - 26) receives the total recharge current and the inverter ondeisators, as well as the recuperation current.

The invention of Posol from at those output frequencies to increase the output power by 3-3.5 times with other equal conditions m.chh, regul11rog1ach1G5 output power MS.ZHKO. CONSTRUCTION CH5 READY

either by way of or by warming up the cordial transformformtorGH) ns-tJcrosHnwM current (increased - i.e., no-load current that cannot be transformed into KSfpy icy).

(56) Atorsky certificate of certificate of the USSR No. 1011016, kp. H 02 M 7 / 51b. | U80. USSR copyright certificate. class H 02 M, 1983,

the connections of which are connected C) to the connection points of the indicated additional voltage windings, as well as an additional electromagnet element and control unit, characterized in that, in order to increase the output power to the PO transformation paths, the current is redirected by the g / senna sensors to the load circuit m. EXTRAORDINARY, it is equipped with two additional capacitors and isolating, dkozmi, as an additional e. the electromagnet element using the chokes, s and the quality of the electromagnetic ephemete cells are transformers, the secondary winding of each of which is connected to the output outputs of the corresponding choke and a diode,