CN101234449A

CN101234449A - Inversion submerged arc welding electric power main circuit topological structure

Info

Publication number: CN101234449A
Application number: CNA2008100573811A
Authority: CN
Inventors: 陈树君; 张宇; 卢振洋; 王进成; 刘泽伟; 张开亮
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2008-02-01
Filing date: 2008-02-01
Publication date: 2008-08-06
Anticipated expiration: 2028-02-01
Also published as: CN100574955C

Abstract

The invention relates to a topological structure of a submerged arc welding power supply main circuit and is suitable for a field of welding technology. The topological structure of the main circuit mainly comprises a three-phase rectifier A, a filter capacitor C, a DC-AC inverter B, two groups of transformers TF1 and TF2, secondary rectifiers D1 and D2 and a double clad balancing reactor; wherein a 540V DC can be obtained through rectifying a three-phase 380V AC by the three-phase rectifier A and filtering the three-phase 380V AC by the filter capacitor C; two roads of high-frequency alternating current are obtained through the inversion and decompression of a full-bridge inverter and the main transformers TF1 and TF2; the two roads of current produce magnetic fields with opposite directions after being rectified by a fast recovery diode and filtered by the double clad balancing reactor, and the magnetic fields produced are mutually inhibited until the two roads of current are equal in size, thus leading the two roads of current to keep balance; the topological form not only extends the capacity of the main circuit, avoids a parallel current sharing theoretically but also improves the stability of the power supply and reduces the production cost.

Description

A kind of inversion submerged arc welding electric power main circuit topological structure

Technical field

The present invention relates to a kind of submerged arc welding electric power main circuit topological structure, be applicable to welding technology field.

Background technology

Four-stage has been experienced in the development of submerged arc welding electric power: arc welding transformer power supply, magnetic saturation amplifying type power supply, thyristor rectified power supply, IGBT inverter.Because arc welding transformer power supply, regulex power volume are big, weight is big, carry, inconvenient operation, cost of raw material height, this type of power supply is eliminated.At present, on the market mainly based on thyristor rectified power supply.Along with the continuous development of inversion transformation technique, the IGBT inversion submerged arc welding electric power dominates the market gradually.Other forms of inversion welding source, as argon tungsten-arc welding, CO ₂The gas shiled weldering, manual welding etc., its power demand is less, generally adopts the structure of one group of inversion unit both can satisfy instructions for use.Because the submerged arc welding electric power power capacity is big, the cyclic duration factor height.If adopt single inversion unit, one group of main transformer, secondary rectification unit, be difficult to the capacity of expansion of power supply, thereby do not adopt this kind scheme substantially.N inverter parallel connection of general employing, its basic thought is used the parallel connection of small-power inversion unit exactly, realizes the high-power big electric current of submerged arc welding electric power.

At present, the mode of the two inverter parallel connections of general employing improves the capacity of submerged arc welding electric power, as shown in Figure 1.This kind bind mode is fairly simple, but two groups of inversion unit parallel connections, distinct issues are exactly how to solve dynamic current equalizing.At present a solution is, respectively to the peak point current sampling of inverter, then with given current ratio, error signal is given pi regulator, its dynamic current equalizing situation can improve.This mode control circuit is compared with general control circuit, has increased design difficulty.

Summary of the invention

The objective of the invention is to overcome the above-mentioned defective of existing control circuit, a kind of submerged arc welding electric power main circuit topological structure is provided, not only avoided the situation of not current-sharing in parallel theoretically, reduced production cost again, expanded the capacity of power supply.

To achieve these goals, the present invention has taked following technical scheme.This main circuit topological structure mainly comprises three-phase rectifier A, filter capacitor C, DC-AC inverter B, two groups of transformer TF1 and TF2, secondary rectifier D1, D2, double-contracting paralleing reactor L.Three-phase 380V alternating current obtains the direct current of 540V through three-phase rectifier A rectification, filter capacitor C filtering; DC-AC inverter B is made up of device for power switching IGBT module B1, B2, B3, B4, IGBT module B1, B4 are a brachium pontis, IGBT module B2, B4 are another brachium pontis, and charge and discharge capacitance C1 is in parallel with IGBT module B1, and charge and discharge capacitance C2 is in parallel with IGBT module B3; Connect with capacitance Cb, pulsactor Lr in the former limit 11 of main transformer TF1, the series connection back connects the emitter E (or colelctor electrode C of IGBT module B3) of IGBT module B1, the former limit 12 of main transformer TF1 is connected with the former limit 21 of main transformer TF2, and the former limit 22 of main transformer TF2 connects the emitter E (or colelctor electrode C of IGBT module B4) of IGBT module B2; The secondary 13,14 of main transformer TF1 connects the anode of fast recovery diode D5, D6 respectively, and the

former limit

16,17 of main transformer TF2 connects the anode of fast recovery diode D4, D5 respectively; 1,3 of double-contracting paralleing reactor connects the

centre cap

15,18 of main transformer TF1, TF2 respectively; 2 of double-contracting paralleing reactor is connected output O2 with 4, the negative electrode of fast recovery diode D4, D5, D6, D7 connects output O1.

The operation principle of patent of the present invention and process:

Three-phase 380V alternating current obtains the 540V direct current through three-phase commutation bridge A rectification, filter capacitor C filtering, obtains high-frequency alternating current through full-bridge inverter then.This main circuit structure only adopts one group of inverter, does not just have two groups of inverters of Fig. 1 uneven flow problem in parallel.

Main transformer TF1 former limit winding and secondary winding are respectively N ₁₁, N ₂, former and deputy limit turn ratio is

Main transformer TF2 former limit winding and secondary winding are respectively N ₂₁, N ₂, former and deputy limit turn ratio is

And N ₁₁=N ₂₁Two groups of transformer former limit series connection, main transformer TF1 and TF2 parallel connection.

Two groups of main transformer inner magnet line of force schematic diagrames all produce clockwise magnetic field as shown in Figure 4.Like this, the two groups of former and deputy limit of main transformer turn ratios are

\frac{N_{1}}{N_{2}} = K,

And N ₁=N ₁₁+ N ₂₁=2N ₁₁=2N ₂₁, then the former and deputy polygonal voltage ratio of main transformer is:

\frac{U_{1}}{U_{2}} = \frac{N 1}{N 2} = K, \frac{I_{1}}{I_{2}} = \frac{N_{2}}{N_{1}} = \frac{1}{K}

U ₁: transformer original edge voltage I ₁: the transformer primary current

U ₂: transformer secondary voltage I ₂: the transformer secondary current

The two-way electric current flows through the winding of double-contracting reactor respectively, produce direction opposite magnetic field.If the two-way size of current is unequal, the magnetic field size of generation is also unequal, and the two suppresses mutually, equates that until the two-way size of current two-way electric current is kept in balance like this.

Compared with prior art, patent of the present invention has the following advantages:

1, this topological form has not only been expanded the capacity of main circuit, has avoided parallel current-sharing from principle, has also improved the reliability of power supply, reduces production costs;

2, the former limit of transformer windings in series, the parallel connection of secondary winding is applied to the inversion submerged arc welding electric power field.

3, adopt the filtering of double-contracting paralleing reactor, the two-way electric current produces the opposite magnetic field of direction, and the two-way electric current is kept in balance.

Description of drawings

Fig. 1 is a two-way inverter block diagram in parallel;

Fig. 2 is a submerged arc welding electric power main circuit topology block diagram of the present invention;

Fig. 3 is submerged arc welding electric power main circuit topology theory figure of the present invention;

Fig. 4 is two groups of main transformer connection diagrams of the present invention;

Fig. 5 is double-contracting paralleing reactor catenation principle figure among the present invention;

The specific embodiment

Describe present embodiment in detail in conjunction with Fig. 2～Fig. 5.

As shown in Figure 3, present embodiment includes three-phase commutation bridge A, filter capacitor C, DC-AC inverter B, transformer TF1, transformer TF2, secondary rectifier D1, secondary rectifier D2, double-contracting paralleing reactor L; Wherein, the three-phase 380V alternating current direct current that obtains 540V after through three-phase rectifier A rectification, filter capacitor C filtering inputs to DC-AC inverter B; DC-AC inverter B includes device for power switching IGBT module B1, IGBT module B2, IGBT module B3, IGBT module B4, IGBT module B1, IGBT module B4 are a brachium pontis, IGBT module B2, IGBT module B3 are another brachium pontis, charge and discharge capacitance C1 is in parallel with IGBT module B1, and charge and discharge capacitance C2 is in parallel with IGBT module B3; The former limit 11 of main transformer TF1 is connected the emitter E of IGBT module B1 with capacitance Cb, pulsactor Lr series connection back, the former limit 12 of main transformer TF1 is connected with the former limit 21 of main transformer TF2, and the former limit 22 of main transformer TF2 connects the emitter E of IGBT module B2; The secondary 13 of main transformer TF1, secondary 14 connect the anode of fast recovery diode D5, fast recovery diode D6 respectively, and the former limit 16 of main transformer TF2, former limit 17 connect the anode of fast recovery diode D4, fast recovery diode D5 respectively; 1,3 ends of double-contracting paralleing reactor connect the

centre cap

15,18 of main transformer TF1, main transformer TF2 respectively; 2 of double-contracting paralleing reactor is connected output O2 with 4, the negative electrode of fast recovery diode D4, D5, D6, D7 connects output O1.

Three-phase 380V alternating current obtains the 540V direct current through three-phase commutation bridge A rectification, filter condenser C filtering.When device for power switching IGBT module B1, B4 conducting, when B2, B3 turn-off, primary current flows through former limit winding-IGBT module B4 of IGBT module B1-pulsactor Lr-capacitance Cb-main transformer TF1, TF2 from the three-phase commutation bridge positive pole, gets back to the three-phase commutation bridge negative pole at last.Fast recovery diode D6, the conducting of D4 positively biased, D7, D5 instead end partially, and the two-way electric current flows through the winding of double-contracting paralleing reactor L respectively through arc load after the rectification, gets back to the centre cap of main transformer TF1, TF2 more respectively.At this moment, the two-way electric current produces the opposite magnetic field of direction, and the two-way electric current is kept in balance.When device for power switching IGBT module B1, B4 turn-offed, the sense of current was constant in the reactor, and transformer former limit winding and secondary winding current direction are also constant, B2, the afterflow of B3 inverse parallel diode current flow.At this moment transformer secondary winding induced potential is reverse, D5, the conducting of D7 positively biased.At this moment, the electric current that flows through D5, D7 increases, and the electric current that flows through D4, D6 reduces, and when size of current equated, the total magnetic potential of transformer secondary was zero, and primary current drops to zero, and B2, B3 inverse parallel diode are led afterflow and finished.Meanwhile, charge and discharge capacitance C1 discharge, C2 charging.

When device for power switching IGBT module B2, B3 conducting, when B1, B4 turn-off, primary current flows through IGBT module B2-main transformer former limit winding TF2, TF1-capacitance Cb-pulsactor Lr-IGBT module B3 from the three-phase commutation bridge positive pole, arrives the three-phase commutation bridge negative pole at last.Fast recovery diode D7, the conducting of D5 positively biased, D6, D4 instead end partially, and the two-way electric current flows through double-contracting paralleing reactor L winding respectively through arc load after the rectification, gets back to the centre cap of main transformer TF1, TF2 more respectively.At this moment, the two-way electric current produces the opposite magnetic field of direction, and the two-way electric current is kept in balance.When device for power switching IGBT module B2, B3 turn-offed, the sense of current was constant in the reactor, and transformer former limit winding and secondary winding current direction are also constant, B1, the afterflow of B4 inverse parallel diode current flow.At this moment transformer secondary winding induced potential is reverse, D6, the conducting of D4 positively biased.At this moment, the electric current that flows through D6, D4 increases, and the electric current that flows through D7, D5 reduces, and when size of current equated, the total magnetic potential of transformer secondary was zero, and primary current drops to zero, and B1, B4 inverse parallel diode are led afterflow and finished.Meanwhile, charge and discharge capacitance C2 discharge, C1 charging.

So far one-period finishes, and carries out next cycle.

Claims

1, a kind of inversion submerged arc welding electric power main circuit topological structure is characterized in that: include three-phase commutation bridge A, filter capacitor C, DC-AC inverter B, transformer TF1, transformer TF2, secondary rectifier D1, secondary rectifier D2, double-contracting paralleing reactor L; Wherein, the three-phase 380V alternating current direct current that obtains 540V after through three-phase rectifier A rectification, filter capacitor C filtering inputs to DC-AC inverter B; DC-AC inverter B includes device for power switching IGBT module B1, IGBT module B2, IGBT module B3, IGBT module B4, IGBT module B1, IGBT module B4 are a brachium pontis, IGBT module B2, IGBT module B3 are another brachium pontis, charge and discharge capacitance C1 is in parallel with IGBT module B1, and charge and discharge capacitance C2 is in parallel with IGBT module B3; The former limit 11 of main transformer TF1 is connected the emitter E of IGBT module B1 with capacitance Cb, pulsactor Lr series connection back, the former limit 12 of main transformer TF1 is connected with the former limit 21 of main transformer TF2, and the former limit 22 of main transformer TF2 connects the emitter E of IGBT module B2; The secondary 13 of main transformer TF1, secondary 14 connect the anode of fast recovery diode D5, fast recovery diode D6 respectively, and the former limit 16 of main transformer TF2, former limit 17 connect the anode of fast recovery diode D4, fast recovery diode D5 respectively; 1,3 ends of double-contracting paralleing reactor connect the centre cap 15,18 of main transformer TF1, main transformer TF2 respectively; 2 of double-contracting paralleing reactor is connected output O2 with 4, the negative electrode of fast recovery diode D4, D5, D6, D7 connects output O1.