CN103418892B - A kind of welding supply and control method that there is energy and keep loop - Google Patents
A kind of welding supply and control method that there is energy and keep loop Download PDFInfo
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- CN103418892B CN103418892B CN201310303980.8A CN201310303980A CN103418892B CN 103418892 B CN103418892 B CN 103418892B CN 201310303980 A CN201310303980 A CN 201310303980A CN 103418892 B CN103418892 B CN 103418892B
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Abstract
Having energy keeps the welding supply in loop and control method to comprise voltage follower circuit, power switch pipe Q1 drive circuit, current switching power switch pipe Q2 drive circuit, source current feedback filtering circuit, supply voltage feedback filtering circuit, a core control circuit, is also provided with the source of welding current main circuit having energy and keep loop; Voltage follower circuit provides voltage to source of welding current main circuit, and power switch pipe Q1 and Q2 in source of welding current main circuit is subject to the control of power switch pipe Q1 drive circuit and power switch pipe Q2 drive circuit respectively; Source current feedback filtering circuit is used for the current feedback signal filtering flowing through arc load; Described supply voltage feedback filtering circuit is used for the filtering of arc load voltage feedback signal; The core control circuit energy controlled in source of welding current main circuit keeps the break-make 2 of power switch pipe Q1 and current switching power switch pipe Q2.
Description
Technical field
The invention belongs to technical field of hot working, particularly a kind of gas metal-arc welding connects equipment.
Technical background
Gas metal-arc welding connects technique and mainly adopts two kinds of droplet transfer processes, and one is short circuiting transfer technique, and another kind is pulse transition technique.Two kinds of processes generally all adopt constant speed to send welding wire to coordinate the work of direct current flat external characteristics electric source modes.In short circuiting arc welding technique, electric arc is in intermittent combustion state, and heat input is relatively little, and the volume in molten bath is also less, so especially significant in the all-position weldings such as pipeline.But conventional short circuiting arc welding has appearance of weld difference, the shortcoming that spatter is large.
Produce to suppress short circuit and splash, at present the normal method adopting Waveform Control.Fig. 1 a-Fig. 1 c is depicted as ideal current voltage waveform and the droplet transfer process of short circuiting transfer.In the t1 moment, electric arc is in fired state, and along with sending constantly into of welding wire, arc length is shorter and shorter, and be short-circuited at t2 moment molten drop and molten bath, now voltage declines rapidly, because after molten drop and molten bath short circuit, impedance is very little, so electric current starts to rise.When molten drop and molten bath are just short-circuited, contact area is less, and form a little fluid column, this fluid column is called short circuit initial stage foot bridge.Now electric arc is shorted, and all electric currents all will flow through short circuit initial stage foot bridge.If the electric current flowing through short circuit initial stage foot bridge is comparatively large, then easily causes quick-fried disconnected, thus produce splashing.So the t2 moment occurred in short circuit, should reduce welding current rapidly, avoid short circuit initial stage foot bridge quick-fried disconnected, suppressing to splash produces.Molten drop is sprawled in molten bath gradually and is come afterwards, and the diameter of fluid column increases, and the major part of molten drop is transferred among molten bath, as shown in t3 in figure.But because short circuit initial stage electric current reduces, cause electromagnetic contractile force not enough, so after molten drop is sprawled in molten bath, electric current should be increased rapidly, impel necking down to produce, prevent the appearance of solid short circuit.After necking down produces, suitably can reduce the rate of climb of electric current.Along with electric current is increasing, and the diameter of fluid column constantly reduces.To the t4 moment, welding current rises to very high, and fluid column diameter is reduced to very little, and this fluid column is called as short circuit later stage foot bridge.Now very large electric current flows through very thin fluid column, short circuit later stage foot bridge will be caused to occur quick-fried disconnected, produce and splash.When detecting that short circuit later stage foot bridge produces, again reducing electric current rapidly, as shown in t4 in figure, also can avoid the generation of splashing.After the short circuit later stage, foot bridge was pulled off under capillary effect, electric arc is set up again, and now electric current is very little, but voltage rises rapidly, as shown in t5 in figure.Need afterwards to increase electric current rapidly, ensure that electric arc has enough energy, as shown in t6 in figure.Start next shorted period afterwards.As can be seen from Fig. 1 a-Fig. 1 c, in the stage of twice short circuit foot bridge formation, if electric current is comparatively large, all easily produce splashing.
The proper timing produced at short circuit initial stage foot bridge and short circuit later stage foot bridge reduces welding current rapidly, effectively can reduce splashing theoretically, but it is larger to realize difficulty.
This is due in the major loop of the source of welding current, in order to suppress the big ups and downs of electric current, often needs series connection filter inductance.In high frequency switch power, this inductance value is about tens of microhenry, and in industrial frequency rectifying circuit, this inductance value is up to up to a hundred or hundreds of microhenry.Circuit is a kind of structure chart of normal welding electric power main circuit as shown in Figure 2, and filter inductance is connected in the output loop of direct voltage source.In welding process, when short circuit occurs, the equiva lent impedance of whole major loop is very little, is about 0.01-0.05 Europe.And the inductance value of output inductor is generally more than 30 microhenrys, so time constant is more than 600 microseconds.This time is a long time relative to short circuiting transfer, under such major loop, the accurate control realizing short circuit current be do not have possible.
The major way of current solution power supply dynamic property as shown in Figure 3.This is a kind of source of welding current main circuit that can change loop time constant.One end of the positive output termination output inductor L of voltage follower circuit, one end of two termination power resistor R of output inductor L and the colelctor electrode C pole of current switching power switch pipe Q2, two ends of power resistor R are connected as the positive output end of the source of welding current with the emitter E of power switched switching tube Q2, external welding wire.The negative output terminal of voltage follower circuit as the negative output terminal of power supply, external welding base metal.When arc burning, as shown in t1 in Fig. 1 a-Fig. 1 c, current switching power switch pipe Q2 conducting, power resistor R is by short circuit.After short circuit occurs, as the t2 moment in Fig. 1 a-Fig. 1 c, current switching power switch pipe Q2 turns off, the now impedance in loop determines primarily of power resistor R, its resistance is generally more than 1 Europe, so the time constant in loop is reduced to tens of microseconds, power supply has enough dynamic response performances, electric current can be reduced to about below 40A very soon, and this electric current can be avoided splashing and produce.When molten drop is after weld pool surface is sprawled, as shown in t3 in Fig. 1 a-Fig. 1 c, again open current switching power switch pipe Q2, now the output voltage of regulation voltage output circuit (1) can make short circuit current rise rapidly.When detect the short circuit later stage foot bridge produce, will quick-fried disconnected time, cut-off current power switched switching tube Q2 again, as shown in t4 in Fig. 1 a-Fig. 1 c, electric current declines rapidly again.When foot bridge is broken by surface tension, after electric arc is set up again, open current switching power switch pipe Q2, the output voltage of regulation voltage output circuit (1) can make electric current rise rapidly, for electric arc provides suitable energy, as shown in t6 in Fig. 1 a-Fig. 1 c, thus start next cycle.In this circuit, due to the power resistor R that connected in loop, significantly can reduce the time constant of circuit, thus realize the accurate control to electric current.But in this circuit when needs reduce electric current, the energy of filter inductance L almost all consumes on power resistor R, and the power consumption of this resistance is very large.The more important thing is, because short circuit later stage electric current is very large, such as, when using diameter to be 1.2 millimeters of solid core welding wires, short circuit peak is about about 550A, what now power switched switching tube Q2 turned off is instantaneous, with the resistance of power resistor R be 1 Europe calculate, its transient power reaches more than 300 kilowatts, and trouble free service can be very difficult.If the volume of undue increasing power resistance R, its equivalent inductive reactance may be caused again excessive and affect the trouble free service of current switching power switch pipe Q2.And almost consume completely due to the energy of filter inductance L, when needs increase rapidly electric current, inductive current needs to rise from very low numerical value, may cause causing current interruption not in time because arc energy supplements.
Summary of the invention
The object of the invention is to: solve in circuit time constant handoff procedure, the problem that series resistance power consumption is excessive; The dynamic response performance of further raising power supply.By on the electric power main circuit basis that can change loop time constant, increase an energy and keep loop, the energy for filter inductance L provides a new flow cycle.When needs reduce rapidly electric power outputting current, the present invention does not need to reduce the electric current in inductance, but branched to other loop, so both can reduce electric power outputting current within the shortest time, can reduce again the power consumption on Series power resistance R, the security of resistance R is improved significantly.Because the energy loss in filter inductance L is less, when power supply needs to increase output current, switched by output loop impedance, the electric current of filter inductance L can be made directly to export from power supply, the rate of climb of electric power outputting current can reach 50 peaces/microsecond, drastically increases dynamic response performance.
The present invention adopts following technological means to realize:
A kind of welding supply with energy maintenance loop comprises: adjustable voltage output circuit (1), power switch pipe Q1 drive circuit (3), current switching power switch pipe Q2 drive circuit (4), source current feedback filtering circuit (6), supply voltage feedback filtering circuit (7), core control circuit (8), man-machine interaction circuit (9), is characterized in that also being provided with the source of welding current main circuit (2) having energy and keep loop, the described energy that has keeps the source of welding current main circuit (2) in loop to comprise energy maintenance power switch pipe Q1, energy keeps diode D1, output inductor L, current switching power switch pipe Q2, with power resistor R, one end and the energy of output inductor L keep the emitter E of power switch pipe Q1 to be extremely connected, colelctor electrode C pole and the energy of Q1 keep the negative electrode K of diode D1 to be extremely connected, two ends of output inductor L and energy keep the anode A pole of diode D1, one end of power resistor R, and the colelctor electrode C of current switching power switch pipe Q2 is extremely connected, two ends of power resistor R are extremely connected with the emitter E of current switching power switch pipe Q2, this end is as the output of circuit (2), external welding wire, an output of described adjustable voltage output circuit (1) keeps the emitter E of power switch pipe Q1 to be extremely connected with the energy of source of welding current main circuit (2), and another output connects mother metal, and welding arc builds between welding wire and mother metal.Adjustable voltage output circuit (1) provides adjustable voltage to source of welding current main circuit (2), energy in described source of welding current main circuit (2) keeps the base stage of power switch pipe Q1 to be connected with power switch pipe Q1 drive circuit (3), control by power switch pipe Q1 drive circuit (3), the base stage of current switching power switch pipe Q2 is connected with current switching power switch pipe Q2 drive circuit (4), controls by electric current power switched switching tube Q2 drive circuit (4); Described source current feedback filtering circuit (6) for the current feedback signal filtering flowing through arc load, and is sent to core control circuit (8); Described supply voltage feedback filtering circuit (7) for the filtering of arc load voltage feedback signal, and is sent to core control circuit (8); Core control circuit (8) energy controlled in source of welding current main circuit (2) keeps the break-make of power switch pipe Q1 and current switching power switch pipe Q2, and described man-machine interaction circuit (9) is for setup parameter.
The output voltage range of described adjustable voltage output circuit (1) is 0V-85V, and output current scope is 10-650A.
There is the source of welding current control method that energy keeps loop, specifically comprise:
When short circuit later stage foot bridge is formed, cut-off current power switched switching tube Q2, opens energy simultaneously and keeps power switch pipe Q1;
When the short circuit later stage, foot bridge was pulled off, open current switching power switch pipe Q2, turn off energy and keep power switch pipe Q1.
When short circuit initial stage foot bridge is formed, cut-off current power switched switching tube Q2, opens energy simultaneously and keeps power switch pipe Q1;
When the short circuit initial stage, foot bridge formed rear t millisecond, 0<t<1.5, opens current switching power switch pipe Q2, turns off energy simultaneously and keeps power switch pipe Q1.
Welding process is a cyclic process be made up of arc burning stage, short-circuit stage, arc burning stage.By there being two important moment in the arc burning stage to the process of short-circuit stage, be exactly the formation moment of short circuit initial stage foot bridge, and short circuit initial stage foot bridge forms moment t(ms) after, 0<t<1.5.When short circuit initial stage foot bridge is formed, if the electric current flowing through short circuit initial stage foot bridge is comparatively large, then easily causes quick-fried disconnected, thus produce splashing, so need to reduce welding current rapidly in this moment, avoid short circuit initial stage foot bridge quick-fried disconnected, suppress generation of splashing.Because short circuit initial stage electric current reduces, cause electromagnetic contractile force not enough, so when short circuit initial stage foot bridge forms moment t(ms) after, after namely molten drop is sprawled in molten bath, electric current should be increased rapidly, impel necking down to produce, prevent the appearance of solid short circuit.By also there are two important moment in short-circuit stage to the process in arc burning stage, i.e. the moment that the formation moment of short circuit later stage foot bridge, and short circuit later stage foot bridge is pulled off.When detecting that short circuit later stage foot bridge produces, reducing electric current rapidly, the generation of splashing can be avoided.After the short circuit later stage, foot bridge was pulled off under capillary effect, electric arc is set up again, and now electric current is very little, needs to increase electric current rapidly, ensures that electric arc has enough energy.
A kind of welding supply that there is energy and keep loop, comprise voltage follower circuit (11), power switch pipe Q1 drive circuit (3), current switching power switch pipe Q2 drive circuit (4), source current feedback filtering circuit (6), supply voltage feedback filtering circuit (7), core control circuit (8), man-machine interaction circuit (9), inductor current feedback filter circuit (10), characterized by further comprising the source of welding current main circuit (2) that there is energy and keep loop, the described energy that has keeps the source of welding current main circuit (2) in loop to comprise chopped power switching tube (Q1), fly-wheel diode (D2), energy keeps diode (D1), output inductor (L), current switching power switch pipe (Q2), with power resistor R.Colelctor electrode C and the energy of chopped power switching tube Q1 keep the negative electrode K of diode D1 to be connected, the emitter E of chopped power switching tube Q1 and the negative electrode K of sustained diode 2, and one end of output inductor L is connected, two ends of output inductor L and one end of power resistor R, energy keeps the anode A of diode D1, and the colelctor electrode C of current switching power switch pipe Q2 is connected, the other end of power resistor R is connected with the emitter E of current switching power switch pipe Q2, this end as the positive output end of circuit (2), external welding wire; The negative output terminal of circuit (1) is connected with the anode A of sustained diode 2 in circuit (2), as the output of circuit (2) while of this end, and external welding base metal; The colelctor electrode C of chopped power switching tube Q1 and the negative electrode K of energy maintenance diode D1 in the positive output end connection circuit (2) of circuit (1); Source current feedback filtering circuit (6) for the current feedback signal filtering flowing through arc load, and is sent to core control circuit (8); Supply voltage feedback filtering circuit (7) for the output voltage feedback signal filtering to circuit (2), and is sent to core control circuit (8); Inductor current feedback filter circuit (10) for the current feedback signal filtering flowing through output inductor (L), and is sent to core control circuit (8); Chopped power switching tube Q1 in core control circuit (8) control source of welding current main circuit (2) and the break-make of current switching power switch pipe Q2, described man-machine interaction circuit (9) is for setup parameter.
The output voltage range of described voltage follower circuit (11) is 14V-85V, and output current scope is 10-650A.
There is the source of welding current control method that energy keeps loop, specifically comprise:
When short circuit later stage foot bridge is formed, cut-off current power switched switching tube Q2, chopped power switching tube Q1 control flow check crosses the electric current of filtering inductance L;
When short circuit later stage foot bridge is stretch-broken between short circuit initial stage foot bridge formed again, open current switching power switch pipe Q2, chopped power switching tube Q1 controls the decrease speed of arcing current.
When short circuit initial stage foot bridge is formed, cut-off current power switched switching tube Q2, opens chopped power switching tube Q1 simultaneously;
T millisecond after the short circuit initial stage, foot bridge was formed, 0<t<1.5, between being formed to short circuit later stage foot bridge, open current switching power switch pipe Q2, chopped power switching tube Q1 controls the rate of climb of short circuit current.
In the present invention, when current switching power switch pipe Q2 opens or turns off, the rising of load current and decrease speed are all much larger than the variable time constant chopper circuit of routine.
beneficial effect
Supply unit of the present invention, when needs reduce rapidly output current, electric current in output inductor L is bypassed to other loop, instead of as conventional variable time constant electric power main circuit, inductance energy consumption on Series power resistance R, so the loss of power resistor R significantly reduces, the voltage peak on current switching power switch pipe Q2 also reduces thereupon, improves the reliability of Series power resistance R and current switching power switch pipe Q2.In addition, realize because the rapid rising of load current and decline are switched by circuit, so speed quickly, this time is equal to the switching speed of power switched switching tube Q2 substantially, so the dynamic property of power supply increases substantially.The current variation speeds of conventional variable time constant electric power main circuit is at 10 peaces/microseconds, and current variation speeds of the present invention can reach more than 50 peaces/microsecond.
Accompanying drawing explanation
Fig. 1 a-c is ideal short-cut current-voltage waveform and droplet transfer process schematic
Wherein Fig. 1 a is the desired voltage waveform of short circuiting transfer,
Fig. 1 b is the ideal current waveform of short circuiting transfer,
Fig. 1 c is ideal short-cut transient process droplet transfer process schematic.
Fig. 2 is normal welding electric power main circuit;
Fig. 3 is the source of welding current main circuit that can change loop time constant;
Fig. 4 is the overall system architecture figure of the first embodiment;
Fig. 5 a-f is the fundamental diagram of the first embodiment
Wherein Fig. 5 a is power switch pipe Q2 conducting, and Q1 turns off, Q3, Q5 conducting, current loop when Q4, Q6 turn off
Fig. 5 b is power switch pipe Q2 conducting, and Q1 turns off, current loop when Q3, Q5, Q4, Q6 turn off
Fig. 5 c is power switch pipe Q2 conducting, and Q1 turns off, and Q3, Q5 turn off, current loop during Q4, Q6 conducting
Fig. 5 d is that inductive current is comparatively large, and Q2 turns off, Q1 conducting, and Q3, Q5 turn off, current loop during Q4, Q6 conducting
Fig. 5 e is that inductive current is less, and Q2 turns off, Q1 conducting, and Q3, Q5 turn off, current loop during Q4, Q6 conducting
Fig. 5 f is that power switch pipe Q2 turns off, Q1 conducting, current loop when Q3, Q5, Q4, Q6 turn off
Fig. 6 is a kind of chopper-type adjustable voltage output circuit based on Industrial Frequency Transformer
Fig. 7 is a kind of chopper-type adjustable voltage output circuit based on generator
Fig. 8 is a kind of adjustable voltage output circuit based on thyristor rectifier rectifier
Fig. 9 is a kind of adjustable voltage output circuit based on generator
Figure 10 is a kind of adjustable voltage output circuit based on band tap Industrial Frequency Transformer
Figure 11 is the entire system mechanism map of the second embodiment
Figure 12 a-d is the fundamental diagram of the second embodiment
Wherein Figure 12 a is power switch pipe Q2 conducting, the current loop of Q1 also conducting
Figure 12 b is power switch pipe Q2 conducting, the current loop that Q1 turns off
Figure 12 c is that power switch pipe Q2 turns off, the current loop of Q1 conducting
Figure 12 d is that power switch pipe Q2 turns off, the current loop that Q1 also turns off
Figure 13 is the first technical scheme theory diagram of the present invention.
Fig. 2,3,4,5,7,8,9,10,11,12, in 13: Q1, Q2, Q3, Q4, Q5, Q6---power switch pipe, D1, D2, D3---diode, L---filter inductance, R---power resistor.TR---Industrial Frequency Transformer, TRH---intermediate-frequency transformer, Fig. 4, in 12: LEM1---voltage sensor, LEM2, LEM3---current sensor, (1) adjustable voltage output circuit, (2) there is the source of welding current main circuit that energy keeps loop, (3) power switch pipe Q1 drive circuit, (4) current switching power switch pipe Q2 drive circuit, (5) voltage follower circuit power switch tube drives circuit, (6) source current feedback filtering circuit, (7) supply voltage feedback filtering circuit, (8) core control circuit, (9) man-machine interaction circuit, (10) inductor current feedback filter circuit, (11) voltage follower circuit.
Detailed description of the invention
embodiment one:
Be illustrated in figure 4 the system construction drawing of embodiment of the present invention one, below in conjunction with accompanying drawing and specific embodiments, the present invention is described in further detail: adjustable voltage output circuit (1), power switch pipe Q1 drive circuit (3), current switching power switch pipe Q2 drive circuit (4), voltage follower circuit power switch tube drives circuit (5), source current feedback filtering circuit (6) in the present invention, supply voltage feedback filtering circuit (7), core control circuit (8), man-machine interaction circuit (9) belong to prior art.Described adjustable voltage output circuit (1) is by three-phase commutation bridge BR, and input filter capacitor C, voltage follower circuit power switch pipe Q3, Q4, Q5, Q6, intermediate-frequency transformer TRH, commutation diode D2, D3 form.Adjustable voltage output circuit (1) is as long as can export the DC voltage of 0-85V, different according to the requirement of welder power, the maximum 650A of output current capacity.This circuit can pass through half-bridge inversion circuit, push-pull inverter circuit equally, or the acquisition such as single-ended inverter circuit; Also the voltage follower circuit etc. of the chopper-type voltage follower circuit based on Industrial Frequency Transformer, the chopper-type voltage follower circuit based on generator, the voltage follower circuit based on silicon controlled rectifier, the voltage follower circuit based on generator or the Industrial Frequency Transformer based on band tap can be adopted.
The described source of welding current main circuit (2) with energy maintenance loop keeps power switch pipe Q1 by energy, and energy keeps diode D1, and output inductor L, power resistor R, current switching power switch pipe Q2 forms.Because energy keeps power switch pipe Q1 generally to adopt high-power insulated gate gate pole bipolar transistor (IGBT), this kind of device general inner reverse parallel connection diode, so need the energy maintenance diode D1 that connects in circuit, its effect prevents electric current from keeping flowing counterflow through of power switch pipe Q1 from energy.If energy keeps power switch pipe Q1 to adopt other high power device, can reverse-conducting be avoided, then can keep diode D1 without energy herein.
There is energy and keep welding supply embodiment one system in loop as shown in Figure 4.The U of three-phase alternating current, V, W three-phase is connected to three input one end, two ends of three-phase commutation bridge BR respectively, and three ends.One end of positive output end four termination input filter capacitor C, the colelctor electrode C of adjustable voltage output circuit (1) power switch pipe Q3 and Q6 of three-phase commutation bridge BR hold.The negative output terminal five terminal of three-phase commutation bridge BR connects two ends of filter capacitor C, the emitter E pole of adjustable voltage output circuit (1) power switch pipe Q4 and Q5.The emitter E pole of adjustable voltage output circuit (1) power switch pipe Q3 is connected with input one end of the colelctor electrode C pole of Q4, intermediate-frequency transformer TRH.The colelctor electrode C pole of adjustable voltage output circuit (1) power switch pipe Q5 is connected with input two end of the emitter E pole of Q6, intermediate-frequency transformer TRH.Output three end of intermediate-frequency transformer TRH is extremely connected with the anode A of commutation diode D2, the output five terminal of intermediate-frequency transformer TRH is extremely connected with the anode A of commutation diode D3, the negative electrode of commutation diode D2 with D3 is connected, this terminal, as the positive output end of adjustable voltage output circuit (1), connects the one end of the output inductor L in the source of welding current main circuit (2) with energy maintenance loop and the emitter E pole of energy maintenance power switch pipe Q1.Energy keeps the colelctor electrode C pole of power switch pipe Q1 and energy to keep the negative electrode K of diode D1 to be extremely connected.Two ends of output inductor L and energy keep the anode A pole of diode D1, and one end of power resistor R is extremely connected with the colelctor electrode C of current switching power switch pipe Q2.Two ends of power resistor R are extremely connected with the emitter E of current switching power switch pipe Q2, this end as the positive output end of circuit (2), external welding wire.Centre cap output four end of intermediate-frequency transformer secondary as the negative output terminal of circuit (1), simultaneously also as the negative output terminal of circuit (2), external welding base metal.One end and three ends of intermediate-frequency transformer TRH are Same Name of Ends.
Power switch pipe Q1 drive circuit (3) is made up of IGBT special driving chip M57962, current switching power switch pipe Q2 drive circuit (4) is made up of IGBT special driving chip M57962, source current feedback filtering circuit (6) is made up of low pass filter, supply voltage feedback filtering circuit (7) is made up of low pass filter, core control circuit (8) is made up of PIC30f2020 etc., and man-machine interaction circuit (9) is made up of the display circuit such as LED or LCD of routine and the circuit such as keyboard, encoder.Below in conjunction with the droplet transfer process of short circuit transition, the course of work of power supply is described.
In adjustable voltage output circuit (1), power switch pipe Q3, Q5 conducting simultaneously, power switch pipe Q4, Q6 conducting simultaneously.The turn-on instant of Q3, Q5 and Q4, Q6 is anti-phase, phase 180 degree.By controlling the turn-on and turn-off of adjustable voltage output circuit (1) power switch pipe, regulate the output voltage of adjustable voltage output circuit (1), thus the size of regulating load electric current, make it to change according to desirable waveform.In short circuit transition, load voltage judges short circuit whether key index.General when load voltage is greater than certain critical value, think that welding process is in arcing state, when load voltage is lower than this value, think that welding process is in short-circuit condition.According to the difference of welding average current, judge that the critical value of short-circuit voltage is generally between 10-20V.
When welding process is in arcing state, now arc voltage judges critical voltage higher than short circuit.Welding process is in arc stage, and now energy keeps power switch pipe Q1 to turn off, current switching power switch pipe Q2 conducting.Because the conduction voltage drop of current switching power switch pipe Q2 is lower, negligible, so now the operation principle of power supply is identical with conventional full bridge inverter circuit.
During arcing state, as adjustable voltage output circuit (1) switching tube Q3, Q5 conducting, when Q4, Q6 turn off, as shown in Fig. 5 (a).Intermediate-frequency transformer TRH primary current flows out from positive output end four end of three-phase commutation bridge BR, through power switch pipe Q3, flow into from one end, former limit of intermediate-frequency transformer TRH, flow out from former limit two end, through power switch pipe Q5, finally flow back to from the negative terminal five terminal of three-phase commutation bridge BR.The secondary current of intermediate-frequency transformer TRH flows out from three ends, and through commutation diode D2, output inductor L, current switching power switch pipe Q2, through welding arc load, finally enter centre cap four end of intermediate-frequency transformer TRH.
When adjustable voltage output circuit (1) switching tube all turns off, as shown in Fig. 5 (b).Intermediate-frequency transformer TRH primary current is zero, the output inductor L of secondary exports energy, electric current flows out from two ends of output inductor L, through current switching power switch pipe Q2, through arc load, enter the centre cap of intermediate-frequency transformer TRH secondary, through commutation diode D2 and D3 afterflow, finally flow back to one end of filter inductance L.
As adjustable voltage output circuit (1) switching tube Q4, Q6 conducting, when Q3, Q5 turn off, as shown in Fig. 5 (c).Intermediate-frequency transformer TRH primary current flows out from positive output end four end of three-phase commutation bridge BR, through power switch pipe Q6, flow into from former limit two end of intermediate-frequency transformer TRH, flow out from one end, former limit, through power switch pipe Q4, finally flow back to from the negative terminal five terminal of three-phase commutation bridge BR.The secondary current of intermediate-frequency transformer TRH flows out from five terminal, and through commutation diode D3, filter inductance L, current switching power switch pipe Q2, through welding arc load, finally enter centre cap four end of intermediate-frequency transformer TRH.
As can be seen from above process, when energy keeps power switch pipe Q1 to turn off, current switching power switch pipe Q2 conducting phase, the operation principle of this circuit is identical with the operation principle of conventional full bridge inverter.If the crest voltage of intermediate-frequency transformer TRH secondary is US, when the power switch pipe conducting on former limit, adjustable voltage output circuit (1) exports DC voltage US, and when former limit power switch pipe turns off, adjustable voltage output circuit (1) output voltage is zero.
When molten drop and molten bath are short-circuited, load voltage sharply declines, and judges critical value lower than short circuit, then think that short circuit initial stage foot bridge is formed, now cut-off current power switched switching tube Q2, opens energy simultaneously and keeps power switch pipe Q1.When adjustable voltage output circuit (1) power switch pipe conducting, adjustable voltage output circuit (1) output amplitude is the voltage of US, having energy keeps the electric current part in the source of welding current main circuit (2) in loop to flow through power resistor R, its current amplitude is US/R, remainder flows through energy and keeps diode D1 and energy to keep power switch pipe Q1, and its current loop is as shown in Fig. 5 (d).Because energy keeps diode D1 and energy to keep the pressure drop of power switch pipe Q1 lower, so the energy of L is kept in filter inductance, instead of consumed by power resistor R.If the electric current now flowing through inductance is less, be less than US/R, then current loop as shown in Figure 5 (e) shows.When adjustable voltage output circuit (1) power switch pipe turns off, intermediate-frequency transformer TRH and filter inductance L can not export energy, and the output current of power supply is zero.Its current loop is as Fig. 5 (f).
When the short circuit initial stage, foot bridge formed rear t millisecond, 0<t<1.5ms.Molten drop is sprawled at weld pool surface, needs rapid increase of weld current.Now open current switching power switch pipe Q2, turn off energy and keep power switch pipe Q1.By controlling the turn-on and turn-off of power switch pipe in adjustable voltage output circuit (1), the rate of climb of short circuit current can be controlled.The operation principle of the same conventional full bridge inverter of power work principle in this stage.Its current loop as in Fig. 5 (a), (b), or shown in (c).
When short circuit later stage foot bridge is formed, now short-circuit process closes to an end.The detection of this state adopts prior art, can be judged, also can be judged by the differential signal of test load impedance by the differential signal of test weld load voltage.In order to avoid the generation of splashing greatly, short circuit current should be reduced rapidly.Now cut-off current power switched switching tube Q2, opens energy and keeps power switch pipe Q1.Because short circuit later stage electric current is larger, when adjustable voltage output circuit (1) power switch pipe conducting, adjustable voltage output circuit (1) output amplitude is the voltage of US, an electric current part in output inductor L flows through power resistor R, its current amplitude is US/R, remainder flows through energy and keeps diode D1 and energy to keep power switch pipe Q1, and its current loop is as shown in Fig. 5 (d).Because energy keeps diode D1 and energy to keep the pressure drop of power switch pipe Q1 lower, so the energy in filter inductance L is kept, instead of consumed by power resistor R completely.When adjustable voltage output circuit (1) power switch pipe turns off, intermediate-frequency transformer TRH and filter inductance L can not export energy, and the output current of power supply is zero.Its current loop is as Fig. 5 (f).
When short circuit foot bridge is pulled off under capillary effect, the Rule of judgment of this state is that load voltage is greater than short circuit and judges critical voltage, turns off energy and keeps power switch pipe Q1, open current switching power switch pipe Q2.Then new cycle is started.
In the present invention, when current switching power switch pipe Q2 opens or turns off, the rising of the output current of supply unit of the present invention and decrease speed are all much larger than the variable time constant chopper circuit of routine
The output voltage range of adjustable voltage output circuit (1) is 0V-85V, and average voltage scope is 0-45V, and output current scope is 10-650A.The resistance of power resistor R is 1-3 Europe.
As shown in Figure 4, LEM1 is isolated voltage sensor, is parallel to the output of circuit (2), for the output voltage values of testing circuit (2).If the length of outside weldings cable is very long, then this sensor can directly be parallel on the nearest welding circuit parts of distance welding arc.Supply voltage feedback filtering circuit (7) is positioned between LEM1 and core control circuit (8).LEM2 is isolated current sensor, for detecting electric power outputting current.Source current feedback filtering circuit (6) is positioned between LEM2 and core control circuit (8).Power switch pipe Q1 drive circuit (3) is positioned at core control circuit (8) and energy keeps between power switch pipe Q1, and current switching power switch pipe Q2 drive circuit (4) is positioned between core control circuit (8) and current switching power switch pipe Q2.Core control circuit (8) is connected with man-machine interaction circuit (9), for arranging the output parameter of power supply.
Pulse width modulation (Pluse Width Modulation is adopted in the present embodiment, be called for short PWM) control technology, control adjustable voltage output circuit (1) power switch pipe Q3 by voltage follower circuit power switch tube drives circuit (5), Q4, the conducting of Q5, Q6 and shutoff.By adjustment pulse duty factor, the output current in welding process can be controlled.Control conducting and shutoff that current switching power switch pipe Q2 and energy keep power switch pipe Q1, namely can the impedance in Switching power loop, reach the object changing power supply dynamic property.
In the course of the work, the output voltage of voltage sensor LEM1 to circuit (2) is sampled, and the output current of current sensor LEM2 to circuit (2) is sampled.Sampled result is given core control circuit (8), the parameter that sampled result and man-machine interaction circuit (9) set is compared computing by core control circuit (8) respectively, transmission of signal is to voltage follower circuit power switch tube drives circuit (5), power switch pipe Q1 drive circuit (3), current switching power switch pipe Q2 drive circuit (4), the turn-on and turn-off of regulating power switching tube Q1, Q2, Q3, Q4, Q5, Q6 respectively, finally realize output current and voltage parameter is equal with human-computer exchange circuit (9) setting value respectively.
In overall structure figure shown in Fig. 4, adjustable voltage output circuit (1) also can adopt the chopper-type circuit based on Industrial Frequency Transformer as shown in Figure 6.The U of three-phase electricity, V, W connect three input one end of three-phase main-frequency transformer TR respectively, two ends, and three ends.Three output four ends of three-phase main-frequency transformer TR, five terminal, and six ends connect three input one end of three-phase commutation bridge BR respectively, two ends, and three ends.One end of positive output end four termination filter capacitor C and the colelctor electrode C of power switch pipe Q3 of three-phase commutation bridge BR hold.Power switch pipe Q3 now plays the effect of chop control.The emitter E end of power switch pipe Q3 is connected with the negative electrode K end of sustained diode 2.This end, as the positive output end of adjustable voltage output circuit (1), keeps the emitter E of power switch pipe Q1 to be connected with one end of filter inductance L with the energy in the source of welding current main circuit (2) in Fig. 4 with energy maintenance loop.The negative output terminal of three-phase commutation bridge BR and two ends of filter capacitor C, the anode A of sustained diode 2 is extremely connected, this end as the negative output terminal of adjustable voltage output circuit (1), simultaneously as the negative output terminal of circuit in Fig. 4 (2).Adjustable voltage output circuit shown in Fig. 6 is identical with the function of the adjustable voltage output circuit (1) shown in Fig. 4, it controls difference and is that the output current of control circuit in Fig. 4 (2) needs to control power switch pipe Q3 in adjustable voltage output circuit (1), the turn-on and turn-off of Q4, Q5 and Q6.And in figure 6, only need the turn-on and turn-off controlling power switch pipe Q3.
In overall structure figure shown in Fig. 4, adjustable voltage output circuit (1) also can adopt the chopper-type voltage follower circuit based on generator as shown in Figure 7.Three output one end of generator MOTO, two ends, and three ends connect three input one end of three-phase commutation bridge BR respectively, two ends, and three ends.One end of positive output end four termination filter capacitor C and the colelctor electrode C of power switch pipe Q3 of three-phase commutation bridge BR hold, and power switch pipe Q3 now plays the effect of chop control.The emitter E end of power switch pipe Q3 is connected with the negative electrode K end of sustained diode 2, this end, as the positive output end of adjustable voltage output circuit (1), keeps the emitter E pole of power switch pipe Q1 to be connected with one end of filter inductance with the energy in the electric power main circuit (2) in Fig. 4 with energy maintenance loop.The negative output terminal of three-phase commutation bridge BR and two ends of filter capacitor C, the anode A of sustained diode 2 is extremely connected, this end as the negative output terminal of adjustable voltage output circuit (1), simultaneously as the negative output terminal of circuit in Fig. 4 (2).Adjustable voltage output circuit shown in Fig. 7 is identical with the effect of the adjustable voltage output circuit (1) shown in Fig. 4, its difference controlled is that the output current of control circuit in Fig. 4 (2) needs to control power switch pipe Q3 in adjustable voltage output circuit (1), the turn-on and turn-off of Q4, Q5 and Q6.And in the figure 7, only need the turn-on and turn-off controlling power switch pipe Q3.
In overall structure figure shown in Fig. 4, adjustable voltage output circuit (1) also can adopt the voltage follower circuit based on silicon controlled rectifier as shown in Figure 8.The U of three-phase electricity, V, W connect three input one end of three-phase main-frequency transformer TR respectively, two ends, and three ends.Three output four ends of three-phase main-frequency transformer TR, five terminal, and six ends connect three input one end of three-phase controlled thyristor rectifier bridge BR respectively, two ends, and three ends.One end of the positive output end four termination filter capacitor C of three-phase controlled thyristor rectifier bridge BR is connected.This end, as the positive output end of adjustable voltage output circuit (1), keeps the emitter E pole of power switch pipe Q1 to be connected with one end of filter inductance with the energy in the electric power main circuit (2) in Fig. 4 with energy maintenance loop.The negative output terminal of three-phase controlled thyristor rectifier bridge BR is connected with two ends of filter capacitor C, this end as the negative output terminal of adjustable voltage output circuit (1), simultaneously as the negative output terminal of circuit in Fig. 4 (2).Adjustable voltage output circuit shown in Fig. 8 is substantially identical with the effect of the adjustable voltage output circuit (1) shown in Fig. 4, its difference controlled is that the output current of control circuit in Fig. 4 (2) needs to control power switch pipe Q3 in adjustable voltage output circuit (1), the turn-on and turn-off of Q4, Q5 and Q6.And in fig. 8, by controlling the output voltage of angle of flow control voltage output circuit of IGCT, the average voltage of electric arc in this voltage and welding process.Electric current rise and fall speed in welding process is determined by the induction reactance value of filter inductance L.Energy keeps the control of power switch pipe Q1 and current switching power switch pipe Q2 identical with in Fig. 4.
In overall structure figure shown in Fig. 4, adjustable voltage output circuit (1) also can adopt the voltage follower circuit based on generator as shown in Figure 9.Three output one end of generator MOTO, two ends, and three ends connect three input one end of three-phase commutation bridge BR respectively, two ends, and three ends.One end of the positive output end four termination filter capacitor C of three-phase commutation bridge BR is connected.This end, as the positive output end of adjustable voltage output circuit, keeps the transmitting of power switch pipe Q1 to amass E pole with the energy in the electric power main circuit (2) in Fig. 4 with energy maintenance loop and is connected with one end of filter inductance L.The negative output terminal of three-phase commutation bridge BR is connected with two ends of filter capacitor C, this end as the negative output terminal of adjustable voltage output circuit (1), simultaneously as the negative output terminal of circuit in Fig. 4 (2).Adjustable voltage output circuit shown in Fig. 9 is substantially identical with the effect of the adjustable voltage output circuit (1) shown in Fig. 4, its difference controlled is that the output current of control circuit in Fig. 4 (2) needs to control power switch pipe Q3 in adjustable voltage output circuit (1), the turn-on and turn-off of Q4, Q5 and Q6.And in fig .9, realized by the output voltage of adjustment generator MOTO.Electric current rise and fall speed in welding process is determined by the induction reactance value of filter inductance L.Energy keeps the control of power switch pipe Q1 and current switching power switch pipe Q2 identical with in Fig. 4.
In overall structure figure shown in Fig. 4, adjustable voltage output circuit (1) also can adopt the voltage follower circuit of the Industrial Frequency Transformer based on band tap as shown in Figure 10.The U of three-phase electricity, V, W are connected to three input one end of three-phase main-frequency transformer TR respectively, two ends, and three ends.Three output four ends of three-phase main-frequency transformer TR, five terminal, and six ends connect three input one end of three-phase commutation bridge BR respectively, two ends, and three ends.One end of the positive output end four termination filter capacitor C of three-phase commutation bridge BR is connected.This end, as the positive output end of adjustable voltage output circuit (1), keeps the emitter E pole of power switch pipe Q1 to be connected with one end of filter inductance L with the energy in the electric power main circuit (2) in Fig. 4 with energy maintenance loop.The negative output terminal of three-phase commutation bridge BR is connected with two ends of filter capacitor C, this end as the negative output terminal of adjustable voltage output circuit (1), simultaneously as the negative output terminal of circuit in Fig. 4 (2).
Adjustable voltage output circuit shown in Figure 10 is substantially identical with the effect of the adjustable voltage output circuit (1) shown in Fig. 4, the output current that its difference controlled is to control in Fig. 4 power supply needs to control power switch pipe Q3 in adjustable voltage output circuit (1), the turn-on and turn-off of Q4, Q5 and Q6.And in Fig. 10, realize by regulating the former limit number of turn of three-phase transformer TR.Electric current rise and fall speed in welding process is determined by the induction reactance value of filter inductance L.Energy keeps the control of power switch pipe Q1 and current switching power switch pipe Q2 identical with in Fig. 4.
embodiment two:
Have the welding supply that energy keeps function, its embodiment two system structure as shown in figure 11.This device comprises voltage follower circuit (11), power switch pipe Q1 drive circuit (3), current switching power switch pipe Q2 drive circuit (4), source current feedback filtering circuit (6), supply voltage feedback filtering circuit (7), core control circuit (8), man-machine interaction circuit (9), inductor current feedback filter circuit (10), also comprise the source of welding current main circuit (2) that there is energy and keep loop, the described energy that has keeps the source of welding current main circuit (2) in loop to comprise chopped power switching tube (Q1), fly-wheel diode (D2), energy keeps diode (D1), output inductor (L), current switching power switch pipe (Q2), with power resistor R.Colelctor electrode C and the energy of chopped power switching tube Q1 keep the negative electrode K of diode D1 to be connected, the emitter E of chopped power switching tube Q1 and the negative electrode K of sustained diode 2, and one end of output inductor L is connected, two ends of output inductor L and one end of power resistor R, energy keeps the anode A of diode D1, and the colelctor electrode C of current switching power switch pipe Q2 is connected, the other end of power resistor R is connected with the emitter E of current switching power switch pipe Q2, this end as the positive output end of circuit (2), external welding wire; The negative output terminal of circuit (1) is connected with the anode A of sustained diode 2 in circuit (2), as the negative output terminal of circuit (2) while of this end, and external welding base metal; The colelctor electrode C of chopped power switching tube Q1 in the positive output end connection circuit (2) of voltage follower circuit (11); Source current feedback filtering circuit (6) for the current feedback signal filtering flowing through arc load, and is sent to core control circuit (8); Supply voltage feedback filtering circuit (7) for the output voltage feedback signal filtering to circuit (2), and is sent to core control circuit (8); Inductor current feedback filter circuit (10) for the current feedback signal filtering flow through on output inductor L, and is sent to core control circuit (8); Chopped power switching tube Q1 in core control circuit (8) control source of welding current main circuit (2) and the break-make of current switching power switch pipe Q2, described man-machine interaction circuit (9) is for setup parameter.
LEM1 is isolated voltage sensor, for the magnitude of voltage of testing circuit (2) output.LEM1 detects the voltage feedback signal obtained and is input in core control circuit (8) after supply voltage feedback filtering circuit (7) process.LEM2 is isolated current sensor, for the current value that testing circuit (2) exports, namely flows through the current value of arc load.The current feedback signal that LEM2 detects enters in core control circuit (8) after source current feedback filtering circuit (6) process.LEM3 is isolated current sensor, flows through current value in output inductor L for detecting.LEM3 detects the current feedback signal obtained and is input in core control circuit (8) after inductor current feedback filter circuit (10) process.Core control circuit (8) controls the turn-on and turn-off of chopped power switching tube Q1 by power switch pipe Q1 drive circuit (3), and core control circuit (8) controls the turn-on and turn-off of power switched switching tube Q2 by current switching power switch pipe Q2 drive circuit (4).Core control circuit (8) is connected with man-machine interaction circuit (9), for arranging the output parameter of power supply.
Voltage follower circuit (11), power switch pipe Q1 drive circuit (3), current switching power switch pipe Q2 drive circuit (4), source current feedback filtering circuit (6), supply voltage feedback filtering circuit (7), core control circuit (8), man-machine interaction circuit (9) in the present invention, inductor current feedback filter circuit (10), belongs to prior art.Wherein voltage follower circuit (11) is as long as can export DC voltage, and ensures that its voltage magnitude is between 14-85V, different according to the requirement of welder power, the maximum 650A of output current capacity.This circuit can adopt AC transformer, after single-phase or the electric transformation of three-phase main-frequency, then exports after rectifying and wave-filtering; Also by conventional inverter circuit, as full bridge inverter, half-bridge inversion circuit, single-ended inverter circuit etc., single-phase or the electric low-voltage DC that converts to of three-phase main-frequency can be obtained; Generator can also be adopted to export alternating current, export after rectifying and wave-filtering; Powerful constant current or constant voltage source can also be adopted, output setting is adjusted to maximum, then coordinates capacitor filtering at output.Source current feedback filtering circuit (6) is made up of low pass filter, power switch pipe Q1 drive circuit (3) is made up of IGBT special driving chip M57962, inductor current feedback filter circuit (10) is made up of low pass filter, current switching power switch pipe Q2 drive circuit (4) is made up of IGBT special driving chip M57962, supply voltage feedback filtering circuit (7) is made up of low pass filter, core control circuit (8) is made up of PIC30f2020, man-machine interaction circuit (9) is by display circuit and the keyboard such as LED or LCD of routine, the circuit compositions such as encoder.
Operation principle of the present invention please refer to Figure 12 a-d.The operation principle of voltage follower circuit (11) is well-known, in order to express easily, in Figure 12 a-d, represents voltage follower circuit (11) with " voltage source ".
Said in embodiment one, in short circuit transition, load voltage judges short circuit whether key index.General when load voltage is greater than certain critical value, think that welding process is in arcing state, when load voltage is lower than this value, think that welding process is in short-circuit condition.According to the difference of welding average current, judge that the critical value of short-circuit voltage is generally between 10-20V.
When welding process is in arcing state, now arc voltage judges critical voltage higher than short circuit.Current switching power switch pipe Q2 keeps conducting.By controlling the turn-on and turn-off of chopped power switching tube Q1, can the size of control circuit (2) output current.During due to electric arc normal combustion, arc voltage generally can not higher than the output voltage of voltage source, so energy keeps diode D1 not possess turn-on condition, power work principle is now identical with conventional chopper circuit.When Q1 pipe turn-on and turn-off, the current loop of circuit is respectively as shown in Figure 12 a, Figure 12 b.
When short circuit initial stage foot bridge is formed, now molten drop and molten bath are short-circuited, and the output voltage of supply unit of the present invention is dragged down rapidly, lower than the critical voltage that short circuit judges.In order to ensure that molten drop can smoothly transit, current switching power switch pipe Q2 turns off, and chopped power switching tube Q1 conducting makes electric current remain on a lower value, and test shows if electric current is less than 40A, then can not produce splashing.Power resistor R is sealed in the major loop of power supply, and in inductance L, portion of electrical current flows through energy maintenance diode D1.Because the adjustment of load current is realized by current switching, so its pace of change quickly, the highlyest more than 50 peaces/microsecond can be reached.
After short circuit initial stage foot bridge forms t millisecond, 0<t<1.5, between being formed to short circuit later stage foot bridge, open current switching power switch pipe Q2, chopped power switching tube Q1 controls the rate of climb of short circuit current.This stage, molten drop is sprawled at weld pool surface, needs rapid increase of weld current, to promote that necking down produces, therefore current switching power switch pipe Q2 conducting, additionally by the rate of climb turning on and off control short circuit current controlling chopped power switching tube Q1.Current loop as depicted in figs. 12 a and 12b.
When short circuit later stage foot bridge is formed, short circuit current rises to a higher value.In order to avoid the generation of splashing, short circuit current should be reduced rapidly.The detection that short circuit later stage foot bridge forms state adopts prior art, can be judged, also can be judged by the differential signal of test load impedance by the differential signal of test weld load voltage.Now turn off power switched switch Q2, power resistor R is sealed in power supply major loop.Chopped power switching tube Q1 control flow check crosses the electric current of filtering inductance L.Because short circuit later stage electric current is comparatively large, the current segment in inductance flows through power resistor R, and remainder flows through energy and keeps diode D1.When chopped power switching tube Q1 opens, this electric current will flow back to inductance through chopped power switching tube Q1, and electric current remains unchanged substantially; When chopped power switching tube Q1 pipe closes, this electric current will flow back to inductance through voltage source and sustained diode 2, and now inductive current will decline.Current loop is as shown in Figure 12 c and Figure 12 d.
When short circuit later stage foot bridge is pulled off under capillary effect, electric arc re-establishes, and load voltage relative short-circuit voltage has obvious rising, judges critical voltage higher than short circuit.Be stretch-broken between short circuit initial stage foot bridge formed again at short circuit later stage foot bridge, open current switching power switch pipe Q2, chopped power switching tube Q1 controls the decrease speed of arcing current.Enter next cycle period afterwards.
In the present embodiment, when current switching power switch pipe Q2 opens or turns off, flow through the rising of the electric current of load and decrease speed all much larger than the variable time constant chopper circuit of routine, maximum speed can reach 50 peaces/microsecond.
In the present embodiment, the output voltage range of voltage follower circuit is 14-85V.The resistance of Series power resistance R is 1-3 Europe.The output current scope of power supply is 10-650A.
The present invention adopts pulse width modulation (Pluse Width Modulation is called for short PWM) control technology, controls conducting and the shutoff of chopped power switching tube Q1.Adjustment dutycycle, can control the output current in welding process.Control conducting and the shutoff of current switching power switch pipe Q2, namely can change the time constant of electric power loop, reach the object changing power supply dynamic property.
In the course of the work, supply voltage sensor LEM1 is used for the output voltage of feedback circuit (2), and source current sensor LEM2 is used for the output current of feedback circuit (2), and inductive current sensor LEM3 is for feeding back the electric current flowing through inductance.After feedback result being given core control circuit (8), the parameter that feedback result and man-machine interaction circuit (9) set is compared computing by core control circuit (8) respectively, transmission of signal is to chopped power switching tube Q1 drive circuit (3) and current switching power switch pipe Q2 drive circuit (4), the turn-on and turn-off of regulating power switching tube Q1, Q2 respectively, finally realize output current and voltage parameter is equal with man-machine interaction circuit (9) setting value respectively.
Claims (8)
1. a welding supply with energy maintenance loop comprises: adjustable voltage output circuit (1), power switch pipe Q1 drive circuit (3), current switching power switch pipe Q2 drive circuit (4), source current feedback filtering circuit (6), supply voltage feedback filtering circuit (7), core control circuit (8), man-machine interaction circuit (9), is characterized in that also being provided with the source of welding current main circuit (2) having energy and keep loop; The described energy that has keeps the source of welding current main circuit (2) in loop to comprise energy maintenance power switch pipe Q1, and energy keeps diode D1, output inductor L, current switching power switch pipe Q2, and power resistor R; One end and the energy of output inductor L keep the emitter E of power switch pipe Q1 to be extremely connected, colelctor electrode C pole and the energy of Q1 keep the negative electrode K of diode D1 to be extremely connected, two ends and the energy of filter inductance L keep the anode A pole of diode D1, one end of power resistor R and the colelctor electrode C of current switching power switch pipe Q2 to be extremely connected, two ends of power resistor R are extremely connected with the emitter E of current switching power switch pipe Q2, this end as the positive output end of circuit (2), external welding wire; An output of described adjustable voltage output circuit (1) keeps the emitter E of power switch pipe Q1 to be extremely connected with the energy of source of welding current main circuit (2), another output connects mother metal, and welding arc builds between welding wire and mother metal; Adjustable voltage output circuit (1) provides adjustable voltage to source of welding current main circuit (2), energy in described source of welding current main circuit (2) keeps the base stage of power switch pipe Q1 to be connected with power switch pipe Q1 drive circuit (3), control by power switch pipe Q1 drive circuit (3), the base stage of current switching power switch pipe Q2 is connected with current switching power switch pipe Q2 drive circuit (4), controls by electric current power switched switching tube Q2 drive circuit (4); Described source current feedback filtering circuit (6) for the current feedback signal filtering flowing through arc load, and is sent to core control circuit (8); Described supply voltage feedback filtering circuit (7) for the filtering of arc load voltage feedback signal, and is sent to core control circuit (8); Core control circuit (8) energy controlled in source of welding current main circuit (2) keeps the break-make of power switch pipe Q1 and current switching power switch pipe Q2, and described man-machine interaction circuit (9) is for setup parameter.
2. a kind of welding supply having energy and keep loop according to claim 1, is characterized in that: when short circuit later stage foot bridge is formed, cut-off current power switched switching tube Q2, opens energy simultaneously and keep power switch pipe Q1; When the short circuit later stage, foot bridge was pulled off, open current switching power switch pipe Q2, turn off energy and keep power switch pipe Q1.
3. a kind of welding supply having energy and keep loop according to claim 1, is characterized in that: when short circuit initial stage foot bridge is formed, cut-off current power switched switching tube Q2, opens energy simultaneously and keep power switch pipe Q1; When the short circuit initial stage, foot bridge formed rear t millisecond, 0<t<1.5, opens current switching power switch pipe Q2, turns off energy simultaneously and keeps power switch pipe Q1.
4. a kind of welding supply having energy and keep loop according to claim 1, is characterized in that: the output voltage range of described adjustable voltage output circuit (1) is 0V-85V, and output current scope is 10-650A.
5. the welding supply that there is energy and keep loop, comprise voltage follower circuit (11), power switch pipe Q1 drive circuit (3), current switching power switch pipe Q2 drive circuit (4), source current feedback filtering circuit (6), supply voltage feedback filtering circuit (7), core control circuit (8), man-machine interaction circuit (9), inductor current feedback filter circuit (10), characterized by further comprising the source of welding current main circuit (2) that there is energy and keep loop, the described energy that has keeps the source of welding current main circuit (2) in loop to comprise chopped power switching tube Q1, sustained diode 2, energy keeps diode D1, output inductor L, current switching power switch pipe Q2, with power resistor R, colelctor electrode C and the energy of chopped power switching tube Q1 keep the negative electrode K of diode D1 to be connected, the emitter E of chopped power switching tube Q1 and the negative electrode K of sustained diode 2, and one end of output inductor L is connected, two ends of output inductor L and one end of power resistor R, energy keeps the anode A of diode D1, and the colelctor electrode C of current switching power switch pipe Q2 is connected, the other end of power resistor R is connected with the emitter E of current switching power switch pipe Q2, this end as the positive output end of circuit (2), external welding wire, the negative output terminal of circuit (1) is connected with the anode A of sustained diode 2 in circuit (2), as the negative output terminal of circuit (2) while of this end, and external welding base metal, the colelctor electrode C of chopped power switching tube Q1 in the positive output end connection circuit (2) of voltage follower circuit (11), source current feedback filtering circuit (6) for the current feedback signal filtering flowing through arc load, and is sent to core control circuit (8), supply voltage feedback filtering circuit (7) for the output voltage feedback signal filtering to circuit (2), and is sent to core control circuit (8), inductor current feedback filter circuit (10) for the current feedback signal filtering flow through on output inductor (L), and is sent to core control circuit (8), chopped power switching tube Q1 in core control circuit (8) control source of welding current main circuit (2) and the break-make of current switching power switch pipe Q2, described man-machine interaction circuit (9) is for setup parameter.
6. a kind of welding supply having energy and keep loop according to claim 5, is characterized in that: when short circuit later stage foot bridge is formed, cut-off current power switched switching tube Q2, chopped power switching tube Q1 control flow check crosses the electric current of filtering inductance L; When short circuit later stage foot bridge is stretch-broken between short circuit initial stage foot bridge formed again, open current switching power switch pipe Q2, chopped power switching tube Q1 controls the decrease speed of arcing current.
7. a kind of welding supply having energy and keep loop according to claim 5, is characterized in that: when short circuit initial stage foot bridge is formed, cut-off current power switched switching tube Q2, opens chopped power switching tube Q1 simultaneously; T millisecond after the short circuit initial stage, foot bridge was formed, 0<t<1.5, between being formed to short circuit later stage foot bridge, open current switching power switch pipe Q2, chopped power switching tube Q1 controls the rate of climb of short circuit current.
8. a kind of welding supply having energy and keep loop according to claim 5, is characterized in that: the output area of described voltage follower circuit (11) is 14V-85V, and output current scope is 10-650A.
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| CN106513935A (en) * | 2016-12-30 | 2017-03-22 | 唐山松下产业机器有限公司 | Arcing state judgment method and device and electric arc welding device |
| CN111001902B (en) * | 2020-03-09 | 2020-07-07 | 杭州凯尔达电焊机有限公司 | Welding control circuit and alternating current welding power supply |
| CN114160925A (en) * | 2021-12-07 | 2022-03-11 | 深圳市麦格米特焊接技术有限公司 | Current blocking method and device, welding system and welding machine |
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| CN201287234Y (en) * | 2008-10-28 | 2009-08-12 | 上海沪工电焊机制造有限公司 | Numerical control soft-switch inversion welding power source of electric welding machine |
| CN101412139A (en) * | 2008-11-17 | 2009-04-22 | 江苏科技大学 | Inversion welding source under finite both positive control mode |
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