[utility model content]
It is big that the technical problems to be solved in the utility model provides a kind of power output, and volume is less; The high-frequency invert direct-current point-welding device that welding efficiency is high.
It is comparatively simple that the technical problem that the utility model further will solve provides a kind of control circuit, the high-frequency invert direct-current point-welding device that dynamic property is good, response speed is fast, control accuracy is high, welding quality is good.
The technical problem that the utility model further will solve provides a kind of little to the electrical network interference, and IGBT impacts little high-frequency invert direct-current point-welding device.
In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is, a kind of high-frequency invert direct-current point-welding device, comprise rectified three-phase circuit, inverter circuit, high frequency transformer, current rectifying and wave filtering circuit and dsp controller, described rectified three-phase circuit is transformed into direct current with three-phase alternating current, inverter circuit is reverse into high-frequency alternating current with the direct current commentaries on classics of rectified three-phase circuit output under the control of dsp controller, produce the pulsating direct current welding current by current rectifying and wave filtering circuit after the high frequency transformer step-down; The primary coil of described high frequency transformer and secondary coil layering replace coiling, between layer and the layer insulating barrier are arranged; The primary coil layer is clipped between the secondary wire ring layer, and the internal layer of primary coil layer and skin all have the secondary wire ring layer; Secondary coil thin copper belt layering coiling, every layer one circle; Described internal layer and outer field secondary wire ring layer all are even levels, and the secondary wire ring layer of internal layer is connected mutually, the current opposite in direction of adjacent layer; Outer field secondary wire ring layer is series connection mutually also, and the sense of current of adjacent layer is also opposite.
Above-described high-frequency invert direct-current point-welding device, described primary coil layer is 2 layers, 2 layers of primary coil layer are connected mutually; Every layer of primary coil layer has 2 layers of internal layer secondary wire ring layer and 2 layers of outer secondary wire ring layer, has 8 hierarchical level coil layer; The serial connection point of secondary coil adjacent layer all connects the centre cap of transformer output, and the end of the same name of each layer of secondary coil also connects, and connects the transformer output.
Above-described high-frequency invert direct-current point-welding device, described high frequency transformer are 2 to 4, all high frequency transformer parallel connections; The first no-load voltage ratio of high frequency transformer is 40-80:1; Described magnetic core is an E type magnetic core, and the magnetic core slit is the 0.2-0.8 millimeter, and the material of magnetic core is the Mn-Zn Ferrite Material; The primary coil stranded use of insulated copper wire of diameter 0.3-0.6 millimeter, the secondary coil electrolysis copper strips of thickness 0.3-0.6 millimeter; The thickness of insulating materials is 0.05 to 0.1 millimeter.
Above-described high-frequency invert direct-current point-welding device, the thin copper belt one of the pin of secondary coil and secondary coil is folded into after drawing from each secondary wire ring layer on the plane with the transformer axis normal.
Above-described high-frequency invert direct-current point-welding device, comprise first current feedback circuit and second voltage feedback circuit, described first current feedback circuit and second voltage feedback circuit are imported sampled value respectively the signal input part of dsp controller from the output sampling of current rectifying and wave filtering circuit; Described inverter circuit comprises IGBT bridge circuit on-off circuit and isolated drive circuit; Described dsp controller produces 4 road pwm signals, through the break-make of isolated drive circuit control IGBT bridge circuit on-off circuit.
Above-described high-frequency invert direct-current point-welding device comprises the 3rd current feedback circuit, and described the 3rd current feedback circuit is imported sampled value the signal input part of dsp controller from the output sampling of inverter circuit.
Above-described high-frequency invert direct-current point-welding device comprises the 4th current feedback circuit, and described the 4th current feedback circuit is imported sampled value the signal input part of dsp controller from the output sampling of rectified three-phase circuit.
Above-described high-frequency invert direct-current point-welding device, described rectified three-phase circuit is followed successively by electromagnetic compatibility circuit, three-phase alternating current rectification circuit, soft starting circuit and current rectifying and wave filtering circuit, described electromagnetic compatibility circuit absorbs the due to voltage spikes that suppresses on the three-phase alternating current bus, reduces electromagnetic interference; Described three-phase alternating current rectification circuit is converted to direct current with the three-phase alternating current of electromagnetic compatibility circuit output; Described current rectifying and wave filtering circuit comprises filter capacitor, and the direct current that the three-phase alternating current rectification circuit is exported carries out filtering; Described soft starting circuit control three-phase alternating current rectification circuit output major loop just makes the major loop energising after described filter capacitor charges to busbar voltage.
Above-described high-frequency invert direct-current point-welding device, electromagnetic compatibility circuit are in series with input inductance respectively on the phase line of three-phase electricity, be parallel with peak clipping electric capacity between phase line respectively.
Above-described high-frequency invert direct-current point-welding device, described soft starting circuit comprises charging resistor, controllable silicon and soft start control panel, described controllable silicon is connected on the three-phase alternating current rectification circuit output major loop, described charging resistor is in parallel with controllable silicon, and described soft start control panel is opened the time of time-delay and the Control of Voltage silicon controlled break-make of described filter capacitor according to complete machine.
The primary coil and the secondary coil layering of the utility model high-frequency invert direct-current point-welding device high frequency transformer replace coiling, the primary coil layer is clipped between the secondary wire ring layer, the internal layer of primary coil layer and skin all have the secondary wire ring layer, secondary coil thin copper belt layering coiling, every layer one circle, be convenient to like this transformer coiling, can reduce volume, reduce leakage inductance, reduce copper path loss consumption, be convenient to the derivation of secondary heat, help bigger electric current of high frequency transformer and mash welder output and higher power, improve welding efficiency.
The utility model such as further employing are finished by feedback circuit DSP inside pulse width signal are controlled, thereby reach the purpose of constant current, constant voltage and the control of permanent power of complete machine, make control circuit comparatively simple, dynamic property is good, response speed is fast, control accuracy is high, welding quality is better.
Rectified three-phase circuit of the present utility model comprises that further electromagnetic compatibility circuit and soft starting circuit can reduce to the interference of electrical network with to the impact of IGBT.
[specific embodiment]
In the circuit of the embodiment of the utility model high-frequency invert direct-current point-welding device as shown in Figure 1, comprise rectified three-phase circuit, inverter circuit, high frequency transformer, current rectifying and wave filtering circuit and dsp controller.Rectified three-phase circuit comprises electromagnetic compatibility circuit 1, three-phase alternating current rectification circuit 2, soft starting circuit 3 and current rectifying and wave filtering circuit 4, and inverter circuit comprises IGBT isolated drive circuit 5, IGBT bridge circuit on-off circuit 6 and IGBT accessory power supply 9.The electricity of the interchange of three-phase 50HZ is transformed into direct current through electromagnetic compatibility circuit 1, three-phase alternating current through rectification circuit 2, soft starting circuit 3 and current rectifying and wave filtering circuit 4, the pwm control signal that DSP produces is through isolated drive circuit, the break-make of control IGBT, the direct current commentaries on classics of current rectifying and wave filtering circuit 4 outputs is reverse into high-frequency alternating current, but after the high frequency transformer step-down of 2 to 4 parallel connections, produces the pulsating direct current welding current of spot welding by current rectifying and wave filtering circuit.
The structural principle of the embodiment high frequency transformer of the utility model high-frequency invert direct-current point-welding device and profile such as Fig. 2 are to shown in Figure 5.
The external form of magnetic core is an E type magnetic core, and material is the M of H30
n-Z
nFerrite Material, saturation flux density BM are 390mT; Remanent magnetism Br is 120mT; Initial permeability is 2500.
The design parameter of transformer, promptly first no-load voltage ratio is (40-80): 1; The elementary stranded use of insulated copper wire with diameter 0.3-0.6mm, secondary cathode copper copper strips with thickness 0.3-0.6mm.Insulating materials is that the thick 0.05-0.1mm of being mylar, magnetic core slit are 0.2-0.8mm.Power output is between 10-40KW, and during use, transformer combination unit number can be between 1-4.
As shown in Figure 2: the 20th, E type magnetic core, the 42nd, insulating paper, the 21st, the secondary copper strips of ground floor, the 32nd, insulating paper, the 22nd, the secondary copper strips of the second layer, the 33rd, insulating paper, 23 ground floors are elementary multiply copper cash, the 34th, and insulating paper, 24 is tri-layer level copper strips, the 35th, and insulating paper, 25 is the 4th hierarchical level copper strips; The 36th, insulating paper, the 26th, the secondary copper strips of layer 5, the 37th, insulating paper, the 27th, the secondary copper strips of the second layer, the 38th, insulating paper, the 28th, the elementary multiply copper cash of the second layer, the 39th, insulating paper, 28 is tri-layer level copper strips, the 40th, insulating paper, 29 is the 8th hierarchical level copper strips, the 41st, insulating paper.
Wherein, first and second layer is secondary, and the 3rd layer elementary, and fourth, fifth, six, seven layer is secondary, and the 8th layer is elementary; Nine, ten layers is secondary.
Manufacture craft is as follows: elementary segmentation and secondary alternately coiling, and the flow direction of electric current is opposite between the adjacent two layers; Secondary is a circle layering coiling.Elementaryly be clipped in secondary medium line system, the primary and secondary arrangement of conductors is even.Two sections coilings of fraction just separate with insulating paper in the middle of two hierarchical level earlier, again around half is elementary (will be remaining half just do not cut off be put into the there treat nextly to use when elementary) again, and then around four hierarchical level one decks elementary and two hierarchical level.Elementary two-layer being clipped between eight hierarchical level.The material and the structure of present embodiment high frequency transformer have reduced leakage inductance, reduced requirement to IGBT stress, not only can reduce volume, the reduction copper path loss consumption of transformer, be convenient to the derivation of secondary heat, help bigger electric current of high frequency transformer and mash welder output and higher power, improve welding efficiency.Simultaneously, guaranteed the uniformity of transformer parameter, can many transformers are effectively in parallel, further increase the power output of mash welder
The centre tapped mode of connection of transformer adopting, the concrete coiling mode of connection is seen Fig. 3, Fig. 4:
1,5,9,13 is connected to secondary C; 4,8,12,16 be connected to secondary tail E; 2,3,6,7,10,11,14,15 link and be a secondary centre D; 18,19 be connected to the primary center head, elementary head is A, and tail is B;
In secondary, 2 link to each other with 3; 6 link to each other with 7; 10 link to each other with 11; 14 link to each other with 15.Then four groups of secondary centre taps are connected together to finally being the center head D of full-wave rectification.This connected mode, the current opposite in direction of secondary adjacent layer.
End of the same name top is 1,5,9,13,17 (A, C); End end of the same name is 4,8,12,16,20. (B, E); Centre cap D by 2,6,10,14,18 (with E and B be end of the same name) and 3,7,11,15,19 (with C and A be end of the same name) form.
Lead-in wire mode and outward appearance are seen Fig. 5, and the pin of secondary coil and the thin copper belt of secondary coil are integrative-structures, are folded into the plane of transformer axis normal after drawing from each secondary wire ring layer and are convenient to fix with water-cooling plate and commutation diode.
The fixed form of transformer pin: eight secondary centre tapped pin D are separately fixed on the water-cooling plate; Eight output pin C and E are fixed on the commutation diode.Can take away the heat that produces on the transformer secondary output lead to heat by diode and water-cooling aluminium sheet like this, improve power output and arcing time factor according to this.
The principle of the utility model high-frequency invert direct-current point-welding device embodiment circuit as shown in Figure 6.Rectified three-phase circuit is made up of L1-1, L1-2, L1-3, C1, C2, C3, D1, C4, C5, C6, R1 and SRC1; Inverter circuit is made up of M1, M2, M3, M4, R3, R4, R5, R6, D3, D4, D5, D6 and four M57962L driver modules; Dsp controller is that American TI Company is produced (TMS320F2812) 32 bit DSP microprocessors; High-frequency rectification is considered wave circuit and is made up of D7, D8, D9, D10, C9, C10, R11, R12 and L2.
Three-phase electricity utilizes input inductance L1-1, L1-2, L1-3 and capacitor C 1, devices such as C2, C3 to absorb the due to voltage spikes that suppresses on the three-phase alternating current bus through the electromagnetic compatibility circuit, reduces the electromagnetic interference of EMI.Through the direct current of three phase rectifier by being connected on the soft start in the bus bar circuit resistance R 1 and the control of controllable silicon SRC1 at soft starting circuit under at first filter capacitor C4, C5, C6 are charged to busbar voltage after, but open soft start control silicon SRC1 again and make the major loop energising, formation can be carried out the DC bus-bar voltage of inversion, reaches the purpose of soft start.Can reduce interference like this, reduce impact electric capacity, IGBT to electrical network.Utilize between transformer B1, capacitor C 4, C5, the C6 process to carry out the power factor that energy exchange improves complete machine, the purpose that reduces the wastage at switch.Dc source is finished the contrary transforming process of high frequency by turn-on and turn-off at A and 2 of B respectively through bridge circuit switch M1, M4 and M2, M3 under the driving of four M57962L driving chips.Then through high frequency transformer B1 isolation, step-down; Rectifying tube (D7, D8, D9, D10) rectification; High-power low-voltage, high-current is finally exported in inductance (L2) filtering.Electric current is up to 6000A-12000A, and power output is up to 80KW.
Major loop high frequency transformer B1 is that the high frequency transformer by two 25--35KW is formed in parallel, and has less leakage inductance and uniformity electric parameter, the primary and secondary parallel way that adopted respectively.The condition that the high frequency voltage modulator material is selected be initial magnetic permeability 2500, saturation flux density is that 390mT/100 ℃, remanent magnetism are that 120mT, coercivity are that 10A/M, transformer primary and secondary no-load voltage ratio are 40-80:1, the magnetic core gap is 0.2-0.8mm.The inductance deviation should be less than 1%, the leakage inductance deviation should be less than 5%.Also utilized eight pins of transformer secondary output copper strips to receive respectively on the water-cooling aluminium sheet of front and back bridge simultaneously, by secondary copper strips pin the heat transferred heat-dissipating aluminium plate that transformer produced is taken away the heat of transformer by recirculated water, so promptly solve the volume that the heat dissipation problem of sending out transformer has reduced transformer again, improved the electric property of transformer.The transformer outline drawing is seen Fig. 5
Because the appropriate and smaller transformer leakage inductance that the inverter circuit parameter that devices such as IGBT, transformer, output inductor are formed cooperates has reduced the requirement of IBGT back-pressure, make the output current of each transformer can both reach maximum.Suitable output inductor has limited maximum output current, has reduced the stress of IGBT electric current, thereby has improved the reliability and stability of major loop.Simultaneously since main transformer have the supper-fast characteristic of less leakage inductance and device make IGBT when turning on and off source electrode with drain between voltage very little, basically accomplished that no-voltage turns on and off, thereby reduced stress requirement, reduced switching loss switching tube.
Current rectifying and wave filtering circuit carries out the all-wave filtering high-frequency rectifier by Schottky diode D7, D8, D9, D10 and inductance L 2, because tube voltage drop and loop resistance are little, and the rectification efficiency height that makes.C9, R11; C10, R12 are used for reducing transformer to reduce the requirement of the voltage stress of switching tube and high-frequency rectification pipe at the switch moment letter high pressure spike that produces with this, improve the reliability and stability of complete machine.
Dsp controller adopts the TMS320F2812 chip, and four road PMW signals by DSP drive bridge circuit IGBT after four M57962L amplify, then through transformation, rectification, the filtering of transformer, the output welding current.Complete machine has two current inner loop and two outer shrouds, one of them electric current outer shroud and an outer voltage.Its effect is: the 4th current loop I1 utilizes the DC current Hall element that the electric current of dc bus is sampled, then through the processing of the digital PID of DSP inside, the major loop bus current is carried out Current Control, the rectifier bridge and the IGBT components from being damaged that prevent that bus current is excessive and cause are current inner loop; The 3rd current loop utilizes current transformer B2 to the monitoring of sampling of the elementary operating current of high frequency transformer and instant value, then through the processing of the digital PID of DSP inside, working condition to major loop is monitored, the electric current that is used for preventing IGBT is excessive, transformer bias and too fast electric current rate of change and the components from being damaged that causes is a current inner loop of response fast; First current loop is to utilize current transformer or current divider R0 to the monitoring of sampling of the output current of current rectifying and wave filtering circuit, then through the processing of the digital PI of DSP inside, welding current is carried out constant current control, is the electric current outer shroud of a PI high-precision current control; The second voltage loop U1 utilizes voltage hall sensor to the monitoring of sampling of the output voltage of current rectifying and wave filtering circuit, through the processing of the digital PI of DSP inside weldingvoltage is carried out constant voltage control then, is the outer voltage of a PI high-accuracy voltage control.Finish by these four feedback control loops on the whole DSP inside pulse width signal is controlled, thereby reach the purpose of constant current, constant voltage and the control of permanent power of complete machine, also be moment control, make the complete machine working stability reliable output current, voltage and power signal.
M57962L is a quick isolated drive circuit, has overprotection, soft start and alarm function, also has negative pressure output when IGBT turn-offs, and has improved the antijamming capability of IGBT.
On front and back bridge heat sink and transformer, be provided with temperature sensor, can monitor the temperature of IGBT and Schottky diode and transformer, and it is monitored and overheating protection circuit by DSP.
In gas circuit, water route, be provided with pressure sensor, can monitor the hydraulic pressure in water route by DSP, the air pressure of gas circuit, and it is shown and safeguard protection.
In dc bus, be provided with the observation circuit of DC voltage, control supply voltage, can monitor and alarm by DSP.
The utility model circuit structure compactness, rationally distributed, well solved the heat dissipation problem of IGBT, Schottky diode and high frequency transformer.Make power output reach maximum, carry temporary rate during work up to 30%.
The control of DSP sampled signal is to be based upon on the Mathematical Modeling basis of PID, by software IGBT driving signal is controlled.Reach the control of constant current, constant voltage and permanent power to major loop by the control of PID signal.DSP finishes the welding process of single spot welding and three pulses welding by the weldering control program.
The utility model man-machine interface has adopted the very color touch-screen of LCD, forms by LCD demonstration and inputting interface, in/menu in English, flexible and convenient operation, elegant in appearance.