KR20010103345A - Load simulation apparatus of electric arc welding machine - Google Patents

Abstract

The present invention provides a load simulation apparatus for an electric arc welder capable of analyzing the output characteristics of the welder by applying a load similar to the electrical load during welding to the welder and collecting the output variables of the welder reproducibly.

The present invention is connected to the output side of the electric arc welding machine operated by a commercial AC power supply has a function as an electrical load during welding for the electric arc welding machine, the electric arc welding machine for testing the output characteristics of the electric arc welding machine CLAIMS 1. A load simulation apparatus, comprising: shorting means connected to an output end of an electric arc welder for artificially shorting or arcing an output of an electric arc welder; Boosting means for boosting the DC output voltage of the short circuit means at a predetermined ratio when the output of the electric arc welder is in an arc state; Power regeneration means for converting the DC output voltage of the boosting means into a sine wave voltage and feeding it back to the commercial AC power supply side of the electric arc welding machine; The electric arc welding machine and signal measurement and analysis means for collecting the predetermined data desired by the user from each means, analyzing and processing the collected data, and outputting the data as the user can check, so that the power regeneration function is provided, As a result, it is possible to measure and analyze various data indicative of the output characteristics thereof, thereby enabling accurate performance evaluation of the welding machine.

Description

LOAD SIMULATION APPARATUS OF ELECTRIC ARC WELDING MACHINE

The present invention relates to a load simulation apparatus for an electric arc welder, and in particular, an electric load capable of analyzing the output characteristics of the welder by applying a load similar to the electrical load during welding to the welder and collecting the output characteristics of the welder reproducibly. A load simulation apparatus for an arc welder.

Electric arc welding machines are widely used in the construction and construction of transportation machinery, shipbuilding, automobiles, industrial machinery, chemical and power generation facilities, steel structures, such as construction and bridges, and mechanical elements.

The technical requirements for electric arc welders in these industrial sites are safety as electrical equipment and excellent welding performance.

The temperature test, one of the safety evaluation items, applies the load during welding to an electrical static load (e.g., 60% rated use, 29V rated voltage, 300A rated current, and a load of 29V-300A for 6 minutes. This is a test to evaluate whether the temperature of the welder component rises above the specified value, insulation, and breakdown voltage.

In the temperature test, a variable resistor called a load bank, as shown in FIG. 1, is used. Usually, the rated voltage and the rated current are adjusted by cooperatively adjusting the resistance selection switch and the welding machine current and voltage switch. In the temperature test or the rated load test, the electric power flowing through the welder is consumed by the resistance heat generation. Therefore, a device for cooling the resistance heat generation is required. In addition, the user has to bear the electric charge for the heat generation.

On the other hand, the welding performance of the welding machine has been evaluated by the welding company so far without using a measuring instrument or an analyzer. That is, the welder has actually sensed the welding performance of the welder while actually arcing and welding. Evaluation items included arc maneuverability, arcing noise, spatter generation amount, appearance of welded part and arc state felt by welder's hand. These evaluation items are virtually difficult to quantitatively or objectively assess and are evaluated by the welder's subjective judgment. In addition, the welding performance of the welder can be evaluated differently by the characteristics of the electrode or wire, the protective gas, the welding habit of the welder (eg, arc length or torch angle), etc., which actually affects the arc safety because the arc is actually generated.

The welding performance of the welding machine evaluated by the welder by direct welding is not reproducible from the viewpoint of the dynamic waveform. In other words, even when the same welder uses the same material for welding, the waveforms of the welding voltage and current (particularly, the short-circuit waveform and the volumetric flow) may be different, and thus, the performance test is not reproducible. The welder's response to instantaneous short-circuit loads or the welder's output characteristics against arc length changes, even when the welder performs direct welding, are difficult to test based on the welder's skill due to the lack of fast load speed or precise maintenance of the arc length. There was a downside.

The present invention has been made in view of this point, and the present invention provides an apparatus for simulating the load of an electric arc welder, which can test the output characteristics of the electric arc welder by switching the power load of the electric arc welder at a necessary period. have.

Another object of the present invention is to provide a load simulation apparatus for an electric arc welder, which can reduce power usage fees by regenerating power flowing in the welder and feeding it back to the power supply side of the electric arc welder.

It is still another object of the present invention to provide a load simulation apparatus for an electric arc welder capable of evaluating a welder's performance by reproducibly collecting and analyzing output characteristics of a welder for dynamically changing welding loads.

1 is a schematic configuration diagram of a general electric arc welding machine

2 is a block diagram of a load simulation apparatus for an electric arc welding machine according to the present invention.

3 is a detailed configuration diagram of a short circuit of FIG.

4 is a detailed configuration diagram of the booster of FIG. 2.

5 is a detailed configuration diagram of the power regeneration unit of FIG. 2.

<Description of the symbols for the main parts of the drawings>

10: electric arc welding machine 20: time switch

30: short circuit part 40: boosting part

50: power regeneration unit 60: signal measurement and analysis unit

31,41,54: control unit 51: converter

52: coupling 53: transformer

55: phase detection unit

The load simulation apparatus of the electric arc welder of the present invention for achieving the above object is connected to the output side of the electric arc welder operated by a commercial AC power supply, and has a function as an electrical load when welding the electric arc welder. CLAIMS 1. A load simulation apparatus for an electric arc welder for testing output characteristics of the electric arc welder, comprising: shorting means connected to an output end of the electric arc welder for artificially shorting or arcing an output of the electric arc welder; Boosting means for boosting the DC output voltage of the short circuit means by a predetermined ratio when the output of the electric arc welder is in an arc state; Power regeneration means for converting the DC output voltage of the boosting means into a sine wave voltage and feeding it back to the commercial AC power supply side of the electric arc welding machine; And a signal measuring and analyzing means for collecting the predetermined data desired by the user from the electric arc welding machine and each means, analyzing and processing the collected data, and outputting the data as user-identifiable data.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

2 is a block diagram of the load simulation apparatus of the electric arc welding machine according to the present invention. The short circuit section 30, the boosting section 40, the power regeneration section 50, the signal measuring and analyzing section 60 are shown in FIG. ), And further includes a time switch unit 20 for operating the load when applying a static load to the electric arc welder 10.

The short circuit 30 is connected to the output terminal of the electric arc welder 10 through the time switch 20 to simulate the output of the electric arc welder 10 in an artificial short or arc state. The detailed configuration diagram is shown in FIG.

As shown, a base end of the switching transistor TR31 is connected to the control unit 31 for outputting a switching control signal by an internal program, and the transistor TR31 is a + power output end of the electric arc welder 10. The collector stage is connected in parallel to the line resistance R31 connected in series to the side, and the emitter stage is connected in parallel to the negative power supply output side of the electric arc welding machine 10 to the switching control signal from the controller 31. It is then turned on or off to make the output of the electric arc welder 10 short or arced. In addition, an anode terminal of the reverse current prevention diode D31 is connected in parallel to a collector terminal of the transistor TR31, and an electric arc in parallel to the cathode terminal of the diode D31 and the emitter terminal of the transistor TR31, respectively. The condenser C31 for filtering the arc current of the welder 10 is connected and comprised.

4 is a detailed configuration diagram of the booster 40 for boosting the DC output voltage of the short circuit 30 by a predetermined ratio when the output of the electric arc welder 10 is in an arc state. A gate terminal of the switching transistor TR41 is connected to the control unit 41 that outputs a corresponding switching control signal according to a boost ratio set by a resistor, and the collector terminal of the transistor TR41 has a function of storing and emitting energy. Is connected in parallel to the + power output terminal of the short circuit section 30 via a coil (L41) having, and the emitter stage is connected in parallel to the -power output terminal of the short circuit section 30, the turn-on or according to the switching control signal The power is turned off so that the pressure corresponding to the preset boost ratio is achieved. The reverse current preventing diode D41 is connected in parallel with the collector terminal of the transistor TR41, and the reverse current preventing diode D42 is connected to the collector terminal and the emitter terminal of the transistor TR41 in parallel.

FIG. 5 shows a detailed configuration diagram of the power regenerative unit 50 which converts the DC output voltage of the booster unit 40 into a sine wave voltage and feeds it back to the commercial AC power supply side of the electric arc welding machine 10. The converter 51 converts the DC output voltage of the booster 40 into a three-phase sine wave voltage in accordance with a control signal of the converter 51 and converts the output of the converter 51 into a commercial AC power supply of the electric arc welder 10. At the same time, the transformer 53 for feeding back to the commercial AC power supply side of the electric arc welding machine 10 by boosting the AC power level at the same time as the commercial AC power source is connected, and the converter 51 and the transformer 53 are coupled parts formed of coils ( 52).

And a controller 54 for outputting a PWM modulation control signal to the converter 51 such that the voltage waveform and the current waveform of the output waveform of the transformer 53 have the same phase, and the controller 54 has an electric arc. The phase detector 55 is connected to detect the phase of the commercial AC power supply of the welding machine 10 so that the control unit 54 can output an appropriate PWM modulation control signal.

Here, the converter 51 is a PWM type voltage converter composed of transistors TR51-TR56 as switching elements, and the transformer 53 is a three-phase transformer. In addition, the phase detector 55 is composed of three small transformers (not shown), a resistance and a zero crossing detection circuit, and reference numeral C51 denotes a smoothing capacitor.

In addition, although not shown, the control unit 51 includes a hall current transformer (Hall CT) for measuring current flowing through each coil of the coupling unit 52, and a PT (for detecting DC voltage and overcurrent of the converter 51). Potential Transformer) and a condenser may be provided in the periphery, and a protection circuit for protecting the power regenerative unit 50 from overcurrent and phase short circuit may be provided in the periphery thereof.

The control unit 31, 41, 51 may be configured as a microprocessor.

Meanwhile, the signal measuring and analyzing unit 60 collects and collects predetermined data (eg, welding current, welding voltage, welding speed, etc.) desired by the user from the electric arc welder 10 or each unit 30-50. It is a part that analyzes and processes the collected data and outputs it as user-identifiable data. It has an A / D converter that converts the collected data into a digital signal, and consists of a PC equipped with Labview software.

The simulation apparatus of the present invention configured as described above is connected to the output side of the electric arc welder instead of a welding torch or gun to function as an electrical load during welding, and the electrical load is short-circuited to represent a state of displacement. (Short Circuit Transfer), Volume Transfer (Globular Transfer), Spray Transfer (Spray Transfer), and Pulse Transfer (PulseTransfer). These electrical loads can be realized by on / off switching from several milliseconds to hundreds of ms or by continuous on (eg spray transition) switching.

In the present invention, when the transistor TR31 of the short circuit section 30 is turned on, a short circuit condition during welding is performed, and a short circuit current flows through the electric arc welder 10. In addition, when the transistor TR31 of the short circuit section 30 is turned off, it indicates an arc state during welding. At this time, an arc current flows through the electric arc welder 10, and the arc current is generated by the booster 40 and the power regeneration. The unit 50 is returned to the commercial AC power supply side of the electric arc welding machine 10.

In this case, the transistor TR31 is turned on or turned off according to the switching control signal from the control unit 31. The control unit 31 outputs the corresponding switching control signal by an internal timer and a program, and the transistor TR31 is turned on. The on or turn off period is variable.

For example, the on time can be from 0.1ms to 100ms, the off time can be from 1ms to 1000ms, and the repetition of short circuits and the repetition of several short circuit patterns (groups of different paragraph cycles) can also be performed by the program.

In addition, the setting of the short time can be divided into a single paragraph display and a paragraph routine as shown in [Table 1] and [Table 2] below.

Table 1

turn One 2 3 4 5 6 7 8 9 10 Short time (ms) 0.1 0.2 0.4 0.6 1.0 2.0 3.0 5.0 10.0 20.0 Short circuit off (ms) 100 100 100 100 100 100 100 100 100 100

[Table 2]

turn One 2 3 4 5 6 7 8 9 10 Short time (ms) 3 4 One 5 2 4 3 4 4 5 Short circuit off (ms) 12 20 8 30 10 25 10 10 15 12

On the other hand, when welding using most of the MIG / MAG welding machine, the output voltage of the welding machine is 13 ~ 40V level, the welding machine output current is 70 ~ 350A level.

When the simulation apparatus of the present invention is connected to the output side of the electric arc welder 10, the current representing the arc current is passed through the short circuit 30 and the booster 40 to the converter 51 of the power regeneration unit 50. Determination of the step-up ratio of the boosting unit 40 determines the DC voltage of the converter 51, and accordingly the circuit element is selected, the transformer ratio and PWM of the transformer 53 to be used on the AC side. The adjustment range of the modulation rate is determined. The selection resources of these devices or the variables that flow or run through them are interdependent.

Here, the booster 40 may perform one-step boost or two-step boost, and the principle of the boost is expressed by a formula. At this time, the power supply side voltage is a commercial voltage such as 220V or 440V, while the DC side voltage (E _d ) must be maintained at the voltage expressed by the following equation.

V _ac = E _d

That is, when the power supply voltage is 220V sine wave AC, the DC side voltage should be maintained at about 135V level.

Therefore, when the welding machine output voltage is 28V, a DC voltage increase of about 10.7 times is required.

In order to satisfy this demand, a booster circuit called a chopper boosting method is used for the boosting unit 40. In the boosting unit 40, the turn-on period T _on and the turn-off period ( T _off ), the voltage E _omega on the output side of the short circuit section 30 and the voltage E _C on the power regeneration section 50 side hold the following equation.

T _on × E _ω = T _off × (E _C -E _ω )

According to this relation, the step-up ratio E _C / E _ω is determined by the ratio of (1 + T _on / T _off ).

Accordingly, in the present invention, the control unit 41 controls T _on and T _off , and the setting of T _on and T _off is directly set by a variable resistor (not shown) connected to the control unit 41 or the control unit 41. It is set automatically by the program in).

In addition, the DC output voltage of the booster 40 smoothed by the capacitor C51 in the power regenerative unit 50 is input to the converter 51 and converted into a sine wave voltage. That is, the converter 51 operates the transistors TR51-TR56 according to the PWM modulation control signal input from the controller 54 to output the DC output voltage of the booster 40 as a three-phase sine wave voltage. Accordingly, since the DC power is modulated into the same waveform as that of the commercial AC power supply, the power can be regenerated by the power supply. The output of the converter 51 is supplied through the three-phase transformer 53 via the combiner 52. It is transformed into the same size as the waveform and fed back to the commercial AC power supply. Here, the transformer 53 also insulates the output of the coupler 52 from the commercial AC power supply.

In addition, the output of the transformer 53 should be made of the same phase (power factor is 1) of the voltage waveform and the current waveform, which is possible according to the PWM modulation control signal output from the controller 54, the controller 54 ) Outputs the corresponding PWM modulation control signal according to the phase of the power source detected by the phase detection unit 55. Here, the PWM modulation control signal outputs 42 pulses per cycle of the AC power supply, so that a waveform very close to the sine wave can be output from the converter 51.

The control unit 54 maintains the vector relationship between the DC side voltage, the power side voltage, and the coil of the combiner 52 during PWM modulation, and modulates arithmetic rate control and proportional integral (PI) control so that the modulation waveform approximates a sine wave. It has features for around it.

The signal measurement and analysis unit 60 collects the desired data from the electric arc welder 10 or the respective units 30-50, converts the collected data into a digital signal using an A / D converter, and then reads the lab view. (Labview) The software is processed and analyzed to obtain the desired result and display it on the monitor.

The A / D converter measures analog signals that change according to voltage, current, and other times during welding or welding simulation at high speed to 8 channels, and converts them into digital signals. The measurement speed is up to 250kbps.

The LabVIEW software can measure and analyze various signals during welding by utilizing data acquisition, interface, data processing, and other mathematical library functions. Typical examples include filter function, VI curve generation, short count coefficient, and Fourier ( Fourier) transform, Z transform, and so on.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

As described above, the present invention eliminates the need for a cooling device for cooling conventional resistance heat by replacing a load device made of an electric resistor of a conventional electric arc welder, and has a power regeneration function. Will be.

In addition, according to the present invention, it is possible to apply an artificial load to the welding machine and to measure and analyze various data indicative of the output characteristics thereof, thereby enabling accurate performance evaluation of the welding machine.

Claims (26)

A load simulation device for an electric arc welder connected to an output side of an electric arc welder operated by a commercial AC power supply, having a function as an electrical load during welding for the electric arc welder, and for testing output characteristics of the electric arc welder. To Short-circuit means connected to an output end of said electric arc welder for artificially shorting or arcing the output of said electric arc welder; Boosting means for boosting the DC output voltage of the short circuit means by a predetermined ratio when the output of the electric arc welder is in an arc state; And a power regenerative means for converting the DC output voltage of the boosting means into a sine wave voltage and feeding it back to the commercial AC power supply side of the electric arc welder. The method of claim 1, wherein the short circuit means Switching means for simulating the output of the electric arc welder in a short or arc state in accordance with a switching control signal from the outside; And a control means for outputting a switching control signal to the switching means by an internal program. The method of claim 2, wherein the switching means The collector stage is connected in parallel to the line resistance connected in series to the + power output terminal side of the electric arc welder, the gate stage is connected to the control means, and the emitter stage is parallel to the −power output terminal side of the electric arc welder. And a switching transistor which is connected to and turned on or off in accordance with a switching control signal output from the control means. 4. The capacitor of claim 3, wherein an anode terminal of the reverse current prevention diode is connected in parallel to the collector terminal of the transistor, and an arc current of the electric arc welder is filtered in parallel to the cathode terminal of the diode and the emitter terminal of the transistor. Load simulation apparatus for an electric arc welder, characterized in that connected. According to claim 1, wherein said boosting means Switching means for turning on / off the output current of the short circuit means in accordance with a switching control signal from the outside; And a control means for outputting a corresponding switching control signal to the switching means in accordance with a preset step-up ratio. The method of claim 5, wherein the switching means The collector stage is connected in parallel to a coil connected in series with the + power output terminal of the short circuit means, the gate end is connected to the control means, and the anode stage is connected in parallel to the -power output output terminal of the short circuit means, so that the switching Load simulation device of an electric arc welder, characterized in that consisting of a switching transistor that is turned on or off in accordance with a control signal. 6. An apparatus as claimed in claim 5, wherein the step-up ratio of the control means is set by an internal program of the control means or by a variable resistor connected to the control means. The method of claim 1, wherein the power regeneration means Conversion means connected to an output terminal of the boosting means and converting the DC output voltage of the boosting means into a sine wave voltage according to an external control signal; Transformer transforming means for isolating the output of said converting means from the commercial AC power source of said electric arc welder and simultaneously boosting it to the level of commercial AC power source and feeding it back to the commercial AC power source side of said electric arc welder; And a control means for outputting a PWM modulation control signal to the conversion means. The load simulation apparatus of an electric arc welder according to claim 8, wherein the conversion means is a PWM type voltage converter comprising a plurality of switching elements for converting the DC output voltage of the boosting means into a three-phase sine wave voltage. . 9. The load simulation apparatus of an electric arc welder according to claim 8, wherein the control means outputs a PWM modulation control signal such that the voltage waveform and the current waveform of the output waveform of the transformer have the same phase. 9. The load of the electric arc welder of claim 8, further comprising a phase detection means for detecting a phase of a commercial AC power supply of the electric arc welder and outputting an appropriate PWM modulation control signal from the control means. Simulation device. 9. The apparatus for simulating load of an electric arc welder according to claim 8, further comprising coupling means for coupling the conversion means and the transformer means. 13. The apparatus for simulating load of an electric arc welder according to claim 12, wherein the coupling means is a coil. The electric arc welding machine according to claim 1, further comprising a time switch means for operating the output load of the electric arc welder between the output end of the electric arc welder and the short circuit means when a static load is applied to the electric arc welder. Load simulation device of arc welder. The method of claim 1, further comprising signal measuring and analyzing means for collecting predetermined data desired by the user from the electric arc welding machine and each means, analyzing and processing the collected data, and outputting the data as user identifiable data. Load simulation device for electric arc welders. 16. The load simulation apparatus of claim 15, wherein the signal measuring and analyzing means is a PC equipped with Labview software. A load simulation device for an electric arc welder connected to an output side of an electric arc welder operated by a commercial AC power supply, having a function as an electrical load during welding for the electric arc welder, and for testing output characteristics of the electric arc welder. To Short-circuit means connected to an output end of said electric arc welder for artificially shorting or arcing the output of said electric arc welder; Boosting means for boosting the DC output voltage of the short circuit means by a predetermined ratio when the output of the electric arc welder is in an arc state; Power regeneration means for converting the DC output voltage of the boosting means into a sine wave voltage and feeding it back to the commercial AC power supply side of the electric arc welder; The electric arc welder and the load of the electric arc welder comprising a signal measuring and analyzing means for collecting the predetermined data desired by the user from each means to analyze and process the collected data to the user confirmable data Simulation device. 18. The apparatus of claim 17, wherein the short circuit means Switching means for simulating the output of the electric arc welder in a short or arc state in accordance with a switching control signal from the outside; And a control means for outputting a switching control signal to the switching means by an internal program. 18. The method of claim 17, wherein the boosting means Switching means for turning on / off the output current of the short circuit means in accordance with a switching control signal from the outside; And a control means for outputting a corresponding switching control signal to the switching means in accordance with a preset step-up ratio. 18. The method of claim 17, wherein the power regeneration means Conversion means connected to an output terminal of the boosting means and converting the DC output voltage of the boosting means into a sine wave voltage according to an external control signal; Transformer transforming means for isolating the output of said converting means from the commercial AC power source of said electric arc welder and simultaneously boosting it to the level of commercial AC power source and feeding it back to the commercial AC power source side of said electric arc welder; And a control means for outputting a PWM modulation control signal to the conversion means. 21. The load simulation apparatus for an electric arc welder according to claim 20, wherein the conversion means is a PWM type voltage converter comprising a plurality of switching elements for converting the DC output voltage of the boosting means into a three-phase sine wave voltage. . 21. The load simulation apparatus according to claim 20, wherein the control means outputs a PWM modulation control signal so that the voltage waveform and the current waveform of the output waveform of the transformer have the same phase. 21. The load of the electric arc welder of claim 20, further comprising a phase detecting means for detecting a phase of an alternating current power supply of the electric arc welder and outputting an appropriate PWM modulation control signal from the control means. Simulation device. 21. The apparatus for simulating load of an electric arc welder according to claim 20, further comprising coupling means for coupling the converting means and the transformer means. 18. An electric machine according to claim 17, further comprising a time switch means for operating the output load of the electric arc welder between the output end of the electric arc welder and the shorting means when a static load is applied to the electric arc welder. Load simulation device of arc welder. 18. The apparatus for simulating load of an electric arc welder according to claim 17, wherein the signal measuring and analyzing means is a PC equipped with Labview software.