JP2009225569A - Power supply for arc discharge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply for arc discharge, which can stabilize arc discharge and also can prevent arc-extinguishing arc discharge, even for small arc current. <P>SOLUTION: A control circuit 10 is provided with a voltage positive feedback control circuit 20 and further with an adder 15. The voltage positive feedback control circuit 20 comprises an arc voltage detecting section 16, which detects arc voltage to be applied to an arc discharge load and outputs an arc voltage detected value 23, a filter 17, which removes noise components and DC components in the arc voltage detected value 23, and a regulator 18 which amplifies the arc voltage detected value 23, having the noise components and DC components removed therefrom and outputs the value to the adder 15 as an arc voltage control amount 24. The adder 15 adds the arc voltage control amount 24 to the arc current control amount 22, to make it a control amount 19. When the control amount 19 increases, the DC/AC conversion means operates so that the semiconductor switch thereof makes the arc current increased. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an arc discharge power supply device.

  FIG. 7 is a block diagram of a conventional arc discharge power supply apparatus 101. In the arc discharge power supply device 101, the AC voltage output from the AC power supply 102 is rectified by the rectifier 103 to obtain a DC voltage. The DC current output from the rectifier 103 is input to the DC / AC converter 104. The DC / AC converter 104 includes a semiconductor switch, and the semiconductor switch performs switching, thereby converting a DC voltage into an AC voltage.

  The AC voltage converted by the DC / AC converter 104 is input to the primary side of the transformer 105, and the AC voltage stepped down from the secondary side is output. The AC voltage output from the secondary side of the transformer 105 is input to the rectifier circuit and smoothing circuit 106, and is rectified and smoothed to become a DC voltage. When the DC voltage output from the rectifier circuit and smoothing circuit 106 is applied to the arc discharge load 107, electric power is supplied to the arc discharge load 107, and arc discharge is performed.

  In such an arc discharge power supply device 101, an arc current, that is, a current flowing through the arc discharge load 107 is detected and a difference from a target arc current value is obtained to obtain an arc current deviation. This arc current deviation is amplified by inputting it to a regulator, and feedback control is used as a control amount for controlling the arc current. In the prior art, in order to stabilize arc discharge by the above feedback control and prevent arc extinction, a system for performing control for obtaining a correction amount from the detected value of arc current has been incorporated into the control system.

  In Patent Document 1, a control amount is obtained by feedback control in which a load current is detected and added to a target value. The control output is obtained by further amplifying the value obtained by the addition by the regulator.

In Patent Document 2, a control amount is obtained by feedback control that adds a detected load voltage and a target value, a correction amount obtained by differentiating and amplifying the load current is added to the control amount, and the obtained value is adjusted by a regulator. The control output is obtained by further amplifying the signal.
JP-A-8-243743 (published September 24, 1996) Japanese Patent No. 3231649 (Registered on September 14, 2001)

  In the above prior art, the correction amount obtained from the detected value of the arc current is used for stabilizing the arc discharge. When the arc current is sufficiently large, that is, the arc current is about 40 A (100%), it is possible to stabilize the arc discharge, but the low current, that is, the arc current is reduced to 30 A (75%) or less. When arc discharge is performed in such a state, the arc discharge cannot be stabilized, and the arc discharge is extinguished. Therefore, in order to stabilize the arc discharge performed in a state where the arc current is small, control capable of responding at higher speed is required.

  Further, in the configuration of the control system in the above prior art, the control output is obtained by further performing amplification after adding the correction amount by the arc current to the control amount obtained by the feedback control. For this reason, there arises a problem that the influence of the final-stage regulator extends to the correction amount obtained from the load current.

  Furthermore, if the final stage controller includes an integrator to eliminate the steady-state deviation, only the change in the arc current is detected by the differentiator, and the differential action performed when obtaining the correction amount from this change. It is assumed that the problem will be offset.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide arc discharge that can stabilize arc discharge and prevent arc extinguishment even when the arc current is small. It is to provide a power supply device for a vehicle.

  In order to solve the above problems, an arc discharge power supply device of the present invention has a rectifying means for rectifying an AC voltage output from an AC power supply to obtain a DC voltage, and a semiconductor switch, and the semiconductor switch performs switching. And a DC / AC converter for converting the DC voltage output from the rectifier to a second AC voltage, and a transformer for stepping down the second AC voltage converted by the DC / AC converter. , A rectifying / smoothing means that rectifies and smoothes the third AC voltage stepped down by the transformer means to obtain a second DC voltage, and a control means, and the control means rectifies by the rectifying / smoothing means. The smoothed second DC voltage is applied to an arc discharge load that performs arc discharge, detects an arc current flowing through the arc discharge load, and outputs an arc current detection value. Current detecting means, a subtracting means for taking a difference between the detected arc current value and the arc current set value and outputting the difference as an arc current deviation, and amplifying the arc current deviation, and the DC / AC converting means as an arc current control amount Adjusting means for outputting to the arc discharge power supply device, wherein the DC / AC converting means operates so that the semiconductor switch increases the arc current when the amount of control of the arc current increases. Further includes a voltage positive feedback control means and an addition means, wherein the voltage positive feedback control means detects an arc voltage of the arc discharge load and outputs an arc voltage detection value; and the arc A filter for removing the noise component and the DC component of the voltage detection value, and amplifying the arc voltage detection value from which the noise component and the DC component have been removed, Second adjusting means for outputting to the adding means as a voltage control amount, and the adding means adds the arc voltage control amount to the arc current control amount to obtain a control amount, and the DC-AC conversion The means is characterized in that the semiconductor switch operates to increase the arc current when the control amount increases.

  When the arc discharge becomes unstable at the time of arc discharge when the arc current is low, that is, when the arc current is small, the arc voltage increases. Thereafter, the arc current decreases and the arc discharge is extinguished.

  According to the invention, in the control means, the output of the voltage positive feedback control means, that is, the arc voltage control amount increases with the increase of the arc voltage, and the arc current control amount increases as in the case where the arc current control amount increases. The amount of control increases. Accordingly, since the control means operates before the arc current is reduced and the arc discharge is extinguished, it is possible to respond at a higher speed than in the prior art. It is possible to stabilize discharge and prevent arc discharge from being extinguished.

  In the control means, the adjusting means is provided for outputting the arc current control amount, and the second adjusting means is provided for outputting the arc voltage control amount. Conventionally, both the arc current control amount and the arc voltage control amount are generated by amplification of one regulator. Therefore, when trying to amplify the arc current, the arc voltage is also amplified at the same time. Furthermore, it could be set only to an amplification factor (gain) at which neither the arc current nor the arc voltage oscillates.

  On the other hand, the control means can independently determine the gain of the adjusting means and the gain of the second adjusting means, so that the degree of freedom of the gain and the degree of control are increased.

  Further, in order to eliminate the steady deviation of the arc current, an integrating element may be included in the regulator. However, since the integrating element is a delay element, the response becomes slow. Conventionally, since there is only one regulator, if an integral element is included in order to eliminate the steady deviation of the arc current, the response becomes slow.

  On the other hand, the control means only needs to include an integral element in the adjusting means in order to eliminate a steady deviation of the arc current, and it is not necessary to include an integral element in the second adjusting means. Can be prevented.

  In the arc discharge power supply device, the control means further includes a current negative feedback control means and a second subtraction means, and the current negative feedback control means is a direct current of the arc current detection value. A second filter that removes a component; and a third adjusting unit that amplifies the detected arc current value from which the direct current component has been removed and outputs the amplified value to the second subtracting unit as a second arc current control amount. The second subtracting unit may take a difference between the arc current control amount and the second arc current control amount, and output the difference to the adding unit instead of the arc current control amount. .

  When the arc discharge becomes unstable due to disturbance or the like, the arc voltage first increases and then the arc current decreases. Therefore, the response speed of the current negative feedback control means is slower than the voltage positive feedback control means. . Further, the voltage positive feedback control means can respond faster to the transient fluctuation than the current negative feedback control means. However, it is possible to perform control with a higher degree of freedom by coexisting two control means having different response speeds.

  In any one of the above arc discharge power supply devices, the voltage positive feedback control means may further include a limiter for limiting the output of the voltage positive feedback control means to be always zero or more.

  In any one of the arc discharge power supply devices, the arc voltage is constant when the arc discharge is stable. When the arc discharge becomes unstable, the arc voltage is rapidly increased and then repeatedly increased and decreased to extinguish the arc discharge.

  Except when the arc discharge becomes unstable, the arc voltage may decrease when the arc discharge is not performed, for example, when any one of the arc discharge power supply devices is started. Thus, when the arc voltage decreases, it is preferable that the voltage positive feedback control means does not perform control.

  The limiter limits the output of the voltage positive feedback control means so that the output of the voltage positive feedback control means is always greater than or equal to zero. The control means only applies the positive voltage positive feedback when the arc voltage is increased by the limiter. The arc voltage control amount is output from the control means to the adding means.

  In the arc discharge power supply device according to the present invention, as described above, the control means further includes a voltage positive feedback control means and an addition means, and the voltage positive feedback control means is applied to the arc discharge load. An arc voltage detection means for detecting an arc voltage and outputting an arc voltage detection value, a filter for removing a noise component and a DC component of the arc voltage detection value, and the arc voltage detection value from which the noise component and the DC component have been removed And a second adjusting means for outputting to the adding means as an arc voltage control amount, the adding means adding the arc voltage control amount to the arc current control amount as a control amount, The DC / AC converting means operates such that when the control amount increases, the semiconductor switch included in the DC / AC converting means increases the arc current.

  Therefore, even when the arc current is small, it is possible to provide an arc discharge power supply device that can stabilize the arc discharge and prevent the arc discharge from being extinguished.

  An embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a block diagram of an arc discharge power supply device 1 according to an embodiment of the present invention. The arc discharge power supply device 1 includes a rectifier 3, a DC / AC converter 4, a transformer 5, a rectifier circuit and a smoothing circuit 6.

  In the arc discharge power supply device 1, the AC voltage output from the AC power supply 2 is rectified by the rectifier 3 to obtain a DC voltage. The DC current output from the rectifier 3 is input to the DC / AC converter 4. The DC / AC converter 4 includes a semiconductor switch 55 described later, and the semiconductor switch 55 performs switching, thereby converting a DC voltage into an AC voltage.

  The AC voltage converted by the DC / AC converter 4 is input to the primary side of the transformer 5, and the AC voltage stepped down from the secondary side is output. The AC voltage output from the secondary side of the transformer 5 is input to the rectifier circuit and smoothing circuit 6 and is rectified and smoothed to become a DC voltage. When the DC voltage output from the rectifier circuit and the smoothing circuit 6 is applied to the arc discharge load 7, electric power is supplied to the arc discharge load 7 and arc discharge is performed.

  The DC / AC converter 4 includes a control unit 8 and a circuit unit 9. The control unit 8 detects the arc voltage and the arc current, and outputs a control amount to the circuit unit 9 based on these detected values. The arc voltage is a voltage applied to the arc discharge load 7, and the arc current is a current flowing through the arc discharge load 7.

  The circuit unit 9 converts the DC voltage into an AC voltage by controlling on / off of the semiconductor switch 55 included in the circuit unit 9 based on the control amount output from the control unit 8. By controlling the DC / AC converter 4 in this manner, arc discharge can be controlled.

  Below, the circuit structure in the control part 8 of FIG. 1 is demonstrated based on Example 1-Example 3 and FIGS. 2-4. Any of the control circuits 10, 25, and 31 described in the first to third embodiments can be used for the control unit 8.

[Example 1]
FIG. 2 is a circuit diagram of the control circuit 10 according to the first embodiment. The control circuit 10 includes a subtractor 12, an arc current detector 13, a regulator 14, an adder 15, an arc voltage detector 16, a filter 17, and a regulator 18. Further, the arc voltage detector 16, the filter 17 and the regulator 18 constitute a voltage positive feedback control circuit 20.

  In the control circuit 10, first, the arc current in the arc discharge power supply device 1 of FIG. 1, that is, the current flowing through the arc discharge load 7 is detected by the arc current detection unit 13, and the arc current detection unit 13 outputs the arc current detection value 21. To do. Next, the subtracter 12 takes the difference between the arc current set value 11 and the detected arc current value 21 and outputs the difference to the adjuster 14 as an arc current deviation. The adjuster 14 amplifies the arc current deviation and outputs it to the adder 15 as the arc current control amount 22.

  The arc voltage in the arc discharge power supply device 1 of FIG. 1, that is, the voltage applied to the arc discharge load 7 is detected by the arc voltage detection unit 16, and the arc voltage detection unit 16 outputs an arc voltage detection value 23. The arc voltage detection value 23 is input to the regulator 18 via the filter 17. The filter 17 removes a noise component and a direct current component included in the arc voltage detection value 23 and outputs only a change in the arc voltage detection value 23. For example, a high-pass filter having a cutoff frequency of several tens of hertz is used as the filter 17, but a band-pass filter may be used. The regulator 18 amplifies the detected arc voltage value 23 from which the noise component and the direct current component have been removed, and outputs the amplified value to the adder 15 as an arc voltage control amount 24.

  The adder 15 adds the arc voltage control amount 24 to the arc current control amount 22 to obtain a control amount 19. The control amount 19 is output to the circuit unit 9 in FIG. 1 and is used for on / off control of the semiconductor switch 55 included in the circuit unit 9.

  At the time of arc discharge when the arc current is low, that is, when the arc current is small, the arc voltage increases when the arc discharge becomes unstable. Thereafter, the arc current decreases and the arc discharge is extinguished.

  On the other hand, in the control circuit 10, as the arc voltage increases, the output of the voltage positive feedback control circuit 20, that is, the arc voltage control amount 24 also increases, and the control amount 19 becomes the same as when the arc current control amount 22 increases. Will increase. Therefore, since the control circuit 10 operates before the arc current is reduced and the arc discharge is extinguished, it is possible to respond faster than in the past, and even when the arc current is small, the arc discharge Stabilization and arc extinction can be prevented.

  Further, in the control circuit 10, an adjuster 14 is provided for outputting the arc current control amount 22, and an adjuster 18 is provided for outputting the arc voltage control amount 24. Conventionally, both the arc current control amount and the arc voltage control amount are generated by amplification of one regulator. Therefore, when trying to amplify the arc current, the arc voltage is also amplified at the same time. Furthermore, it could be set only to an amplification factor (gain) at which neither the arc current nor the arc voltage oscillates.

  In contrast, the control circuit 10 can independently determine the amplification factor of the regulator 14 and the amplification factor of the regulator 18, so that the degree of freedom of the amplification factor and the degree of freedom of control are increased.

  Further, in order to eliminate the steady deviation of the arc current, an integrating element may be included in the regulator. However, since the integrating element is a delay element, the response becomes slow. Conventionally, a regulator is installed at the final stage of the control calculation. Therefore, if an integral element is included, all controls are delayed and the response is delayed.

  On the other hand, the control circuit 10 only needs to include an integral element in the regulator 14 in order to eliminate the steady-state deviation of the arc current, and it is not necessary to include the integral element in the regulator 18, so that the response becomes slow. It is possible to prevent.

[Example 2]
FIG. 3 shows a circuit diagram of the control circuit 25 according to the second embodiment. The control circuit 25 is obtained by adding a current negative feedback control circuit 26 and a subtracter 30 to the control circuit 10 of the first embodiment.

  The negative current feedback control circuit 26 includes a filter 27 and a regulator 28. The detected arc current value 21 is input to the filter 27, and the DC component of the detected arc current value 21 is removed. The detected arc current value 21 from which the direct current component has been removed is amplified by the regulator 28 and becomes an arc current control amount 29. The subtracter 30 takes the difference between the arc current control amount 22 and the arc current control amount 29 and outputs the difference to the adder 15. In this case, since the adjuster 14 and the adjuster 28 are different adjusters, the amplification factor can be determined independently.

  The current negative feedback control circuit 26 operates only when the arc current changes because the filter passes only a rapid change (high frequency component) of the arc current, and does not operate when the arc current is stable. .

  When the arc discharge becomes unstable due to disturbance or the like, the arc voltage first increases and then the arc current decreases. Therefore, the response speed of the current negative feedback control circuit 26 is slower than that of the voltage positive feedback control circuit 20. . Further, the voltage positive feedback control circuit 20 can respond to the transient fluctuation faster than the current negative feedback control circuit 26. However, it is possible to perform control with a higher degree of freedom by coexisting two control circuits having different response speeds.

Example 3
FIG. 4 is a circuit diagram of the control circuit 31 according to the third embodiment. The control circuit 31 is obtained by adding a limiter 32 to the control circuit 25 of the second embodiment.

  The voltage positive feedback control circuit 33 is obtained by providing a limiter 32 at the output of the regulator 18 in the voltage positive feedback control circuit 20 of FIG.

  In the arc discharge power supply device 1 of FIG. 1, the arc voltage is constant when the arc discharge is stable. When the arc discharge becomes unstable, the arc voltage rapidly increases and then repeatedly increases and decreases to extinguish the arc discharge.

  Except when the arc discharge becomes unstable, the arc voltage may decrease when the arc discharge is not performed, for example, when the arc discharge power supply device is started up. When the arc voltage decreases as described above, it is preferable that the voltage positive feedback control circuit does not perform control.

  The limiter 32 applies a limit so that the arc voltage control amount 34 output from the voltage positive feedback control circuit 33 to the adder 15 is always zero or more. As described above, since the filter 17 removes the noise component and the direct current component included in the arc voltage detection value 23, only the change in the arc voltage is input to the limiter 32. Therefore, the arc voltage control amount 34 is positive only when the arc voltage increases. When the arc voltage is constant, the arc voltage control amount 34 becomes zero. When the arc voltage decreases, the arc voltage control amount 34 is originally negative, but the limiter 32 also sets the arc voltage control amount 34 when the arc voltage decreases to zero.

  As described above, the control circuit 31 according to the third embodiment is obtained by adding the limiter 32 to the control circuit 25 according to the second embodiment. However, the present invention is not limited to this, and the control according to the first embodiment is not limited thereto. A limiter may be added to the circuit 10.

  FIG. 5 is a circuit diagram showing an example of the limiter 32 according to the embodiment of the present invention. In the circuit of FIG. 5, the regulator 18 includes a differential amplifier AMP1, a differential amplifier AMP2, and resistors R1 to R4, and the limiter 32 includes a diode D.

  One end of the resistor R2 is connected to the filter 17, and the other end of the resistor R2 is connected to the cathode of the diode D, one end of the resistor R1, and the inverting input terminal (−) of the differential amplifier AMP1. The non-inverting input terminal (+) of the differential amplifier AMP1 is electrically grounded. The output of the differential amplifier AMP1 is connected to the anode of the diode D, the other end of the resistor R1, and one end of the resistor R3.

  The other end of the resistor R3 is connected to one end of the resistor R4 and the inverting input terminal (−) of the differential amplifier AMP2. The non-inverting input terminal (+) of the differential amplifier AMP2 is electrically grounded. The output of the differential amplifier AMP2 is connected to the other end of the adder 15 and the resistor R4.

  After the arc discharge becomes unstable and the arc voltage rises rapidly, the increase and decrease are repeated. In this case, the change in the arc voltage detection value 23 from which the noise component and the DC component are removed, which is input to the inverting input terminal (−) of the differential amplifier AMP1, becomes positive when the arc voltage increases, and the arc voltage is increased. It becomes negative when falls.

  When the change is positive, the output voltage of the differential amplifier AMP1 is negative, and the arc voltage control amount 34 output from the differential amplifier AMP2 is positive. In this case, the diode D is off.

  When the change is negative, the output voltage of the differential amplifier AMP1 is positive, and the diode D is turned on. Since the output voltage of the differential amplifier AMP1 becomes zero when the diode D is turned on, the arc voltage control amount 34 also becomes zero.

  As described above, the arc voltage control amount 34 output from the differential amplifier AMP2 is always zero or more by the diode D constituting the limiter 32. Therefore, when the arc discharge becomes unstable and the increase / decrease is repeated after the arc voltage suddenly rises, the arc discharge power supply device 1 operates to increase the arc current and prevents the arc discharge from being extinguished.

  Hereinafter, a specific circuit configuration of the arc discharge power supply device 1 of FIG. 1 will be described. FIG. 6 is a circuit diagram showing an example of a power supply device for arc discharge according to the embodiment of the present invention. 6 generally includes a rectifier 3, a DC / AC converter 4, a transformer 5, a rectifier circuit and a smoothing circuit 6, and an arc discharge load 7 is provided in the rectifier circuit and the smoothing circuit 6. It is connected. The arc discharge load 7 includes a wire 37 continuously supplied from the hoop 36 and a base material 38.

  The rectifier 3 has an input rectifier 39 and a smoothing capacitor 40. The transformer 5 includes a transformer 41. The rectifier circuit and smoothing circuit 6 includes an output rectifier 42 and a smoothing reactor 43.

  The DC / AC converter 4 includes a control unit 8 and a circuit unit 9. The control unit 8 includes an arc current detection unit 13, a regulator 14, a filter 17, a differential amplifier 47, resistors 49 to 53, and a voltage source 54. The circuit unit 9 includes an inverter 44.

  The arc current I flowing through the arc discharge load 7 is detected by the arc current detector 13, and the arc current detection value 56 is amplified by the differential amplifier 47. Next, the difference between the arc current setting value 11 by the voltage source 54 and the amplified arc current detection value 21 is taken, and the difference is amplified by the regulator 14 to obtain the arc current control amount 22.

  On the other hand, the detected arc voltage value 23 applied to the arc discharge load 7 is freed from noise components and DC components by the filter 17 and further amplified by the regulator 18 to become an arc voltage control amount 24.

  When the arc current control amount 22 and the arc voltage control amount 24 are input to the inverter 44, the inverter 44 has a semiconductor switch 55 inside, and converts a DC voltage into an AC voltage. By controlling the DC / AC converter 4 in this manner, arc discharge can be controlled.

  Note that the arc discharge power supply device 1 described in the present embodiment can stabilize various arc discharges without being restricted by the type of arc discharge. The arc discharge power supply device 1 can be used for an arc welding machine, for example.

  Since the arc discharge power supply device of the present invention can stabilize arc discharge and prevent arc discharge extinction even when the arc current is small, it is suitable for arc discharge equipment such as arc welders. Can be used.

It is a block diagram of the power supply device for arc discharge which concerns on embodiment of this invention. It is a block diagram of a control circuit concerning an example of the present invention. It is a block diagram of the control circuit which concerns on the other Example of this invention. It is a block diagram of the control circuit which concerns on another Example of this invention. It is a circuit diagram which shows an example of the limiter which concerns on embodiment of this invention. It is a circuit diagram showing an example of a power supply device for arc discharge concerning an embodiment of the invention. It is a block diagram of the conventional power supply device for arc discharge.

Explanation of symbols

1, 35 Arc discharge power supply 2 AC power supply 3 Rectifier (rectifying means)
4 DC / AC converter (DC / AC converter)
5 Transformers (transformation means)
6 Rectifier circuit and smoothing circuit (rectifying and smoothing means)
7 Arc discharge load 8 Control unit 9 Circuit unit 10 Control circuit (control means)
11 Arc current set value 12 Subtractor (subtraction means)
13 Arc current detector (arc current detector)
14 Controller (Adjustment means)
15 Adder (addition means)
16 Arc voltage detector (arc voltage detector)
17, 27 Filter 18 adjuster (second adjusting means)
19 Control amount 20 Voltage positive feedback control circuit (voltage positive feedback control means)
21 Arc current detection value 22 Arc current control amount (arc current control amount)
23 Arc voltage detection value 24, 34 Arc voltage control amount 25, 31 Control circuit 26 Current negative feedback control circuit 28 Controller (third adjusting means)
29 Arc current control amount (second arc current control amount)
30 subtractor (second subtracting means)
32 limiter 33 voltage positive feedback control circuit 36 hoop 37 wire 38 base material 39 input rectifier 40 smoothing capacitor 41 transformer 42 output rectifier 43 smoothing reactor 44 inverter 47, AMP1, AMP2 differential amplifier 49-53, R1-R4 resistance 54 voltage Hara 55 Semiconductor Switch D Diode

Claims (4)

Rectifying means for rectifying an AC voltage output from an AC power source to obtain a DC voltage;
DC / AC conversion means for converting the DC voltage output from the rectifying means into a second AC voltage by having a semiconductor switch and switching the semiconductor switch;
Transforming means for stepping down the second AC voltage converted by the DC / AC converting means;
Rectifying and smoothing means for rectifying and smoothing the third AC voltage stepped down by the transformer means to obtain a second DC voltage;
Control means,
The control means applies the second DC voltage rectified and smoothed by the rectifying and smoothing means to an arc discharge load for arc discharge, detects an arc current flowing through the arc discharge load, and detects an arc current. Arc current detection means for outputting a value;
Subtracting means for taking the difference between the arc current detection value and the arc current set value and outputting the difference as an arc current deviation;
Adjusting means for amplifying the arc current deviation and outputting the arc current control amount to the DC / AC conversion means;
The DC / AC converter means, when the arc current control amount is increased, in the arc discharge power supply device in which the semiconductor switch operates to increase the arc current,
The control means further includes a voltage positive feedback control means and an addition means,
The voltage positive feedback control means detects an arc voltage of the arc discharge load, and outputs an arc voltage detection value; arc voltage detection means;
A filter that removes a noise component and a DC component of the arc voltage detection value;
A second adjusting means for amplifying the detected arc voltage value from which a noise component and a direct current component have been removed and outputting the detected value to the adding means as an arc voltage control amount;
The adding means adds the arc voltage control amount to the arc current control amount to obtain a control amount,
The DC / AC conversion means operates such that the semiconductor switch increases the arc current when the control amount increases. The control means further includes a current negative feedback control means and a second subtraction means,
The current negative feedback control means includes a second filter for removing a direct current component of the arc current detection value;
A third adjusting means for amplifying the detected arc current value from which the direct current component has been removed and outputting it to the second subtracting means as a second arc current control amount;
The second subtracting means takes a difference between the arc current control amount and the second arc current control amount, and outputs the difference to the adding means instead of the arc current control amount. The power supply device for arc discharge according to claim 1.   2. The arc discharge power supply device according to claim 1, wherein the voltage positive feedback control unit further includes a limiter that limits the output of the voltage positive feedback control unit to be always zero or more.   3. The arc discharge power supply device according to claim 2, wherein the voltage positive feedback control unit further includes a limiter that limits the output of the voltage positive feedback control unit to be always zero or more.

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