WO2019207627A1 - Power supply device - Google Patents

Power supply device Download PDF

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Publication number
WO2019207627A1
WO2019207627A1 PCT/JP2018/016458 JP2018016458W WO2019207627A1 WO 2019207627 A1 WO2019207627 A1 WO 2019207627A1 JP 2018016458 W JP2018016458 W JP 2018016458W WO 2019207627 A1 WO2019207627 A1 WO 2019207627A1
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WO
WIPO (PCT)
Prior art keywords
inverter
operation mode
voltage
power supply
supply device
Prior art date
Application number
PCT/JP2018/016458
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French (fr)
Japanese (ja)
Inventor
村上　哲
岩蕗　寛康
亮祐 小林
松原　真人
Original Assignee
三菱電機株式会社
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to PCT/JP2018/016458 priority Critical patent/WO2019207627A1/en
Priority to JP2018536218A priority patent/JP6399273B1/en
Publication of WO2019207627A1 publication Critical patent/WO2019207627A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
    • H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
    • H01S3/131—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling the active medium, e.g. by controlling the processes or apparatus for excitation
    • H01S3/134—Stabilisation of laser output parameters, e.g. frequency or amplitude by controlling the active medium, e.g. by controlling the processes or apparatus for excitation in gas lasers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present invention relates to a power supply device that supplies a high frequency voltage to a load, and more particularly to a power supply device that supplies a high frequency voltage to a discharge electrode and discharges it to generate laser light.
  • the primary side is connected in parallel using a plurality of transformers, and the secondary side is connected in series.
  • the structure is taken (for example, refer patent document 1).
  • the boost converter which is the input voltage of the inverter, is adjusted so that the laser is not oscillated and discharge is maintained, and the inverter is intermittently operated by group pulse operation to flow load current.
  • a technique for reducing the switching loss of a boost converter is disclosed (see, for example, Patent Document 2).
  • JP 2003-125586 A Japanese Patent Laid-Open No. 2003-243749
  • the power supply device disclosed in Patent Document 1 has an idea of adjusting the secondary side voltage of the transformer that is a voltage source of the discharge electrode that is a load, such as laser oscillation and laser non-oscillation and maintaining discharge. Not shown. Further, in the configuration of the power supply device disclosed in Patent Document 2, the boosting converter, which is the input voltage of the inverter, is adjusted so that the discharge electrode is adjusted so as to maintain discharge while the laser does not oscillate, and the group pulse operation is performed. Although a technique for reducing the switching loss of the inverter by performing the intermittent operation is shown, the idea of reducing the switching loss of the inverter that occurs when the group pulse is intermittently operated is not shown.
  • a power supply for a laser processing machine optimizes the intensity and energy amount of a laser according to the material of the workpiece in order to perform fine processing efficiently and at high speed on the workpiece such as a printed circuit board.
  • the peak value of the discharge power of the laser pulse it is necessary to control the peak value of the discharge power of the laser pulse, the repetition pulse frequency of the laser pulse, the pulse width of the laser pulse output, etc.
  • the repetition frequency of the laser pulse It is necessary to increase the repetition frequency of the group pulse.
  • the loss of the semiconductor constituting the inverter is a problem, and the repetition frequency of the group pulse cannot be increased.
  • the present invention has been made to solve the above-described problems, and in a laser non-oscillation state, a plurality of inverters are selectively operated to continuously flow a resonance current maintained by discharge.
  • An object of the present invention is to provide a power supply device that can reduce switching loss when an inverter is turned on during group pulse operation during laser oscillation.
  • the power supply device is connected to an AC power source, converts an AC voltage input from the AC power source into a DC voltage, and is connected in parallel to the AC / DC conversion unit.
  • a plurality of inverter circuits that convert the DC voltage converted by the DC / DC converter into an AC voltage, and a plurality of transformers in which each of the primary windings is connected to the plurality of inverter circuits, and each of the secondary windings is connected in series.
  • a resonance circuit having one end connected to the secondary windings of a plurality of transformers connected in series and the other end connected to a load, and a control circuit that controls the plurality of inverter circuits.
  • the inverter when the laser is not oscillating, the inverter is selectively operated, and the resonance current is continuously supplied to the inverter group, so that the semiconductor switching loss can be reduced.
  • FIG. 1 is a configuration diagram of a power supply device according to Embodiment 1 of the present invention.
  • the same or equivalent components are denoted by the same reference numerals.
  • ⁇ when there are a plurality of identical or equivalent components such as an inverter circuit, “ ⁇ ” and a number are added and distinguished as in the inverter circuit 23-1. In the case where the components are not distinguished or collectively referred to, description will be made by omitting “ ⁇ ” and the numeral as in the inverter circuit 23, for example.
  • the power supply device 2 includes an AC / DC conversion unit 20, a link capacitor 21, an inverter group 22, a transformer group 24, and a resonance circuit 26, and one end of the AC / DC conversion unit 20 is connected to the AC power source 1 to resonate. One end of the circuit 26 is connected to the discharge electrode 3.
  • the AC / DC converter 20 may be any circuit as long as it can convert an AC voltage into a DC voltage, but may be an AC / DC converter including four switching elements configured in a full bridge type, for example.
  • the link capacitor 21 is connected to a DC bus connecting the DC side terminal of the AC / DC converter 20 and an inverter group 22 described later. One end of the link capacitor 21 is connected to the positive side of the DC bus and the other end. Is connected to the negative electrode side of the DC bus.
  • the inverter group 22 has a plurality of inverter circuits 23-1 to 23-n, and the inverter circuits 23-1 to 23-n are connected in parallel to the AC / DC converter 20. That is, the DC terminals of the inverter circuits 23-1 to 23-n are connected to the DC bus.
  • n is an integer of 2 or more.
  • Each of the plurality of inverter circuits 23-1 to 23-n can transmit power in both directions, and converts the DC power output from the AC / DC conversion unit 20 through the link capacitor 21 into AC power to convert the transformer group 24 In addition, the AC power output from the transformer group 24 can be converted to DC power and output to the AC / DC converter 20.
  • FIG. 2 shows a configuration example of one unit of the inverter circuits 23-1 to 23 -n constituting the inverter group 22.
  • the inverter circuit 23 shown in FIG. 2 (a) includes four switching elements 23a to 23d connected in a full bridge type and a DC capacitor 23e, and two sets of switching elements (switching elements 23a) And 23d and switching elements 23b and 23c) are alternately turned on and off to convert a DC voltage and an AC voltage.
  • Each of the switching elements 23a to 23d constituting the inverter circuit 23 includes a diode connected in antiparallel. This diode may be a diode built in the switching element, or may be a diode externally attached to each switching element.
  • an inverter circuit having two switching elements 23a to 23b connected in a half-bridge type and DC capacitors 23e to 23g may be used.
  • the switching elements 23a to 23b of the inverter circuit shown in FIG. 2B include diodes connected in antiparallel.
  • the inverter circuit 23 may be any circuit as long as it has a switching element and can convert alternating current and direct current in both directions.
  • the transformer group 24 includes a plurality of transformers 25-1 to 25-n, and each of the transformers 25-1 to 25-n includes a primary winding and a secondary winding that can be magnetically coupled to each other.
  • the primary windings of the transformers 25-1 to 25-n are connected to the AC side terminals of the inverter circuits 23-1 to 23-n, respectively.
  • the secondary windings of the transformers 25-1 to 25-n are connected in series. That is, one terminal of the secondary winding of the transformer 25-1 becomes an output terminal of the transformer group 24, and the other terminal of the secondary winding of the transformer 25-1 and one of the secondary windings of the transformer 25-2.
  • One terminal of the secondary winding of ⁇ n is connected to each other. Further, the other terminal of the transformer 25-n is the other output terminal.
  • the resonance circuit 26 includes a resonance coil 26a and a resonance coil 26b.
  • the resonance coil 26 a has one end connected to the output terminal of the transformer group 24 and the other end connected to the discharge electrode 3.
  • the resonance coil 26b has one end connected to the transformer 25-n and the other end connected to the discharge electrode 3.
  • the values of the resonance coil 26 a and the resonance coil 26 b are set so that they can resonate together with the capacitance component of the discharge electrode 3 when the discharge electrode 3 is discharged.
  • the resonance coil 26a or Any one of the resonance coils 26b may be used.
  • the resonance coil may be configured by the leakage inductance of the transformer group 24 and may not be physically provided.
  • the control circuit 27 transmits a control signal 28 to each of the plurality of inverter circuits 23 to control the plurality of inverter circuits 23. That is, by transmitting an on / off signal of a switching element included in the inverter circuit 23, each inverter circuit 23 is turned on or off, and the voltage applied to the discharge electrode 3 is controlled.
  • the off state of the inverter circuits 23-1 to 23-n refers to a state in which the power transmission direction of the corresponding transformers 25-1 to 25-n flows from the secondary winding to the primary winding.
  • the inverter circuit shown in FIG. 2A is an upper arm reflux or lower arm switching in which the upper arm switching elements 23a and 23c are turned on. It also includes a lower arm reflux state in which the lower arms of the elements 23b and 23d are turned on.
  • the discharge electrode 3 is connected to the transformer group 24 via the resonance circuit 26, and discharges between the electrodes when a high frequency voltage is supplied, and laser oscillation occurs when a high voltage of a certain level or more is applied. Further, the discharge electrode 3 has a capacitance component and a resistance component, and resonates with the resonance circuit 26 at the time of discharge, so that a resonance current flows through the discharge electrode 3.
  • FIG. 3 illustrates the circuit operation of the inverter group 22 that causes the discharge electrode 3 to be in a laser oscillation or laser non-oscillation and discharge maintaining state using the power supply device according to the present embodiment.
  • the operation when the number of inverter circuits constituting the inverter group 22 is four as shown in FIG. 3, that is, when n is four in FIG. 1 will be described.
  • the midpoint of the secondary windings connected in series of the transformer group 24 is grounded. That is, the connection point between the secondary winding of the transformer 25-2 and the secondary winding of the transformer 25-3 is grounded.
  • the inverter circuit 23 is a full bridge type bidirectional inverter circuit shown in FIG.
  • the input voltage of the inverter circuits 23-1 to 23-4 is V in
  • the transformer ratio of each of the transformers 25-1 to 25-4 is 1: 1
  • the transformer output voltage required for laser oscillation at the discharge electrode 3 is 4V in
  • the transformer output voltage that allows the resonance current necessary for non-laser oscillation and discharge to be maintained at the discharge electrode 3 and zero voltage switching of the inverter circuits 23-1 to 4 to flow is 2V in .
  • the control circuit includes a first operation mode in which a plurality of inverter circuits 23 are turned on and a voltage is applied to the discharge electrode 3 that is a load, and a part of the plurality of inverter circuits 23. Control is performed using the second operation mode in which fewer inverter circuits are turned on than in the first operation mode. That is, during laser oscillation, all the inverter circuits 23-1 to 23-4 are turned on so that the voltage to the discharge electrode 3 is increased (first operation mode, FIG. 3A).
  • the discharge electrode 3 when the discharge electrode 3 is in the laser non-oscillation state and the discharge is maintained, the number of inverter circuits to be operated is decreased and at least one inverter circuit 23 is operated (second operation mode).
  • the two inverter circuits 23 are operated.
  • the voltage of the transformer group 24 in the second operation mode, is generated so as to be symmetric with respect to the ground reference. That is, by turning off inverter circuit 23-1 and inverter circuit 23-4 and turning on inverter circuit 23-2 and inverter circuit 23-3, the voltage generated at the output of transformer group 5 can be varied and discharged. The resonance current continues to flow while maintaining the discharge of the electrode 7 (FIG. 3B).
  • the voltage applied to the discharge electrode 3 is fixed with respect to the ground, and a symmetrical voltage is applied, so that unnecessary discharge and leakage current are less likely to occur.
  • the inverter circuit 23 does not need to be turned on or off with respect to the ground reference, and the inverter circuit 23 may be turned on or off asymmetrically with respect to the ground reference according to the voltage applied to the discharge electrode 3.
  • turning off the inverter circuit 23 refers to a state in which the power transmission direction of the transformers 25-1 to 25-n flows from the secondary winding to the primary winding, and all the switching elements in FIG.
  • the upper arm reflux in which the upper arm switching elements 23a and 23c are turned on, or the lower arm reflux in which the lower arms of the lower arm switching elements 23b and 23d are turned on In addition to the OFF state, in FIG. 2A, the upper arm reflux in which the upper arm switching elements 23a and 23c are turned on, or the lower arm reflux in which the lower arms of the lower arm switching elements 23b and 23d are turned on. Including the state that is. Even when the switching element of the inverter circuit is in the off state, the resonance current input from the transformer group 24 via the built-in diode provided in the inverter circuit 23 is output to the link capacitor 21 side.
  • the inverter circuit 23 when the inverter circuit 23 is turned on, the DC voltage supplied from the AC power supply 1 via the AC / DC converter 20 is converted into an AC voltage by ON / OFF control of the switching elements constituting the inverter circuit 23. , To supply to the transformer 25-2. At this time, any control may be used for on / off control of the switching elements constituting the inverter circuit, for example, PWM (Pulse Width Modulation) control may be used.
  • PWM Pulse Width Modulation
  • FIG. 4 is a diagram showing the relationship between the state of the inverter circuit 23, the output voltage of the transformer group 24, and the secondary current of the transformer group 24.
  • the laser oscillation operation period ((a) in FIG. 4)
  • all of the inverter circuits 23-1 to 23-4 are turned on, and the output voltage from the transformer group 24 is 4V in .
  • the period in which the laser is not oscillated and the discharge is maintained ((b) in FIG. 4)
  • only the inverter circuits 23-2 and 3 are turned on, so that the output voltage from the transformer group 24 is 2V in .
  • the resonance current continuously flows through the discharge electrode 3, the inverter group 22, and the like.
  • the inverter circuits 23-1 and 4 which have been turned off are turned on, whereby the inverter circuit All of 23-1 to 23-4 are turned on.
  • the resonance current continues to flow, when the inverter circuits 23-1 and 23 are turned on, zero voltage switching is performed and switching loss can be reduced. For this reason, even if laser oscillation / non-oscillation is repeated, the switching loss at the time of turn-on of the inverter group 22 can be reduced, and the repetition frequency of laser oscillation can be increased, so that the processing time can be increased. Become.
  • the current flowing through the discharge electrode 3 can be regenerated to the link capacitor 21 via the inverter circuits 23-1 and 4 which are turned off when the laser is not oscillated and the discharge is maintained.
  • the inverter circuits 23-1 and 4 which are turned off when the laser is not oscillated and the discharge is maintained.
  • FIG. 5 is a diagram for explaining the phase relationship between the voltage and current of the inverter circuit 23.
  • the conventional power supply device when the discharge electrode is in a laser non-oscillation state, all the inverter circuits are turned off, so that the output voltage on the secondary side of the transformer is 0 and the current flowing through the inverter circuit is also 0. For this reason, when the discharge electrode is switched to the laser oscillation state and the switching element constituting each inverter circuit starts an on / off operation, hard switching is performed and switching loss cannot be suppressed.
  • the inverter circuits 23-2 and 3 are on, and the output of the transformer group 24 is discharged. cause the voltage 2V in to maintain the, and the resonance current to the inverter circuits 23-1 through 4 soft switched flows to the discharge electrode 3 and the inverter circuits 23-1 to 4.
  • This current is a resonance current when the resonance coils 26a and 26b and the discharge electrode 3 are operated at a frequency higher than the resonance frequency determined by the capacity when the discharge electrode 3 is maintaining the discharge, and is a leading phase with respect to the voltage of the inverter circuit 23. It has become a relationship.
  • FIG. 6 shows that when the inverter group 22 is turned on, soft switching is performed, and that the same current as that of the discharge electrode 3 is regenerated by the inverter circuit 23 being turned off.
  • SW1 to SW4 are used to show the current flow.
  • FIG. 6A shows the relationship between the gate signal of each switching element (SW 1 to SW 4) of the inverter circuit 23, the drain-source voltage of each switching element, and the current flowing through the transformer 25.
  • FIG. 6B is a diagram showing the switching state and current flow of the inverter group 22 at the operating point a shown in FIG. In the power supply device shown in the present embodiment, the operations of inverter circuits 23-3 and 4 are omitted because they are symmetrical with respect to ground.
  • the operating point a corresponds to SW1 and SW4 of the inverter circuit 23-2 when the discharge electrode 3 is in a laser non-oscillation and discharge maintaining state (second operation mode, inverter circuit 23-1: OFF, inverter circuit 23-2: ON). Is the timing when is turned on. A negative current flows through the transformer 25, and power is regenerated in the link capacitor 21 via the built-in diodes of SW1 and SW4 of the inverter circuit 23-2. At this time, SW1 and SW4 of the inverter circuit 23-2 are turned on in a state where the built-in diode is turned on, so that it becomes a zero voltage switch, which indicates that switching loss can be reduced.
  • the operating point b is the timing at which SW2 and SW3 of the inverter circuit 23-2 are turned on when the discharge electrode 3 is in a laser non-oscillation and discharge maintenance state (inverter circuit 23-1: off, inverter circuit 23-2: on). It is. A positive current flows through the transformer 25, and power is regenerated to the link capacitor 21 via the built-in diodes of SW2 and SW3 of the inverter circuit 23-2. At this time, since SW2 and SW3 of the inverter circuit 23-2 are turned on in a state where the built-in diode is turned on, it becomes a zero voltage switch, and switching loss can be reduced as in the case of the operating point a.
  • the inverter circuit 23-2 is turned on and the inverter circuit 23-1 is turned off has been described here, the same effect can be obtained in the opposite case.
  • an inverter circuit 23 different from the inverter circuit 23 that was turned on in the previous second operation mode may be turned on.
  • the inverter circuits 23-1 and 4 are turned off in a certain laser non-oscillation and discharge sustaining state, and the inverter circuits 23-2 and 3 are turned off at the timing when the next laser non-oscillation and discharge sustaining state are established.
  • ON / OFF of each inverter circuit 23 is repeated alternately, and the loss of the inverter circuit 23 can be distributed.
  • FIG. 7 is a diagram schematically showing a method for adjusting the output voltage of the power supply device 2, that is, the voltage applied to the discharge electrode 3.
  • the discharge electrode voltage can be adjusted by controlling the number of inverter circuits 23 to be operated among the inverter circuits 23 constituting the inverter group 22.
  • the maximum voltage can be obtained by turning on the n inverter circuits 23 among the n inverter circuits 23, and in order to lower the discharge electrode voltage, the inverter circuit 23 to be operated is operated.
  • the discharge electrode voltage can be lowered by reducing the number (four in FIG. 6).
  • FIG. 8 is a diagram schematically showing a method for adjusting the average laser output during laser oscillation of the discharge electrode 3.
  • the average laser output can be adjusted by adjusting the ON period of the inverter circuit 23. That is, in the laser oscillation state of the discharge electrode 3, the laser output can be increased by increasing the ON period of each inverter circuit 23, and conversely, the laser output can be decreased by shortening the ON period of each inverter circuit 23. can do.
  • FIG. 9 shows the operation state by the applied voltage to the discharge electrode 3, and when the applied voltage is increased, the discharge is stopped and the laser is not oscillated and the discharge is maintained. From this laser non-oscillation laser non-oscillation and discharge sustaining state, when the voltage is further increased, the laser oscillation state is indicated. In addition, if the discharge is maintained, the resonance frequency remains almost unchanged between the time of laser oscillation and the time of laser non-oscillation.
  • each of them is connected in parallel, and a plurality of inverter circuits that convert a DC voltage into an AC voltage and each of the primary windings are connected to a plurality of inverter circuits,
  • a plurality of isolation transformers each having a secondary winding connected in series, a resonance circuit having one end connected to a secondary winding of each of the plurality of isolation transformers connected in series and the other end connected to a load, and an inverter circuit
  • a control circuit for controlling, and among the plurality of inverter circuits, the number of inverter circuits to be operated is changed to control the voltage applied to the load, and the load is a discharge electrode that emits laser light.
  • the switching electrode can reduce switching loss when the laser is not oscillating.
  • Embodiment 2 In the power supply device shown in the first embodiment, the output voltage output to the load is controlled by changing the number of inverter circuits 23 to be turned on among the plurality of inverter circuits 23 constituting the inverter group 22. In the power supply device shown in the second embodiment, in addition to changing the number of inverter circuits 23 to be turned on, the output voltage output to the load is controlled by shifting the operation phase of the inverter circuit to be turned on.
  • the power supply device shown in the second embodiment has the same configuration as the power supply device shown in FIG. 1 described in the first embodiment, and a description thereof will be omitted.
  • the plurality of inverter circuits 23 are controlled so that the output voltages of the inverter circuits 23 to be turned on are in phase in the first operation mode and the second operation mode.
  • the phase of the output voltage of the inverter circuit 23 that is turned on is adjusted by shifting it with the control circuit 27, and the variable range of the voltage applied to the discharge electrode 3 is widened.
  • Fig. 9 shows that when the phase of the inverter is shifted, the applied voltage of the discharge electrode decreases and can be adjusted.
  • the phase shift between the ON inverter circuits 23 (INV1 to 3) is increased in FIG. 9A
  • the phase shift between the ON inverter circuits 23 (INV1 to 3) is reduced in FIG. 9A.
  • the output voltage can be lowered by increasing the phase of the output voltage of the plurality of inverter circuits 23 to be turned on, and the output voltage of the plurality of inverter circuits 23 can be reduced.
  • the total output voltage output from the inverter circuit can be adjusted. That is, by adjusting the phase of each inverter circuit 23, the variable range of the applied voltage to the discharge electrode 3 can be widened or finely adjusted.
  • the power supply device shown in Embodiment 2 has the above-described configuration and operation, when the load is a discharge electrode that emits laser light as in the case of Embodiment 1, the discharge electrode is not laser-oscillated. Switching loss at the time can be reduced. Further, by adjusting the phase of the plurality of inverter circuits that are turned on, it is possible to obtain an effect that the variable range of the applied voltage to the discharge electrode is widened or that the applied voltage can be finely adjusted.

Abstract

A power supply device characterized by comprising: an AC/DC converter that converts AC voltage inputted from an AC power supply to DC voltage; a plurality of inverter circuits that are connected in parallel to the AC/DC converter, the inverter circuits converting the DC voltage converted by the AC/DC converter to AC voltage; a plurality of transformers for which individual primary windings are connected to the plurality of inverter circuits, and individual secondary windings are serially connected; a resonance circuit for which one end is connected to the serially connected secondary windings of the plurality of transformers, and the other end is connected to a load; and a control circuit that controls the plurality of inverter circuits, the control circuit performing control using a first operating mode that turns on the plurality of inverter circuits and applies a voltage to the load, and a second operating mode that turns on some of the plurality of inverter circuits in a quantity that is less than the number of inverter circuits turned on in the first operating mode. The power supply device is capable of reducing switching loss in a semiconductor.

Description

電源装置Power supply
　この発明は、負荷に対して高周波電圧を供給する電源装置に関するものであり、特に放電電極に高周波電圧を供給し、放電させてレーザ光を発生させる電源装置に関するものである。 The present invention relates to a power supply device that supplies a high frequency voltage to a load, and more particularly to a power supply device that supplies a high frequency voltage to a discharge electrode and discharges it to generate laser light.
　炭酸ガスレーザ発振器などに使用されるプラズマ発生用電源装置として、放電電極に印加する高周波、高電圧を得るため、複数のトランスを用いて一次側を並列接続し、二次側を直列接続するような構成が取られている（例えば、特許文献１参照）。
　また、インバータ部を連続動作する以外に、インバータの入力電圧である昇圧コンバータを調整してレーザを非発振かつ放電を維持状態とし、インバータを群パルス動作による間欠動作させて負荷電流を流すことで、昇圧コンバータのスイッチング損失を低減させる技術が示されている（例えば、特許文献２参照）。 As a power supply for plasma generation used in carbon dioxide laser oscillators, etc., to obtain high frequency and high voltage applied to the discharge electrode, the primary side is connected in parallel using a plurality of transformers, and the secondary side is connected in series. The structure is taken (for example, refer patent document 1).
In addition to continuously operating the inverter unit, the boost converter, which is the input voltage of the inverter, is adjusted so that the laser is not oscillated and discharge is maintained, and the inverter is intermittently operated by group pulse operation to flow load current. A technique for reducing the switching loss of a boost converter is disclosed (see, for example, Patent Document 2).
特開２００３－１２５５８６号公報JP 2003-125586 A 特開２００３－２４３７４９号公報Japanese Patent Laid-Open No. 2003-243749
　しかしながら、特許文献１に示された電源装置は、レーザ発振およびレーザ非発振かつ放電を維持させる等のように、負荷である放電電極の電圧源であるトランスの二次側電圧を調整する考えが示されていない。また特許文献２に示された電源装置の構成では、インバータの入力電圧である昇圧コンバータを調整することで放電電極をレーザ非発振としながらも放電を維持するように調整し、また群パルス動作を間欠動作させてインバータのスイッチング損失を低減する技術が示されているが、群パルスを間欠動作させた時に生じるインバータのスイッチングロスを低減させる考えが示されていない。 However, the power supply device disclosed in Patent Document 1 has an idea of adjusting the secondary side voltage of the transformer that is a voltage source of the discharge electrode that is a load, such as laser oscillation and laser non-oscillation and maintaining discharge. Not shown. Further, in the configuration of the power supply device disclosed in Patent Document 2, the boosting converter, which is the input voltage of the inverter, is adjusted so that the discharge electrode is adjusted so as to maintain discharge while the laser does not oscillate, and the group pulse operation is performed. Although a technique for reducing the switching loss of the inverter by performing the intermittent operation is shown, the idea of reducing the switching loss of the inverter that occurs when the group pulse is intermittently operated is not shown.
　一般に、レーザ加工機用電源は、プリント基板などの被加工物に対して、効率良く高速に微細加工を行うために、被加工物の材質に応じてレーザの強度とエネルギー量とを最適化する必要がある。このためには、レーザパルスの放電電力のピーク値、レーザパルスの繰り返しパルス周波数、レーザパルス出力のパルス幅等をそれぞれ制御する必要があり、中でも加工時間を短縮するにはレーザパルスの繰り返し周波数となる群パルスの繰り返し周波数を高くする必要がある。しかしながら、インバータを構成する半導体の損失が課題で、群パルスの繰り返し周波数を高くすることが出来なかった。 In general, a power supply for a laser processing machine optimizes the intensity and energy amount of a laser according to the material of the workpiece in order to perform fine processing efficiently and at high speed on the workpiece such as a printed circuit board. There is a need. For this purpose, it is necessary to control the peak value of the discharge power of the laser pulse, the repetition pulse frequency of the laser pulse, the pulse width of the laser pulse output, etc. Especially, in order to shorten the processing time, the repetition frequency of the laser pulse It is necessary to increase the repetition frequency of the group pulse. However, the loss of the semiconductor constituting the inverter is a problem, and the repetition frequency of the group pulse cannot be increased.
　この発明は、上記のような課題を解決するために成されたものであって、レーザ非発振の状態で、複数のインバータを選択的に動作させ、放電が維持した共振電流を継続して流し、レーザ発振時の群パルス動作時のインバータのターンオン時のスイッチング損失を低現させた電源装置の提供を目的とする。 The present invention has been made to solve the above-described problems, and in a laser non-oscillation state, a plurality of inverters are selectively operated to continuously flow a resonance current maintained by discharge. An object of the present invention is to provide a power supply device that can reduce switching loss when an inverter is turned on during group pulse operation during laser oscillation.
　本発明に係る電源装置は、交流電源に接続され、交流電源から入力される交流電圧を直流電圧に変換するＡＣ／ＤＣ変換部と、それぞれＡＣ／ＤＣ変換部に対して並列に接続され、ＡＣ／ＤＣ変換部により変換された直流電圧を交流電圧に変換する複数のインバータ回路と、１次巻線のそれぞれが複数のインバータ回路に接続され、２次巻線がそれぞれ直列接続された複数のトランスと、直列接続された複数のトランスの２次巻線に一端が接続され、他端が負荷に接続された共振回路と、複数のインバータ回路を制御する制御回路と、を備え、制御回路は、複数のインバータ回路をオンとして負荷に電圧を印加する第１動作モードと、複数のインバータ回路の一部であって、第１動作モードにおいてオンとするインバータ回路の数より少ないインバータ回路をオンとする第２動作モードを用いて制御すること、を特徴とする。 The power supply device according to the present invention is connected to an AC power source, converts an AC voltage input from the AC power source into a DC voltage, and is connected in parallel to the AC / DC conversion unit. A plurality of inverter circuits that convert the DC voltage converted by the DC / DC converter into an AC voltage, and a plurality of transformers in which each of the primary windings is connected to the plurality of inverter circuits, and each of the secondary windings is connected in series. And a resonance circuit having one end connected to the secondary windings of a plurality of transformers connected in series and the other end connected to a load, and a control circuit that controls the plurality of inverter circuits. A first operation mode in which a plurality of inverter circuits are turned on and a voltage is applied to a load; and a number of inverter circuits that are part of the plurality of inverter circuits and are turned on in the first operation mode. Be controlled using the second operation mode to the inverter circuit are on and characterized.
　本発明に係る電源装置では、レーザ非発振時、選択的にインバータを動作させ、インバータ群に共振電流を継続して流すことより、半導体のスイッチング損失を低減させることができる。 In the power supply device according to the present invention, when the laser is not oscillating, the inverter is selectively operated, and the resonance current is continuously supplied to the inverter group, so that the semiconductor switching loss can be reduced.
本発明の実施の形態１に示す電源装置の構成を示す回路図である。It is a circuit diagram which shows the structure of the power supply device shown in Embodiment 1 of this invention. 本発明の実施の形態１に示す電源装置のインバータ回路の構成例を示す図である。It is a figure which shows the structural example of the inverter circuit of the power supply device shown in Embodiment 1 of this invention. 本発明の実施の形態１に示す電源装置の動作を説明する図である。It is a figure explaining operation | movement of the power supply device shown in Embodiment 1 of this invention. 本発明の実施の形態１に示す電源装置の動作を説明する図である。It is a figure explaining operation | movement of the power supply device shown in Embodiment 1 of this invention. 本発明の実施の形態１に示す電源装置のインバータ回路の電圧と電流の位相関係を説明する図である。It is a figure explaining the phase relationship of the voltage and electric current of the inverter circuit of the power supply device shown in Embodiment 1 of this invention. 本発明の実施の形態１に示す電源装置のインバータ回路の動作を説明する図である。It is a figure explaining operation | movement of the inverter circuit of the power supply device shown in Embodiment 1 of this invention. 本発明の実施の形態１に示す電源装置のインバータを動作させる段数により放電電極の電圧が増減することを説明する図である。It is a figure explaining that the voltage of a discharge electrode increases / decreases with the stage number which operates the inverter of the power supply device shown in Embodiment 1 of this invention. 本発明の実施の形態１によるインバータの動作期間によりレーザ出力が変化することを説明する図である。It is a figure explaining a laser output changing with the operation | movement period of the inverter by Embodiment 1 of this invention. 本発明の実施の形態１による放電電極への印加電圧による状態を説明する図である。It is a figure explaining the state by the applied voltage to the discharge electrode by Embodiment 1 of this invention. 本発明の実施の形態２にインバータの位相をずらすことで放電電極への電圧調整が可能となることを説明する図である。It is a figure explaining that the voltage adjustment to a discharge electrode becomes possible by shifting the phase of an inverter in Embodiment 2 of the present invention.
実施の形態１．
　本発明の実施の形態１に係る電源装置について、図面を用いて説明する。本実施の形態においては、高周波電圧を供給する負荷としてレーザ光を発光する放電電極を用いた場合について説明する。図１は、本発明の実施の形態１に係る電源装置の構成図である。図面または以下の説明において、同一または相当の構成要素を示す場合には同一の符号を付すものとする。また、インバータ回路のように、同一または相当の構成要素が複数存在する場合には、インバータ回路２３－１のように「－」と数字を付して区別する。なお、各構成要素を区別しない場合、または、総称する場合には、例えば、インバータ回路２３のように、「－」と数字を省略して説明する。 Embodiment 1 FIG.
A power supply apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. In the present embodiment, a case will be described in which a discharge electrode that emits laser light is used as a load for supplying a high-frequency voltage. FIG. 1 is a configuration diagram of a power supply device according to Embodiment 1 of the present invention. In the drawings or the following description, the same or equivalent components are denoted by the same reference numerals. In addition, when there are a plurality of identical or equivalent components such as an inverter circuit, “−” and a number are added and distinguished as in the inverter circuit 23-1. In the case where the components are not distinguished or collectively referred to, description will be made by omitting “−” and the numeral as in the inverter circuit 23, for example.
　図１に示す電源装置２は、交流電源１および放電電極３と接続されており、交流電源１からの入力電圧を高周波電圧に変換し、放電電極３に出力する。電源装置２は、ＡＣ／ＤＣ変換部２０、リンクコンデンサ２１、インバータ群２２、トランス群２４、および共振回路２６を備えており、ＡＣ／ＤＣ変換部２０の一端が交流電源１に接続され、共振回路２６の一端が放電電極３に接続されている。 1 is connected to an AC power source 1 and a discharge electrode 3, and converts an input voltage from the AC power source 1 into a high-frequency voltage and outputs it to the discharge electrode 3. The power supply device 2 includes an AC / DC conversion unit 20, a link capacitor 21, an inverter group 22, a transformer group 24, and a resonance circuit 26, and one end of the AC / DC conversion unit 20 is connected to the AC power source 1 to resonate. One end of the circuit 26 is connected to the discharge electrode 3.
　ＡＣ／ＤＣ変換部２０は、一端（交流側端子）が交流電源１に接続されており、交流電源１から入力される交流電圧を直流電圧に変換し、他端（直流側端子）から出力する電力変換回路である。ＡＣ／ＤＣ変換部２０は、交流電圧を直流電圧に変換できればどのような回路でもよいが、例えば、フルブリッジ型に構成された４つのスイッチング素子からなるＡＣ／ＤＣ変換器としてもよい。 One end (AC side terminal) of the AC / DC converter 20 is connected to the AC power source 1, converts the AC voltage input from the AC power source 1 into a DC voltage, and outputs the DC voltage from the other end (DC side terminal). It is a power conversion circuit. The AC / DC converter 20 may be any circuit as long as it can convert an AC voltage into a DC voltage, but may be an AC / DC converter including four switching elements configured in a full bridge type, for example.
　リンクコンデンサ２１は、ＡＣ／ＤＣ変換部２０の直流側端子と後述するインバータ群２２とを接続する直流母線に接続されており、リンクコンデンサ２１の一端が直流母線の正極側に接続され、他端が直流母線の負極側に接続されている。 The link capacitor 21 is connected to a DC bus connecting the DC side terminal of the AC / DC converter 20 and an inverter group 22 described later. One end of the link capacitor 21 is connected to the positive side of the DC bus and the other end. Is connected to the negative electrode side of the DC bus.
　インバータ群２２は、一端（直流側端子）が直流母線を介してＡＣ／ＤＣ変換部２０およびリンクコンデンサ２１と接続されており、他端（交流側端子）が後述するトランス群２４に接続されている。インバータ群２２は、複数のインバータ回路２３－１～ｎを有しており、インバータ回路２３－１～ｎはＡＣ／ＤＣ変換部２０に対してそれぞれ並列接続されている。すなわち、インバータ回路２３－１～ｎのそれぞれの直流側端子は、直流母線に接続されている。ここで、ｎは２以上の整数である。複数のインバータ回路２３－１～ｎは、それぞれ双方向に電力伝送が可能であり、ＡＣ／ＤＣ変換部２０からリンクコンデンサ２１を介して出力された直流電力を交流電力に変換してトランス群２４に出力可能であり、また、トランス群２４から出力された交流電力を直流電力に変換してＡＣ／ＤＣ変換部２０に出力することが可能である。 One end (DC side terminal) of the inverter group 22 is connected to the AC / DC converter 20 and the link capacitor 21 via a DC bus, and the other end (AC side terminal) is connected to a transformer group 24 described later. Yes. The inverter group 22 has a plurality of inverter circuits 23-1 to 23-n, and the inverter circuits 23-1 to 23-n are connected in parallel to the AC / DC converter 20. That is, the DC terminals of the inverter circuits 23-1 to 23-n are connected to the DC bus. Here, n is an integer of 2 or more. Each of the plurality of inverter circuits 23-1 to 23-n can transmit power in both directions, and converts the DC power output from the AC / DC conversion unit 20 through the link capacitor 21 into AC power to convert the transformer group 24 In addition, the AC power output from the transformer group 24 can be converted to DC power and output to the AC / DC converter 20.
　図２に、インバータ群２２を構成するインバータ回路２３－１～ｎの１ユニットの構成例を示す。図２（ａ）に示すインバータ回路２３は、フルブリッジ型に接続された４つのスイッチング素子２３ａ～２３ｄと、直流コンデンサ２３ｅとを備えており、対角となるスイッチング素子の２組（スイッチング素子２３ａと２３ｄ、スイッチング素子２３ｂと２３ｃ）を交互にオンオフさせることにより直流電圧と交流電圧とを変換させる。インバータ回路２３を構成する各スイッチング素子２３ａ～２３ｄは、逆並列に接続されたダイオードを備えている。このダイオードはスイッチング素子の内蔵ダイオードであってもよいし、各スイッチング素子に外付けされたダイオードであってもよい。以下の説明では、内蔵ダイオードとして説明する。また、図２（ｂ）に示すようハーフブリッジ型に接続された２つのスイッチング素子２３ａ～２３ｂと、直流コンデンサ２３ｅ～２３ｇを有するインバータ回路を用いてもよい。図２（ｂ）に示すインバータ回路のスイッチング素子２３ａ～２３ｂも同様に、逆並列に接続されたダイオードを備えている。なお、インバータ回路２３は、スイッチング素子を有し、双方向に交流と直流とを変換可能な回路であればどのようなものであってもよい。 FIG. 2 shows a configuration example of one unit of the inverter circuits 23-1 to 23 -n constituting the inverter group 22. The inverter circuit 23 shown in FIG. 2 (a) includes four switching elements 23a to 23d connected in a full bridge type and a DC capacitor 23e, and two sets of switching elements (switching elements 23a) And 23d and switching elements 23b and 23c) are alternately turned on and off to convert a DC voltage and an AC voltage. Each of the switching elements 23a to 23d constituting the inverter circuit 23 includes a diode connected in antiparallel. This diode may be a diode built in the switching element, or may be a diode externally attached to each switching element. In the following description, it will be described as a built-in diode. Further, as shown in FIG. 2B, an inverter circuit having two switching elements 23a to 23b connected in a half-bridge type and DC capacitors 23e to 23g may be used. Similarly, the switching elements 23a to 23b of the inverter circuit shown in FIG. 2B include diodes connected in antiparallel. The inverter circuit 23 may be any circuit as long as it has a switching element and can convert alternating current and direct current in both directions.
　トランス群２４は、複数のトランス２５－１～ｎを有しており、トランス２５－１～ｎは、互いに磁気的に結合可能な１次巻線と２次巻線をそれぞれ備えている。トランス２５－１～ｎの１次巻線は、それぞれインバータ回路２３－１～ｎの交流側端子に接続されている。また、トランス２５－１～ｎの２次巻線は、それぞれが直列に接続されている。すなわち、トランス２５－１の２次巻線の一方の端子がトランス群２４の出力端子となり、トランス２５－１の２次巻線の他方の端子とトランス２５－２の２次巻線の一方の端子、トランス２５－２の２次巻線の他方の端子とトランス２５－３の２次巻線の一方の端子、トランス２５－（ｎ－１）の２次巻線の一方の端子とトランス２５－ｎの２次巻線の一方の端子とがそれぞれ接続されている。また、トランス２５－ｎの他方の端子がもう一方の出力端子となっている。 The transformer group 24 includes a plurality of transformers 25-1 to 25-n, and each of the transformers 25-1 to 25-n includes a primary winding and a secondary winding that can be magnetically coupled to each other. The primary windings of the transformers 25-1 to 25-n are connected to the AC side terminals of the inverter circuits 23-1 to 23-n, respectively. The secondary windings of the transformers 25-1 to 25-n are connected in series. That is, one terminal of the secondary winding of the transformer 25-1 becomes an output terminal of the transformer group 24, and the other terminal of the secondary winding of the transformer 25-1 and one of the secondary windings of the transformer 25-2. Terminal, the other terminal of the secondary winding of the transformer 25-2 and one terminal of the secondary winding of the transformer 25-3, the one terminal of the secondary winding of the transformer 25- (n-1) and the transformer 25 One terminal of the secondary winding of −n is connected to each other. Further, the other terminal of the transformer 25-n is the other output terminal.
　共振回路２６は、共振コイル２６ａおよび共振コイル２６ｂを備えている。共振コイル２６ａは、一端がトランス群２４の出力端子に接続されており、他端が放電電極３に接続されている。同様に共振コイル２６ｂは、一端がトランス２５－ｎに接続されており、他端が放電電極３に接続されている。共振コイル２６ａおよび共振コイル２６ｂは、放電電極３の放電時において、放電電極３のキャパシタンス成分と合わせて共振可能なようにその値が設定されている。なお、図１に示す電源装置では、共振コイルを放電電極３の両端に２つ設けた構成について示したが、これに限ったものではなく、例えば、共振コイルを１つとし、共振コイル２６ａまたは共振コイル２６ｂのいずれか１つとしてもよい。また。共振コイルをトランス群２４の漏れインダクタンスで構成し、物理的に設けない構成としても構わない。 The resonance circuit 26 includes a resonance coil 26a and a resonance coil 26b. The resonance coil 26 a has one end connected to the output terminal of the transformer group 24 and the other end connected to the discharge electrode 3. Similarly, the resonance coil 26b has one end connected to the transformer 25-n and the other end connected to the discharge electrode 3. The values of the resonance coil 26 a and the resonance coil 26 b are set so that they can resonate together with the capacitance component of the discharge electrode 3 when the discharge electrode 3 is discharged. In the power supply device shown in FIG. 1, the configuration in which two resonance coils are provided at both ends of the discharge electrode 3 is shown. However, the present invention is not limited to this. For example, the resonance coil 26a or Any one of the resonance coils 26b may be used. Also. The resonance coil may be configured by the leakage inductance of the transformer group 24 and may not be physically provided.
　制御回路２７は、複数のインバータ回路２３に対し、それぞれ制御信号２８を送信し、複数のインバータ回路２３を制御する。すなわち、インバータ回路２３が有するスイッチング素子のオンオフ信号を送信することにより、各インバータ回路２３をオンまたはオフの状態にし、放電電極３に印加する電圧を制御する。ここで、インバータ回路２３－１～ｎのオフの状態とは、対応するトランス２５－１～ｎの電力伝送方向が２次側巻線から１次側巻線の方向に電流が流れる状態を指し、図２に示すスイッチング素子が全てオフしている状態に加え、図２（ａ）に示すインバータ回路であれば、上アームのスイッチング素子２３ａ、２３ｃがオンする上アーム還流、もしくは下アームのスイッチング素子２３ｂ、２３ｄの下アームがオンする下アーム還流の状態も含む。 The control circuit 27 transmits a control signal 28 to each of the plurality of inverter circuits 23 to control the plurality of inverter circuits 23. That is, by transmitting an on / off signal of a switching element included in the inverter circuit 23, each inverter circuit 23 is turned on or off, and the voltage applied to the discharge electrode 3 is controlled. Here, the off state of the inverter circuits 23-1 to 23-n refers to a state in which the power transmission direction of the corresponding transformers 25-1 to 25-n flows from the secondary winding to the primary winding. In addition to the state in which all the switching elements shown in FIG. 2 are off, the inverter circuit shown in FIG. 2A is an upper arm reflux or lower arm switching in which the upper arm switching elements 23a and 23c are turned on. It also includes a lower arm reflux state in which the lower arms of the elements 23b and 23d are turned on.
　放電電極３は、共振回路２６を介してトランス群２４と接続されており、高周波電圧が供給されることにより電極間で放電を行い、一定以上の高電圧がかかることによりレーザ発振する。また、放電電極３は、キャパシタンス成分および抵抗成分を有しており、共振回路２６とともに放電時に共振し、放電電極３に共振電流が流れることとなる。 The discharge electrode 3 is connected to the transformer group 24 via the resonance circuit 26, and discharges between the electrodes when a high frequency voltage is supplied, and laser oscillation occurs when a high voltage of a certain level or more is applied. Further, the discharge electrode 3 has a capacitance component and a resistance component, and resonates with the resonance circuit 26 at the time of discharge, so that a resonance current flows through the discharge electrode 3.
　次に、本実施の形態に係る電源装置の動作について説明する。
　図３は、本実施の形態に係る電源装置を用いて、放電電極３を、レーザ発振またはレーザ非発振かつ放電維持の状態にさせるインバータ群２２の回路動作について説明したものである。ここでは一例として、図３に示すようにインバータ群２２を構成するインバータ回路の数を４個で構成した場合、すなわち図１においてｎを４とした場合の動作について説明する。ここで、図３に示すようにトランス群２４の直列に接続された２次巻線の中点が対接地されている。すなわち、トランス２５－２の２次巻線とトランス２５－３の２次巻線との接続点が接地されている。また、インバータ回路２３は、図２（ａ）に示すフルブリッジ型の双方向インバータ回路を用いるものとする。 Next, the operation of the power supply device according to the present embodiment will be described.
FIG. 3 illustrates the circuit operation of the inverter group 22 that causes the discharge electrode 3 to be in a laser oscillation or laser non-oscillation and discharge maintaining state using the power supply device according to the present embodiment. Here, as an example, the operation when the number of inverter circuits constituting the inverter group 22 is four as shown in FIG. 3, that is, when n is four in FIG. 1 will be described. Here, as shown in FIG. 3, the midpoint of the secondary windings connected in series of the transformer group 24 is grounded. That is, the connection point between the secondary winding of the transformer 25-2 and the secondary winding of the transformer 25-3 is grounded. The inverter circuit 23 is a full bridge type bidirectional inverter circuit shown in FIG.
　ここでは、インバータ回路２３－１～４の入力電圧をＶｉｎ、トランス２５－１～４のそれぞれのトランス比を１：１とし、放電電極３におけるレーザ発振に必要なトランス出力電圧を４Ｖｉｎ、放電電極３においてレーザ非発振かつ放電を維持し、インバータ回路２３－１～４をゼロ電圧スイッチングさせるために必要な共振電流を流せるトランス出力電圧を２Ｖｉｎとして説明する。 Here, the input voltage of the inverter circuits 23-1 to 23-4 is V in , the transformer ratio of each of the transformers 25-1 to 25-4 is 1: 1, and the transformer output voltage required for laser oscillation at the discharge electrode 3 is 4V in , In the following description, it is assumed that the transformer output voltage that allows the resonance current necessary for non-laser oscillation and discharge to be maintained at the discharge electrode 3 and zero voltage switching of the inverter circuits 23-1 to 4 to flow is 2V in .
　本実施の形態に示す電源装置において、制御回路は、複数のインバータ回路２３をオンとして負荷である放電電極３に電圧を印加する第１動作モードと、複数のインバータ回路２３の一部であって、第１動作モードにおいてオンとするインバータ回路の数より少ないインバータ回路をオンとする第２動作モードを用いて制御する。すなわち、レーザ発振時には放電電極３への電圧が高くなるようインバータ回路２３－１～４を全てオンさせる（第１動作モード、図３（ａ））。また、放電電極３をレーザ非発振かつ放電維持の状態の場合、動作させるインバータ回路の数を減少させ、少なくとも１つのインバータ回路２３を動作させる（第２動作モード）。ここでは２つのインバータ回路２３を動作させる。また、本実施の形態に示す電源装置では、第２動作モードにおいて、接地基準で対称となるようにトランス群２４の電圧を発生させる。すなわち、インバータ回路２３－１およびインバータ回路２３－４をオフとし、インバータ回路２３－２およびインバータ回路２３－３をオンとすることにより、トランス群５の出力に発生する電圧を可変し、かつ放電電極７の放電を維持しつつ共振電流を流し続ける（図３（ｂ））。これにより、放電電極３への印加電圧がアース基準で固定され、対称電圧がかかるため不要な放電やリーク電流等が生じにくくなる。なお、接地基準で対象にインバータ回路２３をオンまたはオフとする必要はなく、放電電極３に印加する電圧に応じて接地基準で非対称にインバータ回路２３をオンまたはオフとしてもよい。 In the power supply device shown in the present embodiment, the control circuit includes a first operation mode in which a plurality of inverter circuits 23 are turned on and a voltage is applied to the discharge electrode 3 that is a load, and a part of the plurality of inverter circuits 23. Control is performed using the second operation mode in which fewer inverter circuits are turned on than in the first operation mode. That is, during laser oscillation, all the inverter circuits 23-1 to 23-4 are turned on so that the voltage to the discharge electrode 3 is increased (first operation mode, FIG. 3A). Further, when the discharge electrode 3 is in the laser non-oscillation state and the discharge is maintained, the number of inverter circuits to be operated is decreased and at least one inverter circuit 23 is operated (second operation mode). Here, the two inverter circuits 23 are operated. In the power supply device shown in the present embodiment, in the second operation mode, the voltage of the transformer group 24 is generated so as to be symmetric with respect to the ground reference. That is, by turning off inverter circuit 23-1 and inverter circuit 23-4 and turning on inverter circuit 23-2 and inverter circuit 23-3, the voltage generated at the output of transformer group 5 can be varied and discharged. The resonance current continues to flow while maintaining the discharge of the electrode 7 (FIG. 3B). As a result, the voltage applied to the discharge electrode 3 is fixed with respect to the ground, and a symmetrical voltage is applied, so that unnecessary discharge and leakage current are less likely to occur. The inverter circuit 23 does not need to be turned on or off with respect to the ground reference, and the inverter circuit 23 may be turned on or off asymmetrically with respect to the ground reference according to the voltage applied to the discharge electrode 3.
　ここで、インバータ回路２３をオフさせるとは、トランス２５－１～ｎの電力伝送方向が二次側巻線から一次側巻線の方向に電流が流れる状態を指し、図２のスイッチング素子が全てオフしている状態に加え、図２（ａ）であれば、上アームのスイッチング素子２３ａ、２３ｃがオンする上アーム還流、もしくは下アームのスイッチング素子２３ｂ、２３ｄの下アームがオンする下アーム還流している状態をも含む。なお、インバータ回路のスイッチング素子がオフの状態であっても、インバータ回路２３が備える内蔵ダイオードを介してトランス群２４から入力される共振電流はリンクコンデンサ２１側に出力されることとなる。また、インバータ回路２３をオンとするとは、インバータ回路２３を構成するスイッチング素子をオンオフ制御することにより、交流電源１からＡＣ／ＤＣ変換部２０を介して供給された直流電圧を交流電圧に変換し、トランス２５－２に供給させることを指す。この時、インバータ回路を構成するスイッチング素子のオンオフ制御にはどのような制御を用いてもよく、例えば、ＰＷＭ（Pulse Width Modulation）制御を用いてもよい。 Here, turning off the inverter circuit 23 refers to a state in which the power transmission direction of the transformers 25-1 to 25-n flows from the secondary winding to the primary winding, and all the switching elements in FIG. In addition to the OFF state, in FIG. 2A, the upper arm reflux in which the upper arm switching elements 23a and 23c are turned on, or the lower arm reflux in which the lower arms of the lower arm switching elements 23b and 23d are turned on. Including the state that is. Even when the switching element of the inverter circuit is in the off state, the resonance current input from the transformer group 24 via the built-in diode provided in the inverter circuit 23 is output to the link capacitor 21 side. In addition, when the inverter circuit 23 is turned on, the DC voltage supplied from the AC power supply 1 via the AC / DC converter 20 is converted into an AC voltage by ON / OFF control of the switching elements constituting the inverter circuit 23. , To supply to the transformer 25-2. At this time, any control may be used for on / off control of the switching elements constituting the inverter circuit, for example, PWM (Pulse Width Modulation) control may be used.
　図４は、インバータ回路２３の状態とトランス群２４の出力電圧およびトランス群２４の二次側電流との関係を示す図である。図４に示すように、レーザ発振動作期間（図４中の（ａ））では、インバータ回路２３－１～４のすべてがオンとなり、トランス群２４からの出力電圧は４Ｖｉｎとなる。一方、レーザ非発振かつ放電維持状態の期間（図４中の（ｂ））では、インバータ回路２３－２，３のみがオンとなるためトランス群２４からの出力電圧は２Ｖｉｎとなり、レーザ非発振時においても共振電電流が放電電極３やインバータ群２２等を継続して流れることとなる。 FIG. 4 is a diagram showing the relationship between the state of the inverter circuit 23, the output voltage of the transformer group 24, and the secondary current of the transformer group 24. As shown in FIG. 4, in the laser oscillation operation period ((a) in FIG. 4), all of the inverter circuits 23-1 to 23-4 are turned on, and the output voltage from the transformer group 24 is 4V in . On the other hand, in the period in which the laser is not oscillated and the discharge is maintained ((b) in FIG. 4), only the inverter circuits 23-2 and 3 are turned on, so that the output voltage from the transformer group 24 is 2V in . Even at times, the resonance current continuously flows through the discharge electrode 3, the inverter group 22, and the like.
　第２動作モードから第１動作モードへ移行する場合、すなわち、放電電極３をレーザ非発振からレーザ発振に変化させる場合、オフとしていたインバータ回路２３－１，４をオンとすることにより、インバータ回路２３－１～４の全てがオンすることとなる。この時、共振電流が流れ続けているため、インバータ回路２３－１，４をターンオンさせる時はゼロ電圧スイッチングとなりスイッチング損失を低減させることができる。このため、レーザ発振／非発振を繰り返してもインバータ群２２のターンオン時のスイッチング損失を低減させることができ、レーザ発振の繰り返し周波数を高くすることができるため、加工時間の高速化が図れることになる。 When shifting from the second operation mode to the first operation mode, i.e., when changing the discharge electrode 3 from laser non-oscillation to laser oscillation, the inverter circuits 23-1 and 4 which have been turned off are turned on, whereby the inverter circuit All of 23-1 to 23-4 are turned on. At this time, since the resonance current continues to flow, when the inverter circuits 23-1 and 23 are turned on, zero voltage switching is performed and switching loss can be reduced. For this reason, even if laser oscillation / non-oscillation is repeated, the switching loss at the time of turn-on of the inverter group 22 can be reduced, and the repetition frequency of laser oscillation can be increased, so that the processing time can be increased. Become.
　また、第２動作モードにおいて、レーザ非発振かつ放電維持の状態時にオフとなるインバータ回路２３－１，４を介して、放電電極３に流れる電流をリンクコンデンサ２１に電力回生できるため、ゼロ電圧スイッチを成立させるためにレーザ非発振かつ放電維持時に共振電流を流し続けることに対する損失増加を抑制することができる。 In the second operation mode, the current flowing through the discharge electrode 3 can be regenerated to the link capacitor 21 via the inverter circuits 23-1 and 4 which are turned off when the laser is not oscillated and the discharge is maintained. In order to establish the above, it is possible to suppress an increase in loss due to the non-oscillation of the laser and the continuous flow of the resonance current when the discharge is maintained.
　次に、図５を用いて、放電電極３がレーザ非発振状態からレーザ発振状態に切り替わる時の、トランス群２４の二次側電圧、インバータ回路２３の電流について説明する。図５は、インバータ回路２３の電圧と電流の位相関係を説明する図である。
　従来の電源装置では、放電電極がレーザ非発振の状態では、インバータ回路がすべてオフとなるため、トランスの二次側の出力電圧が０となり、インバータ回路に流れる電流も０となる。そのため、放電電極がレーザ発振状態に切り替わり、各インバータ回路を構成するスイッチング素子がオンオフ動作を開始する場合には、ハードスイッチングとなり、スイッチング損失を抑制することができない。 Next, the secondary voltage of the transformer group 24 and the current of the inverter circuit 23 when the discharge electrode 3 is switched from the laser non-oscillation state to the laser oscillation state will be described with reference to FIG. FIG. 5 is a diagram for explaining the phase relationship between the voltage and current of the inverter circuit 23.
In the conventional power supply device, when the discharge electrode is in a laser non-oscillation state, all the inverter circuits are turned off, so that the output voltage on the secondary side of the transformer is 0 and the current flowing through the inverter circuit is also 0. For this reason, when the discharge electrode is switched to the laser oscillation state and the switching element constituting each inverter circuit starts an on / off operation, hard switching is performed and switching loss cannot be suppressed.
　一方、本実施の形態に係る電源装置では、放電電極３がレーザ非発振かつ放電維持の状態の時は、インバータ回路２３－２，３がオンとなっており、トランス群２４の出力には放電を維持させる電圧２Ｖｉｎが生じ、かつ、インバータ回路２３－１～４をソフトスイッチングさせる共振電流が放電電極３やインバータ回路２３－１～４に流れている。この電流は、共振コイル２６ａ，２６ｂと放電電極３が放電を維持している時の容量で決まる共振周波数より高い周波数で動作させた場合の共振電流であり、インバータ回路２３の電圧に対し進み位相の関係となっている。そのため、放電電極３がレーザ発振状態に切り替わり、各インバータ回路２３を構成するスイッチング素子がオンオフ動作を開始する場合には、ソフトスイッチングが成立し、スイッチング損失を低減させることができる。従って、レーザ非発振の状態はもちろんのこと、レーザ非発振からレーザ発振状態となるときにおいてもターンオン時にソフトスイッチングが成立することとなる。 On the other hand, in the power supply device according to the present embodiment, when the discharge electrode 3 is in a laser non-oscillation state and the discharge is maintained, the inverter circuits 23-2 and 3 are on, and the output of the transformer group 24 is discharged. cause the voltage 2V in to maintain the, and the resonance current to the inverter circuits 23-1 through 4 soft switched flows to the discharge electrode 3 and the inverter circuits 23-1 to 4. This current is a resonance current when the resonance coils 26a and 26b and the discharge electrode 3 are operated at a frequency higher than the resonance frequency determined by the capacity when the discharge electrode 3 is maintaining the discharge, and is a leading phase with respect to the voltage of the inverter circuit 23. It has become a relationship. Therefore, when the discharge electrode 3 is switched to the laser oscillation state and the switching elements constituting each inverter circuit 23 start an on / off operation, soft switching is established and switching loss can be reduced. Therefore, not only the laser non-oscillation state but also the soft switching is established at the turn-on even when the laser oscillation state is changed from the laser non-oscillation state.
　図６は、インバータ群２２がターンオン時にソフトスイッチングになること、および、放電電極３と同じ電流が、オフしているインバータ回路２３により回生されることを、インバータ回路２３－１～４のスイッチング素子ＳＷ１～ＳＷ４を用い、電流の流れにより示したものである。図６（ａ）は、インバータ回路２３の各スイッチング素子（ＳＷ１～ＳＷ４）のゲート信号および各スイッチング素子のドレイン－ソース電圧およびトランス２５に流れる電流の関係を示したものである。また、図６（ｂ）は、図６（ａ）に示す動作点ａにおけるインバータ群２２のスイッチング状態と電流の流れを示した図である。なお、本実施の形態に示す電源装置では、接地を基準に対称となるためインバータ回路２３－３，４の動作は省略している。 FIG. 6 shows that when the inverter group 22 is turned on, soft switching is performed, and that the same current as that of the discharge electrode 3 is regenerated by the inverter circuit 23 being turned off. SW1 to SW4 are used to show the current flow. FIG. 6A shows the relationship between the gate signal of each switching element (SW 1 to SW 4) of the inverter circuit 23, the drain-source voltage of each switching element, and the current flowing through the transformer 25. FIG. 6B is a diagram showing the switching state and current flow of the inverter group 22 at the operating point a shown in FIG. In the power supply device shown in the present embodiment, the operations of inverter circuits 23-3 and 4 are omitted because they are symmetrical with respect to ground.
　動作点ａは、放電電極３がレーザ非発振かつ放電維持の状態（第２動作モード、インバータ回路２３－１：オフ、インバータ回路２３－２：オン）において、インバータ回路２３－２のＳＷ１、ＳＷ４がオンとなるタイミングである。トランス２５には負方向の電流が流れており、インバータ回路２３－２のＳＷ１、ＳＷ４の内蔵ダイオードを介してリンクコンデンサ２１に電力回生している。この時、内蔵ダイオードがオンとなる状態でインバータ回路２３－２のＳＷ１、ＳＷ４がターンオンするため、ゼロ電圧スイッチとなりスイッチング損失が低減できることを示す。また、インバータ回路２３－１のＳＷ１～４はオフであり、トランス２５のトランス比が１：１であるため、放電電極３に流れる電流と同じ大きさの電流がトランスの一次巻線に流れ、スイッチング素子ＳＷ１～ＳＷ４の内蔵ダイオード通じて整流され、リンクコンデンサ２１に電力回生されることとなる。 The operating point a corresponds to SW1 and SW4 of the inverter circuit 23-2 when the discharge electrode 3 is in a laser non-oscillation and discharge maintaining state (second operation mode, inverter circuit 23-1: OFF, inverter circuit 23-2: ON). Is the timing when is turned on. A negative current flows through the transformer 25, and power is regenerated in the link capacitor 21 via the built-in diodes of SW1 and SW4 of the inverter circuit 23-2. At this time, SW1 and SW4 of the inverter circuit 23-2 are turned on in a state where the built-in diode is turned on, so that it becomes a zero voltage switch, which indicates that switching loss can be reduced. Further, since SW1 to SW4 of the inverter circuit 23-1 are off and the transformer ratio of the transformer 25 is 1: 1, a current having the same magnitude as the current flowing to the discharge electrode 3 flows to the primary winding of the transformer. The current is rectified through the built-in diodes of the switching elements SW1 to SW4 and is regenerated in the link capacitor 21.
　動作点ｂは、放電電極３がレーザ非発振かつ放電維持の状態（インバータ回路２３－１：オフ、インバータ回路２３－２：オン）において、インバータ回路２３－２のＳＷ２、ＳＷ３がオンとなるタイミングである。トランス２５には正方向の電流が流れており、インバータ回路２３－２のＳＷ２、ＳＷ３の内蔵ダイオードを介してリンクコンデンサ２１に電力回生している。この時、内蔵ダイオードがオンとなる状態でインバータ回路２３－２のＳＷ２、ＳＷ３をターンオンするため、ゼロ電圧スイッチとなり、動作点ａの場合と同様にスイッチング損失を低減することができる。 The operating point b is the timing at which SW2 and SW3 of the inverter circuit 23-2 are turned on when the discharge electrode 3 is in a laser non-oscillation and discharge maintenance state (inverter circuit 23-1: off, inverter circuit 23-2: on). It is. A positive current flows through the transformer 25, and power is regenerated to the link capacitor 21 via the built-in diodes of SW2 and SW3 of the inverter circuit 23-2. At this time, since SW2 and SW3 of the inverter circuit 23-2 are turned on in a state where the built-in diode is turned on, it becomes a zero voltage switch, and switching loss can be reduced as in the case of the operating point a.
　なお、ここではインバータ回路２３－２をオン、インバータ回路２３－１をオフとする場合について説明したが、その逆の場合でも同様に効果が得られる。また、第１動作モードと第２動作モードを繰り返す場合に、第２動作モードにおいて、前回の第２動作モードにおいてオンとしたインバータ回路２３と異なるインバータ回路２３をオンとしてもよい。例えば、あるレーザ非発振かつ放電維持状態ではインバータ回路２３－１，４をオフとし、次のレーザ非発振かつ放電維持状態となるタイミングではインバータ回路２３－２，３をオフとし、これを交互に繰り返すことにより、各インバータ回路２３のオンオフが交互に繰り返され、インバータ回路２３の損失を分散することできる。 Although the case where the inverter circuit 23-2 is turned on and the inverter circuit 23-1 is turned off has been described here, the same effect can be obtained in the opposite case. Further, when the first operation mode and the second operation mode are repeated, in the second operation mode, an inverter circuit 23 different from the inverter circuit 23 that was turned on in the previous second operation mode may be turned on. For example, the inverter circuits 23-1 and 4 are turned off in a certain laser non-oscillation and discharge sustaining state, and the inverter circuits 23-2 and 3 are turned off at the timing when the next laser non-oscillation and discharge sustaining state are established. By repeating, ON / OFF of each inverter circuit 23 is repeated alternately, and the loss of the inverter circuit 23 can be distributed.
　図７は、電源装置２の出力電圧、すなわち放電電極３に印加する電圧の調整方法を模式的に示した図である。本実施の形態に示す電源装置では、インバータ群２２を構成するインバータ回路２３のうち動作させるインバータ回路２３の数を制御させることにより放電電極電圧を調整することができる。図６に示すように、ｎ個のインバータ回路２３のうちｎ個のインバータ回路２３をオンとすることにより最大の電圧を得ることができ、放電電極電圧を下げるためには動作させるインバータ回路２３の数を減らすことにより放電電極電圧を下げることができる（図６では４個）。 FIG. 7 is a diagram schematically showing a method for adjusting the output voltage of the power supply device 2, that is, the voltage applied to the discharge electrode 3. As shown in FIG. In the power supply device shown in the present embodiment, the discharge electrode voltage can be adjusted by controlling the number of inverter circuits 23 to be operated among the inverter circuits 23 constituting the inverter group 22. As shown in FIG. 6, the maximum voltage can be obtained by turning on the n inverter circuits 23 among the n inverter circuits 23, and in order to lower the discharge electrode voltage, the inverter circuit 23 to be operated is operated. The discharge electrode voltage can be lowered by reducing the number (four in FIG. 6).
　図８は、放電電極３のレーザ発振時における平均レーザ出力の調整方法を模式的に示した図である。本実施の形態に示す電源装置では、インバータ回路２３のオン期間を調整することにより平均レーザ出力を調整することができる。すなわち、放電電極３のレーザ発振状態において、各インバータ回路２３のオン期間を長くすることによりレーザ出力が高くすることができ、逆に各インバータ回路２３のオン期間を短くすることによりレーザ出力を低くすることができる。 FIG. 8 is a diagram schematically showing a method for adjusting the average laser output during laser oscillation of the discharge electrode 3. In the power supply device described in this embodiment, the average laser output can be adjusted by adjusting the ON period of the inverter circuit 23. That is, in the laser oscillation state of the discharge electrode 3, the laser output can be increased by increasing the ON period of each inverter circuit 23, and conversely, the laser output can be decreased by shortening the ON period of each inverter circuit 23. can do.
　図９は、放電電極３への印加電圧による動作状態を示しており、印加電圧をあげていくと、放電停止から放電を始めレーザ非発振かつ放電維持状態となる。このレーザ非発振レーザ非発振かつ放電維持状態から、さらに電圧を上げるとレーザ発振の状態となることを示す。また、放電を維持していれば、レーザ発振時とレーザ非発振時の時では共振周波数は殆ど変わらず一定であることを示している。 FIG. 9 shows the operation state by the applied voltage to the discharge electrode 3, and when the applied voltage is increased, the discharge is stopped and the laser is not oscillated and the discharge is maintained. From this laser non-oscillation laser non-oscillation and discharge sustaining state, when the voltage is further increased, the laser oscillation state is indicated. In addition, if the discharge is maintained, the resonance frequency remains almost unchanged between the time of laser oscillation and the time of laser non-oscillation.
　以上のように実施の形態１に示す電源装置では、それぞれが並列に接続され、直流電圧を交流電圧に変換する複数のインバータ回路と、１次巻線のそれぞれが複数のインバータ回路に接続され、２次巻線がそれぞれ直列接続された複数の絶縁トランスと、直列接続された複数の絶縁トランスの２次巻線に一端が接続され、他端が負荷に接続された共振回路と、インバータ回路を制御する制御回路と、を備え、複数のインバータ回路のうち、動作させるインバータ回路の数を変化させ、負荷へ印加する電圧を制御する構成となっており、負荷がレーザ光を発光する放電電極である場合、放電電極がレーザ非発振時におけるスイッチング損失を低減させることができる。 As described above, in the power supply device shown in Embodiment 1, each of them is connected in parallel, and a plurality of inverter circuits that convert a DC voltage into an AC voltage and each of the primary windings are connected to a plurality of inverter circuits, A plurality of isolation transformers each having a secondary winding connected in series, a resonance circuit having one end connected to a secondary winding of each of the plurality of isolation transformers connected in series and the other end connected to a load, and an inverter circuit A control circuit for controlling, and among the plurality of inverter circuits, the number of inverter circuits to be operated is changed to control the voltage applied to the load, and the load is a discharge electrode that emits laser light. In some cases, the switching electrode can reduce switching loss when the laser is not oscillating.
実施の形態２．
　実施の形態１に示した電源装置では、インバータ群２２を構成する複数のインバータ回路２３のうちオンとするインバータ回路２３の数を変化させることにより、負荷に出力する出力電圧を制御していたが、実施の形態２に示す電源装置では、オンとするインバータ回路２３の数を変化させることに加え、オンとするインバータ回路の動作位相をずらすことにより負荷に出力する出力電圧を制御する。 Embodiment 2. FIG.
In the power supply device shown in the first embodiment, the output voltage output to the load is controlled by changing the number of inverter circuits 23 to be turned on among the plurality of inverter circuits 23 constituting the inverter group 22. In the power supply device shown in the second embodiment, in addition to changing the number of inverter circuits 23 to be turned on, the output voltage output to the load is controlled by shifting the operation phase of the inverter circuit to be turned on.
　実施の形態２に示す電源装置は、実施の形態１において述べた図１に示す電源装置と同様の構成をしており、説明を省略する。 The power supply device shown in the second embodiment has the same configuration as the power supply device shown in FIG. 1 described in the first embodiment, and a description thereof will be omitted.
　次に、動作について説明する。実施の形態１に示す電源装置では、第１動作モードおよび第２動作モードにおいて、オンとするインバータ回路２３の出力電圧が同相となるように複数のインバータ回路２３を制御したが、実施の形態２に示す電源装置では、オンとなるインバータ回路２３の出力電圧の位相を、制御回路２７によりずらして動作させて調整し、放電電極３への印加電圧の可変範囲を広げる。 Next, the operation will be described. In the power supply device shown in the first embodiment, the plurality of inverter circuits 23 are controlled so that the output voltages of the inverter circuits 23 to be turned on are in phase in the first operation mode and the second operation mode. In the power supply device shown in FIG. 2, the phase of the output voltage of the inverter circuit 23 that is turned on is adjusted by shifting it with the control circuit 27, and the variable range of the voltage applied to the discharge electrode 3 is widened.
　図９に、インバータの位相をずらすと放電電極の印加電圧が下がり、調整できることを示す。図９（ａ）にオンとするインバータ回路２３（ＩＮＶ１～３）間の位相ずれを大きくした場合、図９（ａ）にオンとするインバータ回路２３（ＩＮＶ１～３）間の位相ずれを小さくした場合のインバータ合計出力電圧を示す。図９（ａ）（ｂ）に示すように、オンとする複数のインバータ回路２３の出力電圧の位相を大きくすることにより、出力電圧を低くすることができ、複数のインバータ回路２３の出力電圧の位相をずらすことにより、インバータ回路から出力される合計出力電圧を調整することができる。すなわち、各インバータ回路２３の位相調整により、放電電極３への印加電圧可変範囲が広くなるもしくは微調整が可能となる。 Fig. 9 shows that when the phase of the inverter is shifted, the applied voltage of the discharge electrode decreases and can be adjusted. When the phase shift between the ON inverter circuits 23 (INV1 to 3) is increased in FIG. 9A, the phase shift between the ON inverter circuits 23 (INV1 to 3) is reduced in FIG. 9A. Shows the total output voltage of the inverter. As shown in FIGS. 9A and 9B, the output voltage can be lowered by increasing the phase of the output voltage of the plurality of inverter circuits 23 to be turned on, and the output voltage of the plurality of inverter circuits 23 can be reduced. By shifting the phase, the total output voltage output from the inverter circuit can be adjusted. That is, by adjusting the phase of each inverter circuit 23, the variable range of the applied voltage to the discharge electrode 3 can be widened or finely adjusted.
　実施の形態２に示す電源装置では、上述のような構成及び動作であるため、実施の形態１に示す場合と同様に負荷がレーザ光を発光する放電電極である場合、放電電極がレーザ非発振時におけるスイッチング損失を低減させることができる。さらに、オンとする複数のインバータ回路の位相調整を行うことにより、放電電極への印加電圧の可変範囲が広くなる、もしくは印加電圧の微調整が可能となるという効果が得られる。 Since the power supply device shown in Embodiment 2 has the above-described configuration and operation, when the load is a discharge electrode that emits laser light as in the case of Embodiment 1, the discharge electrode is not laser-oscillated. Switching loss at the time can be reduced. Further, by adjusting the phase of the plurality of inverter circuits that are turned on, it is possible to obtain an effect that the variable range of the applied voltage to the discharge electrode is widened or that the applied voltage can be finely adjusted.
１　交流電源、２　電源装置、２０　ＡＣ／ＤＣ変換器、２１　リンクコンデンサ、２２　インバータ群、２３－１～ｎ　インバータ回路、２４　トランス群、２５－１～ｎ　トランス、２６ａ　共振コイル、２６ｂ　共振コイル、２７　制御回路、２８　制御信号、３　放電電極 1 AC power supply, 2 power supply device, 20 AC / DC converter, 21 link capacitor, 22 inverter group, 23-1 to n inverter circuit, 24 transformer group, 25-1 to n transformer, 26a resonance coil, 26b resonance coil, 27 control circuit, 28 control signal, 3 discharge electrode

Claims (9)

  1. 　交流電源に接続され、前記交流電源から入力される交流電圧を直流電圧に変換するＡＣ／ＤＣ変換部と、
    　それぞれ前記ＡＣ／ＤＣ変換部に対して並列に接続され、前記ＡＣ／ＤＣ変換部により変換された直流電圧を交流電圧に変換する複数のインバータ回路と、
    　１次巻線が前記複数のインバータ回路に接続され、２次巻線が互いに直列接続された複数のトランスと、
    　直列接続された前記複数のトランスの２次巻線に一端が接続され、他端が負荷に接続された共振回路と、
    　前記複数のインバータ回路を制御する制御回路と、
    　を備え、
    　前記制御回路は、前記複数のインバータ回路をオンとして前記負荷に電圧を印加する第１動作モードと、前記複数のインバータ回路の一部であって、前記第１動作モードにおいてオンとするインバータ回路の数より少ないインバータ回路をオンとする第２動作モードを用いて制御すること、
    　を特徴とする電源装置。     An AC / DC converter that is connected to an AC power source and converts an AC voltage input from the AC power source into a DC voltage;
    A plurality of inverter circuits each connected in parallel to the AC / DC converter and converting the DC voltage converted by the AC / DC converter into an AC voltage;
    A plurality of transformers in which a primary winding is connected to the plurality of inverter circuits, and secondary windings are connected in series;
    A resonant circuit having one end connected to the secondary winding of the plurality of transformers connected in series and the other end connected to a load;
    A control circuit for controlling the plurality of inverter circuits;
    With
    The control circuit includes: a first operation mode in which the plurality of inverter circuits are turned on to apply a voltage to the load; and a part of the plurality of inverter circuits that is turned on in the first operation mode. Controlling using a second operating mode that turns on fewer inverter circuits,
    A power supply characterized by.
  2. 　前記負荷は、レーザ発振可能な放電電極であり、
    　前記放電電極は、前記第１動作モードではレーザ発振状態であり、前記第２動作モードでは前記放電電極はレーザ非発振かつ放電維持状態であること、
    　を特徴とする請求項１に記載の電源装置。     The load is a discharge electrode capable of lasing,
    The discharge electrode is in a laser oscillation state in the first operation mode, and in the second operation mode, the discharge electrode is in a laser non-oscillation and discharge maintenance state;
    The power supply device according to claim 1.
  3. 　前記制御回路は、前記第１動作モードにおいて、前記複数のインバータ回路をオンとする時間を制御することにより、前記放電電極からのレーザ出力を制御すること、
    　を特徴とする請求項２に記載の電源装置。     The control circuit controls a laser output from the discharge electrode by controlling a time during which the plurality of inverter circuits are turned on in the first operation mode;
    The power supply device according to claim 2.
  4. 　前記制御回路は、前記第２動作モードから前記第１動作モードに移行する場合に、前記第２動作モードにおいてオフとなっている前記インバータ回路に共振電流を流し、前記オフとなっているインバータ回路が有するスイッチング素子に逆並列に接続されたダイオードを共振電流が流れている状態で当該スイッチング素子をオンすること、
    　を特徴とする請求項１～３のいずれか１項に記載の電源装置。     When the control circuit shifts from the second operation mode to the first operation mode, the control circuit supplies a resonance current to the inverter circuit that is off in the second operation mode, and the inverter circuit is off. Turning on the switching element in a state in which a resonance current flows through a diode connected in reverse parallel to the switching element of
    The power supply device according to any one of claims 1 to 3, wherein:
  5. 　前記制御回路は、前記第２動作モードにおいて、オフとなっている前記インバータ回路に共振電流を流し、前記負荷から前記オフとなっているインバータ回路を介して電力回生すること、
    　を特徴とする請求項１～４のいずれか１項に記載の電源装置。     In the second operation mode, the control circuit causes a resonance current to flow through the inverter circuit that is turned off, and power is regenerated from the load through the inverter circuit that is turned off.
    The power supply device according to any one of claims 1 to 4, wherein:
  6. 　前記制御回路は、前記第１動作モードと前記第２動作モードを繰り返す場合に、前記第２動作モードにおいて、前回の第２動作モードにおいてオンとした前記インバータ回路と異なるインバータ回路をオンとすること、
    　を特徴とした請求項１～５のいずれか１項に記載の電源装置。     When the control circuit repeats the first operation mode and the second operation mode, the control circuit turns on an inverter circuit different from the inverter circuit turned on in the previous second operation mode in the second operation mode. ,
    The power supply device according to any one of claims 1 to 5, wherein:
  7. 　前記複数のトランスは、前記直列接続された２次巻線の中点が対接地されていること、
    　を特徴とする請求項１～６のいずれか１項に記載の電源装置。     In the plurality of transformers, a middle point of the series-connected secondary windings is grounded,
    The power supply device according to any one of claims 1 to 6, wherein:
  8. 　前記制御回路は、前記第２動作モードにおいて、接地基準で対象となるように前記インバータ回路をオンとすること、
    　を特徴とする請求項７に記載の電源装置。     The control circuit, in the second operation mode, to turn on the inverter circuit so as to be a target on the ground reference;
    The power supply device according to claim 7.
  9. 　前記制御回路は、前記第１動作モードまたは前記第２動作モードにおいてオンとするインバータの出力電圧の位相を制御することにより前記負荷に出力する電圧を制御すること、
    　を特徴とする請求項１～８のいずれか１項に記載の電源装置。     The control circuit controls a voltage output to the load by controlling a phase of an output voltage of an inverter that is turned on in the first operation mode or the second operation mode;
    The power supply device according to any one of claims 1 to 8, wherein:
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01134398U (en) * 1988-03-08 1989-09-13
JPH0870581A (en) * 1994-08-30 1996-03-12 Railway Technical Res Inst High-output inverter device
JP2003125586A (en) * 2001-10-15 2003-04-25 Amada Eng Center Co Ltd Power unit for plasma generation
JP2008005575A (en) * 2006-06-20 2008-01-10 Sanken Electric Co Ltd Dc/ac inverter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01134398U (en) * 1988-03-08 1989-09-13
JPH0870581A (en) * 1994-08-30 1996-03-12 Railway Technical Res Inst High-output inverter device
JP2003125586A (en) * 2001-10-15 2003-04-25 Amada Eng Center Co Ltd Power unit for plasma generation
JP2008005575A (en) * 2006-06-20 2008-01-10 Sanken Electric Co Ltd Dc/ac inverter

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