Power supply device and laser device

Abstract

The present invention provides a power supply device that can make a load operate stably from the moment the load starts to operate. The charging power supply performs a charging operation to make the voltage between the terminals of the capacitor close to the voltage target value in synchronization with the operation of the load that performs intermittent operation. The charging power supply has a function of switching between a first operation mode and a second operation mode, wherein in the first operation mode, if the voltage between the terminals of the capacitor deviates from a first voltage allowable range, an auxiliary charging and discharging operation is performed to make the voltage between the terminals of the capacitor close to the voltage target value, and in the second operation mode, if the voltage between the terminals of the capacitor deviates from a second voltage allowable range that is narrower than the first voltage allowable range, an auxiliary charging and discharging operation is performed.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2019-231735 filed on December 23, 2019. The entire contents of the Japanese patent application are incorporated herein by reference. Technical Field

[0002] The invention relates to a power supply device and a laser device. Background Art

[0003] As an industrial processing tool, a laser processing device is widely used (for example, Patent Document 1). The laser processing device includes, for example, a pulsed laser oscillator such as a carbon dioxide laser oscillator, a high-frequency power supply, and a power supply device. The power supply device supplies direct current to the high-frequency power supply, and the high-frequency power supply converts the direct current into alternating current and supplies it to the discharge electrode of the laser oscillator.

[0004] The power supply device has a capacitor, to which a load such as a high-frequency power supply is connected. DC power is stored in the capacitor, and the capacitor supplies DC power to the load. If the load consumes power, the voltage between the capacitor terminals will drop. The power supply device performs feedback control to bring the voltage between the capacitor terminals (the output voltage of the power supply device) close to the target value.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-254186

[0006] When the load is in standby mode (i.e., the load consumes almost no power), the output voltage will gradually decrease due to natural discharge or a small amount of power consumption during standby. If the output voltage decreases and deviates from the voltage tolerance range, feedback control is performed to bring the output voltage closer to the target value.

[0007] If the load starts to operate when the output voltage is close to the lower limit of the voltage tolerance range, the output voltage of the power supply device may drop due to the operation of the load and deviate significantly from the voltage tolerance range. If the output voltage deviates significantly from the voltage tolerance range, the power supplied to the load will decrease, and the stability of the load operation will decrease. Summary of the invention

[0008] An object of the present invention is to provide a power supply device that can stably operate a load from the moment the load starts operating. Another object of the present invention is to provide a laser device equipped with the power supply device.

[0009] According to one aspect of the present invention, there is provided a power supply device having a charging power supply that performs a charging operation in synchronization with the operation of the intermittently operating load so as to bring the inter-terminal voltage of a capacitor connected to the intermittently operating load close to a voltage target value.

[0010] The charging power supply has a function of switching between a first action mode and a second action mode, wherein, in the first action mode, if the voltage between the terminals of the capacitor deviates from a first voltage allowable range, an auxiliary charge and discharge action is performed to make the voltage between the terminals of the capacitor close to the voltage target value, and in the second action mode, if the voltage between the terminals of the capacitor deviates from a second voltage allowable range narrower than the first voltage allowable range, the auxiliary charge and discharge action is performed.

[0011] According to another aspect of the present invention, there is provided a power supply device having:

[0012] Capacitors, connected to loads that perform intermittent operation; and

[0013] a charging power supply that performs a charging operation to bring the voltage between the terminals of the capacitor close to a voltage target value in synchronization with the operation of the load,

[0014] The charging power supply includes a switching converter having a low-side switching element, and the charging operation is performed by switching the low-side switching element, thereby supplying a current corresponding to the on-time of the low-side switching element to the capacitor.

[0015] The charging power supply has a function of determining an on-time of the low-side switching element according to a deviation of the voltage between the terminals of the capacitor from the voltage target value and an actual value of the on-time of the low-side switching element when the load is operating.

[0016] According to another aspect of the present invention, there is provided a laser device having:

[0017] A laser oscillator having a discharge electrode and performing pulse oscillation;

[0018] a high frequency power supply that converts direct current into alternating current in synchronization with a trigger signal and supplies the alternating current to the discharge electrode in a pulse form; and

[0019] A power supply device, wherein the high frequency power supply supplies direct current,

[0020] The power supply device comprises:

[0021] a capacitor for storing direct current supplied to the high frequency power source; and

[0022] a charging power supply that performs a charging operation in synchronization with the trigger signal so that the voltage between the terminals of the capacitor approaches a voltage target value,

[0023] The charging power supply has a function of switching between a first action mode and a second action mode, wherein, in the first action mode, if the voltage between the terminals of the capacitor deviates from a first voltage allowable range, an auxiliary charge and discharge action is performed to make the voltage between the terminals of the capacitor close to the voltage target value, and in the second action mode, if the voltage between the terminals of the capacitor deviates from a second voltage allowable range narrower than the first voltage allowable range, the auxiliary charge and discharge action is performed.

[0024] According to another aspect of the present invention, there is provided a laser device having:

[0025] A laser oscillator having a discharge electrode and performing pulse oscillation;

[0026] A high frequency power supply supplies alternating current in pulse form to the discharge electrode in synchronization with a trigger signal; and

[0027] a power supply device for supplying direct current to the high frequency power supply,

[0028] The power supply device comprises:

[0029] a capacitor for storing direct current supplied to the high frequency power source; and

[0030] a charging power supply that performs a charging operation in synchronization with the trigger signal so that the voltage between the terminals of the capacitor approaches a voltage target value,

[0031] The charging power supply includes a switching converter having a low-side switching element, and the charging operation is performed by switching the low-side switching element, thereby supplying a current corresponding to the on-time of the low-side switching element to the capacitor.

[0032] The charging power supply determines the on-time of the low-side switching element based on a deviation of the voltage between the terminals of the capacitor from the voltage target value and an actual value of the on-time of the low-side switching element during the charging operation.

[0033] When the second operation mode is switched to the first operation mode, the voltage between the capacitor terminals is within the relatively narrow second allowable range. Compared with the case where the voltage between the capacitor terminals fluctuates within the wider first voltage allowable range, the load can be operated stably from the start of the first operation mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a block diagram of a power supply device that represents a part of the power supply device according to the embodiment and a block diagram of a load of the power supply device as an equivalent circuit.

[0035] Figure 2This is a graph showing the temporal changes of a trigger signal, the on / off state of a low-side switching element, a current flowing through a reactor, a current flowing through a capacitor, and a voltage between the terminals of the capacitor.

[0036] Figure 3 is a block diagram showing the feedback control function of the converter controller.

[0037] Figure 4 It is a graph showing the temporal changes of the trigger signal Trg, the output voltage VC, the on / off state of the low-side switching element Q1 and the current IC flowing through the capacitor when the output voltage VC after charging under the control of the main charging control unit is lower than the lower limit value of the first voltage allowable range Var1.

[0038] Figure 5 It is a graph showing the time-dependent changes of the trigger signal Trg, the output voltage VC, the on / off state of the low-side switch element Q1, the on / off state of the high-side switch element Q2, and the current IC flowing through the capacitor when the output voltage VC exceeds the upper limit value of the first voltage tolerance range Var1 after charging based on the control of the main charging control unit.

[0039] Figure 6 (A) is a graph showing the change in output voltage VC before and after the load switches from the standby state to the operating state. Figure 6 (B) is a graph showing changes in the output voltage VC in the period before and after the load switches from the standby state to the operating state when the feedback control method according to the comparative example is applied.

[0040] Figure 7 This is a block diagram showing a feedback control function of a converter controller mounted on a power supply device according to another embodiment.

[0041] Figure 8 : is a graph showing a table for storing the on-time final value TonL stored in the on-time setting unit.

[0042] Fig. 9 (A) is a diagram showing an example of the change over time of the load operating conditions and the on-time setting value TonS input to the adder. Fig. 9 (B) in the middle is a diagram showing an example of temporal changes in the operating conditions of the load and the on-time setting value TonS input to the adder when the operating conditions are switched between ID00 and ID01.

[0043] Fig.10 is a block diagram of a laser device according to still another embodiment.

[0044] Fig.11This is a diagram showing an example of an image displayed on an output device.

[0045] Fig.12 This is a diagram showing an example of an image in which the current on-time final value TonL is displayed on an output device.

[0046] In the figure: 10-power supply device, 20-charging power supply, 25-switching converter, 30-converter controller, 31-feedback control unit, 311-subtractor, 313-main charging control unit, 314-auxiliary charging and discharging control unit, 315-adder, 316-on time setting unit, 317-effective control unit selection unit, 318-action mode switching unit, 32-pulse width modulator, 35-AD converter, 40-capacitor, 50-load, 51-high frequency power supply, 52-laser oscillator, 53-discharge electrode, 55-optical system, 56-movable workbench, 58-processing object, 60-upper controller, 61-input device, 62-output device, 70-external power supply, D1, D2-freewheeling diodes, L-reactor, Q1-low-side switching element, Q2-high-side switching element. DETAILED DESCRIPTION

[0047] refer to Figure 1 to Figure 6 , a power supply device based on an embodiment is described.

[0048] Figure 1 1 is a block diagram of a power supply device and a load of the power supply device, which are represented by an equivalent circuit. The power supply device 10 includes a charging power supply 20 and a capacitor 40. A DC power of a voltage Vin from an external power supply 70 is supplied to the charging power supply 20. The charging power supply 20 boosts the voltage Vin to charge the capacitor 40. The voltage between the terminals of the capacitor 40 becomes the output voltage VC of the power supply device 10.

[0049] A load 50 is connected to the capacitor 40. The load 50 performs intermittent operation according to a trigger signal Trg from a host controller 60. The load 50 includes a high-frequency power supply 51 and a laser oscillator 52. The laser oscillator 52 is, for example, a gas laser oscillator such as a carbon dioxide laser oscillator, and has a pair of discharge electrodes 53. The high-frequency power supply 51 converts the direct current supplied from the power supply device 10 into alternating current according to the trigger signal Trg from the host controller 60, and supplies the alternating current to the discharge electrode 53 of the laser oscillator 52. As the high-frequency power supply 51, for example, an inverter is used. The capacitor 40 can be understood as a DC power supply such as an electric storage device that supplies power to the load 50 as a single unit. Such a capacitor is sometimes referred to as a capacitor bank.

[0050] The charging power supply 20 includes a switching converter 25 and a converter controller 30. The capacitor 40 has a large electrostatic capacitance so that the output voltage VC does not drop below the lower limit of the allowable range during the discharge process of one operation cycle of the load 50. The charging power supply 20 performs a charging operation for charging the capacitor 40 in synchronization with the trigger signal Trg.

[0051] The switching converter 25 has a topological structure of a boost converter. Specifically, the switching converter 25 includes a low-side switching element Q1, a high-side switching element Q2, freewheeling diodes D1, D2, and a reactor L. As the low-side switching element Q1 and the high-side switching element Q2, a field effect transistor (FET), a bipolar transistor, an insulated gate bipolar transistor (IGBT), etc. can be used. The converter controller 30 controls the on / off of the low-side switching element Q1 and the high-side switching element Q2.

[0052] A closed circuit is formed by the external power supply 70, the reactor L and the low-side switching element Q1. A freewheeling diode D1 is connected to the low-side switching element Q1. In addition, another closed circuit is formed by the external power supply 70, the reactor L, the high-side switching element Q2 and the capacitor 40. A freewheeling diode D2 is connected to the high-side switching element Q2.

[0053] If the low-side switch element Q1 is turned on and then turned off, the voltage Vin is stepped up to charge the capacitor 40, and the output voltage VC increases. The control of turning the switch element on and then turning it off is called a switching operation. If the high-side switch element Q2 performs a switching operation, power is returned from the capacitor 40 to the external power supply 70, and the output voltage VC of the capacitor 40 decreases.

[0054] The host controller 60 sends a trigger signal Trg to the converter controller 30 and the high-frequency power supply 51. The high-frequency power supply 51 operates intermittently at a repetition frequency of about several kHz and a duty ratio of about 5% in synchronization with the trigger signal Trg. The capacitor 40 is discharged by the operation of the high-frequency power supply 51, thereby supplying AC power to the discharge electrode 53. As a result, a discharge is generated in the space between the discharge electrodes 53, and a one-shot pulse laser beam is output. For example, the trigger signal Trg takes two values, a high level and a low level. During the period when the trigger signal Trg is at a high level, the high-frequency power supply 51 supplies AC power to the discharge electrode 53.

[0055] The converter controller 30 operates the switching converter 25 in synchronization with the trigger signal Trg to charge the capacitor 40. The charge amount at this time is set to be equivalent to the discharge amount of the capacitor 40 based on the trigger signal Trg once.

[0056] Next, refer to Figure 2, the operation of the switching converter 25 when the low-side switching element Q1 performs a switching operation corresponding to the primary trigger signal Trg will be described.

[0057] Figure 2 It is a graph showing the time-dependent changes of the trigger signal Trg, the on / off state of the low-side switch element Q1, the current IL flowing through the reactor L, the current IC flowing through the capacitor 40, and the output voltage VC. The trigger signal Trg rises at time t0 and falls at the moment (time t1) after the excitation period Pex has passed. At the moment (time t0) when the trigger signal Trg rises, the output voltage VC is within the voltage tolerance range Var.

[0058] When the trigger signal Trg rises, the load 50 operates during the excitation period Pex. The operation of the load 50 discharges the charge of the capacitor 40, and the output voltage VC decreases by a decrease width ΔV. Since the capacitance of the capacitor 40 is sufficiently larger than the discharge amount, the output voltage VC does not decrease below the lower limit of the voltage allowable range Var.

[0059] The converter controller 30 switches the low-side switch element Q1 in synchronization with the trigger signal Trg. For example, the converter controller 30 turns the low-side switch element Q1 into the on state at the same time as the rise of the trigger signal Trg. Then, the converter controller 30 turns the low-side switch element Q1 back to the off state at the moment (time t2) when the on-time Ton1 has passed since the on-time. The on-time Ton1 is longer than the excitation period Pex.

[0060] During the period when the low-side switch element Q1 is in the on state, the current IL flowing through the reactor L increases. At this time, the current IL flows to the low-side switch element Q1, so the current IC flowing into the capacitor 40 is zero. Therefore, during the period from the time when the trigger signal Trg falls (time t1) to the time when the low-side switch element Q1 is in the off state (time t2), the output voltage VC of the capacitor 40 is substantially constant.

[0061] When the low-side switch element Q1 is turned off at time t2, the current IL flowing through the reactor L starts to flow to the capacitor 40 via the freewheeling diode D2. As a result, the current IC flowing through the capacitor 40 increases, and the output voltage VC starts to increase. The current IL flowing through the reactor L and the current IC flowing through the capacitor 40 decrease with the passage of time and become substantially zero at time t3.

[0062] The rise of the output voltage VC from time t2 to time t3 depends on the on-time Ton1. The on-time Ton1 is set so that the rise of the output voltage VC is substantially equal to the drop ΔV of the output voltage of the capacitor 40 based on one operation cycle of the load 50. Therefore, the output voltage VC substantially returns to the original level at time t3.

[0063] If the on-time Ton1 is set to a fixed value, the increase amplitude of the output voltage VC may not be equal to the decrease amplitude ΔV due to changes in the load or the input voltage. If the state in which the increase amplitude of the output voltage VC is not equal to the decrease amplitude ΔV continues, the output voltage VC may deviate from the voltage tolerance range Var. In the present embodiment, the converter controller 30 performs feedback control to make the output voltage VC close to the voltage target value Vref.

[0064] Figure 3 2 is a block diagram showing the feedback control function of the converter controller 30. The main part of the feedback control function of the converter controller 30 may be implemented by a combination of a software program and a processor that executes the software program, or may be implemented by hardware.

[0065] The converter controller 30 includes a feedback control unit 31 and a pulse width modulator 32. The feedback control unit 31 includes a main charge control unit 313, an auxiliary charge and discharge control unit 314, an operation mode switching unit 318, and an effective control unit selection unit 317. The effective control unit selection unit 317 enables one of the main charge control unit 313 and the auxiliary charge and discharge control unit 314. The conditions for switching from the state in which the main charge control unit 313 is effective to the state in which the auxiliary charge and discharge control unit 314 is effective vary depending on the operation mode set by the operation mode switching unit 318. The control unit that is set to be effective performs feedback control.

[0066] First, the control when the main charging control unit 313 is effective is described. The output voltage VC after charging in a certain operation cycle is converted into a digital value by the AD converter 35. The subtractor 311 subtracts the output voltage VC from the voltage target value Vref to generate the deviation Verr of the output voltage VC relative to the voltage target value Vref. The main charging control unit 313 generates the on-time correction value ΔTon1 of the next operation cycle so that the deviation Verr is close to zero. The main charging control unit 313 adopts PID control or PI control.

[0067] Adder 315 adds on-time fixed value TonF and on-time correction value ΔTon1 to determine on-time Ton1 of the next operation cycle. Pulse width modulator 32 controls switching converter 25 according to the determined on-time Ton1. Thus, feedback control is performed to bring output voltage VC close to voltage target value Vref.

[0068] Next, the control when the auxiliary charge and discharge control unit 314 is enabled will be described. Figure 2 ), the effective control unit selection unit 317 makes the auxiliary charge and discharge control unit 314 effective. The auxiliary charge and discharge control unit 314 adopts P control, PI control or PID control. The auxiliary charge and discharge control unit 314 generates an on-time Ton2 that makes the deviation Verr close to zero. The pulse width modulator 32 controls the switching converter 25 according to the on-time Ton2. The output voltage VC deviates from the voltage allowable range Var( Figure 2 ) when the auxiliary charge and discharge control unit 314 is enabled to control the switching converter 25 is called an auxiliary charge and discharge operation.

[0069] The operation mode switching unit 318 switches the charging power source 20 ( Figure 1 ). During the period when the host controller 60 causes the load 50 to intermittently operate (hereinafter referred to as in operation), the operation mode of the charging power source 20 is set to the first operation mode. When the host controller 60 does not operate the load 50 and the load 50 is in a standby state, the operation mode of the charging power source 20 is set to the second operation mode. In this way, the operation mode switching unit 318 switches between the first operation mode and the second operation mode.

[0070] When the operation mode of the charging power source 20 is the first operation mode or the second operation mode, the voltage tolerance range Var ( Figure 2 The voltage allowable range in the first operation mode is referred to as the first voltage allowable range Var1, and the voltage allowable range in the second operation mode is referred to as the second voltage allowable range Var2. Information determining the size of the first voltage allowable range Var1 and the second voltage allowable range Var2 is stored in the operation mode switching unit 318.

[0071] Next, refer to Figure 4 and Figure 5 , the control when the operation mode of the charging power source 20 is the first operation mode is described. When the operation mode of the charging power source 20 is the first operation mode, the upper controller 60 intermittently supplies the high frequency power source 51 ( Figure 1 ) and converter controller 30( Figure 1 ) supplies a trigger signal Trg, thereby causing the load 50 to operate.

[0072] Figure 4It is a graph showing the time-dependent changes of the trigger signal Trg, the output voltage VC, the on / off state of the low-side switch element Q1, and the current IC flowing through the capacitor 40 when the output voltage VC after charging based on the control of the main charging control unit 313 is lower than the lower limit value of the first voltage tolerance range Var1. At time t0, the trigger signal Trg rises and the low-side switch element Q1 becomes the on state. At time t1, the trigger signal Trg falls, and at time t2, the low-side switch element Q1 becomes the off state. The on time Ton1 of the low-side switch element Q1 is calculated by adjusting the on time Ton1 of the low-side switch element Q1 by the main charging control unit 313 ( Figure 1 ) is determined by adding the on-time correction value ΔTon1 generated by the on-time correction value ΔTon1 and the on-time fixed value TonF.

[0073] If the low-side switch element Q1 is turned off, the current IC charging the capacitor 40 increases, and the output voltage VC starts to increase. At time t3 when the current IC charging the capacitor 40 becomes substantially zero, the output voltage VC does not reach the lower limit of the first voltage tolerance range Var1. This situation may occur, for example, in the following case, that is, the output voltage VC at the time t0 when the trigger signal Trg rises is close to the lower limit of the first voltage tolerance range Var1, and the load 50 ( Figure 1 )The power consumption in one action cycle is greater than the estimated value.

[0074] If the effective control unit selection unit 317 ( Figure 3 ) detects that the output voltage VC is lower than the lower limit value of the first voltage tolerance range Var1, the auxiliary charge and discharge control unit 314 becomes effective. Information determining the lower limit value and the upper limit value of the first voltage tolerance range Var1 is sent from the operation mode switching unit 318 to the effective control unit selection unit 317. The auxiliary charge and discharge control unit 314 generates an on-time Ton2 that makes the output voltage VC close to the voltage target value Vref.

[0075] The pulse width modulator 32 turns on the low-side switch element Q1 for the on-time Ton2. After the time t4 when the low-side switch element Q1 is switched from the on-state to the off-state, the current IC for charging the capacitor 40 flows, and the output voltage VC rises. The rise of the output voltage VC depends on the on-time Ton2. Since the on-time Ton2 is determined so that the deviation Verr of the output voltage VC from the voltage target value Vref is close to zero, the output voltage VC is close to the voltage target value Vref. As a result, the output voltage VC falls within the first voltage allowable range Var1.

[0076] Figure 5It is a graph showing the time-dependent changes of the trigger signal Trg, the output voltage VC, the on / off state of the low-side switch element Q1, the on / off state of the high-side switch element Q2, and the current IC flowing through the capacitor 40 when the output voltage VC after charging exceeds the upper limit value of the first voltage tolerance range Var1 based on the control of the main charging control unit 313. At time t3 when the current IC charging the capacitor 40 after one operation cycle becomes substantially zero, the output voltage VC exceeds the upper limit value of the first voltage tolerance range Var1. This situation may occur, for example, in the following situation, that is, the output voltage VC at the time t0 when the trigger signal Trg rises is close to the upper limit value of the first voltage tolerance range Var1, and the load 50( Figure 1 )The power consumption in one action cycle is less than the estimated value.

[0077] If the effective control unit selection unit 317 ( Figure 3 ) detects that the output voltage VC exceeds the upper limit of the first voltage tolerance range Var1, the auxiliary charge and discharge control unit 314 becomes effective. The auxiliary charge and discharge control unit 314 generates an on-time Ton2 so that the output voltage VC is close to the voltage target value Vref. If the output voltage VC at the current moment is higher than the voltage target value Vref, a negative value is generated as the on-time Ton2.

[0078] When the on-time Ton2 is negative, the pulse width modulator 32 turns on the high-side switch element Q2 for a time corresponding to the absolute value of the on-time Ton2. During the on-time of the high-side switch element Q2, the current IC that discharges the capacitor 40 flows, and the output voltage VC decreases. The reduction range of the output voltage VC depends on the absolute value of the on-time Ton2. Since the on-time Ton2 is determined so that the deviation Verr of the output voltage VC from the voltage target value Vref is close to zero, the output voltage VC is close to the voltage target value Vref. As a result, the output voltage VC falls within the first voltage tolerance range Var1.

[0079] like Figure 4 and Figure 5 As shown, when the operation mode of the charging power source 20 is the first operation mode, if the output voltage VC deviates from the first allowable voltage range Var1, feedback control is performed to make the output voltage VC fall within the first allowable voltage range Var1.

[0080] Next, refer to Figure 6 In (A), feedback control when the operation mode of the charging power source 20 is the second operation mode is described.

[0081] Figure 6(A) is a graph showing changes in output voltage VC before and after the load 50 switches from the standby state to the operating state (intermittent operation state). The second voltage allowable range Var2 is narrower than the first voltage allowable range Var1 and is included in the first voltage allowable range Var1.

[0082] When the operation mode of the charging power source 20 is the second operation mode, the load 50 does not perform intermittent operation, but the output voltage VC of the capacitor 40 gradually decreases due to various reasons. For example, the output voltage VC decreases due to the natural discharge of the capacitor 40. Figure 1 ) is not outputting a pulse laser beam, sometimes the discharge electrode 53 ( Figure 1 ) supplies high-frequency power of a short duration to the extent that laser oscillation is not generated. The pulse of high-frequency power of a short duration to the extent that laser oscillation is not generated in this way is called a flash pulse. By supplying the flash pulse to the discharge electrode 53, the output voltage VC decreases.

[0083] When the output voltage VC becomes smaller than the lower limit value of the second voltage tolerance range Var2 while the operation mode of the charging power source 20 is the second operation mode, the effective control unit selection unit 317 ( Figure 3 ) makes the auxiliary charge and discharge control unit 314 effective. As a result, the capacitor 40 is turned on according to the on time Ton2 ( Figure 3 ) is charged, and the output voltage VC rises and approaches the voltage target value Vref. As a result, while the load 50 is in the standby state, the output voltage VC is controlled to fall substantially within the second voltage allowable range Var2.

[0084] When load 50 enters the operating state, charging power source 20 switches from the second operation mode to the first operation mode. Thus, output voltage VC is controlled to fall within first allowable voltage range Var1.

[0085] Next, compare Figure 6 The excellent effects of this embodiment will be described with reference to the comparative example shown in (B).

[0086] Figure 6 (B) is a graph showing the change in output voltage VC before and after the load 50 switches from the standby state to the operating state when the feedback control method based on the comparative example is applied. In the comparative example, the voltage tolerance range in the standby state is the same as the voltage tolerance range in the operating state. For example, the voltage tolerance range in the comparative example is set to Figure 6 The first voltage tolerance range Var1 of (A) is the same.

[0087] When the load 50 is in the standby state, the output voltage VC is feedback-controlled to fall within the first voltage tolerance range Var1. If the load 50 is in the operating state at the moment when the output voltage VC is near the lower limit of the first voltage tolerance range Var1, the output voltage VC will greatly deviate from the first voltage tolerance range Var1 in the first operation cycle. If the output voltage VC greatly deviates from the first voltage tolerance range Var1, the AC power supplied to the load 50 will decrease. Therefore, the output voltage VC from the laser oscillator 52 ( Figure 1 ) will drop below the target value in the energy of each pulse of the pulsed laser beam outputted by the laser processing unit. As a result, the quality of laser processing will be reduced.

[0088] In contrast, Figure 6 In the embodiment shown in (A), the output voltage VC in the standby state is feedback-controlled to fall within the second voltage tolerance range Var2 which is narrower than the first voltage tolerance range Var1. Therefore, the deviation of the output voltage VC at the time of the first action cycle after switching to the operation state becomes smaller. As a result, stable AC power can be supplied to the load 50 from the first action cycle. Thus, the degradation of the laser processing quality can be suppressed.

[0089] In order to obtain a sufficient effect of suppressing the deviation of the output voltage VC in the first operation cycle after the load 50 becomes the operating state, the size of the second voltage allowable range Var2 is preferably set to be less than 1 / 5 of the size of the first voltage allowable range Var1. In addition, in order to make the output voltage VC dropped in the first operation cycle fall within the first voltage allowable range Var1, the lower limit value of the second voltage allowable range Var2 is preferably set to be greater than the median value of the first voltage allowable range Var1.

[0090] The charging power source 20 according to the above embodiment can also be used for Figure 1 The charging power supply 20 according to the above embodiment can also be applied to a charging power supply for charging a capacitor connected to an intermittently operating load to supply power to the load.

[0091] Next, refer to Figure 7 to Figure 9 , a power supply device based on another embodiment is described. Figures 1 to 6 The power supply device of the embodiment shown has the same structure as that of the embodiment shown.

[0092] Figure 7 is a block diagram showing the feedback control function of the converter controller 30 mounted on the power supply device of this embodiment. Figure 3In the illustrated embodiment, the parameter input to the adder 315 is the constant on-time fixed value TonF. In contrast, in the present embodiment, the on-time setting value TonS is input to the adder 315 from the on-time setting unit 316 .

[0093] Next, the function of the on-time setting unit 316 is described. The operating condition identification information ID and the trigger signal Trg are input from the host controller 60 to the on-time setting unit 316. The operating condition identification information ID is information for determining the operating condition of the load 50. For example, the laser oscillator 52 ( Figure 1 ) outputs a pulse laser beam according to various operating conditions such as pulse energy and pulse width. These operating conditions are determined by the operating condition identification information ID. If the operating conditions of the load 50 are different, the power consumption in one operating cycle is generally different. Therefore, if the operating conditions are different, the reduction range ΔV ( Figure 2 ) are also different.

[0094] Figure 8 1 is a diagram showing a table for storing the final on-time value TonL stored in the on-time setting unit 316. The final on-time value TonL is stored for each operating condition of the load 50. The on-time setting unit 316 acquires the on-time Ton1 generated in the adder 315 in synchronization with the trigger signal Trg for each operating cycle of the load 50, and stores it as the final on-time value TonL after establishing a correspondence with the operating condition identification information ID at the current moment. That is, the on-time setting unit 316 rewrites the last value of the on-time Ton1 with the value of the last on-time Ton1. Figure 8 The table shows the final value of the on-time TonL.

[0095] When the load 50 switches from the standby state to the operating state, the on-time setting unit 316 changes from Figure 8 The on-time final value TonL corresponding to the operating condition identification information ID at the current moment is read from the table, and the value of the on-time final value TonL is set as the on-time setting value TonS. During the operation under the same operating condition, the on-time setting value TonS is input to the adder 315. When the operating condition is changed or when the standby state is switched to the operating state, the on-time setting value TonS is reset to the value of the on-time final value TonL of the corresponding operating condition.

[0096] Fig. 9 (A) is a diagram showing an example of the change over time of the operating conditions of the load 50 and the on-time setting value TonS input to the adder 315. Fig. 9(A) shows an example in which the operating condition of the load 50 is ID00 and remains unchanged. Figure 1 ) is turned on, firstly, a preheating operation is performed under the operating condition ID00. Then, the load 50 operates under the operating condition ID00 while gradually shortening the period of the standby state.

[0097] In the preheating operation, the value of the on-time Ton1 is set to the on-time final value TonL in each operation cycle (i.e., each time the trigger signal Trg is output). In addition, as the on-time setting value TonS in the preheating operation, for example, Figure 3 The on-time fixed value TonF is shown. At the time when the warm-up operation ends, the final on-time Ton1 value is set to the on-time final value TonL.

[0098] When the load 50 is operated under the operation condition ID00 after the standby state, the on-time final value TonL at the current moment is set as the on-time setting value TonS. While the load 50 is operated under the operation condition ID00, the set on-time setting value TonS is used. And, while the load 50 is operated under the operation condition ID00, the value of the on-time Ton1 is set as the on-time final value TonL for each operation cycle (i.e., each time the trigger signal Trg is output).

[0099] Fig. 9 (B) is a diagram showing an example of the time-dependent change of the operating condition of the load 50 and the on-time setting value TonS input to the adder 315 when the operating condition is switched between ID00 and ID01. After operating under the operating condition ID00, operating under the operating condition ID01, and then operating under the operating condition ID00 again. When switching from the operating condition ID01 to the operating condition ID00, the on-time final value TonL of the operating condition ID00 is set to the on-time setting value TonS.

[0100] When the operation under the operation condition ID01 is started, the on-time Ton1 (ie, the on-time final value TonL) applied last when the operation under the same operation condition ID01 is performed is set as the on-time setting value TonS.

[0101] In this way, when the standby state is shifted to the operating state, the value of the on-time Ton1 applied in the last operating cycle during the period of operating under the same operating conditions as the current operating conditions is set as the on-time setting value TonS.

[0102] Next, Figure 7 to Figure 9 The excellent effects of the illustrated embodiment will be described.

[0103] In the image Figure 3 When the on-time fixed value TonF is used as a parameter input to the adder 315 as in the embodiment shown in the figure, the reduction range ΔV ( Figure 2 ) is used to set the on-time fixed value TonF. The mode in which the on-time fixed value TonF is used as a parameter input to the adder 315 is called the on-time fixed mode. In contrast, the mode in which the on-time setting value TonS is used as a parameter input to the adder 315 is called the on-time variable mode.

[0104] The reduction range ΔV of the output voltage VC in one operation cycle may be greatly deviated from the estimated value due to various factors. As various factors that cause the reduction range ΔV of the output voltage VC to greatly deviate from the estimated value, for example, the external power supply 70 ( Figure 1 ) Changes in the voltage Vin supplied, changes in the excitation conditions of the laser oscillator 52, etc.

[0105] When the decrease width ΔV of the output voltage VC in one operation cycle of the load 50 greatly deviates from the estimated value, Figure 3 The feedback control of changing the on-time correction value ΔTon1 shown in the figure can set the on-time Ton1 to an appropriate value. However, until the on-time Ton1 reaches an appropriate value, the operation cycle of the load 50 must be repeated several times. Until the on-time Ton1 reaches an appropriate value and the output voltage VC becomes stable, the laser oscillator 52 ( Figure 1 ) The pulse energy of the pulsed laser beam outputted by the power supply 10 is unstable. The pulsed laser beam during the period of unstable pulse energy cannot be used for laser processing. Therefore, the actual laser processing must be allowed to wait from the start of the operation of the power supply device 10 and the load 50 until the pulse energy becomes stable.

[0106] In contrast, in this embodiment, Fig. 9 During the preheating operation shown in (A), the actual on-time Ton1 value at the current moment is set as the on-time final value TonL. When the load 50 is operated for actual laser processing, the on-time Ton1 value applied in the last operation cycle in the preheating operation is set as the on-time setting value TonS. Therefore, the load 50 can be operated using an appropriate value as the on-time setting value TonS from the first operation cycle.

[0107] Furthermore, when the operating condition is switched, the value of the on-time Ton1 applied in the final operating cycle when the operation is performed under the same operating condition as the switched operating condition is set as the on-time setting value TonS. Therefore, after the operating condition is changed, the load 50 can be operated using an appropriate value as the on-time setting value TonS.

[0108] Therefore, the pulse energy can be stabilized from the first operation cycle after the warm-up operation and after the operation conditions are switched, thereby enabling laser processing to be performed immediately, thereby achieving an excellent effect of improving the processing capacity of the laser processing device.

[0109] Furthermore, in the present embodiment, while the load 50 is being operated, each time the on-time Ton1 is determined, the on-time final value TonL is updated with the new on-time Ton1 value. Therefore, at the moment when the operation of the load 50 ends, the on-time final value TonL is always set to the latest on-time Ton1 value. Thus, when the operation of the load 50 is restarted under the same operating conditions, the load 50 can be operated using an appropriate value as the on-time setting value TonS.

[0110] Next, Figure 7 to Figure 9 Modifications of the illustrated embodiment will be described.

[0111] exist Figure 7 to Figure 9 In the illustrated embodiment, when the load 50 starts to operate, the final value of the on-time Ton1 applicable when the load 50 operates under the same operating conditions is used as the on-time setting value TonS. The value used as the on-time setting value TonS does not necessarily have to be the final value of the on-time Ton1, and the value of the on-time Ton1 applicable when the load 50 was operated under the same operating conditions in the past may be used as the on-time setting value TonS. In addition, a statistical representative value (for example, an average value, a mode value, a median value, etc.) of a plurality of on-time Ton1 values ​​may be used as the on-time setting value TonS.

[0112] exist Fig. 9 In (A), a standby period is inserted between the warm-up operation period and the operation period under the operating condition ID00, and a standby period is inserted between two operation periods with different operating conditions. However, the standby period may be omitted.

[0113] Next, refer to Figure 10 to Figure 12 , a laser device based on another embodiment is described. Figure 1 to Figure 6 The embodiment shown, Figure 7 to Figure 9 Description of the same structure of the embodiment shown.

[0114] Fig.10The laser device according to this embodiment performs drilling processing on a processing object 58 such as a printed circuit board. The power supply device 10, the high frequency power supply 51, the laser oscillator 52 and the host controller 60 are similar to the structure of FIG. Figure 1 The structure shown in FIG. 1 is the same as that shown in FIG. Various information or operation instructions necessary for the power supply device 10 to operate are input from the input device 61 to the upper controller 60. As the input device 61, for example, a keyboard, a pointing device, a reader of a removable medium, etc. are used. The upper controller 60 outputs various information to the output device 62. As the output device 62, for example, a display is used. As the input device 61 and the output device 62, a touch panel having both functions may also be used.

[0115] A processing object 58 such as a printed circuit board is held on the movable table 56. The pulse laser beam output from the laser oscillator 52 is incident on the processing object 58 through the optical system 55. The optical system 55 includes a beam expander, an aperture, a beam scanner, a condenser lens, and the like.

[0116] The host controller 60 supplies the trigger signal Trg and the operation condition identification information ID to the power supply device 10, and supplies the trigger signal Trg to the high-frequency power supply 51. The host controller 60 also controls the beam scanner of the optical system 55 so that the incident position of the pulsed laser beam moves on the surface of the processing object 58. In addition, the host controller 60 controls the movable table 56 so that the processing object 58 moves in two directions parallel to its surface and orthogonal to each other.

[0117] The drilling process is performed by causing the pulsed laser beam to be incident on the object 58. In order to form a high-quality hole, the pulse width, peak intensity, etc. of the pulsed laser beam are controlled. For example, the pulse width is adjusted by changing the time Pex ( Figure 2 The peak intensity is adjusted by changing the duty cycle of the inverter of the high frequency power supply 51.

[0118] Fig.11 62. An input window is displayed on the output device 62, and the input window is used for the user to input the first voltage allowable range Var1 ( Figure 4 , Figure 6 ) and determine the second voltage tolerance range Var2( Figure 6 In addition, the input window also includes a radio button for the user to select the on-time setting value TonS ( Figure 7 ) or use the fixed on-time value TonF( Figure 3) is used as basic information for determining the on-time Ton1. As information for determining the first voltage allowable range Var1 and the second voltage allowable range Var2, for example, the upper limit value and the lower limit value of the voltage allowable range are used.

[0119] The user can operate the input device 61 such as a keyboard and a pointing device to input information for determining the first voltage allowable range Var1 and information for determining the second voltage allowable range Var2. In addition, as basic information for determining the on-time Ton1, the on-time setting value TonS ( Figure 7 ) or use the fixed on-time value TonF( Figure 3 ).

[0120] When the on-time setting value TonS is selected as the basic information for determining the on-time Ton1, the converter controller 30 operates the charging power source 20 in the on-time variable mode. When the on-time fixed value TonF is selected as the basic information for determining the on-time Ton1, the converter controller 30 operates the charging power source 20 in the on-time fixed mode.

[0121] The converter controller 30 has a function of associating the current on-time final value TonL with the operating condition and outputting it to the output device 62 .

[0122] Fig.12 1 is a diagram showing an example of an image in which the current on-time final value TonL is displayed on the output device 62. The value of the on-time final value TonL is associated with the operating condition identification information ID.

[0123] Next, Figure 10 to Figure 12 The excellent effects of the illustrated embodiment will be described.

[0124] By using the power supply device 10 of the laser device Figure 3 or Figure 7 The converter controller 30 shown can reduce the instability of the pulse energy at the start time of outputting the pulsed laser beam of the laser oscillator 52. Thus, laser processing can be performed from the start time of outputting the pulsed laser beam.

[0125] Since the user can set the first voltage tolerance range Var1 and the second voltage tolerance range Var2, the operating state or processing quality of the laser device can be evaluated to optimize the first voltage tolerance range Var1 and the second voltage tolerance range Var2. In addition, the user can confirm the value of the conduction time final value TonL output to the output device 62, thereby being able to infer the state of the laser device.

[0126] The above embodiments are examples. Of course, a part of the structure shown in different embodiments can be replaced or combined. The same effect based on the same structure of multiple embodiments is not described one by one in each embodiment. Moreover, the present invention is not limited to the above embodiments. For example, various changes, improvements, combinations, etc. can be made, which is obvious to those skilled in the art.

Claims

1. A power supply device comprising a charging power supply that performs a charging operation to bring a voltage between terminals of a capacitor connected to a load that performs an intermittent operation close to a voltage target value in synchronization with an operation of the load that performs an intermittent operation, The charging power source has a function of switching between a first operation mode and a second operation mode, wherein: In the first action mode, if the voltage between the terminals of the capacitor deviates from the first voltage allowable range, an auxiliary charge and discharge action is performed to make the voltage between the terminals of the capacitor close to the voltage target value. In the second action mode, if the voltage between the terminals of the capacitor deviates from the second voltage allowable range narrower than the first voltage allowable range, the auxiliary charge and discharge action is performed.

2. The power supply device according to claim 1, further comprising an input device for inputting information for determining the first voltage allowable range and the second voltage allowable range, The charging power source performs the auxiliary charge and discharge operation in one of the first operation mode and the second operation mode based on the information specifying the first voltage allowable range and the second voltage allowable range input from the input device.

3. The power supply device according to claim 1 or 2, wherein: The charging power supply includes a switching converter having a low-side switching element, and the charging operation is performed by switching the low-side switching element, thereby supplying a current corresponding to the on-time of the low-side switching element to the capacitor. The charging power supply has the following function: determining the on-time of the low-side switch element according to the deviation of the voltage between the terminals of the capacitor with respect to the voltage target value and the on-time setting value of the low-side switch element to perform the charging operation, The charging power source resets the on-time setting value according to an actual value of the on-time of the low-side switching element when the load is operating.

4. The power supply device according to claim 3, wherein: The load operates under a plurality of operating conditions with different power consumptions in one operating cycle. The charging power source stores the on-time setting value according to each operating condition of the load.

5. The power supply device according to claim 3, wherein: The charging power supply has a function of switching between a fixed on-time mode and a variable on-time mode, wherein, in the fixed on-time mode, the on-time of the low-side switch element is determined based on the deviation of the voltage between the terminals of the capacitor relative to the voltage target value and a predetermined fixed on-time value to perform the charging action, and in the variable on-time mode, the on-time of the low-side switch element is determined based on the on-time setting value of the low-side switch element to perform the charging action.

6. The power supply device according to claim 5, wherein: The charging power supply has a function of causing a user to input an instruction as to whether to operate in the variable on-time mode or the fixed on-time mode.

7. A power supply device, comprising: Capacitors, connected to loads that perform intermittent operation; and a charging power supply that performs a charging operation to bring the voltage between the terminals of the capacitor close to a voltage target value in synchronization with the operation of the load, The charging power supply includes a switching converter having a low-side switching element, and the charging operation is performed by switching the low-side switching element, thereby supplying a current corresponding to the on-time of the low-side switching element to the capacitor. The charging power supply has a function of determining an on-time of the low-side switching element according to a deviation of the voltage between the terminals of the capacitor from the voltage target value and an actual value of the on-time of the low-side switching element when the load is operating.

8. A laser device, comprising: A laser oscillator having a discharge electrode and performing pulse oscillation; a high frequency power source that converts direct current into alternating current in sync with a trigger signal and supplies the alternating current to the discharge electrode in a pulse form; and a power supply device for supplying direct current to the high frequency power supply, The power supply device comprises: a capacitor for storing direct current supplied to the high frequency power source; and a charging power supply that performs a charging operation in synchronization with the trigger signal so that the voltage between the terminals of the capacitor approaches a voltage target value, The charging power source has a function of switching between a first operation mode and a second operation mode, wherein: In the first action mode, if the voltage between the terminals of the capacitor deviates from the first voltage allowable range, an auxiliary charge and discharge action is performed to make the voltage between the terminals of the capacitor close to the voltage target value. In the second action mode, if the voltage between the terminals of the capacitor deviates from the second voltage allowable range narrower than the first voltage allowable range, the auxiliary charge and discharge action is performed.

9. A laser device, comprising: A laser oscillator having a discharge electrode and performing pulse oscillation; A high frequency power supply supplies alternating current in pulse form to the discharge electrode in synchronization with a trigger signal; and a power supply device for supplying direct current to the high frequency power supply, The power supply device comprises: a capacitor for storing direct current supplied to the high frequency power source; and a charging power supply that performs a charging operation in synchronization with the trigger signal so that the voltage between the terminals of the capacitor approaches a voltage target value, The charging power supply includes a switching converter having a low-side switching element, and the charging operation is performed by switching the low-side switching element, thereby supplying a current corresponding to the on-time of the low-side switching element to the capacitor. The charging power supply has a function of determining an on-time of the low-side switching element based on a deviation of the voltage between the terminals of the capacitor from the voltage target value and an actual value of the on-time of the low-side switching element during the charging operation.

Images