JP7377611B2

JP7377611B2 - power supply

Info

Publication number: JP7377611B2
Application number: JP2019044597A
Authority: JP
Inventors: 孝典青木; 隆史寺田; 智幸大塚; 陽輔粂
Original assignee: Nichicon Corp
Current assignee: Nichicon Corp
Priority date: 2019-03-12
Filing date: 2019-03-12
Publication date: 2023-11-10
Anticipated expiration: 2039-03-12
Also published as: JP2020150621A

Description

本発明は、プラズマ発生装置用の電源装置に関する。 The present invention relates to a power supply device for a plasma generator.

プラズマ発生装置用の電源装置は、プラズマ発生装置に大電流（プラズマ電流）を供給するためのものであり、このような電源装置としては、例えば、特許文献１に記載のものが知られている。 A power supply device for a plasma generation device is for supplying a large current (plasma current) to the plasma generation device, and as such a power supply device, for example, the one described in Patent Document 1 is known. .

プラズマ発生装置用の電源装置では、プラズマ電流を急峻に立ち上げるための回路（立上げ部）の制御と、立ち上げ後のプラズマ電流を平坦に維持するための回路（維持部）の制御が必要となる。特に、プラズマ発生装置に効率よくプラズマ電流を供給し、プラズマ発生装置に対する電気的および磁気的ストレスを低減するためには、立上げ部の制御と維持部の制御の切替えを円滑に行うことが求められる。 In a power supply device for a plasma generator, it is necessary to control the circuit (startup part) to sharply start up the plasma current, and the circuit (maintenance part) to keep the plasma current flat after startup. becomes. In particular, in order to efficiently supply plasma current to the plasma generator and reduce electrical and magnetic stress on the plasma generator, it is necessary to smoothly switch between control of the start-up section and control of the maintenance section. It will be done.

特開２０１５－１６７０７０号公報Japanese Patent Application Publication No. 2015-167070

本発明は上記事情に鑑みてなされたものであって、その課題とするところは、プラズマ電流を立ち上げるための制御とプラズマ電流を平坦に維持するための制御との切替えを円滑に行うことが可能な電源装置を提供することにある。 The present invention has been made in view of the above circumstances, and its object is to smoothly switch between control for raising the plasma current and control for maintaining the plasma current flat. The purpose is to provide a possible power supply device.

上記課題を解決するために、本発明に係る電源装置は、
プラズマ発生装置にプラズマを発生させるためのプラズマ電流を供給する電源装置であって、
コンデンサと、前記コンデンサを放電させるための放電用スイッチとを含み、前記コンデンサの放電電流を前記プラズマ発生装置に供給することで、前記プラズマ電流を所定の第１電流値まで立ち上げる立上げ部と、
前記立上げ部の入力側に接続されたインバータ回路を含み、前記インバータ回路の出力電流を前記立上げ部を介して前記プラズマ発生装置に供給することで、前記プラズマ電流を前記第１電流値よりも大の第２電流値に維持する維持部と、
前記インバータ回路を制御する制御部と、
を備え、
前記制御部は、
前記プラズマ電流が前記第１電流値よりも小の場合は、前記維持部の出力電圧を前記立上げ部の出力電圧に一致させる定電圧制御を行い、
前記プラズマ電流が前記第１電流値よりも大で前記第２電流値よりも小の場合は、前記プラズマ電流の電流値を所定の目標電流値に一致させるとともに、前記目標電流値を前記第２電流値に向けて所定の勾配で増加させる第１定電流制御を行い、
前記プラズマ電流が前記第２電流値に達した場合は、前記目標電流値を前記第２電流値とする第２定電流制御を行うことを特徴とする。 In order to solve the above problems, a power supply device according to the present invention includes:
A power supply device that supplies a plasma current for generating plasma to a plasma generator,
a start-up unit that includes a capacitor and a discharge switch for discharging the capacitor, and starts up the plasma current to a predetermined first current value by supplying the discharge current of the capacitor to the plasma generator; ,
an inverter circuit connected to the input side of the startup section, and by supplying an output current of the inverter circuit to the plasma generation device via the startup section, the plasma current is lower than the first current value. a maintaining unit that maintains the second current value at a higher value;
a control unit that controls the inverter circuit;
Equipped with
The control unit includes:
When the plasma current is smaller than the first current value, constant voltage control is performed to match the output voltage of the sustaining section to the output voltage of the rising section;
When the plasma current is larger than the first current value and smaller than the second current value, the current value of the plasma current is made to match a predetermined target current value, and the target current value is set to the second current value. Performing first constant current control to increase the current value at a predetermined slope,
When the plasma current reaches the second current value, second constant current control is performed to set the target current value to the second current value.

この構成によれば、制御部がプラズマ電流の目標電流値を第１電流値から第２電流値に向けて所定の勾配で増加させる第１定電流制御を行うので、プラズマ電流を立ち上げるための制御（定電圧制御）とプラズマ電流を平坦に維持するための制御（第２定電流制御）との切替えを円滑に行うことができる。 According to this configuration, the control unit performs the first constant current control to increase the target current value of the plasma current from the first current value to the second current value at a predetermined gradient, so that It is possible to smoothly switch between control (constant voltage control) and control for maintaining a flat plasma current (second constant current control).

上記電源装置は、
前記立上げ部と前記維持部との間に介装され、オフ状態のときに前記立上げ部と前記維持部とを電気的に切り離し、オン状態のときに前記立上げ部と前記維持部とを電気的に接続する接続スイッチをさらに備え、
前記接続スイッチは、前記定電圧制御時にオフ状態となる一方、前記第１定電流制御時および前記第２定電流制御時にオン状態となることが好ましい。 The above power supply device is
interposed between the rising part and the maintaining part, electrically disconnecting the rising part and the maintaining part when in the off state, and disconnecting the rising part and the maintaining part when in the on state; further comprising a connection switch for electrically connecting the
Preferably, the connection switch is in an off state during the constant voltage control, and is in an on state during the first constant current control and the second constant current control.

この構成によれば、定電圧制御時に、立上げ部から維持部に電流が逆流してしまうのを防ぐことができるので、プラズマ発生装置に効率よくプラズマ電流を供給することができる。 According to this configuration, it is possible to prevent current from flowing backward from the startup section to the maintenance section during constant voltage control, so that plasma current can be efficiently supplied to the plasma generator.

上記電源装置において、
前記制御部は、
前記インバータ回路をＰＷＭ制御するＰＷＭ制御部と、
前記維持部の出力電圧と前記立上げ部の出力電圧との差分を演算し、前記差分に応じた第１信号を出力する第１演算部と、
前記プラズマ電流の電流値と前記目標電流値との差分を演算し、前記差分に応じた第２信号を出力する第２演算部と、
前記第１信号または前記第２信号のいずれか一方を選択して前記ＰＷＭ制御部に出力する制御切替スイッチと、
を備えるよう構成できる。 In the above power supply device,
The control unit includes:
a PWM control unit that performs PWM control on the inverter circuit;
a first calculation unit that calculates a difference between the output voltage of the sustaining unit and the output voltage of the rising unit and outputs a first signal according to the difference;
a second calculation unit that calculates a difference between the current value of the plasma current and the target current value and outputs a second signal according to the difference;
a control changeover switch that selects either the first signal or the second signal and outputs the selected signal to the PWM control unit;
It can be configured to have

上記電源装置において、
前記制御部は、
前記目標電流値を前記第２電流値に向けて所定の勾配で増加させるための第３信号を出力するスロープ生成部と、
前記目標電流値を前記第２電流値にするための第４信号を出力する目標電流設定部と、
前記第３信号または前記第４信号のいずれか一方を選択し、前記目標電流値として前記第２演算部に出力する目標電流切替スイッチと、
をさらに備えるよう構成できる。 In the above power supply device,
The control unit includes:
a slope generation unit that outputs a third signal for increasing the target current value toward the second current value at a predetermined slope;
a target current setting unit that outputs a fourth signal for setting the target current value to the second current value;
a target current changeover switch that selects either the third signal or the fourth signal and outputs it to the second calculation unit as the target current value;
It can be configured to further include:

本発明によれば、プラズマ電流を立ち上げるための制御とプラズマ電流を平坦に維持するための制御との切替えを円滑に行うことが可能な電源装置を提供することができる。 According to the present invention, it is possible to provide a power supply device that can smoothly switch between control for raising a plasma current and control for maintaining a flat plasma current.

本発明に係る電源装置を示す図である。1 is a diagram showing a power supply device according to the present invention. 本発明に係る電源装置に含まれる各スイッチのタイミングチャートである。5 is a timing chart of each switch included in the power supply device according to the present invention. 本発明に係る電源装置の制御の切替えを説明するための図である。FIG. 3 is a diagram for explaining switching of control of the power supply device according to the present invention.

以下、添付図面を参照して、本発明に係る電源装置の実施形態について説明する。 DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a power supply device according to the present invention will be described with reference to the accompanying drawings.

図１に、本発明の一実施形態に係る電源装置１００を示す。電源装置１００は、誘導性負荷２０１（コイルＬ１、Ｌ２）を介して、プラズマ発生装置２０２にプラズマを発生させるための大電流（プラズマ電流）を供給する。電源装置１００は、立上げ部１０と、維持部２０と、立上げ部１０と維持部２０との間に介装された接続スイッチＳＷ１と、制御部３０とを備える。誘導性負荷２０１およびプラズマ発生装置２０２は、電源装置１００の構成ではない。 FIG. 1 shows a power supply device 100 according to an embodiment of the present invention. Power supply device 100 supplies a large current (plasma current) for generating plasma to plasma generation device 202 via inductive load 201 (coils L1, L2). The power supply device 100 includes a startup section 10, a maintenance section 20, a connection switch SW1 interposed between the startup section 10 and the maintenance section 20, and a control section 30. Inductive load 201 and plasma generator 202 are not components of power supply device 100 .

立上げ部１０は、プラズマ電流を所定の第１電流値Ｉ_１まで急峻に立ち上げるための回路である。立上げ部１０の入力側には、接続スイッチＳＷ１を介して維持部２０が接続され、立上げ部１０の出力側には、誘導性負荷２０１を介してプラズマ発生装置２０２が接続される。立上げ部１０は、放電回路１１と、還流回路１２と、第１電圧検出手段１３とを備える。 The startup unit 10 is a circuit for rapidly raising the plasma current to a predetermined first current value _I1 . A maintenance section 20 is connected to the input side of the startup section 10 via a connection switch SW1, and a plasma generation device 202 is connected to the output side of the startup section 10 via an inductive load 201. The startup section 10 includes a discharge circuit 11 , a reflux circuit 12 , and a first voltage detection means 13 .

放電回路１１は、スイッチＱ１、ダイオードＤ１およびコンデンサＣ１を直列接続した第１直列回路と、スイッチＱ２、ダイオードＤ２およびコンデンサＣ２を直列接続した第２直列回路とを備える。スイッチＱ１、Ｑ２は、本発明の「放電用スイッチ」に相当し、例えば、ＩＧＢＴ等のパワー半導体スイッチを用いる。コンデンサＣ１は、例えば、コンデンサＣ２よりも静電容量が小さく、定格電圧が大きいコンデンサを用いる。 The discharge circuit 11 includes a first series circuit in which a switch Q1, a diode D1, and a capacitor C1 are connected in series, and a second series circuit in which a switch Q2, a diode D2, and a capacitor C2 are connected in series. The switches Q1 and Q2 correspond to the "discharge switch" of the present invention, and use power semiconductor switches such as IGBTs, for example. As the capacitor C1, for example, a capacitor having a smaller capacitance and a higher rated voltage than the capacitor C2 is used.

還流回路１２は、誘導性負荷２０１を構成する１次側のコイルＬ１のエネルギーを吸収するための回路で、スイッチＱ３、ダイオードＤ３および抵抗Ｒ１を直列接続した第３直列回路を備える。スイッチＱ３は、例えば、ＩＧＢＴ等のパワー半導体スイッチを用いる。 The free wheel circuit 12 is a circuit for absorbing the energy of the primary side coil L1 that constitutes the inductive load 201, and includes a third series circuit in which a switch Q3, a diode D3, and a resistor R1 are connected in series. For example, a power semiconductor switch such as an IGBT is used as the switch Q3.

第１電圧検出手段１３は、立上げ部１０のコンデンサＣ１の端子間に接続され、コンデンサＣ１の端子間電圧を立上げ部１０の出力電圧Ｖ_２として検出する。第１電圧検出手段１３の検出結果は、所定の周期で制御部３０に出力される。ここで、第１電圧検出手段１３は、コンデンサＣ１の端子間電圧に替えて、立上げ部１０の出力端Ｔ１、Ｔ２間の電圧を立上げ部１０の出力電圧Ｖ_２として検出してもよいが、コンデンサＣ１の端子間電圧を検出することで、維持部２０の出力電圧（後述する維持部２０のコンデンサＣ３に対する初期充電後の電圧）との電圧差を低減し、接続スイッチＳＷ１および放電用のスイッチＱ１、Ｑ２に印加されるサージ電圧の発生を抑えることができる。 The first voltage detection means 13 is connected between the terminals of the capacitor C1 of the rising section 10, and detects the voltage between the terminals of the capacitor C1 as the output voltage _V2 of the rising section 10. The detection result of the first voltage detection means 13 is outputted to the control section 30 at a predetermined period. Here, the first voltage detection means 13 may detect the voltage between the output terminals T1 and T2 of the rising section 10 as the output voltage _V2 of the rising section 10 instead of the voltage between the terminals of the capacitor C1. However, by detecting the voltage between the terminals of the capacitor C1, the voltage difference with the output voltage of the sustaining unit 20 (the voltage after initial charging of the capacitor C3 of the sustaining unit 20, which will be described later) is reduced, and the connection switch SW1 and the discharging The generation of surge voltage applied to the switches Q1 and Q2 can be suppressed.

維持部２０は、立ち上げ後のプラズマ電流を平坦に（第１電流値Ｉ_１よりも大の第２電流値Ｉ_２に）維持するための回路である。維持部２０の入力側には、図示していない直流電源が接続され、維持部２０の出力側には、接続スイッチＳＷ１を介して立上げ部１０が接続される。維持部２０は、コンデンサ２１と、インバータ回路２２と、第２電圧検出手段２３とを備える。 The maintenance unit 20 is a circuit for maintaining a flat plasma current after startup (to a second current value _I2 that is larger than the first current value I1) _. A DC power supply (not shown) is connected to the input side of the maintenance section 20, and the startup section 10 is connected to the output side of the maintenance section 20 via a connection switch SW1. The maintenance section 20 includes a capacitor 21, an inverter circuit 22, and a second voltage detection means 23.

コンデンサ２１は、インバータ回路２２の入力側において、上記の図示していない直流電源の入力端間に接続される。コンデンサ２１の電圧は、インバータ回路２２の出力電圧よりも大となる。 The capacitor 21 is connected between the input terminals of the DC power supply (not shown) on the input side of the inverter circuit 22 . The voltage of the capacitor 21 is higher than the output voltage of the inverter circuit 22.

インバータ回路２２は、ブリッジ接続されたスイッチＱ４～Ｑ７と、コイルＬ３、Ｌ４と、コンデンサＣ３とを備える。コンデンサＣ３は、一端がコイルＬ３を介してスイッチＱ４、Ｑ５の接続点に接続され、他端がコイルＬ４を介してスイッチＱ６、Ｑ７の接続点に接続される。スイッチＱ４～Ｑ７は、例えば、ＩＧＢＴ等のパワー半導体スイッチを用いる。 The inverter circuit 22 includes bridge-connected switches Q4 to Q7, coils L3 and L4, and a capacitor C3. The capacitor C3 has one end connected to the connection point between the switches Q4 and Q5 via the coil L3, and the other end connected to the connection point between the switches Q6 and Q7 via the coil L4. For the switches Q4 to Q7, power semiconductor switches such as IGBTs are used, for example.

第２電圧検出手段２３は、インバータ回路２２の出力端間に接続され、インバータ回路２２の出力電圧、すなわち維持部２０の出力電圧Ｖ_１を検出する。第２電圧検出手段２３の検出結果は、所定の周期で制御部３０に出力される。 The second voltage detection means 23 is connected between the output terminals of the inverter circuit 22 and detects the output voltage of the inverter circuit 22, that is, the output voltage _V1 of the sustaining section 20. The detection result of the second voltage detection means 23 is outputted to the control section 30 at a predetermined period.

接続スイッチＳＷ１は、オフ状態のときに立上げ部１０と維持部２０とを電気的に切り離し、オン状態のときに立上げ部１０と維持部２０とを電気的に接続する。接続スイッチＳＷ１は、例えば、互いに逆方向に直列接続されたＩＧＢＴ等のパワー半導体スイッチを用いる。 The connection switch SW1 electrically disconnects the rising part 10 and the maintaining part 20 when in the off state, and electrically connects the rising part 10 and the maintaining part 20 when in the on state. The connection switch SW1 uses, for example, power semiconductor switches such as IGBTs connected in series in opposite directions.

制御部３０は、立上げ部１０および維持部２０を制御するための回路で、例えば、デジタル回路および／またはアナログ回路で構成される。制御部３０は、放電制御部３１と、ＰＷＭ制御部３２と、接続制御部３３と、第１演算部３４と、電流検出手段３５と、第２演算部３６と、スロープ生成部３７と、目標電流設定部３８と、制御切替スイッチＳＷ２と、目標電流切替スイッチＳＷ３とを備える。 The control unit 30 is a circuit for controlling the startup unit 10 and the maintenance unit 20, and is configured of, for example, a digital circuit and/or an analog circuit. The control unit 30 includes a discharge control unit 31, a PWM control unit 32, a connection control unit 33, a first calculation unit 34, a current detection unit 35, a second calculation unit 36, a slope generation unit 37, and a target It includes a current setting section 38, a control changeover switch SW2, and a target current changeover switch SW3.

放電制御部３１は、立上げ部１０のスイッチＱ１～Ｑ３の制御を行う。ＰＷＭ制御部３２は、維持部２０のインバータ回路２２に含まれるスイッチＱ４～Ｑ７の制御（本実施形態では、ＰＷＭ制御）を行う。また、接続制御部３３は、接続スイッチＳＷ１の制御を行う。 The discharge control section 31 controls the switches Q1 to Q3 of the startup section 10. The PWM control section 32 controls the switches Q4 to Q7 included in the inverter circuit 22 of the maintenance section 20 (in this embodiment, PWM control). Further, the connection control unit 33 controls the connection switch SW1.

また、電源装置１００は、立上げ部１０の放電用のスイッチＱ１、Ｑ２をオン（放電動作）させる前に、維持部２０の出力電圧Ｖ_１が立上げ部１０の出力電圧Ｖ_２に一致するようにコンデンサＣ３を充電する初期充電機能を備える。これにより、放電用のスイッチＱ１、Ｑ２がオンする際の維持部２０へのサージ電流の流入を抑制することができる。 Further, in the power supply device 100, before turning on (discharging operation) the discharge switches Q1 and Q2 of the startup section 10, the output voltage _V1 of the maintenance section 20 matches the output voltage _V2 of the startup section 10. It has an initial charging function to charge the capacitor C3 as shown in FIG. Thereby, it is possible to suppress the surge current from flowing into the maintenance section 20 when the discharge switches Q1 and Q2 are turned on.

図２に示すように、放電制御部３１は、時刻ｔ_１において、スイッチＱ１、Ｑ２をターンオンさせて、放電回路１１のコンデンサＣ１、Ｃ２を放電させる。時刻ｔ_２になると、放電制御部３１は、スイッチＱ１、Ｑ２をターンオフさせるとともにスイッチＱ３をターンオンさせて、還流回路１２の抵抗Ｒ１にコイルＬ１のエネルギーを吸収させる。その後の時刻ｔ_３において、放電制御部３１はスイッチＱ３をターンオフさせる。 As shown in FIG. 2, the discharge control unit 31 turns on the switches Q1 and Q2 at time _t1 to discharge the capacitors C1 and C2 of the discharge circuit 11. At time _t2 , the discharge control section 31 turns off the switches Q1 and Q2 and turns on the switch Q3, thereby causing the resistor R1 of the freewheeling circuit 12 to absorb the energy of the coil L1. At subsequent time _t3 , the discharge control section 31 turns off the switch Q3.

ＰＷＭ制御部３２は、放電制御部３１がスイッチＱ１～Ｑ３の制御を行っている間、スイッチＱ４～Ｑ７のＰＷＭ制御を継続し、プラズマ電流の供給が終了する時刻ｔ_５において、スイッチＱ４～Ｑ７のＰＷＭ制御を終了させる。 The PWM control section 32 continues the PWM control of the switches Q4 to Q7 while the discharge control section 31 is controlling the switches Q1 to Q3, and at time _t5 when the supply of plasma current ends, the PWM control section 32 controls the switches Q4 to Q7. PWM control is terminated.

接続制御部３３は、プラズマ電流の電流値Ｉ_ｐが第１電流値Ｉ_１に達したタイミングで（図２では、時刻ｔ_３において）、接続スイッチＳＷ１をターンオンさせる一方、スイッチＱ４～Ｑ７のＰＷＭ制御を終了させるタイミングで（図２では、時刻ｔ_５において）、接続スイッチＳＷ１をターンオフさせる。 The connection control unit 33 turns on the connection switch SW1 at the timing when the current value _Ip of the plasma current reaches the first current value _I1 (at time _t3 in FIG. 2), and turns on the PWM of the switches Q4 to Q7. At the timing to end the control (at time _t5 in FIG. 2), the connection switch SW1 is turned off.

第１演算部３４は、第２電圧検出手段２３で検出した維持部２０の出力電圧Ｖ_１と第１電圧検出手段１３で検出した立上げ部１０の出力電圧Ｖ_２（＝目標電圧値Ｖ_ｒｅｆ）との差分を演算し、当該差分に応じた第１信号ｖを制御切替スイッチＳＷ２に出力する。 The first calculation unit 34 calculates the output voltage V ₁ of the maintenance unit 20 detected by the second voltage detection unit 23 and the output voltage V 2 of the startup unit 10 detected by the first voltage detection unit ₁₃ (=target voltage value V _ref ) and outputs a first signal v corresponding to the difference to the control changeover switch SW2.

電流検出手段３５は、誘導性負荷２０１の二次側のコイルＬ２に流れるプラズマ電流の電流値Ｉ_ｐを検出する。電流検出手段３５の検出結果（電流値Ｉ_ｐ）は、所定の周期で第２演算部３６等に出力される。 The current detection means 35 detects the current value _Ip of the plasma current flowing through the secondary coil L2 of the inductive load 201. The detection result (current value I _p ) of the current detection means 35 is outputted to the second calculation unit 36 etc. at a predetermined period.

第２演算部３６は、電流検出手段３５で検出したプラズマ電流の電流値Ｉ_ｐとプラズマ電流の目標電流値Ｉ_ｒｅｆとの差分を演算し、当該差分に応じた第２信号ｃを制御切替スイッチＳＷ２に出力する。 The second calculation unit 36 calculates the difference between the current value I _p of the plasma current detected by the current detection means 35 and the target current value I _ref of the plasma current, and sends a second signal c corresponding to the difference to the control changeover switch. Output to SW2.

スロープ生成部３７は、電流検出手段３５で検出したプラズマ電流の電流値Ｉ_ｐと目標電流設定部３８で設定された設定電流値Ｉ_ｓｅｔとに基づいて、電流値Ｉ_ｐが第１電流値Ｉ_１に達するまでは目標電流値Ｉ_ｒｅｆを第１電流値Ｉ_１とし、電流値Ｉ_ｐが第１電流値Ｉ_１に達した後は目標電流値Ｉ_ｒｅｆを所定の勾配で設定電流値Ｉ_ｓｅｔ（＝第２電流値Ｉ_２）まで増加させるための第３信号ａを、目標電流切替スイッチＳＷ３に出力する。スロープ生成部３７は、例えば、ロジックＩＣを用いる。 The slope generating section 37 determines that the current value I p is the first current value I based on the current value I _p of the plasma current detected by the current detecting means 35 and _{the set} current value _I set set by the target current setting section 38 . The target current value I _ref is set to the first current value I ₁ until the current value I ref reaches ₁ , and after the current value I _p reaches the first current value I ₁ , the target current value I _ref is set to the set current value I _set at a predetermined slope. A third signal a for increasing the current to (=second current value I ₂ ) is output to the target current changeover switch SW3. The slope generation unit 37 uses, for example, a logic IC.

目標電流設定部３８は、目標電流値Ｉ_ｒｅｆを設定電流値Ｉ_ｓｅｔとするための第４信号ｂを目標電流切替スイッチＳＷ３に出力する。本実施形態では、設定電流値Ｉ_ｓｅｔは、第２電流値Ｉ_２に設定されている。 The target current setting unit 38 outputs a fourth signal b for setting the target current value I _ref to _{the set} current value I set to the target current changeover switch SW3. In this embodiment, the set current value I _set is set to the second current value I ₂ .

制御切替スイッチＳＷ２は、電流検出手段３５で検出したプラズマ電流の電流値Ｉ_ｐに応じて、第１演算部３４から出力された第１信号ｖまたは第２演算部３６から出力された第２信号ｃのいずれか一方を選択し、ＰＷＭ制御部３２に出力する。制御切替スイッチＳＷ２は、電流値Ｉ_ｐが第１電流値Ｉ_１に達するまでは第１信号ｖを選択する一方、電流値Ｉ_ｐが第１電流値Ｉ_１に達した後は第２信号ｃを選択する。制御切替スイッチＳＷ２は、例えば、マルチプレクサを用いる。 The control changeover switch SW2 selects the first signal v outputted from the first calculation section 34 or the second signal outputted from the second calculation section 36, depending on the current value _Ip of the plasma current detected by the current detection means 35. c is selected and output to the PWM control section 32. The control changeover switch SW2 selects the first signal v until the current value _Ip reaches the first current value _I1 , and selects the second signal c after the current value _Ip reaches the first current value _I1 . Select. For example, a multiplexer is used as the control changeover switch SW2.

目標電流切替スイッチＳＷ３は、電流検出手段３５で検出した電流値Ｉ_ｐに応じて、スロープ生成部３７から出力された第３信号ａまたは目標電流設定部３８から出力された第４信号ｂのいずれか一方を選択し、目標電流値Ｉ_ｒｅｆとして第２演算部３６に出力する。目標電流切替スイッチＳＷ３は、電流値Ｉ_ｐが第２電流値Ｉ_２に達するまでは第３信号ａを選択する一方、電流値Ｉ_ｐが第２電流値Ｉ_２に達した後は第４信号ｂを選択する。目標電流切替スイッチＳＷ３は、例えば、マルチプレクサを用いる。 The target current changeover switch SW3 selects either the third signal a outputted from the slope generation section 37 or the fourth signal b outputted from the target current setting section 38, depending on the current value _Ip detected by the current detection means 35. One of them is selected and outputted to the second calculation unit 36 as the target current value I _ref . The target current changeover switch SW3 selects the third signal a until the current value _Ip reaches the second current value _I2 , and selects the fourth signal a after the current value _Ip reaches the second current value _I2 . Select b. For example, a multiplexer is used as the target current changeover switch SW3.

図３に示すように、電流値Ｉ_ｐが第１電流値Ｉ_１に達するまで（時刻ｔ_３以前）は、接続スイッチＳＷ１がオフ状態になり、立上げ部１０と維持部２０は電気的に切り離された状態になる。 As shown in FIG. 3, until the current value _Ip reaches the first current value _I1 (before time _t3 ), the connection switch SW1 is in the off state, and the start-up section 10 and the maintenance section 20 are electrically connected. become disconnected.

また、時刻ｔ_３以前は、制御切替スイッチＳＷ２が第１信号ｖを選択するので、ＰＷＭ制御部３２は、維持部２０の出力電圧Ｖ_１を立上げ部１０の出力電圧Ｖ_２に一致させるようにインバータ回路２２を制御する（定電圧制御）。この間に、プラズマ電流は第１電流値Ｉ_１まで急峻に立ち上がる。 Furthermore, before time _t3 , the control changeover switch SW2 selects the first signal v, so the PWM control unit 32 makes the output voltage _V1 of the sustaining unit 20 match the output voltage _V2 of the rising unit 10. The inverter circuit 22 is controlled (constant voltage control). During this time, the plasma current rises steeply to the first current value _I1 .

次いで、電流値Ｉ_ｐが第２電流値Ｉ_２に達するまで（時刻ｔ_３～時刻ｔ_４）は、接続スイッチＳＷ１がオン状態になり、立上げ部１０と維持部２０は電気的に接続された状態になる。 Next, until the current value I _p reaches the second current value I ₂ (from time t ₃ to time t ₄ ), the connection switch SW1 is in the on state, and the startup section 10 and the maintenance section 20 are electrically connected. state.

また、時刻ｔ_３～時刻ｔ_４では、制御切替スイッチＳＷ２が第２信号ｃを選択し、目標電流切替スイッチＳＷ３が第３信号ａを選択する。ＰＷＭ制御部３２は、電流値Ｉ_ｐが第１電流値Ｉ_１から第２電流値Ｉ_２に向けて所定の勾配（スロープ生成部３７で設定された勾配）で増加するように、インバータ回路２２を制御する（第１定電流制御）。すなわち、この間に、プラズマ電流を第１電流値Ｉ_１から第２電流値Ｉ_２まで緩やかにつなぎ、制御の切替えに伴う不連続性を抑制する。なお、この間は、数ｍｓ程度である。 Further, from time t ₃ to time t ₄ , the control changeover switch SW2 selects the second signal c, and the target current changeover switch SW3 selects the third signal a. The PWM control unit 32 controls the inverter circuit 22 so that the current value _Ip increases from the first current value _I1 to the second current value _I2 at a predetermined slope (the slope set by the slope generation unit 37). (first constant current control). That is, during this time, the plasma current is gradually connected from the first current value I ₁ to the second current value I ₂ to suppress discontinuity due to control switching. Note that this period is approximately several ms.

次いで、電流値Ｉ_ｐが第２電流値Ｉ_２に達した後（時刻ｔ_４～時刻ｔ_５）は、接続スイッチＳＷ１がオン状態、制御切替スイッチＳＷ２が第２信号ｃを選択したまま、目標電流切替スイッチＳＷ３が第４信号ｂを選択する。ＰＷＭ制御部３２は、電流値Ｉ_ｐを第２電流値Ｉ_２に一致させるように、インバータ回路２２を制御する（第２定電流制御）。この間は、プラズマ電流が平坦に維持される。 Next, after the current value I _p reaches the second current value I ₂ (from time t ₄ to time t ₅ ), the target is set while the connection switch SW1 remains on and the control changeover switch SW2 selects the second signal c. The current changeover switch SW3 selects the fourth signal b. The PWM control unit 32 controls the inverter circuit 22 so that the current value I _p matches the second current value I ₂ (second constant current control). During this time, the plasma current is maintained flat.

本実施形態に係る電源装置１００によれば、上記のとおり、制御部３０がプラズマ電流を第１電流値Ｉ_１から第２電流値Ｉ_２に向けて所定の勾配で増加させる第１定電流制御を行うので、プラズマ電流を立ち上げるための制御（定電圧制御）とプラズマ電流を平坦に維持するための制御（第２定電流制御）との切替えを円滑に行うことができる。 According to the power supply device 100 according to the present embodiment, as described above, the control unit 30 performs the first constant current control in which the plasma current is increased at a predetermined gradient from the first current value _I1 to the second current value _I2 . Therefore, it is possible to smoothly switch between the control for raising the plasma current (constant voltage control) and the control for maintaining the plasma current flat (second constant current control).

また、本実施形態に係る電源装置１００によれば、定電圧制御時に接続スイッチＳＷ１がオフ状態になるので、立上げ部１０のコンデンサＣ１、Ｃ２から維持部２０のコンデンサＣ３に電流が逆流するのを防ぐことができる。その結果、プラズマ発生装置２０２に効率よくプラズマ電流を供給することができる。 Further, according to the power supply device 100 according to the present embodiment, since the connection switch SW1 is turned off during constant voltage control, current does not flow backward from the capacitors C1 and C2 of the startup section 10 to the capacitor C3 of the maintenance section 20. can be prevented. As a result, plasma current can be efficiently supplied to the plasma generator 202.

以上、本発明に係る電源装置の実施形態について説明したが、本発明は上記実施形態に限定されるものではない。 Although the embodiments of the power supply device according to the present invention have been described above, the present invention is not limited to the above embodiments.

本発明の立上げ部は、コンデンサと、コンデンサを放電させるための放電用スイッチとを含み、コンデンサの放電電流をプラズマ発生装置に供給することで、プラズマ電流を所定の第１電流値まで立ち上げるのであれば、適宜構成を変更できる。 The startup section of the present invention includes a capacitor and a discharge switch for discharging the capacitor, and supplies the discharge current of the capacitor to the plasma generator to ramp up the plasma current to a predetermined first current value. If so, you can change the configuration as appropriate.

また、上記実施形態において、立ち上げ部１０のスイッチＱ１～Ｑ３をオン／オフさせるタイミングは適宜変更できる。例えば、スイッチＱ３を時刻ｔ_１以前から時刻ｔ_５以降までオンさせたままでもよいし、コンデンサＣ１、Ｃ２を順に放電させるようにスイッチＱ１、Ｑ２をオン／オフさせてもよい。 Furthermore, in the above embodiment, the timing at which the switches Q1 to Q3 of the startup section 10 are turned on and off can be changed as appropriate. For example, the switch Q3 may be left on from before time _t1 until after time _t5 , or the switches Q1 and Q2 may be turned on and off so as to sequentially discharge the capacitors C1 and C2.

また、上記実施形態では、第１電圧検出手段１３は、立上げ部１０の出力電圧Ｖ_２としてコンデンサＣ１の両端子間電圧を検出しているが、これに限定されず、上述のとおり、立上げ部１０の出力端Ｔ１、Ｔ２間の電圧を検出してもよい。また、第１電圧検出手段１３は、立上げ部１０の出力電圧Ｖ_２としてコンデンサＣ２の両端子間電圧を検出してもよい。特にコンデンサＣ２の端子間電圧がコンデンサＣ１の端子間電圧よりも高くなるような設計条件下では、維持部２０の出力電圧との電圧差に起因するサージ電圧の発生を抑制する上で有効である。 Further, in the above embodiment, the first voltage detection means 13 detects the voltage between both terminals of the capacitor C1 as the output voltage _V2 of the startup section 10, but the invention is not limited to this. The voltage between the output ends T1 and T2 of the raising section 10 may be detected. Further, the first voltage detection means 13 may detect the voltage between both terminals of the capacitor C2 as the output voltage _V2 of the rising section 10. Particularly under design conditions in which the voltage between the terminals of the capacitor C2 is higher than the voltage between the terminals of the capacitor C1, this is effective in suppressing the generation of surge voltage due to the voltage difference with the output voltage of the sustaining section 20. .

本発明の維持部は、立上げ部の入力側に接続されたインバータ回路を含み、インバータ回路の出力電流を立上げ部を介してプラズマ発生装置に供給することで、プラズマ電流を第１電流値よりも大の第２電流値に維持するのであれば、適宜構成を変更できる。 The maintenance section of the present invention includes an inverter circuit connected to the input side of the startup section, and supplies the output current of the inverter circuit to the plasma generator through the startup section, thereby adjusting the plasma current to a first current value. As long as the second current value is maintained at a value larger than , the configuration can be changed as appropriate.

本発明の制御部は、（１）プラズマ電流が第１電流値よりも小の場合は、維持部の出力電圧を立上げ部の出力電圧に一致させる定電圧制御を行い、（２）プラズマ電流が第１電流値よりも大で第２電流値よりも小の場合は、プラズマ電流の電流値を所定の目標電流値に一致させるとともに、目標電流値を第２電流値に向けて所定の勾配で増加させる第１定電流制御を行い、（３）プラズマ電流が第２電流値に達した場合は、目標電流値を第２電流値とする第２定電流制御を行うのであれば、適宜構成を変更できる。 The control unit of the present invention (1) performs constant voltage control to match the output voltage of the sustaining unit with the output voltage of the startup unit when the plasma current is smaller than the first current value; is larger than the first current value and smaller than the second current value, the current value of the plasma current is made to match the predetermined target current value, and the target current value is adjusted to a predetermined slope toward the second current value. (3) When the plasma current reaches the second current value, if the second constant current control is performed in which the target current value is set to the second current value, the configuration can be performed as appropriate. can be changed.

第１定電流制御時におけるプラズマ電流の増加の勾配は、定電圧制御時（電流立ち上げ時）におけるプラズマ電流の増加の勾配よりも緩やかであればよい。 The gradient of increase in plasma current during the first constant current control may be gentler than the gradient of increase in plasma current during constant voltage control (at the time of current rise).

定電圧制御時に立上げ部から維持部に電流が逆流するのを許容できるのであれば、立上げ部と維持部との間に介装される接続スイッチを省略してもよい。 If it is possible to allow current to flow back from the start-up section to the maintenance section during constant voltage control, the connection switch interposed between the start-up section and the maintenance section may be omitted.

１００電源装置
２０１誘導性負荷
２０２プラズマ発生装置
１０立上げ部
１１放電回路
１２還流回路
１３第１電圧検出手段
２０維持部
２１コンデンサ
２２インバータ回路
２３第２電圧検出手段
３０制御部
３１放電制御部
３２ＰＷＭ制御部
３３接続制御部
３４第１演算部
３５電流検出手段
３６第２演算部
３７スロープ生成部
３８目標電流設定部
ＳＷ１接続スイッチ
ＳＷ２制御切替スイッチ
ＳＷ３目標電流切替スイッチ 100 Power supply device 201 Inductive load 202 Plasma generation device 10 Startup section 11 Discharge circuit 12 Freewheel circuit 13 First voltage detection means 20 Maintenance section 21 Capacitor 22 Inverter circuit 23 Second voltage detection means 30 Control section 31 Discharge control section 32 PWM Control section 33 Connection control section 34 First calculation section 35 Current detection means 36 Second calculation section 37 Slope generation section 38 Target current setting section SW1 Connection switch SW2 Control changeover switch SW3 Target current changeover switch

Claims

A power supply device that supplies a direct current plasma current for generating plasma to a plasma generator,
It includes a discharge capacitor and a discharge switch for discharging the discharge capacitor, and supplies the discharge current of the discharge capacitor to the plasma generator to increase the plasma current to a predetermined first current value. A start-up section that starts up the
A maintenance unit including a bridge circuit in which a plurality of switches are bridge-connected, an input capacitor connected to an input side of the bridge circuit, and an output capacitor connected to an output side of the bridge circuit, the maintenance unit comprising: After increasing the plasma current from the first current value to a second current value larger than the first current value by supplying a direct current output current to the plasma generation device via the startup section. , the maintaining unit that maintains the current at the second current value;
a control unit that controls the discharge switch and the plurality of switches;
Equipped with
The control unit includes:
During the first period until the plasma current reaches the first current value , the plurality of PWM control is performed on the switch based on the difference between the voltage across the output capacitor and the voltage across the discharge capacitor , and constant voltage control is performed to match the voltage across the output capacitor with the voltage across the discharge capacitor. conduct ,
During a second period from when the plasma current reaches the first current value until it reaches the second current value, the current of the plasma current is applied to the plurality of switches with the discharge switch turned off. PWM control is performed based on the difference between the current value and a target value that varies from the first current value toward the second current value, so that the plasma current has a slope that is gentler than the slope at the time of startup in the first period. performs first current control to increase toward the second current value,
In a third period after the plasma current reaches the second current value, the current value of the plasma current and the second current value are changed to the plurality of switches with the discharge switch turned off. A power supply device characterized in that a second current control is performed to maintain the plasma current at the second current value by performing PWM control based on a difference between the plasma current and the plasma current.

interposed between the rising part and the maintaining part, electrically disconnecting the rising part and the maintaining part when in the off state, and disconnecting the rising part and the maintaining part when in the on state; further comprising a connection switch for electrically connecting the
The power supply device according to claim 1, wherein the connection switch is in an OFF state during the constant voltage control, and is in an ON state during the first current control and the second current control.

The control unit includes:
a PWM control unit that performs PWM control on the plurality of switches of the bridge circuit;
a first calculation unit that calculates a difference between the voltage across the output capacitor and the voltage across the discharge capacitor, and outputs a first signal according to the difference;
a second calculation unit that calculates a difference between the current value of the plasma current and a predetermined target current value and outputs a second signal according to the difference;
a control changeover switch that selects the first signal during the first period, selects the second signal during the second period and the third period, and outputs the selected signal to the PWM control unit;
Equipped with
3. The PWM control section performs the constant voltage control based on the first signal, and performs the first current control and the second current control based on the second signal. The power supply described in .

The control unit includes:
a slope generation unit that outputs a third signal for increasing the target current value toward the second current value at a predetermined slope;
a target current setting unit that outputs a fourth signal for setting the target current value to the second current value;
a target current changeover switch that selects the third signal during the second period, selects the fourth signal during the third period, and outputs the selected signal to the second calculation unit as the target current value;
The power supply device according to claim 3, further comprising:.