KR20170105344A - Radio Frequency Power Generation Apparatus - Google Patents

Radio Frequency Power Generation Apparatus

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Publication number
KR20170105344A
KR20170105344A KR1020160028448A KR20160028448A KR20170105344A KR 20170105344 A KR20170105344 A KR 20170105344A KR 1020160028448 A KR1020160028448 A KR 1020160028448A KR 20160028448 A KR20160028448 A KR 20160028448A KR 20170105344 A KR20170105344 A KR 20170105344A
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South Korea
Prior art keywords
load
phase
power
current
lead
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KR1020160028448A
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Korean (ko)
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KR101812735B1 (en
Inventor
손영훈
박세홍
엄세훈
Original Assignee
인투코어테크놀로지 주식회사
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Priority to KR1020160028448A priority Critical patent/KR101812735B1/en
Publication of KR20170105344A publication Critical patent/KR20170105344A/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/46—Generating plasma using applied electromagnetic fields, e.g. high frequency or microwave energy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32082—Radio frequency generated discharge
    • H01J37/32174—Circuits specially adapted for controlling the RF discharge
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/445—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
    • H03H7/38—Impedance-matching networks
    • H05H2001/4645—

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Electromagnetism (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Inverter Devices (AREA)

Abstract

The present invention provides a radio frequency power generation apparatus. The apparatus comprises: a direct current power supply; a switch circuit including a plurality of switches electrically connected to the direct current power supply to change a current path of a load including a load resistor, a load inductor, and a load capacitor; and a control unit for driving the switch circuit by sensing a load current flowing in the load to change a frequency. The control unit autonomously vibrates to adjust the frequency around a serial resonance frequency by the load inductor and the load capacitor.

Description

TECHNICAL FIELD [0001] The present invention relates to a radio frequency power generation apparatus,

The present invention relates to an RF power generator, and more particularly, to a self-oscillating radio frequency power generator that self-adjusts to the resonant frequency of a load in response to a time-varying load.

The inverter can convert the DC input voltage to the AC output voltage. The output voltage and output frequency can be varied. It is mainly controlled by methods such as pulse width modulation or pulse amplitude modulation.

Conventional RF generators output sinusoids at specific frequencies. The output of the RF generator is delivered to the load through an impedance matching network. The impedance matching network performs impedance matching using a variable reactive element to transmit the maximum power of the RF generator to the load.

However, an RF generator outputting a sinusoidal wave of a fixed frequency can not supply stable RF power to the load when the time varying load quickly changes with time.

Therefore, a new method for stably supplying RF power to a time varying load is required.

An aspect of the present invention is to provide an RF power source that operates in the vicinity of a resonance frequency of a load by replacing an impedance matching circuit of a variable reactive element structure with a fixed reactive element and applying a self resonance method.

A radio frequency power generator according to an embodiment of the present invention includes a DC power source; A switch circuit including a plurality of switches electrically connected to the direct current power source for changing a current path from the direct current power source to a load including a load resistance, a load inductor and a load capacitor; And a controller for sensing the load current flowing through the load and changing the frequency to drive the switch circuit. The control unit may self-oscillate to adjust the frequency around the series resonance frequency by the load inductor and the capacitor.

In one embodiment of the present invention, the control unit includes a primary coil and a secondary coil, one end of the secondary coil is grounded, and a current transformer detects a load current of the load; A resistive resistor connected to the secondary coil of the current transformer; A lead sensing circuit that is connected in parallel to the resistive resistor and includes a lead capacitor, a lead inductor, and a lead variable resistor connected in series to each other and provides a leading phase; A negative input connected to the ground and a positive input coupled to the lead inductor in series and a lead voltage signal applied to the lead variable resistor; A switch driver receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And a power control unit for controlling the read variable resistor by comparing a load power and a set reference power transmitted to the load.

In one embodiment of the present invention, when the phase of the load current with respect to the load voltage is fast, the control unit may decrease the lead variable resistance.

In one embodiment of the present invention, when the set power is larger than the load power, the lead variable resistance may increase.

In one embodiment of the present invention, when the set power is smaller than the load power, the lead variable resistance can be reduced.

The power control unit may further include a flip-flop that receives the load current as an input and receives an opposite sign of the switching driving signal as a clock signal and outputs the clock signal to an output terminal. The flip- And the lead variable resistance can be reduced when the signal at the output terminal is LOW.

In one embodiment of the present invention, the switch circuit may be a voltage type half-bridge inverter, a voltage type full-bridge inverter, a current type half-bridge inverter, or a current type full-bridge inverter.

In one embodiment of the present invention, the control unit includes a current transformer including a primary coil and a secondary coil and sensing the load current; A resistive resistor connected to the secondary coil of the current transformer; A comparator for comparing a ground voltage signal and a ground voltage signal between the ground and the resistive resistor; A time delay providing a time delay for providing a time delay by receiving an output signal of the comparator; A switch driver for receiving the output signal of the time delay providing unit and generating the switch driving signal with an additional phase delay; And a power controller for controlling the time delay by comparing the load power and the set reference power delivered to the load.

In one embodiment of the present invention, the control unit includes a lead capacitor, a lead inductor, and a lead variable resistor connected in parallel to the resistance of resistance to the secondary side of the current transformer and connected in series with each other, And a leading sensing circuit for providing a leading phase in advance. The power control unit may control the leading phase by comparing the load power and the reference power supplied to the load.

In one embodiment of the present invention, the control unit includes a primary coil and a secondary coil, one end of the secondary coil is grounded, and a current transformer detects a load current of the load; A resistive resistor connected to the secondary coil of the current transformer; A lead sensing circuit including a lead capacitor, a lead inductor, and a lead variable resistor connected in parallel to the secondary coil of the current transformer and connected in series, and providing a leading phase; A negative input coupled to the ground and a positive input coupled to the lead variable resistor or a read voltage signal applied to the lead inductor; A switch driver receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And a power control unit for controlling the read variable resistor by comparing a load power and a set reference power transmitted to the load.

In one embodiment of the present invention, the control unit includes a primary coil and a secondary coil, one end of the secondary coil is grounded, and a current transformer detects a load current of the load; A lead sensing circuit including a lead capacitor connected in series to the secondary coil of the current transformer, a lead inductor, and a lead variable resistor and providing a leading phase; A negative input coupled to the ground and a positive input coupled to a leading voltage signal applied to the lead variable resistor; A switch driver receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And a power control unit for controlling the read variable resistor by comparing a load power and a set reference power transmitted to the load.

In one embodiment of the present invention, the control unit includes a primary coil and a secondary coil, one end of the secondary coil is grounded, and a current transformer detects a load current of the load; A leading sensing circuit including a lead inductor and a lead variable resistor connected to the secondary coil of the current transformer and connected in parallel to each other and providing a leading phase; A negative input coupled to the ground and a positive input coupled to a leading voltage signal applied to the lead variable resistor; A switch driver receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And a power control unit for controlling the read variable resistor by comparing a load power and a set reference power transmitted to the load.

A radio frequency power generator according to an embodiment of the present invention includes a DC power source; A switch circuit including a plurality of switches electrically connected to the direct current power source for changing a current path from the direct current power source to a load including a load resistance, a load inductor and a load capacitor; And a controller for sensing the load current flowing in the load and driving the switch. Wherein the controller detects the load current in real time and keeps the mutual phase between the load current and the load voltage constant by switching the switch with a constant phase from the moment the load current crosses zero, So that the series resonant frequency of the inductor and the load capacitor is automatically followed.

A radio frequency power generator according to an embodiment of the present invention includes a DC power source; A switch including a plurality of switches electrically connected to said direct current power source for changing a current path from said direct current power source to a load including load resistance (R L ), load inductor (L L ) and load capacitor (C L ) Circuit; And a controller for sensing the load current flowing in the load and driving the switch. Wherein the control unit includes: a current transformer for sensing a load current of the load; A resistive resistor connected to the secondary side of the current transformer; And a leading sensing circuit coupled to the secondary of the current transformer. The lead sensing circuit includes a lead capacitor (C) connected in series to a secondary side of the current transformer; And a lead inductor (L) and a lead resistor (R) connected in series between the lead capacitor and the ground.

The control unit

Figure pat00001

Operates at an angular frequency (?) That satisfies the above condition,

The delay time t delay is a delay time generated in order to generate a switch driving signal for driving the switch in the control unit.

In one embodiment of the present invention, when the phase of the load current with respect to the load voltage is fast, the delay time can be reduced.

In an embodiment of the present invention, when the phase of the load current with respect to the load voltage is slow and the set power is larger than the load power, the delay time may increase.

In one embodiment of the present invention, when the phase of the load current with respect to the load voltage is slow and the set power is smaller than the load power, the delay time can be reduced.

In one embodiment of the present invention, the delay time t delay may vary.

In one embodiment of the present invention, the lead resistance R may be a variable resistor.

In one embodiment of the present invention, the lead resistance R can be reduced when the phase of the load voltage is slower than the phase of the load current (negative phase).

In one embodiment of the present invention, if the phase of the load voltage is faster than the phase of the load current (positive phase) and the set reference power is less than the current power, the read resistance R can be reduced .

In one embodiment of the present invention, if the phase of the load voltage is faster than the phase of the load current (positive phase) and the set reference power is greater than the current power, the read resistance R can be increased .

In one embodiment of the present invention, when the phase of the load voltage is faster than the phase of the load current (positive phase), the read resistance R may be increased.

In one embodiment of the present invention, if the phase of the load voltage is slower than the phase of the load current (negative phase) and the set reference power is less than the current power, the read resistance R can be increased .

In one embodiment of the present invention, if the phase of the load voltage is slower than the phase of the load current (negative phase) and the set reference power is greater than the current power, the read resistance R can be reduced .

A self-resonant radio frequency power generator according to an embodiment of the present invention is configured to change a current path from a DC power source to a load including a load resistance (R L ), a load inductor (L L ) and a load capacitor (C L ) And a switch circuit including a plurality of switches electrically connected to the DC power source. The power control method of the self-resonant radio frequency power generator may include sensing a load current flowing in the load and detecting power transmitted to the load; Comparing the phase of the load current generated by the switch driving signal for driving the switch circuit with the phase of the load current; And increasing the phase difference between the switch driving signal for driving the switch circuit and the load current and increasing the driving frequency when the phase of the load voltage is slower than the phase of the load current.

In one embodiment of the present invention, when the phase of the load voltage is faster than the phase of the load current and the set reference power is smaller than the current power, the phase difference between the switch drive signal for driving the switch circuit and the load current And increasing the driving frequency.

In one embodiment of the present invention, when the phase of the load voltage is faster than the phase of the load current and the set reference power is greater than the current power, the phase difference between the switch drive signal for driving the switch circuit and the load current And reducing the driving frequency.

A self-resonant radio frequency power generator according to an embodiment of the present invention is configured to change a current path from a DC power source to a load including a load resistance (R L ), a load inductor (L L ) and a load capacitor (C L ) And a switch circuit including a plurality of switches electrically connected to the DC power source. The power control method of the self-resonant radio frequency power generator may include sensing a load current flowing in the load and detecting power transmitted to the load; Comparing the phase of the load current generated by the switch driving signal for driving the switch circuit with the phase of the load current; And reducing the phase difference between the switch drive signal for driving the switch circuit and the load current and reducing the drive frequency when the phase of the load voltage is faster than the phase of the load current.

In one embodiment of the present invention, when the phase of the load voltage is slower than the phase of the load current and the set reference power is smaller than the current power, the phase difference between the switch drive signal for driving the switch circuit and the load current And reducing the driving frequency.

In one embodiment of the present invention, when the phase of the load voltage is slower than the phase of the load current and the set reference power is larger than the current power, the phase difference between the switch drive signal for driving the switch circuit and the load current And increasing the driving frequency.

The RF power source according to an embodiment of the present invention can stably provide a power of several kW to several tens kW at a time-varying plasma load in the frequency region of several MHz.

The RF power source according to an embodiment of the present invention can provide a fast impedance matching to a time-varying plasma load to drive a large amount of current.

1 is a conceptual diagram illustrating a radio frequency power generator according to an embodiment of the present invention.
2 is an equivalent circuit for explaining the radio frequency power generating apparatus of FIG.
Fig. 3 is a view showing load current and load voltage according to the inductor of the load of Fig. 1; Fig.
4 is a view showing a resonance frequency according to the inductor of the load of FIG.
5 is a graph showing the power consumed by the load according to the inductor of the load of FIG.
6 is a circuit diagram illustrating a radio frequency power generator according to another embodiment of the present invention.
FIG. 7 is a diagram showing signals according to time in FIG. 6. FIG.
8 is a block diagram illustrating a radio frequency power generator according to another embodiment of the present invention.
9 is a view for explaining a leading sensing circuit of the radio frequency power generating apparatus of FIG.
10 and 11 are views showing signals of the radio frequency power generating apparatus of FIG.
12 is a diagram showing power and phase according to the frequency of Fig.
Fig. 13 is a diagram showing power according to a load resistance in the radio frequency power generator of Fig. 8; Fig.
FIG. 14 is a diagram showing a phase according to a lead resistance in the radio frequency power generator of FIG. 8. FIG.
15 is a diagram showing power and phase according to frequency.
16 is a flowchart for explaining a method of operating the radio frequency power generator of FIG.
17 is a view for explaining a power control method according to another embodiment of the present invention.
18 is a flowchart for explaining the power control method of Fig.
FIG. 19 is a view for explaining a phase of a radio frequency power generator according to another embodiment of the present invention with respect to time delay. FIG.
20 is a flowchart for changing the phase according to the time delay of FIG.
21 is a conceptual diagram illustrating a radio frequency power generator employing a full-bridge inverter according to another embodiment of the present invention.
22 is a circuit diagram showing a leading sensing circuit according to another embodiment of the present invention.
23 is a circuit diagram showing a leading sensing circuit according to still another embodiment of the present invention.
24 is a circuit diagram showing a leading sensing circuit according to still another embodiment of the present invention.
25 is a flowchart showing a power control method of a self-resonant radio frequency power generator according to another embodiment of the present invention.

The electrical load characteristics of the plasma source vary greatly depending on the gas pressure, type, flow rate, and the like. Since the impedance matching network is a resonant tank, the change in the characteristics of this plasma source causes a sudden change in power. A conventional method for solving this problem includes a variable capacitor or a variable inductor in an impedance matching network. Such a structure is bulky, increases the complexity of the system, and increases the cost.

According to one embodiment of the present invention, a "self-oscillating method" can be applied to an RF generator to easily solve this problem with a small volume and a low price. Resonance type lead-sensing may be provided to smoothly implement the self-oscillation method at a high frequency of 3 to 5 MHz.

According to one embodiment of the invention, the load may be an inductive load comprising an induction coil that produces an inductively coupled plasma. The load may include a fixed capacitor connected in series as an impedance matching network to configure an LC resonant circuit. When the series LC resonant circuit is formed, the inverter delivers maximum power to the load and the impedance can be matched.

According to a modified embodiment of the present invention, the load may be a capacitive load comprising a charge electrode generating a charge coupled plasma. The load may include a fixed inductor connected in series as an impedance matching network to form an LC resonant circuit. When the series LC resonant circuit is formed, the inverter delivers maximum power to the load and the impedance can be matched.

The inverter includes a pair of switches or choppers. The pair of choppers are controlled not to be turned on at the same time. The control unit senses the load current flowing to the load in real time. When the load current switches a pair of choppers as soon as the load current crosses zero, the load current and load voltage have zero phase, and the operating frequency has a series resonant frequency.

On the other hand, when the series LC load resonance circuit is formed, when the switching driving signal is generated by using the load current, the switching driving signal has a time delay by the logic circuit, Is processed through a leading phase sensing circuitry that provides a read phase. The leading phase may be set to compensate for the time delay caused by the logic circuit or to additionally provide a delay phase.

On the other hand, in order to transmit the set power to the load, the driving frequency (or phase) may be intentionally set to slightly deviate from the resonant frequency of the series LC resonant circuit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following examples and results are provided so that the disclosure of the present invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Also, for convenience of explanation, the components may be exaggerated or reduced in size.

1 is a conceptual diagram illustrating a radio frequency power generator according to an embodiment of the present invention.

2 is an equivalent circuit for explaining the radio frequency power generating apparatus of FIG.

Fig. 3 is a view showing load current and load voltage according to the inductor of the load of Fig. 1; Fig.

4 is a view showing a resonance frequency according to the inductor of the load of FIG.

5 is a graph showing the power consumed by the load according to the inductor of the load of FIG.

1 to 5, a radio frequency power generating apparatus 100 includes a DC power supply 110; And a plurality of switches electrically connected to the direct current power source to change the current path from the direct current power source 110 to the load 131 including the load resistance 134a, the load inductor 134b and the load capacitor 132 A switch circuit (120) for applying a voltage; And a controller 140 for sensing the load current i L (t) flowing through the load 131 and changing the frequency to drive the switch circuit 120. The control unit 140 self-oscillates the frequency around the series resonance frequency of the load inductor 134b and the load capacitor 132 by itself.

Plasma source 134 forms an inductively coupled plasma and can be represented by a load inductor 134b and a load resistor 134a. The load inductor 134b can be time-varying. The load resistor 134a may be time-varying.

According to a modified embodiment of the present invention, the plasma source 134 forms a capacitively coupled plasma and can be represented by a load capacitor and a load resistance. The load capacitor can be time-varying. The load resistance may be time varying.

The impedance matching network may include a fixed load capacitor 132 and may be connected in series to the plasma source 134 to configure an LCR circuit that is cascaded in its entirety. The load 131 may include a fixed capacitor 132 connected in series, a load inductor 134b, and a load resistor 134a.

The DC power supply 110 may include a rectifier 111, a circuit breaker and a noise filter 112, and a pair of capacitors 113. The rectifier 111 may be half-wave rectified or full-wave rectified through a diode rectifier circuit after being supplied with three-phase power. The pair of capacitors 114 are connected to each other in series, one end of the capacitor connected in series may be grounded, and the other end may be connected to a maximum power supply voltage (2V DD ) of several hundreds of volts compared to the ground.

The DC power supply 110 may include a first driving voltage source and a second driving voltage source. The first driving voltage source may provide half of the maximum power supply voltage and the second driving voltage source may provide the other half of the maximum power supply voltage. The second driving voltage source may apply a driving voltage (V DD ) between the ground and the first terminal.

The switch circuit 120 may include a pair of switches 122a and 122b. The switch circuit 120 may be an inverter that changes the direct current to alternating current. The switch circuit may be a half wave bridge inverter or a full wave bridge inverter.

The pair of switches may include a first switch 122a and a second switch 122b. The first switch 122a may include a transistor and a first switch gate driver. The first switch gate driver may switch by providing a first switch gate signal S A to the gate of the transistor.

The second switch 122b may include a transistor and a second switch driver. The second switch gate driver may switch the second switch gate signal S B by providing it to the gate of the transistor.

The pair of switches 122a and 122b may be connected in series between the ground and the maximum power supply voltage (2V DD ).

One terminal of the load 131 is connected to the connection terminal (or the second terminal, N2) of the first switch and the second switch, and the other terminal of the load is connected to the connection terminal of the first drive voltage source and the second drive voltage source 1 terminal, N1). The load 131 may comprise a series connected load capacitor, a variable load inductor, and a variable load resistor. The load capacitor may operate as an impedance matching network.

The first switch 122a and the second switch 122b may be switched when the load current i L (t) flowing in the load passes a zero point. Thus, when maximum power is delivered to the load resistor R, the switching can exactly match the resonant frequency of the load LC circuit. In this case, the load current i L (t) and the load voltage v L (t) may be in phase.

When the load resistance is constant and the inductance of the load inductor changes, the resonant frequency is changed and the switch can be switched according to the resonant frequency. The power transmitted to the load resistor may be constant.

On the other hand, when the load resistance changes, the resonance frequency is constant, but the power consumed in the load resistance can be changed. Accordingly, the driving frequency can be intentionally changed from the resonance frequency in order to keep the power consumed in the load resistance constant.

6 is a circuit diagram illustrating a radio frequency power generator according to another embodiment of the present invention.

FIG. 7 is a diagram showing signals according to time in FIG. 6. FIG.

6 and 7, the radio frequency power generator 100a includes a DC power supply 110; A switch circuit 120 including a plurality of switches electrically connected to the direct current power source to change the current path from the direct current power source to a load including a load resistor 134a, a load inductor 134b and a load capacitor 132, ; And a controller 140 for sensing the load current flowing through the load and changing the frequency to drive the switch circuit 120. The control unit 140 self-oscillates the frequency around the series resonance frequency of the load inductor and the load capacitor.

The control unit 140 includes a current transformer 141 including a primary coil and a secondary coil and detecting a load current of the load. A resistive resistor 142 connected to the secondary coil of the current transformer; A comparator (143) for comparing the voltage signal induced in the resistance to the ground; And a switch driver 144 for receiving the output signal of the comparator and generating the switch driving signal with a phase delay.

The current transformer 141 is disposed between the load 131 and the first terminal N1 and may include a primary coil and a secondary coil. The turns ratio of the current transformer 141 is 1: n, and the number of turns (n) of the secondary coil may be several to several tens. The primary coil of the current transformer may have a structure in which a grounded outer conductor is removed from a coaxial transmission line. The current transformer 141 may have a structure in which a secondary coil is wound around a toroidal magnetic body. The coils of the current transformer may be wound in opposite directions to each other so that the magnetic fluxes are formed in opposite directions to each other.

The resistive resistor 142 may be connected between both ends of the secondary coil of the current transformer. The voltage signal v S (t) induced in the resistance can be proportional to the load current i L (t), the winding n of the secondary coil, and the resistance Rs, .

The comparator 143 may output a HIGH signal when the load current has a positive value and generate a LOW signal when the load current has a negative value.

The switch driver 144 may include a logic circuit for receiving and processing the output signal of the comparator 143. For example, the switch driver 144 may include an isolator and a logic inverter for interrupting the electrical path of the input and the output. The switch driver 144 may cause a time delay. The switch driver 144 may generate a first switch driving signal S A for driving the first switch and a second switch driving signal S B for driving the second switch. The second switch driving signal may be formed by inverting the first switch driving signal.

On the other hand, if the self-oscillation method is applied in a high-frequency state such as 4 MHz, the phases of i L (t) and v L (t) can largely differ from each other due to the processing speed of the switch driver 144.

When a time delay (t delay ) occurs in the switch driver 144, the switch driving signal may not operate in phase with the load current. Thus, the power generation device can not deliver the maximum power to the load. Therefore, there is a need for a leading sensing circuit that operates the switch driving signal (S A , S B ) in phase with the load current or changes the phase to provide a desired phase.

8 is a block diagram illustrating a radio frequency power generator according to another embodiment of the present invention.

9 is a view for explaining a leading sensing circuit of the radio frequency power generating apparatus of FIG.

10 and 11 are views showing signals of the radio frequency power generating apparatus of FIG.

12 is a diagram showing power and phase according to the frequency of Fig.

Fig. 13 is a diagram showing power according to a load resistance in the radio frequency power generator of Fig. 8; Fig.

FIG. 14 is a diagram showing a phase according to a lead resistance in the radio frequency power generator of FIG. 8. FIG.

15 is a diagram showing power and phase according to frequency.

16 is a flowchart for explaining a method of operating the radio frequency power generator of FIG.

8 to 16, the radio frequency power generator 200 includes a DC power supply 110; A switch circuit (120) including a plurality of switches electrically connected to the direct current power source to change a current path from the direct current power source to a load (131) including a load resistance, a load inductor and a load capacitor; And a controller 240 for sensing the load current flowing through the load and changing the frequency to drive the switch circuit. The controller 240 self-oscillates the frequency around the series resonance frequency of the load inductor and the load capacitor.

The control unit 240 includes a transformer 141, which includes a primary coil and a secondary coil, one end of the secondary coil is grounded, and a load current of the time-varying load is sensed; A resistive resistor 142 connected to the secondary side of the current transformer; A lead sensing circuit 244a including a lead capacitor 244a, a lead inductor 244b and a lead variable resistor 244c connected in parallel to the resistive resistance 142 and providing a leading phase, ); A negative input terminal connected to the ground and a positive input terminal connected in series to the lead inductor 244b and a comparator 143 connected to the lead voltage signal V SL (t) applied to the lead variable resistor 244c; A switch driver 245 receiving the output signal of the comparator 143 and generating the switch driving signals S A and S B with a phase delay t delay ; And a power control unit 248 for controlling the read variable resistor by comparing the load power and set reference power transmitted to the load.

The current transformer 141 is disposed between the load 131 and the first terminal N1 and may include a primary coil and a secondary coil. The turns ratio of the current transformer 141 is 1: n, and the number of turns (n) of the secondary coil may be several to several tens. The primary coil of the current transformer may have a structure in which a grounded outer conductor is removed from a coaxial transmission line. The current transformer 141 may have a structure in which a secondary coil is wound around a toroidal magnetic body. The coils of the current transformer may be wound in opposite directions to each other so that the magnetic fluxes are formed in opposite directions to each other. One end of the secondary coil of the current transformer may be grounded.

The resistance 142 may be connected between both ends of the secondary coil of the current transformer 141. The voltage signal v S (t) induced in the resistance can be proportional to the load current i L , the resistance R s, and the winding n of the secondary of the current transformer.

The lead sensing circuit 244 may include a lead capacitor 244a, a lead inductor 244b, and a lead variable resistor 244c which are connected in parallel to the resistance resistor 142 and are connected in series with each other. Both ends of the circuit composed of the lead inductor 244b and the lead resistor 244c connected in series to each other can be connected to the positive input and the negative input of the comparator 143, respectively. The reading voltage signal v SL may be a signal at the connection terminal N3 of the lead capacitor 244a and the lead inductor 244b. The reading voltage signal v SL may have a leading phase.

The read phase can be expressed as:

Figure pat00002

The reading sensing circuit 244 may have a lead time based on a zero point at which the load current changes from a negative value to a positive value. The lead time (t lead ) may be proportional to the leading phase.

The comparator 143 receives the leading voltage signal v SL as a positive input and receives the ground signal as a negative input and outputs a high level signal when the leading voltage signal v SL has a positive value. And outputs a low signal when the reading voltage signal v SL has a negative value. Accordingly, the time at which the output signal of the comparator 143 is changed from the LOW state to the HIGH state is determined based on the zero point at which the load current is changed from the negative value to the positive value, t lead ) or a leading phase.

The output signal of the comparator 143 may be provided to the switch driver 245. The switch driver 245 may include a pair of isolators. The output signal of the comparator may be branched and provided to a first isolator 246a and a second isolator 246b.

The output signal of the first isolator 246a is provided to the logic buffer circuit 247 and the output signal of the second isolator 246b is provided to the logic inverter circuit 247. [ The output of the logic buffer circuit 247a is provided to the first switch gate driver 124a of the first switch 122a and the output of the logic inverter circuit 247b is provided to the second switch gate 224b of the second switch 122b, And is provided to the driving unit 124b. The switch driver 245 may generate a time delay t delay . The time delay t delay may be changed from a low state to a high state by a time when the output of the comparator changes from a LOW state to a HIGH state, Lt; RTI ID = 0.0 > time. ≪ / RTI >

If the time delay t delay and the read time t lead are the same, the output signal S A of the gate driver 124a of the first switch may be in the same phase. The output signal S B of the gate driver 124b of the second switch may be the opposite signal of the output signal S A of the gate driver of the first switch.

If the time delay t delay is greater than the lead time t lead , the phase of the load voltage may be faster than the phase of the load current.

The output of the comparator 143 may be provided to a time delay providing unit 249 which provides an additional time delay for the time delay t delay . Accordingly, the time delay providing unit 249 can control the power and the driving frequency by changing the time delay t delay without varying the lead variable resistor 244c.

The load 131 constitutes a series LC resonance circuit. Thus, depending on the drive frequency, the power consumed in the load resistor has a maximum at the resonant frequency. In addition, the phase of the LC resonant circuit has an arctan function form according to the driving frequency. At the resonant frequency, the phase of the LC load resonant circuit may be zero.

On the other hand, the lead sensing circuit constitutes a series resonance circuit and provides a leading phase, and the leading phase can be approximated to a straight line having a negative slope according to the driving frequency.

Therefore, the driving frequency can be determined at a point where the phase of the LC load resonance circuit and the leading phase of the leading sensing circuit cross each other.

If the switch driver includes a time delay (t delay ), the driving frequency under the resonance condition may satisfy the following condition.

Figure pat00003

Where L is the inductance of the load inductor, C L is the capacitance of the load capacitor, and R L is the load resistance. L is the inductance of the lead inductor, C is the capacitance of the lead capacitor, and R is the resistance value of the lead variable resistor. t delay is the time delay of the switch driver.

For example, the unknown may be the driving angular frequency and the lead variable resistance. Therefore, the driving angular frequency and the lead variable resistance satisfying the above conditions can be determined.

For example, the unknown may be the driving angular frequency and time delay. Therefore, the driving angular frequency and time duration satisfying the above conditions can be determined.

In the above equations, the first term is the phase due to the load resonant circuit, the second term and the third term are the phase by the leading sensing circuit, and the last term is the phase due to the time delay.

Referring to Fig. 12 (c), when the lead resistance R is variable, when the lead resistance R increases, the y-axis intercept of the phase can be reduced. The lead resistance can be changed so that the phase of the LC load resonance circuit becomes zero. This allows the load to operate at the LC resonant frequency and deliver maximum power to the load.

Referring to FIG. 13, when the load resistance R L is time-varying, the output power decreases in inverse proportion as the load resistance increases. The solid line is when the resonance condition is satisfied. The dotted line indicates the case where the resonance condition is not satisfied.

When the present reference position power satisfies the resonance condition, the phase is changed so as not to satisfy the resonance condition, and the reference reference power (B point) is set to the reference reference power (P REF ) Can reach. To this end, the lead variable resistor R decreases, thereby increasing the drive frequency and increasing the phase.

On the other hand, if the load resistance R L increases and the set reference power P REF is greater than the current power (point C), if the current position does not meet the resonance condition, the phase is changed to meet the resonance condition, Can be operated to approach the set reference power as much as possible at the condition (point D). To this end, the lead variable resistor R increases, thereby reducing the driving frequency and decreasing the phase.

Referring to Equation (2), the total phase difference is represented by the phase of the load, the leading phase of the leading sensing circuit, and the phase due to the time delay.

Referring to Fig. 14, if the phase of the load has a positive value, the phase of the load voltage is faster than the phase of the load current. On the other hand, if the phase of the load has a negative value, the phase of the load voltage is slower than the phase of the load current. The sign of the phase of the load is the load current i L (t) and the switch drive signal

Figure pat00004
)).

If the phase of the load has a negative value, the lead resistance R is decreased and moved to the positive phase region. When the lead resistance is reduced, the phase of the load increases and the driving frequency is increased.

15 and 16, if the phase of the load has a positive value, it can operate in the first mode and the second mode. That is, the first mode (point A-B) is a case where the current power is larger than the set reference power. In the first mode, the phase of the load is artificially increased to deviate from the resonance condition. The phase of the load changes until the current power is equal to the set reference power. Specifically, when the lead resistance R is reduced, the phase of the load increases, and the drive frequency increases.

 The second mode (point C-D) is when the current power is smaller than the set reference power. In the second mode, the phase of the load is artificially reduced so as to approximate the resonance condition. The phase of the load is changed until the current power reaches the set reference power maximum. Specifically, when the lead resistance R is increased, the phase of the load decreases and the driving frequency decreases.

The power control unit 248 receives the load current i L (t) at an input terminal D and inverts the switching drive signal S A

Figure pat00005
And a flip-flop 248c receiving the clock signal and outputting the clock signal to an output terminal. And the lead variable resistor R may be reduced when the signal of the output terminal of the flip-flop is LOW. The input terminal (D) of the flip-flop is supplied with a load current, and the clock (CLOCK) of the flip-flop is inverted
Figure pat00006
) Can be provided. That is, inversion of the gate driving signal of the first switch
Figure pat00007
Is a gate driving signal of the first switch
Figure pat00008
) Is turned off, the state of the load current can be outputted. The flip-flop can sense the phase of the load current with respect to the load voltage. When the output Q of the D-flip-flop is in the HIGH state, the phase of the load voltage is faster than the phase of the load current. That is, the phase of the load has a positive value.

On the other hand, when the output Q of the D-flip-flop is in the LOW state, the phase of the load voltage is slower than the phase of the load current. That is, the phase of the load has a negative value.

The power control unit 248 may include a power comparator 248a. The power comparator 248a receives the set reference power P REF as a negative input and receives the current power P L as a positive input. When the current power is greater than the set reference power, Status can be output. The current power P L can be measured by the power measuring unit 113. The power measuring unit 113 may be disposed between the DC power supply 110 and the switching circuit 120.

The output of the power comparator 248a may be provided to the auxiliary power control unit 248b. The auxiliary power controller 248b may be a field programmable gate array (FPGA). When the output signal of the flip-flop is received and the phase of the load is negative, the auxiliary power control unit 248b decreases the read resistance R and moves the positive phase region to the positive phase region. When the lead resistance R is reduced, the phase of the load increases, and the driving frequency is increased.

The auxiliary power control unit 248b may be operated in any one of the first mode and the second mode when the output signal of the flip-flop 248c is received and the load has a positive value. The first mode (point A-B) is a case where the current power is larger than the set reference power. In the first mode, the phase of the load is artificially increased to deviate from the resonance condition. The phase of the load changes until the current power is equal to the set reference power. Specifically, when the lead resistance is reduced, the phase of the load increases, and the drive frequency increases. The second mode (point C-D) is when the current power is smaller than the set reference power. In the second mode, the phase of the load is artificially reduced so as to approximate the resonance condition. The phase of the load is changed until the current power reaches the set reference power maximum. Specifically, when the lead resistance is increased, the phase of the load decreases and the drive frequency decreases.

Hereinafter, an operation method of a self-resonant radio frequency power generator is disclosed.

The self-resonant radio frequency power generator 200 is the order to change the current path for the load comprising a direct current power source 110, a load resistance (R L), the load inductor (L L) and from the load capacitor (C L) And a switch circuit (120) including a plurality of switches electrically connected to the DC power source. The self-resonant radio frequency power generator 200 receives the set reference power P REF from the outside and has a set delay time t delay (S110).

The current transformer 141 senses the load current IL (t) flowing through the load and the power measuring unit 113 senses the power P L (t) transmitted to the load (S112).

The flip-flop 248c includes a switch driving signal ((

Figure pat00009
And compares the phase of the load current i L (t) with the phase of the load voltage v L (t) generated by the load current v L (t) (S115).

When the phase of the load voltage is slower than the phase of the load current (S115), the power control unit 248 increases the phase difference between the switch driving signal for driving the switch circuit and the load current and increases the driving frequency. Specifically, the power control unit 248 may control the lead variable resistance 244c of the leading phase sensing unit 244 to be reduced. Accordingly, the phase is increased and the driving frequency is increased so that the phase of the load has a positive value (S116). Then, the control unit 240 generates the switch driving signals S A and S B.

When the phase of the load voltage is faster than the phase of the load current (S115) and the set reference power is smaller than the current power (S117), the power control unit 248 controls the switch control unit 248 to switch between the switch drive signal for driving the switch circuit and the load current And increases the driving frequency. Specifically, the power control unit 248 may control the lead variable resistor 244c of the leading phase sensing unit to decrease. Accordingly, the phase difference is increased and the driving frequency is increased to reduce the current power (S119). Then, the control unit 240 generates the switch driving signals S A and S B.

When the phase of the load voltage is higher than the phase of the load current (S115) and the setting reference power is larger than the current power (S117), the power control unit 248 controls the switch control unit 248 to switch between the switch driving signal for driving the switch circuit and the load current And decreases the driving frequency. Specifically, the power control unit 248 may control the lead variable resistance of the leading phase sensing unit to increase. Accordingly, the phase difference is decreased and the driving frequency is decreased to increase the current power (S118). Then, the control unit 240 generates the switch driving signals S A and S B.

17 is a view for explaining a power control method according to another embodiment of the present invention.

18 is a flowchart for explaining the power control method of Fig. A description overlapping with that described in Fig. 16 will be omitted.

Referring to FIGS. 17 and 18, the power decreases inversely as V 2 / R increases the load resistance. If the phase of the load voltage is faster than the phase of the load current in step S115 and the current power is smaller than the set reference power in step S117, the power can be controlled by increasing the applied voltage V DD of the direct current power supply in step S118a.

Then, the second mode is a case where the current power is smaller than the set reference power. In the case of the second mode, the phase of the load is artificially reduced and changed so as to approach the resonance condition (S118). The phase of the load is changed until the current power reaches the set reference power maximum. Specifically, when the lead resistance is increased, the total phase is decreased and the driving frequency is decreased.

FIG. 19 is a view for explaining a phase of a radio frequency power generator according to another embodiment of the present invention with respect to time delay. FIG.

20 is a flowchart for changing the phase according to the time delay of FIG. A description overlapping with that described in Fig. 8 will be omitted.

Referring to FIGS. 19 and 20, the radio frequency power generating apparatus according to the present embodiment is similar to the radio frequency power generating apparatus described with reference to FIG. In order to change the driving frequency, the delay time providing section may vary the delay time t delay and supply power without using the lead variable resistor of the leading sensing circuit.

The radio frequency power generator 200 includes a DC power source; A plurality of switches electrically connected to the direct-current power supply to change the current path for a time varying load including a time-varying load resistance (R L), the time-varying load inductor (L L) and a load capacitor (C L) from said DC power supply A switch circuit comprising; And a controller for sensing the load current flowing in the time-varying load to drive the switch. Wherein the control unit comprises: a current transformer for detecting a load current of the time-varying load; A resistive resistor connected to the secondary side of the current transformer; And a leading sensing circuit coupled to the secondary of the current transformer. The lead sensing circuit includes a lead capacitor (C) connected in series to a secondary side of the current transformer; And a lead inductor (L) and a lead resistor (R) connected in series between the lead capacitor and the ground.

The control unit

Figure pat00010

It operates at each frequency (ω) that satisfies the above conditions. The delay time t delay may be a delay time generated in order to generate a switch driving signal for driving the switch in the control unit.

If the phase of the load current with respect to the load voltage is high (S115), the delay time is decreased (S216). Thus, the phase of the load increases, and the driving frequency increases.

If the set reference power is larger than the load power (S117), the delay time is increased (S218).

When the set reference power is smaller than the load power (S117), the delay time is decreased (S219). Thus, the phase of the load increases, and the driving frequency increases.

The delay time t delay may be varied by the delay time providing unit 249.

According to a modified embodiment of the present invention, the lead resistance R can further change the phase of the load using a variable resistor.

21 is a conceptual diagram illustrating a radio frequency power generator employing a full-bridge inverter according to another embodiment of the present invention.

21, the radio frequency power generator includes a DC power source; A switch circuit including a plurality of switches electrically connected to the DC power source to change a current path from the DC power source to a time-varying load including a time-varying load resistance, a time-varying load inductor, and a load capacitor; And a control unit for sensing the load current flowing in the time-varying load and changing the frequency to drive the switch circuit. The control unit self-oscillates the frequency around the series resonance frequency by the time-varying load inductor and the load capacitor.

The DC power supply 210 may include a rectifier, a circuit breaker, and a noise filter. The rectifier may be half-wave rectified or full-wave rectified through a diode rectifier circuit after being supplied with three-phase power. The DC power supply may be connected to a maximum power supply voltage (V DD ) of several hundreds of volts relative to the ground.

The switch circuit 320 may be a voltage type full bridge inverter. The switch circuit includes first to fourth switches. The first switch and the second switch may be connected to each other in series between the ground and the power terminal. The second switch may be connected to ground.

Further, the third switch and the fourth switch may be connected to each other in series between the ground and the power supply terminal. The fourth switch may be connected to the ground.

Each of the first to fourth switches 320a to 320d may include a transistor and a gate driver.

The load 131 may be connected between the connection end N1 of the first switch and the second switch and the connection end N2 of the third switch and the fourth switch.

The first switch 320a and the fourth switch 320d may be simultaneously driven by the first switch driving signal S A. It said second switch (320b) and said fourth switch (320d) can be driven at the same time by the second switch drive signal (S B).

The power control method is the same as that described in the above embodiment.

According to a modified embodiment of the present invention, the switch circuit 320 can be modified into an electric current type half bridge inverter or a current type full bridge inverter.

22 is a circuit diagram showing a leading sensing circuit according to another embodiment of the present invention.

Referring to FIG. 22, a radio frequency power generator 100 includes a DC power supply 110; And a plurality of switches electrically connected to the direct current power source to change the current path from the direct current power source 110 to the load 131 including the load resistance 134a, the load inductor 134b and the load capacitor 132 A switch circuit (120) for applying a voltage; And a controller 140 for sensing the load current i L (t) flowing through the load 131 and changing the frequency to drive the switch circuit 120. The control unit 340 self-oscillates the frequency around the series resonance frequency of the load inductor 134b and the load capacitor 132 by itself.

The control unit 340 includes a primary coil and a secondary coil, one end of the secondary coil is grounded, and a current transformer 141 for sensing a load current of the load; A resistive resistor (142) connected to the secondary coil of the current transformer; A leading sensing circuit 344 including a lead capacitor 344a, a lead inductor 344b and a lead variable resistor 344c connected in parallel to the secondary coil of the current transformer and providing a leading phase; A negative input terminal connected to said ground and a positive input terminal connected to said lead variable resistor or a read voltage signal applied to said lead inductor; A switch driver 245 receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And a power control unit 248 for controlling the read variable resistor by comparing the load power and set reference power transmitted to the load.

Referring again to Figure 9, the resistive resistance and the LRC series circuit are connected to the secondary of the current transformer, and both ends of the LR are connected to the comparator. This connection leads to a phase of the load current, which can be greater than 90 degrees. Therefore, even if the predetermined time delay by the switch driving unit disposed at the rear end of the comparator is large, the load voltage can provide a positive phase faster than the load current.

Referring to FIG. 22, when not necessarily requiring a phase of 90 degrees or more, both ends of the lead variable resistor are connected to the comparator and can provide a reading phase. According to a modified embodiment of the present invention, the leading phase can be connected to both ends of the lead inductor to the comparator.

23 is a circuit diagram showing a leading sensing circuit according to still another embodiment of the present invention.

Referring to FIG. 23, the radio frequency power generator 100 includes a DC power supply 110; And a plurality of switches electrically connected to the direct current power source to change the current path from the direct current power source 110 to the load 131 including the load resistance 134a, the load inductor 134b and the load capacitor 132 A switch circuit (120) for applying a voltage; And a controller 140 for sensing the load current i L (t) flowing through the load 131 and changing the frequency to drive the switch circuit 120. The control unit 440 self-oscillates the frequency around the series resonance frequency of the load inductor 134b and the load capacitor 132 by itself.

The control unit 440 includes a primary coil and a secondary coil, one end of the secondary coil is grounded, and a current transformer 141 for sensing a load current of the load; A leading sensing circuit 444 including a lead capacitor 444a, a lead inductor 444b and a lead variable resistor 444c connected to the secondary coil of the current transformer and connected in parallel to each other and providing a leading phase; A comparator (143) having a negative input terminal connected to said ground and a positive input terminal connected to a leading voltage signal applied to said lead variable resistor; A switch driver 245 receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And a power control unit 248 for controlling the read variable resistor by comparing the load power and set reference power transmitted to the load.

24 is a circuit diagram showing a leading sensing circuit according to still another embodiment of the present invention.

Referring to FIG. 24, a radio frequency power generation apparatus 100 includes a DC power supply 110; And a plurality of switches electrically connected to the direct current power source to change the current path from the direct current power source 110 to the load 131 including the load resistance 134a, the load inductor 134b and the load capacitor 132 A switch circuit (120) for applying a voltage; And a controller 140 for sensing the load current i L (t) flowing through the load 131 and changing the frequency to drive the switch circuit 120. The control unit 540 self-oscillates the frequency around the series resonance frequency of the load inductor 134b and the load capacitor 132 by itself.

The control unit 540 includes a primary coil and a secondary coil, one end of the secondary coil is grounded, and a current transformer 141 for sensing a load current of the load; A leading sensing circuit 544 including a lead inductor 544b and a lead variable resistor 544c connected to the secondary coil of the current transformer and connected in parallel to each other and providing a leading phase; A comparator (143) having a negative input terminal connected to said ground and a positive input terminal connected to a leading voltage signal applied to said lead variable resistor; A switch driver 245 receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And a power control unit 248 for controlling the read variable resistor by comparing the load power and set reference power transmitted to the load.

25 is a flowchart showing a power control method of a self-resonant radio frequency power generator according to another embodiment of the present invention.

25, a self-resonant radio frequency power generator is connected to the load (R L ), the load inductor (L L ), and the load capacitor (C L ) And a switch circuit including a plurality of switches electrically connected to the DC power source. The power control method of the self-resonant radio frequency power generator may include sensing a load current flowing through the load and sensing power transmitted to the load (S112); (S215) comparing a phase of the load current generated by the switch driving signal for driving the switch circuit with the phase of the load current; And decreasing the phase difference between the switch driving signal for driving the switch circuit and the load current and decreasing the driving frequency when the phase of the load voltage is faster than the phase of the load current (S216).

Referring again to FIG. 14, the lead variable resistance (or time delay) can be reduced so as to have a positive phase when the phase of the load is in the negative phase to operate in the positive region (inductive region).

Referring again to FIG. 25, the read variable resistor (or time delay) can be increased to have a negative phase when the phase of the load is a positive phase so as to operate in the negative region (the capacitive region) (S216 ).

Decreasing the phase difference between the switch drive signal for driving the switch circuit and the load current and decreasing the drive frequency when the phase of the load voltage is slower than the phase of the load current and the set reference power is smaller than the current power (S219). That is, when the lead variable resistor is increased in the first mode, the phase decreases and the drive frequency decreases.

Increasing the phase difference between the switch drive signal for driving the switch circuit and the load current and increasing the drive frequency when the phase of the load voltage is slower than the phase of the load current and the set reference power is greater than the current power (S218). That is, when the lead variable resistor is reduced in the second mode, the phase increases and the drive frequency increases.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. And all of the various forms of embodiments that can be practiced without departing from the spirit of the invention.

100; Radio frequency power generator
110: DC power source
120: Switch circuit
131: Load
132: Load Capacitor
134a: Load resistance
134b: Load inductor
120: Switch circuit
140:

Claims (31)

DC power supply;
A switch circuit including a plurality of switches electrically connected to the direct current power source for changing a current path from the direct current power source to a load including a load resistance, a load inductor and a load capacitor; And
And a control unit for sensing the load current flowing in the load and changing the frequency to drive the switch circuit,
Wherein the control unit self-oscillates the frequency to self-align around a series resonance frequency by the load inductor and the capacitor. The method according to claim 1,
The control unit includes:
A current transformer including a primary coil and a secondary coil, one end of the secondary coil being grounded and detecting a load current of the load;
A resistive resistor connected to the secondary coil of the current transformer;
A lead sensing circuit that is connected in parallel to the resistive resistor and includes a lead capacitor, a lead inductor, and a lead variable resistor connected in series to each other and provides a leading phase;
A negative input connected to the ground and a positive input coupled to the lead inductor in series and a lead voltage signal applied to the lead variable resistor;
A switch driver receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And
And a power controller for controlling the read variable resistor by comparing the load power and the reference power supplied to the load. 3. The method of claim 2,
The control unit includes:
And decreases the read variable resistor when the phase of the load current with respect to the load voltage is fast. The method according to claim 2 or 3,
And when the set power is greater than the load power, the lead variable resistance increases. The method according to claim 2 or 3,
And when the set power is smaller than the load power, the lead variable resistance is reduced. 3. The method of claim 2,
The power control unit includes:
And a flip-flop which receives the load current as an input and receives the clock signal of the opposite sign of the switching drive signal and outputs the clock signal to an output terminal,
And reduces the read variable resistor when the signal at the output terminal of the flip-flop is LOW. The method according to claim 1,
Wherein the switch circuit is a voltage type half-bridge inverter, a voltage type full-bridge inverter, a current type half-bridge inverter, or a current type full-bridge inverter. The method according to claim 1,
The control unit includes:
A current transformer including a primary coil and a secondary coil and detecting the load current;
A resistive resistor connected to the secondary coil of the current transformer;
A comparator for comparing a ground voltage signal and a ground voltage signal between the ground and the resistive resistor;
A time delay providing a time delay for providing a time delay by receiving an output signal of the comparator;
A switch driver for receiving the output signal of the time delay providing unit and generating the switch driving signal with an additional phase delay; And
And a power controller for controlling the time delay by comparing the load power and the reference power supplied to the load. 9. The method of claim 8,
The control unit includes:
A lead inductor and a lead variable resistor connected to the secondary side of the current transformer in parallel to the resistance for current change, a lead capacitor connected in series to each other, a lead inductor and a lead variable resistor, Sensing circuit,
Wherein the power control unit controls the leading phase by comparing the load power and the set reference power delivered to the load. The method according to claim 1,
The control unit includes:
A current transformer including a primary coil and a secondary coil, one end of the secondary coil being grounded and detecting a load current of the load;
A resistive resistor connected to the secondary coil of the current transformer;
A lead sensing circuit including a lead capacitor, a lead inductor, and a lead variable resistor connected in parallel to the secondary coil of the current transformer and connected in series, and providing a leading phase;
A negative input coupled to the ground and a positive input coupled to the lead variable resistor or a read voltage signal applied to the lead inductor;
A switch driver receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And
And a power controller for controlling the read variable resistor by comparing the load power and the reference power supplied to the load. The method according to claim 1,
The control unit includes:
A current transformer including a primary coil and a secondary coil, one end of the secondary coil being grounded and detecting a load current of the load;
A lead sensing circuit including a lead capacitor connected in series to the secondary coil of the current transformer, a lead inductor, and a lead variable resistor and providing a leading phase;
A negative input coupled to the ground and a positive input coupled to a leading voltage signal applied to the lead variable resistor;
A switch driver receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And
And a power controller for controlling the read variable resistor by comparing the load power and the reference power supplied to the load. The method according to claim 1,
The control unit includes:
A current transformer including a primary coil and a secondary coil, one end of the secondary coil being grounded and detecting a load current of the load;
A leading sensing circuit including a lead inductor and a lead variable resistor connected to the secondary coil of the current transformer and connected in parallel to each other and providing a leading phase;
A negative input coupled to the ground and a positive input coupled to a leading voltage signal applied to the lead variable resistor;
A switch driver receiving the output signal of the comparator and generating the switch driving signal with a phase delay; And
And a power controller for controlling the read variable resistor by comparing the load power and the reference power supplied to the load. DC power supply;
A switch circuit including a plurality of switches electrically connected to the direct current power source for changing a current path from the direct current power source to a load including a load resistance, a load inductor and a load capacitor; And
And a controller for sensing the load current flowing in the load to drive the switch,
Wherein the controller detects the load current in real time and keeps the mutual phase between the load current and the load voltage constant by switching the switch with a constant phase from the moment the load current crosses zero, To automatically follow the series resonant frequency of the inductor and the load capacitor. DC power supply;
A switch including a plurality of switches electrically connected to said direct current power source for changing a current path from said direct current power source to a load including load resistance (R L ), load inductor (L L ) and load capacitor (C L ) Circuit; And
And a controller for sensing the load current flowing in the load to drive the switch,
The control unit includes:
A current transformer for detecting a load current of the load;
A resistive resistor connected to the secondary side of the current transformer; And
And a leading sensing circuit connected to the secondary side of the current transformer,
The reading sensing circuit comprises:
A lead capacitor (C) connected in series to the secondary side of the current transformer; And
And a lead inductor (L) and a lead resistor (R) connected in series between the lead capacitor and the ground,
The control unit
Figure pat00011

Operates at an angular frequency (?) That satisfies the above condition,
Wherein the delay time t delay is a delay time generated in order to generate a switch driving signal for driving the switch in the control unit. 15. The method of claim 14,
And decreases the delay time when the phase of the load current with respect to the load voltage is fast. 15. The method of claim 14,
Wherein the delay time increases when the phase of the load current with respect to the load voltage is slow and the set power is greater than the load power. 15. The method of claim 14,
Wherein when the phase of the load current with respect to the load voltage is slow and the set power is smaller than the load power, the delay time is reduced. 15. The method of claim 14,
Wherein the delay time (t delay ) is variable. 15. The method of claim 14,
Wherein the lead resistance (R) is a variable resistor. 20. The method of claim 19,
And decreases the read resistance (R) when the phase of the load voltage is slower than the phase of the load current (negative phase). 21. The method of claim 20,
When the phase of the load voltage is faster than the phase of the load current (positive phase) and the set reference power is smaller than the current power,
Thereby reducing the lead resistance (R). 21. The method of claim 20,
If the phase of the load voltage is faster than the phase of the load current (positive phase) and the set reference power is greater than the current power,
And increases the lead resistance (R). 20. The method of claim 19,
And increases the read resistance (R) when the phase of the load voltage is faster than the phase of the load current (positive phase). 23. The method of claim 23,
When the phase of the load voltage is slower than the phase of the load current (negative phase) and the set reference power is smaller than the current power,
And increases the lead resistance (R). 24. The method of claim 23,
If the phase of the load voltage is slower than the phase of the load current (negative phase) and the set reference power is greater than the current power,
Thereby reducing the lead resistance (R). A switch circuit comprising a plurality of switches electrically connected to said direct current power source for changing a current path from a direct current power source to a load including load resistance (R L ), load inductor (L L ) and load capacitor (C L ) A method of controlling power of a self-resonant radio frequency power generator,
Sensing a load current flowing in the load and sensing power transmitted to the load;
Comparing the phase of the load current generated by the switch driving signal for driving the switch circuit with the phase of the load current; And
And increasing the phase difference between the switch drive signal for driving the switch circuit and the load current and increasing the drive frequency when the phase of the load voltage is slower than the phase of the load current. Method of power control of radio frequency power generator. 27. The method of claim 26,
Increasing the phase difference between the switch drive signal for driving the switch circuit and the load current and increasing the drive frequency when the phase of the load voltage is faster than the phase of the load current and the set reference power is less than the current power Further comprising the steps of: generating a self-resonant radio frequency power; 27. The method of claim 26,
Reducing the phase difference between the switch drive signal for driving the switch circuit and the load current and decreasing the drive frequency when the phase of the load voltage is faster than the phase of the load current and the set reference power is greater than the current power Further comprising the steps of: generating a self-resonant radio frequency power; A switch circuit comprising a plurality of switches electrically connected to said direct current power source for changing a current path from a direct current power source to a load including load resistance (R L ), load inductor (L L ) and load capacitor (C L ) A method of controlling power of a self-resonant radio frequency power generator,
Sensing a load current flowing in the load and sensing power transmitted to the load;
Comparing the phase of the load current generated by the switch driving signal for driving the switch circuit with the phase of the load current; And
And reducing the phase difference between the switch drive signal for driving the switch circuit and the load current and reducing the drive frequency when the phase of the load voltage is faster than the phase of the load current. Method of power control of radio frequency power generator. 30. The method of claim 29,
Decreasing the phase difference between the switch drive signal for driving the switch circuit and the load current and decreasing the drive frequency when the phase of the load voltage is slower than the phase of the load current and the set reference power is smaller than the current power Further comprising the steps of: generating a self-resonant radio frequency power; 30. The method of claim 29,
Increasing the phase difference between the switch drive signal for driving the switch circuit and the load current and increasing the drive frequency when the phase of the load voltage is slower than the phase of the load current and the set reference power is greater than the current power Further comprising the steps of: generating a self-resonant radio frequency power;
KR1020160028448A 2016-03-09 2016-03-09 Radio Frequency Power Generation Apparatus KR101812735B1 (en)

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WO2022093753A1 (en) * 2020-10-29 2022-05-05 Advanced Energy Industries, Inc. Systems and methods combining match networks and frequency tuning

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US4866592A (en) 1988-03-30 1989-09-12 Fuji Electric Co., Ltd. Control system for an inverter apparatus
EP0577105B1 (en) 1992-06-30 1997-12-10 Toshiba Lighting & Technology Corporation Inverter circuit and electrodeless discharge lamp lighting apparatus using the same
JP4108108B2 (en) * 2004-03-29 2008-06-25 三菱電機株式会社 Power supply for plasma generation

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022093753A1 (en) * 2020-10-29 2022-05-05 Advanced Energy Industries, Inc. Systems and methods combining match networks and frequency tuning

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