KR20220071153A - Power supply for high voltage generation - Google Patents

Abstract

The present invention relates to a power supply device for generating a high voltage capable of increasing reliability, durability, and economic feasibility by considering characteristics of a plasma load. To this end, the power supply device for generating a high voltage according to the present invention comprises: a half-bridge LLC converter for receiving a DC voltage and outputting an AC voltage boosted through a transforming unit; and an analog frequency detector for detecting a current and a voltage on a primary side of the transforming unit of the half-bridge LLC converter to output a signal for pulse width modulation (PWM) control to the half-bridge LLC converter.

Description

Power supply for high voltage generation

The present invention relates to a power supply for generating a high voltage that can improve reliability, durability, and economy in consideration of the characteristics of a plasma load.

Plasma refers to a state in which gas molecules are separated into atomic nuclei (cations) and electrons (ionized gas) at a high temperature.

A plasma discharge structure is usually composed of two electrodes and a dielectric. When an alternating voltage is applied between the two electrodes, a dielectric barrier discharge phenomenon, that is, a low-temperature plasma discharge, occurs between the dielectric and the electrode.

For plasma discharge, the power supply device must apply a controlled AC voltage to the plasma discharge structure, and the AC voltage output from the power supply device fluctuates due to internal factors of the power supply device or external factors according to plasma load fluctuations. Reliability and durability are problematic.

In addition, the conventional plasma power supply uses a digital circuit for voltage stabilization that requires individual programming and calibration, and includes high-speed machining parts for automatic tuning and synchronization, so the design is complicated and economical is poor.

Korean Patent No. 10-1706775

The present invention has been devised to solve the above problems, and an object of the present invention is to improve durability, reliability, and economy of a device for supplying power for plasma discharge.

To this end, the power supply device for generating a high voltage according to the present invention includes a half-bridge LLC converter that receives a DC voltage and outputs an AC voltage boosted through a transformer, and a primary side current and voltage of the transformer of the half-bridge LLC converter. and an analog frequency detector that detects and outputs a signal for PWM (Pulse Width Modulation) control to the half-bridge LLC converter.

A power supply device for generating a high voltage according to the present invention includes a converter that converts a DC voltage into a pulse to generate an AC voltage and outputs an AC voltage boosted through a transformer, and a transformer primary side current signal and voltage signal of the converter In this way, a signal for pulse width modulation (PWM) control is generated based on the zero crossing signal Zd according to the primary side current signal and the ramp signal Vr according to the zero crossing signal Zd and output to the converter. Includes a frequency detector.

As described above, in the power supply device for generating high voltage according to the present invention, since all circuits are composed of analog elements, the processing speed is high without unnecessary signal processing, the operation reliability is excellent, and the EMI/EMC requirements can be satisfied there is

The present invention has the effect of improving durability and reliability by detecting a decrease in output frequency and voltage according to a change in plasma load, correcting an error with the existing output, and supplying a constant frequency and voltage through stabilization.

Since the power supply device for generating high voltage according to the present invention does not require a separate data input for circuit operation and does not require a circuit for synchronization, the number of parts required due to the simplification of the design process is reduced, thereby improving economic efficiency. have.

1 is a view showing the internal configuration of a power supply for generating a high voltage according to the present invention.
2 is a diagram showing a circuit configuration of a switching unit according to the present invention.
3 is a view showing the circuit configuration of the resonance unit and the transformer according to the present invention.
4 is a diagram showing a circuit configuration of a zero-crossing detection unit according to the present invention.
5 is a diagram showing a circuit configuration of a lamp generating unit according to the present invention.
6 is a diagram illustrating signals of a zero-crossing detection unit and a ramp generating unit according to the present invention;
7 is a diagram illustrating a circuit configuration of a peak detection unit according to the present invention;
8 is a diagram showing the circuit configuration of the PI control unit according to the present invention.
9 is a diagram showing a circuit configuration of a PWM generator according to the present invention.
10 is a view showing input and output signals of a PWM generator according to the present invention.

Hereinafter, embodiments disclosed herein will be described in detail with reference to the accompanying drawings. In each drawing, like elements are assigned the same reference numerals, and overlapping descriptions thereof will be omitted.

The suffixes “…module”, “…part”, or “…member” for the components used in the following description are given or mixed in consideration of the ease of writing the specification, and have a meaning or role that is distinct from each other by itself. not to have

In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted.

In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical idea disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention, It should be understood to include equivalents and substitutes.

1 shows the configuration of a power supply device for generating a high voltage according to the present invention.

Referring to FIG. 1 , a power supply for generating a high voltage is largely composed of a half-bridge LLC converter 100 and an analog frequency detection with controller 200 .

The half-bridge LLC converter 100 receives a DC voltage and operates a series of circuits to output an AC voltage. In the embodiment of the present invention, the half-bridge LLC converter 100 converts DC 12V to AC 6kV and outputs it to a plasma generator (plasma discharge structure).

The analog frequency detector 200 detects the primary-side current and voltage of the transformer 103 of the half-bridge LLC converter 100 and controls PWM (Pulse Width Modulation) with the switching unit 101 of the half-bridge LLC converter 100 . output a signal for

The half-bridge LLC converter 100 includes a switching unit 101 , a resonance unit 102 , and a transformer 103 .

The switching unit 101 receives a DC voltage and outputs a pulse. A pulse width of the pulse output from the switching unit 101 is adjusted by a signal (gate triggering signal) for PWM control of the analog frequency detector 200 .

2 shows the circuit configuration of the switching unit 101 according to the present invention.

As shown in FIG. 2 , the switching unit 101 includes two MOSFET transistors 11 and 12 .

The gate driver 10 outputs signals for operating the two MOSFET transistors 11 and 12 . The gate driver 10 is a component included in the PWMM generator 205 of the analog frequency detector 200, and receives a quasi PWM signal and a zero crossing signal Vd as inputs (this will be described later), and triggers the gate A (gate triggering) signal is generated and output to the gates of the two MOSFETs (11, 12). A pulse signal is generated at an intermediate point between the two MOSFETs 11 and 12 and is input to the resonance unit 102 .

The resonator 102 converts the pulse output from the switching unit 101 into a sine wave (alternating current) and removes noise. The transformer 103 outputs the primary voltage output from the resonator 102 as a secondary voltage.

3 shows the circuit configuration of the resonator 102 and the transformer 103 according to the present invention.

As shown in FIG. 3 , the resonator 102 converts the pulse into a sine wave using the LC low-pass filter 20 and increases the voltage through the maximum voltage gain at the resonant frequency. The transformer 103 boosts the voltage of the resonator 102 through the turns ratio of the primary coil 21 and the secondary coil 22 and outputs the boosted voltage.

The analog frequency detector 200 receives the primary side voltage and current of the transformer 103 . The primary-side voltage signal of the transformer 103 is input to the peak detection unit 203 , and the primary-side current signal is input to the zero crossing detection unit 201 .

The analog frequency detector 200 includes a zero crossing detector 201 , a ramp generator 202 , a peak detector 203 , a Proprtional Integral (PI) controller 204 , and a PWM generator (205) and the like.

4 shows the circuit configuration of the zero-crossing detection unit 201 according to the present invention.

As shown in FIG. 4 , the zero-crossing detection unit 201 rectifies the current signal by half-wave using a diode 30 to output a half-wave rectified signal Vct, and a half-wave rectified signal Vct and A signal Zd is output by comparing the ground potential. The comparator 31 outputs a high signal in a positive cycle and a low signal in a negative cycle.

5 shows the circuit configuration of the lamp generating unit 202 according to the present invention.

As shown in FIG. 5 , when the ramp generating unit 202 receives a high signal from the zero crossing detecting unit 201 , a voltage is charged in the capacitor 41 through the resistor 40 . On the other hand, when the lamp generator 202 receives a low signal, the voltage stored in the capacitor 41 is rapidly discharged through the diode 42 . The voltage charged in the capacitor 41 becomes the ramp signal Vr and is input to the PWM generator 205 .

6 is a signal diagram illustrating a half-wave rectified signal Vct and a comparator output signal Zd of the zero-crossing detector 201 and a ramp signal Vr of the ramp generator 202 are compared with each other.

As shown in FIG. 6 , the half-wave rectified signal Vct is a half-wave rectified current signal of the transformer 103 primary side, and the comparator output signal Zd is generated by the comparator 31 with the half-wave rectified signal Vct. The ground potential is input and output, and the ramp signal Vr is a voltage charged in the capacitor 41 . Here, it can be seen that the ramp signal Vr is the same as the phase of the primary-side current signal of the transformer 103 .

7 shows the circuit configuration of the peak detection unit 203 .

As shown in FIG. 7 , the peak detection unit 203 receives a voltage signal, charges the rectified signal through the diode 50 in the capacitor 51 , and discharges the charged voltage through the high impedance resistor 52 . A signal is output by the smoothing action of the capacitor. That is, the peak detection unit 203 receives the primary-side voltage signal of the transformer 103 and outputs a peak value.

In an embodiment of the present invention, DC 12V is converted to AC 6kV and supplied to the plasma generator. DC 12V is boosted by the resonator 102 through the switching unit 101 and output to the primary side of the transformer 103, and the output AC voltage (pk-pk voltage) becomes 300V. Therefore, when the turns ratio of the primary coil and the secondary coil is 1:20, 6 kV can be output to the secondary side of the transformer 103 .

In order to stably supply a 6kV voltage to the plasma generator, the voltage applied to the primary coil side of the transformer 103 must be maintained at 300V. The voltage signal detected from the primary side of the transformer 103 is a voltage detected from the first winding of the primary coil. When the voltage applied to the primary coil side of the transformer 103 maintains 300V, the detected voltage signal becomes 3V, and the 3V voltage signal is output as 1.5V through the peak detector 203 . The signal (peak value) output from the peak detection unit 203 is input to the PI control unit 204 . According to the embodiment of the present invention, in order to stably supply 6kV, the reference voltage of the PI controller 204 should be 1.5V.

8 shows the circuit configuration of the PI control unit 204. As shown in FIG.

As shown in FIG. 8, the PI control unit 204 is composed of an RC circuit and a comparator, and compares the reference voltage (1.5V) with the input signal (input voltage) output from the peak detection unit 203 through the PI control to make an error. plays a role in removing In FIG. 8 , the reference voltage of the PI controller 204 is set to 1.5V for the above reason, but may be changed according to the voltage supplied to the plasma generator.

The PI control unit 204 compares the input voltage with the reference voltage and, when the input voltage is greater than the reference voltage, increases the output of the PI control unit 204 to decrease a certain amount of the circuit output, and when the input voltage is less than the reference voltage, the PI control unit ( 204) to increase the output of the circuit by a certain amount. The output signal Vpi of the PI control unit 204 is input to the PWM generation unit 205 .

9 shows the circuit configuration of the PWM generator 205. As shown in FIG.

As shown in FIG. 9 , the PWM generator 205 includes a comparator 60 , a gate driver 10 , and the like.

The comparator 60 compares the ramp signal Vr and the reference signal Vref by the PI output signal Vpi to output a quasi PWM signal Q-PWM. The gate driver 10 receives the comparator output signal Zd of the zero crossing detection unit 201 through an enable terminal, receives a pseudo PWM signal through the PWM terminal, and performs PWM control with the switching unit 101 . to output the gate triggering signal for

FIG. 10 is a signal diagram showing a reference signal Vref, a pseudo PWM signal Q-PWM, and a PWM signal PWM added to the signal diagram shown in FIG. 6 .

Here, the PWM signal PWM refers to a signal that the gate driver 10 receives the zero crossing signal Vd and the pseudo PWM signal Q-PWM and maintains therein.

The comparator output signal Zd of the zero crossing detection unit 201 acts as a rising edge of a gate triggering signal for PWM control, which is an output signal of the gate driver 10, and the pseudo PWM signal Q-PWM is It can be seen that it acts as a falling edge of the triggering signal.

The above detailed description should not be construed as restrictive in all respects and should be considered as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention.

100: half bridge LLC converter 101: switching unit
102: resonator 103: transformer
200: analog frequency detector 201: zero crossing detection unit
202: ramp generation unit 203: peak detection unit
204: PI control unit 205: PWM generation unit

Claims (1)

A half-bridge LLC converter that receives a DC voltage and outputs an AC voltage boosted through a transformer;
Detects the primary side current and voltage of the transformer of the half-bridge LLC converter, and receives a high or low signal output according to the primary side current and a signal generated according to the voltage charged and discharged by the high or low signal , A power supply for generating a high voltage including an analog frequency detector for outputting a signal for PWM (Pulse Width Modulation) control to the half-bridge LLC converter.

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