A sputtering coating power supply control system that reduces protection trigger frequency

Abstract

This application discloses a sputtering coating power supply control system for reducing protection trigger frequency, belonging to the field of DC sputtering coating. It includes a signal acquisition subsystem, a start-up control subsystem, a steady-state control subsystem, and a transient control subsystem. The signal acquisition subsystem provides the voltage and current signals required for power calculation. The start-up control subsystem controls the voltage boost and deceleration inputs according to the load characteristics. When the load exhibits corona discharge characteristics, rapid voltage boost is achieved through input control via the voltage integral control module. When the load characteristics enter the glow discharge region, deceleration input is achieved through input signals via the current integral control module, and the voltage at this time is recorded as the voltage basis for constant power output to calculate the target current. The steady-state control subsystem maintains the stability of the output voltage, ensuring the system is in a stable state. When the load enters the arc discharge region, transient phase-shift control reduces the current, minimizes protection actions, and quickly restores the system to normal operating status.

Description

Technical Field

[0001] This application belongs to the field of DC sputtering coating, and particularly relates to a sputtering coating power supply control system that reduces the protection trigger frequency. Background Technology

[0002] Currently, the most mature DC power supplies are those that adopt the LLC topology. Figure 1 This is a common DC power supply circuit topology, typically consisting of an AC-DC converter with a front-end AC-DC converter and a back-end isolated DC-DC converter. The front-end circuit converts the mains AC voltage into a constant DC voltage, and usually ensures that the input AC current and AC voltage are in phase. The isolated DC-DC converter uses an LLC resonant cavity to convert the constant voltage output from the front-end into the voltage required by the back-end, thus meeting the coating requirements in various scenarios.

[0003] Common LLC power supply voltage regulation control methods include PFM control (frequency converter control) and PSM control (phase shift control). Both methods can achieve ZVS for the power switching transistors and meet the requirements for converter output voltage gain adjustment. Since frequency converter control operates at a frequency higher than the resonant frequency, the secondary diode of the LLC will be in a hard-switching state. Therefore, unless there are special requirements, frequency converter control usually only uses the resonant frequency or a lower frequency, at which point the voltage gain is 1 or greater. Phase shift control reduces the output by decreasing the primary-side duty cycle, resulting in a voltage gain less than 1. Therefore, for a wide gain range, they are usually used in combination, with a voltage regulation range as follows: Figure 1 As shown.

[0004] Although LLC power supplies have been developed in China for many years, there is little research on the development of power supplies specifically for coating. LLC power supplies use PI control, which, while applicable, does not address the changing load characteristics during the coating process, thus significantly impacting coating accuracy and uniformity. Finding domestic power supply alternatives is a pressing issue for the sputtering coating industry. Considering the background technology of coating power supplies and existing power supply structures, developing a control system suitable for coating power supplies is the most economically effective approach. Summary of the Invention

[0005] The present invention provides a sputtering coating power supply control system that reduces the protection trigger frequency, so as to at least solve or alleviate one or more technical problems in the prior art, or at least provide a beneficial alternative.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A sputtering coating power supply control system for reducing protection trigger frequency includes a signal acquisition subsystem, a startup control subsystem, a steady-state control subsystem, and a transient control subsystem. The input terminal of the signal acquisition subsystem is electrically connected to the DC output terminal, and the output terminal is electrically connected to the startup control subsystem, the steady-state control subsystem, and the transient control subsystem, respectively.

[0008] The signal acquisition subsystem includes a voltage signal acquisition module and a current signal acquisition module, which provide the voltage and current required for power calculation and the signal data required for control mode switching.

[0009] The startup control subsystem includes a switching integrator, a voltage integral control module, and a current integral control module. When the power supply is started, the load exhibits corona discharge characteristics. The switching integrator uses the input signal from the voltage integral control module to control the rapid voltage boost. When the load characteristics enter the glow discharge region, the switching integrator uses the input signal from the current proportional module to control the deceleration input and records the voltage at this time as the basis for constant power output to calculate the target current.

[0010] The steady-state control subsystem includes a current hysteresis control module, a control switching module, a sliding mode control module, and a timing latch module. The current hysteresis control module maintains the output power within a specified range. The control switching module switches the input of the sliding mode control module and switches the integrator to record the output integral value. The timing latch module calculates the corresponding PWM cycle based on the input and maintains the output for one cycle, thereby ensuring the stability of the output voltage.

[0011] The transient control subsystem and the sliding mode control module start simultaneously. When the load enters arc discharge, the transient phase-shift control value is output based on the sampled current rise value to perform transient phase shifting, reduce the current, and the control switching module switches to the switching integrator input. The switching integrator outputs the stored integral value and quickly switches back to the sliding mode control module input to restore normal operation, thereby reducing protection actions.

[0012] The sputtering coating power supply with reduced protection trigger frequency of this application combines multiple control modules based on the traditional power supply topology and the load characteristics of sputtering coating, and specializes the coating function to improve its stability and uniformity during coating. The signal acquisition system provides the voltage and current signals required for power calculation, and also supports the signal data required for control mode switching. The start-up control subsystem controls the voltage boost and deceleration input based on the load characteristics. When the load exhibits corona discharge characteristics, the voltage integral control module controls the input to achieve rapid voltage boost. When the load characteristics enter the glow discharge region, the current integral control module controls the input signal to achieve deceleration input and records the voltage at this time as the basis for constant power output voltage. The target current is calculated, and the steady-state control subsystem maintains the stability of the output voltage to ensure the system is in a stable state. When the load enters arc discharge, transient phase shift control reduces the current, reduces protection actions, and quickly restores the system to normal operating state. When the load enters different discharge states, the system can intelligently adjust the control strategy to ensure the stability and accuracy of the power output, while reducing protection actions, improving the system's reliability and efficiency, and helping to reduce the frequency of protection triggering, thereby improving the quality and efficiency of coating.

[0013] In a preferred implementation, the input terminal of the voltage integral control module is electrically connected to the voltage signal acquisition module, and the output terminal is electrically connected to the first terminal of the switching integrator. The input terminal of the current integral control module is electrically connected to the current signal acquisition module, and the output terminal is electrically connected to the second terminal of the switching integrator. The switching integrator is electrically connected to the steady-state control subsystem.

[0014] In a preferred implementation, the first terminal of the control switching module is electrically connected to the shared output terminal of the switching integrator, the second terminal of the control switching module is electrically connected to the output terminal of the sliding mode control module, the third terminal of the control switching module is electrically connected to the first terminal of the timing latch module, the input terminal of the sliding mode control module is electrically connected to the second terminal of the timing latch module, and the second terminal of the timing latch module is electrically connected to the transient control subsystem.

[0015] In a preferred implementation, the transient control subsystem includes a current register module, a transient phase-shifting module, and a switch drive module. The input terminal of the current register module is electrically connected to the output terminal of the current signal acquisition module, the output terminal of the current register module is electrically connected to the input terminal of the transient phase-shifting module, the output terminal of the transient phase-shifting module is electrically connected to the first terminal of the switch drive module, the second terminal of the switch drive module is electrically connected to the second terminal of the timing latch module, and the third terminal of the switch drive module is electrically connected to the main circuit inverter module.

[0016] In a preferred implementation, when the input from the timing latch module rises from zero, the frequency of the output PWM wave of the switch drive module is the resonant frequency, and the phase shift angle gradually decreases. When the phase shift angle is zero, the switch drive module enters the frequency modulation mode, the phase shift angle is zero, and the frequency gradually decreases.

[0017] In a preferred implementation, when the switch driving module receives input from the transient phase shifting module, it determines whether the transient phase shifting control value exceeds a threshold. If the threshold is exceeded, the switch driving module performs phase shifting based on the transient phase shifting control value.

[0018] In the preferred implementation, the total phase shift angle is ≤180°.

[0019] Controlling the phase shift angle within the range of ≤180° can optimize power transmission efficiency in the system. Appropriate phase shift angle settings ensure effective matching between the power supply and the load, reduce power loss, and improve the overall system's energy conversion efficiency.

[0020] In a preferred implementation, the control switching module lowers its trigger current threshold after the first trigger to prevent oscillation from causing instability.

[0021] In the preferred implementation, the current rise value is the difference between the current value and the current value three cycles ago, and multiple samples are taken within a single cycle. The sum of the multiple sampled differences is used as the transient phase shift control value to reduce the interference of ripple on the determination. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and, together with their description, serve to explain this application and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 This is a common power supply main circuit topology diagram;

[0024] Figure 2 This is a schematic diagram of the control system process;

[0025] Figure 3 This is a schematic diagram of the load current-voltage curve;

[0026] Figure 4 This is a schematic diagram of the control system topology;

[0027] Figure 1-4 In Chinese, the symbol is represented as:

[0028] 1-AC-DC module, 2-DC-DC module, 3-Inverter module, 4-LLC resonant cavity, 5-Current signal acquisition module, 6-Voltage signal acquisition module, 7-Current integral control module, 8-Voltage integral control module, 9-Switching integrator, 10-Control switching module, 11-Sliding mode control module, 12-Timing latch module, 13-Current register module, 14-Transient phase shifting module, 15-Switch drive module, 16-Signal acquisition subsystem, 17-Startup control subsystem, 18-Steady-state control subsystem, 19-Transient control subsystem. Detailed Implementation

[0029] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit and scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0030] First, the technical concept of the technical solution disclosed in this invention will be explained.

[0031] See Figure 1 This is a common DC power supply circuit topology, consisting of a front-end AC-DC module 1 and a back-end isolated DC-DC module 2, forming an AC-DC converter. The front-end circuit converts the mains AC voltage into a constant DC voltage, and typically ensures that the input AC current and AC voltage are in phase. The isolated DC-DC converter includes an inverter module 3 and an LLC resonant cavity 4, which converts the constant voltage output from the front end into the voltage required by the back end, meeting the coating needs of various scenarios.

[0032] Common LLC power supplies use PI control, which is applicable, but because PI control cannot accurately match the changes in load characteristics during the coating process, it will trigger protection actions, causing fluctuations in coating thickness and thus affecting the coating accuracy. For example, in some areas, the coating may be too thick or too thin, failing to meet the product's performance requirements. Considering the above-mentioned problems, this invention provides a sputtering coating power supply control system that reduces the protection trigger frequency.

[0033] The present invention will now be described with reference to the accompanying drawings.

[0034] See Figure 2-4A sputtering coating power supply control system for reducing protection trigger frequency includes: a signal acquisition subsystem 16, a start-up control subsystem 17, a steady-state control subsystem 18, and a transient control subsystem 19. The input terminal of the signal acquisition subsystem 16 is the load-side voltage and current, and the output terminal of the signal acquisition subsystem 16 is electrically connected to the start-up control subsystem 17, the steady-state control subsystem 18, and the transient control subsystem 19, respectively. The control system switches the operation of the subsystems according to the changes in load characteristics to realize the switching of control strategies. Under normal operating conditions, the steady-state control subsystem and the transient control subsystem operate simultaneously.

[0035] The signal acquisition subsystem 16 includes a voltage signal acquisition module 6 and a current signal acquisition module 6. The input terminal of the signal acquisition subsystem is electrically connected to the DC output terminal. The output terminal of the voltage signal acquisition module 6 is electrically connected to the input terminal of the start-up control subsystem 17. The output terminal of the current signal acquisition module 6 is electrically connected to the input terminals of the start-up control subsystem 17, the steady-state control subsystem 18, and the transient control subsystem 18.

[0036] The signal acquisition subsystem 16 is designed to provide the voltage and current required for power calculation and to provide the signal data support required for control mode switching.

[0037] The start-up control subsystem 17 includes a voltage integral control module 8, a current integral control module 7, and a switching integrator 9. The input terminal of the voltage integral control module 8 is electrically connected to the voltage signal acquisition module 6, and the output terminal is electrically connected to the first terminal of the switching integrator 9. The input terminal of the current integral control module 7 is electrically connected to the current signal acquisition module 5, and the output terminal is electrically connected to the second terminal of the switching integrator 9. The switching integrator 9 is electrically connected to the steady-state control subsystem.

[0038] The steady-state control subsystem 18 includes a control switching module 10, a sliding mode control module 11, and a timing latch module 12. The first terminal of the control switching module is electrically connected to the shared output terminal of the switching integrator. The second terminal of the control switching module 10 is electrically connected to the output terminal of the sliding mode control module 11. The third terminal of the control switching module 10 is electrically connected to the first terminal of the timing latch module 12. The input terminal of the sliding mode control module 11 is electrically connected to the second terminal of the timing latch module 12. The second terminal of the timing latch module 12 is electrically connected to the transient control subsystem.

[0039] The transient control subsystem 19 includes a current register module 13, a transient phase shift module 14, and a switch drive module 15. The input terminal of the current register module 13 is electrically connected to the output terminal of the current signal acquisition module 5. The output terminal of the current register module 13 is electrically connected to the input terminal of the transient phase shift module 14. The output terminal of the transient phase shift module 14 is electrically connected to the first terminal of the switch drive module 15. The second terminal of the switch drive module 15 is electrically connected to the second terminal of the timing latch module 12. The third terminal of the switch drive module 15 is electrically connected to the main circuit inverter module.

[0040] When the power supply starts, the switching integrator 9 starts counting from zero. At this time, the power supply output current and voltage also rise from zero. The load exhibits corona discharge characteristics, and the current changes slowly with the voltage. The switching integrator 9 uses the input signal of the voltage integration control module 8 to control the rapid voltage increase. When the load characteristics enter the glow discharge region, the current rises rapidly with the voltage, and the voltage change is not obvious. It can be considered that the load has voltage regulation characteristics at this time and needs to reduce the input speed. At this time, the switching integrator 9 uses the input signal of the current integration control module 7 to control the speed reduction and records the voltage at this time as the basis for constant power output voltage to calculate the target current.

[0041] When the measured current approaches the target current, the current hysteresis control module maintains the output power within the range of the specified power. The control switching module 10 changes the input of the switching integrator 9 to the input of the sliding mode control module 11, and at this time, the switching integrator 9 records the output integral value.

[0042] Meanwhile, the control switching module 10 lowers its trigger current threshold after the first trigger to prevent oscillation from causing instability.

[0043] During the input period of the sliding mode control module 11, it can be regarded as the normal working state. At this time, the current rise rate is relatively linear, and it is easy to eliminate its interference. The timing latch module 12 calculates the PWM period corresponding to the input value and keeps the output value for one cycle, thereby ensuring the stability of the output voltage. After one cycle, the timing latch module 12 accepts the current input value and keeps the output for one cycle corresponding to the input value.

[0044] Simultaneously, when the input of integrator 9 is switched to the input of sliding mode control module 11, transient control module 14 is activated. It outputs a transient phase-shift control value based on the sampled current rise, reducing the output voltage. It's important to note that the transient phase-shift control value also operates on a PWM wave cycle basis. The current rise is approximately the difference between the current value and the current value three cycles ago. Multiple samples are taken within a single cycle, and the sum of these differences is used as the transient phase-shift control value to reduce ripple interference in the decision-making process. It should be noted that the transient phase-shift control values ​​are not independent of each other during the cycle; the generated transient phase-shift control value decays exponentially to prevent excessively rapid recovery from causing another fault.

[0045] When the input from the timing latch module 12 to the switch drive module 15 rises from zero, its output PWM wave frequency is the resonant frequency, and the phase shift angle gradually decreases from 180°. When the phase shift angle is zero, the switch drive module 15 enters the frequency modulation mode, the phase shift angle is zero, and the frequency gradually decreases.

[0046] When the switch drive module 15 receives the input from the transient phase shift module 14, it first determines whether the transient phase shift control value exceeds a certain value. Otherwise, it does not operate. When it exceeds the certain value, the switch drive module 15 performs phase shifting according to the value. It should be noted that the total phase shift angle cannot exceed 180°. The transient phase shift has a relatively small impact on non-arc discharge conditions. Under normal operating conditions, the current adjustment should be small, so it does not affect the normal operating conditions.

[0047] When an arc discharge fault occurs on the load side, the current rises sharply. The current register module 13 transmits information to the transient phase-shifting module 14, causing the transient phase-shifting module 14 to output a larger value. The switch drive module 15 then performs phase shifting to reduce power output and lower the current, thereby resolving the fault. If the current reduction is too large, the control switching module 10 switches back to the input of the switching integrator 9. The switching integrator 9 outputs the latched integral value. Simultaneously, due to the lowered trigger current threshold, the control switching module 10 quickly switches back to the input of the sliding mode control module 11, restoring normal operation and thus reducing protection actions.

[0048] For any parts not mentioned in this invention, existing technologies can be used or referenced.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A sputtering coating power supply control system for reducing protection trigger frequency, characterized in that, It includes a signal acquisition subsystem, a startup control subsystem, a steady-state control subsystem, and a transient control subsystem. The input terminal of the signal acquisition subsystem is electrically connected to the DC output terminal, and the output terminal is electrically connected to the startup control subsystem, the steady-state control subsystem, and the transient control subsystem, respectively. The signal acquisition subsystem includes a voltage signal acquisition module and a current signal acquisition module, which provide the voltage and current required for power calculation and the signal data required for control mode switching. The startup control subsystem includes a switching integrator, a voltage integral control module, and a current integral control module. When the power supply is started, the load exhibits corona discharge characteristics. The switching integrator uses the input signal from the voltage integral control module to control the rapid voltage boost. When the load characteristics enter the glow discharge region, the switching integrator uses the input signal from the current proportional module to control the deceleration input and records the voltage at this time as the basis for constant power output to calculate the target current. The steady-state control subsystem includes a current hysteresis control module, a control switching module, a sliding mode control module, and a timing latch module. The current hysteresis control module maintains the output power within a specified range. The control switching module switches the input of the sliding mode control module and switches the integrator to record the output integral value. The timing latch module calculates the corresponding PWM cycle based on the input and maintains the output for one cycle, thereby ensuring the stability of the output voltage. The transient control subsystem and the sliding mode control module start simultaneously. When the load enters arc discharge, the transient phase-shift control value is output based on the sampled current rise value to perform transient phase shifting, reduce the current, and the control switching module switches to the switching integrator input. The switching integrator outputs the stored integral value and quickly switches back to the sliding mode control module input to restore normal operation, thereby reducing protection actions.

2. The sputtering coating power supply control system for reducing protection trigger frequency according to claim 1, characterized in that, The input terminal of the voltage integral control module is electrically connected to the voltage signal acquisition module, and the output terminal is electrically connected to the first terminal of the switching integrator. The input terminal of the current integral control module is electrically connected to the current signal acquisition module, and the output terminal is electrically connected to the second terminal of the switching integrator. The switching integrator is electrically connected to the steady-state control subsystem.

3. The sputtering coating power supply control system for reducing protection trigger frequency according to claim 2, characterized in that, The first terminal of the control switching module is electrically connected to the shared output terminal of the switching integrator. The second terminal of the control switching module is electrically connected to the output terminal of the sliding mode control module. The third terminal of the control switching module is electrically connected to the first terminal of the timing latch module. The input terminal of the sliding mode control module is electrically connected to the second terminal of the timing latch module. The second terminal of the timing latch module is electrically connected to the transient control subsystem.

4. The sputtering coating power supply control system for reducing protection trigger frequency according to claim 3, characterized in that, The transient control subsystem includes a current register module, a transient phase shift module, and a switch drive module. The input terminal of the current register module is electrically connected to the output terminal of the current signal acquisition module, the output terminal of the current register module is electrically connected to the input terminal of the transient phase shift module, the output terminal of the transient phase shift module is electrically connected to the first terminal of the switch drive module, the second terminal of the switch drive module is electrically connected to the second terminal of the timing latch module, and the third terminal of the switch drive module is electrically connected to the main circuit inverter module.

5. The sputtering coating power supply control system for reducing protection trigger frequency according to claim 4, characterized in that, When the input from the timing latch module rises from zero, the frequency of the output PWM wave of the switch drive module is the resonant frequency, and the phase shift angle gradually decreases. When the phase shift angle is zero, the switch drive module enters the frequency modulation mode, the phase shift angle is zero, and the frequency gradually decreases.

6. The sputtering coating power supply control system for reducing protection trigger frequency according to claim 5, characterized in that, When the switch drive module receives the input from the transient phase shift module, it determines whether the transient phase shift control value exceeds the threshold. If it exceeds the threshold, the switch drive module performs phase shifting according to the transient phase shift control value.

7. The sputtering coating power supply control system for reducing protection trigger frequency according to claim 6, characterized in that, Total phase shift angle ≤ 180°.

8. The sputtering coating power supply control system for reducing protection trigger frequency according to claim 1, characterized in that, The control switching module lowers its trigger current threshold after the first trigger to prevent oscillation from causing instability.

9. The sputtering coating power supply control system for reducing protection trigger frequency according to claim 1, characterized in that, The current rise value is the difference between the current value and the current value three cycles ago, and multiple samples are taken within a single cycle. The sum of multiple sampled differences is used as the transient phase shift control value to reduce the interference of ripple on the judgment.

Images