Pulse direct-current coating power supply, abnormal discharge protection method, system and equipment

Abstract

The invention discloses a pulse direct-current coating power supply, and an abnormal discharge protection method, system and device. The power supply comprises an alternating-current input end, a rectification filter circuit, a full-bridge converter circuit, a single-phase bridge type rectification circuit, a switching tube S5, a load output end and a controller. The full-bridge converter circuit comprises a first group of switching tubes and a second group of switching tubes, and the controller controls the first group of switching tubes and the second group of switching tubes to be switched on in turn in a period; and the controller controls the switch tube S5 to be switched on within a dead zone time between turn-on of the first group of switch tubes and turn-on of the second group of switch tubes. The performance of the pulse direct-current coating power supply in the aspects of pulse shape, pulse repetition rate, service life, stability and the like can be improved, and the requirements for improving the quality and performance of a film layer are met.

Description

Technical Field

[0001] The present application relates to the field of film coating, and in particular to a pulsed DC film coating power supply, an abnormal discharge protection method, system and equipment. Background Art

[0002] Pulsed DC coating power supplies are widely used in reactive sputtering coating technology. They provide a periodic negative voltage followed by a short duration of zero voltage (or positive pulse), with a typical repetition frequency between 20 and 300kHz.

[0003] In the related technology, the pulsed DC coating power supply has the problems of complex structure, high cost and difficulty in high power. Therefore, the performance of the pulsed DC coating power supply in terms of pulse shape, pulse repetition rate, life and stability is insufficient and cannot meet the requirements of improving the quality and performance of the film layer. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a pulsed DC coating power supply, an abnormal discharge protection method, a system and a device, which can improve the performance of the pulsed DC coating power supply in terms of pulse shape, pulse repetition rate, life and stability, and meet the needs of improving the quality and performance of the film layer.

[0005] The pulsed DC coating power supply according to the first embodiment of the present application includes:

[0006] AC input terminal, used for inputting AC power;

[0007] A rectifier and filter circuit, wherein the AC input terminal is connected to an input terminal of the rectifier and filter circuit;

[0008] A full-bridge converter circuit, the full-bridge converter circuit comprises a switch tube S1, a switch tube S2, a switch tube S3, a switch tube S4 and a transformer TR1, the positive electrode of the output end of the rectifier and filter circuit is respectively connected to the drain of the switch tube S1 and the switch tube S3, the source of the switch tube S1 is connected to the drain of the switch tube S2, the source of the switch tube S3 is connected to the drain of the switch tube S4, the negative electrode of the output end of the rectifier and filter circuit is respectively connected to the source of the switch tube S2 and the source of the switch tube S4, the common end of the switch tube S1 and the switch tube S2 is connected to one end of the primary winding of the transformer TR1, and the common end of the switch tube S3 and the switch tube S4 is connected to the other end of the primary winding of the transformer TR1;

[0009] A single-phase bridge rectifier circuit, wherein the secondary winding of the transformer TR1 is connected to the input end of the single-phase bridge rectifier circuit;

[0010] The switch tube S5, the positive electrode of the output end of the single-phase bridge rectifier circuit is connected to the drain of the switch tube S5, and the negative electrode of the output end of the single-phase bridge rectifier circuit is connected to the source of the switch tube S5 through the inductor L2;

[0011] A load output end, the drain and source of the switch tube S5 are respectively connected to two ends of the load output end, and the load output end is used to connect a coating load;

[0012] A controller, wherein the signal output end of the controller is respectively connected to the gates of the switch tube S1, the switch tube S2, the switch tube S3, the switch tube S4 and the switch tube S5, the switch tube S1 and the switch tube S4 are a first group of switch tubes with the same phase, the switch tube S2 and the switch tube S3 are a second group of switch tubes with the same phase, the first group of switch tubes and the second group of switch tubes have opposite phases, within one cycle, the controller controls the first group of switch tubes and the second group of switch tubes to be turned on in turn, and the controller controls the switch tube S5 to be turned on within the dead time between the first group of switch tubes and the second group of switch tubes being turned on in turn.

[0013] The pulsed DC coating power supply according to the first aspect of the present application has at least the following beneficial effects:

[0014] In the implementation mode of the present application, the rectifier and filter circuit performs rectification and filtering processing to convert the AC power supply into a DC voltage, and then the full-bridge converter circuit converts the DC voltage into a high-frequency AC voltage signal and outputs it to the load output terminal to provide power output for the coating load. In one cycle, the controller controls the first group of switch tubes and the second group of switch tubes to be turned on in turn, and the controller controls the switch tube S5 to be turned on during the dead time between the first group of switch tubes and the second group of switch tubes being turned on in turn.

[0015] This application cleverly realizes the output of pulse current and voltage by controlling the timing of the switch tubes S1-S5. The output frequency can be up to twice the switching frequency of the full-bridge converter, so the generated pulse frequency range is wider, which can make the load plasma discharge more uniform. At the same time, the dead time between the first group of switch tubes and the second group of switch tubes is used to realize pulse output, which greatly reduces the current capacity and voltage stress of the switch tube S5 and improves safety. This application utilizes the current continuity of the inductor L2 and the fast switching function of the semiconductor switch tube to achieve a rapid rise in the output current, ensure the high consistency of each pulse coating energy, and further ensure the uniformity of the coating.

[0016] In summary, the present application can improve the performance of the pulsed DC coating power supply in terms of pulse shape, pulse repetition rate, life and stability, and meet the needs of improving the quality and performance of the film layer.

[0017] According to some embodiments of the present application, a diode D1 is further included, the drain of the switch tube S5 is connected to the cathode of the diode D1, and the anode of the diode D1 is connected to the negative electrode of the load output terminal.

[0018] According to some embodiments of the present application, a diode D2 is further included, wherein a cathode of the diode D2 is connected to a positive electrode of the load output terminal, and an anode of the diode D2 is connected to a negative electrode of the load output terminal.

[0019] According to some embodiments of the present application, it also includes a capacitor C3, a diode D3, a switch tube S6, a diode D4 and a resistor R1, the cathode of the capacitor C3 is connected to the drain of the switch tube S5, the positive electrode of the capacitor C3 is respectively connected to the cathode of the diode D3 and the drain of the switch tube S6, the anode of the diode D3 is connected to the positive electrode of the load output end, the source of the switch tube S6 is connected to the anode of the diode D4, the cathode of the diode D4 is connected to the positive electrode of the load output end through the resistor R1, and the controller is connected to the gate of the switch tube S6 to control the conduction time of the switch tube S6 within the dead time to adjust the leading edge peak voltage of the load output end.

[0020] According to some embodiments of the present application, the controller controls the on and off of the switch tubes S1 , S2 , S3 , S4 , S5 and S6 through a pulse width modulation control signal.

[0021] According to some embodiments of the present application, the controller controls the on and off of the switch tubes S1 , S2 , S3 , S4 , S5 and S6 through a phase-shift control signal.

[0022] According to the abnormal discharge protection method of the second embodiment of the present application, the following steps are included:

[0023] Acquiring coating state information, wherein the coating state information is used to indicate a working state during the coating process;

[0024] When the coating state information indicates that an abnormal discharge state exists during the coating process, the switch tubes S1 , S2 , S3 and S4 are controlled to be turned off, and the switch tube S5 is controlled to be turned on.

[0025] The abnormal discharge protection method according to the second aspect of the present application has at least the following beneficial effects:

[0026] In the implementation manner of the present application, the coating state information is first obtained; then, when the coating state information indicates that an abnormal discharge state exists during the coating process, the switch tubes S1, S2, S3, and S4 are controlled to be turned off, and the switch tube S5 is controlled to be turned on. Rapid protection against abnormal discharge during the coating process can be achieved, further improving safety.

[0027] According to the pulsed DC coating system of the third aspect of the present application, the pulsed DC coating system comprises a coating device and the pulsed DC coating power supply, wherein the coating device is connected to the pulsed DC coating power supply.

[0028] The pulsed DC coating system according to the third aspect of the present application has at least the following beneficial effects:

[0029] In the implementation mode of the present application, the rectifier and filter circuit performs rectification and filtering processing to convert the AC power supply into a DC voltage, and then the full-bridge converter circuit converts the DC voltage into a high-frequency AC voltage signal and outputs it to the load output terminal to provide power output for the coating load. In one cycle, the controller controls the first group of switch tubes and the second group of switch tubes to be turned on in turn, and the controller controls the switch tube S5 to be turned on during the dead time between the first group of switch tubes and the second group of switch tubes being turned on in turn.

[0030] This application cleverly realizes the output of pulse current and voltage by controlling the timing of the switch tubes S1-S5. The output frequency can be up to twice the switching frequency of the full-bridge converter, so the generated pulse frequency range is wider, which can make the load plasma discharge more uniform. At the same time, the dead time between the first group of switch tubes and the second group of switch tubes is used to realize pulse output, which greatly reduces the current capacity and voltage stress of the switch tube S5 and improves safety. This application utilizes the current continuity of the inductor L2 and the fast switching function of the semiconductor switch tube to achieve a rapid rise in the output current, ensure the high consistency of each pulse coating energy, and further ensure the uniformity of the coating.

[0031] In summary, the present application can improve the performance of the pulsed DC coating power supply in terms of pulse shape, pulse repetition rate, life and stability, and meet the needs of improving the quality and performance of the film layer.

[0032] An electronic device according to an embodiment of the fourth aspect of the present application includes the above-mentioned pulsed DC coating power supply.

[0033] The electronic device according to the fourth aspect of the present application has at least the following beneficial effects:

[0034] In the implementation mode of the present application, the rectifier and filter circuit performs rectification and filtering processing to convert the AC power supply into a DC voltage, and then the full-bridge converter circuit converts the DC voltage into a high-frequency AC voltage signal and outputs it to the load output terminal to provide power output for the coating load. In one cycle, the controller controls the first group of switch tubes and the second group of switch tubes to be turned on in turn, and the controller controls the switch tube S5 to be turned on during the dead time between the first group of switch tubes and the second group of switch tubes being turned on in turn.

[0035] This application cleverly realizes the output of pulse current and voltage by controlling the timing of the switch tubes S1-S5. The output frequency can be up to twice the switching frequency of the full-bridge converter, so the generated pulse frequency range is wider, which can make the load plasma discharge more uniform. At the same time, the dead time between the first group of switch tubes and the second group of switch tubes is used to realize pulse output, which greatly reduces the current capacity and voltage stress of the switch tube S5 and improves safety. This application utilizes the current continuity of the inductor L2 and the fast switching function of the semiconductor switch tube to achieve a rapid rise in the output current, ensure the high consistency of each pulse coating energy, and further ensure the uniformity of the coating.

[0036] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present application is further described below with reference to the accompanying drawings and embodiments, wherein:

[0038] Figure 1 This is a circuit schematic diagram of a pulsed DC coating power supply in an embodiment of the present application;

[0039] Figure 2 This is a basic control timing and output waveform diagram in the embodiment of the present application;

[0040] Figure 3 This is a diagram of the same frequency working control timing and output waveform in the embodiment of the present application;

[0041] Figure 4 This is a circuit schematic diagram of another pulsed DC coating power supply in an embodiment of the present application;

[0042] Figure 5 Flow chart of the abnormal discharge protection method in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0044] In the description of the present application, it should be understood that the descriptions involving orientation, such as the orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0045] In the description of this application, "a plurality" means more than two. If there is a description of "first" or "second", it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0046] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0047] Reference Figure 1 As shown, a pulsed DC coating power supply includes: an AC input terminal, a rectifier filter circuit, a full-bridge converter circuit, a single-phase bridge rectifier circuit, a switch tube S5, a load output terminal and a controller. Specifically, the AC input terminal is used to input an AC power supply. In the embodiment of the present application, the AC input terminal is connected to the three-phase mains VS.

[0048] The AC input terminal is connected to the input terminal of the rectifier filter circuit. Specifically, in this embodiment, the rectifier filter circuit includes a three-phase rectifier circuit composed of diodes BD1-BD6, and a DC filter circuit composed of inductor L1 and capacitor C1, wherein in this embodiment, diodes BD1-BD6 are all power frequency rectifier diodes, and inductor L1 is a low-frequency filter inductor. The upper end of the three-phase rectifier circuit is connected to the left end of the inductor L1, the right end of the inductor L1 is connected to the positive electrode of the capacitor C1, and the lower end of the three-phase rectifier circuit is a low potential end, which is connected to the negative electrode of the capacitor C1.

[0049] The function of the full-bridge converter circuit is to convert the DC voltage output by the previous rectifier and filter circuit into a high-frequency AC voltage signal and to complete the electrical isolation from the power grid. The full-bridge converter circuit includes switch tube S1, switch tube S2, switch tube S3, switch tube S4 and transformer TR1. Switch tube S1 and switch tube S2 are the left bridge arm, and switch tube S3 and switch tube S4 are the right bridge arm. The positive electrode of the output end of the rectifier and filter circuit, that is, the cathode of the diodes BD1, BD3 and BD5, is connected to the switch tube S1 and the switch tube through the inductor L1. The drain of the switch tube S3, the source of the switch tube S1 is connected to the drain of the switch tube S2, the source of the switch tube S3 is connected to the drain of the switch tube S4, the negative electrode of the output end of the rectifier and filter circuit, that is, the anodes of the diodes BD2, BD4 and BD6 are respectively connected to the sources of the switch tubes S2 and S4, the common end of the switch tubes S1 and S2, that is, the left arm midpoint C is connected to one end of the primary winding of the transformer TR1; the common end of the switch tubes S3 and S4, that is, the right arm midpoint D is connected to the other end of the primary winding of the transformer TR1.

[0050] The single-phase bridge rectifier circuit is composed of diodes BD7-BD10. In this embodiment, diodes BD7-BD10 are all high-frequency rectifier diodes. The secondary winding of transformer TR1 is connected to the input end of the single-phase bridge rectifier circuit; the positive electrode of the output end of the single-phase bridge rectifier circuit is connected to the drain of the switch tube S5, and the negative electrode of the output end of the single-phase bridge rectifier circuit is connected to the source of the switch tube S5 through the inductor L2; the drain and source of the switch tube S5 are respectively connected to the two ends of the load output end. Specifically, in this embodiment, the drain of the switch tube S5 is connected to point A, and the source is connected to point B. Point A is the positive electrode of the load output end, connected to the anode shell ground of the coating equipment load, and point B is the negative electrode of the load output end. The load output end is used to connect the coating load, and the pulse DC power supply is output from points A and B. The resistor RL is the load equivalent resistance; the inductor L3 is the parasitic equivalent inductance of the connecting line between the power supply and the load; the inductor L2 is a high-frequency inductor, which is composed of a ferrite high-frequency magnetic core and copper wire, and the transformer TR1 is a high-frequency isolation transformer.

[0051] The signal output end of the controller is connected to the gates of the switch tubes S1, S2, S3, S4 and S5 respectively. The switch tubes S1 and S4 are the first group of switch tubes with the same phase, the switch tubes S2 and S3 are the second group of switch tubes with the same phase, and the phases of the first group of switch tubes and the second group of switch tubes are opposite. In one cycle, the controller controls the first group of switch tubes and the second group of switch tubes to be turned on alternately, and the controller controls the switch tube S5 to be turned on during the dead time between the first group of switch tubes and the second group of switch tubes being turned on alternately.

[0052] Among them, in this embodiment, the switch tube S1, the switch tube S2, the switch tube S3, the switch tube S4 and the switch tube S5 are all fully controlled power switch tubes, and can be insulated gate field effect tube MOSFET, insulated gate triode IGBT or other fully controlled power switch tubes.

[0053] In the implementation mode of the present application, the rectifier and filter circuit performs rectification and filtering processing to convert the AC power supply into a DC voltage, and then the full-bridge converter circuit converts the DC voltage into a high-frequency AC voltage signal and outputs it to the load output terminal to provide power output for the coating load. In one cycle, the controller controls the first group of switch tubes and the second group of switch tubes to be turned on in turn, and the controller controls the switch tube S5 to be turned on during the dead time between the first group of switch tubes and the second group of switch tubes being turned on in turn.

[0054] This application cleverly realizes the output of pulse current and voltage by controlling the timing of the switch tubes S1-S5. The output frequency can be up to twice the switching frequency of the full-bridge converter, so the generated pulse frequency range is wider, which can make the load plasma discharge more uniform. At the same time, the dead time between the first group of switch tubes and the second group of switch tubes is used to realize pulse output, which greatly reduces the current capacity and voltage stress of the switch tube S5 and improves safety. This application utilizes the current continuity of the inductor L2 and the fast switching function of the semiconductor switch tube to achieve a rapid rise in the output current, ensure the high consistency of each pulse coating energy, and further ensure the uniformity of the coating.

[0055] The following details Figure 1 Working principle of the circuit shown:

[0056] Switches S1, S2, S3 and S4 are as follows: Figure 2 The timing shown works. Figure 2 Medium and high levels represent that the switch is on, and low levels represent that the switch is off. All switches operate at a certain repetition frequency, and the maximum repetition frequency can reach 200kHz. In one working cycle, switch S1 and switch S4 are in phase, switch S2 and switch S3 are in phase, and are turned on or off at the same time. Switch S1 and switch S2 are in opposite phases, and switch S3 and switch S4 are in opposite phases. There is a dead time between switch S1 and switch S2, and between switch S3 and switch S4. Uab is the voltage waveform output by the full-bridge inverter, and Iout and Uout are the current and voltage waveforms at the output end. The turn-on time of switch S5 is the dead time between the first group of switches and the second group of switches turning on in turn.

[0057] Take a switching cycle as an example for description. Before time t0, switch tubes S1 and S4 are turned off, while switch tubes S2 and S3 are turned on. The secondary current of transformer TR1 passes through diodes BD9 and BD10, inductor L2 and coated load. At time t0, switch tubes S2 and S3 are turned on and off, and the two midpoint voltages of the full-bridge inverter are 0. The energy transferred by transformer TR1 is rapidly reduced to zero. At this time, switch tube S5 is turned on, and the current of inductor L2 continues to flow through diodes BD7-BD10 and switch tube S5. The load does not obtain the excitation current, and this state lasts until t1. Because the current consumption of inductor L2 is small, this current is basically constant.

[0058] At t1, the switch tubes S1 and S4 are turned on, and S5 is turned off. The current of the inductor L2 can immediately enter the load. The current on the capacitor C1 flows through the capacitor C2 and then flows into the primary winding of the transformer TR1. Then, it enters the rectifier diodes BD7 and BD8 through the secondary winding to supplement the energy on the inductor L2. At the same time, the voltage Uout across the load is the superposition of the voltage of the inductor L2 and the secondary voltage of the transformer, which causes the output voltage to have a peak voltage at t1. This peak voltage ensures the success of each plasma arcing and further increases the plasma ionization rate. This process continues until the end of t2.

[0059] The process at moment t2 is the same as that at moment t0, and the process at moment t3 is the same as that at moment t1, and no further description is given here. Based on the above analysis, the current Iout output by the power supply can be regarded as a rectangular pulse current, and its maximum output frequency is twice the operating frequency of the switch tubes S1-S4, so the generated pulse frequency range is wider and the load plasma discharge is more uniform. The present application very cleverly realizes the output of pulse current and voltage by controlling the control timing of the switch tubes S1-S5. The output frequency can be up to twice the switching frequency of the full-bridge converter. At the same time, the dead time of the full-bridge converter is used to realize pulse output, which greatly reduces the current capacity and voltage stress of the switch tube S5, and greatly improves safety.

[0060] It should be noted that in Figure 2 In the timing control, the controller can send a turn-on signal to the switch tube S5 during each dead time. Figure 3 As shown, the controller may also send a turn-on signal to the switch tube S5 at intervals of a dead zone, and at this time, the output current repetition frequency may be consistent with the frequency of the switch tubes S1-S4.

[0061] In some implementations, the common end of the switch tube S1 and the switch tube S2 is connected to one end of the primary winding of the transformer TR1 through a capacitor C2. The capacitor C2 is a non-polarized capacitor. Setting a capacitor C2 can be used to isolate DC current and prevent the transformer TR1 from being magnetically saturated.

[0062] It should be noted that, in the above embodiment, due to the large inductance L2 and the change of the parasitic inductance L3 on the line due to different lengths, the leading edge peak of the output voltage Uout of the power supply cannot ensure stable output. In order to solve the above problems, the present application also proposes an improved circuit, referring to Figure 4 shown.

[0063] In some embodiments, a diode D1 is further included, the drain of the switch tube S5 is connected to the cathode of the diode D1, and the anode of the diode D1 is connected to the positive electrode of the load output terminal. The diode D1 is provided to ensure unidirectional operation of the current.

[0064] In some embodiments, a diode D2 is further included, wherein the cathode of the diode D2 is connected to the positive electrode of the load output terminal, the anode of the diode D2 is connected to the negative electrode of the load output terminal, the anode of the diode D2 is connected to point A, and the cathode is connected to point B, for ensuring the continuous flow operation of the current on the load RL and the transmission line.

[0065] In some embodiments, it also includes a capacitor C3, a diode D3, a switch tube S6, a diode D4 and a resistor R1, the negative electrode of the capacitor C3 is connected to the drain of the switch tube S5, the positive electrode of the capacitor C3 is respectively connected to the cathode of the diode D3 and the drain of the switch tube S6, the anode of the diode D3 is connected to the positive electrode of the load output end, the source of the switch tube S6 is connected to the anode of the diode D4, the cathode of the diode D4 is connected to the positive electrode of the load output end through the resistor R1, and the controller is connected to the gate of the switch tube S6 to control the conduction time of the switch tube S6 during the dead time to adjust the front peak voltage of the load output end. The function of the diode D3 is to provide a channel for the capacitor C3 to charge in a forward direction. The function of the switch tube S6, the diode D4 and the resistor R1 is to provide a discharge channel for the capacitor C3, which is used to control the peak amplitude of the front voltage of the output voltage Uout.

[0066] The following details Figure 4 Working principle of the circuit shown:

[0067] Its working principle is Figure 1 It is realized on the basis of the circuit shown in the figure. At the end of time t0, capacitor C3 has a certain initial voltage. At time t1, the full-bridge converter transfers energy to transformer TR1 and obtains a positive voltage on diode BD7-DB10. This voltage is superimposed on the voltage of inductor L2. Because the superimposed voltage is greater than the initial voltage of capacitor C3, diode D3 is turned on. At this time, the output voltage between points A and B is clamped by the voltage of capacitor C3, forming a front platform of pulse voltage. Later, as the plasma coating load works, the output current increases, the output voltage decreases, and diode D3 is turned off.

[0068] After time t2, the switch tube S5 is turned on, the output voltage drops to 0, the current on the line quickly drops to zero, and the current in the inductor L2 continues to flow through the diodes BD7-BD10 and the switch tube S5; because the switch tubes S1-S4 are in the dead zone state, the transformer TR1 does not further transfer energy, and the current on the inductor L2 remains basically unchanged; at the same time, the switch tube S6 is turned on in the dead zone of the switch tube S1-S4, and part of the energy of the capacitor C3 is transferred to the resistor R1, and the voltage of the capacitor C3 will decrease, preparing for the next discharge. Therefore, the controller can control the peak voltage of the front edge of the output voltage Uout (the voltage between A and B) by controlling the on-time of the switch tube S6, and can realize the adjustable and controllable peak value of the front edge of the output pulse voltage waveform. The voltage amplitude of each pulse voltage front edge is high enough, which further ensures that the coating reaction gas and the working gas can be efficiently ionized, so that the arc is successfully started under each pulse voltage excitation.

[0069] In some embodiments, the controller can control the on and off of the switch tubes S1, S2, S3, S4, S5 and S6 through a pulse width modulation control signal (PWM), or control the on and off of the switch tubes S1, S2, S3, S4, S5 and S6 through a phase shift control signal (PSM), that is, the phases of the switch tubes S1 and S2 are opposite, and the phases of the switch tubes S3 and S4 are opposite, but the on time of the switch tubes S1 and S3 can be delayed within half a cycle. The switch tubes S5 and S6 can be turned on at the same time, or the on time of S6 can be greater than the on time of S5, but the on time of S5 and S6 cannot exceed the dead time of the switch tubes S1-S4.

[0070] The present application also relates to an abnormal discharge protection method for a pulsed DC coating power supply applied to the above-mentioned embodiment, referring to Figure 5 As shown, the following steps are included:

[0071] S101, obtaining coating status information, where the coating status information is used to indicate the working status during the coating process;

[0072] S102 . When the coating state information indicates that an abnormal discharge state exists during the coating process, the switch tubes S1 , S2 , S3 and S4 are controlled to be turned off, and the switch tube S5 is controlled to be turned on.

[0073] The coating status information can be obtained through human visual observation and then input into the controller, or it can be obtained through visual devices such as cameras through artificial intelligence or video / image recognition to obtain abnormal discharge status and then send information to the controller.

[0074] It should be noted that when abnormal discharge occurs during the coating operation, the output DC voltage decreases, while the current increases, and the value of the equivalent resistance RL of the coating load becomes smaller; if no intervention is made, the film quality will be affected, and the power supply itself will be damaged. Therefore, when an abnormal discharge state occurs, the controller controls the switch tubes S1-S4 to be turned off, and controls the switch tube S5 to be turned on, so that the output current is zero, which can achieve rapid protection of abnormal discharge of the coating and further improve safety. After entering the abnormal discharge rapid protection, it can be restarted after one or several switching cycles to enter the normal working mode.

[0075] The present application also relates to a pulsed DC coating system, comprising a coating device and the pulsed DC coating power supply of the above embodiment, wherein the coating device and the pulsed DC coating power supply are connected to each other.

[0076] The present application also relates to an electronic device, comprising the pulsed DC coating power supply of the above embodiment.

[0077] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present application.

Claims

1. A pulsed DC coating power supply, characterized in that: include: AC input terminal, used for inputting AC power; A rectifier and filter circuit, wherein the AC input terminal is connected to an input terminal of the rectifier and filter circuit; A full-bridge converter circuit, the full-bridge converter circuit comprises a switch tube S1, a switch tube S2, a switch tube S3, a switch tube S4 and a transformer TR1, the positive electrode of the output end of the rectifier and filter circuit is respectively connected to the drain of the switch tube S1 and the switch tube S3, the source of the switch tube S1 is connected to the drain of the switch tube S2, the source of the switch tube S3 is connected to the drain of the switch tube S4, the negative electrode of the output end of the rectifier and filter circuit is respectively connected to the source of the switch tube S2 and the switch tube S4, the common end of the switch tube S1 and the switch tube S2 is connected to one end of the primary winding of the transformer TR1, and the common end of the switch tube S3 and the switch tube S4 is connected to the other end of the primary winding of the transformer TR1; A single-phase bridge rectifier circuit, wherein the secondary winding of the transformer TR1 is connected to the input end of the single-phase bridge rectifier circuit; The switch tube S5, the positive electrode of the output end of the single-phase bridge rectifier circuit is connected to the drain of the switch tube S5, and the negative electrode of the output end of the single-phase bridge rectifier circuit is connected to the source of the switch tube S5 through the inductor L2; A load output end, the drain and source of the switch tube S5 are respectively connected to two ends of the load output end, and the load output end is used to connect a coating load; A controller, wherein the signal output end of the controller is respectively connected to the gates of the switch tube S1, the switch tube S2, the switch tube S3, the switch tube S4 and the switch tube S5, the switch tube S1 and the switch tube S4 are a first group of switch tubes with the same phase, the switch tube S2 and the switch tube S3 are a second group of switch tubes with the same phase, the first group of switch tubes and the second group of switch tubes have opposite phases, within one cycle, the controller controls the first group of switch tubes and the second group of switch tubes to be turned on in turn, and the controller controls the switch tube S5 to be turned on within the dead time between the first group of switch tubes and the second group of switch tubes being turned on in turn.

2. The pulsed DC coating power supply according to claim 1, characterized in that: A diode D1 is also included, the drain of the switch tube S5 is connected to the cathode of the diode D1, and the anode of the diode D1 is connected to the negative electrode of the load output end.

3. The pulsed DC coating power supply according to claim 1, characterized in that: It also includes a diode D2, wherein the cathode of the diode D2 is connected to the positive electrode of the load output terminal, and the anode of the diode D2 is connected to the negative electrode of the load output terminal.

4. The pulsed DC coating power supply according to claim 1, characterized in that: It also includes a capacitor C3, a diode D3, a switch tube S6, a diode D4 and a resistor R1, wherein the cathode of the capacitor C3 is connected to the drain of the switch tube S5, the anode of the capacitor C3 is respectively connected to the cathode of the diode D3 and the drain of the switch tube S6, the anode of the diode D3 is connected to the anode of the load output end, the source of the switch tube S6 is connected to the anode of the diode D4, the cathode of the diode D4 is connected to the anode of the load output end through the resistor R1, and the controller is connected to the gate of the switch tube S6 to control the conduction time of the switch tube S6 within the dead time to adjust the leading edge peak voltage of the load output end.

5. The pulsed DC coating power supply according to claim 4, characterized in that: The controller controls the on and off of the switch tubes S1 , S2 , S3 , S4 , S5 and S6 through a pulse width modulation control signal.

6. The pulsed DC coating power supply according to claim 4, characterized in that: The controller controls the on and off of the switch tubes S1 , S2 , S3 , S4 , S5 and S6 through a phase-shift control signal.

7. An abnormal discharge protection method for the pulsed DC coating power supply according to any one of claims 1 to 6, characterized in that: The following steps are involved: Acquiring coating state information, wherein the coating state information is used to indicate a working state during the coating process; When the coating state information indicates that an abnormal discharge state exists during the coating process, the switch tubes S1 , S2 , S3 and S4 are controlled to be turned off, and the switch tube S5 is controlled to be turned on.

8. A pulsed DC coating system, characterized in that: It comprises a coating device and a pulsed DC coating power supply as described in any one of claims 1 to 6, wherein the coating device is connected to the pulsed DC coating power supply.

9. An electronic device, characterized in that: A pulsed DC coating power supply comprising any one of claims 1 to 6.

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