High-power asymmetric bipolar pulse bias power supply, method and application thereof
阅读说明：本技术 一种大功率不对称双极性脉冲偏压电源、方法及其应用 (High-power asymmetric bipolar pulse bias power supply, method and application thereof ) 是由 窦久存 于 2019-11-06 设计创作，主要内容包括：一种大功率不对称双极性脉冲偏压电源,包括A电源、B电源、C电源,所述C电源分别与A电源、B电源的输出端连接；所述A电源电路、B电源电路的输入端分别与三相380V交流电源经过全桥整流滤波后的输出端连接,其特征为：所述C电源为包括四只可控开关管QC1,QC2,QC3,QC4形成桥臂。(A high-power asymmetric bipolar pulse bias power supply comprises a power supply A, a power supply B and a power supply C, wherein the power supply C is respectively connected with output ends of the power supply A and the power supply B; the input ends of the power supply circuit A and the power supply circuit B are respectively connected with the output end of a three-phase 380V alternating current power supply after full-bridge rectification and filtering, and the power supply circuit is characterized in that: the power supply C comprises four controllable switching tubes QC1, QC2, QC3 and QC4 to form a bridge arm.)
1. A high-power asymmetric bipolar pulse bias power supply comprises a power supply A, a power supply B and a power supply C, wherein the power supply C is respectively connected with output ends of the power supply A and the power supply B; the input ends of the power supply circuit A and the power supply circuit B are respectively connected with the output end of a three-phase 380V alternating current power supply after full-bridge rectification and filtering, and the power supply circuit is characterized in that: the power supply C comprises four controllable switching tubes QC1, QC2, QC3 and QC4 to form a bridge arm.
2. The high power asymmetric bipolar pulse bias power supply as claimed in claim 1, wherein: the power supply A comprises a DC/AC/DC converter I, a DC/AC/DC converter II, a DC/AC/DC converter III and a power supply A gear switching circuit; the input ends of the DC/AC/DC converter I, the DC/AC/DC converter II and the DC/AC/DC converter III are respectively connected with the rectifying and filtering circuit, and the output ends of the DC/AC/DC converter I, the DC/AC/DC converter II and the DC/AC/DC converter III are respectively connected with the input end of the power supply gear switching circuit A.
3. The high power asymmetric bipolar pulse bias power supply as claimed in claim 2, wherein: the DC/AC/DC converter I comprises a full-bridge inverter 1, a high-frequency transformer T1, a high-frequency rectifier D1, a filter inductor L1 and a filter capacitor C1; a full-bridge inverter is formed by four IGBT tubes of Q1a, Q1b, Q1c and Q1 d; the output end of the full-bridge inverter is connected with the primary side of a high-frequency transformer T1; the secondary side of the high-frequency transformer T1 is connected with a high-frequency rectifier D1; the output of the high-frequency rectifier D1 is connected with a filter inductor L1 and a filter capacitor C1.
4. The high power asymmetric bipolar pulse bias power supply as claimed in claim 1, wherein: and the control circuit corresponding to the power supply A synchronously controls the outputs of the DC/AC/DC converter I, the DC/AC/DC converter II and the DC/AC/DC converter III to ensure that the output characteristics are completely the same.
5. The high power asymmetric bipolar pulse bias power supply as claimed in claim 2, wherein: the A power supply gear switching circuit comprises a contactor and a control circuit; the contactors comprise three identical contactors KM1, KM2 and KM 3; the contactors KM1, KM2 and KM3 respectively comprise two normally open contacts 1-2 and 5-6; the contactor KM1 normally-open contact terminal 1 is connected with the output positive electrode of the DC/AC/DC converter II; the contactor KM1 normally-open contact terminal 5 is connected with the output positive electrode of the DC/AC/DC converter III; the contactor KM1 normally open contact terminal 2 and the normally open contact terminal 6 are connected with the positive pole of the DC/AC/DC converter I at one point and serve as the output positive pole of the power supply A; the contactor KM2 normally-open contact terminal 1 is connected with the output positive electrode of the DC/AC/DC converter II; the contactor KM2 normally-open contact terminal 2 is connected with the output negative electrode of the DC/AC/DC converter I; the contactor KM2 normally open contact terminal 5 is connected with the output negative electrode of the DC/AC/DC converter II; the contactor KM2 normally-open contact terminal 6 is connected with the positive electrode of the DC/AC/DC converter III; the contactor KM3 normally-open contact terminal 1 is connected with the negative electrode of the DC/AC/DC converter I; the contactor KM3 normally open contact terminal 5 is connected with the negative electrode of the DC/AC/DC converter II; and the contactor KM3 normally open contact terminal 2, the normally open contact terminal 6 and the negative pole of the DC/AC/DC converter III are connected at one point and used as the negative pole of the A power supply output.
6. A high power asymmetric bipolar pulse bias power supply as claimed in claim 1, wherein: the power supply B comprises a DC/AC/DC converter IV, and the DC/AC/DC converter IV comprises a full-bridge inverter 4 formed by IGBT tubes, a high-frequency transformer TB, a high-frequency rectifier DB, a filter inductor LB and a filter capacitor CB 2; the input end of the high-frequency transformer TB is connected with the output end of the full-bridge inverter 4; the output end of the high-frequency transformer TB is connected with the input end of the high-frequency rectifier DB; the output end of the high-frequency rectifier DB is connected with a filter inductor LB and a filter capacitor CB2, and a control circuit corresponding to a power supply B realizes the on-off of an IGBT tube in the inverter by controlling the full-bridge inverter 4.
7. The high power asymmetric bipolar pulse bias power supply as claimed in claim 1, wherein: a freewheeling high-frequency diode DC1, DC2, DC3 and DC4 are connected in parallel between the drain and the source of each controllable switch tube in the C power supply; the control electrode of the controllable switching tube is connected with a control circuit of the power supply C to control the on and off of the controllable switching tube; the high-frequency LED drive circuit also comprises a high-frequency diode DC5, a high-frequency diode DC6, filter capacitors CC1, CC2, CC3, resistors RC1 and RC2 and an inductor LC; one end of the RC1 is connected with a power supply A after being connected with a DC5 in parallel, and the other end of the RC1 is connected with a power supply B through an inductor LC; the cathode of the DC6 is connected with the CC3 in series and then connected with the low potential of the power supply C, and the anode of the DC6 is connected with the anode of the DC 5; one end of the resistor RC2 is connected with the cathode of the DC6, and the other end of the resistor RC2 is connected with a power supply B; CC1 is connected in parallel with the input end of the C power supply, and CC2 is connected at the anode of DC6 and two ends of the low potential of the C power supply.
8. The high power asymmetric bipolar pulse bias power supply as claimed in claim 7, wherein: the C power supply has three output modes: the power supply comprises a direct current output mode, a unipolar pulse output mode and an asymmetric bipolar pulse output mode, wherein the direct current output mode is that the duty ratio of a power supply pulse is set to be 100%, and the output voltage and current of a power supply A are controlled, namely the output voltage and current of a power supply C can be adjusted; the unipolar pulse output mode is that the C power supply outputs unipolar pulses, and the frequency output by the C power supply and the duty ratio of positive and negative pulses of the unipolar pulses are changed by changing the period and the duty ratio of control pulses output by the C power supply control circuit; the asymmetric bipolar pulse output mode is that the positive and negative amplitudes of the bipolar pulse output by the power supply C are correspondingly changed by changing the output amplitude of the power supply A, B; the period and the duty ratio of the control pulse output by the C power supply control circuit are changed, so that the frequency of the C power supply output and the duty ratio of positive and negative pulses of the bipolar pulse are changed, and the aim of asymmetric output is fulfilled.
9. A method for applying a high power asymmetric bipolar pulse bias power supply, comprising the high power asymmetric bipolar pulse bias power supply as claimed in any one of claims 1-8, wherein: when a DC5 isolating diode in the C power supply blocks a controllable switching tube QC1 and a QC2 high-voltage side and is switched off, a freewheeling loop of high-frequency diodes DC1 and DC4 only allows the anode directions of a capacitor CC1 and an electrolytic capacitor CA to be charged, the diodes DC2 and DC3 are switched on by reverse electromotive force generated by switching off the low-voltage sides of the switching tube QC2 and QC3, on one hand, the residual energy is clamped through the capacitor CC2, the residual energy is clamped through the diode DC3 and the capacitor CC3, the energy stored in the capacitor CC3 is discharged to a low-voltage side filter capacitor CB through a resistor RC2, on the other hand, due to the capacity limitation of the capacitor CC2, reverse electromotive force generated by the inductor LC during the turn-off period of the switching tubes QC2 and QC3 is accumulated through a period, the potential of the capacitor CC2 is higher than that of the electrolytic capacitor CB and even the electrolytic capacitor CA, the diode DC3 consumes a part of energy on the resistor RC2 through a follow current channel of the resistor RC2, and the other part of energy is charged to the capacitor CC3 and then is discharged to the low-voltage side filter capacitor CB through the resistor RC 2; the diode DC5 ensures that the potential of the capacitor CC2 does not exceed the electrolytic capacitor CA under extreme conditions, namely the safety of low-voltage side bridge arms of the switch tubes QC3 and QC4 is ensured, and the potential of the end of the electrolytic capacitor CA releases part of energy to the load end RL through the resistor RC1 during the conduction period of the low-voltage sides of the switch tubes QC2 and QC3 to ensure the potential stability of the two ends of the electrolytic capacitor CA; all the energy leaked to the capacitor CB will be discharged to the load end RL during the conduction of the low-voltage sides of the switching tubes QC2 and QC 3.
10. A bias power supply applied to the field of vacuum multi-arc ion plating or vacuum magnetron sputtering ion plating is characterized in that: the power supply comprises a high power asymmetric bipolar pulsed bias power supply as claimed in any one of claims 1 to 8.
Technical Field
The invention relates to power supply equipment used in the technical field of vacuum multi-arc ion plating, in particular to a high-power asymmetric bipolar pulse bias power supply.
Background
The multi-arc ion plating is to take a metal evaporation source (target material) as a cathode, evaporate and ionize the target material to form space plasma through arc discharge between the target material and an anode shell in a vacuum environment, and perform deposition plating of metal, metal compounds and the like on a workpiece under the action of bias voltage of a substrate to form a high-temperature-resistant and corrosion-resistant decorative coating with a specific color; or the superhard self-lubricating coating formed by metal, metal alloy, silicon and nitride and carbide of the metal alloy is used for the abrasion-resistant environment such as cutting tools, drilling tools, dies, turbine blades, oil-free lubrication and the like. The bias voltage is an important process parameter of multi-arc ion plating and other vacuum plasma coating, and can remove gas and pollutants adsorbed on the surface of a workpiece during pre-bombardment before plating; during deposition, the bias voltage in turn energizes the ions to tightly bond the substrate to the film. The traditional unipolar bias power supply is easy to accumulate charge discharge burn workpieces due to unipolar bias, and the unipolar bias causes radial accumulation of particles and cannot enhance the pinning strength inside the particles, so that the loose binding force of a film layer is poor. The bipolar pulse bias power supply can output positive and negative bidirectional pulses, the negative pulses can neutralize charge accumulation on the insulating layer, workpiece ignition is effectively inhibited, and the positive pulses carry out bombardment cleaning and deposition. The positive and negative alternate pulses obtain more obvious ion bombardment effect in the film deposition process, the internal stress of the film and the binding force between the film and a substrate are obviously improved, meanwhile, ultrasonic waves generated based on a geomagnetic field have good workpiece self-cleaning effect, and the film layer is fine, smooth and clean and does not cause dust.
As the application of multi-arc ion plating in various fields is increasingly expanded, a vacuum coating chamber of decorative coating equipment is also rapidly expanded, at present, 116 arc targets are matched with large coating equipment with a vacuum chamber diameter of 4 meters and a height of 6.8 meters, 8A bias current is loaded according to each arc target, 928A is needed for coating deposition working current, 220V is calculated for coating deposition bias, 204KW bias power is needed in total, the dynamic characteristic of arc discharge is considered, the needed bias power is at least over 240KW, and a workpiece is applied with a bias voltage of over 400V in a bombardment cleaning working process. With the demands of industrial development, the requirements for output voltage and current are higher.
Disclosure of Invention
The existing large-scale vacuum multi-arc ion plating bias power supply always adopts direct current or pulse direct current, and because a series of advantages of the bipolar pulse bias power supply are not provided, workpiece burn caused by charge accumulation of a plated workpiece often occurs in practical application, and in addition, the bonding force of a film layer is poor, and the purity of the film layer is poor. Aiming at the defects in the prior art, the invention discloses a high-power asymmetric bipolar pulse bias power supply, which adopts the following technical scheme:
the power supply C is respectively connected with the output ends of the power supply A and the power supply B; the input ends of the power supply circuit A and the power supply circuit B are respectively connected with the output end of a three-phase 380V alternating current power supply after full-bridge rectification and filtering, and the power supply circuit is characterized in that: the power supply C comprises four controllable switching tubes QC1, QC2, QC3 and QC4 to form a bridge arm.
Preferably: the power supply A comprises a DC/AC/DC converter I, a DC/AC/DC converter II, a DC/AC/DC converter III and a power supply A gear switching circuit; the input ends of the DC/AC/DC converter I, the DC/AC/DC converter II and the DC/AC/DC converter III are respectively connected with the rectifying and filtering circuit, and the output ends of the DC/AC/DC converter I, the DC/AC/DC converter II and the DC/AC/DC converter III are respectively connected with the input end of the power supply gear switching circuit A.
Preferably: the DC/AC/DC converter I comprises a full-bridge inverter 1, a high-frequency transformer T1, a high-frequency rectifier D1, a filter inductor L1 and a filter capacitor C1; the full-bridge inverter 1 consists of four IGBT tubes Q1a, Q1b, Q1c and Q1 d; the output end of the full-bridge inverter 1 is connected with the primary side of a high-frequency transformer T1; the secondary side of the high-frequency transformer T1 is connected with a high-frequency rectifier D1; the output of the high-frequency rectifier D1 is connected with a filter inductor L1 and a filter capacitor C1.
Preferably: and the control circuit corresponding to the power supply A synchronously controls the outputs of the DC/AC/DC converter I, the DC/AC/DC converter II and the DC/AC/DC converter III to ensure that the output characteristics are the same.
Preferably: the A power supply gear switching circuit comprises a contactor and a control circuit; the contactors comprise three identical contactors KM1, KM2 and KM 3; the contactors KM1, KM2 and KM3 respectively comprise two normally open contacts 1-2 and 5-6; the contactor KM1 normally-open contact terminal 1 is connected with the output positive electrode of the DC/AC/DC converter II; the contactor KM1 normally-
Preferably: the power supply B comprises a DC/AC/DC converter IV, and the DC/AC/DC converter IV comprises a full-bridge inverter 4 formed by IGBT tubes, a high-frequency transformer TB, a high-frequency rectifier DB, a filter inductor LB and a filter capacitor CB 2; the input end of the high-frequency transformer TB is connected with the output end of the full-bridge inverter 4; the output end of the high-frequency transformer TB is connected with the input end of the high-frequency rectifier DB; the output end of the high-frequency rectifier DB is connected with a filter inductor LB and a filter capacitor CB2, and a control circuit corresponding to a power supply B realizes the on-off of an IGBT tube in the inverter by controlling the full-bridge inverter 4.
Preferably: the C power supply comprises four controllable switching tubes QC1, QC2, QC3 and QC4 which form bridge arms, and a freewheeling high-frequency diode is connected between the drain and the source of each controllable switching tube in parallel; the control electrode of the controllable switching tube is connected with a control circuit of the power supply C to control the on and off of the controllable switching tube; the high-frequency LED drive circuit also comprises a high-frequency diode DC5, a high-frequency diode DC6, filter capacitors CC1, CC2, CC3, resistors RC1 and RC2 and an inductor LC; one end of the RC1 is connected with a power supply A after being connected with a DC5 in parallel, and the other end of the RC1 is connected with a power supply B through an inductor LC; the cathode of the DC6 is connected with the CC3 in series and then connected with the low potential of the power supply C, and the anode of the DC6 is connected with the anode of the
Preferably: the C power supply has three output modes: the power supply comprises a direct current output mode, a unipolar pulse output mode and an asymmetric bipolar pulse output mode, wherein the direct current output mode is that the duty ratio of a power supply pulse is set to be 100%, and the output voltage and current of a power supply A are controlled, namely the output voltage and current of a power supply C can be adjusted; the unipolar pulse output mode is that the C power supply outputs unipolar pulses, and the frequency output by the C power supply and the duty ratio of positive and negative pulses of the unipolar pulses are changed by changing the period and the duty ratio of control pulses output by the C power supply control circuit; the asymmetric bipolar pulse output mode is that the positive and negative amplitudes of the bipolar pulse output by the power supply C are correspondingly changed by changing the output amplitude of the power supply A, B; the period and the duty ratio of the control pulse output by the C power supply control circuit are changed, so that the frequency of the C power supply output and the duty ratio of positive and negative pulses of the bipolar pulse are changed, and the aim of asymmetric output is fulfilled. .
The invention also discloses an application method of the high-power asymmetric bipolar pulse bias power supply, which is characterized by comprising the high-power asymmetric bipolar pulse bias power supply.
The invention also discloses a power supply applied to the field of vacuum multi-arc ion plating, which is characterized in that: the power supply is an application method of a high-power asymmetric bipolar pulse bias power supply.
Has the advantages that:
the invention can realize various combined working modes of independent adjustable frequency and duty ratio, adjustable main and auxiliary power supply voltage and real-time direct current and pulse conversion; the adjustable parameters are increased, the output waveform and the characteristics of the power supply can be conveniently debugged, and the purpose of high-power output can be achieved through the output parallel topology.
Drawings
FIG. 1 is a block diagram of the overall structure of a high-power asymmetric bipolar pulse bias power supply according to the present invention.
FIG. 2 is a block diagram of the circuit structure of the high-power asymmetric bipolar pulse bias power supply of the present invention.
FIG. 3 is a power supply circuit diagram of a high power asymmetric bipolar pulse bias power supply C according to the present invention.
FIG. 4 is a timing diagram of the output pulses of the high-power asymmetric bipolar pulse bias power supply of the present invention, wherein: (a) in the dc output mode: the output voltage waveform of the power supply C when the pulse duty ratio of the power supply A is modulated to be 100%; (b) in unipolar pulse output modes: a schematic diagram I of a C power output voltage waveform when the pulse duty ratio modulation of the A power is 50%, a schematic diagram II of the C power output voltage waveform when the pulse duty ratio modulation of the A power is 10%, and a schematic diagram III of the C power output voltage waveform when the pulse duty ratio modulation of the A power is 90%; (c) in an asymmetric bipolar pulse output mode: the power supply comprises a power supply A, a power supply B, a power supply C, a power supply.
FIG. 5 shows a high power asymmetric bipolar pulse bias power supply according to the present invention: (a) the power supply comprises a power supply gear switching circuit A, a power supply gear switching circuit A and a power supply gear switching circuit B, wherein the power supply A is in low-voltage output, and the power supply A is in high-voltage output.
Detailed Description
The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. See fig. 1-5 for illustration.
As shown in fig. 1-2. The high-power asymmetric bipolar pulse bias power supply comprises a power supply A, a power supply B, a power supply C and a control circuit corresponding to the power supplies; it is characterized in that: the power supply C is respectively connected with the output ends of the power supply A and the power supply B; the control circuit is connected with the comprehensive control and data display module; and the input ends of the power supply circuit A and the power supply circuit B are respectively connected with the output ends of a three-phase 380V alternating-current power supply after rectification and filtering.
The power supply A comprises a three-phase full-bridge rectifying circuit, a filter capacitor, a DC/AC/DC converter I, a DC/AC/DC converter II, a DC/AC/DC converter III, a power supply gear switching circuit A and a power supply control circuit A which are sequentially connected. The DC/AC/DC converter I comprises a full-bridge inverter 1, a high-frequency transformer T1, a high-frequency rectifier D1, a filter inductor L1 and a filter capacitor C1; the full-bridge inverter 1 is composed of IGBT tubes Q1a, Q1b, Q1c and Q1d which are connected in sequence; the output end of the full-bridge inverter 1 is connected with the primary side of a high-frequency transformer T1; the secondary side of the high-frequency transformer T1 is connected with a high-frequency rectifier D1; the output of the high-frequency rectifier D1 is connected with a filter inductor L1 and a filter capacitor C1; the power supply control circuit A controls Q1a and Q1D to be switched on, Q1b and Q1C to be switched off, then Q1a and Q1D to be switched off, Q1b and Q1C to be switched on, the direct current is converted into high-frequency alternating current through cyclic conversion, a transformer T1 is used for isolating a primary side and a secondary side, the high-frequency alternating current is converted into pulsating direct current through a high-frequency rectifier bridge D1, and finally the smooth direct current is obtained through the filtering action of an inductor L1 and a capacitor C1 a; the circuit output is provided with an LEMVA Hall voltage and current sensor, and the power supply control circuit A adjusts the on-off time of each working period of the full-bridge inverter 1 by comparing the difference value of an output signal and a set signal so as to adjust the output voltage of the DC/AC/DC converter I;
the DC/AC/DC converter II comprises a full-bridge inverter 2, a high-frequency transformer T2, a high-frequency rectifier D2, a filter inductor L2 and a filter capacitor C2; the full-bridge inverter 2 consists of IGBT tubes Q2a, Q2b, Q2c and Q2d which are connected in sequence; the output end of the full-bridge inverter 2 is connected with the primary side of a high-frequency transformer T2; the secondary side of the high-frequency transformer T2 is connected with a high-frequency rectifier D2; the output of the high-frequency rectifier D2 is connected with a filter inductor L2 and a filter capacitor C2; the control and output mode of the DC/AC/DC converter II is the same as that of the DC/AC/DC converter I; the DC/AC/DC converter III comprises a full-bridge inverter 3, a high-frequency transformer T3, a high-frequency rectifier D3, a filter inductor L3 and a filter capacitor C3; the full-bridge inverter 3 consists of IGBT tubes Q3a, Q3b, Q3c and Q3d which are connected in sequence; the output end of the full-bridge inverter 3 is connected with the primary side of a high-frequency transformer T3; the secondary side of the high-frequency transformer T3 is connected with a high-frequency rectifier D3; the output of the high-frequency rectifier D3 is connected with a filter inductor L3 and a filter capacitor C3. The control and output mode of the DC/AC/DC converter III is the same as that of the DC/AC/DC converter I; the full-bridge inverters 1, 2 and 3, the high-frequency transformers T1, T2 and T3, the high-frequency rectifiers D1, D2 and D3, the filter inductors L1, L2 and L3 and the filter capacitors C1, C2 and C3 have the same element parameters and the same mutual connection mode; the power supply control circuit A synchronously controls the output of the DC/AC/DC converter I, the DC/AC/DC converter II and the DC/AC/DC converter III to ensure that the output characteristics are completely the same; the power source gear switching circuit A comprises a contactor and a control circuit, and is shown in fig. 5.
The contactors comprise three identical contactors KM1, KM2 and KM 3; the contactors KM1, KM2 and KM3 respectively comprise two contacts 1-2 and 5-6; the contact terminal 1 of the contactor KM1 is connected with the output positive electrode of the DC/AC/DC converter II; the
The power supply B consists of a filter capacitor and a DC/AC/DC converter IV which are sequentially connected; the DC/AC/DC converter IV comprises a full-bridge inverter 4 formed by IGBTs, a high-frequency transformer TB, a high-frequency rectifier DB, a filter inductor LB, a filter capacitor CB2 and a power supply B inverter control circuit; the full-bridge inverter 4 consists of IGBT tubes QB1, QB2, QB3 and QB4 which are connected in sequence; the input end of the high-frequency transformer TB is connected with the output end of the full-bridge inverter 4; the output end of the high-frequency transformer TB is connected with the input end of the high-frequency rectifier DB; the output end of the high-frequency rectifier DB is connected with a filter inductor LB and a filter capacitor CB 2; the B inverter control circuit converts direct current into high-frequency alternating current by controlling alternate conduction and disconnection of QB1 and QB4, QB2 and QB3, a primary transformer TB isolates the secondary, a high-frequency rectifier bridge DB converts the high-frequency alternating current into pulsating direct current, and finally the smooth direct current is obtained under the filtering action of an inductor LB and a capacitor CB 2; the output voltage of the B power supply is regulated by regulating the on and off time of the full-bridge inverter 4 per period, and the voltage of the negative pulse part output by the C power supply is further regulated.
The power supply C is composed of the elements shown in FIG. 3, the power supply A side is a high voltage side, the power supply B side is a low voltage side, and OA and OB are power supply output terminals. QC1, QC2, QC3 and QC4 are controllable switching tubes (such as IGBTs, MOSFETs and the like), DC1, DC2, DC3, DC4, DC5 and DC6 are high-frequency diodes, CC1 and CC2 are filter capacitors, CC3 is an absorption energy storage capacitor, RC1 and RC2 are resistors, and LA, LB and LC are inductors. The purpose of this topology is to ensure that the high and low voltage side potentials do not charge the two side half-legs to equal voltage state through freewheeling diodes DC1, DC4 or DC2, DC3 due to the back emf of the output cable distributed inductance LO during diagonal turn-off. DC5 isolation diode blocks DC1, DC4 freewheeling circuit when QC1, QC2 high-voltage side is turned off, only CC1 and CA direction are allowed to charge, DC2, DC3 are turned on by reverse electromotive force generated when QC2, QC3 low-voltage side is turned off, on one hand, surplus energy is clamped through CC2, the surplus energy is clamped through DC3 and large capacitor CC3, CC3 stores energy and then is discharged to low-voltage side filter capacitor CB through RC2, on the other hand, due to the capacity limitation of CC2, reverse electromotive force generated by LC in the turn-off period of QC2, QC3 is accumulated through cycle, the potential of CC2 is higher than that of CB even CA, DC3 consumes a part of energy on RC2 through RC2 freewheeling channel, and the other part is charged to CC3 and then is discharged to low-voltage side filter capacitor CB through RC 2. The RC1 is designed on a C power supply, the purpose of the invention is to ensure that the potential of the CC2 does not exceed CA under extreme conditions, namely the safety of low-voltage side bridge arms of QC3 and QC4 is ensured, and the potential of a CA end is ensured to be stable by releasing part of energy to a load end RL through the RC1 during the conduction of the low-voltage sides of QC2 and QC 3. All the energy drained to the capacitor CB will be discharged to the load end RL during the conduction of the low voltage side of QC2 and QC 3. The C power supply control circuit controls the on and off of QC1, QC4, QC2 and QC3 of the C power supply to realize three output modes: a direct current output mode, a unipolar pulse output mode, and an asymmetric bipolar pulse output mode.
Fig. 4 is a pulse sequence of the power supply according to embodiment C of the present invention.
The direct current output mode is as follows: the C power supply control circuit controls QC1 and QC4 to be in a conducting state QC2 and QC3 to be in a cut-off state all the time, the OA output end of the C power supply is connected with the positive pole of the power supply A, the OB output end of the C power supply is connected with the negative pole of the power supply A, at the moment, the power supply works in a direct current output mode, namely, the duty ratio of power supply pulses is set to be 100%, and the output voltage and current of the power supply A can be controlled to adjust the output voltage and current of the. As shown in fig. 4 (a).
The unipolar pulse output mode: fig. 4(b) shows output waveforms for three pulse duty conditions. Taking the duty ratio of the pulse a of 50% in fig. 4(b) as an example, the power supply control circuit C controls the power supply control circuit to be in the on state t1 at t1, the on state t2 at t 4, the off state at t3 at t2 and at QC3, the OA output terminal of the power supply C is connected to the positive pole of the power supply a, the OB output terminal of the power supply C is connected to the negative pole of the power supply a, and the amplitude output by the power supply C is the output amplitude of the power supply a; the C power supply control circuit controls t1 time QC1, QC4 to be in cut-off state t2, t3 time QC2, QC3 to be in cut-off state, and the C power supply is in the state of stopping output; the C power supply control circuit controls t1, t2 time QC1, QC4 to be in cut-off state t3 time QC2, QC3 to be in the conducting state, the OA output end of the C power supply is connected with the positive pole of the B power supply, the OB output end of the C power supply is connected with the negative pole of the B power supply, the output voltage of the B power supply is set to be 0, and the amplitude value output by the C power supply is 0 at the moment; the C power supply control circuit controls the three states to change periodically, the C power supply outputs unipolar pulses, and the frequency output by the C power supply and the duty ratio of the unipolar pulses are changed by changing the period and the duty ratio of the control pulses output by the C power supply control circuit. Other pulse duty ratios are similar to this operation, and fig. 4(B) B and 4(B) C show the duty ratios of 10% and 90%.
The asymmetric bipolar pulse output mode: the output waveforms for the three pulse duty cycle conditions are given in fig. 4 (c). Taking the pulse duty ratio of 50% as an example, the C power supply control circuit controls the power supply control circuit to be in a conducting state at t1 time QC1, QC4, a conducting state at t2, a time at t3 QC2 and a time at QC3 to be in a cut-off state, the OA output end of the C power supply is connected with the positive pole of the power supply A, the OB output end of the C power supply is connected with the negative pole of the power supply A, and the amplitude output by the C power supply is the; the C power supply control circuit controls t1 time QC1, QC4 to be in cut-off state t2, t3 time QC2, QC3 to be in cut-off state, and the C power supply is in the state of stopping output; the C power supply control circuit controls t1, t2 time QC1, QC4 to be in cut-off state t3 time QC2, QC3 to be in the conducting state, the OB output end of the C power supply is connected with the positive pole of the B power supply, the OA output end of the C power supply is connected with the negative pole of the B power supply, the amplitude value output by the C power supply is the output amplitude value of the B power supply at the moment, but the polarity is opposite to the former; the C power supply control circuit controls the three state periods to change alternately, and the C power supply outputs bipolar pulses. Changing A, B the output amplitude of the power supply will change the positive and negative amplitudes of the bipolar pulse output by the C power supply; the period and the duty ratio of the control pulse output by the C power supply control circuit are changed, so that the frequency output by the C power supply and the duty ratio of positive and negative pulses of the bipolar pulse are changed, and the aim of asymmetric output is fulfilled. Fig. 4(B) B and 4(B) C show the duty ratios of 10% and 90%.
The power control circuit is further described as follows: the power supply control circuit A is used for controlling the power supply A to generate three groups of 0-rated value direct current power supply DC/AC/DC converters I, DC/AC/DC converters II and DC/AC/DC converters III, and controlling the series connection or parallel connection of the three groups of power supplies through a high-voltage/low-voltage conversion (power supply output) circuit, so that the power supply A generates required high-voltage or low-voltage heavy current in different working periods; the B power supply control circuit is used for controlling a B power supply to generate a 0-rated value direct current power supply B (DC/AC/DC converter B); the C power supply control circuit is used for adjusting the conducting time proportion of QC1, QC4, QC3 and QC2 shown in the figure 3 to realize different width output of the A power supply and the B power supply, so that asymmetrical output on the width is realized, and when QC1 and QC4 are always turned on, the direct current state output of the A power supply is realized; the comprehensive control and data display are used for distributing amplitude values required by the power supply A and the power supply B, controlling the gear switching of the power supply A, controlling different working states of the power supply C, collecting A, B, C data such as current-voltage duty ratio of the power supply and the like for display, and are also responsible for data interaction with an upper computer.
As described in the background art, the power level of the 240KW bias power supply can not be realized by a single C power supply due to the structural problem, the actually applied power expansion circuit is three identical 80kW C power supplies, namely a C power supply I, a C power supply II and a C power supply III, the corresponding input ends of the three power supplies are connected with the output end of the power supply A and the output end of the power supply B, and the output ends of the three power supplies are connected in parallel to serve as output, so that the purpose of power expansion is achieved. The C power supply control circuit transmits positive and negative pulse signals to three same C power supplies through six optical fibers of the same type, and synchronously controls output and stop. The power supply control circuit A, the inverter control circuit B and the power supply control circuit C are controlled by current and voltage closed loops and are uniformly controlled by a comprehensive control and display circuit.
Through the control scheme, a plurality of combined working modes of independent adjustment of frequency and duty ratio, independent adjustment of positive and negative pulse amplitude and real-time conversion of direct current, unipolar pulse and bipolar pulse can be realized, the voltage level of the positive pulse output by the power supply can be changed by changing the output gear of the power supply A, and the power supply can work in a bombardment cleaning high-voltage state and a coating deposition high-current state by matching with the parallel connection of the power supply C. The positive pulse output by the invention can neutralize the charge accumulation on the insulating layer, effectively inhibit the ignition of the workpiece, and the negative pulse carries out bombardment cleaning and deposition, thereby overcoming the defect that the unipolar pulse bias is easy to accumulate the charge.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
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