CN205249079U

CN205249079U - High pressure plasma power

Info

Publication number: CN205249079U
Application number: CN201520626104.3U
Authority: CN
Inventors: 戴斌; 王贤斌; 陶忠元
Original assignee: Nanjing Wei Deng Plasma Science & Technology Equipment Co Ltd
Current assignee: Nanjing Wei Deng Plasma Science & Technology Equipment Co Ltd
Priority date: 2015-08-19
Filing date: 2015-08-19
Publication date: 2016-05-18
Anticipated expiration: 2025-08-19

Abstract

The utility model relates to a high pressure plasma power, a serial communication port, plasma power supply includes rectifier circuit, full -bridge circuit, exchanges mutual -inductor, high voltage transformers, auxiliary electrical power source, frequency converting circuit, sampling circuit, power conditioning circuitry and current feedback control circuit, rectifier circuit will input the alternating current and become direct current 300V voltage, connect high voltage transformers through full -bridge circuit, interchange mutual -inductor, and tens kilovolts of high -tension electricities of transformer output form gas discharge, and the energy concentrating of discharge gas forms plasma. It passes through the sampling circuit junction current feedback control circuit to exchange the mutual -inductor, current feedback control circuit is through frequency conversion circuit connection full -bridge circuit, the power conditioning circuitry junction current feedback control circuit, auxiliary electrical power source is flyback switching power supply, provides + 12V dc operation voltage for the circuitry.

Description

High pressure plasma power supply

Technical field

The utility model relates to a kind of power supply, is specifically related to a kind of high pressure plasma power supply, belongs to plasma technology field.

Background technology

The essence of plasma technology is gas discharge，Reach enough energy and just form electric arc, electric arc again can be more concentrated by compression, and degree of ionization is larger, and flow velocity is faster, and this compression arc is commonly referred to plasma technology，Along with the extensive use of plasma technique, stability and the reliability of high pressure plasma power supply are more and more concerned by people. Domestic widely used plasma electrical source at present, the half-bridge hard switching open-loop control technology that great majority use IGBT to drive, because high-tension transformer secondary voltage is high to several more than thousand ten thousand volts even, sampling and isolation are very difficult, so general design is used open loop control conventionally.

The feature of above-mentioned technology is that principle is simple, and technical difficulty is low, is convenient to technical staff and grasps and use, easy to maintenance. But IGBT device has limited the raising of frequency, conventionally, below 20kHz, improve switching frequency, to the significant volume of transformer that for example can reduce of the quality of Switching Power Supply, output voltage stability is good etc. And while working under low frequency, the pulsation of current that half-bridge electric capacity bears causes greatly heating, the defect of hard switching technology is that switching tube work wave is square wave, switch moment produces higher hamonic wave, make the switching loss of power semiconductor switch large, heating is severe, existing measure is, adopt energy-dissipating type RC absorbing circuit, on heater members, strengthen radiator and air blast cooling, but RC absorbs and just loss transferred on power resistor, this loss reduces power-efficient, and electronic device caloric value size has determined the life-span that this device uses. Use open loop control, plasma is easily subject to the impact of power network fluctuation and the variation of industry spot Compressed Gas source of the gas, and stability also makes relatively poor. In actual use, if when user is higher to product quality requirement, normally, by being equipped with the ancillary methods such as AC voltage regulator, make up the deficiency of the stability of power supply own. In maintenance service, often find that IGBT damages, the overheated and blackout etc. of the quick-fried slurry of the large electric capacity of half-bridge and RC absorption circuit resistance, serious when overheated printed circuit board (PCB) burn. The frequent appearance of these problems, all exposes the deficiency of principle design, makes reliability lower, has affected the normal use of equipment. Visible, plasma electrical source has affected the development of plasma technique, substitutes existing power supply in the urgent need to the stable efficient plasma electrical source again of one.

Utility model content

In order to solve the problem of above-mentioned existence, the utility model discloses a kind of high pressure plasma power supply, this technical scheme adopts a kind of full-bridge soft-switching closed loop high voltage source, utilize leakage inductance and the distribution capacity composition Voltage Series resonance circuit of high-tension transformer, make the electric current that flows through switching tube become sine wave instead of square wave, conditioned LC parameter makes switching tube conducting or shutoff in the time of sinusoidal current zero passage, thereby greatly lowers switching loss. This soft switch technique is suitable for high pressure low current type high power switching power supply, can make switching loss greatly reduce, and power-efficient significantly improves, and meanwhile, device loss is little, and caloric value is little, the corresponding raising of device lifetime and reliability. This full-bridge power supply uses MOS power device, and switching frequency is more than 50kHz.

To achieve these goals, the technical solution of the utility model is as follows, high pressure plasma power supply, it is characterized in that, described plasma electrical source comprises rectification circuit, full-bridge circuit, D.C mutual-inductor, high-tension transformer, accessory power supply, frequency changer circuit, sample circuit, power conditioning circuitry and Current Feedback Control Circuit, described rectification circuit passes through full-bridge circuit, ac sensor connects high-tension transformer, described D.C mutual-inductor connects Current Feedback Control Circuit by sample circuit, described Current Feedback Control Circuit connects full-bridge circuit by frequency changer circuit, described power conditioning circuitry connects Current Feedback Control Circuit, described accessory power supply provides direct-current working volts for circuitry.

As a kind of improvement of the present utility model; full bridge soft switch circuit comprises full-bridge circuit, full bridge driving circuit, energy storage and filter capacitor, power valve protective circuit, block isolating circuit; wherein Q19 ~ Q22 forms full-bridge circuit, C70, and C71 is energy storage and filter capacitor; Z5 ~ Z8 and C50 ~ C53 forms power valve protective circuit; C37 ~ C40, C42 ~ C45, R54; R55 forms block isolating circuit, and circuit output connects high-tension transformer. Full bridge driving circuit output G1 ~ G4Si road signal, driven MOS power tube Q19 ~ Q22 respectively.

As a kind of improvement of the present utility model, in described D.C mutual-inductor, CSP1 is that D.C mutual-inductor is elementary, and CPS1 is level.

As a kind of improvement of the present utility model, described sample circuit comprises full-wave rectifying circuit and filtering, nominal load circuit, wherein D26, and D27, D28, D29 form full-wave rectifying circuit, C41, R53 forms filtering, nominal load circuit. Their common composition current sampling circuits, when circuit working, current transformer, for the working alternating current on the former limit of high-tension transformer input of sampling, after over-sampling circuit, forms and changes corresponding current signal PC with the operating current of transformer primary side. Sample rate current PC amplitude is less, through R44, and C33 elimination clutter, then deliver to amplifier U4B and R40, and R42, C22, amplifies little current signal.

As a kind of improvement of the present utility model, described Current Feedback Control Circuit comprises U4B and R40, R42, and C22 delivers to the inverting input of power conditioning circuitry through R39, form feedback signal.

As a kind of improvement of the present utility model, described power conditioning circuitry comprises adjustable potentiometer W1 and Resistor-Capacitor Unit R35, R36, R38, C20, amplifier U4A. Q12, Q13, R48, R49, R50 forms mirror current source. According to the principle of current mirror symmetry, the output current of mirror current source is constantly equal to input current, and output loading changes does not affect output current, so claim again constant-current source, the input current of the R48 that flows through equates completely with the output current of the D25 that flows through. And the input current of current mirror is followed the variation of amplifier U4A output end voltage. Therefore, sample rate current PC amplifies through U4B positive, signal comparison with power conditioning circuitry, form feedback control signal, this signal is delivered to the input of mirror current source, the size of feedback signal directly changes the input current of mirror-image constant flow source, thereby the output current of mirror current source also changes thereupon.

As a kind of improvement of the present utility model, described frequency changer circuit comprises D25, U6, C46, R57, R58. Q2, Q14,36; C47, R51, the elements such as R52 form soft starting circuit jointly; R71, R74, C64 forms breaking circuit; abnormal letter is arranged to perfect safeguard measure, as over-and under-voltage, overcurrent; excess temperature, cooling fan damages etc., all can deliver to by relevant holding circuit the FLT end (pin 10) of master controller U6; realize protectiveness and stop, ensureing circuit safety work. This signal is also for remote auto control. U8 in full bridge driving circuit, U9 is high-speed MOSFET driver device, C76, C77; C80, C81 is filter capacitor, R80; R81 is input protection resistor, and D8 ~ D15 is clamp circuit, Z3; C86, R122 forms mu balanced circuit, C89; R101, C92, R103 is accelerating circuit; T2, T3 is two isolation drive transformers, adopts FERRITE CORE coiling to form.

With respect to prior art, advantage of the present utility model is as follows, 1) this technical scheme has solved closed-loop control, secondary high pressure sampling and a difficult problem of isolating, by repeatedly testing, can adopt the method for detection of primary electric current to realize closed-loop control, in the time of secondary load variation or power generating facilities and power grids fluctuation, feed back to frequency changer circuit by curent change, thereby change the operating frequency of MOS power device, make stable output; 2) when this technical scheme high-tension transformer input current changes, power output respective change, the input current of Correctly adjust transformer, power output is also adjusted thereupon; 3) this technical scheme is improved the stability of plasma-arc and reliability, uses the plasma apparatus of this high pressure plasma power supply composition, on probation by the scene that half a year is many, and any quality problems do not occur. Reliable product quality; 4) this technical scheme cost is lower, easy to utilize.

Brief description of the drawings

Fig. 1 is the utility model overall structure schematic diagram;

Fig. 2 is full-bridge circuit and current sampling circuit schematic diagram;

Fig. 3 is current feedback and VFC schematic diagram;

Fig. 4 is drive circuit schematic diagram.

Detailed description of the invention

In order to deepen understanding of the present utility model and understanding, below in conjunction with the drawings and specific embodiments, further illustrate the utility model.

Embodiment 1:

Referring to Fig. 1, a kind of high pressure plasma power supply, described plasma electrical source comprises rectification circuit, full-bridge circuit, D.C mutual-inductor, high-tension transformer, accessory power supply, frequency changer circuit, sample circuit, power conditioning circuitry and Current Feedback Control Circuit, described rectification circuit passes through full-bridge circuit, ac sensor connects high-tension transformer, described D.C mutual-inductor connects Current Feedback Control Circuit by sample circuit, described Current Feedback Control Circuit connects full-bridge circuit by frequency changer circuit, described power conditioning circuitry connects Current Feedback Control Circuit, described accessory power supply provides direct-current working volts for circuitry, referring to Fig. 2, full bridge soft switch circuit comprises full-bridge circuit, full bridge driving circuit, energy storage and filter capacitor, power valve protective circuit, block isolating circuit, wherein Q19 ~ Q22 forms full-bridge circuit, C70, and C71 is energy storage and filter capacitor, Z5 ~ Z8 and C50 ~ C53 forms power valve protective circuit, C37 ~ C40, C42 ~ C45, R54, R55 forms block isolating circuit, and circuit output connects high-tension transformer. referring to Fig. 4, full bridge driving circuit output G1 ~ G4Si road signal, driven MOS power tube Q19 ~ Q22 respectively, in described D.C mutual-inductor, CSP1 is that D.C mutual-inductor is elementary, and CPS1 is level, referring to Fig. 2, described sample circuit comprises full-wave rectifying circuit and filtering, nominal load circuit, wherein D26, and D27, D28, D29 forms full-wave rectifying circuit, C41, the filtering of R53 composition, nominal load circuit. their common composition current sampling circuits, when circuit working, current transformer, for the working alternating current on the former limit of high-tension transformer input of sampling, after over-sampling circuit, forms and changes corresponding current signal PC with the operating current of transformer primary side. sample rate current PC amplitude is less, through R44, and C33 elimination clutter, then deliver to amplifier U4B and R40, and R42, C22, amplifies little current signal. referring to Fig. 3, described Current Feedback Control Circuit comprises U4B and R40, R42, and C22 delivers to the inverting input of power conditioning circuitry through R39, form feedback signal, described power conditioning circuitry comprises adjustable potentiometer W1 and Resistor-Capacitor Unit R35, R36, and R38, C20, amplifier U4A etc. complete jointly. Q12, Q13, R48, R49, R50 forms mirror current source. according to the principle of current mirror symmetry, the output current of mirror current source is constantly equal to input current, and output loading changes does not affect output current, so claim again constant-current source, the input current of the R48 that flows through equates completely with the output current of the D25 that flows through. and the input current of current mirror is followed the variation of amplifier U4A output end voltage. therefore, sample rate current PC amplifies through U4B positive, with the signal comparison of power conditioning circuitry, forms feedback control signal, this signal is delivered to the input of mirror current source, the size of feedback signal directly changes the input current of mirror-image constant flow source, thereby the output current of mirror current source also changes thereupon, and described frequency changer circuit comprises D25, U6, C46, R57, R58, Q2, Q14,36, C47, R51, the elements such as R52 form soft starting circuit jointly, R71, R74, C64 forms breaking circuit, abnormal letter is arranged to perfect safeguard measure, as over-and under-voltage, overcurrent, excess temperature, cooling fan damages etc., all can deliver to by relevant holding circuit the FLT end (pin 10) of master controller U6, realize protectiveness and stop, ensureing circuit safety work. this signal is also for remote auto control. U8 in full bridge driving circuit, U9 is high-speed MOSFET driver device, C76, C77, C80, C81 is filter capacitor, R80, R81 is input protection resistor, and D8 ~ D15 is clamp circuit, Z3, C86, R122 forms mu balanced circuit, C89, R101, C92, R103 is accelerating circuit, T2, T3 is two isolation drive transformers, adopts FERRITE CORE coiling to form.

Operation principle: referring to Fig. 3, by conventional PWM controller U6 composition control and reponse system. When work, in the time that the working alternating current on the former limit of high-tension transformer input reduces, sample rate current PC also reduces, power conditioning circuitry U4A output voltage increases, image current reduces, curent change directly changes the charge constant of CT, and the slope of triangular wave is reduced, and the operating frequency of PWM controller U6 internal oscillator also reduces. The frequency of output OUTA and OUTB reduces thereupon. OUTA and OUTB deliver to the full bridge driving circuit shown in Fig. 4, full bridge driving circuit output G1 ~ G4 controls four MOS power device Q19 ~ Q22 ON times in full-bridge circuit (shown in Fig. 2) and becomes large, high-tension transformer operating frequency reduces, power output increases, input current increases thereupon, realizes Current Feedback Control. In like manner, in the time that the working alternating current on the former limit of high-tension transformer input increases, sample rate current PC also increases, power conditioning circuitry U4A output voltage reduces, image current increases, change the charge constant that directly changes CT, the slope of triangular wave is increased, the operating frequency of internal oscillator increases. The frequency of output OUTA and OUTB increases thereupon. OUTA and OUTB deliver to the full bridge driving circuit shown in Fig. 4, control four MOS power device Q19 ~ Q22 ON times in full-bridge circuit and reduce. High-tension transformer operating frequency increases, and power output reduces, and input current reduces thereupon. Therefore, the change of frequency of PWM controller U6 output OUTA and OUTB is relevant to the variation of power adjusting potentiometer and primary curent change. Potentiometer W1 is power manual setting value, primary electric current (sampled value PC) is value of feedback, as long as primary electric current changes, sampled value PC is after feedback, the frequency response of PWM controller changes, the operating frequency of full-bridge circuit is done corresponding variation thereupon, realizes current feedback closed-loop control.

It should be noted that; above-described embodiment is only preferred embodiment of the present utility model; be not used for limiting protection domain of the present utility model, being equal to of making on the basis of technique scheme replaced or substituted, and all belongs to protection domain of the present utility model.

Claims

1. a high pressure plasma power supply, it is characterized in that, described plasma electrical source comprises rectification circuit, full-bridge circuit, D.C mutual-inductor, high-tension transformer, accessory power supply, frequency changer circuit, sample circuit, power conditioning circuitry and Current Feedback Control Circuit, described rectification circuit passes through full-bridge circuit, ac sensor connects high-tension transformer, described D.C mutual-inductor connects Current Feedback Control Circuit by sample circuit, described Current Feedback Control Circuit connects full-bridge circuit by frequency changer circuit, described power conditioning circuitry connects Current Feedback Control Circuit, described accessory power supply is inverse-excitation type switch power-supply, for provide+12V of circuitry direct-current working volts.

2. high pressure plasma power supply according to claim 1; it is characterized in that; full bridge soft switch circuit comprises full-bridge circuit, full bridge driving circuit, energy storage and filter capacitor, power valve protective circuit, block isolating circuit; wherein triode Q19 ~ Q22 forms full-bridge circuit; capacitor C 70, C71 are energy storage and filter capacitor; impedance Z 5 ~ Z8, capacitor C 50 ~ C53 form power valve protective circuit; capacitor C 37 ~ C40, capacitor C 42 ~ C45 and resistance R 54, R55 form block isolating circuit, and circuit output connects high-tension transformer.

3. high pressure plasma power supply according to claim 1, is characterized in that, in described D.C mutual-inductor, CSP1 is that D.C mutual-inductor is elementary, and CPS1 is secondary.

4. according to the high pressure plasma power supply described in claim 2 or 3, it is characterized in that, described sample circuit comprises full-wave rectifying circuit and filtering, load circuit, wherein diode D26, D27, D28, D29 form full-wave rectifying circuit, and capacitor C 41, resistance R 53 form filtering, load circuit.

5. high pressure plasma power supply according to claim 4, is characterized in that, described power conditioning circuitry comprises adjustable potentiometer W1 and Resistor-Capacitor Unit R35, R36, R38, C20, amplifier U4A.

6. high pressure plasma power supply according to claim 5, is characterized in that, described frequency changer circuit comprises diode D25, integrated circuit U6, capacitor C 46, resistance R 57, R58.

7. high pressure plasma power supply according to claim 6, it is characterized in that, described Current Feedback Control Circuit comprises integrated circuit U4B and resistance R 40, and resistance R 42, capacitor C 22 are delivered to the inverting input of power conditioning circuitry through resistance R 39, forms feedback signal.