CN219918730U

CN219918730U - Main power circuit and intermediate frequency alternating current coating power supply

Info

Publication number: CN219918730U
Application number: CN202321474552.7U
Authority: CN
Inventors: 胡小龙
Original assignee: Suzhou Huichuan Control Technology Co Ltd
Current assignee: Suzhou Huichuan Control Technology Co Ltd
Priority date: 2023-06-09
Filing date: 2023-06-09
Publication date: 2023-10-27
Anticipated expiration: 2033-06-09

Abstract

The utility model discloses a main power circuit and an intermediate frequency alternating current coating power supply, which belong to the technical field of coating power supplies, wherein the main power circuit is respectively connected with a rectifying module, an inversion module and a transformation module; the rectification module comprises a three-phase controllable rectification circuit; the detection module detects inductance current in the three-phase controllable rectifying circuit, bus voltage output by the three-phase controllable rectifying circuit and output voltage of the transformation module; the control module generates a first adjusting signal according to the inductance current and the bus voltage to realize the adjustment of the bus voltage, and generates a second adjusting signal according to the bus voltage and the output voltage to realize the adjustment of the duty ratio of the positive and negative pulse square wave signals output by the inversion module. The utility model solves the problems that more load impedance cannot be matched and the output quality is difficult to ensure in the prior art, achieves the effect of realizing stable output of the power supply and ensuring the matching of the output voltage and different load impedance.

Description

Main power circuit and intermediate frequency alternating current coating power supply

Technical Field

The utility model relates to the technical field of coating power supplies, in particular to a main power circuit and an intermediate frequency alternating current coating power supply.

Background

The ion plating technology is closely related to the development of human society, and the film products prepared by the plasma enhancement technology relate to various fields of televisions, mobile phones, semiconductors, optoelectronic devices, energy utilization, surface hardening of materials, wear resistance, corrosion resistance, oxidation resistance and the like.

At present, most of alternating current coating power supplies used in the ion coating technology have the problem that wider load impedance cannot be matched. Meanwhile, when the output voltage level of the intermediate frequency alternating current coating power supply is lower, the duty ratio of the inversion module needs to be adjusted to be smaller, so that the output quality of the power supply is relatively reduced.

Therefore, the existing medium-frequency alternating-current coating power supply has the problem that more load impedance cannot be matched, and the output quality is difficult to ensure.

Disclosure of Invention

The main purpose of the utility model is that: the main power circuit and the intermediate frequency alternating current coating power supply are provided, and the technical problems that more load impedance cannot be matched and the output quality is difficult to ensure in the prior art are solved.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

in a first aspect, the utility model provides a main power circuit, which comprises a rectifying module, an inversion module, a resonance module, a transformation module, a detection module and a control module, wherein the rectifying module, the inversion module, the resonance module and the transformation module are sequentially connected;

The rectification module comprises a three-phase controllable rectification circuit;

the detection module is used for detecting the inductance current in the three-phase controllable rectifying circuit, the bus voltage output by the three-phase controllable rectifying circuit and the output voltage of the transformation module;

the control module is used for generating a first regulating signal according to the inductance current and the bus voltage, generating a second regulating signal according to the bus voltage and the output voltage, and outputting the first regulating signal and the second regulating signal;

the detection module is further used for forwarding the first adjusting signal to the rectification module to adjust the bus voltage, forwarding the second adjusting signal to the inversion module to adjust the duty ratio of the positive and negative pulse square wave signals output by the inversion module.

Optionally, in the main power circuit, the method further includes:

the auxiliary power module is respectively connected with the power supply, the detection module and the control module and is used for converting alternating current provided by the power supply and supplying power to the detection module and the control module.

Optionally, in the above main power circuit, the detection module includes:

The first detection unit is respectively connected with the control module and the three-phase inductor of the three-phase controllable rectifying circuit and is used for detecting the current of the three-phase inductor to obtain the inductor current;

the second detection unit is respectively connected with the control module and the positive output end and the negative output end of the three-phase controllable rectifying circuit and is used for detecting the voltage between the positive bus and the negative bus to obtain the bus voltage;

and the third detection unit is respectively connected with the control module and the positive output end and the negative output end of the transformer in the transformation module and is used for detecting the voltage between the positive output line and the negative output line to obtain the output voltage.

Optionally, in the main power circuit, the inverter module includes a full-bridge inverter circuit;

the detection module further comprises:

the first driving unit is respectively connected with the control module and three bridge arms of the three-phase controllable rectifying circuit and is used for controlling the on-off of switching tubes in the three bridge arms according to a first adjusting signal output by the control module;

and the second driving unit is respectively connected with the control module and two bridge arms of the full-bridge inverter circuit and is used for controlling the on-off of switching tubes in the two bridge arms according to a second adjusting signal output by the control module.

Optionally, in the main power circuit, the three-phase controllable rectifying circuit includes an inductance La, an inductance Lb, an inductance Lc, a switching tube Q1, a switching tube Q2, a switching tube Q3, a switching tube Q4, a switching tube Q5, and a switching tube Q6;

one end of the inductor La is connected with a first phase of alternating current, one end of the inductor Lb is connected with a second phase of alternating current, one end of the inductor Lc is connected with a third phase of alternating current, the other end of the inductor La is connected with a source electrode of the switching tube Q1 and a drain electrode of the switching tube Q4, the other end of the inductor Lb is connected with a source electrode of the switching tube Q2 and a drain electrode of the switching tube Q5, the other end of the inductor Lc is connected with a source electrode of the switching tube Q3 and a drain electrode of the switching tube Q6, the drain electrode of the switching tube Q1, the drain electrode of the switching tube Q2 and the drain electrode of the switching tube Q3 are all connected with a positive input end of the full-bridge inverter circuit, the source electrode of the switching tube Q4, the source electrode of the switching tube Q5 and the source electrode of the switching tube Q6 are all connected with a negative input end of the full-bridge inverter circuit, and the gate electrode of the switching tube Q1, the gate electrode of the switching tube Q2, the gate electrode of the switching tube Q3, the gate electrode of the switching tube Q4 and the driving unit Q6 are all connected with the gate electrode of the switching tube Q6.

Optionally, in the main power circuit, the full-bridge inverter circuit includes a switching tube Q7, a switching tube Q8, a switching tube Q9, and a switching tube Q10;

the drain electrode of the switch tube Q7 and the drain electrode of the switch tube Q8 are connected with the positive output end of the rectifying module, the source electrode of the switch tube Q9 and the source electrode of the switch tube Q10 are connected with the negative output end of the rectifying module, the source electrode of the switch tube Q7 and the drain electrode of the switch tube Q9 are connected with the positive input end of the resonant module, the source electrode of the switch tube Q8 and the drain electrode of the switch tube Q10 are connected with the negative input end of the resonant module, and the grid electrode of the switch tube Q7, the grid electrode of the switch tube Q8, the grid electrode of the switch tube Q9 and the grid electrode of the switch tube Q10 are connected with the second driving unit.

Optionally, in the main power circuit, the resonance module includes a first filter circuit, a second filter circuit, and a third filter circuit;

the input end of the first filter circuit is connected with the inversion module, the output end of the first filter circuit is connected with the input end of the second filter circuit, the output end of the second filter circuit is respectively connected with the positive input end of the transformation module and the input end of the third filter circuit, and the output end of the third filter circuit is connected with the negative input end of the transformation module;

The inversion module is used for inverting the direct current into positive and negative pulse square wave signals with adjustable duty ratio, and the resonance module is used for performing three-stage resonance filtering on the positive and negative pulse square wave signals to obtain sine wave signals.

Optionally, in the main power circuit, the first filter circuit includes an inductor L1 and a capacitor C1, the second filter circuit includes a capacitor C2 and an inductor L2, and the third filter circuit includes a capacitor C3 and an inductor L3;

one end of the inductor L1 is connected with the positive output end of the inversion module, the other end of the inductor L1 is connected with the positive input end of the second filter circuit, one end of the capacitor C1 is connected with the negative output end of the inversion module, and the other end of the capacitor C1 is connected with the negative input end of the second filter circuit;

one end of the capacitor C2 and one end of the inductor L2 are connected with the positive output end of the first filter circuit and the positive input end of the transformation module; the other end of the capacitor C2 and the other end of the inductor L2 are connected with the negative output end of the first filter circuit and the input end of the third filter circuit;

one end of the capacitor C3 is connected with the negative output end of the second filter circuit, the other end of the capacitor C3 is connected with one end of the inductor L3, and the other end of the inductor L3 is connected with the negative input end of the transformation module.

Optionally, in the main power circuit, the transformation module includes a transformer T1;

the positive input end of the transformer T1 is connected with the positive output end of the second filter circuit, the negative input end of the transformer T1 is connected with the output end of the third filter circuit, the positive output end of the transformer T1 is connected with the positive electrode of the load, and the negative output end of the transformer T1 is connected with the negative electrode of the load.

In a second aspect, the utility model further provides an intermediate frequency alternating current coating power supply, which comprises the main power circuit.

The one or more technical schemes provided by the utility model can have the following advantages or at least realize the following technical effects:

according to the main power circuit and the intermediate frequency alternating current coating power supply, the detection module is additionally arranged in the main power circuit, the inductance current in the three-phase controllable rectifying circuit in the rectifying module, the bus voltage output by the three-phase controllable rectifying circuit and the output voltage of the transformation module are detected, the control module generates a first regulating signal according to the inductance current and the bus voltage, and generates a second regulating signal according to the bus voltage and the output voltage, the detection module forwards the first regulating signal and the second regulating signal, so that the three-phase controllable rectifying circuit receives the first regulating signal, the bus voltage output by closed-loop regulation, the inversion module receives the second regulating signal, the duty ratio of the positive and negative pulse square wave signals output by the inversion module is regulated, closed-loop regulation of the output voltage is realized by regulating the duty ratio of the positive and negative pulse square wave signals output by the bus voltage and the inversion module, and high output voltage quality can be still ensured under different output voltage grades, stable output of the power supply can be realized, the output voltage and different load impedance matching can be ensured, and the power supply can meet various load impedance conditions and meet more practical application scenes.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a first embodiment of a main power circuit according to the present utility model;

FIG. 2 is a schematic diagram of a connection of a second embodiment of the main power circuit of the present utility model;

FIG. 3 is a circuit topology of a three-phase controllable rectifying circuit according to a second embodiment of the main power circuit of the present utility model;

fig. 4 is a circuit topology diagram of a full-bridge inverter circuit in a second embodiment of the main power circuit of the present utility model;

fig. 5 is a circuit topology diagram of a resonance module and a transformation module in a second embodiment of the main power circuit of the present utility model.

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present utility model more apparent, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that, in the present utility model, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a device or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such device or system. Without further limitation, an element defined by the phrase "comprising … …" does not exclude that an additional identical element is present in a device or system comprising the element. In the present utility model, unless explicitly specified and limited otherwise, the terms "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be either a fixed connection or a removable connection or integrated; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium; the communication between the two elements can be realized, or the interaction relationship between the two elements can be realized. In the present utility model, if there is a description referring to "first", "second", etc., the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the present utility model, suffixes such as "module", "part" or "unit" used for representing elements are used only for facilitating the description of the present utility model, and have no specific meaning per se. Thus, "module," "component," or "unit" may be used in combination. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

Analysis of the prior art shows that in the alternating current coating power supply used by the ion coating technology, the system power flow direction of the medium-frequency alternating current coating power supply is as follows: the alternating current is converted into direct current through the rectifying module, the direct current is converted into positive and negative pulse square wave signals with adjustable duty ratio through the inverting module, the positive and negative pulse square wave signals are filtered into sine wave signals through the resonance module, and finally the sine wave signals are output through the transformer.

At present, most of medium-frequency alternating-current coating power supplies adopt three-phase uncontrolled rectification for the rectifying modules, the three-phase uncontrolled rectification technology is adopted, the busbar voltage is not adjustable, and at most, the output of different voltage grades can be realized only by adjusting the inversion module, so that the problem that the medium-frequency alternating-current coating power supply cannot be matched with wider load impedance exists. Meanwhile, when the output voltage level of the intermediate frequency alternating current coating power supply is lower, the duty ratio of the inversion module needs to be adjusted to be smaller, so that the output quality of the power supply is relatively reduced.

In order to improve the output quality of the power supply when outputting different voltage classes, some intermediate frequency alternating current coating power supplies realize the matching of more load impedance by adjusting the turn ratio of the transformer, but the mode needs a complex transformer, increases certain design difficulty and is not suitable for practical application.

In view of the technical problems that more load impedance cannot be matched and the output quality is difficult to ensure in the prior art, the utility model provides a main power circuit and an intermediate frequency alternating current coating power supply, and specific embodiments and implementation modes are as follows:

example 1

Referring to fig. 1, fig. 1 is a schematic connection diagram of a first embodiment of a main power circuit according to the present utility model; the embodiment provides a main power circuit which can be applied to an intermediate frequency alternating current coating power supply. The main power circuit may include:

the device comprises a rectifying module, an inversion module, a resonance module and a transformation module which are connected in sequence;

the detection module is respectively connected with the rectification module, the inversion module and the transformation module, and the control module is connected with the detection module;

Specifically, the rectification module adopts a three-phase controllable rectification circuit, three bridge arms of the three-phase controllable rectification circuit can be correspondingly connected with three-phase alternating current through an inductor respectively, and the upper bridge arm and the lower bridge arm of each bridge arm adopt controllable switching tubes; the three-phase controllable rectifying circuit is used for converting alternating current into direct current, the direct current is connected into the inversion module through the positive bus and the negative bus, and the controllable switching tube is used for being conducted or turned off according to the received adjusting signal, so that the adjustment control of the three-phase current of the alternating current is realized, and the voltage between the positive bus and the negative bus is adjusted.

The three-phase non-control rectification method is different from the existing three-phase non-control rectification method, the rectification module can realize closed-loop adjustment of bus voltage, so that the follow-up adjustment of the duty ratio of positive and negative pulse square wave signals output by the inversion module can be continuously realized based on the adjustable bus voltage, and the closed-loop adjustment of output voltage can be realized.

The detection module is used as an intermediate medium for detecting the voltage or current of the rectifier module, the resonance module and other power modules during operation, and simultaneously transmits the control signals output by the control module to the rectifier module and the inversion module, and finally, the power supply output of different voltage grades is realized through the on-off control of the switching tube in the power module.

The rectification module and the inversion module can be adjusted to ensure certain output voltage quality and match more load impedance conditions on the premise of different output voltage grades.

In a specific embodiment, as shown in fig. 1, the rectifying module may be connected to a power supply, to convert ac provided by the power supply into dc, where the power supply may be a power grid or a power supply device that provides three-phase ac, the rectifying module specifically converts the three-phase ac into two-phase dc, the inverting module may invert the dc into a positive and negative pulse square wave signal with an adjustable duty ratio, specifically converts the two-phase dc into two-phase ac, the resonant module may perform resonance filtering on the positive and negative pulse square wave signal to obtain a sine wave signal, and the transforming module performs transformation processing on the sine wave signal to obtain an output voltage, where the output voltage may supply power to a load, and the load may be a plasma load.

In the process, the detection module can detect the inductance current in the three-phase controllable rectifying circuit, the bus voltage output by the three-phase controllable rectifying circuit and the output voltage of the transformation module, then the detected inductance current, bus voltage and output voltage are input to the control module, the control module generates a first adjusting signal according to the inductance current and the bus voltage, the first adjusting signal is forwarded to the rectifying module through the detection module, and can be specifically sent to the controllable switching tubes of three bridge arms of the three-phase controllable rectifying circuit to realize the adjustment of the output bus voltage, meanwhile, the control module also generates a second adjusting signal according to the bus voltage and the output voltage, and the second adjusting signal is forwarded to the inversion module through the detection module to realize the duty ratio adjustment of the positive and negative pulse square wave signals output by the inversion module, so that the adjustment of the final output voltage of the transformation module is realized.

The main power circuit is applied to an alternating current coating power supply, is used as an alternating current coating power supply with sinusoidal output and supplies power for a plasma load, and the coating power supply can effectively filter an alternating current square wave signal into a sinusoidal wave signal so as to ensure the sine degree of output voltage; the rectification module can be controlled according to the detected inductance current and the bus voltage in time, so that the output bus voltage is regulated, the inversion module is controlled based on the detected bus voltage and the output voltage, the duty ratio of the output positive and negative pulse square wave signals is regulated, the closed-loop regulation of the output voltage of the transformation module is realized based on the regulation of the bus voltage and the regulation of the duty ratio of the positive and negative pulse square wave signals, the quality of the output voltage is ensured while different voltage classes are met, and more load impedance matching can be realized.

According to the main power circuit, the detection module is additionally arranged in the main power circuit, the inductance current in the three-phase controllable rectifying circuit in the rectifying module, the bus voltage output by the three-phase controllable rectifying circuit and the output voltage of the voltage transformation module are detected, the control module generates a first regulating signal according to the inductance current and the bus voltage, and generates a second regulating signal according to the bus voltage and the output voltage, the detection module is used for transmitting the first regulating signal and the second regulating signal, the three-phase controllable rectifying circuit receives the first regulating signal, the bus voltage is subjected to closed-loop regulation and the inversion module is used for receiving the second regulating signal, the duty ratio of the positive and negative pulse square wave signals output by the inversion module is regulated, the closed-loop regulation of the output voltage is realized by regulating the duty ratio of the positive and negative pulse square wave signals output by the bus voltage and the inversion module, the quality of the higher output voltage can be still ensured under different output voltage grades, the stable output of the power supply can be realized, the output voltage and the impedance matching of different loads can be ensured, and the power supply can meet various load impedance conditions and more practical application scenes can be met.

Example two

Referring to fig. 2, fig. 2 is a schematic diagram of a second embodiment of a main power circuit according to the present utility model; on the basis of the first embodiment, the present embodiment further proposes a main power circuit applicable to an intermediate frequency ac coating power supply.

Further, the main power circuit may further include:

Specifically, the auxiliary power module converts alternating current provided by the power supply into working voltage required by the work of the detection module and the control module, and supplies power for the detection module and the control module. Alternatively, the auxiliary power module may be an independent external power device for supplying power to the detection module and the control module.

Further, the detection module may include:

Still further, the inverter module may include a full bridge inverter circuit;

the detection module may further include:

Specifically, the inversion module comprises a full-bridge inversion circuit, and a switching tube in the full-bridge inversion circuit can also adopt a controllable switching tube for being switched on or off according to the received adjusting signal, so that the positive and negative pulse square wave signal duty ratio output by the inversion module is adjusted.

In a specific embodiment, the control module can specifically send the second regulating signal generated according to the bus voltage and the output voltage to the controllable switch tube of the full-bridge inverter circuit when forwarding the second regulating signal to the inverter module through the detection module.

In one embodiment, in the rectifying module, a three-phase controllable rectifying circuit may specifically be a three-phase active PFC (Power Factor Correction ) circuit, where the three-phase active PFC circuit is a three-phase PWM rectifying circuit formed by six switching tubes, and the bus voltage may be adjusted by controlling the on/off states of the six switching tubes. The three-phase active PFC circuit can improve the power factor and the efficiency of the rectifying module.

As shown in the circuit topology diagram of fig. 3, the three-phase controllable rectifying circuit may include an inductance La, an inductance Lb, an inductance Lc, a switching tube Q1, a switching tube Q2, a switching tube Q3, a switching tube Q4, a switching tube Q5, and a switching tube Q6;

Specifically, one end of the inductor La is connected to R, one end of the inductor Lb is connected to S, one end of the inductor Lc is connected to T, a connection point of the drain of the switching tube Q1, the drain of the switching tube Q2, and the drain of the switching tube Q3 is used as a positive output terminal dc+ of the rectifying module, connected to a positive input terminal of the inverting module, and a connection point of the source of the switching tube Q4, the source of the switching tube Q5, and the source of the switching tube Q6 is used as a negative output terminal DC-of the rectifying module, connected to a negative input terminal of the inverting module. The switching tube Q1 and the switching tube Q4 form a first bridge arm of the three-phase controllable rectifying circuit, the switching tube Q1 is an upper bridge arm of the first bridge arm, the switching tube Q4 is a lower bridge arm of the first bridge arm, the switching tube Q2 and the switching tube Q5 form a second bridge arm of the three-phase controllable rectifying circuit, the switching tube Q2 is an upper bridge arm of the second bridge arm, the switching tube Q5 is a lower bridge arm of the second bridge arm, the switching tube Q3 and the switching tube Q6 form a third bridge arm of the three-phase controllable rectifying circuit, the switching tube Q3 is an upper bridge arm of the third bridge arm, and the switching tube Q6 is a lower bridge arm of the third bridge arm. The first bridge arm is connected with R of alternating current through an inductor La, the second bridge arm is connected with S of alternating current through an inductor Lb, and the third bridge arm is connected with T of alternating current through an inductor Lc

The on-off control of the six switching tubes is realized by respectively received regulating signals, for example, the first regulating signals output by the control module, and three-phase alternating current is converted into two-phase direct current and output through the on-off switching of the six switching tubes. The switching transistors Q1, Q2, Q3, Q4, Q5 and Q6 may be controllable switching transistors such as metal oxide semiconductor field effect transistors (MOS transistors) or insulated gate bipolar transistors (IGBT transistors). The MOS tube and the IGBT tube can be used as power switch tubes to realize power switching control.

In this embodiment, each bridge arm of the three-phase active PFC circuit is composed of an upper switch tube and a lower switch tube, and the control of phase current is achieved by controlling the on-off of the two switch tubes of a single bridge arm. For example, when the current Ia of the inductor La > 0, the switching tube Q4 is closed, the R-phase inductor current will increase, the switching tube Q4 is opened, the inductor La freewheels through the parasitic diode of the switching tube Q1, and the R-phase inductor current will decrease; when the current Ia of the inductor La is smaller than 0, the R-phase inductor current is increased when the switch tube Q1 is closed, the switch tube Q1 is opened, the inductor La freewheels through the parasitic diode of the switch tube Q4, and the R-phase inductor current is reduced. Therefore, the control of the phase current can be realized by controlling the on-off of the upper switch tube and the lower switch tube of the bridge arm, and finally the adjustment and the control of the bus voltage are realized. Meanwhile, as the sum of three-phase currents is zero, only the upper and lower tubes of two bridge arms are controlled, so that the control difficulty can be reduced, and the switching loss is reduced. Compared with a three-phase uncontrolled rectifying circuit, the three-phase active PFC circuit adopted in the embodiment not only improves the power factor and efficiency of the power supply, but also enables the power supply to be suitable for high-power occasions.

In this embodiment, the first detection unit of the detection module may be respectively connected to the control module, the other end of the inductor La, the other end of the inductor Lb, and the other end of the inductor Lc, and configured to detect currents of the inductor La, the inductor Lb, and the inductor Lc, that is, three-phase inductors, to obtain three inductance currents, and output the three inductance currents to the control module; the second detection unit of the detection module can be respectively connected with the control module, the positive output end DC+ of the rectification module and the negative output end DC-of the rectification module, and is used for detecting the voltage between the positive bus and the negative bus, namely DC+ and DC-, so as to obtain bus voltage, and outputting the bus voltage to the control module, so that the control module generates a first regulating signal according to the inductance current and the bus voltage; meanwhile, the first driving unit of the detection module can be respectively connected with the control module, the grid electrode of the switching tube Q1, the grid electrode of the switching tube Q2, the grid electrode of the switching tube Q3, the grid electrode of the switching tube Q4, the grid electrode of the switching tube Q5 and the grid electrode of the switching tube Q6, and is used for controlling the on-off of each switching tube according to the first adjusting signal output by the control module.

Further, as shown in the circuit topology diagram of fig. 4, in the inverter module, the full-bridge inverter circuit may include a switching tube Q7, a switching tube Q8, a switching tube Q9, and a switching tube Q10;

Specifically, the drain electrode of the switching tube Q7 and the drain electrode of the switching tube Q8 are both connected with the positive output end dc+ of the rectifying module, the source electrode of the switching tube Q9 and the source electrode of the switching tube Q10 are both connected with the negative output end DC-of the rectifying module, the connection point of the source electrode of the switching tube Q7 and the drain electrode of the switching tube Q9 is used as the positive output end ac+ of the inverting module and is connected with the positive input end of the resonating module, and the connection point of the source electrode of the switching tube Q8 and the drain electrode of the switching tube Q10 is used as the negative output end AC-of the inverting module and is connected with the negative input end of the resonating module. The switching tube Q7 and the switching tube Q9 form a first bridge arm of the full-bridge inverter circuit, and the switching tube Q8 and the switching tube Q10 form a second bridge arm of the full-bridge inverter circuit.

The on-off control of the four switching tubes is realized by respectively received regulating signals, for example, the on-off control of the four switching tubes is realized by a second regulating signal output by a control module, the on-off switching of the four switching tubes is used for converting the biphase direct current into biphase alternating current, and alternating current square wave signals with symmetrical positive and negative pulses, namely the positive and negative pulse square wave signals with adjustable duty ratio, are output. The switching transistor Q7, the switching transistor Q8, the switching transistor Q9, and the switching transistor Q10 may be controllable switching transistors such as metal oxide semiconductor field effect transistors (MOS transistors) or insulated gate bipolar transistors (IGBT transistors). The MOS tube and the IGBT tube can be used as power switch tubes to realize power switching control.

The inversion module adopts a full-bridge inversion circuit, wherein the pair of tubes of two bridge arms are simultaneously turned on, namely, the switching tube Q7 and the switching tube Q10 are simultaneously turned on, or the switching tube Q8 and the switching tube Q9 are simultaneously turned on, and the positive and negative pulse square wave signals with different duty ratios are output by controlling the on-off of the two pairs of switching tubes.

In this embodiment, the second driving unit of the detection module may be connected to the control module, the gate of the switching tube Q7, the gate of the switching tube Q8, the gate of the switching tube Q9, and the gate of the switching tube Q10, respectively, for controlling on/off of each switching tube according to the second adjustment signal output by the control module.

In one embodiment, as shown in the circuit topology diagram of fig. 5, the resonance module may include a first filter circuit, a second filter circuit, and a third filter circuit;

the inversion module is used for inverting the received direct current into positive and negative pulse square wave signals with adjustable duty ratio, and the resonance module is used for performing three-stage resonance filtering on the positive and negative pulse square wave signals to obtain sine wave signals.

Specifically, as shown in fig. 5, the positive input end of the first filter circuit is connected with the positive output end ac+ of the inversion module, the negative input end is connected with the negative output end AC-of the inversion module, the positive output end and the negative output end of the first filter circuit are correspondingly connected with the positive input end and the negative input end of the second filter circuit, the positive output end of the second filter circuit is connected with the positive input end of the transformation module, the negative output end is connected with the input end of the third filter circuit, and the output end of the third filter circuit is connected with the negative input end of the transformation module. The second filter circuit is a parallel resonant circuit, and the third filter circuit is a series resonant circuit.

In a specific implementation, the resonant frequency f of the resonant module _R Can be set to a switching frequency f with the inverter module _s In agreement, i.e

Where L represents the effective inductance of the resonant module and C represents the effective capacitance of the resonant module.

The resonance module adopts a three-stage resonance filter circuit, and the three-stage resonance filter circuit sequentially passes through a first filter circuit, a second filter circuit and a third filter circuit to carry out three-time filter treatment, so that positive and negative pulse square wave signals are effectively filtered, ripple waves and noise of the voltage are weakened to a greater extent, an output sine wave signal has a very low THD (Total Harmonic Distortion ) value, and the sine degree of an output waveform is ensured.

The three-level resonance mode is adopted to filter the square wave signal into the sine wave signal, when the plasma load generates an arc, the softness of the sine wave signal waveform and the resonance inductance contained in the three-level resonance mode can effectively inhibit the load from generating a current arc, and the number of the arcs generated in unit time is improved.

Further, as shown in fig. 5, in the resonant module, the first filter circuit may include an inductance L1 and a capacitance C1, the second filter circuit includes a capacitance C2 and an inductance L2, and the third filter circuit includes a capacitance C3 and an inductance L3;

One end of an inductor L1 is connected with a positive output end AC+ of the inversion module, the other end of the inductor L1 is connected with a positive input end of the second filter circuit, one end of a capacitor C1 is connected with a negative output end AC-of the inversion module, and the other end of the capacitor C1 is connected with a negative input end of the second filter circuit;

one end of a capacitor C3 is connected with the negative output end of the second filter circuit, the other end of the capacitor C3 is connected with one end of an inductor L3, and the other end of the inductor L3 is connected with the negative input end of the voltage transformation module.

The second filter circuit is a parallel resonant circuit, wherein the capacitor C2 is a parallel resonant capacitor, and the inductor L2 is a parallel resonant inductor. The third filter circuit is a series resonant circuit, wherein the capacitor C3 is a series resonant capacitor, and the inductor L3 is a series resonant inductor.

Further, as shown in fig. 5, the transformation module may include a transformer T1;

the positive input end of the transformer T1 is connected with the positive output end of the second filter circuit, the negative input end of the transformer T1 is connected with the output end of the third filter circuit, the positive output end Vout+ of the transformer T1 is connected with the positive electrode of the load, and the negative output end Vout-of the transformer T1 is connected with the negative electrode of the load.

The positive output end Vout+ of the transformer T1 is the positive output end of the intermediate frequency alternating current coating power supply where the main power circuit is located, and the negative output end Vout-of the transformer T1 is the negative output end of the intermediate frequency alternating current coating power supply where the main power circuit is located.

The sine wave signal output by the resonance module is connected to a load end through the boosting of the transformer T1, and the transformer T1 has the function of realizing output boosting on one hand and realizing load impedance matching on the other hand.

In this embodiment, the third detecting unit may be connected to the control module, the positive output terminal vout+ and the negative output terminal Vout-of the transformer T1, respectively, and configured to detect voltages between the positive output line and the negative output line, that is, vout+ and Vout-, to obtain an output voltage, and output the output voltage to the control module, so that the control module generates the second regulation signal according to the bus voltage and the output voltage.

According to the main power circuit, the output voltage quality of the intermediate frequency alternating current coating power supply is improved from the angle of a power topological structure, and on-off of switching tubes in the rectifying module and the inverting module can be adjusted, so that the output voltage quality is guaranteed to a certain extent on the premise of different voltage grades, and more load impedance conditions can be matched. And the resonance module adopts a three-stage resonance mode, positive and negative pulse square wave signals are filtered into sine wave signals, when an arc occurs to a plasma load, the softness of the sine wave signal waveform and the resonance inductance contained in the three-stage resonance mode can effectively inhibit the load from generating current arcs, and the number of the arcs occurring in unit time is improved.

Example III

The present embodiment provides an intermediate frequency ac plating power supply, which may include the main power circuit of the first embodiment or the second embodiment.

The medium-frequency alternating-current coating power supply can supply power to a plasma load and output sine wave output voltage, can effectively inhibit arc energy and reduces damage to the surface of a workpiece.

The specific structure of the main power circuit refers to the above embodiments, and since the present embodiment adopts all the technical solutions of all the embodiments, at least the technical solutions of the embodiments have all the beneficial effects brought by the technical solutions of the embodiments, which are not described in detail herein.

It should be noted that, the foregoing reference numerals of the embodiments of the present utility model are merely for describing the embodiments, and do not represent the advantages and disadvantages of the embodiments. The foregoing description is only of the optional embodiments of the present utility model, and is not intended to limit the scope of the utility model, and all equivalent structural changes made by the description of the present utility model and the accompanying drawings under the concept of the present utility model, or direct or indirect application in other related technical fields, are included in the scope of the present utility model.

Claims

1. The main power circuit comprises a rectifying module, an inversion module, a resonance module and a transformation module which are sequentially connected, and is characterized by further comprising a detection module which is respectively connected with the rectifying module, the inversion module and the transformation module, and a control module which is connected with the detection module;

2. The main power circuit of claim 1, further comprising:

3. The main power circuit of claim 1, wherein the detection module comprises:

4. The main power circuit of claim 3, wherein the inverter module comprises a full-bridge inverter circuit;

the detection module further comprises:

5. The main power circuit of claim 4, wherein the three-phase controllable rectifying circuit comprises an inductance La, an inductance Lb, an inductance Lc, a switching tube Q1, a switching tube Q2, a switching tube Q3, a switching tube Q4, a switching tube Q5, and a switching tube Q6;

6. The main power circuit of claim 4, wherein the full-bridge inverter circuit comprises a switching tube Q7, a switching tube Q8, a switching tube Q9, and a switching tube Q10;

7. The main power circuit of claim 1, wherein the resonant module comprises a first filter circuit, a second filter circuit, and a third filter circuit;

8. The main power circuit of claim 7, wherein the first filter circuit comprises an inductance L1 and a capacitance C1, the second filter circuit comprises a capacitance C2 and an inductance L2, and the third filter circuit comprises a capacitance C3 and an inductance L3;

9. The main power circuit of claim 7, wherein the transformation module comprises a transformer T1;

10. An intermediate frequency ac coating power supply comprising a main power circuit as claimed in any one of claims 1 to 9.