CN213637502U

CN213637502U - Welding power supply circuit, welding power supply device and electric welding machine

Info

Publication number: CN213637502U
Application number: CN202022318250.3U
Authority: CN
Inventors: 郑兵; 江凡; 菊红军
Original assignee: Shenzhen Adax Technology Co ltd
Current assignee: Shenzhen Adax Technology Co ltd
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2021-07-06
Anticipated expiration: 2030-10-16

Abstract

The utility model belongs to the technical field of the power, a welding power supply circuit, welding power supply unit and electric welding are provided, according to through first gate pole drive module first gate pole drive signal is generated to first original drive signal, and second gate pole drive module basis second original drive signal generates second gate pole drive signal, first gate pole drive signal with second gate pole drive signal drive first power tube switch module with second power tube switch module switches on in turn to it is right through rectification and afterflow module the voltage signal of transformer module output carries out rectification and afterflow and handles to realize carrying out the purpose of adjusting to welding source open-circuit voltage, solve the open-circuit voltage of current welding source and can not adjust by far, or just can adjust but the adjustment range is little for a short time, the relatively poor problem of welding process adaptability.

Description

Welding power supply circuit, welding power supply device and electric welding machine

Technical Field

The application belongs to the technical field of power supplies, and particularly relates to a welding power supply circuit, a welding power supply device and an electric welding machine.

Background

The output voltage of the welding power supply is divided into a circuit voltage and a working voltage, wherein the open circuit voltage refers to the output voltage measured when the power output end is not connected with any load under the condition of electrifying, namely the voltage when the welding power supply does not work, and the voltage is generally between 50V and 90V; the operating voltage is the voltage at which normal welding occurs after ignition of the arc, and is typically around 30V.

In order to meet the arc starting requirement during welding, the open circuit voltage of a welding power supply is generally designed to be much higher than the working voltage, but the higher open circuit voltage cannot meet the requirements of various safety regulations and different welding process procedures on the output voltage, so that the output open circuit voltage of the welding power supply needs to be adjusted.

SUMMERY OF THE UTILITY MODEL

The application aims to provide a welding power supply circuit, a welding power supply device and an electric welding machine, and aims to solve the problems that an existing welding power supply is small in open-circuit voltage adjusting range and poor in welding process adaptability.

A first aspect of an embodiment of the present application provides a welding power supply circuit, including:

the current input end of the first power tube switch module is connected with the positive polarity end of the direct current bus;

the first end of the primary winding of the transformer module is connected with the current output end of the first power tube switch module;

a current input end of the second power tube switch module is connected with a second end of the primary winding of the transformer module, and a current output end of the second power tube switch module is connected with a negative polarity end of the direct current bus;

the first gate driving module is used for receiving a first original driving signal and generating a first gate driving signal according to the first original driving signal;

the second gate driving module is used for receiving a second original driving signal and generating a second gate driving signal according to the second original driving signal; the first gate driving signal and the second gate driving signal drive the first power tube switch module and the second power tube switch module to be alternatively conducted;

and the rectification and follow current module is connected with the secondary winding of the transformer module and is used for rectifying and follow current of the voltage signal output by the transformer module.

In one embodiment, the welding power supply circuit further comprises:

and the voltage regulating module is connected with the rectifying and follow current module and is used for regulating the open-circuit voltage output by the rectifying and follow current module according to the input voltage control signal.

In one embodiment, the welding power supply circuit further comprises:

and the auxiliary voltage reduction module is connected with the rectification and follow current module and is used for outputting an auxiliary voltage source according to an input auxiliary power supply control signal.

In one embodiment, the first gate drive module comprises: the circuit comprises a first resistor, a second resistor, a first voltage regulator tube and a first capacitor;

the first end of the first resistor is connected with the positive polarity end of a first original driving signal source, the second end of the first resistor and the first end of the second resistor are connected with the control end of the first power tube circuit in a sharing mode, the second end of the second resistor, the anode of the first voltage-regulator tube and the first end of the first capacitor are connected with the negative polarity end of the first original driving signal source in a sharing mode, and the cathode of the first voltage-regulator tube and the second end of the first capacitor are connected with the first end of a primary winding of the transformer module in a sharing mode;

the second gate driving module includes: the first resistor, the second resistor, the third capacitor and the fourth capacitor are connected in series;

the first end of the third resistor is connected with the positive polarity end of a second original driving signal source, the second end of the third resistor and the first end of the fourth resistor are connected to the control end of the second power tube module in a shared mode, the second end of the fourth resistor, the first end of the second capacitor and the anode of the second voltage regulator tube are connected to the negative polarity end of the second original driving signal source in a shared mode, and the cathode of the second voltage regulator tube and the second end of the second capacitor are connected to the second end of a primary winding of the transformer module in a shared mode.

In one embodiment, the rectification and freewheeling module comprises: the first diode, the second diode and the first inductor;

the anode of the first diode is connected with the first end of the secondary winding of the transformer module, the cathode of the first diode and the cathode of the second diode are connected to the first end of the first inductor in a sharing mode, the second end of the first inductor is used as a positive polarity output end of the welding power supply circuit, and the anode of the second diode and the second end of the secondary winding of the transformer module are used as negative polarity ends of the welding power supply circuit.

In one embodiment, the auxiliary voltage reduction module includes: the first switch unit is connected with the third diode and the fifth resistor;

the cathode of the third diode is connected with the positive polarity output end of the rectification and freewheeling module, the anode of the third diode is connected with the first end of the fifth resistor, the second end of the fifth resistor is connected with the first end of the first switch unit, the second end of the first switch unit is connected with the positive polarity end of the auxiliary voltage source, and the negative polarity end of the auxiliary voltage source is connected with the negative polarity output end of the rectification and freewheeling module.

In one embodiment, the voltage regulation module comprises: a sixth resistor and a second switching unit;

the first end of the sixth resistor is connected with the positive polarity output end of the rectification and freewheeling module, the second end of the sixth resistor is connected with the first end of the second switch unit, and the second end of the second switch unit is connected with the negative polarity output end of the rectification and freewheeling module.

In one embodiment, the second switch unit includes an electronic switch, a first end of the electronic switch is connected to the second end of the sixth resistor, a second end of the electronic switch is connected to the negative polarity output end of the rectification and freewheeling module, and a control end of the electronic switch is connected to a voltage control signal, where the voltage control signal is used to control a switching state of the electronic switch.

The second aspect of the embodiments of the present application also provides a welding power supply apparatus including the welding power supply circuit according to any one of the above-mentioned embodiments.

A third aspect of embodiments of the present application further provides a welding machine, including a welding power supply circuit as described in any one of the above.

The embodiment of the application provides a welding power supply circuit, welding power supply unit and electric welding, through first gate drive module basis first gate drive signal of first original drive signal generation, second gate drive module basis the original drive signal of second generates second gate drive signal, first gate drive signal with second gate drive signal drive first power tube switch module with second power tube switch module switches on in turn to it is right through rectification and afterflow module the voltage signal of transformer module output carries out rectification and afterflow and handles to the realization is to the purpose that open circuit voltage adjusted, solves current welding power supply's open circuit voltage and mostly can not adjust, or just can adjust but the adjustment range is little at a minimum, the relatively poor problem of welding process adaptability.

Drawings

Fig. 1 is a schematic structural diagram of a welding power supply circuit according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of another exemplary welding power supply circuit according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of another exemplary welding power supply circuit according to an embodiment of the present disclosure;

fig. 4 is a schematic diagram of another application of a welding power circuit according to an embodiment of the present disclosure.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, refer to an orientation or positional relationship illustrated in the drawings for convenience in describing the present application and to simplify description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

The present embodiment provides a welding power circuit, and referring to fig. 1, the welding power circuit in the present embodiment includes a first power transistor switch module 10, a transformer module 20, a second power transistor switch module 30, a first gate driver module 40, a second gate driver module 50, and a rectifying and freewheeling module 60. Specifically, the current input end of the first power tube switch module 10 is connected to the positive polarity end VBUS + of the dc bus; the first end of the primary winding of the transformer module 20 is connected with the current output end of the first power tube switch module 10; the current input end of the second power tube switch module 30 is connected with the second end of the primary winding of the transformer module 20, and the current output end of the second power tube switch module 30 is connected with the negative polarity end VBUS-of the direct current bus; the first gate driving module 40 is configured to receive a first original driving signal and generate a first gate driving signal according to the first original driving signal; the second gate driving module 50 is configured to receive the second original driving signal and generate a second gate driving signal according to the second original driving signal; the first gate driving signal and the second gate driving signal may respectively drive the first power transistor switch module 10 and the second power transistor switch module 30 to be alternately turned on; the rectifying and freewheeling module 60 is connected to the secondary winding of the transformer module 20 for rectifying and freewheeling the voltage signal output by the transformer module 20.

In this embodiment, the first power tube switch module 10, the transformer module 20, the second power tube switch module 30, the first gate drive module 40, and the second gate drive module 50 form an inverter portion of a double-tube forward topology circuit, which is used to convert direct current provided by a direct current bus into alternating current, and in cooperation with the gate drive circuits (i.e., the first gate drive module 40 and the second gate drive module 50) with the function of driving negative voltage generation, the first power tube switch module 10 and the second power tube switch module 30 can realize a negative voltage preset function in the alternate conducting process, so that the first power tube switch module 10 and the second power tube switch module 30 can realize reliable negative voltage turn-off. Specifically, parasitic capacitors (for example, drain-source parasitic capacitors) exist in both the first power tube switch module 10 and the second power tube switch module 30, and the transformer module 20 is operated in an extremely low energy transfer density state by driving the first power tube switch module 10 and the second power tube switch module 30 to be alternately turned on, and the maximum peak voltage drop of the secondary winding thereof is about half of that in normal operation, so that the open-circuit voltage of the welding power source can be adjusted in a large range by directly adjusting the switching frequencies of the first power tube switch module 10 and the second power tube switch module 30, and the optimal open-circuit arc starting voltage can be applied specifically according to different welding process characteristics, so as to achieve the optimal configuration of the arc starting voltage.

As an embodiment of the present application, a frequency hopping technique may be further used to reduce the equivalent driving frequency of the upper and lower switching tubes in the two-tube forward topology circuit formed by the first power tube switching module 10 and the second power tube switching module 30, so as to further reduce the average energy transfer density of the transformer module 20, and thus, the open-circuit voltage may be controlled to reach a lower voltage by the main power switching tube (i.e., the first power tube switching module 10 and the second power tube switching module 30), so that the welding power supply may more easily meet various safety requirements. Specifically, the open-circuit voltage of the welding power supply circuit is adjusted by adjusting the duty ratio of the first original driving signal and the second original driving signal.

In one embodiment, referring to fig. 2, the welding power supply circuit further includes a voltage regulation module 70, the voltage regulation module 70 coupled to the rectifying and freewheeling module 60 for regulating the open circuit voltage output by the rectifying and freewheeling module 60 based on an input voltage control signal.

In the present embodiment, the open circuit voltage output by the rectification and freewheeling module 60 is regulated by providing a voltage regulation module 70 and an input voltage control signal at the output of the welding power supply circuit. For example, the voltage regulation module 70 connected in parallel at the output end of the welding power supply circuit may be formed by connecting a resistive load and an electronic switch in series, and by controlling the on-off state of the electronic switch, the resistance output by the power supply is changed from a non-adjustable "dead load" to an adjustable "live load", which not only can realize the effect of a constant resistive load, but also can control the switching frequency of the power switch tube by a PWM driving signal (i.e., a voltage control signal) to control the equivalent resistance connected to the output end of the welding power supply circuit in a negative pressure preset operating mode, thereby reducing the open-circuit voltage and realizing the adjustment of the open-circuit voltage.

In one embodiment, referring to fig. 3, the welding power supply circuit further includes an auxiliary voltage step-down module 80, the auxiliary voltage step-down module 80 being configured to output an auxiliary voltage source V1 according to an input auxiliary power control signal.

In this embodiment, the auxiliary voltage-reducing module 80 may input an auxiliary power control signal according to a user requirement, so that the auxiliary voltage-reducing module 80 outputs the auxiliary voltage source V1, where the auxiliary voltage source V1 may be a safe voltage source.

In specific application, the high and low degree of open circuit voltage influences the performance of arcing and arc stabilization, and the higher the open circuit voltage is, the easier the arc striking and arc stabilization are, especially for some special welding processes, have certain requirement to open circuit voltage size, through auxiliary voltage reduction module 80 output auxiliary voltage source V1, can switch between open circuit state and welding operating condition, not only can guarantee good arcing performance, can be fine solution common problem that can not satisfy the ann rule moreover.

As a preferred embodiment of the present application, the auxiliary voltage-dropping module 80 may also sense a load change of the output terminal and output a corresponding open-circuit voltage according to the load change of the output terminal. Furthermore, the device can also be mixed with a negative pressure preset mode of a welding power supply circuit to work cooperatively so as to achieve the purpose of compositely adjusting the open-circuit voltage of the welding power supply.

In one embodiment, referring to FIG. 4, the first gate drive module 40 comprises: the circuit comprises a first resistor R1, a second resistor R2, a first voltage regulator tube Z1 and a first capacitor C1; a first end of the first resistor R1 is connected to a positive polarity end of the first original driving signal source, a second end of the first resistor R1 and a first end of the second resistor R2 are connected to a control end of the first power transistor module 10 in common, a second end of the second resistor R2, an anode of the first regulator tube Z1 and a first end of the first capacitor C1 are connected to a negative polarity end of the first original driving signal source in common, and a cathode of the first regulator tube Z1 and a second end of the first capacitor C1 are connected to a first end of a primary winding of the transformer module 20 in common.

In this embodiment, the first gate driving module 40 is configured to receive a first original driving signal Vgs1, and the first original driving signal Vgs1 is adjusted by a negative voltage generating circuit composed of a gate resistor (i.e., a first resistor R1), a pull-down resistor (i.e., a second resistor R2), a first voltage regulator Z1 and a first capacitor C1 to generate a first gate driving signal, so as to control the on and off of the first power transistor switch module 10.

As an embodiment of the present application, referring to fig. 4, the second gate driving module 50 includes: a third resistor R3, a fourth resistor R4, a second capacitor C2 and a second voltage regulator tube Z2; a first end of the third resistor R3 is connected to the positive polarity end of the second original driving signal source, a second end of the third resistor R3 and a first end of the fourth resistor R4 are commonly connected to the control end of the second power transistor module 30, a second end of the fourth resistor R4, a first end of the second capacitor C2 and an anode of the second regulator tube Z2 are commonly connected to the negative polarity end of the second original driving signal source, and a cathode of the second regulator tube Z2 and a second end of the second capacitor C2 are commonly connected to the second end of the primary winding of the transformer module 20.

In this embodiment, the second gate driving module 50 is configured to receive a second original driving signal Vgs2, and the second original driving signal Vgs2 is adjusted by a negative voltage generating circuit composed of a gate resistor (i.e., a third resistor R3), a pull-down resistor (i.e., a fourth resistor R4), a second voltage regulator Z2 and a second capacitor C2 to generate a second gate driving signal, so as to control the second power transistor switch module 30 to turn on and off.

As an embodiment of the present application, referring to fig. 4, the first power transistor switch module 10 includes a first power transistor M1, a drain of the first power transistor M1 is connected to the positive polarity terminal VBUS + of the dc bus as a current input terminal of the first power transistor module 10, a source of the first power transistor M1 is connected to the first terminal of the primary winding of the transformer module 20 as a current output terminal of the first power transistor module 10, and a gate of the first power transistor M1 is connected to the first gate driving module 40 as a control terminal of the first power transistor module 10.

As an embodiment of the present application, referring to fig. 4, the second power transistor switch module 30 includes a second power transistor M2, a drain of the second power transistor M2 is connected to the second end of the primary winding of the transformer module 20 as a current input end of the second power transistor switch module 30, a source of the second bulk power transistor M2 is connected to the negative polarity end VBUS-of the dc bus as a current output end of the second power transistor module 30, and a gate of the second power transistor M2 is connected to the second gate driving module 50 as a control end of the second power transistor module 30.

As an embodiment of the present application, the first power transistor M1 and the second power transistor M2 are both N-type MOS transistors.

Referring to fig. 4, the transformer module 20 includes a transformer T1, a primary winding of the transformer T1 is used as the primary winding of the transformer module 20, and a secondary winding of the transformer T1 is used as the secondary winding of the transformer module 20.

In this embodiment, the drain of the first power tube M1 is connected to the positive polarity terminal VBUS + of the dc bus, the source of the first power tube M1 is connected to the first terminal of the primary winding of the transformer T1, the drain of the second power tube M2 is connected to the second terminal of the primary winding of the transformer T1, and the source of the second power tube M2 is connected to the negative polarity terminal VBUS-of the dc bus.

Ideally, only when the first power tube M1 and the second power tube M2 are simultaneously turned on, a current flows through the primary winding of T1 to drive the transformer T1 to operate, but when the first power tube M1 or the second power tube M2 is separately turned on due to the parasitic capacitance Cds existing between the drain and source electrodes of the first power tube M1 and the second power tube M2, a loop for charging the parasitic capacitance Cds through the primary winding of the transformer T1 is formed, and the parasitic capacitance Cds does not disappear until the loop is filled with the parasitic capacitance Cds, and this process also transfers energy to the secondary winding of the transformer T1. For example, assume that the on-resistance of the first power tube M1 is Rds1, the drain-source parasitic capacitance of the first power tube M1 is Cds1, the on-resistance of the second power tube M2 is Rds2, and the drain-source parasitic capacitance of the second power tube M2 is Cds 2; the first power tube M1 and the second power tube M2 work in an alternating conduction mode, when the first power tube M1 is conducted, the second power tube M2 is in an off state, a charging loop is formed at this time, the charging loop is formed, the positive polarity end VBUS + of the direct current bus sequentially flows through the Rds1, the primary winding of the transformer T1, the Cds2 to the negative polarity end VBUS-of the direct current bus, the Cds1 close to zero voltage is charged, and meanwhile, the Cds1 is rapidly discharged to the zero voltage by the Rds 1; when the second power tube M2 is turned on, the first power tube M1 is in an off state, and a charging loop is formed from the positive polarity end VBUS + of the dc bus bar to the negative polarity end VBUS-of the dc bus bar, which sequentially flows through Cds1, the primary winding of the transformer T1, and Rds2, to charge Cds1 which is discharged to a voltage close to zero during the turn-on period of the first power tube M1, and at the same time, Cds2 is rapidly discharged to a voltage close to zero by Rds2, so as to prepare for forming the charging loop when the first power tube M1 is turned on. Because the charging process is completed instantly, and the charging current is reduced along with the gradual rise of the voltage of Cds1 or Cds2, the energy transferred to the secondary winding of the transformer T1 is much smaller than the working condition that the upper power tube and the lower power tube are conducted simultaneously in normal operation, and meanwhile, the working voltage of the primary winding of the transformer T1 is about 50% lower than that in normal operation, so that the peak value of the secondary rectification output voltage is about 50% lower than that in normal operation; then, by adjusting the duty ratio of the gate driving signals of the first power tube M1 and the second power tube M2, the energy and voltage transmitted to the secondary side of the transformer can be controlled.

Furthermore, the welding power supply circuit in the embodiment can also reduce the driving frequency of the gate driving signal by using a frequency hopping technology, and can further reduce the energy density transmitted to the secondary side of the transformer, so that the open-circuit voltage of the power supply is easier to control and lower in power consumption, and the adjustment of the output open-circuit voltage is realized.

As an embodiment of the present application, in cooperation with a gate driving circuit having a function of driving negative voltage generation, the first power transistor M1 and the second power transistor M2 can implement a negative voltage presetting function during an alternate conduction process, so that the first power transistor M1 and the second power transistor M2 implement reliable negative voltage shutoff. For example, taking the driving circuit of the first power transistor M1 as an example, when the first original driving signal Vgs1 is at a high level, the first original driving signal Vgs1 charges the gate-source capacitor Cgs1 of the first power transistor M1 through the first resistor R1, and when the first original driving signal Vgs1 is higher than the conduction voltage Vgsth to the first power transistor M1, the first power transistor M1 is turned on, and at the same time, the first capacitor C1 is also charged until the regulated voltage value of the regulator connected in parallel with the first power transistor M1 is reached, at this time, the source terminal of the first power transistor M1 is positive, and the Vgs1 terminal is negative; when Vgs1 becomes low, Vgs1+ is equipotential with Vgs1 —, the gate terminal of the first power tube M1 is equipotential with Vgs1+, and since the voltage of the first capacitor C1 remains unchanged for a short time, the gate voltage of the first power tube M1 is negative with respect to the source of the first power tube M1, and the magnitude of the voltage is equal to the voltage across the first capacitor C1, and the negative voltage of the first power tube M1 is turned off, so the operation mode in which the gates of the first power tube M1 and the second power tube M2 are alternately turned on is called a negative voltage preset mode in which the gates of the power tubes are set to be negative.

In one embodiment, referring to fig. 4, the rectification and freewheeling module 60 includes: a first diode D1, a second diode D2, and a first inductor L1; an anode of the first diode D1 is connected to a first end of the secondary winding of the transformer module 20, a cathode of the first diode D1 and a cathode of the second diode D2 are commonly connected to a first end of the first inductor L1, a second end of the first inductor L1 serves as a positive polarity output end of the welding power supply circuit, and an anode of the second diode D2 is connected to a second end of the secondary winding of the transformer module 20.

In the embodiment, the secondary winding of the transformer T1, the rectifying diode (i.e., the first diode D1), the freewheeling diode (i.e., the second diode D2) and the output inductor (i.e., the first inductor L1) form a rectifying and freewheeling portion of a dual-transistor forward topology circuit, during the operation of the transformer T1, the first diode D1 is turned on in the forward direction, the second diode D2 is turned off in the reverse direction, the first inductor L1 is charged to store energy, during the intermittence of the transformer T1, the first diode D1 is turned off in the reverse direction, the second diode D2 is turned on in the forward direction to freewheel, and the first inductor L1 releases energy.

In one embodiment, referring to fig. 4, the auxiliary voltage-reducing module 80 includes: a third diode D3, a fifth resistor R5, a first switching unit S1, and an auxiliary voltage source V1; a cathode of the third diode D3 is connected to the positive output terminal of the rectification and freewheeling module 60, an anode of the third diode D3 is connected to a first terminal of a fifth resistor R5, a second terminal of the fifth resistor R5 is connected to a first terminal of a first switching unit S1, a second terminal of the first switching unit S1 is connected to a positive terminal of an auxiliary voltage source V1, and a negative terminal of the auxiliary voltage source V1 is connected to a negative output terminal of the rectification and freewheeling module 60.

In this embodiment, the auxiliary voltage dropping module 80 utilizes an independent safety voltage source (i.e., the auxiliary voltage source V1) to output an open-circuit voltage meeting the safety requirements, for example, the auxiliary voltage dropping module 80 may be activated when an open-circuit voltage lower than the dc 36V needs to be output, and the auxiliary voltage dropping module 80 may adjust the open-circuit voltage of the welding power circuit when the main power output circuit is turned off (e.g., the first power tube M1 and the second power tube M2 are turned off), that is, the auxiliary voltage dropping module 80 may operate independently based on the auxiliary voltage source V1 and the first switching unit S1, or may operate cooperatively after being mixed with a negative voltage preset mode of the welding power circuit, so as to achieve the purpose of adjusting the open-circuit voltage of the welding power compositely.

As an example of the application, the first switching unit S1 may be a MOS Transistor, a Bipolar Junction Transistor (BJT), a relay contact, or the like.

In one embodiment, referring to fig. 4, the voltage regulation module 70 includes: a sixth resistor R6 and a second switching unit S2; a first terminal of the sixth resistor R6 is connected to the positive polarity output terminal of the rectification and freewheeling module 60, a second terminal of the sixth resistor R6 is connected to a first terminal of the second switching unit S2, and a second terminal of the second switching unit S2 is connected to the negative polarity output terminal of the rectification and freewheeling module 60.

In this embodiment, the voltage regulating module 70 may have two operation modes, one is to control the second switch unit S2 to be normally open, so that the sixth resistor R6 is used as a fixed load of the power output terminal, and then the duty ratio of the gate driving signals of the first power transistor M1 and the second power transistor M2 is adjusted in a closed loop in the negative preset mode to achieve the purpose of adjusting the open-circuit voltage; in the other mode, in the negative-pressure preset mode, according to the magnitude of the target open-circuit voltage, a trip frequency number and a proper duty ratio are preset for gate driving signals of the first power tube M1 and the second power tube M2, and then the second switching unit S2 is driven by a voltage control signal to control an equivalent resistor connected to the output end of the power supply, so that the open-circuit voltage is reduced, and the open-circuit voltage is adjusted.

As an embodiment of the application, the gate driving signals of the first power transistor M1 and the second power transistor M2 are pulse width modulation signals (PWM signals), wherein the gate of the first power transistor M1 is connected to the first gate driving signal, the gate of the second power transistor M2 is connected to the second gate driving signal, and the open-circuit voltage of the welding power circuit can be automatically adjusted by adjusting the duty ratio of the first gate driving signal and the second gate driving signal in a closed loop in the negative voltage preset mode.

Further, as a preferred embodiment of the present application, the voltage control signal for controlling the switching state of the second switching unit S2 is a pulse width modulation signal, and the switching frequency of the second switching unit S2 can be adjusted by adjusting the duty ratio of the voltage control signal, so as to adjust the equivalent resistance that is connected to the output terminal of the power supply, thereby implementing the adjustment of the open-circuit voltage.

In one embodiment, referring to fig. 4, the second switch unit S2 includes an electronic switch, a first terminal of the electronic switch is connected to the second terminal of the sixth resistor R6, a second terminal of the electronic switch is connected to the negative polarity output terminal of the rectification and freewheeling module 60, and a control terminal of the electronic switch is connected to a voltage control signal, wherein the voltage control signal is used for controlling a switching state of the electronic switch.

As an embodiment of the present application, the electronic switch may be a MOS Transistor, a Bipolar Junction Transistor (BJT), a relay contact, or the like.

The embodiment of the application also provides a welding power supply device which comprises the welding power supply circuit.

The embodiment of the application also provides the electric welding machine, which comprises the welding power supply circuit.

In specific implementation, the electric welding machine is an inverter electric welding machine and can be loaded and used for welding.

The embodiment of the application adopts an innovative main power driving circuit and a working mode, novel VES (auxiliary voltage reduction module 80) and OVA (voltage regulation module 70) modules, unique frequency hopping control technology, and open-circuit voltage software control strategies set for different welding process requirements, and realizes large-range adjustment of the open-circuit voltage of the welding power supply in multiple modes, thereby solving the problems that the existing welding power supply open-circuit voltage cannot meet various safety regulations and the requirements of different welding process procedures on the open-circuit voltage due to the fact that the existing welding power supply open-circuit voltage cannot be adjusted or adjusted in a limited range, and the like, and achieving the effects of avoiding the common problem that the safety regulations cannot be met and realizing the optimal configuration of arcing and arc stabilizing voltage of different welding process procedures.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. A welding power supply circuit, comprising:

2. The welding power supply circuit of claim 1, wherein the welding power supply circuit further comprises:

3. The welding power supply circuit of claim 1, wherein the welding power supply circuit further comprises:

4. The welding power supply circuit of claim 1, wherein the first gate drive module comprises: the circuit comprises a first resistor, a second resistor, a first voltage regulator tube and a first capacitor;

the first end of the first resistor is connected with the positive polarity end of a first original driving signal source, the second end of the first resistor and the first end of the second resistor are connected with the control end of the first power tube switch module in a sharing mode, the second end of the second resistor, the anode of the first voltage-regulator tube and the first end of the first capacitor are connected with the negative polarity end of the first original driving signal source in a sharing mode, and the cathode of the first voltage-regulator tube and the second end of the first capacitor are connected with the first end of a primary winding of the transformer module in a sharing mode;

5. The welding power supply circuit of claim 1, wherein the rectification and freewheel module comprises: the first diode, the second diode and the first inductor;

6. The welding power supply circuit of claim 3, wherein the auxiliary voltage reduction module comprises: the first switch unit is connected with the third diode and the fifth resistor;

7. The welding power supply circuit of claim 2, wherein the voltage regulation module comprises: a sixth resistor and a second switching unit;

8. The welding power supply circuit of claim 7, wherein the second switching unit comprises an electronic switch, a first terminal of the electronic switch is coupled to the second terminal of the sixth resistor, a second terminal of the electronic switch is coupled to the negative polarity output terminal of the rectification and freewheeling module, and a control terminal of the electronic switch is coupled to a voltage control signal, wherein the voltage control signal is configured to control a switching state of the electronic switch.

9. Welding power supply apparatus, characterized in that it comprises a welding power supply circuit according to any of claims 1-8.

10. A welding machine comprising a welding power supply circuit as claimed in any one of claims 1 to 8.