阅读说明：本技术 一种电网电源与储能电源自适应切换的焊机控制电路 (Welding machine control circuit for self-adaptive switching of power grid power supply and energy storage power supply ) 是由 舒振宇 雷斌 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种电网电源与储能电源自适应切换的焊机控制电路,包括降压逆变模块,用于将交流电转换高频交流电后再转换为低压直流电输出,包括第一整流电路、逆变电路、开关电源电路,第一整流电路的输入连接电网电源,其输出连接逆变电路的输入,还包括依次连接的升压模块、切换电路,升压模块的输入连接储能电源,用于将储能电源的低电压升压到设定电压值,切换电路的输出分别连接逆变电路的输入、开关电源电路的输入,切换电路根据第一整流电路的输出大小与设定电压值的大小,自适应地在电网电源与储能电源之间进行切换。本申请通过电网电源与储能电源切换连接逆变降压电路,简化了电路结构,降低了焊机成本。(The invention discloses a welding machine control circuit for self-adaptive switching of a power grid power supply and an energy storage power supply, which comprises a voltage reduction inversion module, a first rectification circuit, an inversion circuit and a switch power supply circuit, wherein the voltage reduction inversion module is used for converting alternating current into high-frequency alternating current and then converting the alternating current into low-voltage direct current for output. This application is switched with the energy storage power supply through the electric wire netting power and is connected contravariant step-down circuit, has simplified circuit structure, has reduced the welding machine cost.)

1. The utility model provides a welding machine control circuit that grid power and energy storage power self-adaptation switch, includes step-down contravariant module for convert low voltage direct current output again after alternating current conversion high frequency alternating current, including first rectifier circuit, inverter circuit, switching power supply circuit, the input connection grid power of first rectifier circuit, its output connection inverter circuit's input, its characterized in that: the low-voltage energy storage power supply comprises a boosting module and a switching circuit which are sequentially connected, wherein the input of the boosting module is connected with an energy storage power supply and used for boosting the low voltage of the energy storage power supply to a set voltage value, the output of the switching circuit is respectively connected with the input of an inverter circuit and the input of a switching power supply circuit, and the switching circuit adaptively switches between a power grid power supply and the energy storage power supply according to the output of a first rectifying circuit and the set voltage value.

2. The welder control circuit of grid power supply and energy storage power supply self-adaptation switching of claim 1, characterized in that: the boosting module comprises a first boosting module and a second boosting module, wherein the input of the first boosting module and the input of the second boosting module are connected with an energy storage power supply, the output of the first boosting module is connected with the input of the inverter circuit after passing through the switching circuit, and the switching circuit is used for supplying power to the inverter circuit by the energy storage power supply when the power supply of the power grid does not meet the requirement; the output of the second boosting module is connected with the input of the switching power supply circuit after passing through the switching circuit and used for providing power for the switching power supply circuit by the energy storage power supply when the power supply of the power grid power supply does not meet the requirement.

3. The welder control circuit of grid power supply and energy storage power supply self-adaptation switching of claim 2, characterized in that: the first boosting module comprises a first boosting circuit and a first PWM (pulse width modulation) adjusting circuit which are sequentially connected, the first boosting circuit is used for boosting the voltage of the energy storage power supply to a voltage set value, the first PWM adjusting circuit is used for adjusting a first PWM signal according to the output size of the first boosting circuit, and the output of the first boosting circuit is adjusted to be stable.

4. The welder control circuit of grid power supply and energy storage power supply self-adaptation switching according to claim 3, characterized in that: the first BOOST circuit comprises a first BOOST topology circuit, and the first PWM adjusting circuit comprises a first voltage sampling circuit and a first PWM adjusting chip which are connected in sequence; the first voltage sampling circuit samples the output of the first BOOST topology circuit, and the first PWM adjusting chip adjusts the output of the first PWM signal according to the magnitude of the first sampling voltage, so that the output of the first BOOST topology circuit is controlled.

5. The welder control circuit of grid power supply and energy storage power supply self-adaptation switching of claim 2, characterized in that: the second boost module comprises a second boost circuit and a second PWM (pulse width modulation) adjusting circuit which are sequentially connected, the second boost circuit is used for boosting the voltage of the energy storage power supply to a voltage set value, and the second PWM adjusting circuit is used for adjusting a second PWM signal according to the output magnitude of the second boost circuit and adjusting the output stability of the second boost circuit.

6. The welder control circuit of grid power supply and energy storage power supply self-adaptation switching of claim 1, characterized in that: the switching circuit comprises a one-way conduction circuit, when the output of the first rectifying circuit is greater than or equal to a set voltage value, the power grid power supply provides electric energy, and when the output of the first rectifying circuit is smaller than the set voltage value, the energy storage power supply provides electric energy.

7. The welder control circuit of grid power supply and energy storage power supply self-adaptation switching of claim 1, characterized in that: the input of the second rectifying circuit is connected with a power grid power supply, and the output of the second rectifying circuit is connected with the input of the switching power supply after passing through the switching circuit and is used for providing electric energy for the switching power supply circuit.

8. The welder control circuit of grid power supply and energy storage power supply self-adaptation switching according to claim 7, characterized in that: the switching circuit comprises at least three one-way conduction circuits, the positive end of the first one-way conduction circuit is connected with the positive output of the first boosting module, and the negative end of the first one-way conduction circuit is connected with the positive input of the inverter circuit; the positive end of the second one-way conduction circuit is connected with the positive output of the second boosting module, and the negative end of the second one-way conduction circuit is connected with the positive input of the switching power supply circuit; the positive end of the third one-way conduction circuit is connected with the positive output of the second rectifying circuit, and the negative end of the third one-way conduction circuit is connected with the positive input of the switching power supply circuit.

9. A welding machine control method for self-adaptive switching of a power grid power supply and an energy storage power supply is characterized by comprising the following steps: the power grid power supply is rectified to obtain rectified voltage, the energy storage power supply is boosted to obtain a voltage set value, when the rectified voltage is larger than or equal to the voltage set value, the switching circuit is switched to provide electric energy for the voltage reduction inversion module, when the rectified voltage is smaller than the voltage set value, the switching circuit is switched to provide electric energy for the voltage reduction inversion module, and the energy storage power supply is used for providing electric energy for the voltage reduction inversion module.

10. The welding machine control method for the self-adaptive switching of the power grid power supply and the energy storage power supply according to claim 9, characterized by comprising the following steps of: and two paths of boosting circuits are adopted to boost the energy storage power supply and are respectively used for providing electric energy for an inverter circuit and a switching power supply circuit in the voltage reduction inverter module.

Technical Field

The invention relates to the technical field of circuit control, in particular to a welding machine control circuit for self-adaptive switching of a power grid power supply and an energy storage power supply.

Background

At present, a welding machine has two power supply modes, namely power supply by an energy storage battery and power supply by a power grid, when the energy storage battery supplies power, a high-voltage direct-current battery pack is generally adopted for supplying power, and the high-voltage direct-current battery pack controls the magnitude of output current after chopping and voltage reduction; when the power grid supplies power, the alternating current of the power grid is rectified and inverted, and then is reduced by the transformer to control the output current.

In order to expand the applicability of the welding machine, the welding machine can adopt a power grid power supply and simultaneously can support the energy storage power supply, when the power grid power supply and the energy storage power supply are compatible, the problem of electrical isolation between high voltage and low voltage needs to be solved due to safety considerations, one path of inverting step-down circuit needs to be arranged on the energy storage power supply, the other path of inverting step-down circuit needs to be arranged on the power grid power supply, the two paths of inverting step-down circuits cause a complex circuit structure, and the welding machine is high in cost.

Therefore, designing a simplified welder circuit, being compatible with power supply of a power grid and energy storage power supply, and reducing the cost of the welder is a problem to be solved urgently at present.

Disclosure of Invention

The invention aims to provide a welding machine control circuit for self-adaptive switching of a power grid power supply and an energy storage power supply, wherein the energy storage power supply is boosted to a voltage set value, is connected to the front end of an inverter circuit of an inverter step-down circuit and the front end of a switch power supply circuit through a switching circuit, and is switched to the power grid power supply for supplying power when the rectified voltage of the power grid power supply after rectification is greater than or equal to the voltage set value; when the rectified voltage is smaller than the voltage set value, the energy storage power supply is switched to supply power, and one inverter voltage reduction circuit is used under the condition that the energy storage power supply is compatible with the power grid power supply, so that the circuit structure is simplified, and the cost of the welding machine is reduced.

In a first aspect, the above object of the present invention is achieved by the following technical solutions:

the utility model provides a welding machine control circuit of electric wire netting power and energy storage power self-adaptation switching, including step-down contravariant module, be used for converting the low voltage direct current output into again behind the alternating current conversion high frequency alternating current, including first rectifier circuit, inverter circuit, switching power supply circuit, the input connection electric wire netting power of first rectifier circuit, its output connection inverter circuit's input, still include the module that steps up that connects gradually, switching circuit, the input connection energy storage power of the module that steps up, a low voltage for with energy storage power is stepped up to the settlement voltage value, inverter circuit's input is connected respectively in switching circuit's output, switching circuit's input, switching circuit switches over between electric wire netting power and energy storage power according to the output size of first rectifier circuit and the size of settlement voltage value, self-adaptation ground switches over between electric wire netting power and energy storage power.

The invention is further configured to: the boosting module comprises a first boosting module and a second boosting module, wherein the input of the first boosting module and the input of the second boosting module are connected with an energy storage power supply, the output of the first boosting module is connected with the input of the inverter circuit after passing through the switching circuit, and the switching circuit is used for supplying power to the inverter circuit by the energy storage power supply when the power supply of the power grid does not meet the requirement; the output of the second boosting module is connected with the input of the switching power supply circuit after passing through the switching circuit and used for providing power for the switching power supply circuit by the energy storage power supply when the power supply of the power grid power supply does not meet the requirement.

The invention is further configured to: the first boosting module comprises a first boosting circuit and a first PWM (pulse width modulation) adjusting circuit which are sequentially connected, the first boosting circuit is used for boosting the voltage of the energy storage power supply to a voltage set value, the first PWM adjusting circuit is used for adjusting a first PWM signal according to the output size of the first boosting circuit, and the output of the first boosting circuit is adjusted to be stable.

The invention is further configured to: the first BOOST circuit comprises a first BOOST topology circuit, and the first PWM adjusting circuit comprises a first voltage sampling circuit and a first PWM adjusting chip which are connected in sequence; the first voltage sampling circuit samples the output of the first BOOST topology circuit, and the first PWM adjusting chip adjusts the output of the first PWM signal according to the magnitude of the first sampling voltage, so that the output of the first BOOST topology circuit is controlled.

The invention is further configured to: the second boost module comprises a second boost circuit and a second PWM (pulse width modulation) adjusting circuit which are sequentially connected, the second boost circuit is used for boosting the voltage of the energy storage power supply to a voltage set value, and the second PWM adjusting circuit is used for adjusting a second PWM signal according to the output magnitude of the second boost circuit and adjusting the output stability of the second boost circuit.

The invention is further configured to: the switching circuit comprises a one-way conduction circuit, when the output of the first rectifying circuit is greater than or equal to a set voltage value, the power grid power supply provides electric energy, and when the output of the first rectifying circuit is smaller than the set voltage value, the energy storage power supply provides electric energy.

The invention is further configured to: the input of the second rectifying circuit is connected with a power grid power supply, and the output of the second rectifying circuit is connected with the input of the switching power supply after passing through the switching circuit and is used for providing electric energy for the switching power supply circuit.

The invention is further configured to: the switching circuit comprises at least three one-way conduction circuits, the positive end of the first one-way conduction circuit is connected with the positive output of the first boosting module, and the negative end of the first one-way conduction circuit is connected with the positive input of the inverter circuit; the positive end of the second one-way conduction circuit is connected with the positive output of the second boosting module, and the negative end of the second one-way conduction circuit is connected with the positive input of the switching power supply circuit; the positive end of the third one-way conduction circuit is connected with the positive output of the second rectifying circuit, and the negative end of the third one-way conduction circuit is connected with the positive input of the switching power supply circuit.

In a second aspect, the above object of the present invention is achieved by the following technical solutions:

a welding machine control method for self-adaptive switching of a power grid power supply and an energy storage power supply comprises the steps of rectifying the power grid power supply to obtain rectified voltage, boosting the energy storage power supply to obtain a voltage set value, switching a switching circuit when the rectified voltage is larger than or equal to the voltage set value, supplying electric energy to a voltage reduction inversion module by the power grid power supply, switching the switching circuit when the rectified voltage is smaller than the voltage set value, and supplying electric energy to the voltage reduction inversion module by the energy storage power supply.

The invention is further configured to: and two paths of boosting circuits are adopted to boost the energy storage power supply and are respectively used for providing electric energy for an inverter circuit and a switching power supply circuit in the voltage reduction inverter module.

Compared with the prior art, the beneficial technical effects of this application do:

1. according to the method and the device, the switching circuit is arranged, automatic switching is carried out between the power grid power supply and the energy storage power supply according to the rectified voltage of the power grid power supply and the boosted voltage set value of the energy storage power supply, and self-adaptive switching of power supply is realized;

2. furthermore, the diode is arranged in the switching circuit, and the characteristic of the diode is utilized to switch between high voltage and low voltage, so that redundant parts are not needed, and the circuit structure is simple;

3. furthermore, the voltage set value is set to be smaller than the rectified voltage of the power grid, so that the preferential connection of the power grid is guaranteed.

Drawings

FIG. 1 is a schematic diagram of a welder control circuit configuration of one embodiment of the present application;

FIG. 2 is a schematic diagram of a welder control circuit configuration of yet another embodiment of the present application;

FIG. 3 is a schematic diagram of a first boost module configuration according to yet another embodiment of the present application;

fig. 4 is a schematic diagram of a second boost module according to yet another embodiment of the present application.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Detailed description of the preferred embodiment

The utility model provides a welding machine control circuit that grid power and energy storage power self-adaptation switched, as shown in FIG. 1, including step-down contravariant module, step-up module, switching module, the input connection grid power of step-down contravariant module, including first rectifier circuit BR1, inverter circuit, switching power supply circuit, welding machine master control circuit, step-down circuit, secondary rectifier circuit.

First rectifier circuit BR1, inverter circuit, step-down circuit, secondary rectifier circuit connect gradually for after converting the alternating current of electric wire netting power into the direct current, be used for welded 65V high frequency alternating current through inverter circuit conversion, step-down through the transformer T1 of step-down circuit again, secondary rectifier circuit rectification back, the welding power supply of output low-voltage heavy current supplies the welding machine to use.

The switching power supply circuit and the welding machine main control circuit are sequentially connected and used for controlling the conduction frequency of the inverter circuit and controlling the output power of the voltage reduction inverter module.

The boosting module and the switching module are sequentially connected, the input of the boosting module is connected with the output of the energy storage power supply, one output of the switching module is connected with the input end of the inverter circuit, and the other output of the switching module is connected with the input end of the switching power supply circuit.

The first rectification circuit BR1 of the step-down inversion module is used for rectifying 220V alternating current of a power grid power supply to obtain 310V rectified direct current, and outputting the 310V rectified direct current to the inversion circuit, the inversion circuit converts the 310V direct current into high-frequency alternating current according to a control signal output by the welding machine main control circuit, the high-frequency is controlled by the control signal frequency of the welding machine main control circuit, the high-frequency alternating current is subjected to step-down by a transformer T1, and a power supply with low voltage and large current is obtained at a secondary level and is provided for the welding machine.

The boost module is used for boosting the low voltage of the energy storage power supply to a voltage set value, in the embodiment of the application, the voltage set value is 300V, and is lower than the voltage of 310V rectified direct current, and such setting provides guarantee for the power grid power supply preferentially.

After the output of the boosting module passes through the switching circuit, the first path of output is connected to the input end of the inverter circuit and the output end of the first rectifying circuit and used for providing electric energy for the inverter circuit, and the second path of output is connected to the output end of the switching power supply circuit and used for providing electric energy for the switching power supply circuit.

Specifically, the output of the first path is 300V direct current, and the output of the second path comprises 300V direct current, low-power direct current for the operation of a switching power supply circuit and a welder main control circuit, such as 15V/24V/-15V low-voltage direct current.

The switching circuit comprises a one-way conduction circuit, when the voltage of the rectified direct current is greater than or equal to a set voltage value, a first one-way conduction circuit connected with a power supply end of the power grid applies the power supply voltage of the power grid to the inverter circuit and the switch power supply circuit, and a second one-way conduction circuit connected with the boosting module is not conducted; when the voltage of the rectified direct current is smaller than the set voltage value, the second one-way conduction circuit connected with the boosting module outputs the set voltage of the boosting module to the inverter circuit and the switch power supply circuit, and the first one-way conduction circuit connected with the power supply end of the power grid is not conducted.

Detailed description of the invention

The utility model provides a welding machine control circuit that grid power and energy storage power self-adaptation switch, as shown in FIG. 2, including the step-down contravariant module, the module steps up, the switching module, second rectifier circuit BR2, the module that steps up includes first step-up module, the second step-up module, first step-up module, the energy storage power output is connected simultaneously to the input of second step-up module, the output of first step-up module is connected to the input of contravariant circuit behind the switching circuit, the output of second step-up module is connected to switching power supply circuit's input behind the switching circuit.

The first boosting module is used for providing high-power set voltage value direct current for the inverter circuit, the second boosting module is used for providing low-power set voltage value direct current and low-voltage direct current for the switching power supply circuit, and the low-voltage direct current is used for providing power for the switching power supply circuit and the welder main control circuit.

In the embodiment, the energy storage power supply is a storage battery pack and provides low-voltage direct current of 48V.

The input of the second rectifying circuit is connected with a power supply of a power grid, and the output of the second rectifying circuit is connected with the switching circuit.

The switching circuit provides electric energy for the welder by the power grid power supply when the voltage of the rectified direct current is greater than or equal to the set voltage value and provides the electric energy for the welder by the energy storage power supply when the voltage of the rectified direct current is less than the set voltage value according to the magnitude of the rectified direct current and the set voltage value.

The output of the second rectifying circuit is connected to the switching power supply circuit through a third one-way conduction circuit of the switching circuit, and similarly, when the voltage of the rectified direct current is greater than or equal to the set voltage value, the power grid power supply provides electric energy for the switching power supply circuit, and when the voltage of the rectified direct current is less than the set voltage value, the energy storage power supply provides electric energy for the switching power supply circuit.

When the alternating current input of the power grid power supply is 220V, the output of the first rectifying circuit and the output of the second rectifying circuit are 310V rectifying direct current, when the alternating current input of the power grid power supply is less than 212V, the output of the first rectifying circuit and the output of the second rectifying circuit are lower than 300V, and when the voltage of the power grid power supply is abnormal, the energy storage power supply works to ensure the power of the power supply of the welding machine.

Detailed description of the preferred embodiment

The utility model provides a first boost module in welding machine control circuit that grid power and energy storage power self-adaptation switch, as shown in fig. 3, including first boost circuit, the first PWM adjusting circuit who connects gradually, first boost circuit is used for promoting the voltage of energy storage power to the voltage set value, and first PWM adjusting circuit is used for adjusting first PWM signal according to the output size of first boost circuit, and the output of adjusting first boost circuit is stable.

The first BOOST circuit comprises a first BOOST topology circuit, and the first PWM adjusting circuit comprises a first voltage sampling circuit and a first PWM adjusting chip which are connected in sequence; the first voltage sampling circuit samples the output of the first BOOST topology circuit, and the first PWM adjusting chip adjusts the output of the first PWM signal according to the magnitude of the first sampling voltage, so that the output of the first BOOST topology circuit is controlled.

The first BOOST topology circuit comprises a second energy storage inductor L2, a third switching tube Q3, a thirty-first fast recovery diode D30 and a thirty-first fast recovery diode D31. Based on voltage and current parameters, two recovery diodes are adopted to ensure that the recovery diodes can work within a set power.

One end of the second energy storage inductor L2 is connected to the positive output end of the energy storage power supply, and the other end is connected to the input end of the third switching tube Q3, the positive end of the thirty-first fast recovery diode D30, and the positive end of the thirty-first fast recovery diode D31.

The output terminal of the third switching tube Q3 is connected to ground, and its control terminal is connected to the output terminal of the first driving circuit.

The negative output end of the energy storage power supply is connected with one end of a current detection resistor RS1, and the other end of the current detection resistor RS1 is connected with the ground end.

The first driving circuit comprises a fourth triode Q4, a twenty-third diode D23 and a first current-limiting resistor R24, the fourth triode Q4 is a PNP triode, a control end of the fourth triode Q4 is connected to a first PWM signal output end of the first PWM adjusting chip through the first current-limiting resistor R24, an output end, namely an emitter, of the fourth triode Q4 is connected to a control end of the third switching tube Q3, and a collector of the fourth triode Q4 is grounded VSS. Meanwhile, the control terminal of the fourth transistor Q4 is connected to the positive terminal of the twenty-third diode D23, and the output terminal thereof is connected to the negative terminal of the twenty-third diode D23.

The first driving circuit is used for amplifying the first PWM signal output by the first PWM adjusting chip to drive the third switching tube Q3.

A first absorption circuit is provided between the input terminal and the output terminal of the third switching tube Q3.

The first absorption circuit comprises a twenty-third capacitor C23/a twenty-second resistor R22/a twenty-third resistor R23, wherein the twenty-second resistor R22 is connected with the twenty-third resistor R23 in parallel and then is connected with a twenty-third capacitor C23 in series to form the first absorption circuit, and the first absorption circuit is used for protecting the off-state voltage between the input end and the output end of the third switching tube Q3 from exceeding the rated value of a device.

The first voltage sampling circuit comprises a resistor voltage division circuit, a series resistor R28/R29/R30/R31 forms a first sampling resistor string, a parallel resistor R32/R33 forms a second sampling resistor string, the output of the first BOOST topology circuit is divided by the first sampling resistor string and the second sampling resistor string and then input to a voltage sampling end of the first PWM adjusting chip, and the first PWM adjusting chip controls the frequency of the first PWM signal according to the size of the sampling voltage.

The first PWM adjusting chip comprises a current sampling end and a voltage sampling end and is used for adjusting output voltage according to current and voltage of the first booster circuit.

The first BOOST module further comprises a first filter circuit, wherein the first filter circuit comprises a resistor R21/R25, a capacitor C21/C22/C25/C26, a resistor R21 and a capacitor C21/C22 are connected in parallel, a resistor R25 and a capacitor C25/C26 are connected in parallel, and the two parallel connection circuits are connected in series again and used for filtering the output of the first BOOST topology circuit.

The DC ground VSS of the first boost module and the DC ground GND of the second boost module are different ground ends.

The positive end of the thirty-second diode is connected to the output end of the first BOOST topology circuit, and the negative end of the thirty-second diode is connected to the positive input end of the inverter circuit, and is used as a first one-way conduction circuit for switching the output of the first BOOST module.

Detailed description of the invention

The utility model provides a welding machine control circuit's that electric wire netting power and energy storage power self-adaptation switch second boost module, as shown in figure 4, the second boost module is used for promoting the voltage of energy storage power to the voltage setting value including the second boost circuit, the second PWM adjusting circuit that connect gradually, the second PWM adjusting circuit is used for adjusting the second PWM signal according to the output size of second boost circuit, the output of adjustment second boost circuit is stable.

The second BOOST circuit comprises a second BOOST topological circuit, and the second PWM adjusting circuit comprises a second voltage sampling circuit and a second PWM adjusting chip which are connected in sequence; the second voltage sampling circuit samples the output of the second BOOST topology circuit, and the second PWM adjusting chip adjusts the output of the second PWM signal according to the second sampling voltage, so that the output of the second BOOST topology circuit is controlled.

The second BOOST topology circuit comprises a first energy storage inductor L1, a first switch Q1, and a third fast recovery diode D3.

One end of the first energy storage inductor L1 is connected to the positive output end of the energy storage power supply, and the other end is connected to the input end of the first switch Q1 and the positive end of the third fast recovery diode D3.

The output end of the first switch tube Q1 is connected with one end of a seventeenth resistor R17 and one end of a sixteenth resistor R16; the control end of the resistor is connected with one end of a sixth resistor R6, one end of a ninth resistor R9 and the negative end of a Zener diode ZD1, and the positive end of the Zener diode ZD1 and the other end of the ninth resistor R9 are grounded.

The other end of the sixth resistor R6 is connected to the PWM signal output terminal of the second PWM adjusting chip and the negative terminal of the fourth diode D4, and the positive terminal of the fourth diode D4 is connected to the ground GND.

The PWM signal output terminal of the second PWM adjusting chip is connected to the control terminal of the first switch Q1 after passing through the current limiting resistor R6, so as to control the turn-on frequency of the first switch Q1.

A second snubber circuit is arranged between the input end and the output end of the first switch tube Q1, and the second snubber circuit comprises a seventh resistor/a sixth capacitor which are connected in series and used for protecting the turn-off voltage between the input end and the output end of the first switch tube Q1 from exceeding the rated value of a device.

The other end of the sixteenth resistor is connected to the current sampling end of the second PWM adjusting chip, and is used for sampling the output current of the second boost circuit.

The second voltage sampling circuit comprises a resistor voltage division circuit, a series resistor R4/R3/R19 forms a second sampling resistor string, the output voltage of the second BOOST topological circuit is sampled by the second sampling resistor string and a fifth resistor R5, the output of the second BOOST topological circuit is divided by the second sampling resistor string and the fifth resistor R5 and then is input to a voltage sampling end of a second PWM (pulse width modulation) adjusting chip, and the second PWM adjusting chip controls the frequency of a second PWM signal according to the size of the sampling voltage.

The second PWM adjusting chip comprises a current sampling end and a voltage sampling end and is used for adjusting output voltage according to the current and the voltage of the second booster circuit.

The second BOOST module further comprises a second filtering circuit comprising a capacitor C1/C2 connected in parallel for filtering the output of the second BOOST topology.

The positive end of the second diode is connected to the output end of the second BOOST topology circuit, and the negative end of the second diode is connected to the positive input end of the switching power supply circuit, and is used as a second one-way conduction circuit for switching the output of the second BOOST module.

And the input of the second rectifying circuit BR2 is connected with a power grid power supply, the output of the second rectifying circuit BR2 is connected with the positive end of the first diode D1, the negative end of the first diode D1 is connected with the input of the switching power supply, and the first diode D1 is used as a third unidirectional conducting circuit and used for providing electric energy for the switching power supply circuit.

In fig. 4, the energy storage power supply is further configured to output a low-voltage direct current through a conversion circuit, and convert a voltage of the energy storage power supply into a working voltage of the switching power supply circuit and a working voltage of the welder main control circuit, so as to provide electric energy for the switching power supply circuit and the welder main control circuit.

The low-voltage direct current comprises a 15V, 24V and-15V voltage power supply.

The 15V voltage conversion circuit comprises a second switch tube Q2, one end of a fourteenth resistor R14 is connected with the positive end of an energy storage power supply, the other end of the fourteenth resistor R14 is connected with the negative end of a second voltage regulator tube ZD2, the positive end of the second voltage regulator tube ZD2 is grounded GND, and the negative end of the second voltage regulator tube ZD2 is used for providing a control end voltage for the second switch tube Q2.

The tenth resistor R10 and the eleventh resistor R11 are connected in series, the twelfth resistor R12 and the thirteenth resistor R13 are connected in series, and after a series structure of the tenth resistor R10 and the eleventh resistor R11 is connected in parallel with a series structure of the twelfth resistor R12 and the thirteenth resistor R13, the series structure is connected between the input end of the second switch tube Q2 and the positive end of the energy storage power supply and used for supplying current to the second switch tube Q2.

The output end of the second switch tube Q2 is connected to the positive end of the fifth diode D5, the negative end of the fifth diode D5 serves as the output end of the 15V dc, and is connected to one end of the filter capacitor C8 and one end of the filter capacitor C9, and the other end of the filter capacitor C8 and the other end of the filter capacitor C9 are grounded to GND, so as to filter the 15V dc output.

According to the welding machine control method for self-adaptive switching of the power grid power supply and the energy storage power supply, the power grid power supply is rectified to obtain rectified voltage; and boosting the energy storage power supply to obtain output voltage, wherein the output voltage value is equal to the voltage set value. When the rectified voltage is larger than or equal to the voltage set value, the switching circuit switches, the boosting output of the energy storage power supply is prevented, the rectified output of the power grid power supply is conducted, the rectified output of the power grid power supply is applied to the input end of the inverter circuit and the input end of the switch power supply circuit, and the power grid power supply provides electric energy for the voltage reduction inverter module. When the rectified voltage is smaller than the voltage set value, the switching circuit switches, the boosting output of the energy storage power supply is conducted, the rectified output of the power grid power supply is prevented, the boosting output of the energy storage power supply is applied to the input end of the inverter circuit and the input end of the switch power supply circuit, and the energy storage power supply provides electric energy for the voltage reduction inverter module.

In another specific control method of the present application, two paths of boost circuits are used to boost the energy storage power supply, and are respectively used to provide electric energy for the inverter circuit and the switching power supply circuit in the step-down inverter module. When the rectified voltage is smaller than the voltage set value, the switching circuit switches, the first boosting output and the second boosting output of the energy storage power supply are conducted, the rectified output of the power grid power supply is prevented, the first boosting output of the energy storage power supply is applied to the input end of the inverter circuit, the second boosting output is applied to the input end of the switching power supply circuit, and the energy storage power supply provides electric energy for the voltage reduction inverter module.

The voltage set value is lower than the rectified direct-current voltage after 220V alternating-current rectification, so that the power grid power supply is preferentially used when the power grid power supply is electrified.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.