CN211889548U

CN211889548U - Double-voltage self-adaptive lithium electric welding machine

Info

Publication number: CN211889548U
Application number: CN202020243951.2U
Authority: CN
Inventors: 张广智; 范震
Original assignee: Nanjing Lijun New Energy Storage Research Institute Co ltd
Current assignee: Nanjing Lijun Power Technology Research Institute Co.,Ltd.
Priority date: 2020-03-03
Filing date: 2020-03-03
Publication date: 2020-11-10
Anticipated expiration: 2030-03-03

Abstract

A dual voltage adaptive lithium electric welder comprising: the voltage detection circuit outputs corresponding level signals according to different power supply voltages; the logic circuit is connected with the voltage detection circuit and outputs a corresponding control signal according to the received level signal; the power-on soft start circuit avoids damage of large impact current to a lithium battery at the moment of power-on, and comprises at least two chopping topological circuits which are respectively connected with output signals of a logic circuit, are complementarily arranged in phase and are used for fine control of welding current. The 96V power supply voltage and the 48V power supply voltage can be applied to the welding machine in a self-adaptive mode, the lithium battery selection range of the welding machine is expanded, the application range is wider, the double-circuit 48V series application is achieved, the endurance is increased, the output of the welding machine can be properly increased, and the welding operation effect is improved.

Description

Double-voltage self-adaptive lithium electric welding machine

Technical Field

The utility model relates to an industrial field's welding equipment specifically is a lithium electric welding machine of two voltage self-adaptations.

Background

The electric welding machine with the lithium battery as the power supply brings great convenience in welding operation construction in places where unpowered electricity (field construction) or power electricity connection is inconvenient, is flexible to move, does not need a power supply cable, does not have noise of the electric generator welding machine, and is popular with many users. The lithium electric welding machine applied to the market adopts more 48V power supply, can have longer duration and larger output by using 2 48V series battery packs, and is the lithium electric welding machine with both 96V power supply voltage and 48V power supply voltage applied, which is provided aiming at the problem.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides a lithium electric welding machine of two voltage self-adaptations adopts digital mode, through sampling lithium battery voltage, confirms battery voltage, and the control unit switches to the control procedure that corresponds, realizes corresponding control, include: the voltage detection circuit outputs corresponding levels when different voltages are supplied; the logic circuit is connected with the voltage detection circuit and outputs a control signal according to different programs operated by the received level signal; the soft start circuit is powered on to avoid damage to the lithium battery caused by large impact current at the moment of power on, and comprises a chopping topological circuit for fast and accurate control to obtain fine welding current.

Furthermore, the logic circuit comprises a programmable logic array chip and a microcontroller, wherein the programmable logic array chip is used for receiving signals and outputting a welding limiting maximum voltage signal after the signals are subjected to cooperative processing with the microcontroller.

Furthermore, the programmable logic array chip adopts an EP1C3T144 chip.

Further, the microcontroller adopts an STM32F407 chip.

Furthermore, the logic circuit comprises at least two driving circuits for adjusting the duty ratio of the corresponding maximum pulse width of the transistor according to different power supply voltages.

Furthermore, the input end of the driving circuit is connected with the logic circuit, and the output end of the driving circuit is connected with the chopping topology circuit, and the driving circuit comprises resistors R38, 23, 24, 25 and 26, an optocoupler U9, triodes Q7 and 8 and capacitors C7 and 16.

Further, the output end of the power-on soft start circuit is connected with a power supply structure of the chopper topology circuit, and the power supply structure comprises a relay K1, a resistor R27 and a diode V1.

Further, the chopper topology circuit completes output of working current and comprises resistors R1, R2, R3, a power tube Q1, a fast recovery diode D1 and an inductor L1.

The beneficial effects of the utility model are that, 96V and the equal ability self-adaptation welding machine of 48V two kinds of supply voltage have enlarged the lithium cell selection range of welding machine, and the range of application is wider, and double-circuit 48V establishes ties and uses, has increased continuation of the journey, and the welding machine is exerted oneself and also can suitably increase, has improved the welding operation efficiency.

Drawings

Fig. 1 is a schematic diagram of the medium voltage detection circuit of the present invention.

Fig. 2 is a schematic diagram of a logic circuit according to the present invention.

Fig. 3 is an enlarged view of the microcontroller in the logic circuit.

FIG. 4 is a schematic diagram of two sets of driving circuits in a logic circuit.

Fig. 5 is a schematic diagram of the middle power-on soft start circuit of the present invention.

Detailed Description

In order to clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other obvious modifications can be obtained without inventive efforts from these drawings.

The device detects the battery voltage through a voltage stabilizing diode and an optical coupler, the 96V power supply battery and the 48V power supply battery correspond to different signals and transmit the signals to a programmable logic array chip, and after the signals are cooperatively processed with other microcontrollers, a programmable logic array device outputs a signal for limiting the maximum welding voltage, so that the 96V and 48V power supply batteries can both output voltage ranges within requirements, and the current is ensured not to be instantaneously out of control. A soft start circuit is adopted in the power circuit, so that power-on impact is prevented, and instantaneous excessive current of the battery is prevented; the chopper topology circuit with two complementary paths can realize faster control and obtain finer welding current.

As shown in fig. 1, it is a schematic diagram of the medium voltage detection circuit of the present invention. The optocoupler N1, the voltage-regulator diode Z1(1N4759) and the resistor R1 form a lithium battery voltage detection circuit: when the power supply is a 48V battery, the voltage regulator tube Z1 is not conducted, and the output signal of the optocoupler N1 is at a low level; when the power supply is a 96V battery, the voltage regulator tube Z1 is conducted, and the output signal of the optocoupler N1 is at a high level.

As shown in fig. 2-4, which are schematic diagrams of the logic circuit of the present invention, the logic circuit includes a programmable logic array chip and a microcontroller, the programmable logic array chip is used for receiving signals, and outputs a maximum welding voltage limiting signal after being processed cooperatively with the microcontroller. A P31 pin of the logic array device U2 receives a level signal transmitted by the optocoupler N1, runs different programs according to the level of the received level signal, outputs a control signal to the 2-path optocouplers U8 and U9, and drives corresponding power devices.

It should be noted that the logic circuit includes a driving circuit, and when different voltages are supplied, the duty ratio of the corresponding maximum pulse width is adjusted, and the driving circuit is provided with two groups of driving units for driving the corresponding power devices. In the figure, resistors R38, R23, R24, R25 and R26, an optocoupler U9, triodes Q7 and Q8, capacitors C7 and C16 form a driving unit of a group of power tubes; resistors R39, R13, R14, R15 and R16, an optocoupler U8, triodes Q5 and Q6, capacitors C6 and C14 form a driving unit of another group of power tubes. The working voltage of the welding machine is within 40V, the duty ratio (D) of the maximum Pulse Width Modulation (PWM) can be 95% for a 48V power supply lithium battery, and the duty ratio (D) of the maximum Pulse Width Modulation (PWM) can be 45% for a 96V power supply lithium battery.

Preferably, the programmable logic array chip is an EP1C3T144 chip.

Preferably, the microcontroller is an STM32F407 chip.

As shown in fig. 5, it is a schematic diagram of the middle-upper power soft start circuit of the present invention. The relay K1, the resistor R27 and the diode V1 form a power-on soft start circuit, so that damage to a lithium battery caused by a large impact current at the power-on moment of a filter capacitor is avoided, and a battery system management (BMS) is protected.

It should be noted that the working principle of the power-on soft start circuit is as follows: when the relay K1 is electrified, the attraction contact is not switched off, the battery charges the capacitor C1 through the resistor R27, after the set time, the voltage of the capacitor C1 is close to the voltage of the battery, the contact is closed when the relay K1 is electrified, and the relay K1 can normally work without current impact. The delay time is controlled by the logic array device U2.

It should be noted that the chopper topology circuit has two paths, and the phases are complementary. In fig. 3, the resistors R1, R2, R3, the power transistor Q1, the fast recovery diode D1 and the inductor L1 form a chopper circuit, the symmetrical resistors R4, R5, R6, the power transistor Q2, the fast recovery diode D2 and the inductor L2 form another chopper circuit, the phases of the two chopper circuits are complementary, and the complementary driving signals are from the logic array device U2.

The utility model discloses do not adopt the relay, do not have mechanical motion part, the performance is more reliable and more stable. The 96V power supply voltage and the 48V power supply voltage can be applied to the welding machine in a self-adaptive mode, the lithium battery selection range of the welding machine is expanded, the application range is wider, the double-circuit 48V series application is achieved, the endurance is increased, the output of the welding machine can be properly increased, and the welding operation effect is improved.

Claims

1. A dual voltage adaptive lithium electric welder, comprising: the voltage detection circuit outputs corresponding level signals according to different power supply voltages; the logic circuit is connected with the voltage detection circuit and outputs a corresponding control signal according to the received level signal; the power-on soft start circuit avoids damage of large impact current to a lithium battery at the moment of power-on, and comprises at least two chopping topological circuits which are respectively connected with output signals of a logic circuit, are complementarily arranged in phase and are used for fine control of welding current.

2. A dual voltage adaptive lithium ion welder according to claim 1, wherein said logic circuit comprises a programmable logic array chip and a microcontroller, said programmable logic array chip configured to receive signals and, after cooperating with said microcontroller, configured to limit maximum welding voltage signal output.

3. A dual voltage adaptive lithium ion welder according to claim 2, wherein said programmable logic array chip is EP1C3T 144.

4. A lithium electric welder as recited in claim 2, characterized in that STM32F407 chip is selected as said microcontroller.

5. A dual voltage adaptive lithium ion welder according to claim 1, wherein said logic circuit comprises at least two driver circuits for adjusting duty cycles of respective maximum pulse widths of the transistors for different supply voltages.

6. A double-voltage self-adaptive lithium ion welding machine according to claim 5, wherein the input end of the driving circuit is connected with the logic circuit, and the output end of the driving circuit is connected with the chopping topology circuit, and the double-voltage self-adaptive lithium ion welding machine comprises resistors R38, 23, 24, 25 and 26, an optical coupler U9, a triode Q7 and 8 and capacitors C7 and 16.

7. A lithium electric welder as recited in claim 1, wherein the output of said soft start circuit is connected to the power supply structure of said chopper topology, comprising relay K1, resistor R27, and diode V1.

8. A lithium-ion welding machine with double voltage self-adaption as claimed in claim 1, wherein the chopper topology circuit completes output of working current and comprises resistors R1, R2, R3, power tube Q1, fast recovery diode D1 and inductor L1.