Power supply module and electric welding machine

Abstract

The utility model relates to a power module and an electric welding machine. The power module comprises a conversion unit, a transformer, an adjusting unit and a first protection unit. The conversion unit is connected with the primary winding side of the transformer, and meanwhile the primary winding side of the transformer is further connected with the adjusting unit and the first protection unit. The first protection unit is arranged on the secondary winding side of the transformer, the output end of the first protection unit is connected with the electric welding machine shell, high-frequency interference on the primary winding side can be effectively filtered out through the connection mode, emergency treatment can be conveniently carried out during outdoor maintenance, and the power module outputs stable electric energy.

Description

Technical Field

[0001] This application relates to the field of switching power supply technology, and in particular to a power module and a welding machine. Background Technology

[0002] An electric welding machine is a device that converts electrical energy into heat energy and melts welding materials and base materials through a high-temperature electric arc to achieve metal-to-metal connection.

[0003] In traditional technology, a switching power supply is used to provide power to the welding machine. The power supply principle is that alternating current is rectified and then fed to the primary winding of a transformer. A switching transistor is also connected to the primary winding of the transformer. This transistor adjusts the change in the transformer's magnetic field, inducing a corresponding voltage on the secondary winding, thus supplying power to the welding machine. During the power supply process, high-frequency interference generated by the continuous switching of the transistor may cause the voltage Vds between the drain and source of the transistor to exceed the maximum drain voltage, leading to the transistor restarting and preventing the welding machine from operating normally.

[0004] Therefore, there is an urgent need for a power supply solution that can effectively eliminate high-frequency interference. Utility Model Content

[0005] Therefore, it is necessary to provide a power module and welding machine to address the problems mentioned above in the background technology, so as to solve the problem of high-frequency interference causing the switching transistor to restart in the prior art.

[0006] In a first aspect, this application provides a power module suitable for welding machines, comprising:

[0007] A conversion unit, whose input terminal is connected to an external AC power supply, is used to convert the AC power supply into DC power.

[0008] The transformer includes a primary winding side and a secondary winding side, and the primary winding side is connected to the output terminal of the conversion unit;

[0009] An adjustment unit, connected to the primary winding side, is used to adjust the magnetic field change of the transformer according to an externally input control signal, thereby inducing a corresponding voltage on the secondary winding side to supply power to the welding machine.

[0010] The first protection unit has its input end connected to the primary winding side and its output end connected to the outer casing of the welding machine, and is used to filter out high-frequency interference from the primary winding side.

[0011] In one embodiment, the first protection unit includes a Y capacitor, one end of which is connected to the primary winding side and the other end of which is connected to the housing of the welding machine.

[0012] In one embodiment, the conversion unit includes a rectifier bridge and a second protection unit;

[0013] The input terminal of the rectifier bridge is connected to the AC power supply, and the output terminal is connected to the primary winding side of the transformer.

[0014] The second protection unit is connected between the AC power supply and the input terminal of the rectifier bridge to prevent the rectifier bridge from being subjected to voltage surges.

[0015] In one embodiment, the rectifier bridge includes a first terminal and a second terminal; the second protection unit includes a first capacitor and a thermistor;

[0016] One end of the first capacitor is connected to one end of the AC power supply and the first end of the rectifier bridge, and the other end is connected to the second end of the rectifier bridge and one end of the thermistor.

[0017] The other end of the thermistor is connected to the other end of the AC power supply.

[0018] In one embodiment, the power module further includes a third protection unit;

[0019] The third protection unit is connected between the conversion unit and the transformer, and is used to filter out high-frequency interference from the transformer's front-end circuit.

[0020] In one embodiment, the third protection unit includes a plurality of capacitors connected in parallel.

[0021] In one embodiment, the power module further includes a filter capacitor for filtering the DC power converted by the conversion unit.

[0022] In one embodiment, the adjustment unit further includes a fourth protection unit;

[0023] The fourth protection unit is connected between the primary winding side of the transformer and the switching tube of the adjustment unit to reduce switching losses and suppress interference.

[0024] In one embodiment, the fourth protection unit includes a first diode, a second diode, a second capacitor, and a first resistor; the primary winding side of the transformer shown includes a first terminal and a second terminal;

[0025] The first diode and the second diode are connected in series in reverse, and the positive terminal of the first diode is connected to the first end of the primary winding side of the transformer, and the positive terminal of the second diode is connected to the switching transistor of the adjustment unit and the second end of the primary winding side of the transformer.

[0026] The second capacitor, the first resistor, and the first diode are connected in parallel.

[0027] Secondly, this application also provides a welding machine. The welding machine includes: a housing, and a power module as described in the first aspect;

[0028] The power module is located inside the housing and is used to provide power to the welding machine.

[0029] The aforementioned power module and welding machine have at least the following advantages:

[0030] The power module of this application includes a conversion unit, a transformer, an adjustment unit, and a first protection unit. The conversion unit is connected to the primary winding side of the transformer, and the primary winding side of the transformer is also connected to the adjustment unit and the first protection unit. This application provides a first protection unit on the secondary winding side of the transformer, and the output terminal of the first protection unit is connected to the welding machine casing. This connection method can effectively filter out high-frequency interference on the primary winding side, enabling emergency handling during off-site maintenance and ensuring stable power output from the power module. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the power module structure in one embodiment;

[0034] Figure 2 This is a schematic diagram of the conversion unit in one embodiment;

[0035] Figure 3 This is a schematic diagram of the power module in another embodiment;

[0036] Figure 4 This is a wiring diagram of the power module in another embodiment;

[0037] Figure 5 This is a schematic diagram of the structure of an electric welding machine in one embodiment. Detailed Implementation

[0038] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] When using the terms “including,” “having,” and “comprising” as described herein, another component may be added unless explicitly qualifying terms such as “only,” “consisting of,” etc. are used. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0041] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0042] In this application, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal connection of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0043] Please see Figure 1 In one feasible embodiment, this application provides a power module suitable for welding machines, including: a conversion unit, a transformer, an adjustment unit, and a first protection unit.

[0044] The conversion unit includes an input terminal and an output terminal. The input terminal of the conversion unit is connected to an external AC power source to convert the AC power into DC power. The output terminal of the conversion unit is connected to a transformer to supply DC power to the transformer as electrical energy.

[0045] A transformer includes a primary winding side and a secondary winding side, with the primary winding side connected to the output terminal of a conversion unit. The DC power output from this conversion unit serves as the input power for the transformer. The secondary winding side is connected to a welding machine to output the converted voltage. It should be understood that a transformer converts primary electrical energy into secondary electrical energy based on the principle of electromagnetic induction. The induced electromotive force in the primary winding side is related to the voltage and the turns ratio of the primary winding. By adjusting the turns ratio of the primary and secondary windings, the voltage can be increased or decreased. Furthermore, the transformer provides electrical isolation between the primary and secondary windings, ensuring electrical safety.

[0046] The adjustment unit, connected to the primary winding side, is used to adjust the magnetic field change of the transformer according to the externally input control signal, thereby inducing a corresponding voltage on the secondary winding side to supply power to the welding machine.

[0047] Specifically, the adjustment unit includes a high-voltage switching transistor. The externally input control signal is a PWM signal. By controlling the switching transistor to quickly turn on or off via the PWM signal, the magnetic field on the primary winding side changes, thereby inducing a corresponding AC voltage on the secondary winding side. This AC voltage is rectified into pulsating DC. Furthermore, the secondary winding side of the transformer also includes a filter circuit to filter the pulsating DC into a more stable DC for use by the welding machine.

[0048] For example, the adjustment unit in this embodiment uses a TOP246 chip, which integrates a high-voltage switching transistor connected to the primary winding of the transformer. By adjusting the switching frequency and duty cycle through pulse modulation (PWM), the magnetic field of the transformer is controlled, thereby inducing the required output voltage on the secondary winding side of the transformer.

[0049] The first protection unit has its input end connected to the primary winding side and its output end connected to the outer casing of the welding machine, and is used to filter out high-frequency interference from the primary winding side.

[0050] Specifically, in switching power supplies, the frequent switching operations of power switching devices, such as the high-voltage MOSFET inside the TOP246, and the high-frequency noise caused by the resonance of parasitic inductance / capacitance, generate high-frequency spike interference on the primary winding of the transformer. This causes the high-voltage switching transistor of the regulating unit to be affected by high frequency, and the voltage Vds between the drain and source exceeds the maximum drain voltage, resulting in the switching transistor restarting. Consequently, the output voltage of the transformer cannot maintain a stable state and cannot supply power normally.

[0051] The welding machine's casing is reliably connected to the ground, and the grounding wire uses a high-quality cable.

[0052] The aforementioned power module connects the primary winding to the welding machine's casing via the first protection unit, which can introduce high-frequency spike interference from the transformer's primary winding to the ground for emergency handling during off-site maintenance, and conveniently and quickly resolve the problem of the switching transistor restarting due to high-frequency interference.

[0053] Please see Figure 4 Optionally, the first protection unit includes a Y capacitor Y1, one end of which is connected to the primary winding side, and the other end is connected to the housing of the welding machine. The primary winding side includes a first end and a second end, and the first end of the primary winding side is connected to the Y capacitor.

[0054] It should be understood that Y capacitors are used to suppress common-mode interference. Placing a Y capacitor between the primary winding and the welding machine casing can guide this interference to ground. Furthermore, since the Y capacitor is connected to the ground wire, a small capacitance should be selected to limit leakage current through the ground wire; and high insulation performance should be chosen to avoid the risk of electric shock in the event of failure.

[0055] Please see Figure 2 Optionally, the conversion unit includes a rectifier bridge and a second protection unit.

[0056] Specifically, the rectifier bridge consists of four diodes in a bridge structure, each representing one arm of the rectifier bridge. The four diodes work together to achieve full-wave rectification.

[0057] A rectifier bridge includes a first terminal, a second terminal, a third terminal, and a fourth terminal. The first and second terminals constitute the input terminals of the rectifier bridge, while the third and fourth terminals constitute the output terminals. The input terminals of the rectifier bridge are connected to the alternating current, and the output terminals are connected to the primary winding of the transformer.

[0058] The second protection unit is connected between the AC power supply and the input terminal of the rectifier bridge to stabilize the output voltage of the rectifier bridge.

[0059] Please see Figure 4 Optionally, the second protection unit includes a first capacitor C1 and a thermistor TR1. Pin 1 of the rectifier bridge BD is the first terminal of the rectifier bridge, and pin 2 is the second terminal of the rectifier bridge. One end of the first capacitor C1 is connected to one end of the AC power supply and the first terminal of the rectifier bridge, and the other end is connected to the second terminal of the rectifier bridge BD and one end of the thermistor TR1; the other end of the thermistor TR1 is connected to the other end of the AC power supply.

[0060] In the aforementioned power module, the first capacitor C1 effectively filters out high-frequency noise that may be present in the AC power, preventing it from entering subsequent circuits. Furthermore, the first capacitor C1 can absorb spikes and transient changes in the AC power, protecting the rectifier bridge BD and subsequent circuits from high-voltage surges. Moreover, the first capacitor C1 can shorten the conduction time and reduce the conduction angle of the rectifier bridge, which helps reduce the heat loss of the rectifier diodes and improve the reliability of the power supply.

[0061] When the power is turned on, the first capacitor C1 charges instantaneously, generating a large inrush current. The thermistor TR1, with its high initial resistance, effectively limits this instantaneous inrush current, reducing the impact on the power supply circuit and subsequent components, extending component lifespan, and improving circuit reliability. Furthermore, the thermistor TR1 possesses self-recovery characteristics. Under overcurrent or overvoltage conditions, it enters a high-resistance state, but as the circuit returns to normal, its temperature drops, and the resistance returns to its normal level. This self-recovery characteristic allows the circuit to automatically resume normal operation after a short-term fault without requiring component replacement.

[0062] Please see Figure 3 Optionally, the power module may also include a third protection unit.

[0063] The third protection unit is connected between the conversion unit and the transformer and is used to filter out high-frequency interference from the transformer's front-end circuit.

[0064] Please see Figure 4 Optionally, the third protection unit includes multiple capacitors connected in parallel. For example, the third protection unit includes capacitors C3, C4, C5, and C6, wherein the capacitance of capacitor C3 is 102, or 10 × 10⁻⁶. 2 pF; the capacitance values ​​of capacitors C4, C5 and C6 are 103, 104 and 105 respectively.

[0065] The power module described above uses CBB capacitors in parallel. These capacitors have a small high-frequency loss angle and better high-frequency decoupling effect. Multiple capacitors with different capacitance values ​​connected in parallel can also better decouple and prevent high-frequency interference from the front-end power supply from coupling over.

[0066] Please see Figure 4 Optionally, the power supply module also includes a filter capacitor C2 for filtering the DC power converted by the conversion unit.

[0067] Specifically, the filter capacitor C2, through its charging and discharging action, converts the pulsating DC voltage output from the rectifier bridge into a smoother DC voltage, resulting in a smoother output voltage. Furthermore, the capacitor's short-circuit characteristic for high-frequency signals filters out high-frequency noise in the output signal, thereby improving power supply stability. Moreover, when the load changes or the power supply fluctuates, the filter capacitor C2 can release its stored energy to maintain stable circuit operation.

[0068] Please see Figure 3 Optionally, the adjustment unit may also include a fourth protection unit.

[0069] The fourth protection unit is connected between the primary winding side of the transformer and the switching transistor of the regulating unit to reduce switching losses and suppress interference. Furthermore, the primary winding side of the transformer includes a first terminal and a second terminal.

[0070] Please see Figure 4Optionally, the fourth protection unit includes a first diode D1, a second diode D2, a second capacitor C7, and a first resistor R1. The first diode D1 and the second diode D2 are connected in series in reverse, with the anode of the first diode D1 connected to the primary winding side of the transformer, and the anode of the second diode D2 connected to the switching transistor of the adjustment unit. The second capacitor C7 and the first resistor R1 are connected in parallel with the first diode D1. For example, taking the adjustment unit U1 using a TOP246 chip, the anode of the first diode D1 is connected to the first end of the primary winding side of the transformer, and the anode of the second diode D2 is connected to the second end of the primary winding side of the transformer and the drain of the switching transistor of the adjustment unit U1. In the above structure, the second capacitor C7 can be a fast recovery diode or a Schottky diode. The second capacitor C7, connected in parallel with the first resistor R1 and the first diode D1, serves to clamp and absorb voltage spikes. The second diode D2, connected in reverse, forms a complete clamping loop. Specifically, when a MOSFET is switched at high speed in a switching power supply, high-frequency voltage spikes (Vds) are generated between the MOSFET's drain and source due to the transformer's leakage inductance and parasitic inductance. A clamping circuit, using a reverse-connected diode and an RC network, limits these voltage spikes to a safe range, protecting the MOSFET from damage due to excessive voltage. When the MOSFET is turned off, the energy in the transformer's leakage inductance manifests as a voltage spike. The clamping circuit's capacitor temporarily stores this energy, which is then dissipated through a resistor, preventing interference from the spikes. Furthermore, if the voltage spike is too high during high-speed switching, it increases the MOSFET's turn-off losses. The aforementioned circuit absorbs these spikes, reducing turn-off losses and improving efficiency. Moreover, without a clamping circuit, high-frequency oscillations (ringing) may occur in the circuit when the leakage inductance releases energy due to parasitic inductance and capacitance. This structure effectively suppresses oscillations, reduces EMI, and improves the stability of the switching power supply.

[0071] The aforementioned power supply module connects the primary positive input circuit of the transformer to the ground of the welding machine casing via a Y capacitor. This removes high-frequency interference spikes from the high-frequency arcing on the switching transistors, and also eliminates electromagnetic interference from the power transistors, making the switching power supply more stable. Furthermore, the second protection unit between the AC power supply and the rectifier bridge absorbs spikes and transient changes in the AC power, protecting subsequent circuits from high-voltage surges. Further, the third protection unit at the transformer's front end filters out high-frequency interference from the transformer's front-end circuit. Further, the filter capacitor at the rectifier bridge's rear end filters the DC power converted by the conversion unit, improving power supply stability. Further, the fourth protection unit in the transformer's primary input circuit eliminates high-frequency voltage spikes, reduces turn-off losses, improves efficiency, and enhances the switching power supply's stability. The combined effect of these circuits enables the power supply module to provide a stable and reliable operating power supply to the load.

[0072] Based on the same inventive concept, this application also provides an electric welding machine, comprising:

[0073] The casing and the power module disclosed in the above embodiments. The power module is disposed inside the casing of the welding machine and is used to provide power to the welding machine.

[0074] The power module includes a conversion unit, a transformer, an adjustment unit, and a first protection unit.

[0075] The conversion unit has its input connected to an external AC power source to convert AC to DC. The output of the conversion unit is connected to a transformer, supplying DC power to the transformer as electrical energy.

[0076] The transformer includes a primary winding side and a secondary winding side, with the primary winding side connected to the output terminal of the conversion unit. The DC power output from the conversion unit serves as the input power for the transformer. The secondary winding side is connected to a welding machine and is used to output the converted voltage.

[0077] The adjustment unit, connected to the primary winding side, is used to adjust the magnetic field change of the transformer according to the externally input control signal, thereby inducing a corresponding voltage on the secondary winding side to supply power to the welding machine.

[0078] The first protection unit has its input end connected to the primary winding side and its output end connected to the outer casing of the welding machine, and is used to filter out high-frequency interference from the primary winding side.

[0079] The specific structure and working principle of the power module can be found in the above description of the power module; for the sake of brevity, they will not be repeated here.

[0080] It should be noted that the power module in the above embodiment is used in a welding machine as an example. In actual applications, the power module can also be used in other electrical equipment.

[0081] The aforementioned welding machine is powered by a power module, and the primary winding of the power module is connected to the welding machine's casing through a first protection unit. This design allows high-frequency spike interference from the transformer's primary winding to be grounded, enabling emergency handling during off-site maintenance and quickly resolving issues caused by high-frequency interference causing the switching transistor to restart.

[0082] Please note that the above embodiments are for illustrative purposes only and do not imply any limitation on the present invention.

[0083] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A power module suitable for use in a welding machine, characterized in that, include: A conversion unit, whose input terminal is connected to an external AC power supply, is used to convert the AC power supply into DC power. The transformer includes a primary winding side and a secondary winding side, and the primary winding side is connected to the output terminal of the conversion unit; An adjustment unit, connected to the primary winding side, is used to adjust the magnetic field change of the transformer according to an externally input control signal, thereby inducing a corresponding voltage on the secondary winding side to supply power to the welding machine. The first protection unit has its input end connected to the primary winding side and its output end connected to the outer casing of the welding machine, and is used to filter out high-frequency interference from the primary winding side.

2. The power module of claim 1, wherein, The first protection unit includes a Y capacitor, one end of which is connected to the primary winding side and the other end is connected to the outer casing of the welding machine.

3. The power module of claim 1, wherein, The conversion unit includes a rectifier bridge and a second protection unit; The input terminal of the rectifier bridge is connected to the AC power supply, and the output terminal is connected to the primary winding side of the transformer. The second protection unit is connected between the AC power supply and the input terminal of the rectifier bridge to prevent the rectifier bridge from being subjected to voltage surges.

4. The power module of claim 3, wherein, The rectifier bridge includes a first terminal and a second terminal; the second protection unit includes a first capacitor and a thermistor; One end of the first capacitor is connected to one end of the AC power supply and the first end of the rectifier bridge, and the other end is connected to the second end of the rectifier bridge and one end of the thermistor. The other end of the thermistor is connected to the other end of the AC power supply.

5. The power module of claim 1, wherein, The power module also includes a third protection unit; The third protection unit is connected between the conversion unit and the transformer, and is used to filter out high-frequency interference from the transformer's front-end circuit.

6. The power module of claim 5, wherein, The third protection unit includes multiple capacitors connected in parallel.

7. The power module of claim 1, wherein, The power module also includes a filter capacitor for filtering the DC power converted by the conversion unit.

8. The power module of claim 1, wherein, The adjustment unit also includes a fourth protection unit; The fourth protection unit is connected between the primary winding side of the transformer and the switching tube of the adjustment unit to reduce switching losses and suppress interference.

9. The power module of claim 8, wherein, The fourth protection unit includes a first diode, a second diode, a second capacitor, and a first resistor; the primary winding side of the transformer shown includes a first terminal and a second terminal; The first diode and the second diode are connected in series in reverse, and the positive terminal of the first diode is connected to the first end of the primary winding side of the transformer, and the positive terminal of the second diode is connected to the switching transistor of the adjustment unit and the second end of the primary winding side of the transformer. The second capacitor, the first resistor, and the first diode are connected in parallel.

10. An electric welder characterized by include: The housing, and the power module as described in any one of claims 1-9; The power module is located inside the housing and is used to provide power to the welding machine.

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