Multi-mode electric resistance welding power source, control method, terminal and storage medium

Abstract

The invention provides a multi-mode resistance welding power source, a control method, a terminal and a storage medium. According to the method, a phase-shifted full-bridge circuit, a rectifying circuit, a modal control circuit and an inverter circuit which are connected in sequence are included; the phase-shifted full-bridge circuit is used for converting direct current of the direct-current power supply into alternating current and carrying out voltage reduction; the rectifying circuit is used for converting the alternating current after voltage reduction into direct current after voltage reduction; the modal control circuit is used for outputting the voltage-reduced direct current at a constant voltage in a constant voltage mode and outputting the voltage-reduced direct current at a constant current in a constant current mode; and the inverter circuit is used for converting the voltage-reduced direct current into alternating current pulse and outputting the alternating current pulse. According to the invention, output of high-power harmonic-free oscillation-free constant-voltage / constant-current positive-polarity, negative-polarity and bipolar pulses can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resistance welding, and in particular to a multi-modal resistance welding power supply, a control method, a terminal and a storage medium. BACKGROUND

[0002] As an important welding method, resistance welding has been widely used in industrial production due to its high production efficiency and good welding quality. The resistance welding power supply is an important part of the resistance welding machine and has a significant impact on the welding quality.

[0003] The core requirement of the resistance welding power supply is large current and low voltage output. At the same time, different welding processes and materials require the power supply to have constant voltage or constant current modes. The constant voltage mode can reduce the electrode impact force and prolong the life of the welding head. The constant current mode is required for semiconductor devices and thin plate welding to avoid splashing or insufficient penetration caused by current fluctuations.

[0004] At present, resistance welding power supplies include single-phase power frequency AC power supplies, capacitor energy storage power supplies, and high-frequency inverter pulse power supplies. However, these power supplies only have single output modes of constant voltage output or constant current output, making it difficult to adapt to resistance welding requirements in complex scenarios. SUMMARY

[0005] Embodiments of the present application provide a multi-modal resistance welding power supply, a control method, a terminal and a storage medium to solve the problem that current resistance welding power supplies only have single output modes.

[0006] In a first aspect, embodiments of the present application provide a multi-modal resistance welding power supply, comprising a phase-shifted full-bridge circuit, a rectifier circuit, a mode control circuit and an inverter circuit connected in sequence;

[0007] The phase-shifted full-bridge circuit is used to convert the direct current of the direct current power supply into alternating current and step down;

[0008] The rectifier circuit is used to convert the stepped-down alternating current into stepped-down direct current;

[0009] The mode control circuit is used to output the stepped-down direct current at a constant voltage in constant voltage mode and output the stepped-down direct current at a constant current in constant current mode;

[0010] The inverter circuit is used to convert the stepped-down direct current into alternating current pulses and output.

[0011] In one possible implementation, the mode control circuit includes an inductor, a capacitor, a first switch branch and a second switch branch;

[0012] The first end of the inductor constitutes the high-voltage input end of the mode control circuit, and the second end constitutes the high-voltage output end of the mode control circuit;

[0013] The positive electrode of the capacitor is connected with the first end of the inductor through the first switch branch and connected with the second end of the inductor through the second switch branch, and the negative electrode is used as the low-voltage input end and the low-voltage output end of the mode control circuit.

[0014] The mode control circuit is specifically configured to work in the constant-voltage mode when the first switch branch is disconnected and the second switch branch is turned on.

[0015] In a possible implementation, the mode control circuit is specifically configured to work in the constant-current mode when the first switch branch is turned on and the second switch branch is disconnected.

[0016] In a possible implementation, the first switch branch includes a first diode and a first switch tube, and the second switch branch includes a second switch tube and a third switch tube.

[0017] The drain electrode of the first switch tube is connected with the positive electrode of the capacitor, the source electrode is connected with the positive electrode of the first diode, the negative electrode of the first diode is connected with the first end of the inductor, the drain electrode of the second switch tube is connected with the positive electrode of the capacitor, the source electrode is connected with the source electrode of the third switch tube, and the drain electrode of the third switch tube is connected with the positive electrode of the capacitor.

[0018] The mode control circuit is specifically configured to work in the constant-current mode when the duty cycle of the inverter circuit is greater than or equal to 0.5, the first switch tube is turned on, and the second switch tube and the third switch tube are disconnected.

[0019] In a possible implementation, the inverter circuit includes a fourth switch tube, a fifth switch tube, a sixth switch tube and a seventh switch tube.

[0020] The drain electrode of the fourth switch tube is connected with the drain electrode of the sixth switch tube and constitutes the high-voltage input end of the inverter circuit, the source electrode of the fifth switch tube is connected with the source electrode of the seventh switch tube and constitutes the low-voltage input end of the inverter circuit, the source electrode of the fourth switch tube is connected with the drain electrode of the fifth switch tube and constitutes the first output end of the multi-mode resistance welding power supply, and the source electrode of the sixth switch tube is connected with the drain electrode of the seventh switch tube and constitutes the second output end of the multi-mode resistance welding power supply.

[0021] The inverter circuit is specifically configured to convert the stepped-down direct current into a positive polarity alternating current pulse and output when the fourth switch tube and the seventh switch tube are turned on and the fifth switch tube and the sixth switch tube are disconnected.

[0022] The inverter circuit is specifically configured to convert the stepped-down direct current into a negative polarity alternating current pulse and output when the fourth switch tube and the seventh switch tube are disconnected and the fifth switch tube and the sixth switch tube are turned on.

[0023] The inverter circuit is specifically configured to convert the stepped-down direct current into a bipolar alternating current pulse and output when the fourth switch tube and the seventh switch tube, the fifth switch tube and the sixth switch tube are alternately disconnected and turned on.

[0024] In a possible implementation, the mode control circuit is specifically configured to operate in the constant current mode when the duty cycle of the inverter circuit is less than 0.5, the fourth switch tube and the sixth switch tube are turned off, and the third switch tube is turned on.

[0025] In a possible implementation, the phase-shift full-bridge circuit includes a transformer, an eighth switch tube, a ninth switch tube, a tenth switch tube, and an eleventh switch tube, and the rectifier circuit includes a second diode, a third diode, a fourth diode, and a fifth diode.

[0026] The drain of the eighth switch tube and the tenth switch tube are connected and constitute a high-voltage input end of the phase-shift full-bridge circuit, the source of the ninth switch tube and the eleventh switch tube are connected and constitute a low-voltage input end of the phase-shift full-bridge circuit, the source of the eighth switch tube and the drain of the ninth switch tube are connected to an anode end of a primary side of the transformer, and the source of the tenth switch tube and the drain of the eleventh switch tube are connected to a cathode end of the primary side of the transformer.

[0027] The anode end of the secondary side of the transformer is connected to the anode of the second diode and the cathode of the third diode, the cathode end of the secondary side of the transformer is connected to the anode of the fourth diode and the cathode of the fifth diode, the cathode of the second diode is connected to the cathode of the fourth diode, and the cathode of the third diode is connected to the cathode of the fifth diode, thereby constituting a high-voltage output end of the rectifier circuit and a low-voltage output end of the rectifier circuit.

[0028] In a second aspect, an embodiment of the present application provides a control method of a multi-modal resistance welding power supply, the multi-modal resistance welding power supply including a phase-shift full-bridge circuit, a rectifier circuit, a mode control circuit, and an inverter circuit connected in sequence; and the method includes:

[0029] The phase-shift full-bridge circuit converts direct current of a direct current power supply into alternating current and performs voltage reduction;

[0030] The rectifier circuit converts the reduced voltage alternating current into reduced voltage direct current;

[0031] The mode control circuit outputs the reduced voltage direct current at a constant voltage in a constant voltage mode and outputs the reduced voltage direct current at a constant current in a constant current mode;

[0032] The inverter circuit converts the reduced voltage direct current into alternating current pulses and outputs the alternating current pulses.

[0033] In a third aspect, an embodiment of the present application provides a terminal including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the method according to the first aspect or any possible implementation of the first aspect when executing the computer program.

[0034] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, which stores a computer program. The computer program is executed by a processor to implement the steps of the method in the first aspect or any possible implementation manner of the first aspect.

[0035] The embodiment of the present application provides a multi-modal resistance welding power supply, a control method, a terminal and a storage medium. The direct current of a direct current power supply is stepped down through a phase-shift full-bridge circuit and a rectifier circuit, constant voltage and constant current output are realized through a mode control circuit, the direct current is inverted into positive polarity, negative polarity and bipolar pulse output through an inverter circuit, large-power harmonic-free and oscillation-free constant voltage / constant current positive polarity, negative polarity and bipolar pulse output are realized, a plurality of working modes are provided, and the resistance welding demand in a complex scene can be met. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0037] Figure 1 is a structural schematic diagram of a multi-modal resistance welding power supply provided by an embodiment of the present application;

[0038] Figure 2 is a circuit structural diagram of a multi-modal resistance welding power supply provided by an embodiment of the present application;

[0039] Figure 3 is an equivalent circuit diagram of a multi-modal resistance welding power supply provided by an embodiment of the present application in a constant voltage output mode;

[0040] Figure 4 is a current trend diagram of a multi-modal resistance welding power supply provided by an embodiment of the present application when working in a constant current mode;

[0041] Figure 5A is a current trend diagram of an inverter circuit in a positive polarity pulse output mode provided by an embodiment of the present application;

[0042] Figure 5B is a current trend diagram of an inverter circuit in a negative polarity pulse output mode provided by an embodiment of the present application;

[0043] Figure 6 is a current trend diagram of a capacitor charging process provided by an embodiment of the present application;

[0044] Figure 7 is a current trend diagram of a capacitor discharging process provided by an embodiment of the present application;

[0045] Figure 8 is an implementation flowchart of a control method of a multi-modal resistance welding power supply provided by an embodiment of the present application;

[0046] Figure 9 is a schematic diagram of a terminal provided by an embodiment of the present application. DETAILED DESCRIPTION

[0047] In the following description, specific details are set forth, such as particular system configurations, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. However, persons skilled in the art will understand that the present application can be practiced without these specific details. In other instances, well-known structures, devices, circuits, and methods have not been described in detail in order to avoid obscuring the present application.

[0048] In order to make the objects, technical solutions and advantages of the present application clearer, the following will be described by specific embodiments in conjunction with the accompanying drawings.

[0049] Referring to Figure 1 , which shows a structural schematic diagram of a multi-modal resistance welding power supply provided by an embodiment of the present application, the multi-modal resistance welding power supply comprises a phase-shifted full-bridge circuit 11, a rectifier circuit 12, a modal control circuit 13 and an inverter circuit 14 connected in sequence.

[0050] The phase-shifted full-bridge circuit 11 is configured to convert direct current of a direct current power supply into alternating current and perform voltage reduction.

[0051] The rectifier circuit 12 is configured to convert the voltage-reduced alternating current into voltage-reduced direct current.

[0052] The modal control circuit 13 is configured to output the voltage-reduced direct current at a constant voltage in a constant voltage mode and output the voltage-reduced direct current at a constant current in a constant current mode.

[0053] The inverter circuit 14 is configured to convert the voltage-reduced direct current into alternating current pulses and output.

[0054] In the present embodiment, the earliest resistance welding power supply is a non-synchronous single-phase power frequency resistance welding machine, which has simple structure, convenient operation and low price. However, it has the following disadvantages: 1. Single-phase power supply is adopted, which will cause great impact on the power grid during use; 2. The power factor is low, usually about 0.2-0.7, and the power factor will be further reduced with the increase of the secondary circuit; 3. Thyristor control is adopted, the maximum control frequency is 10 Hz, which leads to slow control speed and low control precision.

[0055] The capacitor energy storage welding machine uses a special electrolytic capacitor as an energy storage element, has the characteristics of large output transient current and short welding time, but the current output overshoot is large, uncontrollable, and prone to problems such as spatter and workpiece burning.

[0056] The three-phase low-frequency resistance welding machine adopts three-phase power supply to avoid three-phase imbalance of the power grid, and the low-frequency output significantly reduces the loop inductance, and the power factor can reach more than 0.85. The current waveform of slow rise and slow fall reduces metal spatter and stabilizes the welding process. The main disadvantages are high equipment cost, large size, and long low-frequency commutation period. The high-frequency inverter pulse power has an electric conversion efficiency of more than 90%, the high frequency reduces the size of the transformer, and the light weight, fast dynamic response speed, fast and smooth output current, and accurate stability time control characteristics make it the development trend of resistance welding power supply.

[0057] In view of the problems of poor dynamic load adaptability and waveform distortion of the low-frequency single-polarity pulse power supply, the embodiment provides a multi-modal constant-current / constant-voltage high-frequency large-power pulse power supply device. Through the sequentially connected phase-shifted full-bridge circuit 11, rectifier circuit 12, mode control circuit 13 and inverter circuit 14, the switchable constant-voltage and constant-current dual-mode can be realized by combining the control strategy. At the same time, the constant-voltage mode can realize output of large-power, non-harmonic and non-oscillation constant-voltage positive polarity, negative polarity and bipolarity pulse, and the constant-current mode can realize output of large-power, non-harmonic and non-oscillation constant-current positive polarity, negative polarity and bipolarity pulse, thereby solving the problem of single output mode of only constant-voltage output or constant-current output of the existing power supply.

[0058] The embodiment of the present application reduces the voltage of the direct current of the direct current power supply through the phase-shifted full-bridge circuit and the rectifier circuit, realizes the output of constant voltage and constant current through the mode control circuit, and inverts the direct current into positive polarity, negative polarity and bipolarity pulse output through the inverter circuit. The output of large-power, non-harmonic and non-oscillation constant-voltage / constant-current positive polarity, negative polarity and bipolarity pulse is realized, and a plurality of working modes are provided, which can meet the resistance welding demand in complex scenes.

[0059] In a possible implementation manner, the mode control circuit comprises an inductor, a capacitor, a first switch branch and a second switch branch.

[0060] The first end of the inductor constitutes a high-voltage input end of the mode control circuit, and the second end constitutes a high-voltage output end of the mode control circuit.

[0061] The positive pole of the capacitor is connected with the first end of the inductor through the first switch branch and connected with the second end of the inductor through the second switch branch, and the negative pole serves as a low-voltage input end and a low-voltage output end of the mode control circuit.

[0062] The mode control circuit is specifically used for working in the constant-voltage mode when the first switch branch is disconnected and the second switch branch is turned on.

[0063] In the embodiment, the specific circuit structure of the multi-modal resistance welding power supply is as shown in Figure 2 The mode control circuit includes a first switch branch composed of inductor L1, capacitor C1, switch tube S5 and diode D5, a second switch branch composed of switch tube S6 and switch tube S7, and controls the on-off of the first switch branch and the second switch branch to realize the constant voltage and constant current mode switching of the power supply. The welding gun is connected between switch tube S8, switch tube S9, switch tube S10 and switch tube S11, and the positive polarity, negative polarity and bipolar pulse output mode switching can be realized by controlling switch tube S8, switch tube S9, switch tube S10 and switch tube S11.

[0064] Specifically, the equivalent circuit of the multi-modal resistance welding power supply in the constant voltage output mode is as shown in Figure 3 At this time, switch tube S5 is turned off, switch tube S6 and switch tube S7 are turned on, inductor L1 and capacitor C1 are in series resonance, which is equivalent to a wire, and the voltage source is equivalent to the voltage across the capacitor, so that the circuit can perform constant voltage output.

[0065] In a possible implementation, the mode control circuit is specifically configured to work in the constant current mode when the first switch branch is turned on and the second switch branch is turned off.

[0066] In the embodiment, the current trend of the mode control circuit working in the constant current mode is as shown in Figure 4 The first switch branch is turned on and the second switch branch is turned off at this time, and the secondary side current enters the inverter circuit through inductor L1, which is equivalent to a current source, so that the circuit performs constant current output.

[0067] In a possible implementation, the first switch branch includes a first diode and a first switch tube, and the second switch branch includes a second switch tube and a third switch tube.

[0068] The drain electrode of the first switch tube is connected with the positive electrode of the capacitor, the source electrode is connected with the positive electrode of the first diode, the negative electrode of the first diode is connected with the first end of the inductor, the drain electrode of the second switch tube is connected with the positive electrode of the capacitor, the source electrode is connected with the source electrode of the third switch tube, and the drain electrode of the third switch tube is connected with the positive electrode of the capacitor.

[0069] The mode control circuit is specifically configured to work in the constant current mode when the duty cycle of the inverter circuit is greater than or equal to 0.5, the first switch tube is turned on, and the second switch tube and the third switch tube are turned off.

[0070] In the embodiment, the constant current output mode is divided into two cases of large duty cycle and small duty cycle. In the constant current output mode, the duty cycle is usually greater than 0.5 to ensure that the circuit can sustain the current. When the duty cycle of the inverter circuit module is greater than or equal to 0.5 and less than or equal to 0.8, the first switch tube S5 is turned on, and the second switch tube S6 and the third switch tube S7 are turned off, so that the mode control circuit works in the constant current mode.

[0071] In a possible implementation, the inverter circuit comprises a fourth switch tube, a fifth switch tube, a sixth switch tube and a seventh switch tube;

[0072] The drain electrode of the fourth switch tube is connected with the drain electrode of the sixth switch tube, and constitutes a high-voltage input end of the inverter circuit. The source electrode of the fifth switch tube is connected with the source electrode of the seventh switch tube, and constitutes a low-voltage input end of the inverter circuit. The source electrode of the fourth switch tube is connected with the drain electrode of the fifth switch tube, and constitutes a first output end of the multi-mode resistance welding power supply. The source electrode of the sixth switch tube is connected with the drain electrode of the seventh switch tube, and constitutes a second output end of the multi-mode resistance welding power supply.

[0073] The inverter circuit, specifically for converting the stepped-down direct current into a positive polarity alternating current pulse and outputting when the fourth switch tube and the seventh switch tube are turned on and the fifth switch tube and the sixth switch tube are turned off,

[0074] The inverter circuit, specifically for converting the stepped-down direct current into a negative polarity alternating current pulse and outputting when the fourth switch tube and the seventh switch tube are turned off and the fifth switch tube and the sixth switch tube are turned on,

[0075] The inverter circuit, specifically for converting the stepped-down direct current into a bipolar alternating current pulse and outputting when the fourth switch tube and the seventh switch tube and the fifth switch tube and the sixth switch tube are turned on and off alternately.

[0076] In the embodiment, by controlling the on-off of the fourth switch tube S8, the fifth switch tube S9, the sixth switch tube S10 and the seventh switch tube S11, positive polarity, negative polarity and bipolar pulse output can be realized. The specific control mode is as follows:

[0077] Positive polarity pulse output: the switch tube S8 and the switch tube S11 are turned on, and the switch tube S9 and the switch tube S11 are turned off, as shown in FIG. 5, the current flows from left to right through the welding gun. Figure 5A

[0078] Negative polarity pulse output: the switch tube S9 and the switch tube S10 are turned on, and the switch tube S8 and the switch tube S10 are turned off, as shown in FIG. 6, the current flows from right to left through the welding gun. Figure 5B

[0079] Bipolar pulse output: the switch tube S8 and the switch tube S11 form a group, and the switch tube S9 and the switch tube S11 form a group, and the two groups of switch tubes are controlled to be turned on alternately to realize bipolar pulse output.​​

[0080] In a possible implementation, the mode control circuit is specifically configured to operate in the constant current mode when the duty cycle of the inverter circuit is less than 0.5, the fourth switch tube and the sixth switch tube are turned off, and the third switch tube is turned on.

[0081] In this embodiment, when the duty cycle is small, the duty cycle of the inverter circuit module is greater than or equal to 0.2 and less than 0.5, and the output current pulse range is increased by controlling the small duty cycle.

[0082] The capacitor charging process is as shown in Figure 6 When the switch tubes S8 and S10 are turned off at the same time, the switch tube S7 is turned on, the current flows through the body diode of the switch tube S7 and the switch tube S6, and the capacitor C1 is charged. Figure 7 The capacitor discharging process is as shown in

[0083] When the duty cycle is less than 0.5, all the four switch tubes on the inverter side are turned off. Since the inductance current cannot be suddenly changed, in order to maintain the original current, a very high voltage is generated across the inductance, which acts on the switch tube and can break through the switch device, burn the element insulation, and generate electromagnetic interference. At the same time, the switch tube device will bear a large current stress, heat increase, affect the service life and stability, increase the loss and reduce the efficiency. Therefore, the switch tube S7 is added to provide a freewheeling circuit when all the switch tubes on the inverter side are turned off.

[0084] In a possible implementation, the phase-shifted full-bridge circuit includes an eighth switch tube, a ninth switch tube, a tenth switch tube, and an eleventh switch tube, and the rectifier circuit includes a second diode, a third diode, a fourth diode, and a fifth diode.

[0085] The drain of the eighth switch tube and the tenth switch tube are connected and constitute a high-voltage input end of the phase-shifted full-bridge circuit, the source of the ninth switch tube and the eleventh switch tube are connected and constitute a low-voltage input end of the phase-shifted full-bridge circuit, the source of the eighth switch tube and the drain of the ninth switch tube are connected to the same end of the primary side of the transformer, and the source of the tenth switch tube and the drain of the eleventh switch tube are connected to the different end of the primary side of the transformer.

[0086] The same end of the secondary side of the transformer is connected to the positive electrode of the second diode and the negative electrode of the third diode, the different end of the secondary side of the transformer is connected to the positive electrode of the fourth diode and the negative electrode of the fifth diode, the negative electrode of the second diode is connected to the negative electrode of the fourth diode, and constitutes a high-voltage output end of the rectifier circuit, and the negative electrode of the third diode is connected to the negative electrode of the fifth diode, and constitutes a low-voltage output end of the rectifier circuit.

[0087] In this embodiment, as shown in Figure 2As shown, the drain of the eighth switch tube S1 and the tenth switch tube S3 are connected, and constitute the high-voltage input end of the phase-shifted full-bridge circuit, for being connected with the positive pole of the direct-current power supply, and the source of the ninth switch tube S2 and the eleventh switch tube S4 are connected, and constitute the low-voltage input end of the phase-shifted full-bridge circuit, for being connected with the negative pole of the direct-current power supply.

[0088] The same name end of the secondary side of the transformer T1 is connected with the positive pole of the second diode D1 and the negative pole of the third diode D2, and the different name end of the secondary side of the transformer T1 is connected with the positive pole of the fourth diode D3 and the negative pole of the fifth diode D4, the negative pole of the second diode D1 is connected with the negative pole of the fourth diode D3, and constitutes the high-voltage output end of the rectifier circuit, and the negative pole of the third diode D2 is connected with the negative pole of the fifth diode D4, and constitutes the low-voltage output end of the rectifier circuit.

[0089] It can be known from the above that the multi-modal resistance welding power supply provided by the embodiment of the application can realize switching constant voltage and constant current double modes, and the constant voltage mode can realize output of large-power, non-harmonic, non-oscillation, constant-voltage, positive polarity, negative polarity and double polarity pulses, and the cross current mode can realize output of large-power, non-harmonic, non-oscillation, constant-current, positive polarity, negative polarity and double polarity pulses. Compared with a single-phase power frequency resistance welding machine, the heat input of the application is precisely controllable, the power factor is above 0.95, and the application is high in energy efficiency and friendly to the power grid; compared with a capacitor energy storage welding machine, the application is high in energy utilization rate and flexible in dynamic response and process; compared with a three-phase low-frequency resistance welding machine, the application is reduced in size by more than 50%, and the response speed reaches the microsecond level, and the high-frequency double polarity is suitable for multiple scene modes such as electric welding, seam welding and projection welding.

[0090] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the application.

[0091] The following is the device embodiment of the application, and for the details not described in detail, reference can be made to the corresponding method embodiments described above.

[0092] Figure 8 The implementation flowchart of the control method of the multi-modal resistance welding power supply provided by the embodiment of the application is shown, only the part related to the embodiment of the application is shown for the convenience of description, and the details are described as follows:

[0093] The multi-modal resistance welding power supply includes a phase-shifted full-bridge circuit, a rectifier circuit, a mode control circuit and an inverter circuit connected in sequence; the method includes:

[0094] The phase-shift full-bridge circuit converts the direct current of the direct current power supply into alternating current and performs voltage reduction in step 801.

[0095] The rectifier circuit converts the reduced alternating current into reduced direct current in step 802.

[0096] The mode control circuit outputs the reduced direct current at a constant voltage in the constant voltage mode and outputs the reduced direct current at a constant current in the constant current mode in step 803.

[0097] The inverter circuit converts the reduced direct current into alternating current pulses and outputs the alternating current pulses in step 804.

[0098] In a possible implementation, the mode control circuit includes an inductor, a capacitor, a first switch branch, and a second switch branch.

[0099] The first end of the inductor constitutes a high-voltage input end of the mode control circuit, and the second end constitutes a high-voltage output end of the mode control circuit.

[0100] The positive pole of the capacitor is connected to the first end of the inductor through the first switch branch and connected to the second end of the inductor through the second switch branch, and the negative pole serves as a low-voltage input end and a low-voltage output end of the mode control circuit.

[0101] Step 803 includes:

[0102] The mode control circuit works in the constant voltage mode when the first switch branch is disconnected and the second switch branch is turned on.

[0103] In a possible implementation, step 803 includes:

[0104] The mode control circuit works in the constant current mode when the first switch branch is turned on and the second switch branch is disconnected.

[0105] In a possible implementation, the first switch branch includes a first diode and a first switch tube, and the second switch branch includes a second switch tube and a third switch tube.

[0106] The drain of the first switch tube is connected to the positive pole of the capacitor, the source is connected to the positive pole of the first diode, the negative pole of the first diode is connected to the first end of the inductor, the drain of the second switch tube is connected to the positive pole of the capacitor, the source is connected to the source of the third switch tube, and the drain of the third switch tube is connected to the positive pole of the capacitor.

[0107] Step 803 includes:

[0108] The mode control circuit works in the constant current mode when the duty cycle of the inverter circuit is greater than or equal to 0.5, the first switch tube is turned on, and the second switch tube and the third switch tube are disconnected.

[0109] In a possible implementation, the inverter circuit comprises a fourth switch tube, a fifth switch tube, a sixth switch tube and a seventh switch tube.

[0110] The drain of the fourth switch tube is connected with the drain of the sixth switch tube, and constitutes a high-voltage input end of the inverter circuit; the source of the fifth switch tube is connected with the source of the seventh switch tube, and constitutes a low-voltage input end of the inverter circuit; the source of the fourth switch tube is connected with the drain of the fifth switch tube, and constitutes a first output end of the multi-modal resistance welding power supply; and the source of the sixth switch tube is connected with the drain of the seventh switch tube, and constitutes a second output end of the multi-modal resistance welding power supply.

[0111] Step 804 comprises:

[0112] When the fourth switch tube and the seventh switch tube are turned on, and the fifth switch tube and the sixth switch tube are turned off, the inverter circuit converts the DC voltage after voltage reduction into positive polarity AC pulses and outputs,

[0113] When the fourth switch tube and the seventh switch tube are turned off, and the fifth switch tube and the sixth switch tube are turned on, the inverter circuit converts the DC voltage after voltage reduction into negative polarity AC pulses and outputs,

[0114] When the fourth switch tube and the seventh switch tube, the fifth switch tube and the sixth switch tube are alternately turned on and turned off, the inverter circuit converts the DC voltage after voltage reduction into bipolar AC pulses and outputs.

[0115] In a possible implementation, step 803 comprises:

[0116] When the duty cycle of the inverter circuit is less than 0.5, the fourth switch tube and the sixth switch tube are turned off, and the third switch tube is turned on, the mode control circuit works in the constant current mode.

[0117] In a possible implementation, the phase-shifted full-bridge circuit comprises an eighth switch tube, a ninth switch tube, a tenth switch tube and an eleventh switch tube, and the rectifier circuit comprises a second diode, a third diode, a fourth diode and a fifth diode.

[0118] The drains of the eighth switch tube and the tenth switch tube are connected, and constitute a high-voltage input end of the phase-shifted full-bridge circuit; the sources of the ninth switch tube and the eleventh switch tube are connected, and constitute a low-voltage input end of the phase-shifted full-bridge circuit; the source of the eighth switch tube and the drain of the ninth switch tube are connected with the same-named end of the primary side of the transformer; and the source of the tenth switch tube and the drain of the eleventh switch tube are connected with the different-named end of the primary side of the transformer.

[0119] The same name end of the secondary side of the transformer is connected with the positive pole of the second diode and the negative pole of the third diode, the different name end of the secondary side of the transformer is connected with the positive pole of the fourth diode and the negative pole of the fifth diode, the negative pole of the second diode is connected with the negative pole of the fourth diode and forms a high-voltage output end of the rectifier circuit, and the negative pole of the third diode is connected with the negative pole of the fifth diode and forms a low-voltage output end of the rectifier circuit.

[0120] The embodiment of the present application reduces the direct current of the direct current power supply through the phase-shift full-bridge circuit and the rectifier circuit, realizes constant voltage and constant current output through the modal control circuit, inverts the direct current into positive polarity, negative polarity and bipolar pulse output through the inverter circuit, realizes output of high-power, harmonic-free and oscillation-free constant voltage / constant current positive polarity, negative polarity and bipolar pulse, has multiple working modes, and can meet the resistance welding demand in complex scenes.

[0121] Figure 9 is a schematic diagram of a terminal provided by the embodiment of the present application. Figure 9 As shown in the figure, the terminal 9 of the embodiment includes a processor 90, a memory 91, and a computer program 92 stored in the memory 91 and executable on the processor 90. The processor 90 implements the steps in the control method embodiments of the various multi-modal resistance welding power supplies described above when executing the computer program 92, such as Figure 8 Steps 801 to 804 shown in the figure.

[0122] For example, the computer program 92 can be divided into one or more modules / units, which are stored in the memory 91 and executed by the processor 90 to complete the present application. The one or more modules / units can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program 92 in the terminal 9.

[0123] The terminal 9 can be a desktop computer, a notebook computer, a palm computer, a cloud server, and other computing devices. The terminal 9 can include, but is not limited to, the processor 90 and the memory 91. Those skilled in the art can understand, Figure 9 is merely an example of the terminal 9 and does not constitute a limitation on the terminal 9, and can include more or fewer components than shown, or combine certain components, or different components, for example, the terminal can also include an input / output device, a network access device, a bus, etc.

[0124] The processor 90 can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0125] The memory 91 can be an internal storage unit of the terminal 9, such as a hard disk or a memory of the terminal 9. The memory 91 can also be an external storage device of the terminal 9, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 91 can include both the internal storage unit and the external storage device of the terminal 9. The memory 91 is used to store the computer program and other programs and data required by the terminal. The memory 91 can also be used to temporarily store data that has been output or is to be output.

[0126] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is exemplified, and in actual application, the above functions can be completed 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 complete all or part of the above-described functions. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit, and the integrated unit can be realized in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for easy distinction, and do not limit the protection scope of the present application. The specific working process of the units and modules in the above system can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0127] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in detail in a certain embodiment can refer to the relevant description of other embodiments.

[0128] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0129] In the embodiments provided by the present application, it should be understood that the disclosed apparatus / terminal and method can be implemented in other ways. For example, the apparatus / terminal embodiments described above are merely schematic. The division of the modules or units is merely a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed coupling or direct coupling or communication connection between the units can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or in other forms.

[0130] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. they can be located in one place, or distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0131] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0132] The integrated module / unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. The computer program can implement the steps of the above-mentioned various multi-modal resistance welding power supply control method embodiments when executed by a processor. The computer program includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0133] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A multi-mode resistance welding power supply, characterized in that: It includes a phase-shift full-bridge circuit, a rectifier circuit, a modal control circuit and an inverter circuit connected in sequence; The phase-shifted full-bridge circuit is used to convert the DC power of the DC power supply into AC power and reduce the voltage; The rectifier circuit is used to convert the stepped-down alternating current into stepped-down direct current; The modal control circuit is configured to output the stepped-down DC power at a constant voltage in a constant voltage mode, and to output the stepped-down DC power at a constant current in a constant current mode; The inverter circuit is used to convert the stepped-down direct current into alternating current pulses and output them.

2. The multi-mode resistance welding power supply according to claim 1, characterized in that: The modal control circuit includes an inductor, a capacitor, a first switch branch and a second switch branch; The first end of the inductor constitutes a high-voltage input end of the modal control circuit, and the second end constitutes a high-voltage output end of the modal control circuit; The positive electrode of the capacitor is connected to the first end of the inductor through a first switch branch, and is connected to the second end of the inductor through a second switch branch, and the negative electrode serves as the low-voltage input end and the low-voltage output end of the modal control circuit; The mode control circuit is specifically configured to operate in a constant voltage mode when the first switch branch is disconnected and the second switch branch is turned on.

3. The multi-mode resistance welding power supply according to claim 2, characterized in that: The mode control circuit is specifically configured to operate in a constant current mode when the first switch branch is turned on and the second switch branch is turned off.

4. The multi-mode resistance welding power supply according to claim 3, characterized in that: The first switch branch includes a first diode and a first switch tube, and the second switch branch includes a second switch tube and a third switch tube; The drain of the first switching transistor is connected to the positive electrode of the capacitor, the source is connected to the positive electrode of the first diode, the cathode of the first diode is connected to the first end of the inductor, the drain of the second switching transistor is connected to the positive electrode of the capacitor, the source is connected to the source of the third switching transistor, and the drain of the third switching transistor is connected to the positive electrode of the capacitor; The modal control circuit is specifically configured to operate in a constant current mode when the duty cycle of the inverter circuit is greater than or equal to 0.5, the first switch tube is turned on, and the second switch tube and the third switch tube are turned off.

5. The multi-mode resistance welding power supply according to claim 4, characterized in that: The inverter circuit includes a fourth switching tube, a fifth switching tube, a sixth switching tube and a seventh switching tube; The drain of the fourth switching tube is connected to the drain of the sixth switching tube and constitutes a high-voltage input end of the inverter circuit. The source of the fifth switching tube is connected to the source of the seventh switching tube and constitutes a low-voltage input end of the inverter circuit. The source of the fourth switching tube is connected to the fifth switching tube and constitutes a first output end of the multi-mode resistance welding power supply. The source of the sixth switching tube is connected to the drain of the seventh switching tube and constitutes a second output end of the multi-mode resistance welding power supply. The inverter circuit is specifically configured to convert the stepped-down DC power into positive polarity AC pulses and output them when the fourth switch tube and the seventh switch tube are turned on and the fifth switch tube and the sixth switch tube are turned off. When the fourth switch tube and the seventh switch tube are turned off and the fifth switch tube and the sixth switch tube are turned on, the stepped-down DC power is converted into a negative polarity AC pulse and outputted. When the fourth switch tube and the seventh switch tube, and the fifth switch tube and the sixth switch tube are alternately turned off and on, the stepped-down direct current is converted into a bipolar alternating current pulse and outputted.

6. The multi-mode resistance welding power supply according to claim 5, characterized in that: The modal control circuit is specifically configured to operate in a constant current mode when the duty cycle of the inverter circuit is less than 0.5, the fourth switch tube and the sixth switch tube are disconnected, and the third switch tube is turned on.

7. The multi-mode resistance welding power supply according to any one of claims 1 to 6, characterized in that: The phase-shifted full-bridge circuit includes a transformer, an eighth switching tube, a ninth switching tube, a tenth switching tube, and an eleventh switching tube, and the rectifier circuit includes a second diode, a third diode, a fourth diode, and a fifth diode; The drains of the eighth switching tube and the tenth switching tube are connected and constitute a high-voltage input end of the phase-shifted full-bridge circuit. The sources of the ninth switching tube and the eleventh switching tube are connected and constitute a low-voltage input end of the phase-shifted full-bridge circuit. The source of the eighth switching tube and the drain of the ninth switching tube are connected to the same-name terminal of the primary side of the transformer. The source of the tenth switching tube and the drain of the eleventh switching tube are connected to the opposite-name terminal of the primary side of the transformer. The secondary like-name terminal of the transformer is connected to the positive electrode of the second diode and the negative electrode of the third diode, the secondary unlike-name terminal of the transformer is connected to the positive electrode of the fourth diode and the negative electrode of the fifth diode, the negative electrode of the second diode is connected to the negative electrode of the fourth diode, and constitutes the high-voltage output end of the rectifier circuit, and the negative electrode of the third diode is connected to the negative electrode of the fifth diode, and constitutes the low-voltage output end of the rectifier circuit.

8. A method for controlling a multi-mode resistance welding power supply, characterized in that: The multi-modal resistance welding power supply includes a phase-shift full-bridge circuit, a rectifier circuit, a modal control circuit, and an inverter circuit connected in sequence; the method includes: The phase-shifted full-bridge circuit converts the DC power of the DC power supply into AC power and reduces the voltage; The rectifier circuit converts the stepped-down alternating current into stepped-down direct current; The modal control circuit outputs the stepped-down DC power at a constant voltage in a constant voltage mode, and outputs the stepped-down DC power at a constant current in a constant current mode; The inverter circuit converts the stepped-down DC power into AC pulses and outputs the AC pulses.

9. A terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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