Welding machine control method and system

Abstract

The invention relates to a welding machine control method and system. The welding machine control method comprises the following steps: acquiring current information of each converter module; determining current sharing control parameters based on the current information; and a driving control signal of the welding machine is adjusted according to the current sharing control parameters, and the adjusted driving control signal is output. The driving control signals are adjusted according to the current sharing control parameters, independent regulation and control of the converter modules (for example, independent regulation and control of the output currents of the converter modules) are achieved, balanced current distribution among the converter modules is achieved, the problem of current imbalance in a parallel topology structure of the welding machine is effectively solved, and the service life of the welding machine is prolonged. And meanwhile, rapid and stable current-sharing control on each converter module in the welding machine under a high-frequency switching condition is ensured, so that the conduction loss and the switching loss of the welding machine are reduced, the transient current peak is reduced, the service life of the welding machine is prolonged, and the safety and the reliability of welding equipment are improved.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a welding machine control method and system thereof. Background Art

[0002] With the rapid development of power electronics technology, the power density and efficiency requirements of welding equipment are increasing. Silicon carbide (SiC) materials are widely used in welding equipment due to their wide bandgap, high critical field and high thermal conductivity. As a high-performance welding equipment, silicon carbide welding machine has superior power density and efficiency performance. In practical applications, in order to meet the needs of high-power welding, silicon carbide welding machine usually needs to adopt parallel topology structure for expansion.

[0003] However, although the parallel topology of the silicon carbide welding machine can significantly improve the power level of the welding equipment, there is a problem of current imbalance between the parallel devices caused by factors such as parameter differences between the devices, asymmetric circuit layout, and mismatched parasitic parameters. This current imbalance problem will not only easily lead to the imbalance of the distribution of the conduction loss and switching loss of the silicon carbide welding machine, thereby causing overheating of some devices and shortening the life of the welding equipment; it may also cause excessive transient current spikes, even exceeding the safe working area of ​​the device, thus bringing adverse effects on the reliability and safety of the welding equipment. Summary of the invention

[0004] Based on this, the embodiment of the present application provides a welding machine control method and system thereof, which are conducive to solving the current imbalance problem in the welding machine and realizing current distribution, thereby improving the safety and reliability of the welding machine.

[0005] In order to achieve the above-mentioned purpose, on the one hand, some embodiments of the present application provide a welding machine control method. The welding machine control method includes: obtaining current information of each converter module; determining a current sharing control parameter based on each current information; adjusting a driving control signal of the welding machine according to the current sharing control parameter and outputting the adjusted driving control signal.

[0006] In some embodiments, based on each current information, the current sharing control parameter is determined, including: determining the target current of each converter module; determining the current error according to the current information and the target current of each converter module; based on each current error, determining the current sharing control parameter through variable parameter PI debugging.

[0007] In some embodiments, the variable parameter PI is positively correlated with the absolute value of the current error.

[0008] In some embodiments, determining the target current of each converter module includes: obtaining a total current set value of the welding machine; obtaining the number of modules of the converter module; determining a current set value of each converter module based on a ratio of the total current set value and the number of modules; wherein the target current is the current set value.

[0009] In some embodiments, the driving control signal includes a plurality of duty cycle control signals corresponding to each converter module respectively; the welding machine control method further includes: driving each converter module correspondingly according to each duty cycle control signal.

[0010] In some embodiments, the welding machine control method also includes: obtaining the module number of the converter module and the actual output current value of each converter module; determining the total current output value of the welding machine based on the module number and the actual output current value; obtaining the ratio of the total current output value to the module number as the current output average value; when adjusting the driving control signal of the welding machine according to the current sharing control parameter, compensating the driving control signal according to the difference between the current output average value and the actual output current value.

[0011] On the other hand, the present application also provides a welding machine control system according to some embodiments; the welding machine control system is used to control the welding machine; the welding machine includes multiple converter modules in parallel; the welding machine control system includes an acquisition module and a control module; the acquisition module is configured to: acquire current information of each converter module; the control module is connected to the acquisition module; the control module is configured to: determine a current sharing control parameter based on each current information; and, adjust the driving control signal of the welding machine according to the current sharing control parameter, and output the adjusted driving control signal.

[0012] In some embodiments, the control module includes a processing module and a debugging module; the processing module is connected to the acquisition module; the processing module is configured to: determine the target current of each converter module; and determine the current error based on the current information and the target current of each converter module; the debugging module is connected to the processing module; the debugging module is configured to: based on each current error, determine the current sharing control parameter through variable parameter PI debugging.

[0013] In some embodiments, the drive control signal includes multiple duty cycle control signals corresponding to each converter module respectively; the welding machine control system also includes a drive circuit; the drive circuit is connected to the control module and each converter module; the drive circuit is configured to: drive each converter module according to each duty cycle control signal.

[0014] In some embodiments, the acquisition module is further configured to: acquire the number of modules of the converter module and the actual output current value of each converter module; determine the total current output value of the welding machine according to the number of modules and the actual output current value; and acquire the ratio of the total current output value to the number of modules as the current output average value; the welding machine control system also includes a feedforward circuit; the feedforward circuit is connected to the acquisition module and the control module; the feedforward circuit is configured to: acquire the feedforward difference between the current output average value and the actual output current value, and output the feedforward compensation value after performing proportional integral gain on the feedforward difference; wherein the control module is further configured to: when adjusting the drive control signal of the welding machine according to the current sharing control parameter, compensate the drive control signal according to the feedforward compensation value.

[0015] The embodiments of the present application may or at least have the following advantages:

[0016] In the embodiment of the present application, by respectively acquiring the current information of each converter module in the welding machine, the current sharing control parameter is determined according to the current information, so as to adjust the driving control signal of the welding machine according to the current sharing control parameter and output the adjusted driving control signal. In this way, by adjusting the driving control signal according to the current sharing control parameter, the individual regulation of each converter module is realized (for example, the output current of each converter module is individually regulated) to achieve the current balanced distribution between each converter module, effectively solve the current imbalance problem in the parallel topology structure of the welding machine, and ensure that each converter module in the welding machine is fast, stable and accurate current sharing control under high-frequency switching conditions, thereby reducing the conduction loss and switching loss of the welding machine, reducing transient current spikes, extending the service life of the welding machine, and improving the safety and reliability of the welding equipment.

[0017] The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic flow chart of a welding machine control method provided in some embodiments;

[0020] Figure 2 A schematic flow chart of another welding machine control method provided in some embodiments;

[0021] Figure 3 is a flow chart of step S200 provided in some embodiments;

[0022] Figure 4 A schematic diagram of a flow chart of step S210 provided in some embodiments;

[0023] Figure 5 A schematic flow chart of another welding machine control method provided in some embodiments;

[0024] Figure 6 A schematic flow chart of another welding machine control method provided in some embodiments;

[0025] Figure 7 It is a structural schematic diagram of a welding machine parallel topology structure provided in some embodiments;

[0026] Figure 8 A schematic diagram of the relationship between a variable parameter PI and a current error △x provided in some embodiments;

[0027] Fig. 9 is a structural block diagram of a welding machine control system provided in some embodiments;

[0028] Fig.10 It is a structural block diagram of another welding machine control system provided in some embodiments;

[0029] Fig.11 It is a structural block diagram of another welding machine control system provided in some embodiments;

[0030] Fig.12 It is a structural block diagram of another welding machine control system provided in some embodiments;

[0031] Fig.13 A control block diagram of a welding machine control system provided in some embodiments.

[0032] Description of reference numerals:

[0033] 1-input switch circuit, 2-converter module, 3-welding machine load, 4-power grid, D1-first diode, D2-second diode, D3-third diode, D4-fourth diode, D5-fifth diode, D6-sixth diode, D7-seventh diode, D8-eighth diode, D9-ninth diode, D10-tenth diode, D11-eleventh diode, D12-twelfth diode, D13-thirteenth diode, D14-fourteenth diode, Q1-first transistor, Q2-second transistor, Q3-third transistor, Q4-fourth transistor, C1-first capacitor, L1-first inductor, CT-current transformer, T-transformer, Lr-rectifier inductor, CS-current sensor, A-acquisition module, B-control module, B1-processing module, B2-debugging module, C-drive circuit, D-feedforward circuit. DETAILED DESCRIPTION

[0034] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0036] It should be understood that when an element or layer is referred to as being "on," "adjacent to," or "connected to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types, and / or portions, these elements, components, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, doping type, or portion from another element, component, region, layer, doping type, or portion. Therefore, without departing from the teachings of the present application, the first element, component, region, layer, doping type, or portion discussed below may be represented as a second element, component, region, layer, or portion.

[0037] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that when the terms "consisting of" and / or "comprising" are used in this specification, the presence of the features, integers, steps, operations, elements and / or parts can be determined, but the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups is not excluded. At the same time, when used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0038] Embodiments of the invention are described herein with reference to cross-sectional views that are schematic representations of idealized embodiments (and intermediate structures) of the present application, such that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances are anticipated. Embodiments of the present application should not be limited to the specific shapes of the regions shown herein, but include deviations in shapes due to, for example, manufacturing techniques. Therefore, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shapes of the regions of the device, and do not limit the scope of the present application.

[0039] Some embodiments of the present application provide a welding machine control method, which is beneficial to solving the current imbalance problem in the welding machine and achieving current distribution, thereby improving the safety and reliability of the welding machine.

[0040] In some embodiments, see Figure 1 The welding machine control method includes the following steps S100~S300.

[0041] S100, obtaining current information of each converter module.

[0042] S200, determining a current sharing control parameter based on each current information.

[0043] S300, adjusting the driving control signal of the welding machine according to the current sharing control parameter and outputting the adjusted driving control signal.

[0044] It should be added that, in some embodiments, please refer to Figure 2 Before step S100, the welding machine control method further includes the following step S101.

[0045] S101, constructing a welding machine parallel topology structure; the welding machine parallel topology structure includes a plurality of converter modules connected in parallel.

[0046] In the embodiment of the present application, by respectively acquiring the current information of each converter module in the welding machine, the current sharing control parameter is determined according to the current information, so as to adjust the driving control signal of the welding machine according to the current sharing control parameter and output the adjusted driving control signal. In this way, by adjusting the driving control signal according to the current sharing control parameter, the individual regulation of each converter module is realized (for example, the output current of each converter module is individually regulated) to achieve the current balanced distribution between each converter module, effectively solve the current imbalance problem in the parallel topology structure of the welding machine, and ensure that each converter module in the welding machine is fast, stable and accurate current sharing control under high-frequency switching conditions, thereby reducing the conduction loss and switching loss of the welding machine, reducing transient current spikes, extending the service life of the welding machine, and improving the safety and reliability of the welding machine.

[0047] In some embodiments, see Figure 3 , step S200 includes the following steps S210~S230.

[0048] S210, determining a target current of each converter module.

[0049] S220 , determining a current error according to the current information of each converter module and the target current.

[0050] S230, based on each current error, determine the current sharing control parameter through variable parameter PI debugging.

[0051] In some embodiments, the variable parameter PI is positively correlated with the absolute value of the current error.

[0052] In an embodiment of the present application, the current error of each converter module is obtained respectively, and the current sharing control parameter is determined according to each variable parameter PI which is positively correlated with each current error; wherein the current sharing control parameter is dynamically correlated with the current error of each converter module, so that the current sharing control parameter can respond to the change of the current error in real time to achieve corresponding changes, and can realize real-time dynamic regulation of each converter module when the load in the welding machine changes, so as to quickly realize the current sharing of each converter module; in this way, the dynamic response performance of the welding machine control is improved, ensuring that each converter module in the welding machine can achieve fast, accurate and stable current sharing control under high-frequency switching conditions.

[0053] In some embodiments, see Figure 4 , step S210 includes the following steps S211~S213.

[0054] S211, obtaining a total current given value of the welding machine.

[0055] S212, obtaining the module quantity of the converter module.

[0056] S213, determining a current given value for each converter module according to a ratio of a total current given value to the number of modules; wherein the target current is the current given value.

[0057] In the embodiment of the present application, the ratio of the total current set value and the number of modules is calculated to obtain the average current value that needs to be allocated to each converter module as the current set value (i.e., the target current); in this way, the calculated current set value can be adjusted accordingly according to the number of converter modules in parallel in the parallel topology structure of the welding machine, so that the welding machine control method can be applicable to welding machine control under different numbers of converter modules, thereby improving the applicability of the welding machine control method and also improving the accuracy of the current distribution to each converter module in the welding machine.

[0058] In some embodiments, the driving control signal includes a plurality of duty cycle control signals corresponding to each converter module; see Figure 5 The welding machine control method further includes the following step S400.

[0059] S400: driving each converter module according to each duty cycle control signal.

[0060] In some embodiments, see Figure 6 The welding machine control method also includes the following steps S510~S540.

[0061] S510, obtaining the number of converter modules and the actual output current value of each converter module.

[0062] S520, determining the total current output value of the welding machine according to the number of modules and the actual output current value.

[0063] S530, obtaining a ratio of a total current output value to the number of modules as a current output average value.

[0064] Here, steps S510 to S530 are performed before step S300. The acquisition of the number of modules in step S510 can be achieved through step S212, and the acquisition of the actual output current value in step S510 can be achieved through step S100; steps S520 and S530 can be performed after step S100 or step S200.

[0065] S540, when adjusting the driving control signal of the welding machine according to the current sharing control parameter, the driving control signal is compensated according to the difference between the current output average value and the actual output current value.

[0066] Here, step S540 may be performed synchronously with step S300.

[0067] In an embodiment of the present application, the total current output value actually output by the welding machine is obtained to calculate the current output average value of any converter module, and the actual output current value of each converter module is monitored in real time, and the difference between the current output average value and the actual output current value of each converter module is obtained in real time to compensate the drive control signal in real time according to the difference; in this way, by setting a monitoring link in the welding machine control method, the control error can be automatically repaired, thereby improving the dynamic response performance of the welding machine control, as well as the accuracy and stability of the current sharing control of each converter module.

[0068] It should be understood that although Figure 1 to Figure 6 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 to Figure 6 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0069] In order to more clearly illustrate the welding machine control method in some of the above embodiments; Figure 7~Figure 8 Understand.

[0070] In some embodiments, before step S100 , the welding machine control method further includes step S101 .

[0071] In step S101, a welding machine parallel topology structure is constructed; the welding machine parallel topology structure includes a plurality of converter modules 2 connected in parallel.

[0072] For some examples, see Figure 7 The parallel topology structure of the welding machine includes an input switch circuit 1, a plurality of parallel converter modules 2 and a welding machine load 3. The input switch circuit 1 is connected to a power grid 4; the plurality of parallel converter modules 2 are connected to the input switch circuit 1; and the welding machine load 3 is connected to the plurality of parallel converter modules 2.

[0073] For example, please continue to see Figure 7, the input switch circuit 1 includes: a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5 and a sixth diode D6. Among them, the cathode of the second diode D2 is connected to the anode of the first diode D1; the cathode of the fourth diode D4 is connected to the anode of the third diode D3; the cathode of the sixth diode D6 is connected to the anode of the fifth diode D5; the cathode of the first diode D1, the cathode of the third diode D3 and the cathode of the fifth diode D5 are all connected; the anode of the second diode D2, the anode of the fourth diode D4 and the anode of the sixth diode D6 are all connected.

[0074] For example, please continue to see Figure 7 The input switch circuit 1 further includes a first capacitor C1; wherein the cathode of the fifth diode D5 is connected to the anode of the sixth diode D6 via the first capacitor C1.

[0075] By way of example, the power grid 4 may be a three-phase power grid, for example.

[0076] For example, please continue to see Figure 7 , the power grid 4 includes: a first phase output Ua, a second phase output Ub and a third phase output Uc. The first phase output Ua is connected to the anode of the first diode D1 and the cathode of the second diode D2; the second phase output Ub is connected to the anode of the third diode D3 and the cathode of the fourth diode D4; the third phase output Uc is connected to the anode of the fifth diode D5 and the cathode of the sixth diode D6.

[0077] For example, please continue to see Figure 7Any converter module 2 includes: a seventh diode D7, an eighth diode D8, a ninth diode D9, a tenth diode D10, an eleventh diode D11, a twelfth diode D12, a thirteenth diode D13, a fourteenth diode D14, a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a first inductor L1, a current transformer CT and a transformer T. The first end of the first transistor Q1 is connected to the first end of the third transistor Q3 and the cathode of the fifth diode D5; the second end of the first transistor Q1 is connected to the first end of the second transistor Q2; the second end of the second transistor Q2 is connected to the second end of the fourth transistor Q4 and the anode of the sixth diode D6; the second end of the third transistor Q3 is connected to the first end of the fourth transistor Q4. The first end of the first coil of the transformer T is connected to the second end of the first transistor Q1 via the first inductor L1 and the current transformer CT; the second end of the first coil of the transformer T is connected to the first end of the fourth transistor Q4; the first end of the second coil of the transformer T is connected to the anode of the eleventh diode D11; the second end of the second coil of the transformer T is connected to the cathode of the fourteenth diode D14. The anode of the eleventh diode D11 is connected to the cathode of the twelfth diode D12; the cathode of the eleventh diode D11 is connected to the cathode of the thirteenth diode D13; the anode of the fourteenth diode D14 is connected to the anode of the twelfth diode D12; the anode of the thirteenth diode D13 is connected to the cathode of the fourteenth diode D14.

[0078] For example, the first transistor Q1, the second transistor Q2, the third transistor Q3, and the fourth transistor Q4 all include but are not limited to silicon carbide (SiC) insulated gate bipolar transistors (IGBT) or silicon carbide (SiC) metal oxide semiconductor field effect transistors (MOSFET).

[0079] For some examples, see Figure 7 The converter module 2 also includes a rectifier inductor Lr; the welding machine load 3 includes a positive electrode V o + and negative electrode V o - The cathode of the thirteenth diode D13 is connected to the positive electrode V of the welding machine load 3 via the rectifier inductor Lr. o + The anode of the fourteenth diode D14 is connected to the negative electrode V of the welding machine load 3 o - connected.

[0080] In some embodiments, the welding machine control method includes steps S100 to S300.

[0081] In step S100 , current information of each converter module 2 is acquired.

[0082] For some examples, see Figure 7 The parallel topology structure of the welding machine also includes a plurality of current sensors CS; each current sensor CS is located at the positive electrode V of the welding machine load 3 o + Between each rectifier inductor Lr. Each current sensor CS is set corresponding to each converter module 2 and is used to obtain the current information of each converter module 2 in real time.

[0083] It should be noted that the current information may include the actual output current value I of each converter module 2. k .

[0084] In step S200, a current sharing control parameter D is determined based on each current information.

[0085] In some examples, step S200 includes steps S210 to S230.

[0086] In step S210, the target current I of each converter module 2 is determined. ref / n.

[0087] For example, the target current I ref / n is equal to the total current setting value I of the welding machine ref The ratio between the number n of converter modules 2.

[0088] In some embodiments, step S210 includes the following steps S211 to S213.

[0089] In step S211, the total current given value I of the welding machine is obtained. ref .

[0090] It should be noted that the total current given value I ref It may be a preset value or a standard value determined according to the performance of the welding machine, and the present disclosure is not limited thereto.

[0091] In step S212 , the module number n of the converter module 2 is obtained.

[0092] In step S213, according to the total current given value I ref The ratio of the target current I ref / n is the given current value.

[0093] In step S220, according to the current information of each converter module 2 and the target current I ref / n determines the current error △x.

[0094] For example, the current error Δx is the actual output current value I of each converter module 2 k With the target current I ref / nThe difference between.

[0095] In step S230, refer to Figure 8 and Fig.13 Based on each current error △x, the current sharing control parameter D is determined through variable parameter PI debugging.

[0096] In some examples, the variable parameter PI includes a proportional gain k p and integral gain k i .

[0097] According to the above example, step S230 includes the following steps: p and current error △x, determine the proportional control term; according to the integral gain k i The integral control term is determined based on the current error △x. The current sharing control parameter D is determined based on the proportional control term and the integral control term.

[0098] For example, the proportional gain k p Multiply it by the current error △x to get the proportional control term; i Multiply it with the current error △x, and add the product to the integral accumulated value to obtain the integral control term.

[0099] In some embodiments, the variable parameter PI is positively correlated with the absolute value of the current error Δx.

[0100] For some examples, see Figure 8 , proportional gain k p It is positively correlated with the absolute value of the current error △x; the integral gain k i It is positively correlated with the absolute value of the current error △x.

[0101] For example, the proportional gain k p The absolute value of the integral gain k i The absolute value of .

[0102] In step S300, the driving control signal of the welding machine is adjusted according to the current sharing control parameter D and the adjusted driving control signal is output.

[0103] For example, the driving control signal may be a pulse width modulation (PWM) signal.

[0104] In some examples, the driving control signal includes a plurality of duty cycle control signals corresponding to each converter module 2 .

[0105] It should be noted that, since the current equalization control parameter D is determined based on the current error △x of each converter module 2, by adjusting the driving control signal of the welding machine according to the current equalization control parameter D, it is possible to achieve separate regulation of multiple duty cycle control signals of each converter module 2, thereby achieving balanced current distribution among the converter modules 2.

[0106] In some embodiments, the welding machine control method further includes step S400.

[0107] In step S400 , each converter module 2 is driven correspondingly according to each duty cycle control signal.

[0108] In some embodiments, the welding machine control method further includes steps S510 to S540.

[0109] In step S510, the number n of converter modules 2 and the actual output current value I of each converter module 2 are obtained. k .

[0110] For example, the actual output current value I of each converter module 2 is k It can be collected in real time through measuring devices such as current sensors.

[0111] In step S520, according to the number of modules n and the actual output current value I k , get the total current output value I of the welding machine out .

[0112] It should be noted that the total current output value I of the welding machine in step S520 is out = equal to the actual output current value I of each converter module 2 obtained in step S510 k The sum of all additions.

[0113] For example, the total current output value of the welding machine I out It can be collected in real time through measuring devices such as current sensors.

[0114] In step S530, the total current output value I is obtained. out Ratio to the number of modules n, as the average current output I out / n.

[0115] It should be noted that the current output average value I in step S530 is out / n is the total current output value I obtained in step S520 out The ratio between the number of modules n obtained in step S510.

[0116] It should be noted that the average current output I out / n means: the current output of the welding machine is the total current output value I out In the case of , in order to achieve current sharing of each converter module 2, the average current value required to be allocated to each converter module 2.

[0117] In step S540, when adjusting the driving control signal of the welding machine according to the current sharing control parameter D, the current output average value I out / n and actual output current value I k The difference between the driving control signal and the

[0118] In some examples, step S540 includes the following steps: outputting the average current value I out / n and the actual output current value I k The difference between the values ​​of ΔD and ΔD is used to determine the compensation parameter △D; and the drive control signal is compensated according to the compensation parameter △D.

[0119] The present application also provides a welding machine control system according to some embodiments; the welding machine control system is used to control the welding machine; the welding machine control system can be used to execute the welding machine control method in some of the above embodiments. The welding machine control system also has the technical advantages of the above welding machine control method. It should be noted that the parts that are the same or corresponding to the above embodiments can refer to the corresponding description of the above embodiments, and will not be described in detail below.

[0120] In some embodiments, see Fig. 9 The welding machine includes a plurality of converter modules 2 connected in parallel; the welding machine control system includes an acquisition module A and a control module B; the acquisition module A is configured to: acquire current information of each converter module 2; the control module B is connected to the acquisition module A; the control module B is configured to: determine a current sharing control parameter D based on each current information; and adjust a driving control signal PWM of the welding machine according to the current sharing control parameter D, and output the adjusted driving control signal PWM.

[0121] For example, the current information may include the actual output current value I of each converter module 2. k .

[0122] In some embodiments, see Fig.10 The control module B includes a processing module B1 and a debugging module B2; the processing module B1 is connected to the acquisition module A; the processing module B1 is configured to: determine the target current I of each converter module 2 ref / n; and, according to the current information of each converter module 2 and the target current I ref / n determines the current error △x; the debugging module B2 is connected to the processing module B1; the debugging module B2 is configured to: based on each current error △x, determine the current sharing control parameter D through variable parameter PI debugging.

[0123] In some examples, the variable parameter PI is positively correlated with the current error.

[0124] Illustratively, the tuning module B2 includes a proportional-integral controller.

[0125] In some embodiments, see Fig.11 The drive control signal PWM includes a plurality of duty cycle control signals corresponding to each converter module 2; the welding machine control system also includes a drive circuit C; the drive circuit C is connected to the control module B and each converter module 2; the drive circuit C is configured to: drive each converter module 2 according to each duty cycle control signal.

[0126] In some embodiments, the acquisition module A is further configured to: acquire the total current output value I of the welding machine out ; Obtain the number of modules of the converter module 2 and the actual output current value of each converter module 2; and, obtain the total current output value I out Ratio to the number of modules n, as the average current output I out / n; see Fig.12 The welding machine control system also includes a feedforward circuit R; the feedforward circuit R is connected to the acquisition module A and the control module B; the feedforward circuit R is configured to: obtain the current output average value I out / n and the actual output current value I k The control module B is further configured to compensate the driving control signal PWM of the welding machine according to the feedforward compensation value △D when adjusting the driving control signal PWM of the welding machine according to the current sharing control parameter D.

[0127] Illustratively, the feedforward circuit R includes a proportional-integral controller.

[0128] From above, please refer to Fig.13 In some embodiments, a welding machine control system including an acquisition module A, a control module B and a feedforward circuit R is taken as an example to illustrate the control of the welding machine control system.

[0129] It should be noted that after the acquisition module A acquires the current information of each converter module 2, Fig.13 As shown in:

[0130] (1) The processing module B1 generates a target current I of each converter module 2 according to the target current I ref / n and the actual output current value I of each converter module 2 kThe current error Δx of each converter module 2 is determined.

[0131] (2) Through the debugging module B2, the proportional integral gain (PI chg ) and then output the current sharing control parameter D.

[0132] (3) Obtain the current output average value I through the feedforward circuit R out / n and the actual output current value I k The feedforward difference is taken and the proportional integral gain (i.e. PI0) is applied to the feedforward difference to output the feedforward compensation value △D.

[0133] (4) adjusting the driving control signal PWM of the welding machine according to the current sharing control parameter D through the control module B (such as the debugging module B2); and compensating the driving control signal PWM according to the feedforward compensation value △D.

[0134] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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.

[0135] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A welding machine control method, characterized in that: The welding machine includes a plurality of converter modules connected in parallel; the welding machine control method includes: Acquiring current information of each of the converter modules; Based on each of the current information, determining a current sharing control parameter; The driving control signal of the welding machine is adjusted according to the current sharing control parameter and the adjusted driving control signal is output.

2. The welding machine control method according to claim 1, characterized in that: The determining of the current sharing control parameter based on each of the current information includes: Determining a target current of each of the converter modules; determining a current error according to the current information of each converter module and the target current; Based on each of the current errors, the current sharing control parameter is determined through variable parameter PI debugging.

3. The welding machine control method according to claim 2, characterized in that: The variable parameter PI is positively correlated with the absolute value of the current error.

4. The welding machine control method according to claim 2, characterized in that: The determining of the target current of each converter module comprises: Obtaining a total current given value of the welding machine; Obtaining the module quantity of the converter module; The current given value of each converter module is determined according to the ratio of the total current given value to the number of modules; wherein the target current is the current given value.

5. The welding machine control method according to claim 1, characterized in that: The driving control signal includes a plurality of duty cycle control signals corresponding to each of the converter modules; The welding machine control method further comprises: Each of the converter modules is driven accordingly according to each of the duty cycle control signals.

6. The welding machine control method according to any one of claims 1 to 5, characterized in that: Also includes: Obtaining the number of converter modules and the actual output current value of each converter module; Determining a total current output value of the welding machine according to the number of modules and the actual output current value; Obtaining a ratio of the total current output value to the number of modules as a current output average value; When the driving control signal of the welding machine is adjusted according to the current sharing control parameter, the driving control signal is compensated according to the difference between the current output average value and the actual output current value.

7. A welding machine control system, characterized in that: Used to control a welding machine; the welding machine includes a plurality of converter modules connected in parallel; the welding machine control system includes: An acquisition module is configured to: acquire current information of each of the converter modules; The control module is connected to the acquisition module and is configured to: determine the current sharing control parameter based on each current information; and adjust the driving control signal of the welding machine according to the current sharing control parameter, and output the adjusted driving control signal.

8. The welding machine control system according to claim 7, characterized in that: The control module comprises: A processing module, connected to the acquisition module, configured to: determine a target current of each of the converter modules; and determine a current error according to the current information of each of the converter modules and the target current; The debugging module is connected to the processing module and is configured to: determine the current sharing control parameter through variable parameter PI debugging based on each of the current errors.

9. The welding machine control system according to claim 7, characterized in that: The driving control signal includes a plurality of duty cycle control signals corresponding to each of the converter modules; The welding machine control system also includes: The driving circuit is connected to the control module and each of the converter modules, and is configured to drive each of the converter modules correspondingly according to each of the duty cycle control signals.

10. The welding machine control system according to any one of claims 7 to 9, characterized in that: The acquisition module is further configured to: acquire the number of modules of the converter modules and the actual output current value of each converter module; determine the total current output value of the welding machine according to the number of modules and the actual output current value; And, obtaining a ratio of the total current output value to the number of modules as an average current output value; The welding machine control system also includes: A feedforward circuit is connected to the acquisition module and the control module, and is configured to: acquire a feedforward difference between the current output average value and the actual output current value, and output a feedforward compensation value after performing proportional integral gain on the feedforward difference; Wherein, the control module is further configured to: when adjusting the driving control signal of the welding machine according to the current sharing control parameter, compensate the driving control signal according to the feedforward compensation value.

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