A PWM control method, system, device and medium suitable for sudden current tracking

Abstract

The present invention provides a PWM control method, system, device and medium suitable for sudden current tracking. The method calculates a current setpoint of a PWM rectifier based on the input current of a nonlinear load, then designs a hysteresis controller and an SVPWM controller based on the system parameters of the PWM rectifier and the grid's requirements for the harmonic content of the grid-connected current, respectively. Then, the current tracking error is calculated based on the current setpoint of the PWM rectifier and the actual current value of the PWM rectifier. Finally, switching is performed between the hysteresis controller and the SVPWM controller based on the magnitude of the current tracking error. Since the equivalent switching frequency and equivalent current ripple of the independently designed hysteresis controller and SVPWM controller are the same, the switching process does not affect the switching frequency and system efficiency of the system. At the same time, the introduction of the switching control method enables the PWM controller to have high current steady-state accuracy and fast current tracking performance, and the spectrum distribution is regular, which does not affect the filtering performance of the passive filter in the PWM rectifier.

Description

Technical Field

[0001] The present invention belongs to the technical field of power systems and relates to a PWM control method, system, device and medium suitable for sudden current tracking. Background Art

[0002] Three-phase voltage source rectifiers have been widely used in industry due to their advantages, such as controllable power factor, simple circuit structure, low input current THD, and minimal output voltage ripple. Common direct current control methods for three-phase voltage source rectifiers include hysteresis current control and space vector control (SVPWM). Hysteresis current control uses a nonlinear link—a hysteresis loop—as the current control structure. When the current deviation exceeds the hysteresis loop width, the main circuit power switch switches, forcing the current deviation to decrease. Space vector control (SVPWM) utilizes the space voltage vector command output by a current regulator in a synchronously rotating coordinate system, then causes the space vector to track the voltage vector command to achieve current control. Hysteresis modulation control is simple, offers good real-time performance, fast response, and excellent dynamic regulation performance. However, it suffers from high and variable switching frequency, high switching losses, and poor steady-state performance. SVPWM, on the other hand, has a fixed switching frequency, high voltage utilization, and excellent steady-state performance. For sudden load fluctuations, it is necessary to develop a hysteresis SVPWM control method for rectifiers, combining the advantages of both hysteresis and SVPWM current control methods.

[0003] Hysteresis modulation offers a fast response but a variable switching frequency and a dispersed spectrum. SVPWM offers high steady-state accuracy, a fixed switching frequency, and a concentrated spectrum, but a slower response. Hysteresis SVPWM has the potential to combine the advantages of both modulation methods, but the principles of the two methods differ significantly, and control performance is difficult to predict. Consequently, practical control system design lacks quantitative theoretical guidance. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a PWM control method, system, device and medium suitable for sudden current tracking, which solves the problems existing in the prior art that hysteresis modulation has a fast response speed but an unstable switching frequency and a dispersed spectrum distribution, and SVPWM has high steady-state accuracy, a fixed switching frequency, a concentrated spectrum distribution but a slow response speed.

[0005] The present invention is achieved through the following technical solutions:

[0006] A PWM control method suitable for sudden current tracking, characterized by comprising the following steps:

[0007] S1: Based on the input AC line voltage and input power of the rectifier, the input AC phase voltage, input current, output DC voltage, output DC power, and output DC current are obtained, and the connection inductance, connection resistance, output DC resistance, and output DC capacitance are calculated.

[0008] S2: Collect the AC voltage of the grid, the DC voltage of the rectifier, the AC current of the grid, the AC current of the nonlinear load, and the AC current of the rectifier through voltage Hall elements and current Hall elements;

[0009] S3: Based on the iTHD of the rectifier input current, the hysteresis current width of the hysteresis control and the switching frequency of the SVPWM control are obtained;

[0010] S4: Obtain a given value of the AC current of the PWM rectifier according to the AC current of the nonlinear load;

[0011] S5: Selecting a hysteresis controller of the PWM rectifier according to the hysteresis current width of the hysteresis control to obtain a switching pulse of the hysteresis controller;

[0012] S6: Selecting an SVPWM controller of the PWM rectifier according to the switching frequency of the SVPWM control to obtain a switching pulse of the SVPWM controller;

[0013] S7: obtaining a maximum current error value according to a given value of the PWM rectifier AC current and an actual value of the PWM rectifier AC current;

[0014] S8: Obtain the switching pulse of the hysteresis SVPWM controller according to the maximum current error and the switching width.

[0015] Furthermore, the input AC phase voltage is:

[0016]

[0017] Among them, U ab is the input AC line voltage;

[0018] The input current is:

[0019]

[0020] Among them, P in is the power of the PWM rectifier;

[0021] The connection inductance is:

[0022]

[0023] Among them, k l is the reactor coefficient, ω is the grid angular frequency; the connection resistance is:

[0024]

[0025] Where η is the system efficiency.

[0026] Furthermore, the output DC voltage is:

[0027] U dc =1.7U ab ;

[0028] Among them, 1.7 is the boost coefficient;

[0029] The output DC power is:

[0030] P out =P in ;

[0031] The output DC current is:

[0032]

[0033] The output DC resistance is:

[0034]

[0035] The output DC capacitance is:

[0036]

[0037] Among them, k c is the capacitor ripple factor.

[0038] Furthermore, the hysteresis current width is:

[0039]

[0040] Among them, iTHD is the grid-side current harmonic distortion rate;

[0041] The switching frequency of the SVPWM controller is:

[0042]

[0043] Where L is the connection inductance.

[0044] Furthermore, the harmonic current of the nonlinear load is:

[0045]

[0046] in, is the fundamental component of the load current; the current setting value of the PWM rectifier is:

[0047] Furthermore, the absolute value of the current set value of the PWM rectifier is:

[0048]

[0049] The current error of the PWM rectifier is:

[0050]

[0051] Furthermore, the switching width of the PWM rectifier is:

[0052] h=kH;

[0053] Wherein, k is the switching coefficient, which is greater than 1 in principle and generally ranges from 3 to 10.

[0054] A typical value is 6;

[0055] The Schmitt switching width of the PWM rectifier is:

[0056] dh=d*h;

[0057] Get the input status of the RS trigger. The method to get the input status of the RS trigger is:

[0058]

[0059] Wherein, k is the switching width coefficient and is the Schmidt switching width coefficient.

[0060] A rectifier hysteresis SVPWM control system suitable for sudden current tracking, comprising:

[0061] The DC parameter acquisition module is used to obtain the input AC phase voltage, input current, output DC voltage, output DC power, and output DC current according to the input AC line voltage and input power of the rectifier, and calculate the connection inductance, connection resistance, output DC resistance, and output DC capacitance;

[0062] AC parameter acquisition module, used to collect the AC voltage of the power grid, the DC voltage of the rectifier, the AC current of the power grid, the AC current of the nonlinear load, and the AC current of the rectifier through voltage Hall elements and current Hall elements;

[0063] A hysteresis current width and switching frequency acquisition module is used to obtain the hysteresis current width of the hysteresis control and the switching frequency of the SVPWM control according to the iTHD of the rectifier input current;

[0064] The AC current given value acquisition module is used to obtain the given value of the AC current of the PWM rectifier according to the AC current of the nonlinear load;

[0065] A switching pulse acquisition module of the hysteresis controller is used to select the hysteresis controller of the PWM rectifier according to the hysteresis current width of the hysteresis control to obtain the switching pulse of the hysteresis controller;

[0066] The switching pulse acquisition module of the SVPWM controller is used to select the SVPWM controller of the PWM rectifier according to the switching frequency of the SVPWM control and obtain the switching pulse of the SVPWM controller;

[0067] A current error maximum value acquisition module is used to obtain the current error maximum value according to the given value of the PWM rectifier AC current and the actual value of the PWM rectifier AC current;

[0068] The switching pulse acquisition module of the SVPWM controller is used to obtain the switching pulse of the hysteresis SVPWM controller according to the maximum current error and the switching width.

[0069] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, steps of a PWM control method suitable for sudden current tracking are implemented.

[0070] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a PWM control method suitable for sudden current tracking.

[0071] Compared with the prior art, the present invention has the following beneficial technical effects:

[0072] The present invention provides a PWM control method, system, device and medium suitable for sudden current tracking. The method calculates a current setpoint of a PWM rectifier based on the input current of a nonlinear load, then designs a hysteresis controller and an SVPWM controller based on the system parameters of the PWM rectifier and the grid's requirements for the harmonic content of the grid-connected current, respectively. Then, the current tracking error is calculated based on the current setpoint of the PWM rectifier and the actual current value of the PWM rectifier. Finally, switching is performed between the hysteresis controller and the SVPWM controller based on the magnitude of the current tracking error. Since the equivalent switching frequency and equivalent current ripple of the independently designed hysteresis controller and SVPWM controller are the same, the switching process does not affect the switching frequency and system efficiency of the system. At the same time, the introduction of the switching control method enables the PWM controller to have high current steady-state accuracy and fast current tracking performance, and the spectrum distribution is regular, which does not affect the filtering performance of the passive filter in the PWM rectifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 This is a flow chart of a PWM control method suitable for sudden current tracking according to the present invention;

[0074] Figure 2 This is a principle block diagram of the main circuit of the PWM rectifier of the present invention;

[0075] Figure 3 1 is a principle block diagram of the rectifier hysteresis controller of the present invention;

[0076] Figure 4 1 is a functional block diagram of the SVPWM controller of the rectifier of the present invention;

[0077] Figure 5 This is a principle block diagram of the switching control of the hysteresis SVPWM controller of the PWM rectifier of the present invention.

[0078] Figure 6 1 is a functional block diagram of a hysteresis-band SVPWM controller for a PWM rectifier according to the present invention;

[0079] Figure 7 (a) is the experimental voltage and current waveform of the rectifier hysteresis control method. Figure 7 (b) is the experimental voltage and current waveform of the rectifier SVPWM control method, Figure 7 (c) Experimental voltage and current waveforms of the rectifier hysteresis SVPWM control method;

[0080] Figure 8 (a) is the current spectrum waveform of the rectifier hysteresis control method, Figure 8 (b) is the current spectrum waveform of the rectifier SVPWM control method, Figure 8 (c) is the current spectrum waveform of the rectifier hysteresis SVPWM control method. DETAILED DESCRIPTION

[0081] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0082] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0083] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0084] The present invention provides a PWM control method, system, device and medium suitable for sudden current tracking, which solves the problems existing in the prior art that hysteresis modulation has a fast response speed but an unstable switching frequency and a dispersed spectrum distribution, and SVPWM has high steady-state accuracy, a fixed switching frequency, a concentrated spectrum distribution but a slow response speed.

[0085] The technical solution adopted by the present invention comprises the following steps:

[0086] S1: Based on the input AC line voltage and input power of the rectifier, the input AC phase voltage, input current, output DC voltage, output DC power, and output DC current are obtained, and the connection inductance, connection resistance, output DC resistance, and output DC capacitance are calculated.

[0087] S2: The AC voltage of the power grid, the DC voltage of the rectifier, the AC current of the power grid, the AC current of the nonlinear load, and the AC current of the rectifier are collected through the voltage Hall element and the current Hall element, such as Figure 2 As shown;

[0088] S3: Based on the iTHD of the rectifier input current, the hysteresis current width of the hysteresis control and the switching frequency of the SVPWM control are obtained;

[0089] S4: Obtain a given value of the AC current of the PWM rectifier according to the AC current of the nonlinear load;

[0090] S5: According to the hysteresis current width of the hysteresis control, select the hysteresis controller of the PWM rectifier to obtain the switching pulse of the hysteresis controller, such as Figure 3 As shown;

[0091] S6: According to the switching frequency of SVPWM control, select the SVPWM controller of the PWM rectifier and obtain the switching pulse of the SVPWM controller, such as Figure 4 As shown;

[0092] S7: obtaining a maximum current error value according to a given value of the PWM rectifier AC current and an actual value of the PWM rectifier AC current;

[0093] S8: According to the maximum current error and the switching width, the switching pulse of the hysteresis SVPWM controller is obtained, such as Figure 5 shown.

[0094] Specifically, the input AC phase voltage is:

[0095]

[0096] Among them, U ab is the input AC line voltage;

[0097] The input current is:

[0098]

[0099] Among them, P in is the power of the PWM rectifier;

[0100] The connection inductance is:

[0101]

[0102] Among them, k l is the reactor coefficient, ω is the grid angular frequency;

[0103] The connection resistance is:

[0104]

[0105] Where η is the system efficiency.

[0106] Specifically, the output DC voltage is:

[0107] U dc =1.7U ab ;

[0108] Among them, 1.7 is the boost coefficient;

[0109] The output DC power is:

[0110] P out =ηP in ;

[0111] The output DC current is:

[0112]

[0113] The output DC resistance is:

[0114]

[0115] The output DC capacitance is:

[0116]

[0117] Among them, k c is the capacitor ripple factor.

[0118] Specifically, the hysteresis current width is:

[0119]

[0120] Among them, iTHD is the grid-side current harmonic distortion rate.

[0121] The switching frequency of the SVPWM controller is:

[0122]

[0123] Where L is the connection inductance.

[0124] Specifically, the harmonic current of the nonlinear load is:

[0125]

[0126] in, is the fundamental component of the load current.

[0127] The current setting value of the PWM rectifier is:

[0128]

[0129] Specifically, the absolute value of the current set value of the PWM rectifier is:

[0130]

[0131] The current error of the PWM rectifier is:

[0132]

[0133] Specifically, the switching width of the PWM rectifier is:

[0134] h=kH;

[0135] Here, k is the switching coefficient. In principle, k is greater than 1, and generally ranges from 3 to 10, with a typical value of 6.

[0136] The Schmitt switching width of the PWM rectifier is:

[0137] dh=d*h;

[0138] Get the input status of the RS trigger. The method to get the input status of the RS trigger is:

[0139]

[0140] Wherein, k is the switching width coefficient and is the Schmidt switching width coefficient.

[0141] A preferred embodiment provided by the present invention is:

[0142] In step S1, the input AC phase voltage, input current, output DC voltage, output DC power, and output DC current are calculated, and the connection inductance, connection resistance, output DC resistance, and output DC capacitance are calculated. Specifically, the following steps are performed:

[0143] According to the connected grid voltage, the input AC line voltage is determined as:

[0144] U ab =380V (1)

[0145] According to the power of the load, the power of the PWM rectifier is determined as:

[0146] P in =5kW (2)

[0147] Calculate the input AC phase voltage as:

[0148]

[0149] Calculate the input current as:

[0150]

[0151] Calculate the connection inductance as:

[0152]

[0153] Calculate the connection resistance as:

[0154]

[0155] Calculate the output DC voltage as:

[0156] U dc =1.7U ab =1.7*380=650V (7)

[0157] Calculate the output DC power as:

[0158] P out =ηP in =0.975*5000=4.875kW (8)

[0159] Calculate the output DC current as:

[0160]

[0161] Calculate the output DC resistance as:

[0162]

[0163] Calculate the output DC capacitance as:

[0164]

[0165] Where: k l is the reactor coefficient, η is the system efficiency, k c is the capacitor coefficient;

[0166] Step S3 is implemented according to the following steps:

[0167] The hysteresis current width of the hysteresis controller is calculated as:

[0168]

[0169] The switching frequency of the SVPWM controller is calculated as:

[0170]

[0171] Step S4 is specifically implemented according to the following steps:

[0172] Calculate the harmonic current of nonlinear load as:

[0173]

[0174] The current setting value of the PWM rectifier is calculated as:

[0175]

[0176] Step S7 is specifically implemented according to the following steps:

[0177] Calculate the absolute value of the current reference value of the PWM rectifier:

[0178]

[0179] The current setting value of the PWM rectifier is calculated as:

[0180]

[0181] Step S8 is specifically implemented according to the following steps:

[0182] Calculate the switching width of the PWM rectifier:

[0183] h=kH=6A (18)

[0184] Calculate the Schmitt switching width of the PWM rectifier:

[0185] dh=d*h=2A (19)

[0186] Get the input status of the RS flip-flop.

[0187] The method to obtain the input state of the RS flip-flop is:

[0188]

[0189] Among them, k is the switching width coefficient, which is generally taken as 5, and d is the Schmidt switching width coefficient, which is generally taken as 1 / 3.

[0190] In order to verify the rectifier hysteresis and hybrid SVPWM control method suitable for sudden current tracking, experiments were carried out on the experimental platform, such as Figure 6 As shown in FIG, it is a principle block diagram of the PWM rectifier hysteresis loop and the SVPWM controller switching control.

[0191] like Figure 7 The experimental comparison waveforms shown in FIG. 1 prove that the hysteresis SVPWM control method for the rectifier suitable for sudden current tracking of the present invention has high current steady-state accuracy and fast current tracking performance, wherein Figure 7 (a) The experimental voltage and current waveforms of the rectifier hysteresis control method are shown. It has the fastest dynamic response and can perform fast current tracking at the six current change points in each grid cycle of the nonlinear load. Figure 7 (b) The experimental voltage and current waveforms of the rectifier SVPWM control method are shown. It has the highest steady-state accuracy, but cannot respond quickly to current changes at the six current sudden change points. Figure 7 (c) is the experimental voltage and current waveform of the rectifier hysteresis SVPWM hybrid control method. At the six current sudden change points, it switches to hysteresis control to quickly respond to current changes. In other steady-state current intervals, it switches to SVPWM to achieve a stable output current. Figure 7 From the current waveform, it can be seen that the dynamic performance of the hysteresis SVPWM method is close to that of the hysteresis control method, and the steady-state performance is close to that of the SVPWM control method.

[0192] like Figure 8 The experimental waveforms shown prove that the hysteresis SVPWM hybrid control method for rectifiers suitable for sudden current tracking of the present invention has the characteristics of regular distribution of harmonic spectrum, which is mainly distributed near multiples of the switching frequency, making it easy to design passive filters when filtering out higher frequency harmonics. Figure 8 (a) is the current spectrum waveform of the rectifier hysteresis control method, Figure 8(b) is the current spectrum waveform of the rectifier SVPWM control method, Figure 8 (c) is the current spectrum waveform of the rectifier hysteresis and SVPWM hybrid control method.

[0193] The present invention provides a rectifier hysteresis SVPWM control system suitable for sudden current tracking, comprising:

[0194] The DC parameter acquisition module is used to obtain the input AC phase voltage, input current, output DC voltage, output DC power, and output DC current according to the input AC line voltage and input power of the rectifier, and calculate the connection inductance, connection resistance, output DC resistance, and output DC capacitance;

[0195] AC parameter acquisition module, used to collect the AC voltage of the power grid, the DC voltage of the rectifier, the AC current of the power grid, the AC current of the nonlinear load, and the AC current of the rectifier through voltage Hall elements and current Hall elements;

[0196] A hysteresis current width and switching frequency acquisition module is used to obtain the hysteresis current width of the hysteresis control and the switching frequency of the SVPWM control according to the iTHD of the rectifier input current;

[0197] The AC current given value acquisition module is used to obtain the given value of the AC current of the PWM rectifier according to the AC current of the nonlinear load;

[0198] A switching pulse acquisition module of the hysteresis controller is used to select the hysteresis controller of the PWM rectifier according to the hysteresis current width of the hysteresis control to obtain the switching pulse of the hysteresis controller;

[0199] The switching pulse acquisition module of the SVPWM controller is used to select the SVPWM controller of the PWM rectifier according to the switching frequency of the SVPWM control and obtain the switching pulse of the SVPWM controller;

[0200] A current error maximum value acquisition module is used to obtain the current error maximum value according to the given value of the PWM rectifier AC current and the actual value of the PWM rectifier AC current;

[0201] The switching pulse acquisition module of the SVPWM controller is used to obtain the switching pulse of the hysteresis SVPWM controller according to the maximum current error and the switching width.

[0202] In one embodiment of the present invention, a computer device is provided, comprising a processor and a memory, wherein the memory is used to store a computer program, the computer program including program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of a PWM control method suitable for sudden current tracking.

[0203] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device, used to store programs and data. It is understood that the computer-readable storage medium herein may include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides storage space, which stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for being loaded and executed by a processor. These instructions may be one or more computer programs (including program code). It should be noted that the computer-readable storage medium herein may be a high-speed RAM memory or a non-volatile memory, such as at least one disk storage device. The processor may load and execute the one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the PWM control method suitable for sudden current tracking in the above-mentioned embodiment.

[0204] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0205] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0206] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0207] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0208] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PWM control method suitable for sudden current tracking, characterized in that: The following steps are involved: S1: Based on the input AC line voltage and input power of the rectifier, the input AC phase voltage, input current, output DC voltage, output DC power, and output DC current are obtained, and the connection inductance, connection resistance, output DC resistance, and output DC capacitance are calculated. S2: Collect the AC voltage of the grid, the DC voltage of the rectifier, the AC current of the grid, the AC current of the nonlinear load, and the AC current of the rectifier through voltage Hall elements and current Hall elements; S3: According to the iTHD of the rectifier input current, the hysteresis current width of the hysteresis control and the switching frequency of the SVPWM control are obtained; the hysteresis current width is: Among them, iTHD is the grid-side current harmonic distortion rate; H is the hysteresis current width; I a is the input current; The switching frequency of the SVPWM controller is: Where, L is the connection inductance; f is the switching frequency of the SVPWM controller; U dc is the output DC voltage; U a is the input AC phase voltage; S4: Obtain a given value of the PWM rectifier AC current according to the AC current of the nonlinear load; the harmonic current of the nonlinear load is: in, is the fundamental component of the load current; is the harmonic current of nonlinear load; i Labc is the AC current of the nonlinear load; The given value of the PWM rectifier AC current is: in, is the given value of the PWM rectifier AC current; S5: Selecting a hysteresis controller of the PWM rectifier according to the hysteresis current width of the hysteresis control to obtain a switching pulse of the hysteresis controller; S6: Selecting an SVPWM controller of the PWM rectifier according to the switching frequency of the SVPWM control to obtain a switching pulse of the SVPWM controller; S7: obtaining a maximum current error value according to a given value of the PWM rectifier AC current and an actual value of the PWM rectifier AC current; S8: Obtain the switching pulse of the hysteresis SVPWM controller according to the maximum current error and the switching width; the switching width of the PWM rectifier is: h=kH; Wherein, k is the switching coefficient, which is generally greater than 1, and generally ranges from 3 to 10, with a typical value of 6; h is the switching width of the PWM rectifier; The Schmitt switching width of the PWM rectifier is: dh=d*h; Where dh is the Schmitt switching width of the PWM rectifier; d is the Schmitt switching width coefficient. The input state of the RS trigger is obtained as follows: Wherein, k is the switching width coefficient; i Err is the current error of the PWM rectifier.

2. A PWM control method suitable for sudden current tracking according to claim 1, characterized in that: The input AC phase voltage is: Among them, U ab is the input AC line voltage; The input current is: Among them, P in is the power of the PWM rectifier; The connection inductance is: Among them, k l is the reactor coefficient, ω is the grid angular frequency; The connection resistance is: Where η is the system efficiency.

3. A PWM control method suitable for sudden current tracking according to claim 2, characterized in that: The output DC voltage is: IN dc =1.7U ab ; Among them, 1.7 is the boost coefficient; The output DC power is: P out =ηP in ; The output DC current is: The output DC resistance is: The output DC capacitance is: Among them, k c is the capacitor ripple factor.

4. The PWM control method for sudden current tracking according to claim 1, characterized in that: The absolute value of the current setpoint of the PWM rectifier is: The current error of the PWM rectifier is:

5. A rectifier hysteresis SVPWM control system suitable for sudden current tracking, characterized in that: A PWM control method suitable for sudden current tracking according to any one of claims 1 to 4, comprising: The DC parameter acquisition module is used to obtain the input AC phase voltage, input current, output DC voltage, output DC power, and output DC current according to the input AC line voltage and input power of the rectifier, and calculate the connection inductance, connection resistance, output DC resistance, and output DC capacitance; AC parameter acquisition module, used to collect the AC voltage of the power grid, the DC voltage of the rectifier, the AC current of the power grid, the AC current of the nonlinear load, and the AC current of the rectifier through voltage Hall elements and current Hall elements; A hysteresis current width and switching frequency acquisition module is used to obtain the hysteresis current width of the hysteresis control and the switching frequency of the SVPWM control according to the iTHD of the rectifier input current; The AC current given value acquisition module is used to obtain the given value of the AC current of the PWM rectifier according to the AC current of the nonlinear load; A switching pulse acquisition module of the hysteresis controller is used to select the hysteresis controller of the PWM rectifier according to the hysteresis current width of the hysteresis control to obtain the switching pulse of the hysteresis controller; The switching pulse acquisition module of the SVPWM controller is used to select the SVPWM controller of the PWM rectifier according to the switching frequency of the SVPWM control and obtain the switching pulse of the SVPWM controller; A current error maximum value acquisition module is used to obtain the current error maximum value according to the given value of the PWM rectifier AC current and the actual value of the PWM rectifier AC current; The switching pulse acquisition module of the SVPWM controller is used to obtain the switching pulse of the hysteresis SVPWM controller according to the maximum current error and the switching width.

6. A computer device 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 PWM control method suitable for sudden current tracking as claimed in any one of claims 1 to 4 are implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of a PWM control method suitable for sudden current tracking as claimed in any one of claims 1 to 4 are implemented.

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