Control method, system, device and storage medium of AC transmission converter

Abstract

The application discloses a control method, system and device of an AC transmission converter and a storage medium, and applies to the technical field of power electronics, and comprises the following steps: determining a fundamental frequency fb of a grid-side voltage and an interharmonic frequency fc to be suppressed; extracting a first DC voltage interharmonic and a second DC voltage interharmonic in a DC bus voltage, and deducting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage; taking the DC bus voltage obtained after the deduction of the first DC voltage interharmonic and the second DC voltage interharmonic as a DC bus voltage feedback quantity, and performing closed-loop feedback control on a rectifier in the AC transmission converter; wherein the frequency of the first DC voltage interharmonic is fb+fc, and the frequency of the second DC voltage interharmonic is fc-fb. By applying the scheme, the interharmonic can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a control method, system, device and storage medium for an AC drive converter. Background Art

[0002] With the continuous advancement of power electronics technology, AC drive converters using an AC-DC-AC topology with fully controlled components have been widely used in industries such as rail transit vehicles, renewable energy generation, and industrial transmission. During operation, AC drive converters produce not only harmonics that are integer multiples of the fundamental frequency, but also interharmonics that are non-integer multiples of the fundamental frequency. Interharmonics are often caused by voltage fluctuations or nonlinear loads. Examples include various variable-frequency speed control devices and induction motors, which are all sources of interharmonics.

[0003] Interharmonics are characterized by flicker and interference, which can cause equipment to malfunction or even damage in severe cases. Compared to integer harmonics, the impact and hazards of interharmonics have gradually attracted attention within the industry in recent years. For example, IEC61000-3-6 clearly defines the emission levels of interharmonics, and "Power Quality - Interharmonics in Public Grids" provides relevant regulations on the content, measurement methods, and accuracy of interharmonics. In the rail transit industry, because ground track circuit signal communication itself uses electrical signals with non-integer multiple frequencies for communication, there are more stringent standards for interharmonics in the grid-side current of rail transit vehicles.

[0004] In summary, how to effectively reduce interharmonics is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] The object of the present invention is to provide a control method, system, device and storage medium for an AC drive converter to effectively reduce interharmonics.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A control method for an AC drive converter, comprising:

[0008] Determine the fundamental frequency fb of the grid-side voltage and the interharmonic frequency fc to be suppressed;

[0009] Extracting a first DC voltage interharmonic and a second DC voltage interharmonic from the DC bus voltage, and subtracting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage;

[0010] The DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as a DC bus voltage feedback quantity to perform closed-loop feedback control of the rectifier in the AC drive converter;

[0011] The frequency of the first DC voltage interharmonic is fb+fc, and the frequency of the second DC voltage interharmonic is fc-fb.

[0012] Preferably, the DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as the DC bus voltage feedback amount to perform closed-loop feedback control of the rectifier in the AC drive converter, including:

[0013] The DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as the DC bus voltage feedback quantity, and closed-loop feedback control of the voltage outer loop and current inner loop of the rectifier in the AC drive converter is performed.

[0014] Preferably, when closed-loop feedback control is performed on the rectifier, the carrier used is a carrier on which the first DC voltage interharmonics and the second DC voltage interharmonics are superimposed.

[0015] Preferably, when closed-loop feedback control is performed on the rectifier, the modulation wave used is a modulation wave superimposed with the third DC voltage interharmonic and the fourth DC voltage interharmonic;

[0016] The third DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the first DC voltage interharmonic by a set coefficient, and the fourth DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the second DC voltage interharmonic by a set coefficient.

[0017] Preferably, the voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both high-interference immunity sensors.

[0018] Preferably, the voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both sensors with a signal link shielding layer grounded.

[0019] Preferably, it also includes:

[0020] When a first parameter adjustment instruction is received, the parameters of the closed-loop feedback control algorithm used by the rectifier are reduced according to the first parameter adjustment instruction.

[0021] Preferably, the extracting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage includes:

[0022] The first DC voltage interharmonic and the second DC voltage interharmonic in the DC bus voltage are extracted by a notch filter or a bandpass filter.

[0023] Preferably, it also includes:

[0024] Based on the collected DC bus voltage and inverter current, closed-loop feedback control of the inverter in the AC drive converter is performed according to a frequency adaptive proportional resonant control algorithm.

[0025] A control system for an AC drive converter, comprising:

[0026] The frequency determination module is used to determine the fundamental frequency fb of the outgoing voltage and the interharmonic frequency fc to be suppressed;

[0027] a DC bus voltage interharmonic suppression module, configured to extract a first DC voltage interharmonic and a second DC voltage interharmonic from the DC bus voltage, and deduct the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage;

[0028] a rectifier closed-loop feedback control module, configured to use the DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic as a DC bus voltage feedback quantity to perform closed-loop feedback control of the rectifier in the AC drive converter;

[0029] The frequency of the first DC voltage interharmonic is fb+fc, and the frequency of the second DC voltage interharmonic is fc-fb.

[0030] Preferably, the rectifier closed-loop feedback control module is specifically used to:

[0031] The DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as the DC bus voltage feedback quantity, and closed-loop feedback control of the voltage outer loop and current inner loop of the rectifier in the AC drive converter is performed.

[0032] Preferably, when closed-loop feedback control is performed on the rectifier, the carrier used is a carrier on which the first DC voltage interharmonics and the second DC voltage interharmonics are superimposed.

[0033] Preferably, when closed-loop feedback control is performed on the rectifier, the modulation wave used is a modulation wave superimposed with the third DC voltage interharmonic and the fourth DC voltage interharmonic;

[0034] The third DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the first DC voltage interharmonic by a set coefficient, and the fourth DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the second DC voltage interharmonic by a set coefficient.

[0035] A control device for an AC drive converter, comprising:

[0036] memory for storing computer programs;

[0037] A processor for executing the computer program to implement the steps of the AC drive converter control method as described above.

[0038] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the control method for an AC drive converter as described above.

[0039] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the control method for an AC drive converter as described above.

[0040] By applying the technical solution provided by the embodiments of the present invention, the grid-side voltage fundamental frequency fb and the interharmonic frequency fc to be suppressed are determined. The first DC voltage interharmonic fb+fc and the second DC voltage interharmonic fc-fb are then extracted from the DC bus voltage and subtracted from the DC bus voltage. This effectively suppresses the interharmonics from entering the rectifier's DC voltage control link during closed-loop feedback control of the rectifier in the AC drive converter. The resulting DC bus voltage after subtraction can be used as the DC bus voltage feedback variable for closed-loop feedback control of the rectifier in the AC drive converter.

[0041] In summary, the solution of the present application can effectively reduce interharmonics through the control of the AC drive converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a flow chart of an implementation method of a control method for an AC drive converter in the present invention;

[0044] Figure 2 This is a block diagram of the principle of DC voltage stability control for interharmonic suppression in a specific embodiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the classic circuit topology of the AC-DC-AC AC drive converter for rail transit vehicles;

[0046] Figure 4The figure is a schematic structural diagram of a control system of an AC drive converter in the present invention. DETAILED DESCRIPTION

[0047] The core of the present invention is to provide a control method for an AC drive converter, which can effectively reduce interharmonics.

[0048] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0049] Please refer to Figure 1 , Figure 1 This is a flow chart of an implementation method of a control method for an AC drive converter in the present invention. The control method for an AC drive converter may include the following steps:

[0050] Step S101: determining the fundamental frequency fb of the grid-side voltage and the interharmonic frequency fc to be suppressed.

[0051] Specifically, in this application's solution, interharmonics from the inverter are transmitted to the grid, requiring them to pass through the DC link circuit, causing DC voltage fluctuations before being transmitted to the grid. Improving the stability of the DC voltage through rectifier control can effectively reduce interharmonics.

[0052] By suppressing interharmonics from entering the DC voltage control link of the rectifier, the DC voltage stability control of the rectifier can be effectively achieved. Therefore, in the solution of the present application, it is necessary to determine the fundamental frequency fb of the grid-side voltage and the interharmonic frequency fc to be suppressed, so that in subsequent steps, the corresponding DC voltage interharmonics can be deducted to achieve the purpose of suppressing interharmonics from entering the DC voltage control link of the rectifier.

[0053] The fundamental frequency fb of the grid-side voltage can generally be determined by personnel, and the interharmonic frequency fc to be suppressed can also be determined by personnel. Furthermore, it is understood that in actual applications, there may be multiple interharmonic frequencies to be suppressed. In this case, the solution of the present application can be implemented for each interharmonic frequency to be suppressed, without affecting the implementation of the present invention.

[0054] Step S102: extracting a first DC voltage interharmonic and a second DC voltage interharmonic from the DC bus voltage, and subtracting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage.

[0055] After determining the fundamental frequency fb of the grid-side voltage and the interharmonic frequency fc to be suppressed, the first DC voltage interharmonic and the second DC voltage interharmonic need to be extracted before subtraction can be performed.

[0056] The frequency of the first DC voltage interharmonic described in this application is fb+fc, and the frequency of the second DC voltage interharmonic is fc-fb.

[0057] When extracting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC voltage signal, the extraction can be achieved using a notch filter or a bandpass filter. That is, in one specific embodiment of the present invention, extracting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage described in step S101 can include extracting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage using a notch filter or a bandpass filter.

[0058] For example, a notch filter with a center frequency of Fc+Fb or Fc-Fb, or a bandpass filter can be used to extract the interharmonics of the collected DC bus voltage. In practical applications, a notch filter is usually used for interharmonics in a narrow frequency band, while a bandpass filter is usually used for interharmonics in a wide frequency band. In addition, in practical applications, the amplitude and phase can be adjusted by adjusting the filter parameters to obtain the best interharmonic extraction effect. Figure 2 ,exist Figure 2 In the implementation manner, the first DC voltage interharmonic fb+fc and the second DC voltage interharmonic fc-fb are extracted from the collected DC bus voltage through two filters.

[0059] After extracting the first DC voltage interharmonic fb+fc and the second DC voltage interharmonic fc-fb, the first DC voltage interharmonic fb+fc and the second DC voltage interharmonic fc-fb can be subtracted from the DC bus voltage. That is, the first DC voltage interharmonic fb+fc and the second DC voltage interharmonic fc-fb are subtracted from the collected DC bus voltage. The subtraction result is used as the DC bus voltage feedback and then used in the DC voltage control link of the rectifier.

[0060] Step S103: using the DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic as a DC bus voltage feedback amount to perform closed-loop feedback control of the rectifier in the AC drive converter.

[0061] The first DC voltage interharmonic and the second DC voltage interharmonic in the collected DC bus voltage are deducted, that is, the difference between the collected DC bus voltage and the first DC voltage interharmonic and the second DC voltage interharmonic is calculated. The result is used as the DC bus voltage feedback amount, which can be used for closed-loop feedback control of the rectifier in the AC drive converter.

[0062] In practical applications, when performing closed-loop feedback control of a rectifier in an AC drive converter, dual-loop feedback control of a voltage outer loop and a current inner loop is generally adopted. That is, in a specific embodiment of the present invention, step S103 may specifically include:

[0063] The DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as the DC bus voltage feedback quantity, and closed-loop feedback control of the voltage outer loop and current inner loop of the rectifier in the AC drive converter is performed.

[0064] For details, please refer to Figure 2 When the closed-loop feedback control of the voltage outer loop and current inner loop is performed on the rectifier in the AC drive converter, the DC bus voltage feedback value is compared with the DC bus voltage target value. Figure 2 The DC bus voltage target is marked as Ud_set in the figure. The voltage outer loop is controlled based on the comparison result. The current output by the voltage outer loop is compared with the current target Ib. The current inner loop is controlled based on the comparison result. Finally, the rectifier is modulated based on the output of the current inner loop, that is, PWM (Pulse Width Modulation) pulses are generated to drive the rectifier.

[0065] In a specific embodiment of the present invention, when closed-loop feedback control is performed on the rectifier, the carrier used is a carrier superimposed with the first DC voltage interharmonic and the second DC voltage interharmonic.

[0066] In the aforementioned embodiment, the first and second DC voltage interharmonics are subtracted from the collected DC bus voltage to prevent interharmonics from entering the DC voltage control phase of the rectifier. This embodiment further considers that adding the first and second DC voltage interharmonics to the modulation phase of the rectifier can also further reduce interharmonics.

[0067] Specifically, after extracting the first DC voltage interharmonic and the second DC voltage interharmonic, the first DC voltage interharmonic and the second DC voltage interharmonic can be directly superimposed on the carrier, so that the rectifier carrier can be adjusted in real time with the interharmonic value, which is conducive to further reducing the interharmonic.

[0068] In a specific embodiment of the present invention, when closed-loop feedback control is performed on the rectifier, the modulation wave used is a modulation wave superimposed with the third DC voltage interharmonic and the fourth DC voltage interharmonic;

[0069] The third DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the first DC voltage interharmonic by a set coefficient, and the fourth DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the second DC voltage interharmonic by a set coefficient.

[0070] In the aforementioned embodiment, the first and second DC voltage interharmonics are directly superimposed on the carrier. This embodiment allows for the possibility of superimposing the first and second DC voltage interharmonics on the modulated wave, further reducing interharmonics. However, since the carrier peak corresponds to the DC voltage in the rectifier modulation link, and the first and second DC voltage interharmonics are also extracted from the DC voltage, they can be directly superimposed. The modulated wave corresponds to the AC side voltage in the rectifier modulation link, which is different from the first and second DC voltage interharmonics. Therefore, in this embodiment, it is necessary to first multiply the first DC voltage interharmonic by a set coefficient to obtain the third DC voltage interharmonic, and multiply the second DC voltage interharmonic by a set coefficient to obtain the fourth DC voltage interharmonic. These are then superimposed on the modulated wave, so that the rectifier's modulated wave is modulated in real time with the interharmonic values, further reducing interharmonics.

[0071] In a specific embodiment of the present invention, the voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both high-interference immunity sensors.

[0072] This implementation takes into account the fact that the inverter outputs a variable-frequency, variable-voltage voltage to drive the motor. Due to the high voltage and current, this can easily interfere with the various signal links of the AC-DC-AC converter. Typically, as the motor speed increases from zero to high speed, the fundamental frequency of the inverter current changes continuously. This continuously changing frequency is the interharmonic frequency of the grid-side fundamental. Therefore, the inverter current is subject to interharmonic interference that varies with speed.

[0073] When the inverter current interferes with the DC voltage signal, the collected DC bus voltage signal may be distorted, which in turn may cause interharmonics when adjusting the DC voltage. When the inverter current interferes with the rectifier current signal, the collected rectifier current signal may be distorted, which in turn may cause interharmonics when adjusting the rectifier current.

[0074] Therefore, in this embodiment, in order to avoid the interference of the inverter current, sensors with strong anti-interference ability are used for collecting the DC voltage signal and the rectifier current signal, that is, the voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both high-anti-interference sensors. Figure 3 , which is the classic circuit topology of the AC-DC-AC rail transit vehicle AC drive converter. Figure 3 The voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current can both be designed with high interference immunity sensors.

[0075] In addition, the voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current should be as far away from the main current line of the inverter current as possible to effectively avoid interference from the inverter current.

[0076] Furthermore, in one embodiment of the present invention, the voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both sensors with a grounded signal link shield. Specifically, the shield can be grounded individually or at both ends, thereby effectively preventing interference from the inverter current.

[0077] In a specific embodiment of the present invention, it may further include:

[0078] When the first parameter adjustment instruction is received, the parameters of the closed-loop feedback control algorithm used by the rectifier are reduced according to the first parameter adjustment instruction.

[0079] This implementation takes into account that the parameters of the rectifier's DC voltage control link, specifically the voltage outer loop, can affect the rectifier's control response. Excessively large parameters can easily amplify the DC voltage's interharmonics, leading to large interharmonics in the rectified current. Therefore, while meeting all control requirements, the DC voltage control parameters should be minimized.

[0080] In this regard, in this implementation, the staff can issue a first parameter adjustment instruction through the host computer. When the first parameter adjustment instruction is received, the parameters of the closed-loop feedback control algorithm used by the rectifier can be reduced according to the first parameter adjustment instruction, specifically referring to reducing the DC voltage control link, that is, reducing the parameters of the voltage outer loop.

[0081] In a specific embodiment of the present invention, it may further include:

[0082] Based on the collected DC bus voltage and inverter current, closed-loop feedback control of the inverter in the AC drive converter is performed according to a frequency adaptive proportional resonant control algorithm.

[0083] In the previous implementation, rectifier control was used to improve DC voltage stability, effectively reducing interharmonics. However, this implementation takes into account that the primary source of interharmonics is the nonlinear power disturbances of the inverter's output frequency conversion and voltage conversion. Therefore, interharmonic suppression can also be performed at the source, thereby improving inverter power stability.

[0084] When performing inverter power stability control, in this implementation, the DC bus voltage and inverter current are collected, and then the inverter is subjected to frequency adaptive proportional resonant control. That is, closed-loop feedback control of the inverter is performed according to the frequency adaptive proportional resonant control algorithm, thereby improving the sinusoidality of the inverter current, making the power stable, and effectively reducing interharmonics.

[0085] In addition, when collecting the DC bus voltage, real-time collection can be performed, thereby reducing the impact of random fluctuations in the intermediate DC voltage on the inverter pulse through pulse modulation of the inverter, thereby ensuring the stability of the inverter output power.

[0086] By applying the technical solution provided by the embodiments of the present invention, the grid-side voltage fundamental frequency fb and the interharmonic frequency fc to be suppressed are determined. The first DC voltage interharmonic fb+fc and the second DC voltage interharmonic fc-fb are then extracted from the DC bus voltage and subtracted from the DC bus voltage. This effectively suppresses the interharmonics from entering the rectifier's DC voltage control link during closed-loop feedback control of the rectifier in the AC drive converter. The resulting DC bus voltage after subtraction can be used as the DC bus voltage feedback variable for closed-loop feedback control of the rectifier in the AC drive converter.

[0087] In summary, the solution of the present application can effectively reduce interharmonics through the control of the AC drive converter.

[0088] Corresponding to the above method embodiment, an embodiment of the present invention further provides a control system for an AC drive converter, which can be referred to in correspondence with the above.

[0089] See also Figure 4 FIG. 1 is a schematic diagram of a control system of an AC drive converter according to the present invention, comprising:

[0090] The frequency determination module 401 is used to determine the fundamental frequency fb of the outgoing voltage and the interharmonic frequency fc to be suppressed;

[0091] a DC bus voltage interharmonic suppression module 402, configured to extract a first DC voltage interharmonic and a second DC voltage interharmonic from the DC bus voltage, and deduct the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage;

[0092] The rectifier closed-loop feedback control module 403 is configured to use the DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic as the DC bus voltage feedback amount to perform closed-loop feedback control of the rectifier in the AC drive converter;

[0093] The frequency of the first DC voltage interharmonic is fb+fc, and the frequency of the second DC voltage interharmonic is fc-fb.

[0094] In a specific embodiment of the present invention, the rectifier closed-loop feedback control module 403 is specifically configured to:

[0095] The DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as the DC bus voltage feedback quantity, and closed-loop feedback control of the voltage outer loop and current inner loop of the rectifier in the AC drive converter is performed.

[0096] In a specific embodiment of the present invention, when closed-loop feedback control is performed on the rectifier, the carrier used is a carrier superimposed with the first DC voltage interharmonic and the second DC voltage interharmonic.

[0097] In a specific embodiment of the present invention, when closed-loop feedback control is performed on the rectifier, the modulation wave used is a modulation wave superimposed with the third DC voltage interharmonic and the fourth DC voltage interharmonic;

[0098] The third DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the first DC voltage interharmonic by a set coefficient, and the fourth DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the second DC voltage interharmonic by a set coefficient.

[0099] In a specific embodiment of the present invention, the voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both high-interference immunity sensors.

[0100] In a specific embodiment of the present invention, the voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both sensors with a signal link shielding layer grounded.

[0101] In a specific embodiment of the present invention, a parameter adjustment module is further included, which is used to:

[0102] When the first parameter adjustment instruction is received, the parameters of the closed-loop feedback control algorithm used by the rectifier are reduced according to the first parameter adjustment instruction.

[0103] In a specific embodiment of the present invention, extracting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage includes:

[0104] The first DC voltage interharmonic and the second DC voltage interharmonic in the DC bus voltage are extracted by a notch filter or a bandpass filter.

[0105] In a specific embodiment of the present invention, an inverter closed-loop feedback control module is further included, which is used to:

[0106] Based on the collected DC bus voltage and inverter current, closed-loop feedback control of the inverter in the AC drive converter is performed according to a frequency adaptive proportional resonant control algorithm.

[0107] Corresponding to the above method and system embodiments, embodiments of the present invention further provide a control device for an AC drive converter and a computer-readable storage medium, which may refer to the above for their correspondence.

[0108] The control device of the AC drive converter may include:

[0109] memory for storing computer programs;

[0110] A processor is configured to execute a computer program to implement the steps of the method for controlling an AC drive converter in any of the above embodiments.

[0111] The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the control method for the AC drive converter in any of the above embodiments are implemented.

[0112] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0113] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may 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 invention.

[0114] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only intended to help understand the technical solutions and core concepts of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A control method for an AC drive converter, characterized in that: include: Determine the fundamental frequency fb of the grid-side voltage and the interharmonic frequency fc to be suppressed; Extracting a first DC voltage interharmonic and a second DC voltage interharmonic from the DC bus voltage, and subtracting the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage; The DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as a DC bus voltage feedback quantity to perform closed-loop feedback control of the rectifier in the AC drive converter; The frequency of the first DC voltage interharmonic is fb+fc, and the frequency of the second DC voltage interharmonic is fc-fb.

2. The control method of the AC drive converter according to claim 1, characterized in that: The method uses the DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic as the DC bus voltage feedback quantity to perform closed-loop feedback control of the rectifier in the AC drive converter, including: The DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as the DC bus voltage feedback quantity, and closed-loop feedback control of the voltage outer loop and current inner loop of the rectifier in the AC drive converter is performed.

3. The control method of the AC drive converter according to claim 2, characterized in that: When closed-loop feedback control is performed on the rectifier, the carrier used is a carrier on which the first DC voltage interharmonics and the second DC voltage interharmonics are superimposed.

4. The control method of the AC drive converter according to claim 2, characterized in that: When the closed-loop feedback control is performed on the rectifier, the modulation wave used is a modulation wave superimposed with the third DC voltage interharmonic and the fourth DC voltage interharmonic; The third DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the first DC voltage interharmonic by a set coefficient, and the fourth DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the second DC voltage interharmonic by a set coefficient.

5. The control method of the AC drive converter according to claim 2, characterized in that: The voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both high-interference-immunity sensors.

6. The control method of the AC drive converter according to claim 5, characterized in that: The voltage sensor used to collect the DC bus voltage and the current sensor used to collect the rectifier current are both sensors with the signal link shielding layer grounded.

7. The control method of the AC drive converter according to claim 1, characterized in that: Also includes: When a first parameter adjustment instruction is received, the parameters of the closed-loop feedback control algorithm used by the rectifier are reduced according to the first parameter adjustment instruction.

8. The control method of the AC drive converter according to claim 1, characterized in that: The extracting of the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage includes: The first DC voltage interharmonic and the second DC voltage interharmonic in the DC bus voltage are extracted by a notch filter or a bandpass filter.

9. The control method of an AC drive converter according to any one of claims 1 to 8, characterized in that: Also includes: Based on the collected DC bus voltage and inverter current, closed-loop feedback control of the inverter in the AC drive converter is performed according to a frequency adaptive proportional resonant control algorithm.

10. A control system for an AC drive converter, characterized in that: include: The frequency determination module is used to determine the fundamental frequency fb of the outgoing voltage and the interharmonic frequency fc to be suppressed; a DC bus voltage interharmonic suppression module, configured to extract a first DC voltage interharmonic and a second DC voltage interharmonic from the DC bus voltage, and deduct the first DC voltage interharmonic and the second DC voltage interharmonic from the DC bus voltage; a rectifier closed-loop feedback control module, configured to use the DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic as a DC bus voltage feedback quantity to perform closed-loop feedback control of the rectifier in the AC drive converter; The frequency of the first DC voltage interharmonic is fb+fc, and the frequency of the second DC voltage interharmonic is fc-fb.

11. The control system of the AC drive converter according to claim 10, characterized in that: The rectifier closed-loop feedback control module is specifically used to: The DC bus voltage obtained after deducting the first DC voltage interharmonic and the second DC voltage interharmonic is used as the DC bus voltage feedback quantity, and closed-loop feedback control of the voltage outer loop and current inner loop of the rectifier in the AC drive converter is performed.

12. The control system of the AC drive converter according to claim 11, characterized in that: When closed-loop feedback control is performed on the rectifier, the carrier used is a carrier on which the first DC voltage interharmonics and the second DC voltage interharmonics are superimposed.

13. The control system of the AC drive converter according to claim 11, characterized in that: When the closed-loop feedback control is performed on the rectifier, the modulation wave used is a modulation wave superimposed with the third DC voltage interharmonic and the fourth DC voltage interharmonic; The third DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the first DC voltage interharmonic by a set coefficient, and the fourth DC voltage interharmonic is a DC voltage interharmonic obtained by multiplying the second DC voltage interharmonic by a set coefficient.

14. A control device for an AC drive converter, characterized in that: include: Memory for storing computer programs; A processor is configured to execute the computer program to implement the steps of the method for controlling the AC drive converter according to any one of claims 1 to 9.

15. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the control method of the AC drive converter according to any one of claims 1 to 9 are implemented.

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