A rectification control method and system, electronic equipment and readable storage medium

Abstract

The application discloses a rectification control method and system, electronic equipment and a readable storage medium, and relates to the field of power electronics. The method comprises the following steps: obtaining actual inter-harmonic current of a preset frequency in grid-side current of a rectifier; correcting the actual inter-harmonic current according to a preset phase angle offset to obtain corrected inter-harmonic current corresponding to a phase angle of a current modulation wave voltage of the rectifier; and adjusting the current modulation wave voltage according to the corrected inter-harmonic current and controlling the rectifier according to the current modulation wave voltage to reduce the actual inter-harmonic current in the grid-side current. According to the application, the inter-harmonic current in the grid-side current is extracted and corrected, and then the corrected inter-harmonic current is used as the basis for adjusting the modulation wave voltage, so that the closed-loop feedback of the inter-harmonic current is realized. Through the closed-loop feedback, the content of the actual inter-harmonic current in the grid-side current output by the rectifier after rectification according to the modulation wave voltage is reduced, and thus the influence of the inter-harmonic current on the performance of the system equipment is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power electronics, in particular to a rectification control method and system, electronic equipment and readable storage medium. BACKGROUND

[0002] With the development of power electronics technology, AC drive converters using full-controlled devices have been widely used in rail transit vehicles, new energy power generation, industrial transmission and other industries. The converter using power electronic devices not only has integer harmonics, but also has interharmonics. Interharmonics are often caused by voltage fluctuations or nonlinear loads. All nonlinear or fluctuating loads, such as various frequency conversion speed regulation devices, induction motors, etc., are interharmonic sources.

[0003] When the interharmonic is large, the network side current of the rectifier is distorted, which will cause the performance of each device to decline, and in severe cases, it will cause the device to malfunction, and even cause damage. Especially in the rail transit industry, when the interharmonic of the network side current of the AC drive system of the rail transit vehicle is too large, it is difficult to meet the requirements of various standards, and in severe cases, it will interfere with the ground track circuit signal communication, thereby affecting the normal operation of the rail transit vehicle.

[0004] In recent years, the influence and harm of interharmonics have gradually attracted attention in the industry. In the field of rail transit, since the ground track circuit signal communication itself uses non-integer frequency electrical signals for communication, the interharmonic of the network side current of the rail transit vehicle (locomotive, motor train unit, etc.) has more stringent standards. The TSI / ERA / ERTMS / 033281 standard of the European Union railway, NNTR, etc. have made relevant limit requirements for rail transit vehicles.

[0005] However, at present, there is no mature and effective technical solution in the field of rail transit on how to reduce and eliminate the interharmonic of the network side current, and the interharmonic content of the network side current in the current power electronic control scheme of the rail transit vehicle is still high.

[0006] Therefore, how to provide a scheme to solve the above technical problems is a problem that needs to be solved by the technical personnel in the field at present. SUMMARY

[0007] Therefore, the purpose of the present application is to provide a rectification control method and system for reducing interharmonics, electronic equipment and readable storage medium. The specific scheme is as follows:

[0008] A rectification control method, comprising:

[0009] obtaining the actual interharmonic current of a predetermined frequency in the network side current of the rectifier;

[0010] correcting the actual inter-harmonic current according to a preset phase angle offset, to obtain a corrected inter-harmonic current corresponding to a phase angle of a current modulation wave voltage of the rectifier;

[0011] adjusting the current modulation wave voltage according to the corrected inter-harmonic current, and controlling the rectifier according to the current modulation wave voltage, to eliminate the actual inter-harmonic current in the grid-side current.

[0012] Preferably, the process of obtaining the actual inter-harmonic current of a preset frequency in the grid-side current of the rectifier comprises:

[0013] obtaining the actual inter-harmonic current of the preset frequency in the grid-side current of the rectifier by a notch filter.

[0014] Preferably, the preset phase angle offset comprises:

[0015] a first phase angle offset between the current modulation wave voltage and the actual inter-harmonic current, and / or a second phase angle offset generated by the notch filter when obtaining the actual inter-harmonic current.

[0016] Preferably, the process of adjusting the current modulation wave voltage according to the corrected inter-harmonic current comprises:

[0017] subtracting a reference inter-harmonic current set value from the corrected inter-harmonic current to obtain an inter-harmonic voltage;

[0018] updating the current modulation wave voltage to a superposition of an opposite value of the inter-harmonic voltage and the current modulation wave voltage.

[0019] Preferably, the process of adjusting the current modulation wave voltage according to the corrected inter-harmonic current comprises:

[0020] multiplying the corrected inter-harmonic current by a preset proportional coefficient to obtain an inter-harmonic voltage;

[0021] updating the current modulation wave voltage to a superposition of an opposite value of the inter-harmonic voltage and the current modulation wave voltage.

[0022] Preferably, the process of controlling the rectifier according to the current modulation wave voltage comprises:

[0023] raising a carrier frequency of the rectifier from a current carrier frequency to a preset carrier frequency, the preset carrier frequency being not less than the current carrier frequency;

[0024] generating a desired action time of each switch in the rectifier according to the current modulation wave voltage and the preset carrier frequency;

[0025] According to the dead-time length of the switch in the rectifier and the expected action time, a corresponding dead-time compensation is performed on the dead-time to obtain an instruction action time;

[0026] According to all the instruction action times, the corresponding switches in the rectifier are controlled.

[0027] Preferably, before the current modulation wave voltage is controlled, the method further comprises:

[0028] The carrier phase shift angle of the rectifier is set as (π / N+α), where N is a positive integer, representing the number of all the rectifiers, and α is a preset deviation angle.

[0029] Preferably, the rectification control method further comprises:

[0030] The grid-side current is filtered by a filter winding;

[0031] The filter winding is a transformer winding on the same side of the rectifier.

[0032] Preferably, the process of correcting the actual inter-harmonic current according to the preset phase angle offset to obtain a corrected inter-harmonic current corresponding to the phase angle of the current modulation wave voltage of the rectifier comprises:

[0033] The actual phase angle of the actual inter-harmonic current is offset by a preset phase angle offset to obtain a corrected inter-harmonic current corresponding to the phase angle of the current modulation wave voltage of the rectifier.

[0034] Preferably, before the current modulation wave voltage is adjusted according to the corrected inter-harmonic current and the rectifier is controlled according to the current modulation wave voltage to reduce the actual inter-harmonic current in the grid-side current, the method further comprises:

[0035] According to the actual current, the actual intermediate voltage and the reference intermediate voltage of the rectifier, the current modulation wave voltage is determined by a double closed-loop control strategy.

[0036] Preferably, when the current loop control in the double closed-loop control strategy is PI control, the proportional coefficient of the PI control is the minimum value that meets a preset response condition.

[0037] Preferably, when the current loop control in the double closed-loop control strategy is PR control, in the control parameters of the PR control, the proportional coefficient is the minimum value that meets a preset response condition, and / or the resonance coefficient is the maximum value that meets the preset response condition, and / or the cutoff frequency is the minimum value that meets the preset response condition.

[0038] Correspondingly, the application also discloses a rectification control system, comprising:

[0039] The acquisition module is configured to acquire an actual inter-harmonic current of a preset frequency in a grid-side current of the rectifier.

[0040] The correction module is configured to perform phase angle correction on the actual inter-harmonic current according to a preset phase angle offset, to obtain a corrected inter-harmonic current corresponding to a phase angle of a current modulation wave voltage of the rectifier.

[0041] The adjustment module is configured to adjust the current modulation wave voltage according to the corrected inter-harmonic current, and control the rectifier according to the current modulation wave voltage, to reduce the actual inter-harmonic current in the grid-side current.

[0042] Correspondingly, the application also discloses an electronic device, which comprises:

[0043] The memory is configured to store a computer program.

[0044] The processor is configured to implement the steps of the rectifier control method according to any one of the above when the computer program is executed.

[0045] Correspondingly, the application also discloses a readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the rectifier control method according to any one of the above.

[0046] The application extracts and corrects the inter-harmonic current in the grid-side current, and then uses the corrected inter-harmonic current as the adjustment basis of the modulation wave voltage, so that the content of the actual inter-harmonic current in the grid-side current output by the rectifier after rectification according to the modulation wave voltage is reduced, and the influence of the inter-harmonic current on the performance of the system equipment is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only belong to the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0048] Figure 1 The flow chart of the steps of the rectifier control method in the embodiment of the present application;

[0049] Figure 2 The bode diagram of the trap filter in the embodiment of the present application;

[0050] Figure 3 The bode diagram of the phase-corrected inter-harmonic current in the embodiment of the present application;

[0051] Figure 4 A control principle diagram of one double closed-loop control strategy in the embodiment of the present application;

[0052] Figure 5 A control principle diagram of one specific double closed-loop control strategy in the embodiment of the present application;

[0053] Figure 6 A control principle diagram of another specific double closed-loop control strategy in the embodiment of the present application;

[0054] Figure 7 A structure distribution diagram of one rectification control system in the embodiment of the present application. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0056] Currently, there is no mature and effective technical solution for how to reduce and eliminate the interharmonic of the grid-side current in the field of rail transit. The content of the interharmonic of the grid-side current in the current power electronic control scheme of the rail transit vehicle is still high.

[0057] The present application extracts and corrects the interharmonic current in the grid-side current, and takes it as the adjustment basis of the modulated wave voltage, realizes the closed-loop feedback of the interharmonic current, and reduces the content of the actual interharmonic current in the grid-side current output by the rectifier according to the modulated wave voltage, thereby reducing the performance influence of the interharmonic on the system equipment.

[0058] The embodiment of the present application discloses a rectification control method, referring to Figure 1 as shown, comprising:

[0059] S1: obtaining the actual interharmonic current of a preset frequency in the grid-side current of the rectifier;

[0060] It can be understood that the actual interharmonic current can be obtained by a notch filter or a band-pass filter with the preset frequency as the center frequency, wherein the notch filter is suitable for narrow-band interharmonic, and the band-pass filter is suitable for wide-band interharmonic. By adjusting the notch filter or the band-pass filter, the best interharmonic extraction effect can be realized, and the instantaneous current of the actual interharmonic current of the preset frequency is obtained. Therefore, step S1 can include: obtaining the actual interharmonic current of the preset frequency in the grid-side current of the rectifier by the notch filter.

[0061] For example, Figure 2 As shown in a bode diagram of one example, Figure 2 As shown in a bode diagram of one example, the center frequency of the notch filter is 73.03, and when the preset frequency is near the center frequency, the notch filter of Figure 2 may be used to obtain the actual inter-harmonic current of the preset frequency.

[0062] S2: According to the preset phase angle offset, the actual inter-harmonic current is phase angle corrected to obtain a corrected inter-harmonic current corresponding to the phase angle of the current modulation wave voltage of the rectifier;

[0063] The preset phase angle offset includes a first phase angle offset between the modulation wave voltage and the actual inter-harmonic current, and / or a second phase angle offset generated by the notch filter when obtaining the actual inter-harmonic current.

[0064] It can be understood that step S2 specifically includes offsetting the actual phase angle of the actual inter-harmonic current by the preset phase angle offset to obtain the corrected inter-harmonic current corresponding to the phase angle of the current modulation wave voltage of the rectifier. Further, the direction of the actual phase angle offset includes forward and backward, and the specific direction can be determined according to the signs of the first phase angle offset and the second phase angle offset, such as Figure 3 As shown in a bode diagram of one example, the actual inter-harmonic current and the corrected inter-harmonic current after phase angle correction are compared, and in this example, the corrected inter-harmonic current is the result of the actual inter-harmonic current being offset backward by the preset phase angle offset. It can be understood that Figure 3 Only as an example, the direction of the actual phase angle offset needs to be determined according to the actual situation, which is not limited here.

[0065] S3: Adjusting the current modulation wave voltage according to the corrected inter-harmonic current and controlling the rectifier according to the current modulation wave voltage to reduce the actual inter-harmonic current in the grid-side current.

[0066] It can be understood that in the present embodiment, the current modulation wave voltage is determined by a control strategy according to the actual current of the rectifier, the actual intermediate voltage and the reference intermediate voltage. The control strategy can usually be selected as a double closed-loop control strategy, and the mainstream control strategies include transient current control, D-Q current decoupling control, predictive current control, etc. Taking the transient current control as an example, the control principle diagram of the double closed-loop control strategy is shown in Figure 4 ref The reference intermediate voltage is the specified intermediate voltage, the actual intermediate voltage is U dc , the specified current obtained by intermediate voltage closed-loop control is i dref , the actual input current is i N , and the actual input current is i p ​The initial modulated wave voltage obtained through input current closed-loop control is used to output the modulated wave u after passing through an adder. c The modulated wave is input into the PWM modulation module to obtain a pulse signal used to control the switching action of the rectifier.

[0067] There are two methods to adjust the current modulation voltage based on the corrected interharmonic current. One method is to add an interharmonic suppression closed-loop control loop. With the reference interharmonic current setpoint as 0, the interharmonic voltage is obtained using closed-loop control such as PR control or PI control. The interharmonic voltage is then superimposed on the current modulation voltage, allowing the rectifier's current modulation voltage to be adjusted in real time with the value of the corrected interharmonic current, thereby reducing the content of actual interharmonic current in the subsequent grid-side current. The other method is to use the result of multiplying the corrected interharmonic current by a preset proportional coefficient as the interharmonic voltage. This interharmonic voltage is then superimposed on the current modulation voltage, allowing the rectifier's current modulation voltage to be adjusted in real time with the value of the corrected interharmonic current, thereby reducing the content of actual interharmonic current in the subsequent grid-side current.

[0068] Therefore, step S3, which involves adjusting the current modulation voltage based on the corrected interharmonic current, may specifically include:

[0069] The interharmonic voltage is obtained by subtracting the reference interharmonic current setpoint from the corrected interharmonic current and then performing closed-loop control.

[0070] Update the current modulated wave voltage to the superposition of the opposite value of the interharmonic voltage and the current modulated wave voltage.

[0071] like Figure 5 As shown, i Nfilter To correct the interharmonics, the reference interharmonic current setting is set to 0, and the output interharmonic voltage u is adjusted after closed-loop control. f The interharmonic voltage is compared with the initial modulation voltage u. p The updated modulation voltage u is obtained through adders and subtractors. c It is understandable that without the superposition of interharmonic voltages, the initial modulating voltage u p With the modulation voltage u used for PWM modulation c They are equal, therefore the initial modulation wave voltage u p In reality, it is the current modulation wave voltage that has not been updated.

[0072] Alternatively, step S3, which involves adjusting the current modulation voltage based on the corrected interharmonic current, may specifically include:

[0073] The result of multiplying the corrected interharmonic current by the preset proportional coefficient is taken as the interharmonic voltage.

[0074] Update the current modulated wave voltage to the superposition of the opposite value of the interharmonic voltage and the current modulated wave voltage.

[0075] like Figure 6 As shown, i Nfilter To correct the interharmonics, a preset proportional coefficient of K1 is used. After multiplication, the output interharmonic voltage u is calculated. f The interharmonic voltage is compared with the initial modulation voltage u. p The updated modulation voltage u is obtained through adders and subtractors. c .

[0076] Understandably, after updating the current modulation voltage, a pulse is generated by PWM modulation based on the updated modulation voltage. This pulse controls the switching action in the rectifier, thereby causing the rectifier to output a corresponding grid-side current. When the current modulation voltage is not updated, the actual interharmonic current content in the grid-side current is relatively high. After updating the current modulation voltage, the actual interharmonic current content in the grid-side current output by the rectifier is significantly reduced.

[0077] This application extracts and corrects the interharmonic current in the grid-side current and uses it as the basis for adjusting the modulation wave voltage, thereby realizing closed-loop feedback of the interharmonic current. Through this closed-loop feedback, the content of the actual interharmonic current in the grid-side current output by the rectifier after rectification according to the modulation wave voltage is reduced, thereby reducing the impact of interharmonics on the performance of system equipment.

[0078] This invention discloses a specific rectification control method. Compared with the previous embodiment, this embodiment further explains and optimizes the technical solution. Specifically, in order to reduce the content of interharmonic current, other technical measures can be further added, such as improving the grid-side current quality, adjusting the grid-side current harmonic distribution, and filtering out specific interharmonics.

[0079] It is understandable that, in order to further reduce the content of actual interharmonic current in the grid-side current, in addition to the closed-loop feedback of interharmonic current used in step S3, the parameters of the rectifier control can be adjusted to make the grid-side current closer to a sine wave and improve the quality of the grid-side current, thereby reducing the interharmonic content. Specific adjustment methods include increasing the carrier frequency, shortening the dead time, and performing dead time compensation. Therefore, the process of controlling the rectifier according to the current modulation wave voltage can include:

[0080] Increase the carrier frequency of the rectifier from the current carrier frequency to a preset carrier frequency, where the preset carrier frequency is not less than the current carrier frequency;

[0081] Based on the current modulation wave voltage and the preset carrier frequency, the desired operating time for each switch in the rectifier is generated;

[0082] According to the dead-time length requirement of the switch in the rectifier and the expected action time, the corresponding dead-time is compensated in advance to obtain the instruction action time;

[0083] According to all the instruction action times, the corresponding switches in the rectifier are controlled.

[0084] It can be understood that, generally, for the application of the dead-time length requirement, the instruction action time is obtained by delaying the corresponding dead-time length at the expected action time. This method can easily lead to the loss of the pulse signal of the PWM modulation, so that the actual output switch pulse voltage is partially lost, and the net-side current waveform is distorted, resulting in an increase in the inter-harmonic. Therefore, in the embodiment, the expected action time is advanced according to the dead-time length requirement, that is, the instruction action time is obtained by performing dead-time compensation in advance. The actual action time of the switch after receiving the control instruction, that is, the process of the switch action, will be closer to the expected action time even if it is affected by the dead-time. When the actual action time of all the switches is close to the expected action time, the pulse integrity is higher, and the net-side current of the rectifier will be closer to the sine wave corresponding to the expected action time, so that the current quality is improved and the harmonic content is reduced.

[0085] Correspondingly, the carrier frequency improvement makes the switch frequency improve, which can make the harmonic move to a higher frequency, and the harmonic value tends to decrease, thereby achieving the effect of reducing the inter-harmonic. It can be understood that, only increasing the switch frequency without adjusting the action time of the switch will lead to an increase in the low-order harmonic, which may increase the inter-harmonic content. Therefore, the switch frequency and the advance of the switch action time according to the dead-time length requirement should be used in combination, so as to effectively improve the current quality and reduce the inter-harmonic content.

[0086] Further, for the multi-PWM rectifier, the carrier phase shift can improve the lowest harmonic rate of the net-side current, thereby improving the harmonic characteristics of the grid current. Therefore, before controlling the rectifier according to the current modulation wave voltage, the following steps can be further included:

[0087] The carrier phase shift angle of the rectifier is set to (π / N+α), where N is a positive integer, representing the number of all rectifiers, and α is a preset deviation angle.

[0088] Further, the interharmonic current component in the grid-side current can be filtered out by a reasonable filter circuit, the filter circuit including a reasonable capacitor, and / or inductor, and / or resistor, the filter circuit being usually provided in the form of a filter winding on the circuit between the transformer and the rectifier, the filter winding being directly connected in series on the connection path between the side winding of the transformer and the grid side of the rectifier, or the filter circuit being connected in parallel with the side winding of the transformer, and the position of the filter winding and the element parameters can be selected according to the working condition and actual demand.

[0089] filtering the grid-side current through the filter winding;

[0090] the filter winding is a transformer winding on the same side of the rectifier.

[0091] The embodiment of the application discloses a specific rectifier control method, and further describes and optimizes the technical solution compared with the previous embodiment. Specifically, the current modulation wave voltage is adjusted according to the corrected interharmonic current, and the rectifier is controlled according to the current modulation wave voltage, and before the actual interharmonic current in the grid-side current is reduced, the method further includes: determining the current modulation wave voltage through a double closed-loop control strategy according to the actual current of the rectifier, the actual intermediate voltage and the reference intermediate voltage.

[0092] Further, the double closed-loop control strategy can be further optimized for the purpose of eliminating interharmonics. Specifically, the control parameter of the current loop affects the response of the rectifier control. If the control parameter of the current loop is too large, the current loop is easy to amplify the interharmonic of the grid-side current. However, as the inner loop, the current loop is used to make the grid-side current quickly follow the current instruction, ensure the sinusoidal degree of the current, and improve the dynamic response of the converter, so the parameter of the current loop should not be too small. Therefore, the control parameter of the current loop needs to be properly adjusted. That is, the control demand is met, and the current interharmonic is reduced.

[0093] Specifically, when the current loop control in the double closed-loop control strategy is PI control, the transfer function GPI is:

[0094]

[0095] wherein K is a proportional coefficient, and T is a time constant.

[0096] When the control parameter of the current loop is optimized, the proportional coefficient is mainly optimized. Specifically, the optimization target can be selected as the minimum value of the proportional coefficient of the PI control that meets the preset response condition.

[0097] Similarly, when the current loop control in the double closed-loop control strategy is PR control, the transfer function G quasi-PR (s) is specifically:

[0098]

[0099] wherein k is a proportional coefficient p proportional coefficient, k r ω is a resonance coefficient r ω is a resonance frequency c ω is a cutoff frequency.

[0100] It can be understood that the values of the control parameters are different, the influence on the amplitude-frequency characteristic of the current loop controller is also different, specifically, the proportional coefficient influences the amplitude gain of the base frequency and other frequency bands, and the two are in a positive correlation relationship; the resonance coefficient determines the gain at the base frequency; the cutoff frequency influences the bandwidth of the controller, the larger the cutoff frequency, the higher the system bandwidth, and the gain near the resonance frequency also increases accordingly, both the gain and the bandwidth should be considered, and the cutoff frequency should be reasonably selected. Selecting reasonable parameters can suppress interharmonics through the characteristics of the PR controller, therefore, the parameter setting should ensure that the gain at the base frequency is large and the frequency bands outside the base frequency can rapidly decay, to ensure that the interharmonics can be weakened in the current loop control part, and the specific optimization target can be selected as: in the control parameters of the PR control, the proportional coefficient is the minimum value that meets the preset response condition, and / or, the resonance coefficient is the maximum value that meets the preset response condition, and / or, the cutoff frequency is the minimum value that meets the preset response condition. Specifically, the values of the parameters can be selected as: the proportional coefficient is 2, the resonance coefficient is 5, and the cutoff frequency is 1.

[0101] Correspondingly, the application also discloses a rectification control system, referring to Figure 7 as shown, comprising:

[0102] An acquisition module 1 is configured to acquire actual interharmonic current of a preset frequency in a grid-side current of a rectifier.

[0103] A correction module 2 is configured to perform phase angle correction on the actual interharmonic current according to a preset phase angle offset, to obtain corrected interharmonic current corresponding to a phase angle of a current modulation wave voltage of the rectifier.

[0104] An adjustment module 3 is configured to adjust the current modulation wave voltage according to the corrected interharmonic current, and control the rectifier according to the current modulation wave voltage, to reduce the actual interharmonic current in the grid-side current.

[0105] The application extracts and corrects the interharmonic current in the grid-side current, and takes the corrected interharmonic current as the basis for adjusting the modulation wave voltage, to realize closed-loop feedback of the interharmonic current, through the closed-loop feedback, the content of the actual interharmonic current in the grid-side current output by the rectifier after rectification according to the modulation wave voltage is reduced, thereby reducing the influence of the interharmonic on the performance of the system equipment.

[0106] In some specific embodiments, the process of obtaining the actual inter-harmonic current of the preset frequency in the grid-side current of the rectifier comprises:

[0107] The actual inter-harmonic current of the preset frequency in the grid-side current of the rectifier is obtained by the notch filter.

[0108] In some specific embodiments, the preset phase angle offset comprises:

[0109] The first phase angle offset between the current modulation wave voltage and the actual inter-harmonic current, and / or the second phase angle offset generated by the notch filter when obtaining the actual inter-harmonic current.

[0110] In some specific embodiments, the process of adjusting the current modulation wave voltage according to the corrected inter-harmonic current comprises:

[0111] The reference inter-harmonic current set value is subtracted from the corrected inter-harmonic current to obtain an inter-harmonic voltage through closed-loop control.

[0112] The current modulation wave voltage is updated to the superposition of the opposite value of the inter-harmonic voltage and the current modulation wave voltage.

[0113] In some specific embodiments, the process of adjusting the current modulation wave voltage according to the corrected inter-harmonic current comprises:

[0114] The result of multiplying the corrected inter-harmonic current by a preset proportionality coefficient is taken as an inter-harmonic voltage.

[0115] The current modulation wave voltage is updated to the superposition of the opposite value of the inter-harmonic voltage and the current modulation wave voltage.

[0116] In some specific embodiments, the process of controlling the rectifier according to the current modulation wave voltage comprises:

[0117] The carrier frequency of the rectifier is raised from a current carrier frequency to a preset carrier frequency, and the preset carrier frequency is not less than the current carrier frequency.

[0118] According to the current modulation wave voltage and the preset carrier frequency, the expected action time of each switch in the rectifier is generated.

[0119] According to the dead time length of the switch in the rectifier and the expected action time, the corresponding dead time is compensated in advance to obtain an instruction action time.

[0120] According to all the instruction action times, the corresponding switches in the rectifier are controlled.

[0121] In some specific embodiments, before the adjusting module 3 controls the rectifier according to the current modulation wave voltage, the adjusting module 3 is further configured to:

[0122] set a carrier phase shift angle of the rectifier as (π / N+α), where N is a positive integer, representing the number of all the rectifiers, and α is a preset deviation angle.

[0123] In some specific embodiments, the rectifier control system further comprises a filtering module configured to:

[0124] filter the grid-side current through a filtering winding;

[0125] the filtering winding is a transformer winding on the same side as the rectifier.

[0126] In some specific embodiments, the process of phase angle correction of the actual inter-harmonic current according to a preset phase angle offset, to obtain a corrected inter-harmonic current corresponding to a phase angle of the current modulation wave voltage of the rectifier, comprises:

[0127] offset the actual phase angle of the actual inter-harmonic current by a preset phase angle offset, to obtain a corrected inter-harmonic current corresponding to a phase angle of the current modulation wave voltage of the rectifier.

[0128] In some specific embodiments, before the current modulation wave voltage is adjusted according to the corrected inter-harmonic current and the rectifier is controlled according to the current modulation wave voltage to eliminate the actual inter-harmonic current in the grid-side current, the process further comprises:

[0129] determining the current modulation wave voltage through a double-loop control strategy according to the actual current, the actual intermediate voltage and the reference intermediate voltage of the rectifier.

[0130] In some specific embodiments, when the current loop control in the double-loop control strategy is PI control, the proportional coefficient of the PI control is the minimum value that meets a preset response condition.

[0131] In some specific embodiments, when the current loop control in the double-loop control strategy is PR control, in the control parameters of the PR control, the proportional coefficient is the minimum value that meets a preset response condition, and / or the resonance coefficient is the maximum value that meets the preset response condition, and / or the cutoff frequency is the minimum value that meets the preset response condition.

[0132] Correspondingly, the application also discloses an electronic device, comprising:

[0133] a memory configured to store a computer program;

[0134] A processor configured to implement the steps of the commutation control method as described in any one of the above embodiments when the computer program is executed by the processor.

[0135] Accordingly, the application also discloses a readable storage medium, wherein the readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the commutation control method as described in any one of the above embodiments.

[0136] In the embodiment, details of the commutation control method can refer to the above description, and will not be described here.

[0137] In the embodiment, the electronic device and the readable storage medium have the same technical effects as the commutation control method in the above embodiment, and will not be described here.

[0138] Finally, it should be noted that, in this document, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0139] The above describes in detail the commutation control method, system, electronic device and readable storage medium provided by the application. In this document, the principles and implementation manners of the application are described by applying specific examples. The above description of the embodiments is only used to help understand the method of the application and its core idea; meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manner and application range will be changed, and the above description should not be understood as the limitation of the application.

Claims

1. A rectification control method characterized by, The method comprises: acquiring actual harmonic current of a preset frequency in grid-side current of a rectifier; phase angle correcting the actual harmonic current according to a preset phase angle offset to obtain corrected harmonic current corresponding to a phase angle of a current modulation wave voltage of the rectifier; subtracting a reference harmonic current setting value from the corrected harmonic current to obtain a harmonic voltage through closed-loop control, and / or multiplying the corrected harmonic current by a preset proportional coefficient to obtain a harmonic voltage; updating the current modulation wave voltage to a superposition of an opposite value of the harmonic voltage and the current modulation wave voltage to eliminate the actual harmonic current in the grid-side current; the preset phase angle offset comprises a first phase angle offset between the modulation wave voltage and the actual harmonic current, and / or a second phase angle offset generated by a notch filter when acquiring the actual harmonic current.

2. The rectifier control method of claim 1, wherein The process of acquiring the actual harmonic current of the preset frequency in the grid-side current of the rectifier comprises: acquiring the actual harmonic current of the preset frequency in the grid-side current of the rectifier through a notch filter.

3. The rectifier control method of claim 2, wherein The preset phase angle offset comprises: a first phase angle offset between the current modulation wave voltage and the actual harmonic current, and / or a second phase angle offset generated by the notch filter when acquiring the actual harmonic current.

4. The rectifier control method of claim 1, wherein The process of controlling the rectifier according to the current modulation wave voltage comprises: raising a carrier frequency of the rectifier from a current carrier frequency to a preset carrier frequency, the preset carrier frequency being not less than the current carrier frequency; generating a desired action time of each switch in the rectifier according to the current modulation wave voltage and the preset carrier frequency; carrying out dead-time advance compensation on a corresponding dead time according to a dead-time length of the switch in the rectifier and the desired action time to obtain an instruction action time; controlling the corresponding switch in the rectifier according to all the instruction action times.

5. The rectifier control method of claim 1, wherein Before controlling the rectifier according to the current modulation wave voltage, the method further comprises: setting a carrier phase shift angle of the rectifier to (π / N)+α, wherein N is a positive integer representing the number of all the rectifiers, and α is a preset deviation angle.

6. The rectifier control method of claim 1, wherein The method further comprises: filtering the grid-side current through a filter winding; the filter winding is a transformer winding on the same side of the rectifier.

7. The rectifier control method of claim 1, wherein The process of phase angle correcting the actual harmonic current according to the preset phase angle offset to obtain the corrected harmonic current corresponding to the phase angle of the current modulation wave voltage of the rectifier comprises: offsetting an actual phase angle of the actual harmonic current by the preset phase angle offset to obtain the corrected harmonic current corresponding to the phase angle of the current modulation wave voltage of the rectifier.

8. The rectifier control method according to any one of claims 1 to 7, characterized by, Before adjusting the current modulation wave voltage according to the corrected harmonic current and controlling the rectifier according to the current modulation wave voltage to eliminate the actual harmonic current in the grid-side current, the method further comprises: determining the current modulation wave voltage through a double closed-loop control strategy according to actual current, actual intermediate voltage and reference intermediate voltage of the rectifier.

9. The rectifier control method of claim 8, wherein When the current loop control in the double closed-loop control strategy is PI control, a proportional coefficient of the PI control is a minimum value for reaching a preset response condition.

10. The rectifier control method of claim 8, wherein When the current loop control in the double closed-loop control strategy is PR control, in control parameters of the PR control, a proportional coefficient is a minimum value for reaching a preset response condition, and / or, a resonance coefficient is a maximum value for reaching the preset response condition, and / or, a cutoff frequency is a minimum value for reaching the preset response condition.

11. A rectifier control system characterized by, The method comprises: an acquisition module configured to acquire an actual harmonic current of a preset frequency in a grid-side current of a rectifier; a correction module configured to perform phase angle correction on the actual harmonic current according to a preset phase angle offset to obtain a corrected harmonic current corresponding to a phase angle of a current modulation wave voltage of the rectifier; an adjustment module configured to subtract a reference harmonic current set value from the corrected harmonic current to obtain a harmonic voltage, and / or multiply the corrected harmonic current by a preset proportional coefficient to obtain a harmonic voltage; update the current modulation wave voltage to a superposition value of an opposite value of the harmonic voltage and the current modulation wave voltage to eliminate the actual harmonic current in the grid-side current; the preset phase angle offset comprises a first phase angle offset between the modulation wave voltage and the actual harmonic current, and / or a second phase angle offset generated by a notch filter when the actual harmonic current is acquired.

12. An electronic device, comprising: The method comprises: a memory configured to store a computer program; a processor configured to execute the computer program to implement the steps of the rectifier control method according to any one of claims 1 to 10.

13. A readable storage medium, characterized by, The computer program is stored on the readable storage medium and is executed by the processor to implement the steps of the rectifier control method according to any one of claims 1 to 10.

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