High-frequency damping control method, rectifier based on LCL filtering and storage medium

Abstract

The invention provides a high-frequency damping control method, an LCL filtering-based rectifier and a storage medium, and the method comprises the steps: obtaining a capacitor voltage detection value of a filter capacitor, a bridge arm current detection value of a rectifier bridge and a real-time phase locking angle of an input voltage, and generating a capacitor voltage reference value according to the capacitor voltage detection value and the real-time phase locking angle; virtual impedance is generated according to the capacitor voltage detection value and the capacitor voltage reference value, PI control is carried out on the virtual impedance through a first PI controller, and a virtual current value is generated; and PI control is carried out on a result obtained by superposing the virtual current value and the current reference value and a bridge arm current detection value through a second PI controller, a control voltage is generated, and on-off control is carried out on each bridge arm in the rectifier bridge based on the control voltage and a real-time phase locking angle. According to the invention, the stability of the rectifier based on LCL filtering can be improved.

Description

Technical Field

[0001] The present invention relates to the field of DC power supplies, and more particularly, to a high-frequency damping control method, a rectifier based on LCL filtering, and a computer-readable storage medium. Background Art

[0002] A rectifier based on LCL filtering is a commonly used DC power supply topology, which can provide a stable DC output and has a low input current harmonic content and a high input power factor. As Figure 1 shown, the above rectifier includes a rectifier bridge 11 and an LCL filtering component 12, and its control method is usually a double-loop structure, that is, a bus voltage outer loop and a bridge arm current inner loop. This control system only needs to detect the input voltage, the bridge arm current, and the DC bus voltage to support, and the control logic is relatively simple, but the stability of the system is slightly poor. For example, when there are high-frequency ripples on the input AC source or the inductive reactance characteristics of the input cable change, it may cause the entire rectifier to operate unstably, the bus voltage to fluctuate more, and the input current and the filter capacitor voltage to have high-frequency oscillations.

[0003] As Figure 2 shown, when an inductor is connected in series at the front end of the LCL filtering component 12, when the rectifier is connected to the input voltage 21, high-frequency ripples will appear in the filter capacitor voltage 23, the front-end current, and the back-end current 22 in the LCL filtering component 12, and the bus voltage 24 will also fluctuate. These high-frequency ripples will cause the temperature of the rectifier bridge 11 and the LCL filtering component 12 to rise, the current stress to increase, the noise to increase, and even cause overcurrent shutdown. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-frequency damping control method, a rectifier based on LCL filtering, and a computer-readable storage medium for the problem of slightly poor system stability of the above rectifier based on LCL filtering.

[0005] The technical solution of the present invention to solve the above technical problem is to provide a high-frequency damping control method, which is applied to a rectifier based on LCL filtering. The rectifier includes a rectifier bridge, and the AC input end of the rectifier bridge is connected to an AC power supply via an LCL filtering component, and the LCL filtering component includes a filter capacitor. The high-frequency damping control method includes:

[0006] Obtain the capacitance voltage detection value of the filter capacitor, the bridge arm current detection value of the rectifier bridge, and the real-time phase-locked angle of the input voltage, and generate a capacitance voltage reference value according to the capacitance voltage detection value and the real-time phase-locked angle;

[0007] Generate a virtual impedance according to the capacitance voltage detection value and the capacitance voltage reference value, and perform PI control on the virtual impedance through a first PI controller to generate a virtual current value;

[0008] The result of superimposing the virtual current value and the current reference value through a second PI controller and the arm current detection value are subjected to PI control to generate a control voltage, and on-off control is performed on each arm in the rectifier bridge based on the control voltage and the real-time phase-locked angle.

[0009] As a further improvement of the present invention, the rectifier based on LCL filtering is a three-phase rectifier; the generating of the capacitor voltage reference value according to the capacitor voltage detection value and the real-time phase-locked angle includes:

[0010] Performing a Clarke transform on the capacitor voltage detection values corresponding to three filter capacitors at the same moment to form a voltage vector in a two-phase stationary coordinate system, and performing a Park transform on the voltage vector in the two-phase stationary coordinate system using the real-time phase-locked angle to form a d-axis feedback voltage and a q-axis feedback voltage;

[0011] Filter the d-axis feedback voltage and the q-axis feedback voltage respectively to obtain a d-axis capacitor voltage reference value and a q-axis capacitor voltage reference value.

[0012] As a further improvement of the present invention, the generating of the virtual impedance according to the capacitor voltage detection value and the capacitor voltage reference value includes:

[0013] Subtract the d-axis feedback voltage and the d-axis capacitor voltage reference value to extract the high-frequency component on the d-axis feedback voltage, and multiply the high-frequency component on the d-axis feedback voltage by a preset value to obtain a d-axis virtual impedance;

[0014] Subtract the q-axis feedback voltage and the q-axis capacitor voltage reference value to extract the high-frequency component on the q-axis feedback voltage, and multiply the high-frequency component on the q-axis feedback voltage by a preset value to obtain a q-axis virtual impedance.

[0015] As a further improvement of the present invention, the transfer function of the first PI controller is:

[0016] IvirtualMd = Kp1 * RvirtualMd + ∫Ki1 * RvirtualMd,

[0017] IvirtualMq = Kp2 * RvirtualMq + ∫Ki2 * RvirtualMq,

[0018] where IvirtualMd is the d-axis virtual current value, RvirtualMd is the d-axis virtual impedance, IvirtualMq is the q-axis virtual current value, RvirtualMq is the q-axis virtual impedance, Kp1 and Kp2 are proportionality coefficients, and Ki1 and Ki2 are integral coefficients.

[0019] As a further improvement of the present invention, the transfer function of the second PI controller is:

[0020] Vregd = Vd - Kp3 * (IrefInd - Id) - ∫Ki3 * (IrefInd - Id),

[0021] Vregq = Vq - Kp4 * (IrefInq - Iq) - ∫Ki4 * (IrefInq - Iq),

[0022] where Vregd is the d-axis control voltage, Vd is the d-axis feedback voltage, IrefInd is the result of superimposing the d-axis virtual current value and the d-axis current reference value, Id is the d-axis feedback current, Vregq is the q-axis control voltage, Vq is the q-axis feedback voltage, IrefInq is the result of superimposing the q-axis virtual current value and the q-axis current reference value, Iq is the q-axis feedback current, Kp3 and Kp4 are proportionality coefficients, and Ki3 and Ki4 are integral coefficients.

[0023] As a further improvement of the present invention, the rectifier based on LCL filtering is a single-phase rectifier, and generating the capacitor voltage reference value according to the capacitor voltage detection value and the real-time phase-locked angle includes: first calculating the capacitor voltage modulus value through the capacitor voltage detection value, and then multiplying the capacitor voltage modulus value by the sine value of the real-time phase-locked angle to generate the capacitor voltage reference value.

[0024] As a further improvement of the present invention, generating the virtual impedance according to the capacitor voltage detection value and the capacitor voltage reference value includes: taking the difference between the capacitor voltage detection value and the capacitor voltage reference value to extract the high-frequency component on the feedback voltage, and multiplying the high-frequency component on the feedback voltage by a preset value to obtain the virtual impedance.

[0025] As a further improvement of the present invention, the transfer function of the first PI controller is:

[0026] Ivirtual = Kp1 * Rvirtual + ∫Ki1 * Rvirtual,

[0027] where Ivirtual is the virtual current value, Rvirtual is the virtual impedance, Kp1 is the proportionality coefficient, and Ki1 is the integral coefficient;

[0028] The transfer function of the second PI controller is:

[0029] Vreg = Vcap - Kp2 * (IrefIn - I1) - ∫Ki2 * (IrefIn - I1),

[0030] Wherein, Vreg is the control voltage, Vcap is the detected value of the capacitor voltage, Iref is the result of superimposing the virtual current value and the current reference value, I1 is the feedback current, Kp2 is the proportional coefficient, and Ki2 is the integral coefficient.

[0031] The present invention also provides a rectifier based on LCL filtering. The rectifier includes a rectifier bridge, an LCL filtering component, a memory, a processor, and a computer program stored in the memory and executable on the processor. The AC input terminal of the rectifier bridge is connected to an AC power supply via the LCL filtering component, and the LCL filtering component includes a filtering capacitor. When the processor executes the computer program, the steps of the high-frequency damping control method described above are implemented.

[0032] The present invention also provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the steps of the high-frequency damping control method described above are implemented.

[0033] The present invention has the following beneficial effects: A virtual impedance is generated according to the voltage of the filtering capacitor obtained by real-time detection, and the inner current loop reference of the rectifier bridge arm is optimized through virtual impedance control, thereby weakening the influence of high-frequency fluctuations on the AC input line on the rectifier and improving the stability of the rectifier based on LCL filtering. Description of the Drawings

[0034] Figure 1 is a schematic circuit topology diagram of a rectifier based on LCL filtering.

[0035] Figure 2 is a waveform diagram of the rectifier bridge voltage and current after an inductor is connected in series at the front end of the LCL filtering component of the rectifier based on LCL filtering.

[0036] Figure 3 is a schematic flowchart of the high-frequency damping control method provided by an embodiment of the present invention.

[0037] Figure 4 is a control diagram of the high-frequency damping control method provided by an embodiment of the present invention applied to a three-phase rectifier.

[0038] Figure 5 is a waveform diagram of the rectifier bridge voltage and current after an inductor is connected in series at the front end of the LCL filtering component of the rectifier based on LCL filtering after using the high-frequency damping control method provided by an embodiment of the present invention.

[0039] Figure 6 is a control diagram of the high-frequency damping control method provided by an embodiment of the present invention applied to a single-phase rectifier. Detailed Embodiments

[0040] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] As Figure 3 shown, it is a schematic flowchart of a high-frequency damping control method provided by an embodiment of the present invention. This high-frequency damping control method can be applied to a rectifier based on LCL filtering as Figure 1 shown. The rectifier includes a rectifier bridge 11, an LCL filtering component 12 and a control unit. The AC input terminals of the rectifier bridge 11, which include a plurality of controllable semiconductor switches (such as IGBTs, MOSFETs, turn-off thyristors, thyristors, etc.), are connected to an AC power supply via the LCL filtering component 12, and the LCL filtering component includes a filtering capacitor. The control unit is respectively connected to the rectifier bridge 11 and the LCL filtering component 12, obtains corresponding parameters from the LCL filtering component 12, and sends on-off control signals to the controllable semiconductor switches of the rectifier bridge 11. Specifically, the control unit can be composed of a main controller and a peripheral circuit, and the main controller is respectively connected to the rectifier bridge 11 and the LCL filtering component 12 through the peripheral circuit.

[0042] The high-frequency damping control method of this embodiment can be integrated into the control unit. This method includes the following steps:

[0043] Step S31: Obtain the capacitance voltage detection value of the filtering capacitor, the arm current detection value of the rectifier bridge, and the real-time phase-locked angle of the input voltage, and generate a capacitance voltage reference value according to the capacitance voltage detection value and the real-time phase-locked angle.

[0044] Specifically, the control unit may include a voltage detection circuit, and the input terminal of this voltage detection circuit is connected to both ends of the filtering capacitor in the LCL filtering component 12. When the LCL filtering component 12 includes a plurality of filtering capacitors, the control unit may include a plurality of voltage and current detection circuits, and respectively perform real-time detection of the voltages of the plurality of filtering capacitors through the plurality of voltage detection circuits, and respectively perform real-time detection of the currents of the plurality of arms of the rectifier bridge through the plurality of current detection circuits. The control unit further includes a voltage sampling circuit. This voltage sampling circuit can sample the input voltage of the rectifier based on LCL filtering, and the control unit calculates the real-time phase-locked angle according to the voltage sampling value. The above voltage detection circuit, voltage sampling circuit, and the specific method of calculating the real-time phase-locked angle according to the voltage sampling value can all adopt the conventional techniques in the art and will not be elaborated here.

[0045] Step S32: Generate a virtual impedance according to the capacitance voltage detection value and the capacitance voltage reference value, and perform PI control on the virtual impedance through a first PI controller to generate a virtual current value.

[0046] The above-mentioned first PI controller can be implemented by software running on the control unit, that is, it consists of an analog PI control algorithm running on the control unit, and the input signal of the first PI controller is a virtual impedance generated according to the detected value of the capacitor voltage and the reference value of the capacitor voltage.

[0047] Step S33: Perform PI control on the result of superimposing the virtual current value and the current reference value through the second PI controller to generate a control voltage, and perform on-off control on each arm of the rectifier bridge based on the control voltage and the real-time phase-locked angle. The current reference value can be generated by a voltage outer-loop PI controller, and the inputs of the voltage outer-loop PI controller are the voltage reference value (specified in the control signal) and the DC bus sampling value (i.e., the voltage difference between the two DC buses at the output end of the rectifier bridge).

[0048] Similarly, the second PI controller can be implemented by software running on the control unit, that is, the second PI controller consists of an analog PI control algorithm running on the control unit, and the input signal of the second PI controller is the result of superimposing the virtual current value and the current reference value, the detected value of the capacitor voltage obtained in step S31, and the current sampling value (i.e., the arm current flowing through the rectifier bridge).

[0049] Specifically, performing on-off control on each arm of the rectifier bridge based on the control voltage and the real-time phase-locked angle may include: performing Park inverse transformation and Clarke inverse transformation on the control voltage, and then generating a PWM wave for controlling the on-off of the controllable semiconductor switch of the arm of the rectifier bridge according to the transformation result.

[0050] The above-mentioned high-frequency damping control method generates a virtual impedance according to the voltage of the filter capacitor obtained by real-time detection, and optimizes the current inner-loop setting of the rectifier bridge arm through virtual impedance control, so as to weaken the influence of high-frequency fluctuations on the AC input line on the rectifier, and further improve the stability of the rectifier based on LCL filtering.

[0051] As Figure 4 shown, when the rectifier based on LCL filtering is a three-phase rectifier, that is, the rectifier bridge 11 includes three-phase arms, the AC power supply connected to the rectifier includes three input phase lines, and the LCL filtering component 12 includes three filter capacitors respectively connected in series between the three input phase lines, as Figure 1 shown.

[0052] Accordingly, generating the capacitor voltage reference value based on the capacitor voltage detection value and the real-time phase-locked angle in step S31 specifically includes: performing a Clarke transformation on the capacitor voltage detection values corresponding to the three filter capacitor voltages at the same moment to form a voltage vector in the two-phase stationary coordinate system, and using the real-time phase-locked angle to perform a Park transformation on the voltage vector in the two-phase stationary coordinate system to form a d-axis feedback voltage and a q-axis feedback voltage; then respectively filtering the d-axis feedback voltage and the q-axis feedback voltage to obtain a d-axis capacitor voltage reference value and a q-axis capacitor voltage reference value.

[0053] In this step S31, the d-axis feedback voltage Vd and the q-axis feedback voltage Vq can be filtered respectively according to a filtering function (such as an average filtering function, etc.) in the timing interrupt execution program to obtain a d-axis capacitor voltage reference value VdRef and a q-axis capacitor voltage reference value VqRef.

[0054] In step S32, generating a virtual impedance based on the capacitor voltage detection value and the capacitor voltage reference value specifically includes: taking the difference between the d-axis feedback voltage Vd and the d-axis capacitor voltage reference value VdRef, extracting the high-frequency component ΔVd on the d-axis feedback voltage, and ΔVd = Vd - VdRef, and multiplying the high-frequency component ΔVd on the d-axis feedback voltage by a preset value K to obtain a d-axis virtual impedance RvirtualMd, and RvirtualMd = ΔVd * K; and taking the difference between the q-axis feedback voltage Vq and the q-axis capacitor voltage reference value VqRef, extracting the high-frequency component ΔVq on the q-axis feedback voltage, ΔVq = Vq - VqRef, and multiplying the high-frequency component ΔVq on the q-axis feedback voltage by a preset value K to obtain a q-axis virtual impedance RvirtualMq = ΔVq * K.

[0055] In an embodiment of the present invention, the first PI controller can perform PI control on the virtual impedance by using the following transfer function:

[0056] IvirtualMd = Kp1 * RvirtualMd + ∫Ki1 * RvirtualMd (1)

[0057] IvirtualMq = Kp2 * RvirtualMq + ∫Ki2 * RvirtualMq (2)

[0058] Where IvirtualMd is the d-axis virtual current value, IvirtualMq is the q-axis virtual current value, Kp1 and Kp2 are proportionality coefficients, and Ki1 and Ki2 are integral coefficients.

[0059] In an embodiment of the present invention, in step S33, the transfer function of the second PI controller is:

[0060] Vregd = Vd - Kp3 * (IrefInd - Id) - ∫Ki3 * (IrefInd - Id) (3)

[0061] Vregq = Vq - Kp4 * (IrefInq - Iq) - ∫Ki4 * (IrefInq - Iq) (4)

[0062] Where Vregd is the d-axis control voltage, IrefInd is the result of superimposing the d-axis virtual current value IvirtualMd and the d-axis current reference value IrefMd (i.e., IrefInd = IvirtualMd + IrefMd), Id is the d-axis feedback current, Vregq is the q-axis control voltage, IrefInq is the result of superimposing the q-axis virtual current value IvirtualMq and the q-axis current reference value IrefMq (i.e., IrefInq = IvirtualMq + IrefMq), Iq is the q-axis feedback current, Kp3 and Kp4 are proportionality coefficients, and Ki3 and Ki4 are integral coefficients. Specifically, the input current of the rectifier bridge can be sampled, and the three-phase bridge arm currents obtained by sampling are subjected to Clarke transformation and Park transformation to obtain the d-axis feedback current Id and the q-axis feedback current Iq. The d-axis current reference value IrefMd comes from the output of the voltage outer loop PI regulator. The q-axis current reference value IrefMq is related to the capacitance value of the LCL filter capacitor and can also be designed to be zero.

[0063] As Figure 5 shown, under the same conditions, that is, an inductor is connected in series at the front end of the LCL filter component 12 and the above high-frequency damping control method is used to control the on-off of the controllable semiconductor switches of each bridge arm in the rectifier bridge. After the rectifier is connected to the input voltage 51, the high-frequency ripples of the filter capacitor voltage 53, the front-end current, and the back-end current 52 in the LCL filter component 12 are basically eliminated, and the bus voltage 54 is also more stable than before, greatly improving the stability of the operation of the rectifier based on LCL filtering.

[0064] As Figure 6 shown, when the rectifier based on LCL filtering is a single-phase rectifier, generating the capacitor voltage reference value according to the capacitor voltage detection value and the real-time phase-locked angle in the above step S31 includes: generating the input voltage modulus Vm according to the capacitor voltage detection value Vcap, and multiplying the input voltage modulus Vm and the sine value sinθ of the real-time phase-locked angle to generate the capacitor voltage reference value VcapRef, and VcapRef = Vm * sinθ.

[0065] Accordingly, generating the virtual impedance based on the capacitance voltage detection value and the capacitance voltage reference value in step S32 includes: taking the difference between the capacitance voltage detection value Vcap and the capacitance voltage reference value VcapRef to extract the high-frequency component ΔVcap on the feedback voltage, and ΔVcap = Vcap - VcapRef, and multiplying the high-frequency component ΔVcap on the feedback voltage by a preset value K to obtain the virtual impedance Rvirtual, and Rvirtual = ΔVcap * K.

[0066] In an embodiment of the present invention, the transfer function of the first PI controller is:

[0067] Ivirtual = Kp1 * Rvirtual + ∫Ki1 * Rvirtual (5)

[0068] Wherein, Ivirtual is the virtual current value, Kp1 is the proportional coefficient, and Ki1 is the integral coefficient.

[0069] The transfer function of the second PI controller is:

[0070] Vreg = Vcap - Kp2 * (IrefIn - I1) - ∫Ki2 * (IrefIn - I1) (6)

[0071] Where Vreg is the control voltage, Vcap is the capacitance voltage detection value, Iref is the result of superimposing the virtual current value and the current reference value, I1 is the feedback current, Kp2 is the proportional coefficient, and Ki2 is the integral coefficient.

[0072] The present invention also provides a rectifier based on LCL filtering. The rectifier includes a rectifier bridge, an LCL filtering component, a memory, a processor, and a computer program stored in the memory and executable on the processor. The AC input end of the rectifier bridge is connected to an AC power supply via the LCL filtering component, and the LCL filtering component includes a filtering capacitor. When the processor executes the computer program, the steps of the high-frequency damping control method described above are implemented.

[0073] The rectifier based on LCL filtering in this embodiment and the above Figures 3 - 6 The high-frequency damping control method in the corresponding embodiment belong to the same concept. The specific implementation process is detailed in the corresponding method embodiment, and the technical features in the method embodiment are all correspondingly applicable in this device embodiment and will not be elaborated here.

[0074] The present invention also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the high-frequency damping control method described above are implemented.

[0075] The computer-readable storage medium in this embodiment and the high-frequency damping control method in the corresponding above Figures 3 - 6 corresponding embodiment belong to the same concept. For the specific implementation process, please refer to the corresponding method embodiment in detail. Moreover, the technical features in the method embodiment are all correspondingly applicable in this device embodiment and will not be elaborated here.

[0076] It should be understood that the sequence numbers of the steps in the above embodiments do not indicate the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this application.

[0077] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0078] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in this article can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0079] In the embodiments provided in this application, it should be understood that the disclosed high-frequency damping control method and the rectifier based on LCL filtering can be implemented in other ways.

[0080] To implement all or part of the processes in the above method embodiments of this application, it can also be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or interface switching device, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc., that can carry the computer program code.

[0081] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A high-frequency damping control method is applied to a rectifier based on LCL filtering. The rectifier includes a rectifier bridge, and the AC input terminal of the rectifier bridge is connected to an AC power source via an LCL filtering component. The LCL filtering component includes a filtering capacitor, and it is characterized in that, The high-frequency damping control method comprises: Acquire a capacitor voltage detection value of the filter capacitor, a bridge arm current detection value of the rectifier bridge, and a real-time phase-locked angle of the input voltage, and generate a capacitor voltage reference value according to the capacitor voltage detection value and the real-time phase-locked angle; generating a virtual impedance according to the capacitor voltage detection value and the capacitor voltage reference value, and performing PI control on the virtual impedance through a first PI controller to generate a virtual current value; The result of superimposing the virtual current value and the current reference value and the bridge arm current detection value are PI controlled by the second PI controller to generate a control voltage, and the on-off control of each bridge arm in the rectifier bridge is performed based on the control voltage and the real-time phase-locked angle.

2. The high-frequency damping control method according to claim 1, wherein The LCL filter-based rectifier is a three-phase rectifier; the capacitor voltage reference value is generated according to the capacitor voltage detection value and the real-time phase-locked angle, including: Performing Clarke transformation on the capacitor voltage detection values corresponding to the three filter capacitors at the same time to form a voltage vector in a two-phase stationary coordinate system, and performing Park transformation on the voltage vector in the two-phase stationary coordinate system using the real-time phase-locked angle to form a d-axis feedback voltage and a q-axis feedback voltage; The d-axis feedback voltage and the q-axis feedback voltage are filtered respectively to obtain a d-axis capacitor voltage reference value and a q-axis capacitor voltage reference value.

3. The high-frequency damping control method according to claim 2, characterized in that: Generating a virtual impedance according to the capacitor voltage detection value and the capacitor voltage reference value includes: The d-axis feedback voltage and the d-axis capacitor voltage reference value are subtracted to obtain the high-frequency component of the d-axis feedback voltage, and the high-frequency component of the d-axis feedback voltage is multiplied by a preset value to obtain the d-axis virtual impedance; The q-axis feedback voltage and the q-axis capacitor voltage reference value are subtracted to obtain the high-frequency component of the q-axis feedback voltage, and the high-frequency component of the q-axis feedback voltage is multiplied by a preset value to obtain the q-axis virtual impedance.

4. The high-frequency damping control method according to claim 2, wherein The transfer function of the first PI controller is: IvirtualMd=Kp1*RvirtualMd+∫Ki1*RvirtualMd, IvirtualMq=Kp2*RvirtualMq+∫Ki2*RvirtualMq, Where IvirtualMd is the d-axis virtual current value, RvirtualMd is the d-axis virtual impedance, IvirtualMq is the q-axis virtual current value, RvirtualMq is the q-axis virtual impedance, Kp1 and Kp2 are proportional coefficients, and Ki1 and Ki2 are integral coefficients.

5. The high-frequency damping control method according to claim 2, wherein The transfer function of the second PI controller is: Vregd=Vd-Kp3*(IrefInd-Id)-∫Ki3*(IrefInd-Id), Vregq=Vq-Kp4*(IrefInq-Iq)-∫Ki4*(IrefInq-Iq), Wherein, Vregd is the d-axis control voltage, Vd is the d-axis feedback voltage, IrefInd is the result of superimposing the d-axis virtual current value and the d-axis current reference value, Id is the d-axis feedback current, Vregq is the q-axis control voltage, Vq is the q-axis feedback voltage, IrefInq is the result of superimposing the q-axis virtual current value and the q-axis current reference value, Iq is the q-axis feedback current, Kp3 and Kp4 are proportional coefficients, and Ki3 and Ki4 are integral coefficients.

6. The high-frequency damping control method according to claim 1, characterized in that The LCL filtering-based rectifier is a single-phase rectifier, and the capacitor voltage reference value is generated according to the capacitor voltage detection value and the real-time phase-locked angle, including: first calculating the capacitor voltage modulus through the capacitor voltage detection value, and then multiplying the capacitor voltage modulus and the sine value of the real-time phase-locked angle to generate the capacitor voltage reference value.

7. The high-frequency damping control method according to claim 6, wherein Generating the virtual impedance according to the capacitor voltage detection value and the capacitor voltage reference value includes: taking the difference between the capacitor voltage detection value and the capacitor voltage reference value to extract the high-frequency component of the feedback voltage, and multiplying the high-frequency component of the feedback voltage by a preset value to obtain the virtual impedance.

8. The high-frequency damping control method according to claim 6, characterized in that: The transfer function of the first PI controller is: Ivirtual=Kp1*Rvirtual+∫Ki1*Rvirtual, Where Ivirtual is the virtual current value, Rvirtual is the virtual impedance, Kp1 is the proportional coefficient, and Ki1 is the integral coefficient; The transfer function of the second PI controller is: Vreg=Vcap-Kp2*(IrefIn-I1)-∫Ki2*(IrefIn-I1), Where Vreg is the control voltage, Vcap is the capacitor voltage detection value, Iref is the result of superimposing the virtual current value and the current reference value, I1 is the feedback current, Kp2 is the proportional coefficient, and Ki2 is the integral coefficient.

9. A rectifier based on LCL filtering, the rectifier comprising a rectifier bridge, an LCL filtering component, a memory, a processor, and a computer program stored in the memory and executable on the processor, an AC input end of the rectifier bridge being connected to an AC power supply via the LCL filtering component, and the LCL filtering component including a filtering capacitor, characterized in that, When the processor executes the computer program, the steps of the high-frequency damping control method according to any one of claims 1 to 8 are implemented.

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

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