Control method of power converter and power conversion device

Abstract

The invention relates to a control method of a power converter, the power converter comprises a filtering module, an inductor and a switching circuit, the control method comprises the following steps: providing a voltage loop unit, detecting the output voltage of the power converter, and outputting a voltage compensation signal according to the output voltage and a voltage reference signal; providing a multi-order high-frequency filter, receiving the voltage signal of the filtering module, and outputting a filtering signal; providing a current compensation module, receiving the voltage signal of the filtering module, the inductive current flowing through the inductor and a voltage compensation signal, and correspondingly outputting a current compensation signal; superposing the filtering signal and the current compensation signal to obtain a first control signal; and providing a driving module for receiving the first control signal and correspondingly outputting a second control signal to control a switch assembly in the switch circuit. The invention also relates to a power conversion device.

Description

Technical Field

[0001] This case belongs to the field of a power converter, especially a control method for a power converter and a power conversion device. Background Art

[0002] A weak power grid is a part or a specific area in the power system with poor voltage stability and large voltage fluctuations. In these areas, due to reasons such as load changes, imperfect power grid topology, or insufficient power supply, the voltage stability is poor, and voltage fluctuations or voltage deviation from the normal operating range are likely to occur. In these areas, various measures are usually required to improve the power grid stability to ensure the normal operation of the power converter and the safety of user equipment.

[0003] Currently, the first type of solution for a weak power grid adopted by a power conversion device is the identification method, that is, by collecting the current in the power conversion device and performing filtering or feature quantity (such as the amplitude of the current in a certain frequency band) extraction processing to judge in real time whether it is in the weak power grid condition. If it is in the weak power grid condition, the extracted feature quantity is analyzed, and the pre-set parameters are selected correspondingly according to the analysis results. However, the identification method not only requires a certain time delay to ensure the accuracy of the judgment, but may also misjudge the weak power grid due to the waveform distortion of the grid voltage.

[0004] The second type of solution for a weak power grid adopted by a power conversion device is the grid voltage feed-forward control method. By processing the grid voltage feed-forward, it can be compatible with both weak power grid and normal power grid conditions, eliminating the identification and switching operations in the identification method, and at the same time suppressing the background harmonics of the grid voltage to enhance the dynamic response ability of the power grid. However, the currently adopted grid voltage feed-forward control method sacrifices the harmonic suppression ability under normal power grid conditions in order to be compatible with the stable operation under weak power grid, that is, the currently adopted grid voltage feed-forward control method for the power converter cannot be compatible with normal power grid and weak power grid.

[0005] Therefore, it is necessary to develop a control method for a power converter and a power conversion device to solve the problems and deficiencies faced by the existing technology. Summary of the Invention

[0006] The purpose of this case is to provide a control method for a power converter and a power conversion device, which can be compatible with normal power grid and weak power grid, retain the background harmonics of the grid voltage in the low frequency band, filter out high-order harmonics in the high frequency band, and do not need to identify whether it is in the weak power grid mode currently, nor do any parameter switching, avoiding problems such as incorrect mode identification and uneven switching parameters.

[0007] To achieve the above object, a preferred embodiment of this case is a control method for a power converter, characterized in that the power converter is electrically connected to the power grid, and the power converter includes a filtering module, a first inductor, and a switching circuit, wherein the filtering module is in parallel with the power grid, and the switching circuit and the first inductor are connected in series and then in parallel with the filtering module. The control method includes: providing a voltage loop unit, which is electrically connected to the output end of the power converter, for detecting the output voltage of the power converter and outputting a voltage compensation signal according to the output voltage and a first voltage reference signal; providing a multi-stage high-frequency filter, which is electrically connected to the filtering module, for receiving the voltage signal of the filtering module and performing filtering to output a filtered signal; providing a current compensation module, which is electrically connected to the filtering module, the first inductor, and the voltage loop unit, for receiving the voltage signal of the filtering module, the inductor current flowing through the first inductor, and the voltage compensation signal, and correspondingly outputting a current compensation signal; superimposing the filtered signal and the current compensation signal to obtain a first control signal; and providing a driving module, which is electrically connected to the multi-stage high-frequency filter, the current compensation module, and the switching circuit, for receiving the first control signal and correspondingly outputting a second control signal, and the second control signal is used to control the duty cycle of the switching component in the switching circuit.

[0008] To achieve the above object, another preferred embodiment of this case is a power conversion device, characterized in that it includes: a power converter, including: a filtering module, in parallel with the power grid; a first inductor; and a switching circuit, connected in series with the first inductor and then in parallel with the filtering module; and a control unit, including: a voltage loop unit, electrically connected to the output end of the power converter, for detecting the output voltage of the power converter and outputting a voltage compensation signal according to the output voltage and a first voltage reference signal; a multi-stage high-frequency filter, electrically connected to the filtering module, for receiving the voltage signal of the filtering module and performing filtering to output a filtered signal; a current compensation module, electrically connected to the filtering module, the first inductor, and the voltage loop unit, for receiving the voltage signal of the filtering module, the inductor current flowing through the first inductor, and the voltage compensation signal, and correspondingly outputting a current compensation signal; a driving module, electrically connected to the multi-stage high-frequency filter, the current compensation module, and the switching circuit, for receiving a first control signal formed by superimposing the filtered signal and the current compensation signal and correspondingly outputting a second control signal, and the second control signal is used to control the duty cycle of the switching component in the switching circuit. Description of the Drawings

[0009] Figure 1 It is a schematic diagram of the step flow of the control method of the preferred embodiment of this case.

[0010] Figure 2 For Figure 1 the circuit architecture schematic of the power conversion device applicable to the control method shown.

[0011] Figure 3 ForFigure 2 Schematic diagram of the detailed circuit of the power conversion device shown

[0012] Figure 4A For a traditional power conversion device using the grid voltage feedforward control method and a single-phase phase-locked loop as the feedforward, it is the current simulation diagram at the input end of the power conversion device

[0013] Figure 4B For a traditional power conversion device using the grid voltage feedforward control method and a first-order low-pass filter as the feedforward, it is the current simulation diagram at the input end of the power conversion device

[0014] Figure 4C For the power conversion device in this case using the grid voltage feedforward control method and a multi-order high-frequency filter as the feedforward, it is the current simulation diagram at the input end of the power conversion device

[0015] Figure 5A For a traditional power conversion device using the grid voltage feedforward control method and a single-phase phase-locked loop as the feedforward, it is the current harmonic spectrum analysis diagram

[0016] Figure 5B For a traditional power conversion device using the grid voltage feedforward control method and a first-order low-pass filter as the feedforward, it is the current harmonic spectrum analysis diagram

[0017] Figure 5C For the power conversion device in this case using the grid voltage feedforward control method and a multi-order high-frequency filtering device as the feedforward, it is the current harmonic spectrum analysis diagram

[0018] Among them, the reference numerals are explained as follows:

[0019] 1: Power conversion device

[0020] 1a: Power converter

[0021] Grid: Power grid

[0022] Ug: Input voltage

[0023] 8: Load

[0024] Vo: Output voltage

[0025] 2: Filter module

[0026] L1: First inductor

[0027] 3: Switching circuit

[0028] 4: Control unit

[0029] C1: Filter capacitor

[0030] Uc: Capacitor voltage

[0031] iL1: Inductive current

[0032] 40: Voltage loop unit

[0033] 41: Multistage high-frequency filter

[0034] 42: Current compensation module

[0035] 43: Drive module

[0036] Vref: First voltage reference signal

[0037] Vloop: Voltage compensation signal

[0038] UHS: Filtered signal

[0039] iloop: Current compensation signal

[0040] Vs1: First control signal

[0041] Vs2: Second control signal

[0042] S1~S5: Steps of the control method

[0043] 400: First PI regulator

[0044] 420: Phase-locked loop unit

[0045] θ: Phase angle signal

[0046] cosθ: Cosine signal

[0047] 421: First integrator

[0048] 422: Coordinate transformation unit

[0049] 423: Second PI regulator

[0050] 424: Second integrator

[0051] 425: Calculation unit

[0052] V`, qV`: Quadrature signals

[0053] Vd: d-axis voltage signal

[0054] Vq: q-axis voltage signal

[0055] Vqref: Second voltage reference signal

[0056] △W: Frequency offset

[0057] Wn: Nominal frequency

[0058] 426: Current loop unit

[0059] 427: Multiplier

[0060] 428: Third PI regulator

[0061] iLref: Current reference signal

[0062] 430: Modulation circuit

[0063] 431: Drive circuit

[0064] Vp: Modulation signal

[0065] 5: PFC circuit

[0066] Cbus: Bus capacitor

[0067] L2: Second inductor Detailed implementation manners

[0068] Some typical embodiments embodying the features and advantages of this case will be described in detail in the following description. It should be understood that this case can have various changes in different aspects, all of which do not depart from the scope of this case, and the descriptions and drawings therein are essentially for illustrative purposes and not for limiting this case.

[0069] Please refer to Figure 1 、 Figure 2 and Figure 3 wherein Figure 1 is a schematic diagram of the step flow of the control method of the preferred embodiment of this case, Figure 2 is Figure 1 a schematic diagram of the circuit block of the power conversion device applicable to the control method shown, Figure 3 is Figure 2 a detailed circuit diagram of the power conversion device shown. The control method of this case is applicable to Figure 2In the power converter 1a of the power conversion device 1 shown, the input end of the power conversion device 1 is electrically connected to the power grid Grid to receive the input voltage Ug provided by the power grid Grid. The output end of the power converter 1a is electrically connected to the load 8. The power converter 1a is used to convert the input voltage Ug and output the voltage Vo at the output end. The power conversion device 1 includes a power converter 1a and a control unit 4. The power converter 1a operates under the control of the control unit 4, and the power converter 1a includes a filtering module 2, a first inductor L1, and a switching circuit 3. The filtering module 2 is electrically connected to the input end of the power converter 1a and is electrically connected in parallel with the power grid Grid via the input end of the power converter 1a. The filtering module 2 is used to filter the input voltage Ug to generate a capacitor voltage Uc, and the filtering module 2 may include, but is not limited to, a filtering capacitor C1. The first inductor L1 is electrically connected in series with the switching circuit 3 and then electrically connected in parallel with the filtering module 2. The switching circuit 3 is electrically connected to the output end of the power converter 1a and includes at least one switching component. The switching circuit 3 receives the capacitor voltage Uc via the first inductor L1 and converts the capacitor voltage Uc into the output voltage Vo by the switching operation of at least one switching component and outputs it to the output end of the power conversion device 1a.

[0070] The control unit 4 is electrically connected to the switching circuit 3, the first inductor L1, and the filtering module 2, and is used to detect the respective operating parameters of the filtering module 2, the first inductor L1, and the switching circuit 3, and control the switching operation of the switching components of the switching circuit 3 according to the detection results. The above-mentioned operating parameters may include, but are not limited to, the capacitor voltage Uc of the filtering capacitor C1 of the filtering module 2, the inductor current iL1 flowing through the first inductor L1, and the output voltage Vo output by the switching circuit 3, etc. The control unit 4 includes a voltage loop unit 40, a multi-stage high-frequency filter 41, a current compensation module 42, and a driving module 43.

[0071] The voltage loop unit 40 is electrically connected to the output end of the power converter 1a and is used to detect the output voltage Vo of the power converter 1a and output a voltage compensation signal Vloop according to the output voltage Vo and the first voltage reference signal Vref. The multi-stage high-frequency filter 41 is electrically connected to the filtering module 2 and is used to receive the voltage signal of the filtering module 2, such as the capacitor voltage Uc of the filtering capacitor C1, and perform filtering to output a filtered signal UHS.

[0072] The current compensation module 42 is electrically connected to the filtering module 2, the first inductor L1, and the voltage loop unit 40, and is used to receive the voltage signal (capacitor voltage Uc of the filtering capacitor C1) of the filtering module 2, the inductor current iL1 flowing through the first inductor L1, and the voltage compensation signal Vloop, and correspondingly output a current compensation signal iloop.

[0073] The driving module 43 is electrically connected to the multi-stage high-frequency filter 41, the current compensation module 42, and the switching circuit 3, and is used to receive the first control signal Vs1 formed by superimposing the filtered signal UHS and the current compensation signal iloop, and correspondingly output the second control signal Vs2 to control the switching operation of the switching components of the switching circuit 3, where the second control signal Vs2 is used for the duty cycle of the switching components of the switching circuit 3.

[0074] Please refer to Figure 1 again. The control method of this case includes the following steps.

[0075] Step S1: Provide a voltage loop unit 40. The voltage loop unit 40 is electrically connected to the output terminal of the power converter 1a, and is used to detect the output voltage Vo of the power converter 1a, and output a voltage compensation signal Vloop according to the output voltage Vo and the first voltage reference signal Vref.

[0076] Step S2: Provide a multi-stage high-frequency filter 41. The multi-stage high-frequency filter 41 is electrically connected to the filtering module 2, and is used to receive the voltage signal of the filtering module 2 and perform filtering to output the filtered signal UHS.

[0077] Step S3: Provide a current compensation module 42. The current compensation module 42 is electrically connected to the filtering module 2, the first inductor L1, and the voltage loop unit 40, and is used to receive the voltage signal of the filtering module 2, the inductor current iL1 flowing through the first inductor L1, and the voltage compensation signal Vloop, and correspondingly output the current compensation signal iloop.

[0078] Step S4: Superimpose the filtered signal UHS and the current compensation signal iloop to obtain the first control signal Vs1.

[0079] Step S5: Provide a driving module 43. The driving module 43 is electrically connected to the multi-stage high-frequency filter 41, the current compensation module 42, and the switching circuit 3, and is used to receive the first control signal Vs1 formed by superimposing the filtered signal UHS and the current compensation signal iloop, and correspondingly output the second control signal Vs2 to control the switching operation of the switching components of the switching circuit 3, where the second control signal Vs2 is used to control the duty cycle of the switching components of the switching circuit 3.

[0080] As can be seen from the above, since the control method of this case uses the control method of grid voltage feedforward, the operations of identification and switching in the traditional identification method are eliminated, and at the same time, the background harmonics of the grid voltage are suppressed to enhance the dynamic response ability of the grid. In addition, the control method of this case adds the technology of using a multi-stage high-frequency filter for filtering in the control method of grid voltage feedforward, so it can effectively retain low-frequency signals and filter out high-frequency signal disturbances during control, making the effect of suppressing the background harmonics of the grid voltage better.

[0081] In some embodiments, the voltage loop unit 40 includes a first PI regulator 400 ( Figure 3 labeled as Gva, where Gva is the transfer function of the first PI regulator 400), and the first PI regulator 400 is electrically connected to the output terminal of the power converter 1a for detecting the output voltage Vo of the power converter 1a and outputting a voltage compensation signal Vloop according to the output voltage Vo and the first voltage reference signal Vref.

[0082] In some embodiments, the current compensation module 42 includes a phase-locked loop unit 420. The phase-locked loop unit 420 is electrically connected to the filter module 2 for receiving the voltage signal of the filter module 2 and correspondingly outputting a phase angle signal θ and a cosine signal COSθ. The phase-locked loop unit 420 includes a first integrator 421, a coordinate conversion unit 422, a second PI regulator 423, a second integrator 424, and a calculation unit 425 that are electrically connected in sequence. The first integrator 421 ( Figure 3 labeled as SGOI generator, indicating that the first integrator 421 can be but is not limited to a second-order generalized integrator generator) is used to convert the voltage signal of the filter module 2 into a set of orthogonal signals V`, qV`. The coordinate conversion unit 422 ( Figure 3 labeled as Park transform, indicating that the coordinate conversion unit 422 performs coordinate conversion in the Park transform manner) is used to convert the set of orthogonal signals V`, qV` provided by the first integrator 421 into a d-axis voltage signal Vd and a q-axis voltage signal Vq according to the phase angle signal θ. The second PI regulator 423 ( Figure 3 labeled as PI, indicating that the second PI regulator 423 can be but is not limited to a proportional and integral regulator) is used to receive the q-axis voltage signal Vq and the second voltage reference signal Vqref and output a frequency offset ΔW according to the difference Δq between the q-axis voltage signal Vq and the second voltage reference signal Vqref. The second integrator 424 ( Figure 3 labeled as ∫, indicating that the second integrator 424 performs an integration operation) is used to receive the frequency offset ΔW and the nominal frequency Wn and output a phase angle signal θ according to the superposition amount W of the frequency offset ΔW and the nominal frequency Wn. The calculation unit 425 ( Figure 3 labeled as COS, indicating that the calculation unit 425 is used to generate a cosine signal) is used to output a cosine signal cosθ according to the phase angle signal θ, where the amplitude of the cosine signal cosθ is 1.

[0083] In some embodiments, the current compensation module 42 includes a current loop unit 426. The current loop unit 426 includes a multiplier 427 and a third PI regulator 428 that are electrically connected in sequence. The multiplier 427 ( Figure 3Marked with X, representing a multiplication operation) is electrically connected to the calculation unit 425 and the voltage loop unit 40, and is used to multiply the cosine signal cosθ output by the calculation unit 425 and the voltage compensation signal Vloop output by the voltage loop unit 40 to output a current reference signal iLref. The third PI regulator 428( Figure 3 Marked with Gca, and Gca is the transfer function of the third PI regulator 428) is electrically connected to the first inductor L1, and is used to receive the current reference signal iLref and the inductor current iL1, and correspondingly output a current compensation signal iloop.

[0084] In some embodiments, the driving module 43 includes a modulation circuit 430 and a driving circuit 431. The modulation circuit 430( Figure 3 Marked with SWPM, representing that the modulation circuit 430 is a sinusoidal pulse width modulation) is electrically connected to the current compensation module 42 and the multi-order high-frequency filter 41, and is used to receive the first control signal Vs1 and correspondingly output a modulation signal Vp. The driving circuit 431 is electrically connected to the modulation circuit 430 and the switching circuit 3, and is used to receive the modulation signal Vp and correspondingly output a second control signal Vs2 to control the switching operation of the switching components of the switching circuit 3.

[0085] In some embodiments, the power converter 1a includes a PFC circuit 5, which is electrically connected to the filtering module 2 and the output terminal of the power converter 1a, and the PFC circuit 5 includes a first inductor L1 and a switching circuit 3. In addition, the multi-order high-frequency filter 41 includes a second-order generalized integrator, and the cut-off frequency of the second-order generalized integrator can be but is not limited to 1500 Hz, and Figure 3 wherein, the transfer function of the multi-order high-frequency filter 41 is marked where ωO is the resonant angular frequency, K is the gain value, and s is the complex frequency. In other embodiments, the output terminal of the power converter 1a of the power conversion device 1 can be electrically connected in parallel with the bus capacitor Cbus. In some embodiments, the power converter 1a further includes a second inductor L2, which is electrically connected between the input terminal of the power converter 1a and the first inductor L1.

[0086] Please refer to Figure 4A 、 Figure 4B 、 Figure 4C 、 Figure 5A 、 Figure 5B and Figure 5C where Figure 4A is the current simulation diagram at the input terminal of the power conversion device when the traditional power conversion device adopts the grid voltage feedforward control method and uses a single-phase phase-locked loop as the feedforward, Figure 4BThe current simulation diagram at the input end of a power conversion device when the traditional power conversion device adopts the grid voltage feedforward control method and uses a first-order low-pass filter as the feedforward. Figure 4C The current simulation diagram at the input end of the power conversion device in this case when the grid voltage feedforward control method is adopted and a multi-order high-pass filter is used as the feedforward. Figure 5A The current harmonic spectrum analysis diagram when the traditional power conversion device adopts the grid voltage feedforward control method and uses a single-phase phase-locked loop as the feedforward. Figure 5B The current harmonic spectrum analysis diagram when the traditional power conversion device adopts the grid voltage feedforward control method and uses a first-order low-pass filter as the feedforward. Figure 5 is the current harmonic spectrum analysis diagram when the power conversion device in this case adopts the grid voltage feedforward control method and uses a multi-order high-pass filter as the feedforward. In Figure 4A 、 Figure 4B and Figure 4C The simulation conditions are that the inductance value of the first inductor L1 is 150 uH, the inductance value of the second inductor L2 is 2 mH, the capacitance value of the filter capacitor is 13.2 uF, the input voltage Vin is 220 Vrms, and the power of the power conversion device is 6000 w. From Figure 4A 、 Figure 4B and Figure 4C it can be seen that Figure 4B when using a first-order low-pass filter as the grid voltage feedforward part as shown, the current shows obvious distortion, while Figure 4A when using a single-phase phase-locked loop as the grid voltage feedforward as shown in Figure 4C and when using a multi-order high-pass filter as the grid voltage feedforward as shown, the sinusoidality of the current is better.

[0087] In addition, in Figure 5A 、 Figure 5B and Figure 5C the simulation conditions are that under normal grid conditions, the background harmonics of the grid voltage are increased by 10% for the third harmonic, 5% for the fifth and seventh harmonics respectively, the inductance value of the first inductor L1 is 150 uH, the inductance value of the second inductor L2 is 0, the capacitance value of the filter capacitor C1 is 13.2 uF, the input voltage Vin is 220 Vrms, and the power of the power conversion device is 6000 w. From Figure 5A 、 Figure 5B and Figure 5C it can be seen that Figure 5A when using a single-phase phase-locked loop as the grid voltage feedforward part as shown, it has almost no ability to suppress background harmonics, while Figure 5B when using a first-order low-pass filter as the grid voltage feedforward as shown in Figure 5C and when using a multi-order high-pass filter as the grid voltage feedforward as shown, both can suppress background harmonics, and Figure 5CThe background harmonic suppression effect is significantly better than Figure 5B the background harmonic suppression effect.

[0088] In summary, this case provides a control method for a power converter and a power conversion device. Since the control method for the power converter and the power conversion device uses a control method of grid voltage feedforward, the operations of identification and switching in the traditional identification method are eliminated. In addition, the control method in this case further adds a technology of using a multi-stage high-frequency filter for filtering in the control method of grid voltage feedforward. Therefore, low-frequency signals can be effectively retained during control, high-frequency signal disturbances can be filtered out, and the effect of suppressing background harmonics of the grid voltage is better.

Claims

1. A control method for a power converter, characterized in that: The power converter is electrically connected to a power grid, and the power converter includes a filter module, a first inductor and a switch circuit, wherein the filter module is connected in parallel with the power grid, the switch circuit is connected in series with the first inductor and then connected in parallel with the filter module, and the control method includes: Providing a voltage loop unit, the voltage loop unit is electrically connected to an output terminal of the power converter, and is used to detect an output voltage of the power converter, and output a voltage compensation signal according to the output voltage and a first voltage reference signal; Providing a multi-order high-frequency filter, the multi-order high-frequency filter is electrically connected to the filter module, and is used to receive a voltage signal from the filter module and filter it to output a filtered signal; Providing a current compensation module, electrically connected to the filter module, the first inductor and the voltage ring unit, for receiving the voltage signal of the filter module, an inductor current flowing through the first inductor and the voltage compensation signal, and correspondingly outputting a current compensation signal; superimposing the filtered signal and the current compensation signal to obtain a first control signal; as well as A driving module is provided, which is electrically connected to the multi-order high-frequency filter, the current compensation module and the switching circuit, and is used to receive the first control signal and output a second control signal accordingly, wherein the second control signal is used to control the duty cycle of the switching component in the switching circuit.

2. The control method according to claim 1, characterized in that: The voltage loop unit includes a first PI regulator, which is electrically connected to the output end of the power converter and is used to detect the output voltage of the power converter and output the voltage compensation signal according to the output voltage and the first voltage reference signal.

3. The control method according to claim 1, characterized in that: The current compensation module includes a phase-locked loop unit, which is electrically connected to the filter module and is used to receive the voltage signal of the filter module and output a phase angle signal and a cosine signal accordingly.

4. The control method according to claim 3, characterized in that: The phase-locked loop unit comprises a first integrator, a coordinate conversion unit, a second PI regulator, a second integration unit and a first calculation unit which are electrically connected in sequence; The first integrator is used to convert the voltage signal of the filtering module into a set of orthogonal signals; The coordinate conversion unit is used to convert the group of orthogonal signals into a d-axis voltage signal and a q-axis voltage signal according to the phase angle signal; The second PI regulator is used to receive the q-axis voltage signal and a second reference signal, and output a frequency offset accordingly; The second integrator is used to receive the frequency offset and a nominal frequency, and output the phase angle signal accordingly; and The first calculation unit is used to obtain the cosine signal according to the phase angle signal, wherein the amplitude of the cosine signal is 1.

5. The control method according to claim 4, characterized in that: The current compensation module comprises a current loop unit, and the current loop unit comprises a multiplier and a third PI regulator electrically connected in sequence, wherein the multiplier is used to multiply the cosine signal and the voltage compensation signal to output a current reference signal; The third PI regulator is used to receive the current reference signal and the inductor current, and output the current compensation signal accordingly.

6. The control method according to claim 1, characterized in that: The driving module comprises: a modulation circuit, electrically connected to the current compensation module and the multi-order high-frequency filter, configured to receive the first control signal and output a modulation signal accordingly; and A driving circuit is electrically connected to the switch circuit, and is used to receive the modulation signal and output a second control signal accordingly.

7. The control method according to claim 1, characterized in that: The power converter includes a PFC circuit. The PFC circuit includes the first inductor and the switch circuit.

8. The control method according to claim 1, characterized in that: The multi-order high frequency filter includes a second-order generalized integrator.

9. The control method according to claim 1, characterized in that: The filter module includes a filter capacitor.

10. The control method according to claim 1, characterized in that: The output terminal of the power converter is connected in parallel with a bus capacitor.

11. A power conversion device, characterized in that: The power conversion device comprises the power converter as claimed in claim 1, as well as A control unit, the control unit comprising: a voltage loop unit, electrically connected to an output terminal of the power converter, for detecting an output voltage of the power converter, and outputting a voltage compensation signal according to the output voltage and a first voltage reference signal; a multi-order high-frequency filter, electrically connected to the filter module, for receiving a voltage signal from the filter module and filtering it to output a filtered signal; a current compensation module, electrically connected to the filter module, the first inductor and the voltage loop unit, configured to receive the voltage signal of the filter module, an inductor current flowing through the first inductor and the voltage compensation signal, and output a current compensation signal accordingly; A driving module is electrically connected to the multi-order high-frequency filter, the current compensation module and the switching circuit, and is used to receive a first control signal formed by superimposing the filter signal and the current compensation signal, and output a second control signal accordingly, wherein the second control signal is used to control the duty cycle of the switching component in the switching circuit.

12. The power conversion device according to claim 11, characterized in that: The voltage loop unit includes a first PI regulator, which is electrically connected to the output end of the power converter and is used to detect the output voltage of the power converter and output the voltage compensation signal according to the output voltage and the first voltage reference signal.

13. The power conversion device according to claim 11, characterized in that: The current compensation module includes a phase-locked loop unit, which is electrically connected to the filter module and is used to receive the voltage signal of the filter module and output a phase angle signal and a cosine signal accordingly.

14. The power conversion device according to claim 13, characterized in that: The phase-locked loop unit comprises a first integrator, a coordinate conversion unit, a second PI regulator, a second integration unit and a first calculation unit which are electrically connected in sequence; The first integrator is used to convert the voltage signal of the filtering module into a set of orthogonal signals; The coordinate conversion unit is used to convert the group of orthogonal signals into a d-axis voltage signal and a q-axis voltage signal according to the phase angle signal; The second PI regulator is used to receive the q-axis voltage signal and a second reference signal, and output a frequency offset accordingly; The second integrator is used to receive the frequency offset and a nominal frequency, and output the phase angle signal accordingly; and The first calculation unit is used to obtain the cosine signal according to the phase angle signal, wherein the amplitude of the cosine signal is 1.

15. The power conversion device according to claim 14, characterized in that: The current compensation module comprises a current loop unit, and the current loop unit comprises a multiplier and a third PI regulator electrically connected in sequence, wherein the multiplier is used to multiply the cosine signal and the voltage compensation signal to output a current reference signal; The third PI regulator is used to receive the current reference signal and the inductor current, and output the current compensation signal accordingly.

16. The power conversion device according to claim 11, characterized in that: The driving module comprises: a modulation circuit, electrically connected to the current compensation module and the multi-order high-frequency filter, configured to receive the first control signal and output a modulation signal accordingly; and A driving circuit is electrically connected to the switch circuit, and is used to receive the modulation signal and output a second control signal accordingly.

17. The power conversion device according to claim 11, characterized in that: The power converter includes a PFC circuit. The PFC circuit includes the first inductor and the switch circuit.

18. The power conversion device according to claim 11, characterized in that: The multi-order high frequency filter includes a second-order generalized integrator.

19. The power conversion device according to claim 11, characterized in that: The filter module includes a filter capacitor.

20. The power conversion device according to claim 11, characterized in that: The output terminal of the power converter is connected in parallel with a bus capacitor.

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