Method, device and medium for suppressing voltage fluctuation of electrolytic capacitor-free Vienna rectifier

Abstract

The present invention relates to the technical field of Vienna rectifier modulation, and in particular to a method, device, and medium for suppressing voltage fluctuations of a Vienna rectifier without an electrolytic capacitor. The method comprises: collecting an output voltage signal and a load current at an output end of the rectifier in real time; adjusting an initial switching frequency, an initial duty cycle, and an initial dead time respectively to obtain a new mapping relationship between the switching frequency, the new duty cycle, and the load current, and a new dead time; using an adaptive control algorithm to calculate a control signal based on the obtained mapping relationship between the new switching frequency, the new duty cycle, and the load current, and the new dead time, and driving the rectifier based on the control signal. The present invention can perform dynamic adjustments based on real-time voltage fluctuations to achieve precise regulation and optimization of the rectifier output voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of Vienna rectifier modulation, and in particular to a method, device and medium for suppressing voltage fluctuation of an electrolytic capacitor-free Vienna rectifier. Background Art

[0002] In the field of power electronics, rectifiers are key components for converting alternating current (AC) to direct current (DC). Traditional rectifiers typically use electrolytic capacitors to smooth the output voltage, but these capacitors suffer from short lifespans, temperature susceptibility, and large voltage fluctuations. Consequently, rectifiers without electrolytic capacitors have emerged. While some approaches to rectifiers without electrolytic capacitors have attempted to improve voltage fluctuations by adding more passive components, such as inductors and resistors, these solutions often increase circuit complexity and cost.

[0003] Based on this, Chinese patent publication number CN114884325B discloses a hybrid modulation method for suppressing midpoint voltage fluctuations in an electrolytic capacitor-free Vienna rectifier. This method uses dual carriers to drive the Vienna rectifier, eliminating sector judgment and angle calculations and reducing the computational burden on the controller. However, the adjustment process is still relatively complex and cannot be dynamically adjusted based on real-time voltage fluctuations, making it impossible to accurately regulate and optimize the rectifier output voltage. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method, device and medium for suppressing voltage fluctuations in a Vienna rectifier without electrolytic capacitors, which can dynamically adjust according to real-time voltage fluctuations to achieve precise regulation and optimization of the rectifier output voltage.

[0005] In order to achieve the above objectives / solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a method for suppressing voltage fluctuations in a Vienna rectifier without an electrolytic capacitor, the method comprising:

[0007] Real-time acquisition of output voltage signal and load current at the rectifier output end;

[0008] Perform preliminary processing on the collected output voltage signal to obtain the voltage fluctuation frequency;

[0009] The initial switching frequency is adjusted according to the voltage fluctuation frequency to obtain a new switching frequency;

[0010] The initial duty cycle is adjusted according to the voltage fluctuation amplitude to obtain a new duty cycle, and a mapping relationship between the new duty cycle and the load current is established;

[0011] The initial dead time is adjusted according to the load current and the load rated current to obtain a new dead time;

[0012] An adaptive control algorithm is used to calculate a control signal based on the obtained new switching frequency, a new mapping relationship between the duty cycle and the load current, and a new dead time, and the rectifier is driven according to the control signal.

[0013] In combination with the first aspect, optionally, performing preliminary processing on the collected output voltage signal to obtain the voltage fluctuation frequency includes:

[0014] Filtering the collected output voltage signal to obtain a filtered voltage signal;

[0015] Perform Fourier transform on the filtered voltage signal to obtain the frequency spectrum;

[0016] The frequency point with the largest amplitude is determined by the frequency spectrum, which is the voltage fluctuation frequency.

[0017] In combination with the first aspect, optionally, the initial switching frequency is adjusted according to the voltage fluctuation frequency to obtain a new switching frequency, which is expressed as follows:

[0018] ;

[0019] And the upper and lower limits of the switching frequency are constrained, and the formula is expressed as:

[0020] , ;

[0021] in, is the initial switching frequency, is the voltage fluctuation frequency, is the new switching frequency, is the minimum switching frequency, is the maximum switching frequency.

[0022] In combination with the first aspect, optionally, the new switching frequency needs to meet the following requirements:

[0023] .

[0024] In combination with the first aspect, optionally, adjusting the initial duty cycle according to the voltage fluctuation amplitude to obtain a new duty cycle, and establishing a mapping relationship between the new duty cycle and the load current includes:

[0025] Calculate the voltage fluctuation amplitude, the formula is expressed as:

[0026] ;

[0027] in, is the current output voltage signal, is the reference voltage, is the voltage fluctuation amplitude;

[0028] The initial duty cycle is adjusted according to the voltage fluctuation amplitude to obtain a new duty cycle, which is expressed as:

[0029] ;

[0030] in, is the initial duty cycle, is the new duty cycle;

[0031] A new mapping relationship between duty cycle and load current is established, and the formula is expressed as:

[0032] ;

[0033] in, is the proportionality coefficient, is the load current variation.

[0034] In combination with the first aspect, optionally, the initial dead time is adjusted according to the load current and the load rated current to obtain a new dead time, which is expressed as follows:

[0035] ;

[0036] And the upper and lower limits of the dead time are constrained, and the formula is expressed as:

[0037] , ;

[0038] in, is the load current, is the load rated current, is the initial dead time, is the new dead time, is the minimum dead time, is the maximum dead time.

[0039] In combination with the first aspect, optionally, the new dead time must meet the following requirements:

[0040] .

[0041] In combination with the first aspect, optionally, the adaptive control algorithm is used to calculate based on the obtained new switching frequency, the new mapping relationship between the duty cycle and the load current, and the new dead time to obtain a control signal, which is expressed as follows:

[0042] ;

[0043] in, is the new switching frequency, is the mapping relationship between the new duty cycle and load current, is the new dead time.

[0044] In a second aspect, the present invention provides a device for suppressing voltage fluctuations of a Vienna rectifier without an electrolytic capacitor, the device comprising:

[0045] Acquisition module: used to collect the output voltage signal and load current of the rectifier output end in real time;

[0046] Preliminary processing module: used to perform preliminary processing on the collected output voltage signal to obtain the voltage fluctuation frequency;

[0047] Switching frequency module: used to adjust the initial switching frequency according to the voltage fluctuation frequency to obtain a new switching frequency;

[0048] The duty cycle module is used to adjust the initial duty cycle according to the voltage fluctuation amplitude to obtain a new duty cycle and establish a mapping relationship between the new duty cycle and the load current;

[0049] The dead time module is used to adjust the initial dead time according to the load current and the load rated current to obtain a new dead time;

[0050] The control algorithm module is used to use an adaptive control algorithm to calculate according to the obtained new switching frequency, the new mapping relationship between the duty cycle and the load current, and the new dead time, to obtain a control signal, and drive the rectifier according to the control signal.

[0051] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the methods described in the first aspect.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] By real-time acquisition of the output voltage signal and load current at the rectifier output end, combined with dynamic adjustment of the voltage fluctuation frequency, duty cycle and dead time, multi-parameter collaborative optimization is achieved, effectively improving the voltage fluctuation suppression effect. Through the adaptive control algorithm, the optimal control signal is generated in real time according to the changes in the real-time acquired data, realizing closed-loop control, effectively smoothing the output voltage, and improving system stability and dynamic response speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a step diagram of the present invention. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. Unless there is a conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0056] In the description of the present invention, if “first” or “second” is described, it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0057] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Example 1:

[0058] like Figure 1 As shown, the present invention provides a method for suppressing voltage fluctuations of a Vienna rectifier without electrolytic capacitors, comprising:

[0059] Step 1: Real-time acquisition of the output voltage signal and load current at the rectifier output end, performed at fixed intervals;

[0060] In some embodiments, a voltage sensor is installed at the output end of the Vienna rectifier to collect the output voltage signal, and the accuracy of the voltage sensor is within 0.1% and the sampling frequency is not less than 10 kHz;

[0061] In some embodiments, the load current can be collected by connecting a shunt resistor in series in the load loop or using a non-invasive Hall sensor in conjunction with a differential amplifier;

[0062] In some examples, the voltage sensor / Hall sensor has sensor noise, so the voltage / current signal output by the voltage sensor / Hall sensor is represented as the sum of the voltage / current signal and the sensor noise signal, and the voltage / current signal output by the sensor is also processed subsequently.

[0063] Step 2: Perform preliminary processing on the collected output voltage signal to obtain the voltage fluctuation frequency, specifically including:

[0064] Filtering the collected output voltage signal to obtain a filtered voltage signal. In some embodiments, a low-pass filter is used to remove high-frequency noise interference, and the cutoff frequency is set to 500 Hz;

[0065] Perform Fourier transform on the filtered voltage signal to obtain the frequency spectrum;

[0066] The frequency point with the largest amplitude is determined by the frequency spectrum, which is the voltage fluctuation frequency.

[0067] In this step, the main frequency of voltage fluctuation is accurately extracted through filtering and Fourier transform to avoid noise interference, provide a reliable basis for switching frequency adjustment, and improve the targetedness of fluctuation suppression.

[0068] Step 3: Adjust the initial switching frequency according to the voltage fluctuation frequency to obtain a new switching frequency.

[0069] The formula is:

[0070] ;

[0071] And the upper and lower limits of the switching frequency are constrained, and the formula is expressed as:

[0072] , ;

[0073] in, is the initial switching frequency, is the voltage fluctuation frequency, is the new switching frequency, is the minimum switching frequency, is the maximum switching frequency.

[0074] At the same time, the new switching frequency must meet the following requirements:

[0075] .

[0076] In this step, the switching frequency is linearly adjusted based on the voltage fluctuation frequency, so that the switching frequency dynamically tracks the fluctuation changes and effectively blocks the fluctuation propagation path; by constraining the upper and lower limits of the switching frequency, device losses and electromagnetic interference caused by high-frequency switching are avoided, taking into account both efficiency and performance.

[0077] Step 4: Adjust the initial duty cycle according to the voltage fluctuation amplitude to obtain a new duty cycle, and establish a mapping relationship between the new duty cycle and the load current, including:

[0078] Calculate the voltage fluctuation amplitude, the formula is expressed as:

[0079] ;

[0080] in, is the current output voltage signal, is the reference voltage, The voltage fluctuation amplitude is set according to the actual situation, and no excessive restrictions are made here;

[0081] The initial duty cycle is adjusted according to the voltage fluctuation amplitude to obtain a new duty cycle, which is expressed as:

[0082] ;

[0083] in, is the initial duty cycle, is the new duty cycle;

[0084] A new mapping relationship between duty cycle and load current is established, and the formula is expressed as:

[0085] ;

[0086] in, is the proportionality coefficient, is the load current change, specifically the difference between the current load current and the load current in the previous cycle.

[0087] In this step, the duty cycle is corrected in real time according to the voltage fluctuation amplitude, the voltage deviation is quickly compensated, and the adjustment time is shortened. By establishing a linear mapping between the duty cycle and the load current change, the advance compensation of the load transient change is achieved, and the voltage drop or overshoot caused by the current mutation is suppressed.

[0088] Step 5: Adjust the initial dead time according to the load current and the load rated current to obtain the new dead time. The formula is:

[0089] ;

[0090] And the upper and lower limits of the dead time are constrained, and the formula is expressed as:

[0091] , ;

[0092] in, is the load current, is the load rated current, is the initial dead time, is the new dead time, is the minimum dead time, is the maximum dead time.

[0093] At the same time, the new dead time must meet the following requirements:

[0094] .

[0095] In this step, the dead time is dynamically adjusted according to the deviation of the load current from the rated value. The dead time is increased under heavy load to suppress the risk of the switch tube being turned through, and the dead time is reduced under light load to reduce the switching loss. By constraining the dead time range, control failure under extreme working conditions is avoided and system reliability is improved.

[0096] Step 6: Adopt the adaptive control algorithm to calculate the control signal based on the new switching frequency, the new mapping relationship between duty cycle and load current, and the new dead time. The formula is:

[0097] ;

[0098] in, is the new switching frequency, is the mapping relationship between the new duty cycle and load current, is the new dead time.

[0099] The adaptive control algorithm adopts existing technology and will not be described in detail here. In some examples, the response time is adjusted by adjusting the main cycle period of the adaptive control algorithm. In this embodiment, the main cycle period is set to 1ms.

[0100] The resolution of the control signal is not less than 12 bits. The control signal is converted into a drive signal through a drive circuit, and then the rectifier is driven according to the drive signal.

[0101] In this step, an adaptive control algorithm is used based on multivariable inputs such as switching frequency, duty cycle, and dead time to achieve precise closed-loop control under nonlinear working conditions and further reduce the voltage fluctuation amplitude. Example 2:

[0102] In a second aspect, the present invention provides a device for suppressing voltage fluctuations of a Vienna rectifier without an electrolytic capacitor, the device comprising:

[0103] Acquisition module: used to collect the output voltage signal and load current of the rectifier output end in real time;

[0104] Preliminary processing module: used to perform preliminary processing on the collected output voltage signal to obtain the voltage fluctuation frequency;

[0105] Switching frequency module: used to adjust the initial switching frequency according to the voltage fluctuation frequency to obtain a new switching frequency;

[0106] The duty cycle module is used to adjust the initial duty cycle according to the voltage fluctuation amplitude to obtain a new duty cycle and establish a mapping relationship between the new duty cycle and the load current;

[0107] The dead time module is used to adjust the initial dead time according to the load current and the load rated current to obtain a new dead time;

[0108] The control algorithm module is used to use an adaptive control algorithm to calculate according to the obtained new switching frequency, the new mapping relationship between the duty cycle and the load current, and the new dead time, to obtain a control signal, and drive the rectifier according to the control signal.

[0109] The voltage fluctuation suppression device for a Vienna rectifier without electrolytic capacitors provided in an embodiment of the present invention can execute the voltage fluctuation suppression method for a Vienna rectifier without electrolytic capacitors provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method. Example 3:

[0110] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method steps described in the first embodiment are implemented.

[0111] The voltage fluctuation suppression device for a Vienna rectifier without electrolytic capacitors provided in an embodiment of the present invention can execute the voltage fluctuation suppression method for a Vienna rectifier without electrolytic capacitors provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0112] Those skilled in the art will appreciate that the embodiments of the present application may provide methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0113] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0114] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0116] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for suppressing voltage fluctuations in a Vienna rectifier without electrolytic capacitors, characterized in that: The method comprises: Real-time acquisition of output voltage signal and load current at the rectifier output end; Perform preliminary processing on the collected output voltage signal to obtain the voltage fluctuation frequency; The initial switching frequency is adjusted according to the voltage fluctuation frequency to obtain a new switching frequency; The initial duty cycle is adjusted according to the voltage fluctuation amplitude to obtain a new duty cycle, and a mapping relationship between the new duty cycle and the load current is established; Calculate the voltage fluctuation amplitude, the formula is expressed as: ； in, is the current output voltage signal, is the reference voltage, is the voltage fluctuation amplitude; The initial duty cycle is adjusted according to the voltage fluctuation amplitude to obtain a new duty cycle, which is expressed as: ； in, is the initial duty cycle, is the new duty cycle; A new mapping relationship between duty cycle and load current is established, and the formula is expressed as: ； in, is the proportionality coefficient, is the load current variation; The initial dead time is adjusted according to the load current and the load rated current to obtain a new dead time. The dead time is increased under heavy load to suppress the risk of the switch tube being turned on, and the dead time is reduced under light load to reduce the switching loss. An adaptive control algorithm is used to calculate a control signal based on the obtained new switching frequency, a new mapping relationship between the duty cycle and the load current, and a new dead time, and the rectifier is driven according to the control signal.

2. The method for suppressing voltage fluctuations of a Vienna rectifier without electrolytic capacitor according to claim 1, characterized in that: The preliminarily processing of the collected output voltage signal to obtain the voltage fluctuation frequency includes: Filtering the collected output voltage signal to obtain a filtered voltage signal; Perform Fourier transform on the filtered voltage signal to obtain the frequency spectrum; The frequency point with the largest amplitude is determined by the frequency spectrum, which is the voltage fluctuation frequency.

3. The method for suppressing voltage fluctuation of a Vienna rectifier without electrolytic capacitor according to claim 1, characterized in that: The initial switching frequency is adjusted according to the voltage fluctuation frequency to obtain a new switching frequency, which is expressed as follows: ； And the upper and lower limits of the switching frequency are constrained, and the formula is expressed as: ， ； in, is the initial switching frequency, is the voltage fluctuation frequency, is the new switching frequency, is the minimum switching frequency, is the maximum switching frequency.

4. The method for suppressing voltage fluctuations of a Vienna rectifier without electrolytic capacitor according to claim 3, characterized in that: The new switching frequency must meet the following requirements: 。 5. The method for suppressing voltage fluctuation of a Vienna rectifier without electrolytic capacitor according to claim 1, characterized in that: The initial dead time is adjusted according to the load current and the load rated current to obtain a new dead time, which is expressed as follows: ； And the upper and lower limits of the dead time are constrained, and the formula is expressed as: ， ； in, is the load current, is the load rated current, is the initial dead time, is the new dead time, is the minimum dead time, is the maximum dead time.

6. The method for suppressing voltage fluctuations of a Vienna rectifier without electrolytic capacitor according to claim 5, characterized in that: The new dead time must meet the following requirements: 。 7. The method for suppressing voltage fluctuations of a Vienna rectifier without electrolytic capacitor according to claim 1, characterized in that: The adaptive control algorithm is used to calculate the control signal based on the new switching frequency, the new mapping relationship between the duty cycle and the load current, and the new dead time. The formula is expressed as follows: ； in, is the new switching frequency, is the mapping relationship between the new duty cycle and load current, is the new dead time.

8. A voltage fluctuation suppression device for a Vienna rectifier without electrolytic capacitor, characterized in that: The device comprises: Acquisition module: used to collect the output voltage signal and load current of the rectifier output end in real time; Preliminary processing module: used to perform preliminary processing on the collected output voltage signal to obtain the voltage fluctuation frequency; Switching frequency module: used to adjust the initial switching frequency according to the voltage fluctuation frequency to obtain a new switching frequency; The duty cycle module is used to adjust the initial duty cycle according to the voltage fluctuation amplitude to obtain a new duty cycle and establish a mapping relationship between the new duty cycle and the load current; The dead time module is used to adjust the initial dead time according to the load current and the load rated current to obtain a new dead time; The control algorithm module is used to use an adaptive control algorithm to calculate according to the obtained new switching frequency, the new mapping relationship between the duty cycle and the load current, and the new dead time, to obtain a control signal, and drive the rectifier according to the control signal.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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