Switching frequency control method and device, storage medium and electronic equipment

Abstract

The invention discloses a switching frequency control method and device, a storage medium and electronic equipment, and relates to the technical field of networks. The method comprises the following steps: calculating a three-phase voltage ripple and a three-phase duty ratio according to a reference voltage; calculating flux linkage ripples by using the three-phase voltage ripples and the three-phase duty ratio; the flux linkage ripples are used for representing the action effect of the voltage ripples at each moment in the sampling period; and controlling the switching frequency according to the flux linkage ripples. The action effect of voltage ripples at each moment in a sampling period is represented by defining the flux linkage ripples, external parameters are not depended on, the switching frequency is changed through the difference of the flux linkage ripples, harmonic waves and conducted electromagnetic noise of a system are optimized, and meanwhile the ripples and conducted EMI of the system are improved. The problems that in an existing PWM variable switching frequency control method, the control relation on the switching frequency is generally established depending on additionally-added parameters of an external load, the application range is small, and universality is low are solved.

Description

Technical Field

[0001] This application relates to the field of network technology, specifically to a switching frequency control method, apparatus, storage medium, and electronic device. Background Technology

[0002] PWM (Pulse Width Modulation) is a pulse width modulation technique. In conventional PWM methods, the high-frequency harmonic switching frequency is often fixed to an integer multiple of the switching frequency. This can lead to excessive conducted EMI (Electromagnetic Interference). Related technologies typically employ random switching frequency modulation, which controls the switching frequency to distribute high-frequency harmonics across a wider frequency range, thereby improving conducted EMI. However, most specific control methods are based on load parameters (such as resistive-inductive loads, induction motors, synchronous motors, etc.) or on predictive models based on current or torque ripple. This approach requires additional external load parameters to establish the control relationship with the switching frequency, resulting in significant dependence on load parameters and limited versatility and applicability.

[0003] Therefore, current PWM switching frequency control methods typically rely on the parameters of an additional external load to establish the control relationship for the switching frequency, resulting in limited applicability and low versatility. Summary of the Invention

[0004] In view of this, this application provides a switching frequency control method, apparatus, storage medium, and electronic device, which can improve the current PWM variable switching frequency control method, which usually relies on the parameters of an additional external load to establish the control relationship of the switching frequency, resulting in a limited scope of application and low versatility.

[0005] In a first aspect, this application provides a switching frequency control method, including:

[0006] Calculate the three-phase voltage ripple and three-phase duty cycle based on the reference voltage;

[0007] The flux linkage ripple is calculated using the three-phase voltage ripple and the three-phase duty cycle; the flux linkage ripple is used to characterize the effect of the voltage ripple at each moment within the sampling period.

[0008] The switching frequency is controlled based on the magnetic flux ripple.

[0009] Optionally, controlling the switching frequency based on the flux linkage ripple includes: calculating the maximum value of the flux linkage ripple within the sampling period using the three-phase voltage ripple and the three-phase duty cycle; calculating a set value of the flux linkage ripple using the modulation index; and controlling the switching frequency based on the maximum value of the flux linkage ripple and the set value of the flux linkage ripple.

[0010] Optionally, calculating the maximum value of the flux linkage ripple using the three-phase voltage ripple and the three-phase duty cycle includes: calculating the switching point of the three-phase voltage ripple in the sampling period using the three-phase duty cycle; determining the proportion of each phase in the sampling period based on the switching point; and calculating the flux linkage ripple of each phase in the sampling period based on the proportion of each phase in the sampling period; wherein the maximum value of the flux linkage ripple is obtained from the flux linkage ripple of each phase in the sampling period.

[0011] Optionally, the step of calculating the flux linkage ripple of each phase within the sampling period based on the proportion of each phase in the sampling period includes: determining the duration of each phase based on the proportion of each phase in the sampling period; the duration includes several moments; multiplying the voltage ripple of each phase at each moment in the sampling period by the voltage ripple of each phase at the current moment to obtain the flux linkage ripple of each phase at each moment in the sampling period; and obtaining the flux linkage ripple of each phase in the sampling period based on the set of flux linkage ripples of the same phase at each moment in the sampling period; wherein the voltage ripple of each phase is calculated from the DC bus voltage and the three-phase duty cycle.

[0012] Optionally, the calculation of the flux linkage ripple of each phase within the sampling period based on the proportion of each phase in the sampling period includes:

[0013]

[0014] Where, Δψ a , Δψ b , Δψ c These represent the flux linkage ripple of each phase during the sampling period, u dc T is the DC bus voltage. a T b T c These are the three-phase switching points, and Ts is the sampling period.

[0015] Optionally, the step of calculating the set value of the flux linkage ripple through the modulation index includes: calculating the modulation index based on the reference voltage; establishing a fitting function between the set value of the flux linkage ripple and the modulation index based on a predetermined switching frequency variation range; and calculating the set value of the flux linkage ripple based on the fitting function.

[0016] Optionally, controlling the switching frequency based on the maximum value of the flux linkage ripple and the set value of the flux linkage ripple includes: determining a frequency control factor based on the maximum value of the flux linkage ripple and the set value of the flux linkage ripple; and controlling the switching frequency using the frequency control factor and a preset value of the switching frequency.

[0017] Secondly, this application provides a switching frequency control device, comprising:

[0018] The acquisition unit is configured to calculate the three-phase voltage ripple and three-phase duty cycle based on the reference voltage;

[0019] The calculation unit is configured to calculate the flux linkage ripple using the three-phase voltage ripple and the three-phase duty cycle; the flux linkage ripple is used to characterize the effect of the voltage ripple at each moment within the sampling period.

[0020] The control unit is configured to control the switching frequency based on the flux linkage ripple.

[0021] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the switching frequency control method described in the first aspect.

[0022] Fourthly, this application provides an electronic device, including a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor executes the computer program to implement the switching frequency control method of the first aspect;

[0023] Fifthly, this application provides a computer program product having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the switching frequency control method described in the first aspect.

[0024] By employing the above technical solution, this application provides a switching frequency control method, apparatus, storage medium, and electronic device. First, based on a reference voltage, the three-phase voltage ripple and three-phase duty cycle are calculated. Then, using the three-phase voltage ripple and three-phase duty cycle, the flux linkage ripple is calculated, where the flux linkage ripple characterizes the effect of the voltage ripple at each moment within the sampling period. Next, the switching frequency is controlled based on the flux linkage ripple. Compared with related technologies, this application defines the flux linkage ripple to characterize the effect of the voltage ripple at each moment within the sampling period, without relying on external parameters. It changes the switching frequency through differences in flux linkage ripple, optimizing system harmonics and conducted electromagnetic noise, while simultaneously improving system ripple and conducted EMI. This solves the problem that current PWM variable switching frequency control methods typically rely on additional external load parameters to establish the control relationship for the switching frequency, resulting in limited applicability and low versatility.

[0025] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic flowchart of a switching frequency control method provided in an embodiment of this application is shown;

[0029] Figure 2 A flowchart illustrating another switching frequency control method provided in an embodiment of this application is shown;

[0030] Figure 3 A schematic diagram of a switching frequency control method provided in an embodiment of this application is shown;

[0031] Figure 4 This paper illustrates a three-phase ripple voltage flux linkage ripple diagram within one fundamental cycle, as provided in an embodiment of this application.

[0032] Figure 5 A schematic diagram of a switching frequency control device provided in an embodiment of this application is shown. Detailed Implementation

[0033] To better understand the above-mentioned objectives, features, and advantages of this application, the solutions of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. Furthermore, to gain a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be simplified in their depiction to simplify the drawings.

[0034] To improve upon the limitations of PWM variable switching frequency control methods that rely on additional external load parameters to establish the control relationship for the switching frequency, which suffers from limited applicability and low versatility, this embodiment proposes a new switching frequency control method. For example... Figure 1 As shown, the method includes:

[0035] S101, calculate the three-phase voltage ripple and three-phase duty cycle based on the reference voltage.

[0036] S102, calculate flux linkage ripple using three-phase voltage ripple and three-phase duty cycle.

[0037] The flux linkage ripple is used to characterize the effect of voltage ripple at each moment within the sampling period.

[0038] S103 controls the switching frequency based on the flux linkage ripple.

[0039] In some embodiments, the three-phase voltage in S101 refers to the three voltage waveforms in a three-phase AC power system, with a phase difference of 120 degrees between each phase. Three-phase voltage ripple refers to the fact that in power electronic systems, especially those using pulse width modulation (PWM) technology, the voltage waveform is typically not a perfect sine wave but contains high-frequency fluctuations, which are called ripple. Voltage ripple is commonly used to characterize the error or disturbance between the actual voltage and the reference voltage, and it can be used to assess the stability of the power system, power quality, and equipment reliability. Three-phase duty cycle refers to the ratio of the duration of a high-level (or low-level) state to the total cycle time within a PWM control cycle.

[0040] In some embodiments, S102, flux linkage ripple refers to the fluctuations in the flux linkage in the motor caused by voltage ripple. This embodiment defines a virtual concept of flux linkage ripple, and the magnitude of the flux linkage ripple can characterize the degree of influence of voltage ripple on motor performance. Therefore, the switching frequency can be controlled based on the flux linkage ripple. The flux linkage ripple can be calculated without relying on external parameters, which will be explained later.

[0041] In some embodiments, S103, the switching frequency is controlled according to the flux linkage ripple, specifically through a three-phase electrical control system. Alternatively, the overall calculation process can be applied to a model. By communicating between the model and the system, the model sends the calculation results to the system, which then controls the switching frequency based on the results.

[0042] By employing the above technical solutions, this application provides a switching frequency control method, apparatus, storage medium, and electronic device. In this embodiment, compared with related technologies, it defines flux linkage ripple to characterize the effect of voltage ripple at each moment within the sampling period. It does not rely on external parameters, but changes the switching frequency through differences in flux linkage ripple, optimizing system harmonics and conducted electromagnetic noise, while simultaneously improving system ripple and conducted EMI. This solves the problem that current PWM variable switching frequency control methods typically rely on additional external load parameters to establish the control relationship for the switching frequency, resulting in limited applicability and low versatility.

[0043] Optionally, the switching frequency is controlled based on the flux linkage ripple, including: calculating the maximum value of the flux linkage ripple during the sampling period using the three-phase voltage ripple and the three-phase duty cycle; calculating the set value of the flux linkage ripple through the modulation index; and controlling the switching frequency based on the maximum value of the flux linkage ripple and the set value of the flux linkage ripple.

[0044] In this embodiment, as Figure 2 As shown, first in step S201, the three-phase voltage ripple and three-phase duty cycle are calculated based on the reference voltage. Then, in step S202, the maximum value of the flux linkage ripple is calculated using the three-phase voltage ripple and three-phase duty cycle. Here, the maximum value of the flux linkage ripple refers to the maximum value of the flux linkage ripple for each phase at each moment within the current sampling period. In step S203, the set value of the flux linkage ripple is calculated using the modulation index. Here, the modulation index is...

[0045] Finally, S204 controls the switching frequency based on the maximum value and the set value of the flux linkage ripple. By controlling the switching frequency through the maximum and set values ​​of the flux linkage ripple, the effect of voltage ripple at each moment within the sampling period is characterized. This optimizes the system's harmonics and conducted electromagnetic noise without relying on external parameters, and improves both the system's ripple and conducted EMI.

[0046] Optionally, the maximum value of the flux linkage ripple is calculated using the three-phase voltage ripple and the three-phase duty cycle, including: calculating the switching point of the three-phase voltage ripple in the sampling period using the three-phase duty cycle; determining the proportion of each phase in the sampling period based on the switching point; and calculating the flux linkage ripple of each phase in the sampling period based on the proportion of each phase in the sampling period; wherein the maximum value of the flux linkage ripple is obtained from the flux linkage ripple of each phase in the sampling period.

[0047] This embodiment describes the process of calculating flux linkage ripple. A switching point refers to the moment when switching from one phase (phase A) to another (phase B). Using the known duty cycle and sampling period, the specific locations of these switching points can be calculated. Knowing the switching points allows us to determine the time periods during which each phase is at a high or low level within the sampling period. The proportion of these time periods is the proportion of each phase within the sampling period. Using the known voltage ripple, the flux linkage ripple of each phase within the sampling period can be calculated. The flux linkage ripple is virtual and can be calculated without relying on external parameters. After calculating the flux linkage ripple of each phase within the sampling period, the maximum value among these ripples needs to be found; this is the maximum flux linkage ripple of the entire three-phase system within the sampling period.

[0048] Furthermore, the flux linkage ripple of each phase within the sampling period is calculated based on the proportion of each phase in the sampling period. This includes: determining the duration of each phase based on its proportion in the sampling period; the duration includes several moments; multiplying the voltage ripple of each phase at each moment in the sampling period by the voltage ripple of each phase at the current moment to obtain the flux linkage ripple of each phase at each moment in the sampling period; and obtaining the flux linkage ripple of each phase within the sampling period based on the set of flux linkage ripples of the same phase at each moment in the sampling period. The voltage ripple of each phase is calculated from the DC bus voltage and the three-phase duty cycle.

[0049] In this embodiment, the flux linkage ripple includes the magnitude and duration of the three-phase inverter output voltage ripple, characterizing the effect of the three-phase inverter output voltage ripple within a sampling period. The flux linkage ripple of each phase at each moment within the sampling period is obtained by multiplying the voltage ripple of each phase at the current moment by the current voltage ripple. The method for calculating the voltage ripple at each specific time point is explained.

[0050] Within a sampling period Ts, the voltage ripple is the difference between the reference voltage and the actual voltage. There are two different values ​​for the voltage ripple. Taking phase A as an example, the voltage ripple can be expressed by Formula 1:

[0051]

[0052] In Formula 1, Δu a The flux linkage ripple exhibits a three-segment broken line pattern, with a peak value in each of the first and second halves of the cycle, and their absolute values ​​are equal. The phase A voltage ripple is determined by the average voltage of phase A. Relevant. Furthermore, This is the average value of the three-phase PWM voltage. From DC bus voltage u dc and duty cycle d a d b d c The decision is:

[0053]

[0054] Here, the DC bus voltage u dc Multiplying by the duty cycle means determining the average value of the three-phase PWM voltage based on the DC bus voltage within the corresponding phase voltage duration. After obtaining the voltage ripple, for one sampling period, the peak value Δψ of the three-phase flux linkage ripple is... a , Δψ b , Δψ c It can be calculated as follows:

[0055] Δψ a =Δu a T a

[0056] Δψ b =Δu b T b

[0057] Δψ c =Δu c T c (Formula 3)

[0058] Among them, T a Tb T c These are the switching points of the three-phase PWM, and the switching point is determined by the duty cycle of each phase during the sampling period. a d b d c for:

[0059]

[0060] Combining formulas one through four above, the formula for calculating the maximum value of flux linkage ripple is shown in formula five:

[0061]

[0062] In this formula, the DC bus voltage u dc The periods of each phase (determined by the switching points within the sampling period) are readily available, thus allowing the maximum value of the flux linkage ripple within a sampling period to be obtained without relying on the load parameters of any externally added equipment.

[0063] The maximum actual value of the flux linkage ripple has been calculated above; therefore, it is necessary to calculate the setpoint value of the flux linkage ripple. The setpoint value of the flux linkage ripple is Δψ. set It increases with the increase of the adjustment system.

[0064] Optionally, the set value of flux linkage ripple is calculated by means of modulation, including: calculating the modulation degree based on the reference voltage; establishing a fitting function between the set value of flux linkage ripple and the modulation degree based on a predetermined switching frequency variation range; and calculating the set value of flux linkage ripple based on the fitting function.

[0065] Here is an example, where a setpoint Δψ for flux linkage ripple is established. set The quadratic function of modulation is shown in Formula 6:

[0066] Δψ set =km 2 +b (Formula Six)

[0067] In Formula 6, m is the modulation index, and k and b are constants, set according to actual needs (the range of switching frequency variation). The modulation index is easily obtained from the reference voltage vector, as shown in Formula 7.

[0068]

[0069] In Formula 7, u dc The DC bus voltage, u α and u β For example, when you want to control the switching frequency within ±25%, you can determine the modulation index m using a lookup table or other pre-set method. The mathematical relationship is shown in Formula 8:

[0070]

[0071] Formulas 6 to 8 can serve as a feasible method for calculating the flux linkage ripple setpoint based on the modulation index. In this embodiment, Formulas 6 and 8, as mentioned above, are fitting functions for the flux linkage ripple setpoint and the modulation index. The parameter values ​​in the fitting function can be determined according to actual conditions, such as a predetermined switching frequency variation range, i.e., the range within which the user wants the switching frequency to vary. This allows the user to set different fitting functions according to actual conditions and calculate the flux linkage ripple setpoint. By changing the switching frequency through the difference in flux linkage ripple, the system's harmonics and conducted electromagnetic noise can be optimized.

[0072] Optionally, the ratio of the maximum value of the flux linkage ripple to the set value of the flux linkage ripple is calculated to obtain the frequency control factor; the frequency control factor and the preset value of the switching frequency are used to control the switching frequency.

[0073] The frequency control factor is the maximum value Δψ of the three-phase flux linkage ripple. max and its set value Δψ set The ratio is updated in real time according to Formula Nine:

[0074]

[0075] In Formula 9, f sn For a fixed switching frequency value, f snew The updated switching frequency is adjusted by varying the flux linkage ripple to optimize the system's harmonics and conducted electromagnetic noise, while also improving the system's ripple and conducted EMI.

[0076] Furthermore, Figure 3 A schematic diagram of a switching frequency control method according to this embodiment is shown, and the specific details are as follows:

[0077] Step 1: Calculate the duty cycle d of the three-phase PWM based on the reference voltage vector (a continuous physical quantity). a d b d c The duty cycle is used to calculate the voltage ripple (characterizing error), and then the ripple flux linkage Δψ is calculated. a , Δψ b , Δψ c The virtual flux linkage ripple includes the magnitude and duration of the output voltage ripple of the three-phase inverter, characterizing the effect of the output voltage ripple of the three-phase inverter within a sampling period.

[0078] Within a sampling period Ts, the voltage ripple is the difference between the reference voltage and the actual voltage. There are two different values ​​for the voltage ripple. Taking phase a as an example, the voltage ripple can be expressed by the following formula.

[0079]

[0080] The flux linkage ripple exhibits a three-segment broken line pattern, with one peak value in the first half of the cycle and one in the second half, and their absolute values ​​are equal. For one switching cycle, the peak value Δψ of the three-phase flux linkage ripple is... a , Δψ b , Δψ c It can be calculated as follows:

[0081] Δψ a =Δu a T a

[0082] Δψ b =Δu b T b

[0083] Δψ c =Δu c T c

[0084] Among them, T a T b T c These are the switching points for the three-phase PWM. This is the average value of the three-phase PWM voltage. From DC bus voltage u dc and duty cycle d a d b d c The decision is:

[0085]

[0086] Where, d a d b d c for:

[0087]

[0088] In conclusion:

[0089]

[0090] Therefore, it can be seen that the calculation process of flux linkage ripple characterizes the harmonic magnitude of the input system without requiring load parameters. Thus, it does not rely on external parameters to establish the control relationship of the switching frequency, solving the problems of limited application range and low versatility.

[0091] in, Figure 4 The diagram illustrates the flux linkage ripple of the three-phase ripple voltage within one fundamental frequency cycle of this embodiment. Specifically, it shows the volt-second product of the three-phase ripple voltage within one fundamental frequency cycle. Taking a 5Hz fundamental frequency cycle as an example, it can be seen that within one fundamental frequency cycle, the magnitudes of the three-phase flux linkage ripple are not equal, and the amplitude of the volt-second product of the ripple voltage in each phase changes in real time, ranging from approximately 0.15 to 0.22. This characteristic indicates that the volt-second product of the three-phase ripple voltage is non-uniformly distributed over time. This characteristic can be used to increase the switching frequency when the ripple is large and decrease the switching frequency when the ripple is small.

[0092] Step Two: After obtaining the maximum flux linkage ripple value as in Step One, it is necessary to compare it with the set value. Flux linkage ripple set value Δψ set It increases with the increase of the modulation index, therefore a fitting function was established, such as:

[0093] Δψ set =km 2 +b

[0094] Where m is the modulation index, and k and b are constants. The modulation index is calculated according to actual needs as follows:

[0095]

[0096] Step 3: Measure the maximum value Δψ of the three-phase flux linkage ripple. max and its set value Δψ set Real-time updates of switching frequency, such as:

[0097]

[0098] In the formula, f sn For a fixed switching frequency value, f snew This is the updated switching frequency.

[0099] It should be noted that this switching frequency control method can be applied to both resistive-inductive loads and motor loads. When applied to resistive-inductive loads, it optimizes harmonics and THD. By changing the parameters of the resistive-inductive load, this method is compared with other effective techniques, and its current harmonics are less affected by changes in load parameters.

[0100] When applied to motor loads, as shown in Table 1, the conducted EMI spikes of the three technologies were compared. It is shown that the conducted EMI spikes of the present switching frequency control method and the existing variable switching frequency technology are all suppressed compared to the fixed switching frequency technology. The present method has a better suppression effect on conducted EMI.

[0101]

[0102] Table 1. Size of conducted EMI spikes for the three technologies.

[0103] Furthermore, as Figures 1 to 4 The specific implementation of the method shown in this embodiment provides a switching frequency control device, such as... Figure 5 As shown, the device includes: an acquisition unit 501, a calculation unit 502, and a control unit 503.

[0104] The acquisition unit 501 is configured to calculate the three-phase voltage ripple and the three-phase duty cycle based on the reference voltage.

[0105] The calculation unit 502 is configured to calculate the flux linkage ripple using the three-phase voltage ripple and the three-phase duty cycle; the flux linkage ripple is used to characterize the effect of the voltage ripple at each moment within the sampling period.

[0106] Control unit 503 is configured to control the switching frequency based on the flux linkage ripple.

[0107] In specific application scenarios, the control unit 503 is further configured to calculate the maximum value of the flux linkage ripple within the sampling period using the three-phase voltage ripple and the three-phase duty cycle; calculate the set value of the flux linkage ripple through the modulation index; and control the switching frequency according to the maximum value of the flux linkage ripple and the set value of the flux linkage ripple.

[0108] In a specific application scenario, the control unit 503 is further configured to use the three-phase duty cycle to calculate the switching point of the three-phase voltage ripple in the sampling period; determine the proportion of each phase in the sampling period based on the switching point; and calculate the flux linkage ripple of each phase in the sampling period based on the proportion of each phase in the sampling period; wherein the maximum value of the flux linkage ripple is obtained by the flux linkage ripple of each phase in the sampling period.

[0109] In a specific application scenario, the control unit 503 is specifically configured to determine the duration of each phase based on the proportion of each phase in the sampling period; the duration includes several moments; multiply the voltage ripple of each phase at each moment in the sampling period by the voltage ripple of each phase at the current moment to obtain the flux linkage ripple of each phase at each moment in the sampling period; and obtain the flux linkage ripple of each phase in the sampling period based on the set of flux linkage ripples of the same phase at each moment in the sampling period; wherein the voltage ripple of each phase is calculated from the DC bus voltage and the three-phase duty cycle.

[0110] In a specific application scenario, the control unit 503 is specifically configured to calculate the modulation index based on the reference voltage; establish a fitting function between the set value of the flux linkage ripple and the modulation index based on a predetermined switching frequency variation range; and calculate the set value of the flux linkage ripple based on the fitting function.

[0111] In a specific application scenario, the control unit 503 is specifically configured to determine a frequency control factor based on the maximum value of the flux linkage ripple and the set value of the flux linkage ripple; and to control the switching frequency using the frequency control factor and the preset value of the switching frequency.

[0112] It should be noted that other corresponding descriptions of the functional units involved in the switching frequency control device provided in this embodiment can be found in [reference needed]. Figures 1 to 4 The corresponding description in [the document] will not be repeated here.

[0113] Based on the above, Figures 1 to 4 Accordingly, this embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method. Figures 1 to 4 The method shown.

[0114] Based on the above, Figures 1 to 4 Accordingly, this embodiment also provides a computer program product having a computer program stored thereon, which, when executed by a processor, implements the above-described method. Figures 1 to 4 The method shown.

[0115] Based on this understanding, the technical solution of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as CD-ROM, USB flash drive, mobile hard drive, etc.) and includes several instructions to cause a computer device (such as personal computer, server, or network device, etc.) to execute the methods of various implementation scenarios of this application.

[0116] Based on the above, Figures 1 to 4 The method shown, and Figure 5 To achieve the above objectives, this application also provides an electronic device, which can be configured on a computer side, etc. The device includes a storage medium and a processor; the storage medium is used to store a computer program; the processor is used to execute the computer program to achieve the above-described objectives. Figures 1 to 4 The method shown.

[0117] Optionally, the aforementioned physical devices may also include a user interface, a network interface, a camera, radio frequency (RF) circuitry, sensors, audio circuitry, a Wi-Fi module, etc. The user interface may include a display screen, input units such as a keyboard, etc., and optional user interfaces may also include USB interfaces, card reader interfaces, etc. The network interface may optionally include standard wired interfaces, wireless interfaces (such as Wi-Fi interfaces), etc.

[0118] Those skilled in the art will understand that the physical device structure provided in this embodiment does not constitute a limitation on the physical device, and may include more or fewer components, or combine certain components, or have different component arrangements.

[0119] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the hardware and software resources of the aforementioned physical device, supporting the operation of information processing programs and other software and / or programs. The network communication module is used to enable communication between the various components within the storage medium, as well as communication with other hardware and software in the information processing physical device.

[0120] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented using software plus necessary general-purpose hardware platforms, or it can be implemented in hardware. Compared with related technologies, this embodiment defines flux linkage ripple to characterize the effect of voltage ripple at each moment within the sampling period. It does not rely on external parameters, but changes the switching frequency through differences in flux linkage ripple, optimizing the system's harmonics and conducted electromagnetic noise, while also improving both system ripple and conducted EMI. This solves the problem that current PWM variable switching frequency control methods typically rely on additional external load parameters to establish the control relationship for the switching frequency, resulting in limited applicability and low versatility.

[0121] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising" or any other variations thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0122] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features of this application.

[0123] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. As used herein, the term “and / or” means including one or more of the associated listed any and all possible combinations. Additionally, when used in this application, the terms “comprise” and its variations “comprises” and / or “comprising” refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase “comprising a…” does not exclude the presence of additional identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment focuses on describing the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, apparatuses, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0124] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0125] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed units may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0126] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A switching frequency control method, characterized in that, include: Calculate the three-phase voltage ripple and three-phase duty cycle based on the reference voltage; The flux linkage ripple is calculated using the three-phase voltage ripple and the three-phase duty cycle. The flux linkage ripple is used to characterize the effect of the voltage ripple at each moment within the sampling period; The switching frequency is controlled based on the magnetic flux ripple.

2. The method according to claim 1, characterized in that, The step of controlling the switching frequency based on the magnetic flux ripple includes: The maximum value of the flux linkage ripple during the sampling period is calculated using the three-phase voltage ripple and the three-phase duty cycle. The set value of the flux linkage ripple is calculated by adjusting the modulation index; The switching frequency is controlled based on the maximum value of the flux linkage ripple and the set value of the flux linkage ripple.

3. The method according to claim 2, characterized in that, The calculation of the maximum value of the flux linkage ripple using the three-phase voltage ripple and the three-phase duty cycle includes: Using the three-phase duty cycle, calculate the switching point of the three-phase voltage ripple during the sampling period; Based on the switching point, determine the proportion of each phase in the sampling period; The flux linkage ripple of each phase in the sampling period is calculated based on the proportion of each phase in the sampling period. The maximum value of the flux linkage ripple is obtained by measuring the flux linkage ripple of each phase during the sampling period.

4. The method according to claim 3, characterized in that, The calculation based on the proportion of each phase in the sampling period to obtain the flux linkage ripple of each phase in the sampling period includes: The duration of each phase is determined based on the proportion of each phase in the sampling period; the duration includes several moments. Multiply the voltage ripple of each phase at each moment within the sampling period by the voltage ripple of each phase at the current moment to obtain the flux linkage ripple of each phase at each moment within the sampling period. The flux linkage ripple of each phase in the sampling period is obtained by collecting the flux linkage ripple of the same phase at each moment in the sampling period. The voltage ripple of each phase is calculated from the DC bus voltage and the three-phase duty cycle.

5. The method according to claim 4, characterized in that, The calculation based on the proportion of each phase in the sampling period to obtain the flux linkage ripple of each phase in the sampling period includes: Where, Δψ a , Δψ b , Δψ c These represent the flux linkage ripple of each phase during the sampling period, u dc T is the DC bus voltage. a T b T c These are the three-phase switching points, and Ts is the sampling period.

6. The method according to claim 2, characterized in that, The step of calculating the set value of the flux linkage ripple through modulation includes: The modulation index is calculated based on the reference voltage; Based on a predetermined range of switching frequency variation, a fitting function is established between the set value of the flux linkage ripple and the modulation degree. Based on the fitting function, the set value of the flux linkage ripple is calculated.

7. The method according to any one of claims 1 to 6, characterized in that, The step of controlling the switching frequency based on the maximum value of the flux linkage ripple and the set value of the flux linkage ripple includes: The frequency control factor is determined based on the maximum value of the flux linkage ripple and the set value of the flux linkage ripple. The switching frequency is controlled using the frequency control factor and the preset value of the switching frequency.

8. A switching frequency control device, characterized in that, include: The acquisition unit is configured to calculate the three-phase voltage ripple and three-phase duty cycle based on the reference voltage; The calculation unit is configured to calculate the flux linkage ripple using the three-phase voltage ripple and the three-phase duty cycle; the flux linkage ripple is used to characterize the effect of the voltage ripple at each moment within the sampling period. The control unit is configured to control the switching frequency based on the flux linkage ripple.

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

10. A computer program product having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 7.

11. An electronic device, comprising a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 7.

12. A vehicle, characterized in that, include: The apparatus of claim 8, or the electronic device of claim 11.

Images