Electromagnetic interference suppression method and device for PWM signal, electronic equipment and storage medium

Abstract

The invention provides an electromagnetic interference suppression method and device for a PWM signal, electronic equipment and a storage medium, and relates to the technical field of vehicles, and the method comprises the steps: obtaining a PWM signal generated by a drive circuit and an original drive frequency of the PWM signal, the original drive frequency being a higher harmonic frequency corresponding to the PWM signal; at least one first target driving frequency corresponding to the original driving frequency is determined, the first target driving frequency is different from the original driving frequency, the first target driving frequency is any driving frequency in a preset driving range, and the at least one first target driving frequency is not completely the same; and controlling the driving circuit to drive based on the at least one first target driving frequency. According to the invention, the electromagnetic interference of the PWM signal can be effectively suppressed, and the harmfulness of EMI radiation interference is reduced.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a method, device, electronic device and storage medium for suppressing electromagnetic interference of a PWM signal. Background Art

[0002] With the development and popularization of new energy vehicles, automobile electrification and intelligence have become the mainstream trend. Automobiles have changed from traditional means of transportation to a new "mobile third space". On the basis of meeting people's basic travel needs, people's demand for automobile comfort is also increasing. In related technologies, people's demand for automobile comfort is generally met by improving electric adjustment functions including doors, windows, seats, backrests, tailgates, etc. At the same time, the improvement of these required functions will lead to an increase in the demand for DC motor loads and H-bridge drive circuits.

[0003] However, when the switching devices of the H-bridge driving circuit operate in a high-frequency on-off state, the high-frequency fast transient process itself is a source of electromagnetic disturbance. The electromagnetic interference (EMI) signal generated by it has a wide frequency range and a certain amplitude. If the body controller integrates a large number of H-bridge driving circuits, the EMI signal generated by the body controller will become stronger and more complex, and the EMI signal will cause greater electromagnetic interference to the pulse width modulation (PWM) signal. Summary of the invention

[0004] In view of this, the present application provides a method, device, electronic device and storage medium for suppressing electromagnetic interference of a PWM signal, the main purpose of which is to effectively suppress electromagnetic interference to the PWM signal and reduce the harmfulness of EMI radiation interference.

[0005] According to a first aspect of the present application, a method for suppressing electromagnetic interference of a PWM signal is provided, comprising:

[0006] Acquire a PWM signal generated by a driving circuit, and determine an original driving frequency of the PWM signal, wherein the original driving frequency is a higher harmonic frequency corresponding to the PWM signal;

[0007] Determine at least one first target driving frequency corresponding to the original driving frequency, the first target driving frequency is different from the original driving frequency, the first target driving frequency is any driving frequency within a preset driving range, wherein the at least one first target driving frequency is not completely the same;

[0008] Based on the at least one first target driving frequency, the driving circuit is controlled to drive.

[0009] In some embodiments of the present disclosure, controlling the driving circuit to drive based on the at least one first target driving frequency includes:

[0010] If the number of the first target driving frequency is one, controlling the driving circuit to perform the current driving according to the first target driving frequency;

[0011] If there are multiple first target driving frequencies, the driving circuit is controlled to drive with the corresponding first target driving frequencies in sequence within a preset frequency jittering period, wherein the number of driving times within the preset frequency jittering period is the same as the total number of first target driving frequencies.

[0012] In some embodiments of the present disclosure, after controlling the driving circuit to drive based on the at least one first target driving frequency, the method further includes:

[0013] Determine a second target driving frequency corresponding to the original driving frequency during the next driving, the second target driving frequency is different from the original driving frequency, and the second target driving frequency is any driving frequency within a preset driving range;

[0014] The driving circuit is controlled to perform next driving according to the second target driving frequency.

[0015] In some embodiments of the present disclosure, the PWM signal is a square wave signal. After acquiring the PWM signal generated by the driving circuit and before determining the original driving frequency of the PWM signal, the method further includes:

[0016] The conversion time length of the PWM signal corresponding to the high and low level conversion is adjusted, the PWM signal is adjusted from a square wave signal to a sine wave signal, and the sine wave signal is updated to the PWM signal.

[0017] In some embodiments of the present disclosure, in response to the driving circuit being an H-bridge driving circuit, adjusting the conversion duration of the PWM signal corresponding to the high and low level conversions includes:

[0018] Configuring registers in the driving circuit to extend the conversion time of the PWM signal corresponding to high and low level conversions; or

[0019] By adjusting the capacitance value of the filter capacitor in the H-bridge driving circuit, the conversion time of the PWM signal corresponding to the high and low level conversion is prolonged.

[0020] In some embodiments of the present disclosure, the filter capacitor in the H-bridge driving circuit includes:

[0021] An RC filter circuit is provided at the gate position of each MOS tube or the base position of each triode in the H-bridge driving circuit; or

[0022] An X capacitor is arranged at the drain position of the MOS tube or the collector position of the transistor corresponding to the H-bridge driving circuit; or

[0023] A Y capacitor is arranged at the source position of the MOS tube or the emitter position of the transistor in the H-bridge driving circuit.

[0024] According to a second aspect of the present application, there is provided a PWM signal electromagnetic interference suppression device, comprising:

[0025] An acquisition module, used for acquiring a PWM signal generated by a driving circuit, and determining an original driving frequency of the PWM signal, wherein the original driving frequency is a higher harmonic frequency corresponding to the PWM signal;

[0026] a determination module, configured to determine at least one first target driving frequency corresponding to the original driving frequency, wherein the first target driving frequency is different from the original driving frequency, and the first target driving frequency is any driving frequency within a preset driving range, wherein the at least one first target driving frequency is not completely the same;

[0027] The control module is used to control the driving circuit to drive based on the at least one first target driving frequency.

[0028] According to the third aspect of the present disclosure, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method of the aforementioned first aspect.

[0029] According to a fourth aspect of the present disclosure, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to enable a computer to execute the method of the aforementioned first aspect.

[0030] According to a fifth aspect of the present disclosure, a vehicle is provided, comprising: the electronic device as described in the third aspect.

[0031] The electromagnetic interference suppression method, device, electronic device and storage medium of the PWM signal provided by the present disclosure can perform a driving frequency conversion process on the original driving frequency after obtaining the PWM signal generated by the driving circuit and the original driving frequency of the PWM signal, determine at least one first target driving frequency for reducing the electromagnetic interference generated by the original driving frequency, and then control the driving circuit to drive based on the at least one first target driving frequency. The technical solution in the present disclosure can randomly adjust the original driving frequency of the PWM signal within the allowed range, thereby changing the frequency point of the high-order harmonics corresponding to the PWM signal, so that the frequency point of the high-order harmonics is not fixed, and electromagnetic interference cannot be generated at a fixed frequency point, thereby effectively suppressing the electromagnetic interference to the PWM signal and reducing the harmfulness of EMI radiation interference.

[0032] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings herein are incorporated into and constitute a part of the specification, showing embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. It should be understood that the drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure. Among them:

[0034] Figure 1 A flow chart of a method for suppressing electromagnetic interference of a PWM signal provided in an embodiment of the present disclosure;

[0035] Figure 2 A simplified principle block diagram of a detector provided by an embodiment of the present disclosure;

[0036] Figure 3 An example schematic diagram of a broadband noise suppression effect provided by an embodiment of the present disclosure;

[0037] Figure 4 A schematic flow chart of a method for suppressing electromagnetic interference of a PWM signal provided by another embodiment of the present disclosure;

[0038] Figure 5 A schematic diagram of the structure of a PWM signal electromagnetic interference suppression device provided in an embodiment of the present disclosure;

[0039] Figure 6 A schematic diagram of the structure of a PWM signal electromagnetic interference suppression device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0040] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0041] The following describes the electromagnetic interference suppression method, device, electronic device and storage medium of the PWM signal according to the embodiments of the present disclosure with reference to the accompanying drawings.

[0042] In the related technologies, the most widely used DC motor drive is the H-type circuit. PWM control can adjust the direction and speed. The H-bridge drive circuit generally has EMI radiation problems. The EMI signal generated by the H-bridge drive circuit will cause greater electromagnetic interference to the PWM signal. Among them, the H-bridge drive circuit is a typical DC motor control circuit. Because its circuit shape resembles the letter H, it is called "H bridge". It is composed of 4 MOS tubes or 4 triodes with 4 vertical legs, and the motor is the horizontal bar in the H.

[0043] In order to solve the above technical problems, the present disclosure provides a method, device, electronic device and storage medium for suppressing electromagnetic interference of a PWM signal. Figure 1 As shown, an embodiment of the present disclosure provides a method for suppressing electromagnetic interference of a PWM signal, comprising:

[0044] Step 101: Acquire a PWM signal generated by a driving circuit, and determine an original driving frequency of the PWM signal.

[0045] The electromagnetic interference suppression method of the PWM signal disclosed in the present application is applied to a vehicle control system. At least one drive circuit may be arranged in a vehicle computer, and the vehicle control system may suppress electromagnetic interference of the PWM signal generated by the drive circuit.

[0046] The driving circuit includes but is not limited to an H-bridge driving circuit, and may also include other circuits controlled by PWM signals, such as a direct current direct current (DCDC) power supply. In the following embodiments of the present disclosure, the driving circuit is an H-bridge driving circuit as an example to illustrate the technical solution in the present disclosure, which does not constitute a specific limitation.

[0047] As the switching frequency of the switching devices of the PWM technology continues to increase, when the switching devices work in a high-frequency on-off state, the high-frequency rapid transients will cause electromagnetic interference. For the disclosed embodiment, the electronic device can first obtain the PWM signal generated by the driving circuit, and then obtain the original driving frequency of the PWM signal, wherein the original driving frequency is the higher harmonic frequency corresponding to the PWM signal. In order to avoid electromagnetic interference when the driving circuit is driven by the original driving frequency, the original driving frequency of the PWM signal can be adjusted to fluctuate within a certain frequency range, that is, the frequency of the higher harmonics is changed, so that the frequency of the higher harmonics is not fixed, and the driving circuit is driven based on the unfixed driving frequency. Compared with the driving circuit driven by the fixed driving frequency, the electromagnetic interference generated by the driving circuit is smaller, thereby reducing the electromagnetic interference of the higher harmonics, and the rapid frequency jittering makes the receiver unable to detect the electromagnetic noise of the stable frequency and its harmonics within the current scanning bandwidth and scanning time.

[0048] Step 102: determining at least one first target driving frequency corresponding to the original driving frequency, wherein the first target driving frequency is different from the original driving frequency and is any driving frequency within a preset driving range.

[0049] The first target driving frequency is an offset driving frequency that fluctuates within a certain frequency range after the original driving frequency of the PWM signal is subjected to frequency jitter processing, and each first target driving frequency is not exactly the same. For the disclosed embodiment, when performing frequency jitter processing and determining at least one first target driving frequency, the original driving frequency can be randomly adjusted within the frequency jitter range allowed by the product and the chip so that the first target driving frequency falls on a frequency point outside the original driving frequency, thereby reducing the average value (Average) of EMI and making it easier for products with PWM drive to pass the standard.

[0050] The specific implementation principle can be found in Figure 2 The simplified schematic diagram of the detector shown in the figure is based on the peak detector. Detectors such as the average detector and the quasi-peak detector are obtained by adding appropriate weighting functions on the basis of the peak detector. Among them, the average detector adds a low-pass filter (called a video filter) after the peak detector to filter the broadband component. The averaging effect will only appear when the bandwidth of the video filter is lower than the resolution bandwidth. At the same time, the suppression of broadband noise is related to the ratio of the resolution bandwidth to the bandwidth of the video filter. When the resolution bandwidth is determined, the narrower the video bandwidth, the better the broadband noise suppression effect. Taking the International Special Committee on Radio Interference (CISPR) standard B band (0.15kHz~30MHz) as an example, when the resolution bandwidth is 9kHz and the video bandwidth is about 1Hz, the result will be as follows Figure 3As shown, broadband noise will be greatly reduced. Accordingly, for the embodiments of the present disclosure, when the original driving frequency of the PWM signal is processed, the averaging effect of the average value detector can be used, that is, by reducing the average value of EMI, to achieve electromagnetic interference suppression of the PWM signal. The specific strategy is as follows: Before each drive, the software calculates the frequency of the PWM drive, F / k=F0, where F is the original driving frequency, k is the driving range coefficient supported by the chip and product, and F0 is the target driving frequency at the next drive after frequency jittering. Taking the PWM control drive of the motor as an example, the original driving frequency is 20kHz, and the acceptable driving frequency range is 18~20kHz, then the driving range coefficient k is 1~1.11, and this coefficient varies randomly within the range. After the final calculation, the target driving frequency after frequency jittering can be obtained. After the original driving frequency is frequency-jittered, multiple first target driving frequencies different from the original driving frequency can be obtained. Compared with the fixed driving frequency, multiple non-fixed first target driving frequencies can reduce the average value of EMI, and then change the frequency point of the PWM signal corresponding to the higher harmonics, so that the frequency point of the higher harmonics is not fixed and electromagnetic interference cannot be generated at the fixed frequency point, thereby effectively suppressing the electromagnetic interference of the PWM signal and reducing the harmfulness of EMI radiation interference.

[0051] For the embodiment of the present disclosure, when determining the first target driving frequency corresponding to the original driving frequency:

[0052] As a possible implementation manner, a first target driving frequency of the driving circuit in this driving may be determined according to the original driving frequency. For example, the first target driving frequency corresponding to this driving may be determined to be 18 kHz.

[0053] As a possible implementation method, the driving period of the driving circuit can also be determined in advance as the frequency jittering period of the driving circuit. For each frequency jittering period, multiple first target driving frequencies of the driving circuit within the frequency jittering period are determined according to the original driving frequency. For example, the original driving frequency of the PWM signal is 20kHz. Taking 4 frequency jittering periods as an example, when the frequency jittering period is 20s, a target driving frequency corresponds to every 5s interval, that is, 4 target driving frequencies can be randomly determined for one frequency jittering period, such as 18kHz, 19kHz, 21kHz, and 18kHz, respectively.

[0054] Step 103: Control the driving circuit to drive based on at least one first target driving frequency.

[0055] For the embodiment of the present disclosure, as a possible implementation method, if the number of the first target driving frequency is 1, that is, the first target driving frequency is the first target driving frequency corresponding to the current driving, and the target driving frequency corresponding to the current driving needs to be determined before each driving, then after determining that the original driving frequency corresponds to the first target driving frequency of the current driving, the driving circuit can be controlled to perform the current driving according to the first target driving frequency; for example, if it is determined that the first target driving frequency corresponding to this driving is 18kHz, and the time interval between each driving is 5s, then within the 5s time interval corresponding to this driving, the driving circuit is controlled to drive at 18kHz.

[0056] As another possible implementation, if the number of the first target drive frequencies is multiple, that is, the multiple first target drive frequencies are multiple first target drive frequencies within the frequency jittering cycle, then after determining the multiple first target drive frequencies within the frequency jittering cycle, the drive circuit can be controlled to perform periodic driving in sequence according to the multiple first target drive frequencies within the frequency jittering cycle. For example, the four first target drive frequencies determined within the frequency jittering cycle are 18kHz, 19kHz, 21kHz, and 18kHz, respectively. Then, when the drive circuit can be controlled to perform periodic frequency jittering processing according to the four first target drive frequencies in sequence within the frequency jittering cycle, in the first interval of 5s in the frequency jittering cycle, the drive circuit is controlled to drive at 18kHz, in the second interval of 5s, the drive circuit is controlled to drive at 19kHz, in the third interval of 5s, the drive circuit is controlled to drive at 21kHz, and in the last interval of 5s, the drive circuit is controlled to drive at 18kHz. By setting the frequency jittering period of the driving circuit and performing periodic frequency jittering according to multiple first target driving frequencies within the frequency jittering period, repetitive determination of the first target driving frequency can be avoided, thereby reducing the calculation workload and improving the processing efficiency of the frequency jittering.

[0057] It should be noted that if the driving frequency corresponding to each drive needs to be determined before each drive, after completing the current drive, in the subsequent driving process, the second target driving frequency corresponding to the original driving frequency can be determined for the next drive. The second target driving frequency is different from the original driving frequency, and the second target driving frequency is any driving frequency within the preset driving range; the driving circuit is further controlled to perform the next drive according to the second target driving frequency.

[0058] For example, if it is determined that the first target driving frequency corresponding to the current driving of the original driving frequency is 19kHz, the driving circuit can be controlled to perform the current driving at 19kHz; after completing the current driving, the second target driving frequency corresponding to the original driving frequency for the next driving can be determined, such as 18kHz, and then the next driving can be performed based on the second target driving frequency.

[0059] In summary, according to the electromagnetic interference suppression method of the PWM signal provided by the embodiment of the present disclosure, after obtaining the PWM signal generated by the driving circuit and the original driving frequency of the PWM signal, the original driving frequency can be processed to determine at least one first target driving frequency for reducing the electromagnetic interference generated by the original driving frequency, and then based on the at least one first target driving frequency, the driving circuit is controlled to drive. The technical solution in the present disclosure can randomly adjust the original driving frequency of the PWM signal within the allowed range through driving frequency processing, thereby changing the frequency point of the high-order harmonics corresponding to the PWM signal, so that the frequency point of the high-order harmonics is not fixed, and electromagnetic interference cannot be generated at a fixed frequency point, thereby effectively suppressing the electromagnetic interference of the PWM signal and reducing the harmfulness of EMI radiation interference.

[0060] Further, as a refinement and extension of the above embodiment, in order to fully illustrate the specific implementation process of the method of this embodiment, this embodiment provides the following Figure 4 The specific method shown includes:

[0061] Step 201: Acquire a PWM signal generated by a driving circuit.

[0062] For the embodiment of the present disclosure, the specific implementation process can refer to the relevant description in step 101 of the embodiment, which will not be repeated here.

[0063] Step 202: Adjust the conversion time of the PWM signal corresponding to the high and low level conversion, adjust the PWM signal from a square wave signal to a sine wave signal, and update the sine wave signal to a PWM signal.

[0064] The PWM signal generated by the driving circuit is a square wave signal. As the PWM signal is closer to an ideal square wave, it has more frequency components, which means more noise components and worse EMI. The noise components may be high-order harmonic components. If you want to reduce the noise spectrum components, you need to change the waveform of the square wave. In the embodiment of the present disclosure, the square wave signal can be adjusted to a sine wave signal.

[0065] For the embodiments of the present disclosure, the PWM signal can be adjusted from a square wave signal to a sine wave signal by adjusting the conversion time corresponding to the low level to the high level and the conversion time corresponding to the high level to the low level of the PWM signal, thereby reducing the noise spectrum component and reducing the electromagnetic interference generated by the original driving frequency corresponding to the PWM signal. There are many ways to extend the conversion time from high level to low level and the conversion time from low level to high level, for example, the conversion time from high level to low level and the conversion time from low level to high level can be extended by configuring registers through software, or the conversion time from high level to low level and the conversion time from low level to high level can be extended by adjusting the filter capacitor. Exemplarily, after obtaining the PWM signal generated by the driving circuit, the PWM signal can be adjusted from a square wave signal to a sine wave signal by extending the conversion time from a high level to a low level and the conversion time from a low level to a high level of the PWM signal, so as to reduce the electromagnetic interference generated by the original driving frequency corresponding to the PWM signal. Thereafter, the original driving frequency of the sine wave signal is further processed by driving frequency to change the frequency of high-order harmonics, so that the frequency of high-order harmonics is not fixed and electromagnetic interference cannot be generated at a fixed frequency, thereby effectively suppressing the electromagnetic interference of the PWM signal.

[0066] Accordingly, for the embodiments of the present disclosure, in response to the driving circuit being an H-bridge driving circuit, when adjusting the conversion time corresponding to the high and low level conversion of the PWM signal, as a possible implementation method, the registers in the driving circuit can be configured and the rising edge and falling edge times can be directly set by using the registers to extend the conversion time corresponding to the high and low level conversion of the PWM signal; as a possible implementation method, the capacitance value of the filter capacitor in the H-bridge driving circuit can be adjusted, such as by using the current amplification effect of a MOS tube or a transistor to indirectly increase the capacitance of the filter capacitor, thereby extending the conversion time corresponding to the high and low level conversion of the PWM signal.

[0067] Among them, the filter capacitor in the H-bridge driving circuit may include: an RC filter circuit arranged at the gate position of each MOS tube or the base position of each transistor in the H-bridge driving circuit; or, an X capacitor arranged at the drain position of the corresponding MOS tube or the collector position of the corresponding transistor in the H-bridge driving circuit; or, a Y capacitor arranged at the source position of the corresponding MOS tube or the emitter position of the corresponding transistor in the H-bridge driving circuit.

[0068] Step 203: Determine the original driving frequency of the PWM signal.

[0069] The original driving frequency of the PWM signal is a fixed frequency under high-order harmonics. The following technical solution in the present disclosure aims to randomly adjust the original driving frequency of the PWM signal, thereby changing the frequency of the high-order harmonics, making the frequency of the high-order harmonics non-fixed, so that it has no way to generate electromagnetic interference at a fixed frequency.

[0070] Step 204: determine at least one first target driving frequency corresponding to the original driving frequency, where the first target driving frequency is different from the original driving frequency and is any driving frequency within a preset driving range.

[0071] For the embodiment of the present disclosure, since the process of determining each first target driving frequency in at least one first target driving frequency is similar, for ease of description, determining a first target driving frequency is taken as an example for description:

[0072] As a possible implementation method, the first jitter frequency can be randomly determined within the preset jitter frequency range, and the original drive frequency and the first jitter are added to obtain the first target drive frequency corresponding to the original drive frequency. Among them, the preset jitter frequency range is the maximum jitter frequency range that can drive the vehicle chip product to work stably and can suppress electromagnetic interference. For example, the original drive frequency of the PWM signal is F (Hz), and the preset jitter frequency range is set to ±2kHz. By adding the first target jitter frequency of F±2 (kHz) frequency to make it different from the original drive frequency, the frequency of the high-order harmonics is not fixed, which can reduce the continuous electromagnetic interference generated by the drive circuit at the F frequency.

[0073] Accordingly, after determining the first target driving frequency based on the above method, in order to ensure that the first target driving frequency can be within the preset driving range, the embodiment steps may also include: detecting whether the first target driving frequency exceeds the preset driving range; if it exceeds the preset driving range, re-determining the second jitter frequency, adding the original driving frequency and the re-determined second jitter frequency, and obtaining the first target driving frequency corresponding to the original driving frequency. The preset driving range is the maximum jitter frequency range that can drive the vehicle chip product to work stably and can suppress electromagnetic interference.

[0074] For example, the preset driving range is 18 to 21kHz, the original driving frequency of the PWM signal is 20kHz, and the preset jittering range is set to ±2Hz. If the first jittering frequency is randomly determined to be 2kHz within the preset jittering frequency range, the original driving frequency and the first jittering frequency are added to obtain a first candidate driving frequency corresponding to the original driving frequency of 22kHz. In view of the fact that the calculated first candidate driving frequency has exceeded the preset driving range, the second jittering frequency can be re-determined within the preset jittering frequency range, and the second jittering frequency is added to the original driving frequency to obtain a second candidate driving frequency. If the second candidate driving frequency is within the range of 18 to 21kHz, the second candidate driving frequency is determined as the first target driving frequency.

[0075] As another possible implementation method, a driving frequency randomly determined within a preset driving range can be determined as the first target driving frequency, wherein the second driving frequency is a driving frequency different from the original driving frequency. The preset driving range is the maximum driving frequency range that can drive the vehicle chip product to work stably and can suppress electromagnetic interference. For example, the preset driving range is 18 to 21kHz, and the original driving frequency of the PWM signal is 20kHz. When determining the first target jitter frequency, a driving frequency different from the original driving frequency can be directly randomly selected within 18 to 21kHz, such as 19kHz, and 19kHz can be determined as the first target driving frequency.

[0076] Step 205: Control the driving circuit to drive based on at least one first target driving frequency.

[0077] For the embodiment of the present disclosure, the embodiment steps may include: if the number of first target driving frequencies is one, then controlling the driving circuit to perform this driving according to the first target driving frequency; if the number of first target driving frequencies is multiple, then within a preset frequency jittering cycle, controlling the driving circuit to drive with the corresponding first target driving frequencies in sequence, wherein the number of times the driving is performed within the preset frequency jittering cycle is the same as the total number of the first target driving frequencies.

[0078] In a specific application scenario, if the number of first target driving frequencies is one, that is, before each driving of the driving circuit, it is necessary to determine the first target driving frequency corresponding to the current driving, then after completing the current driving based on the first target driving frequency corresponding to the current driving, in the subsequent driving process, the second target driving frequency corresponding to the original driving frequency can be determined for the next driving, the second target driving frequency is different from the original driving frequency, and the second target driving frequency is any driving frequency within the preset driving range; the driving circuit is further controlled to perform the next driving according to the second target driving frequency. For the determination process of the second target driving frequency, please refer to the relevant description of determining the first target driving frequency in step 204 of the embodiment, which will not be repeated here.

[0079] In summary, according to the electromagnetic interference suppression method of the PWM signal provided by the embodiment of the present disclosure, after obtaining the PWM signal generated by the driving circuit and the original driving frequency of the PWM signal, at least one first target driving frequency for reducing the electromagnetic interference generated by the original driving frequency can be determined, and then based on the at least one first target driving frequency, the driving circuit can be controlled to drive. The technical solution in the present disclosure can randomly adjust the original driving frequency of the PWM signal within the allowed range through driving frequency processing, thereby changing the frequency of the higher harmonics, so that the frequency of the higher harmonics is not fixed and electromagnetic interference cannot be generated at a fixed frequency. In addition, the PWM signal can be adjusted from a square wave signal to a sine wave signal by adjusting the conversion time corresponding to the high and low level conversions of the PWM signal, so as to reduce the electromagnetic interference generated by the PWM signal corresponding to the original driving frequency. By combining the two electromagnetic interference suppression methods, the electromagnetic interference of the PWM signal can be effectively suppressed, and the harmfulness of EMI radiation interference can be reduced.

[0080] Based on the above Figure 1 , Figure 4 The specific implementation of the method shown in the embodiment provides an electromagnetic interference suppression device for a PWM signal, such as Figure 5 As shown, the device includes: an acquisition module 31, a determination module 32, and a control module 33.

[0081] The acquisition module 31 can be used to acquire the PWM signal generated by the driving circuit and the original driving frequency of the PWM signal, where the original driving frequency is the high-order harmonic frequency corresponding to the PWM signal;

[0082] The determination module 32 may be used to determine at least one first target driving frequency corresponding to the original driving frequency, the first target driving frequency being different from the original driving frequency, the first target driving frequency being any driving frequency within a preset driving range, wherein at least one first target driving frequency is not completely the same;

[0083] The control module 33 can be used to control the driving circuit to drive based on at least one first target driving frequency.

[0084] In some embodiments of the present disclosure, the control module 33 can be used to control the driving circuit to perform the current driving according to the first target driving frequency if the number of the first target driving frequencies is one; if the number of the first target driving frequencies is multiple, then within a preset frequency jittering cycle, the control driving circuit is driven with the corresponding first target driving frequencies in sequence, wherein the number of times the driving is performed within the preset frequency jittering cycle is the same as the total number of the first target driving frequencies.

[0085] In some embodiments of the present disclosure, the determination module 32 can also be used to determine a second target driving frequency corresponding to the original driving frequency during the next driving, where the second target driving frequency is different from the original driving frequency and is any driving frequency within a preset driving range; the control module 33 can also be used to control the driving circuit to perform the next driving according to the second target driving frequency.

[0086] In some embodiments of the present disclosure, the PWM signal is a square wave signal, such as Figure 6 As shown, the device further includes: an adjustment module 34;

[0087] The adjustment module 34 can be used to adjust the conversion time of the PWM signal corresponding to the high and low level conversion, adjust the PWM signal from a square wave signal to a sine wave signal, and update the sine wave signal to a PWM signal.

[0088] In some embodiments of the present disclosure, in response to the driving circuit being an H-bridge driving circuit, the adjustment module 34 can be used to configure the registers in the driving circuit to extend the conversion time of the PWM signal corresponding to the high and low level conversion; or by adjusting the capacitance value of the filter capacitor in the H-bridge driving circuit to extend the conversion time of the PWM signal corresponding to the high and low level conversion.

[0089] In some embodiments of the present disclosure, the filter capacitor in the H-bridge drive circuit includes: an RC filter circuit arranged at the gate position of each MOS tube or the base position of each transistor in the H-bridge drive circuit; or an X capacitor arranged at the drain position of the corresponding MOS tube or the collector position of the corresponding transistor in the H-bridge drive circuit; or a Y capacitor arranged at the source position of the corresponding MOS tube or the emitter position of the corresponding transistor in the H-bridge drive circuit.

[0090] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0091] The various techniques described herein may be implemented in combination with hardware or software, or a combination thereof. Thus, the method and apparatus of the present invention, or some aspects or parts of the method and apparatus of the present invention may be in the form of program codes (i.e., instructions) embedded in a tangible medium, such as a removable hard disk, a USB flash drive, a floppy disk, a CD-ROM, or any other machine-readable storage medium, wherein when the program is loaded into a machine such as a computer and executed by the machine, the machine becomes a device for practicing the present invention.

[0092] In the case where the program code is executed on a programmable computer, the computing device generally includes a processor, a storage medium readable by the processor (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. The memory is configured to store the program code; the processor is configured to execute the method of the present invention according to the instructions in the program code stored in the memory.

[0093] By way of example and not limitation, readable media include readable storage media and communication media. Readable storage media stores information such as computer readable instructions, data structures, program modules or other data. Communication media generally embody computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and include any information transfer medium. Any combination of the above is also included within the scope of readable media.

[0094] In the description provided herein, algorithms and displays are not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the examples of the present invention. According to the above description, it is obvious that the structure required for constructing such systems. In addition, the present invention is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to implement the content of the present invention described herein, and the above description of specific languages ​​is for the purpose of disclosing the preferred embodiment of the present invention.

[0095] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and methods are not shown in detail.

[0096] structures and techniques so as not to obscure the understanding of this specification.

[0097] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim.

[0098] Those skilled in the art will appreciate that the modules or units or components of the devices in the examples disclosed herein may be arranged in the devices described in the embodiment, or alternatively may be located in one or more devices different from the devices in the examples. The modules in the foregoing examples may be combined into one module or may be divided into multiple submodules.

[0099] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition they may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0100] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is meant to be within the scope of the present invention and to form different embodiments.

[0101] In addition, some of the embodiments are described herein as a combination of methods or method elements that can be implemented by a processor of a computer system or by other devices that perform functions. Therefore, a processor with necessary instructions for implementing a method or method element forms a device for implementing the method or method element. In addition, the elements of the device embodiment herein are examples of devices that are used to implement the functions performed by the elements for the purpose of implementing the invention.

[0102] As used herein, unless otherwise specified, the use of ordinal numbers "first," "second," "third," etc. to describe common objects merely indicates that different instances of similar objects are involved, and is not intended to imply that the objects so described must have a given order in time, space, order, or in any other manner.

[0103] Although the present invention has been described according to a limited number of embodiments, it will be understood by those skilled in the art, with the benefit of the above description, that other embodiments may be envisioned within the scope of the invention thus described. In addition, it should be noted that the language used in this specification is selected primarily for readability and teaching purposes, rather than for explaining or limiting the subject matter of the present invention. Therefore, many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the appended claims. With respect to the scope of the present invention, the disclosure of the present invention is illustrative rather than restrictive, and the scope of the present invention is defined by the appended claims. It should be understood that various forms of processes shown above may be used to reorder, add or delete steps. For example, the steps described in this disclosure may be performed in parallel, sequentially, or in different orders, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved, and this document is not limited thereto.

[0104] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for suppressing electromagnetic interference of a PWM signal, characterized in that: include: Acquire a PWM signal generated by a driving circuit, and determine an original driving frequency of the PWM signal, wherein the original driving frequency is a higher harmonic frequency corresponding to the PWM signal; Determine at least one first target driving frequency corresponding to the original driving frequency, the first target driving frequency is different from the original driving frequency, the first target driving frequency is any driving frequency within a preset driving range, wherein the at least one first target driving frequency is not completely the same; Based on the at least one first target driving frequency, the driving circuit is controlled to drive.

2. The method according to claim 1, characterized in that The step of controlling the driving circuit to drive based on the at least one first target driving frequency includes: If the number of the first target driving frequency is one, controlling the driving circuit to perform the current driving according to the first target driving frequency; If there are multiple first target driving frequencies, the driving circuit is controlled to drive with the corresponding first target driving frequencies in sequence within a preset frequency jittering period, wherein the number of driving times within the preset frequency jittering period is the same as the total number of first target driving frequencies.

3. The method according to claim 2, characterized in that After controlling the driving circuit to drive based on the at least one first target driving frequency, the method further includes: Determine a second target driving frequency corresponding to the original driving frequency during the next driving, the second target driving frequency is different from the original driving frequency, and the second target driving frequency is any driving frequency within a preset driving range; The driving circuit is controlled to perform next driving according to the second target driving frequency.

4. The method according to claim 1, characterized in that: The PWM signal is a square wave signal. After acquiring the PWM signal generated by the driving circuit and before determining the original driving frequency of the PWM signal, the method further includes: The conversion time length of the PWM signal corresponding to the high and low level conversion is adjusted, the PWM signal is adjusted from a square wave signal to a sine wave signal, and the sine wave signal is updated to the PWM signal.

5. The method according to claim 4, characterized in that In response to the driving circuit being an H-bridge driving circuit, the adjusting the conversion time of the PWM signal corresponding to the high and low level conversions includes: Configuring registers in the driving circuit to extend the conversion time of the PWM signal corresponding to high and low level conversions; or By adjusting the capacitance value of the filter capacitor in the H-bridge driving circuit, the conversion time of the PWM signal corresponding to the high and low level conversion is prolonged.

6. The method according to claim 5, characterized in that The filter capacitor in the H-bridge driving circuit includes: An RC filter circuit is provided at the gate position of each MOS tube or the base position of each triode in the H-bridge driving circuit; or An X capacitor is arranged at the drain position of the MOS tube or the collector position of the transistor corresponding to the H-bridge driving circuit; or A Y capacitor is arranged at the source position of the MOS tube or the emitter position of the transistor in the H-bridge driving circuit.

7. A PWM signal electromagnetic interference suppression device, characterized in that: include: An acquisition module, used for acquiring a PWM signal generated by a driving circuit, and determining an original driving frequency of the PWM signal, wherein the original driving frequency is a higher harmonic frequency corresponding to the PWM signal; a determination module, configured to determine at least one first target driving frequency corresponding to the original driving frequency, wherein the first target driving frequency is different from the original driving frequency, and the first target driving frequency is any driving frequency within a preset driving range, wherein the at least one first target driving frequency is not completely the same; The control module is used to control the driving circuit to drive based on the at least one first target driving frequency.

8. An electronic device comprising: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium storing computer instructions, wherein: The computer instructions are used to cause the computer to execute the method according to any one of claims 1-6.

10. A vehicle, characterized in that: include: The electronic device as claimed in claim 8.

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