Method and apparatus for suppressing electromagnetic interference of power supply

Abstract

This application relates to a method and related apparatus for suppressing electromagnetic interference (EMI) in a power supply. The EMI suppression method includes: detecting the rate of change of electrical parameters of the power supply; determining the degree of spread corresponding to the rate of change of the electrical parameters based on a mapping relationship between the rate of change of the electrical parameters and the degree of spread; and performing spread spectrum processing on the power supply based on the degree of spread. This application can improve the EMI suppression effect.

Description

Technical Field

[0001] This application relates to the field of electromagnetic interference suppression technology, and in particular to electromagnetic interference suppression methods and apparatus for power supplies. Background Technology

[0002] With the development of power supply platforms towards higher power and higher frequencies, as well as the miniaturization of power supplies, there are smaller requirements for high-frequency power supplies and components, making them more suitable for portable devices. Simultaneously, the widespread adoption of wide-bandgap semiconductors has increased the limits of high-frequency operation. SiC and GaN devices support MHz-level switching frequencies, reducing losses by more than 50% and achieving efficiencies of up to 98%. High-frequency power supplies refer to power electronic conversion devices with operating frequencies significantly higher than traditional power frequencies, typically operating in the range of tens of kHz to MHz. Due to their high efficiency, stability, and flexibility, high-frequency power supplies are widely used in various fields such as security and power.

[0003] EMI issues in high-frequency power supplies are one of the core challenges in their design, primarily caused by high-frequency noise and parasitic parameters resulting from high-frequency switching operations. However, current power supply electromagnetic interference suppression methods are inadequate. Summary of the Invention

[0004] This application discloses a method and apparatus for suppressing electromagnetic interference in a power source, in order to improve the suppression effect of electromagnetic interference.

[0005] To achieve the above objectives, this application provides a method for suppressing electromagnetic interference (EMI) in a power supply, the method comprising: Detect the rate of change of the electrical parameters of the power supply; Based on the mapping relationship between the rate of change of the electrical parameters and the degree of expansion, the degree of expansion corresponding to the rate of change of the electrical parameters is determined; The spectrum of the power supply is spread based on the degree of spread.

[0006] To address the aforementioned problems, this application provides an electromagnetic interference suppression device for a power supply, the device comprising: The detection unit is used to detect the rate of change of the electrical parameters of the power supply. A spread spectrum parameter setting unit is used to determine the spread degree corresponding to the rate of change of the electrical parameters based on the mapping relationship between the rate of change of the electrical parameters and the spread degree, and to set the spread spectrum parameters based on the spread degree; and, The spreading unit is used to spread the power spectrum based on spreading parameters.

[0007] The method of this application is as follows: The rate of change of the electrical parameters of the power supply is detected; based on the mapping relationship between the rate of change of the electrical parameters and the degree of spread, the degree of spread corresponding to the rate of change of the electrical parameters is determined; then, the spectrum of the power supply is spread based on the degree of spread. This spread-spectrum processing reduces the electromagnetic interference of the power supply. Furthermore, by establishing a relationship between the rate of change of electrical parameters such as the voltage change rate dv / dt and the current change rate di / dt and the degree of spread of the spectrum, different degrees of spread are used to optimize the spectrum for different rates of change of electrical parameters, thereby improving the optimization effect of the spectrum energy and thus improving the suppression effect of electromagnetic interference. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings that can be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a flowchart illustrating one implementation method of the electromagnetic interference suppression method for the power supply in this application. Figure 2 This is a schematic diagram of the spread spectrum structure in the electromagnetic interference suppression method for the power supply of this application; Figure 3 This is a schematic diagram of the structure of an implementation method of the electromagnetic interference suppression method device for the power supply of this application; Figure 4 This is a schematic diagram of the structure of one embodiment of the electronic device of this application; Figure 5 This is a schematic diagram of one embodiment of the computer storage medium of this application. Detailed Implementation

[0010] To enable those skilled in the art to better understand the technical solutions of this application, the device protocol identification method and related apparatus provided in this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0011] The terms "first," "second," and "third" used in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0012] In this document, the term "implementation" means that a specific feature, structure, or characteristic described in connection with an implementation may be included in at least one implementation of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same implementation, nor is it a separate or alternative implementation mutually exclusive with other implementations. It will be explicitly and implicitly understood by those skilled in the art that, without conflict, the implementations described herein may be combined with other implementations.

[0013] like Figure 1 As shown, the electromagnetic interference suppression method for a power supply according to one embodiment of this application specifically includes the following steps. It should be noted that the step numbers are for simplification only and are not intended to limit the execution order of the steps. The execution order of each step in this embodiment can be arbitrarily changed without departing from the technical concept of this application.

[0014] S11: Detects the rate of change of electrical parameters of the power supply.

[0015] The high rate of change of electrical parameters is the main cause of electromagnetic interference. This application can detect the rate of change of electrical parameters of the power supply, and then spread the spectrum of the power supply based on the rate of change of electrical parameters. In this way, electromagnetic interference problems can be adaptively handled based on the factors that cause electromagnetic interference, thereby improving electromagnetic interference suppression efficiency.

[0016] The rates of change of electrical parameters can include the rate of change of voltage dv / dt and / or the rate of change of current di / dt.

[0017] In one implementation, the rate of change of electrical parameters of the power supply can be detected using envelope detection. In one example, envelope detection can be used to detect the ripple of the power supply output, thereby enabling the detection of the power supply's dv / dt and di / dt.

[0018] Optionally, the rate of change of electrical parameters of the power supply can be detected by an envelope detector composed of diodes, capacitors and resistors.

[0019] In another embodiment, the rate of change of the electrical parameters of the power supply can be detected using an oscilloscope, voltage probe, or current probe.

[0020] In a specific example, an oscilloscope can be used to capture the instantaneous waveforms of voltage and / or current, and then their slopes can be calculated to obtain the rate of change of voltage dv / dt and / or the rate of change of current di / dt of the power supply.

[0021] In another specific example, the voltage change rate of the power supply can be obtained by measuring rapidly changing signals with high common-mode voltage to ground, such as those at switching nodes (e.g., between the drain and source of a MOSFET), using a differential voltage probe.

[0022] In another specific example, a current probe can be used to convert a current signal into a voltage signal for measurement by an oscilloscope to calculate di / dt.

[0023] S12: Based on the mapping relationship between the rate of change of electrical parameters and the degree of expansion, determine the degree of expansion corresponding to the rate of change of electrical parameters.

[0024] After detecting the rate of change of the electrical parameters of the power supply, the degree of spread corresponding to the rate of change of the electrical parameters can be determined based on the mapping relationship between the rate of change of the electrical parameters and the spread degree. This allows for subsequent spread spectrum processing of the power supply based on the spread degree Δf. By establishing a relationship between the rate of change of electrical parameters such as dv / dt and di / dt and the spread degree Δf of the spectrum, different spread degrees Δf can be used to optimize the spectrum for different rates of change of electrical parameters such as dv / dt and di / dt, thereby improving the optimization effect of spectrum energy.

[0025] The spread factor, corresponding to the rate of change of electrical parameters, can be used to represent the degree of difference between the spread spectrum bandwidth and the original spectrum bandwidth. In specific examples, the spread factor can be used to represent the ratio or difference between the spread spectrum bandwidth and the original spectrum bandwidth.

[0026] In one implementation, the electromagnetic interference suppression rate of each degree of expansion can be tested at various rates of change of electrical parameters. Based on the test results, the optimal degree of expansion at each rate of change of electrical parameters can be determined, and the mapping relationship between the rate of change of electrical parameters and the optimal degree of expansion can be recorded. Thus, step S12 can determine the degree of expansion corresponding to the rate of change of electrical parameters based on the mapping relationship between the rate of change of electrical parameters and the degree of expansion.

[0027] Furthermore, the spread degree Δf values ​​under different rates of change of electrical parameters (e.g., dv / dt and di / dt values) can be collected. Machine learning can be introduced to train the mapping relationship between dv / dt, di / dt, and the optimal Δf, enabling real-time prediction of dynamic spectrum spread and adapting to spectrum changes under different load conditions. The process of establishing this mapping relationship includes: real-time detection of the rate of change of electrical parameters such as dv / dt and di / dt of the high-frequency power supply; spreading the power supply spectrum into spectra with different spread degrees; recording the electromagnetic interference suppression rate of the corresponding Δf values ​​under different rates of change of electrical parameters such as dv / dt and / or di / dt; and based on the recorded data, using machine learning algorithms (such as neural networks, regression analysis, etc.) to establish a mapping model between the rate of change of each electrical parameter such as dv / dt and / or di / dt and Δf. In actual operation, the optimal Δf value is predicted using the trained machine learning model based on the detected real-time dv / dt and di / dt values. Thus, the spread degree corresponding to the rate of change of electrical parameters can be determined based on the mapping relationship between the rate of change of electrical parameters and the spread degree.

[0028] Through steps S12 and S13, when the values ​​of dv / dt and di / dt are large, Δf needs to be larger, so the spectrum extension range is also larger, and the energy of the generated EMI noise in this frequency band will be averaged, thereby achieving spectrum energy optimization for special frequency bands.

[0029] S13: Spread the spectrum of the power supply based on the degree of spread.

[0030] After determining the degree of spread corresponding to the rate of change of electrical parameters, the spectrum of the power supply can be spread based on the degree of spread Δf.

[0031] The core idea of ​​spread spectrum technology is to distribute energy originally concentrated on a single frequency across a wider bandwidth by periodically fine-tuning the switching frequency. This is like turning a bright "lighthouse" into a soft "twilight." Although the total energy remains the same, the energy peak at any single frequency point is significantly reduced. In this way, electromagnetic interference of the power supply is reduced through spread spectrum processing. Furthermore, by establishing a relationship between the rate of change of electrical parameters such as dv / dt and di / dt of the power supply and the wideband Δf of the spectrum, different Δf values ​​are used to optimize the frequency for different rates of change of electrical parameters such as dv / dt and di / dt, thereby improving the optimization effect of spectrum energy.

[0032] In one implementation, the spectrum of the power supply can be spread based on the spread degree to expand the spread spectrum bandwidth to the spread degree.

[0033] In another implementation, the bandwidth of the power supply's spectrum can be broadened to the extent that the spread spectrum bandwidth is the sum of the original bandwidth of the power supply's spectrum and the extent of the broadening.

[0034] A power spread spectrum system can be integrated into the power controller. This system can be integrated into the oscillator and PWM generator circuits of the power controller chip to "spread" noise energy by changing the basic switching rhythm before electromagnetic noise is generated, thereby spreading the spectrum of the power supply.

[0035] like Figure 2 As shown, a power supply spread spectrum system may include a reference oscillator, a spread spectrum modulation module, a controlled oscillator, a PWM controller, and a driver.

[0036] A reference oscillator is used to provide a stable and accurate fixed-frequency clock source, serving as the "time reference" for the entire frequency modulation system. It can be a crystal oscillator or an RC oscillator circuit. The reference oscillator can be integrated within the power controller IC. The reference oscillator determines the initial accuracy of the spread spectrum center frequency.

[0037] The spread spectrum modulation module is the "brain" of spread spectrum technology, responsible for generating the modulation pattern. It typically includes the following sub-parts: a modulation waveform generator, a modulation depth / range controller, and / or a modulation rate controller.

[0038] A modulation waveform generator is used to generate specific modulation waveforms, such as triangular waves, sawtooth waves, or pseudo-random sequences, which determines the type of spread spectrum (center spread spectrum, fall spread spectrum, etc.). The modulation waveform generator can be an analog circuit (such as an integrator composed of operational amplifiers or a function generator) or a digital circuit (such as a DDS direct digital frequency synthesizer or an LFSR linear feedback shift register used to generate pseudo-random codes).

[0039] A modulation depth / range controller can be used to set the amplitude (Δf) of the frequency variation. For example, with a center frequency of 500 kHz and a modulation depth of ±5%, the frequency variation range is 475 kHz to 525 kHz. This is typically set via a dedicated pin connected to an external resistor or configuration register. In this application, after determining the spread factor in step S12, the modulation depth and frequency variation range can be set based on the spread factor. The width of the frequency variation range can be changed to the spread factor, or the sum of the spread factor and the original bandwidth of the power supply's spectrum. In one embodiment, the configuration register or the resistance value of the external resistor can be set based on the spread factor to set the modulation depth and frequency variation range, among other spread spectrum parameters.

[0040] A modulation rate controller is used to set the frequency of the modulation waveform (such as a triangular wave). This frequency is typically low (100Hz-1kHz) and determines how quickly the switching frequency changes. The modulation speed is usually configured via an external capacitor (which sets the frequency of the internal oscillator) or a resistor.

[0041] A controlled oscillator (SOS) is the "actuator" in spread spectrum technology, changing the switching frequency in real time according to the instructions of the modulation module. The SOS primarily receives voltage or digital signals from the modulation module and outputs a clock signal with a corresponding frequency. The main types of SOS are: voltage-controlled oscillators (VCOs), where the analog voltage (such as a triangular wave) output by the modulation module directly controls the VCO's output frequency; or digitally programmable oscillators (DPOs), where the digital code output by the modulation module directly controls the oscillator's division ratio or initial count value, thereby precisely and discretely changing the output frequency.

[0042] The spread spectrum system described above may also include external configuration elements and / or power stages and feedback circuits.

[0043] External configuration components are external parts that "tell" the chip how to work and are key to achieving flexible design.

[0044] External configuration elements may include resistors (R_SSFM) or registers for setting the center frequency and / or modulation depth. Optionally, the configuration register or the value of the external resistor may be set based on the extension level to set the modulation depth and frequency variation range, etc.

[0045] External configuration components may also include components such as capacitors (C_SSFM) for setting the modulation rate.

[0046] External configuration elements may also include an enable / select pin, which may be a digital pin used to enable / disable the spread spectrum function or to select between different modulation modes (such as triangular wave, pseudo-random).

[0047] The power stage and feedback loop (the objects of spread spectrum) are not part of the spread spectrum structure themselves, but they are the final carriers of the spread spectrum signal.

[0048] The power stage and feedback loop can include PWM logic and drivers, power MOSFETs, inductors, capacitors, diodes, and feedback compensation loops.

[0049] PWM logic and drivers are used to receive a clock signal with a constantly changing frequency from a controlled oscillator and generate a PWM wave of the corresponding frequency to drive the power MOSFETs in the subsequent stage.

[0050] Components such as power MOSFETs, inductors, capacitors, and diodes operate at varying switching frequencies, which "broadens" the spectrum of their switching noise, thereby reducing EMI peaks at specific frequencies.

[0051] When frequency jitter is introduced, the power supply's feedback compensation loop must have sufficient phase margin to ensure that the system remains stable throughout the entire frequency variation range.

[0052] Of course, the power supply spectrum can also be spread using other spread spectrum structures or methods.

[0053] In one example, the spectrum of the power supply can be spread by modulating the position / edge of the switching pulse.

[0054] The position / edge of the modulation switch pulse does not change the switching frequency (i.e., the switching period T_sw is constant), but the spectrum is scattered by modulating the phase or duty cycle of each switch pulse.

[0055] The spread spectrum structure for modulating the position / edge of the switching pulse can include a fixed frequency clock generator, a pulse modulation module, a jitter signal generator, and an adjustable delay line, etc.

[0056] A fixed-frequency clock generator replaces the VCO, providing a stable periodic signal.

[0057] The pulse modulation module is the core component. It receives a fixed clock signal but adds a tiny time-shift jitter to the rising edge, falling edge, or both of the generated PWM pulse.

[0058] A jitter signal generator produces a low-frequency modulation signal (such as a triangular wave or a pseudo-random sequence) to control the time shift of the pulse.

[0059] An adjustable delay line is a circuit that is controlled by a jitter signal and can precisely delay the pulse edge.

[0060] In modulation switching pulse position / edge, within a fixed switching cycle, the pulse's on-time (rising edge) and off-time (falling edge) are no longer fixed, but fluctuate back and forth with a very small amplitude (e.g., ±5% of the cycle). Although the average frequency remains unchanged, the specific waveform of each switching cycle is slightly different, which also disrupts the periodicity of the signal, thereby broadening the spectrum.

[0061] In another example, the spectrum of the power supply can be spread using a multiphase interleaving + spread spectrum method.

[0062] The multiphase interleaving + spread spectrum method is a system-level spread spectrum structure.

[0063] The spread spectrum structure of the multiphase interleaving + spread spectrum method can include N identical power stages, a spread spectrum clock generator, and an N-phase clock phase splitter / phase shifter, etc.

[0064] Each power stage has its own inductor and MOSFET.

[0065] The spread spectrum clock generator can be shared, and its main purpose is to generate a frequency-modulated master clock.

[0066] The N-phase clock phase splitter / phase shifter is used to receive the master clock and generate N drive signals with the same frequency but with phases delayed by 360° / N, which drive the N power stages respectively.

[0067] Without spread spectrum, if a 4-phase power supply operates at a fixed frequency of 1MHz with a 90° phase difference, the resulting input current ripple frequency will become 4MHz, but the energy will still be concentrated at 4MHz and its harmonics. In scenarios using multiphase interleaving + spread spectrum, after adding spread spectrum, if the master clock is frequency-modulated (e.g., varying between 900kHz and 1.1MHz), the switching frequencies of these four interleaved channels will change synchronously within this range. As a result, the noise spectrum of each channel is broadened, and the total noise spectrum resulting from their superposition becomes flatter, like a "mixed" noise floor.

[0068] In this implementation, the rate of change of the electrical parameters of the power supply is detected. Based on the mapping relationship between the rate of change of the electrical parameters and the degree of spread, the degree of spread corresponding to the rate of change of the electrical parameters is determined. Then, the spectrum of the power supply is spread based on the degree of spread Δf. In this way, the electromagnetic interference of the power supply is reduced by spreading. Furthermore, by establishing a relationship between the rate of change of electrical parameters such as dv / dt and di / dt and the broadband Δf of the spectrum, different Δf is used to optimize the frequency for different rates of change of electrical parameters such as dv / dt and di / dt, thereby improving the optimization effect of spectrum energy.

[0069] Optionally, the above-mentioned electromagnetic interference suppression method for power supply may further include filtering the power supply.

[0070] like Figure 3 As shown, the input power supply can be filtered by an EMI filter, and then the filtered power signal can be spread by a spread spectrum structure consisting of a power stage MOSFET, inductor, capacitor, diode and spread spectrum clock generator. Finally, the spread spectrum power signal can be filtered again by an output filter.

[0071] Among them, the filter located at the power input terminal (such as...) Figure 3 (e.g., the EMI filter shown) and / or filters located after the power stage (such as...) Figure 3 The output filter shown can filter the input power signal through multi-segment filtering to achieve power supply noise optimization.

[0072] Specifically, by setting n different filter cutoff frequencies in the power supply filter, multiple bands in the power supply spectrum can be filtered. In this way, efficient power supply filtering can be achieved by dynamically adjusting the power supply's filter cutoff frequency.

[0073] Optionally, n different filter cutoff frequencies can be set in the power supply filtering process through digital control, and the filter frequency band can be adjusted by logic control to achieve power supply filtering control.

[0074] Before filtering, the fundamental frequency of the power supply is detected to determine the frequency band that needs to be filtered, and the filter cutoff frequency is set according to the frequency band to be filtered.

[0075] One approach is to detect the fundamental frequency of the power supply, identify the high electromagnetic interference (EMI) frequency band (i.e., the high EMI spectrum energy region) in the power supply's spectrum, and then identify the high EMI frequency band as the frequency band that needs to be filtered.

[0076] After determining the filter cutoff frequency, the inductive impedance value in the filter circuit can be adjusted based on the filter cutoff frequency so that the filter circuit with adjusted inductive impedance can perform multi-band filtering of the power signal based on the filter cutoff frequency.

[0077] The impedance in the circuit described above uses adjustable impedance matching between key filter units, and the impedance matching is related to the filter cutoff frequency fm.

[0078] To achieve better multi-band filtering, multiple filters and suppression strategies can be designed and deployed for noise of different frequencies and types in the power supply noise spectrum, forming a complete filtering system to achieve multi-band filtering.

[0079] Alternatively, a power supply multi-band filtering system can be deployed in the order of "common mode first, then differential mode, low frequency first, then high frequency" and in the position of "input-internal-output".

[0080] In one example, the power signal is filtered across four frequency bands.

[0081] The first frequency band can be low-frequency differential-mode noise (<1MHz), which can originate from the fundamental frequency and its lower harmonics of the switching frequency, and / or the power frequency ripple after rectification. Filtering the first frequency band can provide energy buffering, smooth low-frequency pulsating current, and maintain voltage stability.

[0082] The filtering method for the first frequency band can use large-capacity aluminum electrolytic capacitors / polymer capacitors, which can be placed after the input rectifier bridge of the power supply and at the output of the power stage. Their high capacitance characteristics result in very low impedance at low frequencies. Alternatively, X capacitors can be used for filtering the first frequency band, positioned at the input of the EMI filter and connected between the live wire (L) and the neutral wire (N). Another option is an LC filter, which can be placed at the output of the power stage (the output filter in the diagram); the structure of an LC filter can be a power inductor + output capacitor.

[0083] The second frequency band can be mid-to-high frequency common-mode noise (1MHz ~ 30MHz). For the second frequency band, a common-mode inductor can be used. This inductor can be placed at the core of the EMI filter. It presents high impedance to common-mode current and almost zero impedance to differential-mode current (useful supply current), making it the most effective component for suppressing conducted common-mode EMI. Alternatively, a Y-capacitor can be used. Connected between L-GND and N-GND, it is typically placed after the common-mode inductor. It provides a low-impedance discharge path for common-mode noise, returning it to its source instead of flowing into the power grid. The capacitance value of the Y-capacitor is strictly limited to prevent excessive leakage current from causing electric shock.

[0084] The third frequency band can be high-frequency differential mode noise and ringing (10MHz ~ 100MHz). The filtering method for the third frequency band can employ high-frequency ceramic capacitors (MLCCs), which can be placed close to the pins of power switches (MOSFETs and diodes). MLCCs have extremely low ESL (Equivalent Series Inductance) and ESR, providing very high-frequency decoupling and energy compensation, effectively suppressing high-frequency voltage spikes and ringing caused by line inductance. Alternatively, the filtering method for the third frequency band can employ a Snubber circuit, which can be directly connected in parallel with the switch or diode. The Snubber circuit can be an RC series circuit, which absorbs ringing energy and converts it into heat, thereby damping the oscillation. The values ​​of R and C can be carefully designed according to the ringing frequency.

[0085] The fourth frequency band can be used for ultra-high frequency noise and radiated EMI (>100MHz). For filtering in the fourth frequency band, ferrite beads can be used. These beads can be connected in series with power or signal lines, typically located at the board interface. Ferrite beads have very low impedance at low frequencies, but exhibit high impedance at high frequencies (above tens of MHz), acting like a high-frequency choke that converts high-frequency noise into heat. It is one of the defenses against radiated EMI.

[0086] Furthermore, after the initial harmonics of the input power signal are processed, EMI noise interference on the multiple harmonic components generated by the high rate of change of the electrical parameters of the power supply can also be filtered.

[0087] To reduce EMI noise interference from other harmonic components, different adjustable filter circuits are connected in series after the primary harmonic. Each stage of the filter circuit is related to the higher harmonic spectrum of the high-frequency noise generated by dv / dt and di / dt. In other words, a corresponding filter circuit can be designed based on the higher harmonic spectrum characteristics generated by different dv / dt and di / dt values. Thus, the rate of change of electrical parameters such as dv / dt and di / dt of the power supply can also be detected beforehand.

[0088] The above design enables multi-segment filtering, which can dynamically adjust the filtering parameters according to the changes in the dv / dt and di / dt values ​​of the power supply to adapt to the spectrum changes under different load conditions. It can also perform targeted filtering for noise in different frequency ranges, rather than filtering a single frequency, and can simultaneously suppress EMI noise in the space and on the line.

[0089] The power supply electromagnetic interference suppression method of this application addresses the EMI noise problem of high-frequency power supplies by dynamically adjusting the power supply's frequency spectrum, sampling the EMI spectrum characteristics, and dynamically adjusting the parameters of the filter circuit to achieve EMI filtering design. Simultaneously, it suppresses the power supply's spectrum at the source, optimizing the spectrum for high EMI spectrum energy regions such as the fundamental frequency, increasing the spectral bandwidth to distribute energy evenly, and effectively suppressing the amplitude of high-frequency power supply EMI noise by identifying the correlation between load current and spectrum extension. Furthermore, through source filtering and line filtering design, it can suppress different high-frequency power supply noises, reducing the high-frequency noise space of the power supply and EMI noise on the lines. This also achieves cost reduction and miniaturization of the filtering scheme, ensuring stable and reliable system operation.

[0090] Furthermore, by optimizing the filtering scheme, the filtering cost and size design can be reduced, enabling miniaturized power supply EMI suppression design.

[0091] In one embodiment of the power supply electromagnetic interference suppression method of this application, such as Figure 3 As shown, tests revealed that the power supply electromagnetic interference suppression method of this application can effectively suppress power supply noise in the range of 150kHz-5MHz, and the filtering is adjustable.

[0092] This application also provides a power supply electromagnetic interference suppression device, which may include a detection unit, a spread spectrum parameter setting unit, and a spread spectrum unit.

[0093] The detection unit is used to detect the rate of change of the electrical parameters of the power supply. As shown above, the detection unit can be an oscilloscope, envelope detector, differential voltage probe, or current probe, etc.

[0094] The spread spectrum parameter setting unit can be used to determine the spread degree corresponding to the rate of change of the electrical parameters based on the mapping relationship between the rate of change of the electrical parameters and the spread degree, and set the spread spectrum parameters based on the spread degree. As shown above, spread spectrum parameters such as register parameters or resistor values ​​can be set based on the spread degree, and the spread spectrum unit can then perform spread spectrum processing on the power supply spectrum based on these parameters. Since the register parameters or resistor values ​​are related to the spread degree, the spread spectrum unit can perform spread spectrum processing on the power supply spectrum based on the spread degree.

[0095] A spreading unit can be used to spread the power spectrum based on spreading parameters. The spreading unit can be the spreading structure described above.

[0096] Optionally, the power supply electromagnetic interference suppression circuit may also include an input filter disposed before the spread spectrum unit, which can be used to perform multi-segment filtering of the power supply frequency.

[0097] The input filter can be used to process the first harmonic of the input power signal, and also to filter EMI noise interference on the multiple harmonic components generated by the high rate of change of the power supply's electrical parameters. To reduce EMI noise interference from other multiple harmonic components, different adjustable filter circuits are connected in series after the first harmonic. Each stage of the filter circuit is related to the higher harmonic spectrum of the high-frequency noise generated by dv / dt and di / dt.

[0098] Please see Figure 4 , Figure 4 This is a schematic diagram of one embodiment of the electronic device of this application. The electronic device 10 includes a processor 12, which executes instructions to implement the device protocol identification method described above. For detailed implementation processes, please refer to the description of the above embodiment; further details will not be repeated here.

[0099] Processor 12 can also be referred to as a CPU (Central Processing Unit). Processor 12 may be an integrated circuit chip with signal processing capabilities. Processor 12 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor may be a microprocessor, or processor 12 may be any conventional processor.

[0100] The electronic device 10 may further include a memory 11 for storing instructions and data required for the processor 12 to run.

[0101] The processor 12 is used to execute instructions to implement the method provided by any embodiment and any non-conflicting combination of the device protocol identification method of this application.

[0102] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of a computer-readable storage medium in an embodiment of this application. The computer-readable storage medium 20 in this embodiment stores instruction / program data 21. When executed, this instruction / program data 21 implements the method provided by any embodiment of the device protocol identification method of this application and any non-conflicting combination thereof. The instruction / program data 21 can be formed into a program file and stored in the storage medium 20 in the form of a software product, so that a computer device (which may be a personal computer, server, or network device, etc.) or processor can execute all or part of the steps of the methods in various embodiments of this application. The aforementioned storage medium 20 includes various media capable of storing program code, such as a USB flash drive, portable hard drive, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk, or terminal devices such as computers, servers, mobile phones, and tablets.

[0103] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only 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. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0104] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0105] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A method for suppressing electromagnetic interference in a power supply, characterized in that, The method includes: Detect the rate of change of the electrical parameters of the power supply; Based on the mapping relationship between the rate of change of the electrical parameters and the degree of spread, the degree of spread corresponding to the rate of change of the electrical parameters is determined, and the degree of spread is used to represent the degree of difference between the spectrum bandwidth after spread and the spectrum bandwidth before spread. The spectrum of the power supply is spread based on the degree of spread.

2. The electromagnetic interference suppression method according to claim 1, characterized in that, The determination of the expansion degree corresponding to the rate of change of the electrical parameter based on the mapping relationship between the rate of change of the electrical parameter and the expansion degree includes the following steps: Record the electromagnetic interference suppression rate of the expansion degree corresponding to different rates of change of electrical parameters; Based on the recorded data, a mapping model between the rate of change and the extent of expansion of various electrical parameters is established using machine learning algorithms; Determining the degree of expansion corresponding to the rate of change of the electrical parameters based on the mapping relationship between the rate of change and the degree of expansion includes: The rate of change of the electrical parameters of the power supply is input into the mapping model so as to predict the degree of expansion corresponding to the rate of change of the electrical parameters of the power supply.

3. The electromagnetic interference suppression method according to claim 1, characterized in that, The method further includes: The power supply is subjected to multi-stage filtering.

4. The electromagnetic interference suppression method according to claim 3, characterized in that, The multi-segment filtering process for the power supply includes: By detecting the fundamental frequency of the power supply, the high electromagnetic interference frequency band in the power supply's spectrum is identified, and the high electromagnetic interference frequency band is selected as the frequency band to be filtered. The filter cutoff frequency is set according to the frequency band to be filtered, so that the power supply is filtered by the filter cutoff frequency.

5. The electromagnetic interference suppression method according to claim 4, characterized in that, The step of setting a filter cutoff frequency according to the frequency band to be filtered, so as to filter the power supply through the filter cutoff frequency, includes: The inductive impedance value in the filter circuit is adjusted based on the filter cutoff frequency so that the filter circuit with adjusted inductive impedance can perform multi-segment filtering of the power signal based on the filter cutoff frequency.

6. The electromagnetic interference suppression method according to claim 3, characterized in that, The multi-segment filtering process for the power supply includes: Perform first harmonic processing on the input power signal; Electromagnetic interference on multiple harmonic components caused by the high rate of change of electrical parameters of the power supply is filtered.

7. An electromagnetic interference suppression device for a power supply, characterized in that, The device includes: The detection unit is used to detect the rate of change of the electrical parameters of the power supply. A spread spectrum parameter setting unit is used to determine the spread degree corresponding to the rate of change of the electrical parameters based on the mapping relationship between the rate of change of the electrical parameters and the spread degree, and to set the spread spectrum parameters based on the spread degree; and, The spreading unit is used to spread the power spectrum based on spreading parameters.

8. The apparatus according to claim 7, characterized in that, The device further includes: An input filter is disposed before the spread spectrum unit, and the input filter is used to perform multi-segment filtering on the power supply; The spreading unit is used to spread the power signal filtered by the input filter based on the spreading parameters.

9. The apparatus according to claim 8, characterized in that, The input filter includes a first harmonic circuit and multiple adjustable filter circuits connected in series after the first harmonic circuit. The parameters of each adjustable filter circuit are set according to the corresponding high-level harmonic spectrum.

10. The apparatus according to claim 7, characterized in that, The spread spectrum parameter setting unit is used to input the rate of change of the electrical parameters of the power supply into the mapping model, so as to predict the degree of spread corresponding to the rate of change of the electrical parameters of the power supply through the mapping model. The mapping model is trained using a machine learning algorithm.

Images