Electromagnetic interference model construction method based on whole vehicle electromagnetic environment simulation and application

Abstract

The invention provides an electromagnetic interference model construction method and application based on whole vehicle electromagnetic environment simulation, and the method comprises the steps: obtaining an electromagnetic disturbance excitation signal source of an electric vehicle, analyzing the bandwidth characteristics, obtaining the spectrum characteristics of an electromagnetic disturbance excitation signal, and extracting the characteristic value of the electromagnetic disturbance excitation signal; establishing a function relationship between the electromagnetic disturbance excitation signal and the characteristic value; constructing a whole vehicle electromagnetic environment simulation mathematical model composed of a power system electronic disturbance model, a whole vehicle three-dimensional grid geometric model and a human body simulation model, wherein the whole vehicle electromagnetic environment simulation mathematical model is used for analyzing a frequency response relation of the power system under electromagnetic disturbance excitation; and calculating the space electromagnetic field distribution of the electric vehicle by adopting the whole vehicle electromagnetic environment simulation mathematical model, and verifying the measurement result of the whole vehicle electromagnetic environment simulation mathematical model for evaluation. The application comprises evaluation of electromagnetic safety of the electric vehicle power system and electromagnetic compatibility design of the electric vehicle power system. The invention lays a foundation for the development of the electric vehicle technology in the future.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic interference analysis, and in particular to a method and application of building an electromagnetic interference model based on whole vehicle electromagnetic environment simulation. Background Art

[0002] Electromagnetic safety assessment plays a vital role in the design of electric vehicle power systems. Electromagnetic safety assessment can ensure that the related equipment of electric vehicle power systems will not have adverse effects on each other or other vehicle equipment when working, and also ensure that electric vehicles will not interfere with the external environment. Electromagnetic safety assessment requires the evaluation of the electromagnetic radiation level of the system under different working conditions to ensure that it meets the relevant safety standards. During the evaluation process, factors such as the switching frequency of power electronic devices, the working state of the system, and the driving environment of the vehicle need to be considered. At the same time, the evaluation results need to be verified and confirmed to ensure their accuracy and reliability. However, the existing electromagnetic safety assessment model has poor accuracy, resulting in unreasonable layout of electronic related devices, making the electromagnetic radiation intensity in the car high, which is harmful to human health; the device frequency response is unstable, resulting in poor stability of the power system operation.

[0003] Prior art 1, application number: CN 202410598667.X discloses a vehicle electromagnetic immunity test method and equipment based on a whole vehicle electromagnetic reverberation chamber, the method comprising: obtaining the sampling data received by the receiving antenna during the rotation of the stirring paddle of the whole vehicle electromagnetic reverberation chamber at the rated speed; calculating the autocorrelation coefficient when the stirring paddle rotates to different displacements based on the sampling data; determining the independent sample interval of the sampling based on the autocorrelation coefficient; determining the test rotation angle of the stirring paddle of the largest size based on the independent sample interval; verifying that the whole vehicle electromagnetic reverberation chamber meets the standard field uniformity requirements according to the test rotation angle of the stirring paddle of the largest size and calculating the field strength calibration data; and performing the automobile electromagnetic immunity test based on the field strength calibration data. Although it can effectively shorten the time of the automobile electromagnetic immunity test and improve the test efficiency. However, the optimization of the switching frequency and layout of the power electronic device is not achieved according to the evaluation results, so as to fail to achieve the purpose of reducing the electromagnetic radiation level, resulting in poor practical application effect of the scheme.

[0004] Prior art 2, application number: CN 202311336955.X discloses an electromagnetic shielding method for electric vehicles and electric vehicles, including: establishing a vehicle model of the electric vehicle, the vehicle model includes a body model, a center console, an audio device and an audio control line connected between the center console and the audio device; performing charging simulation on the vehicle model and obtaining electromagnetic induction data of the audio control line; determining the electromagnetic shielding weak section information of the audio control line according to the electromagnetic induction data; performing electromagnetic shielding operations on the electric vehicle according to the electromagnetic shielding weak section information. Although it can solve the problem in the related art that electromagnetic shielding cannot be performed for the electromagnetic shielding requirements of different areas of the vehicle audio, resulting in cost waste. However, only for the electromagnetic interference during the operation of the electric vehicle, the layout adjustment of the relevant electronic devices before safety is not achieved, which can easily lead to poor accuracy of electromagnetic interference shielding and unreasonable layout of the relevant electronic devices, affecting work efficiency and reducing space utilization.

[0005] Prior art three, application number: CN 202311159326.4 discloses a shielding test box for electromagnetic compatibility testing of new energy vehicles, including a reference box body, and adjustment controls for regulation are arranged on both sides of the reference box body, and a mounting frame is arranged at the rear end of the reference box body. The unfolding and winding actions of the reel and the first shielding cloth are adjusted by switching the start and stop of the electric appliance and the electromagnetic clutch, and the adsorption action and reflection action of the electromagnetic wave are switched to simulate the electromagnetic interference detection environment of the automobile detection components; and the detector is driven to perform rotation detection through the transmission action of the gear ring and the second gear and other components, and the data adapter and the control terminal are used for transmission action, although it is beneficial to improve the diversity test and comparison test data effect of electromagnetic compatibility, and realize automated test equipment. However, the function of the shielding test box is relatively simple, and only electromagnetic shielding measures are used to improve the electromagnetic environment in the car, and there is no relevant technology to realize the rational adjustment of the layout of electronic devices, and the occurrence of electromagnetic interference is not fundamentally eliminated, which makes the electromagnetic interference countermeasures ineffective.

[0006] At present, the existing technologies 1, 2 and 3 do not provide the unreasonable optimization and adjustment of the layout of electronic related devices, and cannot effectively reduce the electromagnetic field strength in electric vehicles. Therefore, the present invention provides an electromagnetic interference model construction method and application based on the electromagnetic environment simulation of the whole vehicle, which optimizes the layout and parameter setting of power electronic devices through accurate electromagnetic field simulation and testing, reduces the electromagnetic field strength of the vehicle driving space, and reduces the potential impact of electromagnetic radiation on the human body. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation, comprising the following steps:

[0008] Obtain the electromagnetic disturbance excitation signal source of the electric vehicle, analyze the bandwidth characteristics, obtain the spectrum characteristics of the electromagnetic disturbance excitation signal, and then extract the characteristic value of the electromagnetic disturbance excitation signal; establish the functional relationship between the electromagnetic disturbance excitation signal and the characteristic value;

[0009] Construct a whole vehicle electromagnetic environment simulation mathematical model consisting of a power system electronic disturbance model, a full vehicle three-dimensional mesh geometric model, and a human body simulation model to analyze the frequency response relationship of the power system under electromagnetic disturbance excitation;

[0010] The whole vehicle electromagnetic environment simulation mathematical model is used to calculate the spatial electromagnetic field distribution of electric vehicles, and the measurement results of the whole vehicle electromagnetic environment simulation mathematical model are verified and evaluated.

[0011] Optionally, the process of analyzing bandwidth characteristics includes the following steps:

[0012] Determine the source of the electromagnetic disturbance excitation signal to be analyzed, and use a spectrum analyzer to capture the spectrum characteristics of the electromagnetic disturbance excitation signal; collect the electromagnetic disturbance excitation signal under different speeds, load conditions or switching frequencies and different working conditions, and record and store the captured electromagnetic disturbance excitation signal waveform;

[0013] The time domain signal of the electromagnetic disturbance excitation signal is converted by using the fast Fourier transform to obtain the frequency domain representation of the electromagnetic disturbance excitation signal, and a set of complex numbers is output at the same time, representing the amplitude and phase of each frequency component; the spectrum, i.e. the amplitude information of each frequency in the time signal, is obtained by calculating the amplitude of the complex output, the frequency axis is established, the spectrum diagram is drawn, the frequency components are identified in the spectrum diagram, and the prominent peak and frequency range are obtained;

[0014] According to the spectrum diagram, the bandwidth of the electromagnetic disturbance excitation signal is defined, and the energy distribution and attenuation characteristics of the electromagnetic disturbance excitation signal within the frequency range are analyzed.

[0015] Optionally, the characteristic value extraction process of the electromagnetic disturbance excitation signal includes the following steps:

[0016] Each electromagnetic disturbance excitation signal source is placed in a simulation test platform of a power system to simulate the actual operating state of various speeds, loads and environmental conditions; sensors are arranged on each electromagnetic disturbance excitation signal source to record the electromagnetic disturbance excitation signal of each part under different working conditions in real time;

[0017] Determine a standard reference signal under a certain working condition, analyze the frequency response characteristics of the reference signal, obtain the gain and phase changes at different frequency points, and the corresponding time domain characteristics; extract the characteristic value from the time domain signal; calculate the bandwidth width and amplitude of the time domain signal, reconstruct the time domain signal according to the characteristic value, and compare it with the reference signal;

[0018] Extract the peak value and its peak frequency and corresponding peak time in the frequency domain signal, calculate the phase spectrum, and obtain the phase information at each frequency; extract the characteristic value from the phase spectrum;

[0019] Based on the selected reference signal, its phase spectrum is defined as the comparison benchmark, and the phase spectrum of the electromagnetic disturbance excitation signal under different working conditions is differentially processed with the reference phase spectrum. The data in the phase spectrum is compared point by point to generate a new spectrum, which represents the difference between the two phase spectra at each frequency point. The collected differential phase spectrum will be used in the establishment of the electromagnetic disturbance model to quantify the difference between the actual electromagnetic disturbance excitation signal and the reference signal.

[0020] Optionally, phase information at each frequency is obtained, including the phase of the zero frequency, the DC component, and the phase delay of each frequency component.

[0021] Optionally, eigenvalues ​​are extracted from the phase spectrum, including minimum phase frequency and phase delay.

[0022] Optionally, the construction process of the simulation test platform includes the following steps:

[0023] Identify the working conditions that need to be simulated and the types of electromagnetic disturbances that need to be tested, select the motor, transmission and load equipment, and select the electromagnetic interference source components to generate different types of electromagnetic disturbance signals; select current sensors, vibration sensors and voltage sensors; equip data acquisition cards and computers for real-time monitoring, recording and processing of experimental data;

[0024] Build the physical structure of the simulation test platform, including fixing the motor, transmission and load equipment; arrange sensors to capture the electromagnetic disturbance signals of related components; connect various components according to the electrical drawings, including the connection between the motor and the power supply, the connection of the load, and the connection between the sensor and the data acquisition system; install the software on the data acquisition system and configure the parameters to read the sensor signals;

[0025] Carry out preliminary debugging, check whether the connection is operating normally, and calibrate the sensor; for different operating conditions, clarify the speed, load and environmental parameter settings under each condition, prepare execution steps, data recording tables and analysis methods, record electromagnetic disturbance excitation signals in real time, store the collected data and perform preliminary analysis to identify signal characteristics.

[0026] Optionally, the process of analyzing the frequency response characteristics of the reference signal includes the following steps:

[0027] The maximum amplitude value, the root mean square value and the zero crossing rate reflecting the amplitude of the reference signal are calculated; the root mean square value is used to represent the effective value of the reference signal, and the zero crossing rate calculates the frequency of the zero crossing point in the reference signal; the reference signal is subjected to a fast Fourier transform to convert the reference signal from the time domain to the frequency domain;

[0028] The ratio of the input signal to the output signal of the reference signal is calculated to obtain the gain calculation result of the reference signal, and the phase variation characteristics of the reference signal are obtained by extracting the phase of each frequency point;

[0029] Calculate the amplitude of the reference signal spectrum, determine the frequency range where the amplitude decays to a certain value under the frequency response, and record the value with the largest amplitude in the spectrum; use the inverse fast Fourier transform to convert the frequency domain signal back to the time domain, and reconstruct the signal using the frequency response characteristics obtained from the frequency domain; compare with the reference signal: compare the reconstructed signal with the initial reference signal, and analyze the consistency, similarity, or difference of the signal to identify any performance changes or distortions.

[0030] Optionally, the process of establishing a functional relationship between the electromagnetic disturbance excitation signal and the characteristic value includes the following steps:

[0031] Use finite element software to import the corresponding geometric model; the geometric model reflects the shape, size and relationship of the structure of each component of the power system; divide the geometric model into finite elements and use grids at the position where the excitation signal is applied;

[0032] Set boundary conditions and apply reference excitation signals to the geometric model to simulate the forces or displacements that each component would experience under real conditions; use a dynamic analysis solver to configure the parameters required for the calculation process; perform finite element analysis to calculate the response of the structure under specific excitation;

[0033] The simulation results of the finite element analysis are analyzed to extract the frequency response characteristics. The obtained reference signal and response signal are Fourier transformed from the time domain to the frequency domain to extract the frequency components. The important eigenvalues ​​are extracted from the spectrum, and the functional relationship between the excitation signal and the eigenvalue is established.

[0034] The present invention provides an application of an electromagnetic interference model in the calculation of the spatial electromagnetic field distribution of an electric vehicle. The electromagnetic interference model is constructed by the electromagnetic interference model construction method based on the whole vehicle electromagnetic environment simulation.

[0035] The present invention provides an application of an electromagnetic interference model in the design of electromagnetic compatibility of an electric vehicle power system. The electromagnetic interference model is constructed by the electromagnetic interference model construction method based on whole vehicle electromagnetic environment simulation.

[0036] The present invention obtains the electromagnetic disturbance excitation signal source and spectrum characteristic analysis, analyzes the electromagnetic disturbance signal source emitted by each electronic component (motor, controller, charger, etc.) in the electric vehicle, extracts its spectrum characteristics and characteristic values, including measuring and analyzing the electromagnetic interference signals generated at different working frequencies, and better understands the working characteristics of each component and its impact on the electromagnetic environment. The significance achieved: It provides a key data basis for the subsequent electromagnetic environment simulation implementation, provides a basis for identifying and classifying the properties of electromagnetic interference signals, and is crucial to understanding potential problems; by deeply analyzing the spectrum characteristics of electromagnetic disturbance signals, the interference source can be identified, thereby providing guidance for the subsequent design of appropriate electromagnetic compatibility (EMC) countermeasures. For example, by achieving effective shielding or filtering, electromagnetic interference between systems can be reduced. Construct a whole vehicle electromagnetic environment simulation mathematical model, establish a comprehensive whole vehicle electromagnetic environment simulation mathematical model, including the electronic disturbance model of the power system, the three-dimensional grid geometric model of the whole vehicle, and the human body simulation model. This model combination can accurately reflect the electromagnetic response characteristics of electric vehicles under various working conditions; by simulating different electromagnetic disturbance excitations, analyze the frequency response of the whole vehicle and its subsystems (such as the power system) under these excitations, and obtain specific information on how to reduce interference. Significance achieved: Through the simulation model, the electromagnetic environment of the whole vehicle can be comprehensively evaluated, the interaction of each component under electromagnetic disturbance can be understood, and a basis can be provided for optimizing the design; the establishment of a mathematical model can help to simulate and predict the impact of electromagnetic interference faster, reduce the design and testing cycle, and accelerate the product development process. Calculate the spatial electromagnetic field distribution and verification model of electric vehicles, use the whole vehicle electromagnetic environment simulation mathematical model to calculate the electromagnetic field distribution of electric vehicles under various working conditions, and specifically analyze the overall and local electromagnetic environment characteristics of electric vehicles; verify the accuracy and reliability of the whole vehicle electromagnetic environment simulation model by comparing with the actual measurement results, and analyze possible deviations and improvement measures. Significance achieved: Provide a reliable basis for final design verification and decision-making, and ensure that electric vehicles meet industry standards in terms of electromagnetic compatibility; ensure the accuracy of the simulation model, further improve the functional safety of electric vehicles, and reduce the potential dangers of electronic equipment and their occupants; effective model verification and data analysis will provide feedback for subsequent research on electromagnetic interference of electric vehicles, promote continuous iteration and optimization of the model, and improve the overall design quality.

[0037] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0038] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 This is a flow chart of a method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation in Example 1 of the present invention;

[0041] Figure 2 A process diagram of analyzing bandwidth characteristics in Embodiment 2 of the present invention;

[0042] Figure 3 This is a diagram of a process for extracting characteristic values ​​of an electromagnetic disturbance excitation signal in Embodiment 3 of the present invention;

[0043] Figure 4 This is a diagram of the construction process of the simulation test platform in Example 4 of the present invention;

[0044] Figure 5 is a process diagram of analyzing the frequency response characteristics of a reference signal in Embodiment 5 of the present invention;

[0045] Figure 6 This is a process diagram for establishing a functional relationship between an electromagnetic disturbance excitation signal and a characteristic value in Embodiment 6 of the present invention;

[0046] Figure 7 This is a flow chart for constructing a mathematical model for simulating the electromagnetic environment of a whole vehicle in Example 7 of the present invention. DETAILED DESCRIPTION

[0047] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0048] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0049] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as described in detail. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and do not have to be used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0050] Example 1: Figure 1 As shown, an embodiment of the present invention provides a method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation, comprising the following steps:

[0051] S100: obtaining an electromagnetic disturbance excitation signal source of the electric vehicle, analyzing the bandwidth characteristics, obtaining the spectrum characteristics of the electromagnetic disturbance excitation signal, and then extracting the characteristic value of the electromagnetic disturbance excitation signal; establishing a functional relationship between the electromagnetic disturbance excitation signal and the characteristic value;

[0052] S200: Construct a whole vehicle electromagnetic environment simulation mathematical model consisting of a power system electronic disturbance model, a full vehicle three-dimensional mesh geometric model, and a human body simulation model to analyze the frequency response relationship of the power system under electromagnetic disturbance excitation;

[0053] S300: The whole vehicle electromagnetic environment simulation mathematical model is used to calculate the spatial electromagnetic field distribution of electric vehicles, and the measurement results of the whole vehicle electromagnetic environment simulation mathematical model are verified and evaluated.

[0054] The working principle and beneficial effects of the above technical solution are as follows: In this embodiment, the electromagnetic disturbance excitation signal source of the electric vehicle is first obtained, the bandwidth characteristics are analyzed, the spectrum characteristics of the electromagnetic disturbance excitation signal are obtained, and then the characteristic value of the electromagnetic disturbance excitation signal is extracted; the functional relationship between the electromagnetic disturbance excitation signal and the characteristic value is established; secondly, a whole vehicle electromagnetic environment simulation mathematical model composed of a power system electronic disturbance model, a three-dimensional grid geometric model of the whole vehicle and a human body simulation model is constructed to analyze the frequency response relationship under the electromagnetic disturbance excitation of the power system; finally, the whole vehicle electromagnetic environment simulation mathematical model is used to calculate the spatial electromagnetic field distribution of the electric vehicle, and the measurement results of the whole vehicle electromagnetic environment simulation mathematical model are verified and evaluated. Step S100 of the above scheme obtains the electromagnetic disturbance excitation signal source and spectrum characteristic analysis, and extracts its spectrum characteristics and characteristic values ​​by analyzing the electromagnetic disturbance signal source emitted by each electronic component (motor, controller, charger, etc.) in the electric vehicle, including measuring and analyzing the electromagnetic interference signals generated at different working frequencies, so as to better understand the working characteristics of each component and its impact on the electromagnetic environment. Significance achieved: It provides a key data basis for the subsequent electromagnetic environment simulation implementation, provides a basis for identifying and classifying the nature of electromagnetic interference signals, and is crucial to understanding potential problems; by deeply analyzing the spectrum characteristics of electromagnetic disturbance signals, the interference source can be identified, thereby providing guidance for the subsequent design of appropriate electromagnetic compatibility (EMC) countermeasures. For example, by achieving effective shielding or filtering, the electromagnetic interference between systems can be reduced. Step S200 constructs a mathematical model for the electromagnetic environment simulation of the whole vehicle, and establishes a comprehensive mathematical model for the electromagnetic environment simulation of the whole vehicle, including an electronic disturbance model of the power system, a three-dimensional mesh geometric model of the whole vehicle, and a human body simulation model. This model combination can accurately reflect the electromagnetic response characteristics of electric vehicles under various working conditions; by simulating different electromagnetic disturbance excitations, the frequency response of the whole vehicle and its subsystems (such as the power system) under these excitations is analyzed to obtain specific information on how to reduce interference. Significance achieved: Through the simulation model, a comprehensive evaluation can be conducted on the electromagnetic environment of the whole vehicle, the interaction of each component under electromagnetic disturbance can be understood, and a basis can be provided for optimizing the design; the establishment of a mathematical model helps to simulate and predict the impact of electromagnetic interference faster, reduce the design and testing cycle, and accelerate the product development process. Step S300 calculates the spatial electromagnetic field distribution of the electric vehicle and verifies the model. The electromagnetic field distribution of the electric vehicle under various working conditions is calculated using the whole vehicle electromagnetic environment simulation mathematical model, and the overall and local electromagnetic environment characteristics of the electric vehicle are specifically analyzed. By comparing with the actual measurement results, the accuracy and reliability of the whole vehicle electromagnetic environment simulation model are verified, and possible deviations and improvement measures are analyzed.Significance achieved: Provide a reliable basis for final design verification and decision-making, and ensure that electric vehicles meet industry standards in terms of electromagnetic compatibility; ensure the accuracy of the simulation model, further improve the functional safety of electric vehicles, and reduce the potential dangers of electronic equipment and their occupants; effective model verification and data analysis will provide feedback for subsequent electric vehicle electromagnetic interference research, promote continuous iteration and optimization of the model, and improve the overall design quality.

[0055] This embodiment includes the establishment of a mathematical model for the electromagnetic environment simulation of the whole vehicle and the analysis of the frequency response under the electromagnetic disturbance excitation of the power system. Specifically, it includes: analyzing the working characteristics of each component of the power system, the dynamic response time of the system under frequent starting / stopping, acceleration / deceleration and stable operation conditions, the characteristics of the overload signal, etc., analyzing the working principle of the system under low-frequency conditions, establishing a lumped parameter low-frequency circuit mathematical model of the power system, and in high-frequency conditions, comprehensively considering the radiation model of the wire antenna, the aperture model and the transmission line coupling model, correcting the adaptability of the power system model, establishing a three-dimensional mesh geometric model of the whole vehicle, dividing the mesh to discretize the geometric model of the whole vehicle, establishing a human body simulation model, and on this basis, deriving a mathematical model for the electromagnetic environment simulation of the whole vehicle and analyzing its dynamic frequency response.

[0056] This embodiment optimizes the layout and parameter settings of power electronic devices through precise electromagnetic field simulation and testing, reduces the electromagnetic field strength in the vehicle driving space, and reduces the potential impact of electromagnetic radiation on the human body; optimizes the frequency response characteristics of power electronic devices according to the changes in switching frequency under different working conditions, ensuring that the power system can operate stably and efficiently under different working conditions; optimizes the control strategy of power electronic devices through in-depth research on signal laws, reduces signal noise and interference, and improves the overall performance of the power system; enhances electromagnetic safety: through electromagnetic safety assessment and application, ensures that electric vehicles can meet electromagnetic safety standards under various working conditions, and reduces the impact of electromagnetic radiation on vehicles and drivers and passengers.

[0057] In summary, this embodiment not only improves the scientificity and systematicness of the electromagnetic compatibility design of electric vehicles through hierarchical analysis and model construction, but also provides a feasible method and basis for related verification, optimization and troubleshooting, laying the foundation for the development of future electric vehicle technology.

[0058] Example 2: Figure 2 As shown, based on Example 1, the process of analyzing bandwidth characteristics provided by the embodiment of the present invention includes the following steps:

[0059] S101: determining the source of the electromagnetic disturbance excitation signal to be analyzed, and using a spectrum analyzer to capture the spectrum characteristics of the electromagnetic disturbance excitation signal; collecting the electromagnetic disturbance excitation signal under different working conditions such as different speeds, load conditions or switching frequencies, and recording and storing the captured electromagnetic disturbance excitation signal waveform;

[0060] Among them, the electromagnetic disturbance excitation signal source includes: drive motor and its components: under different switching frequencies, analyze the intensity and characteristics of the disturbance excitation signal generated by the drive motor through the alternating magnetic field to convert electrical energy and mechanical energy, and analyze the bandwidth of its disturbance excitation signal; motor controller (inverter) and its components: analyze the switching operating frequency of the IGBT power tube, analyze the influence of the drive module and the control module on the overall disturbance rise, and analyze the bandwidth of its disturbance excitation signal; battery pack: analyze the influence of the battery management system (BMS) on other related signals when collecting the voltage, temperature and other signals of each battery cell in real time, and analyze the bandwidth of the disturbance excitation signal generated when the BMS adjusts and controls the power balance of each single cell; on-board charger: the on-board charger (OBC) converts the alternating current into high-voltage direct current through AC / DC rectification to charge the battery pack. The rectification process will generate a large number of interference signals, and analyze their influence on narrowband testing; DC / DC conversion module: the function of the module is to convert high-voltage and low-current into low-voltage 12 / 24V high-current output. The power device and control module are narrow-band disturbance excitation signal sources, and analyze their influence on narrowband testing;

[0061] S102: using fast Fourier transform to transform the time domain signal of the electromagnetic disturbance excitation signal, obtaining the frequency domain representation of the electromagnetic disturbance excitation signal, and outputting a set of complex numbers, representing the amplitude and phase of each frequency component; by calculating the amplitude of the complex number output, obtaining the spectrum, that is, the amplitude information of each frequency in the time signal, establishing the frequency axis, drawing the spectrum diagram, identifying the frequency components in the spectrum diagram, and obtaining the prominent peak and frequency range;

[0062] S103: According to the frequency spectrum, define the bandwidth of the electromagnetic disturbance excitation signal, and analyze the energy distribution and attenuation characteristics of the electromagnetic disturbance excitation signal within the frequency range.

[0063] The working principle and beneficial effects of the above technical solution are as follows: In this embodiment, the electromagnetic disturbance excitation signal source to be analyzed is first determined, and the spectrum characteristics of the electromagnetic disturbance excitation signal are captured by a spectrum analyzer; the electromagnetic disturbance excitation signal is collected under different working conditions such as different speeds, load conditions or switching frequencies, and the captured electromagnetic disturbance excitation signal waveform is recorded and stored; wherein, the electromagnetic disturbance excitation signal source includes: a drive motor and its components: under different switching frequencies, the intensity and characteristics of the disturbance excitation signal generated by the drive motor through the alternating magnetic field to convert electrical energy and mechanical energy are analyzed, and the bandwidth of the disturbance excitation signal is analyzed; a motor controller (inverter) and its components: analyzing the switching operating frequency of the IGBT power tube, analyzing the influence of the drive module and the control module on the overall rise of the disturbance, and analyzing the bandwidth of the disturbance excitation signal; a battery pack: analyzing the voltage, temperature and other signals of each battery cell collected in real time by the battery management system (BMS); The impact on other related signals, and at the same time analyze the bandwidth of the interference excitation signal generated when the BMS adjusts and controls the power balance of each single battery; On-board charger: The on-board charger (OBC) converts AC power into high-voltage DC power to charge the battery pack through AC / DC rectification. The rectification process will generate a large number of interference signals. Analyze its impact on narrowband testing; DC / DC conversion module: The function of the module is to convert high-voltage and low-current into low-voltage 12 / 24V high-current output. The power device and control module are narrow-band interference excitation signal sources. Analyze their impact on narrowband testing; secondly, use fast Fourier transform to convert the time domain signal of the electromagnetic interference excitation signal to obtain the frequency domain representation of the electromagnetic interference excitation signal, identify the frequency components in the spectrum diagram, and obtain the prominent peaks and frequency ranges; finally, according to the spectrum diagram, define the bandwidth of the electromagnetic interference excitation signal, and analyze the energy distribution and attenuation characteristics of the electromagnetic interference excitation signal within the frequency range. Step S101 of the above scheme determines the signal source and performs signal acquisition, and determines the source of the electromagnetic disturbance excitation signal, including the drive motor, motor controller (inverter), battery pack, on-board charger and DC / DC conversion module; ensures the depth and comprehensiveness of the analysis, and the electromagnetic disturbance characteristics of all key components are considered; collects electromagnetic disturbance signals under different working conditions (such as speed, load, switching frequency, etc.). Through such diversified tests, more representative signals can be captured to reflect the electromagnetic interference characteristics of the equipment during actual use; the electromagnetic disturbance signal waveform captured by the spectrum analyzer provides a rich data basis for subsequent spectrum analysis; the significance achieved: by determining the signal source and changing the working state, the role of each component in the electromagnetic disturbance can be comprehensively and systematically analyzed, and detailed information can be provided for potential noise sources; provide basic data for model development: the recorded data will become the basis for simulation and modeling, which will help the subsequent electromagnetic compatibility optimization and design improvement.Step S102 performs spectrum analysis and extracts frequency components. The time domain waveform of the electromagnetic disturbance signal is analyzed by fast Fourier transform (FFT) to obtain frequency domain representation, so that the complex time domain signal is presented in the form of frequency components, which is convenient for further analysis; the main frequency components, peak values ​​and other frequency characteristics in the spectrum diagram can be clearly identified. This frequency information is very important for understanding the nature of electromagnetic disturbance. Significance achieved: Through frequency domain analysis, the amplitude information of different frequency components can be quantified, and it is clear which frequency bands are more significantly disturbed, thereby providing a basis for subsequent design and protection measures; when designing electromagnetic compatibility control measures, understanding the information of harmonics and their amplitudes can help designers formulate more effective countermeasures to reduce the impact of electromagnetic interference. Step S103 defines bandwidth and energy distribution analysis. According to the identified frequency components, the bandwidth of the electromagnetic disturbance excitation signal is established, and its -3dB bandwidth and other parameters are defined, which helps to quantify the range of the interference signal; through the spectrum diagram, the energy distribution, attenuation and potential impact range of the signal within the frequency range are analyzed, which helps to understand the specific impact of interference on the system. Significance achieved: It is possible to quantify the impact range and intensity of interference signals, providing a basis for evaluating the impact on system operation stability; based on the analysis results of bandwidth and energy distribution, effective design and improvement plans can be formulated to improve the electromagnetic compatibility of various components of electric vehicles and reduce the impact of electromagnetic interference on the system.

[0064] In summary, the analysis of the bandwidth characteristics of electromagnetic disturbance excitation signals in this embodiment not only provides a deeper understanding of electric vehicles and their electrical systems, but also promotes the improvement of technical means for electromagnetic interference control, thereby laying a solid foundation for improving the electromagnetic compatibility and reliability of the entire vehicle. Through this entire process, potential risks can be identified and necessary technical measures can be taken to optimize the design and reduce the impact of electromagnetic interference on overall performance.

[0065] Example 3: Figure 3 As shown, based on Example 1, the characteristic value extraction process of the electromagnetic disturbance excitation signal provided in the embodiment of the present invention includes the following steps:

[0066] S104: placing each electromagnetic disturbance excitation signal source in a simulation test platform of a power system to simulate the actual operating state of various speeds, loads and environmental conditions; arranging sensors on each electromagnetic disturbance excitation signal source to record the electromagnetic disturbance excitation signal of each part under different conditions in real time;

[0067] S105: determining a standard reference signal under a certain working condition, analyzing the frequency response characteristics of the reference signal, obtaining gain and phase changes at different frequency points, and corresponding time domain characteristics; extracting characteristic values ​​from the time domain signal, such as the maximum value, root mean square value (RMS) and zero crossing rate of the signal; calculating the bandwidth width (frequency range representing the energy distribution of the signal) and the amplitude size (maximum amplitude value) of the time domain signal, reconstructing the time domain signal according to the characteristic values, and comparing it with the reference signal;

[0068] S106: extracting the peak value and its peak frequency and corresponding peak time from the frequency domain signal, calculating the phase spectrum, and obtaining the phase information at each frequency, including the phase of the zero frequency, the DC component, and the phase delay of each frequency component; extracting characteristic values ​​from the phase spectrum, including the minimum phase frequency and the phase delay, etc.;

[0069] S107: Based on the selected reference signal, define its phase spectrum as a comparison benchmark, perform differential processing on the phase spectrum of the electromagnetic disturbance excitation signal under different working conditions and the reference phase spectrum, compare the data in the phase spectrum point by point, and generate a new spectrum representing the difference between the two phase spectra at each frequency point; the collected differential phase spectrum will be used in the establishment of the electromagnetic disturbance model to quantify the difference between the actual electromagnetic disturbance excitation signal and the reference signal.

[0070] The working principle and beneficial effects of the above technical solution are as follows: In this embodiment, each electromagnetic disturbance excitation signal source is first placed in a simulation test platform of a power system to simulate the actual operating state of various speeds, loads and environmental conditions; sensors are arranged on each electromagnetic disturbance excitation signal source to record the electromagnetic disturbance excitation signals of each part under different working conditions in real time, and the sensors include current sensors, vibration sensors and voltage sensors; secondly, a standard reference signal under a certain working condition is determined, and the frequency response characteristics of the reference signal are analyzed to obtain gain and phase changes at different frequency points, as well as corresponding time domain characteristics; characteristic values ​​are extracted from the time domain signal, such as the maximum value, root mean square value (RMS) and zero crossing rate of the signal; the bandwidth width (frequency range representing the energy distribution of the signal) and the amplitude of the time domain signal are calculated. Small (highest amplitude value), according to the characteristic value, reconstruct the time domain signal and compare it with the reference signal; then extract the peak value and its peak frequency and corresponding peak time in the frequency domain signal, calculate the phase spectrum, obtain the phase information at each frequency, including the phase of the zero frequency, the DC component and the phase delay of each frequency component; extract the characteristic value from the phase spectrum, including the minimum phase frequency and phase delay, etc.; finally, based on the selected reference signal, define its phase spectrum as the comparison benchmark, perform differential processing on the phase spectrum of the electromagnetic disturbance excitation signal under different working conditions and the reference phase spectrum, compare the data in the phase spectrum point by point, and generate a new spectrum, which represents the difference between the two phase spectra at each frequency point; the collected differential phase spectrum will be used in the establishment of the electromagnetic disturbance model to quantify the difference between the actual electromagnetic disturbance excitation signal and the reference signal. Step S104 of the above scheme constructs a simulation test platform and data acquisition, builds a test platform that can simulate different electrical and mechanical working conditions, and monitors the performance of multiple electromagnetic disturbance excitation signal sources in real time through sensors; the arrangement of sensors (such as current, vibration, voltage sensors, etc.) ensures comprehensive data acquisition, reflecting the actual operating status of the system under different conditions. Through the simulation of multiple working conditions, the characteristics of electromagnetic interference under various speeds, loads and environmental conditions can be identified, and a large amount of real and effective experimental data can be obtained for subsequent analysis and comparison; the simulation of actual operating conditions helps to deeply understand the performance of the equipment under various operating conditions and guide the optimization and troubleshooting of the equipment. Step S105: Reference signal definition and time domain feature extraction, select the reference signal under standard working conditions to clarify the basic characteristics of the signal, and obtain the gain and phase changes through frequency response feature analysis; extract characteristic values ​​(such as maximum value, RMS, zero crossing rate, etc.) from the time domain signal, and calculate the bandwidth and amplitude to depict the signal characteristics as a whole. Significance: A clear reference signal provides a benchmark for evaluating other signals and improves the accuracy of the analysis; through the extraction of time domain characteristic values, the strength and changes of the signal can be evaluated in a timely manner, providing a basis for equipment fault diagnosis, operating status monitoring and optimized design.Step S106: Frequency domain analysis and phase feature extraction, convert the time domain signal into a frequency domain signal, extract frequency domain features such as peak value, peak frequency, peak time and phase information, including zero frequency and phase delay of each frequency component; analyze the phase spectrum and extract characteristic values ​​from it, such as minimum phase frequency, phase delay, etc.; frequency domain analysis can reveal the characteristics of the signal at different frequencies, helping to identify and understand complex electromagnetic disturbance sources; phase information is crucial for understanding the performance of dynamic systems, and can be used to improve motor control, precise tuning and reduce system instability. S107 differential phase spectrum processing and model establishment, after defining the phase spectrum of the standard reference signal, differential processing is performed, and the phase spectrum under different working conditions is compared with the reference phase spectrum to generate a differential phase spectrum; providing a quantitative difference index, which is helpful for further model establishment and constructing an accurate description of the actual electromagnetic disturbance excitation signal. Differential phase spectrum analysis can clearly reveal the phase difference caused by changes in operating conditions, thereby providing scientific support for subsequent electromagnetic disturbance modeling; this process has important practical application value for identifying the vulnerable links of the system, improving electromagnetic compatibility and improving product quality.

[0071] In summary, the characteristic value extraction process of the electromagnetic disturbance excitation signal in this embodiment provides comprehensive support for power system design, troubleshooting and performance evaluation through reasonable step design and in-depth analysis. It not only improves the reliability of the system, but also promotes the stable operation of power equipment in harsh environments. At the same time, through scientific data analysis and modeling, targeted guidance can be provided for future design and improvement work, improving overall engineering efficiency and quality.

[0072] Example 4: Figure 4 As shown, based on Example 3, the construction process of the simulation test platform provided in the embodiment of the present invention includes the following steps:

[0073] S1041: Identify the working conditions to be simulated and the types of electromagnetic disturbances to be tested, select motors (e.g. asynchronous motors, DC motors), transmissions and load devices, select electromagnetic interference source components, such as power supply jammers, signal generators, etc., to generate different types of electromagnetic disturbance signals; select current sensors, vibration sensors and voltage sensors, etc.; equip data acquisition cards and computers for real-time monitoring, recording and processing of experimental data;

[0074] S1042: Build the physical structure of the simulation test platform, including fixing the motor, transmission and load equipment; arrange sensors to capture the electromagnetic disturbance signals of related components; connect various components according to the electrical drawings, including the connection between the motor and the power supply, the connection of the load, the connection between the sensor and the data acquisition system, etc.; install the software on the data acquisition system and configure the parameters to read the sensor signals;

[0075] S1043: Perform preliminary debugging, check whether the connection is operating normally, and calibrate the sensor; for different operating conditions, clarify the speed, load and environmental parameter settings under each condition, prepare execution steps, data recording tables and analysis methods, record electromagnetic disturbance excitation signals in real time, store the collected data and perform preliminary analysis to identify signal characteristics.

[0076] The working principle and beneficial effects of the above technical solution are as follows: In this embodiment, the working conditions to be simulated and the types of electromagnetic disturbances to be tested are first clarified, and the motor (such as asynchronous motor, DC motor), transmission and load equipment are selected, and the electromagnetic interference source components, such as power supply interference instrument, signal generator, etc., are selected to generate different types of electromagnetic disturbance signals; current sensors, vibration sensors and voltage sensors are selected; data acquisition cards and computers are equipped for real-time monitoring, recording and processing of experimental data; secondly, the physical structure of the simulation test platform is built, including fixing the motor, transmission and load equipment; sensors are arranged to capture the electromagnetic disturbance signals of related components; according to the electrical drawings, various components are connected, including the connection between the motor and the power supply, the connection of the load, the connection between the sensor and the data acquisition system, etc.; software is installed on the data acquisition system, and parameters are configured to read the sensor signal; finally, preliminary debugging is performed to check whether the connection is operating normally, and the sensor is calibrated; for different operating conditions, the speed, load and environmental parameter settings under each condition are clarified, execution steps, data recording tables and analysis methods are prepared, electromagnetic disturbance excitation signals are recorded in real time, the collected data are stored and preliminarily analyzed, and signal characteristics are identified. Step S1041 of the above scheme clarifies the requirements and component selection, and provides clear goals and directions for subsequent experiments by clarifying the working conditions and electromagnetic disturbance types that need to be simulated; selects appropriate motors (such as asynchronous motors, DC motors), transmissions, load devices, and electromagnetic interference sources (such as signal generators and power supply jammers) according to the requirements; selects current sensors, vibration sensors, and voltage sensors to ensure that the different characteristics of electromagnetic disturbances can be fully captured; and prepares data acquisition cards and computers to achieve real-time monitoring and processing of signals. It lays the foundation for the systematic design of the entire experiment, ensures that the equipment used can meet specific research needs, and thus provides guarantees for the successful implementation of the experiment; by selecting suitable sensors and data acquisition equipment, the accuracy and reliability of the collected data can be ensured, and more effective signal analysis and model building can be promoted. Step S1042: Physical structure construction and connection. The physical structure of the experimental platform includes fixing the motor, transmission and load to ensure that the equipment is firm and stable, and avoid data fluctuations caused by equipment instability during the test; according to the design requirements, the sensors are arranged reasonably to capture important signals at the optimal position to ensure that the recorded electromagnetic interference signals can fully reflect the system status; the equipment is connected according to the electrical drawings, and the required software is installed on the data acquisition system to configure parameters to realize the reading of sensor signals. Through reasonable construction and layout, the operability of the experiment and the efficiency of data acquisition can be improved, and the accuracy and repeatability of subsequent experimental data can be guaranteed; a stable physical environment and accurate electrical connection help ensure the consistency of the experiment, which is particularly important for analyzing the characteristics of electromagnetic interference and its changes.Step S1043 debugging, calibration and data collection, by checking whether the electrical connection is operating normally and calibrating the sensor, ensure that the entire system can operate as expected, and the accuracy and reliability of data monitoring meet the standards; clarify the speed, load and other environmental parameters under different operating conditions, and make detailed execution steps, data recording tables and analysis methods; record the electromagnetic disturbance excitation signal in real time, store the collected data, and conduct preliminary analysis to identify the characteristics of the signal. Debugging and calibration ensure the validity of the data, make the subsequent analysis credible, and help to discover potential problems in the system; by clarifying the data recording and analysis methods, establish a systematic research foundation, and ensure that the subsequent signal feature extraction and modeling work is more scientific and systematic.

[0077] In summary, the construction process of the simulation test platform of this embodiment is a relatively complex project, involving multiple steps from requirement clarification to system debugging. Each step has its specific technical effect and significance, and the steps are closely linked, laying a solid foundation for the success of the experiment. Through a systematic and scientific construction process, not only the efficiency of the test and the accuracy of data collection are improved, but also reliable empirical evidence is provided for subsequent electromagnetic disturbance analysis, modeling and optimization.

[0078] Example 5: Figure 5 As shown, based on Example 3, the process of analyzing the frequency response characteristics of the reference signal provided in the embodiment of the present invention includes the following steps:

[0079] S1051: Calculate the maximum amplitude value, root mean square value and zero crossing rate reflecting the amplitude of the reference signal; the root mean square value is used to represent the effective value of the reference signal, and the zero crossing rate calculates the frequency of the zero crossing point in the reference signal; perform fast Fourier transform on the reference signal to convert the reference signal from the time domain to the frequency domain;

[0080] S1052: Calculate the ratio of the input signal to the output signal of the reference signal to obtain a gain calculation result of the reference signal, and obtain a phase variation characteristic of the reference signal by extracting the phase of each frequency point;

[0081] S1053: Calculate the amplitude of the reference signal spectrum, determine the frequency range when the amplitude decays to a certain value under the frequency response, and record the value with the largest amplitude in the spectrum; use inverse fast Fourier transform to convert the frequency domain signal back to the time domain, and reconstruct the signal using the frequency response characteristics (gain and phase information) obtained from the frequency domain; compare with the reference signal: compare the reconstructed signal with the initial reference signal, analyze the consistency, similarity or difference of the signal to identify any performance changes or distortions.

[0082] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first calculates the maximum amplitude value, root mean square value and zero crossing rate reflecting the amplitude of the reference signal; the root mean square value is used to represent the effective value of the reference signal, and the zero crossing rate calculates the frequency of the zero crossing point in the reference signal; the reference signal is subjected to a fast Fourier transform to convert the reference signal from the time domain to the frequency domain; secondly, the ratio of the input signal to the output signal of the reference signal is calculated to obtain the gain calculation result of the reference signal, and the phase change characteristics of the reference signal are obtained by extracting the phase of each frequency point; finally, the amplitude of the reference signal spectrum is calculated to determine the frequency range when the amplitude decays to a certain value under the frequency response, and the value with the largest amplitude in the spectrum is recorded; the frequency domain signal is converted back to the time domain using an inverse fast Fourier transform, and the frequency response characteristics (gain and phase information) obtained from the frequency domain are used to reconstruct the signal; compared with the reference signal: the reconstructed signal is compared with the initial reference signal to analyze the consistency, similarity or difference of the signal to identify any performance changes or distortions. Step S1051 of the above scheme extracts time domain features and converts them into FFT, capturing the maximum amplitude of the signal to reflect the peak characteristics of the signal; the root mean square value (RMS) calculation represents the effective value of the signal, which can reflect the energy content of the signal in a stable manner and is suitable for describing irregular waveforms; quantifying the frequency change characteristics of the signal helps to understand the waveform characteristics and dynamic changes of the signal; converting the time domain signal into a frequency domain representation so that the spectrum characteristics of the signal can be analyzed is the basis for frequency response analysis. By extracting and quantifying the time domain features (maximum amplitude, RMS, zero crossing rate), a preliminary understanding of the dynamic characteristics and energy distribution of the signal can be provided, laying the foundation for subsequent analysis; the implementation of FFT enables the signal to be analyzed more deeply in the frequency domain, realizing accurate identification and evaluation of frequency components. Step S1052 Gain and phase feature analysis is obtained by calculating the ratio of the input and output signal amplitudes, reflecting the amplification or attenuation characteristics of the system at a specific frequency; extracting the phase of each frequency point to obtain the delay and phase offset information of the signal transmission is helpful to evaluate the phase response of the signal at different frequencies. The calculation of gain helps to understand the effects of amplification or reduction on the signal during transmission, which is crucial for evaluating system performance and characteristics. The extraction of phase information reveals the behavior of the signal at different frequencies, helps to analyze delay loss and system stability, and provides a basis for subsequent control and optimization.Step S1053: Record the frequency response characteristics and reconstruct the signal, determine the frequency range when the amplitude attenuates to a certain mark value (such as -3dB point) under the frequency response, help judge the bandwidth, the effective transmission range of the signal, etc.; record the frequency with the largest amplitude in the spectrum, and provide the strongest component of the signal in the frequency domain; perform signal reconstruction based on the gain and phase information obtained in the frequency domain by inverse fast Fourier transform (IFFT), and restore the time domain morphology of the original signal; compare and analyze the reconstructed signal with the reference signal; analyze the signal consistency, similarity and difference by comparing the reconstructed signal with the reference signal, and provide visualization for understanding the changes in the signal process. The calculation of the spectrum amplitude and the amplitude response analysis can describe the frequency characteristics of the signal and its influence in detail, as an important indicator of signal transmission efficiency; the signal reconstruction and comparative analysis process provides a means to verify the consistency of signal characteristics, can identify distortion, delay or loss in signal transmission, and help optimize and improve system design.

[0083] In summary, this embodiment performs the frequency response characteristic analysis of the reference signal in the above steps to help fully understand the time domain and frequency domain characteristics of the signal. By extracting and calculating important parameters such as the amplitude, phase, and gain of the signal, it can provide basic data support for the characteristic modeling of the electromagnetic disturbance excitation signal, which helps to achieve more efficient and reliable monitoring and control in practical applications.

[0084] Example 6: Figure 6 As shown, based on Example 1, the process of establishing a functional relationship between an electromagnetic disturbance excitation signal and a characteristic value provided by an embodiment of the present invention includes the following steps:

[0085] S108: using finite element software, importing a corresponding geometric model; the geometric model reflects the shape, size and mutual relationship of the structures of the components of the power system; dividing the geometric model into finite elements, and using a grid at the position where the excitation signal acts;

[0086] S109: Set boundary conditions, apply reference excitation signals in the geometric model, and simulate the forces or displacements of each component under real conditions; use a dynamic analysis solver to configure the parameters required in the calculation process, including total time, time step, solution accuracy, etc.; perform finite element analysis to calculate the response of the structure under specific excitation;

[0087] S110: Analyze the simulation results of the finite element analysis, extract the frequency response characteristics, perform Fourier transform on the obtained reference signal and response signal, and transform them from the time domain to the frequency domain to extract the frequency components; extract important eigenvalues ​​from the frequency spectrum, and establish a functional relationship between the excitation signal and the eigenvalues;

[0088] Among them, the functional relationship f(z)=ts;

[0089] In the formula, ts represents the characteristic value of each excitation signal, and z represents the excitation signal;

[0090] The working principle and beneficial effects of the above technical solution are as follows: In this embodiment, finite element software is first used to import the corresponding geometric model; the geometric model reflects the shape, size and mutual relationship of the structures of the various components of the power system; the geometric model is divided into finite elements, and a grid is used at the position where the excitation signal acts; secondly, boundary conditions are set, and a reference excitation signal is applied to the geometric model to simulate the force or displacement of each component under real conditions; a dynamic analysis solver is used to configure the parameters required in the calculation process, including the total time, time step, solution accuracy, etc.; finite element analysis is performed to calculate the response of the structure under specific excitation; finally, the simulation results of the finite element analysis are analyzed, the frequency response characteristics are extracted, and the obtained reference signal and response signal are Fourier transformed, and converted from the time domain to the frequency domain to extract the frequency component; important eigenvalues ​​are extracted from the spectrum, and a functional relationship between the excitation signal and the eigenvalue is established. Step S108 of the above scheme imports the geometric model and mesh division, uses finite element software to import the geometric model, ensures that the model accurately reflects the structural characteristics of the power system under study; divides the imported geometric model into finite elements, ensures that the mesh at the position where the excitation signal is applied is fine enough to capture complex dynamic behaviors and responses; accurate geometric representation: reflects the size, shape and relationship between real components, ensures the reliability of simulation results; by using denser meshes in specific areas, the accuracy of numerical analysis can be improved, the professionalism of dynamic analysis can be improved, and the foundation for subsequent response calculations can be laid. Step S109 applies boundary conditions and excitation signals, sets corresponding boundary conditions according to actual application scenarios to simulate the operating state (such as fixed, articulated, etc.) in a real environment; applies reference excitation signals in the geometric model to truly simulate the impact of electromagnetic disturbance on the system; uses a solver for dynamic analysis, and configures appropriate parameters, such as total time, time step, etc., so as to effectively capture dynamic responses. By applying appropriate excitation signals and boundary conditions, it is ensured that the finite element model can work under real electromagnetic disturbance conditions, thereby enhancing the practical significance of the analysis; the appropriate solver settings can optimize the calculation efficiency and result quality, so that the accuracy of subsequent analysis can be guaranteed. Step S110 frequency response characteristic extraction and eigenvalue establishment, the results of the finite element analysis are processed, the frequency response characteristics are extracted, and it is scientific and practical; the obtained reference signal and response signal are Fourier transformed, and they are converted from the time domain to the frequency domain to extract the frequency component; important eigenvalues ​​(ts) are extracted from the spectrum, and the functional relationship between the excitation signal and the eigenvalue is constructed (f(z)=ts); the importance of frequency response characteristics: understanding the response characteristics of the system at different frequencies helps to identify the dynamic characteristics and potential problems of the system; by extracting eigenvalues ​​to establish functional relationships, it not only provides a basis for quantitative analysis of the model, but also can be used to predict and optimize a certain state in the future.

[0091] In summary, each step of the entire process of this embodiment is an important part of establishing the relationship between the electromagnetic disturbance excitation signal and the eigenvalue function. Through this series of steps, a systematic method can be finally formed to scientifically analyze and solve the impact of electromagnetic disturbance on the dynamic system. This not only improves the understanding of the dynamic characteristics of the system, but also provides a strong theoretical basis and empirical support for subsequent optimization and design. Especially in engineering applications, more effective system protection and performance improvement can be achieved by adjusting the excitation signal or design.

[0092] Example 7: Figure 7 As shown, based on Example 1, the construction process of the whole vehicle electromagnetic environment simulation mathematical model provided by the embodiment of the present invention includes the following steps:

[0093] S201: Determine the structures of the power system electronic disturbance model, the vehicle geometry model, and the human body simulation model and their positions in the vehicle electromagnetic environment simulation mathematical model;

[0094] S202: importing the three-dimensional geometric model of the whole vehicle into the simulation software, partitioning the three-dimensional geometric model according to different materials and physical properties, and defining material properties; parameterizing the circuit model obtained by electronic disturbance modeling, and introducing it as a source into the overall three-dimensional geometric model; importing the human body simulation model including the placement position of the human body model to match the spatial layout inside the vehicle;

[0095] S203: Use the coupling function of the simulation tool to connect the electromagnetic field analysis with the mechanical analysis, set the force of the electromagnetic field on the vehicle structure, including the current, temperature change and vibration caused by the electromagnetic field; define the current density, induced electromotive force and the force exerted on the material by the electromagnetic field; set the biological effect of the electromagnetic field on the human body model, define the influence area and effect of the electric field and magnetic field on the biological tissue (such as current distribution and thermal effect); transfer the data of the electromagnetic field, mechanical stress or thermal distribution to each other through the preset interface; after the setting is completed, run the whole vehicle electromagnetic environment simulation mathematical model to obtain the response data of the system in different scenarios.

[0096] The working principle and beneficial effects of the above technical solution are as follows: In this embodiment, the structures of the power system electronic disturbance model, the whole vehicle geometric model, and the human body simulation model and their positions in the whole vehicle electromagnetic environment simulation mathematical model are first determined; secondly, the three-dimensional geometric model of the whole vehicle is imported into the simulation software, and the three-dimensional geometric model is partitioned according to different materials and physical properties, and the material properties are defined; the circuit model obtained by the electronic disturbance modeling is parameterized and introduced into the overall three-dimensional geometric model as a source; the human body simulation model including the placement position of the human body model is imported to match the spatial layout inside the vehicle; finally, the coupling function of the simulation tool is used to connect the electromagnetic field analysis with the mechanical analysis, and the electromagnetic field force on the vehicle structure is set, including the current, temperature change and vibration caused by the electromagnetic field; the current density, induced electromotive force and the force exerted on the material by the electromagnetic field are defined; the biological effect of the electromagnetic field on the human body model is set, and the influence area and effect of the electric field and magnetic field on the biological tissue (such as current distribution and thermal effect) are defined; the electromagnetic field, mechanical stress or thermal distribution data are mutually transmitted through a preset interface; after the setting is completed, the whole vehicle electromagnetic environment simulation mathematical model is run to obtain the response data of the system in different scenarios. Step S201 of the above scheme: structure and position determination, determine the specific structure of the electromagnetic disturbance model, geometric model and human body model, and lay the foundation for the subsequent model integration; ensure the reasonable layout of each model in the physical space, so as to facilitate the subsequent interaction and impact analysis. The completion of this stage indicates that the integration of models in different fields has a foundation, which can accurately characterize the overall performance of the vehicle in the electromagnetic environment; by defining the position of each model in the overall simulation, a systematic method is provided to enter the next step of detailed modeling, reducing the possibility of later simulation errors. Step S202 three-dimensional geometric model and parameter setting, import the three-dimensional geometric model of the whole vehicle into the simulation software, perform appropriate partitioning and define material properties, which can ensure the accuracy of electromagnetic analysis; parameterize and introduce the electronic disturbance model to form an actual power source that can be analyzed; match the position of the human body model to ensure that the analysis of biological effects has a realistic basis. The fine division of the three-dimensional geometric model and the assignment of material properties make the simulation more like the system in the real environment and improve the credibility of the analysis; ensure that effective calculations can be performed during the simulation process, form actual responses under complex electric and magnetic fields, and lay the foundation for subsequent multi-physical field coupling. Step S203 couples the analysis and operation simulation, combining the electromagnetic field with the mechanical analysis function to achieve dynamic calculation of the electromagnetic field's force on the vehicle structure, including current changes, temperature rise, and vibration response; analyzes the impact of the electromagnetic field on the human body model, including current distribution and thermal effects, taking into account the response of biological tissue; and transmits electromagnetic field, mechanical stress, and thermal distribution data in real time through a preset interface to achieve seamless information connection.Comprehensive consideration of electromagnetic and mechanical effects can provide a more comprehensive system performance and form a multi-dimensional evaluation of the vehicle under the influence of the electromagnetic environment. This analysis can identify the potential risks of electromagnetic interference to occupants and equipment during vehicle operation, providing data support for subsequent design optimization and safety assessment. The data after simulation operation provides a basis for further model verification and promotes continuous optimization and improvement.

[0097] In summary, each step in the entire construction process of this embodiment plays an important role in the overall construction of the electromagnetic environment simulation mathematical model of the whole vehicle. Through the complementary technical effects and significance, the ultimate goal is to achieve a comprehensive analysis of the operation behavior of the whole vehicle in the electromagnetic environment, which not only improves the electromagnetic compatibility of the system, but also helps to improve the safety, reliability and user experience of the whole vehicle.

[0098] Embodiment 8: Based on Embodiment 7, the process of constructing the power system electronic disturbance model provided in the embodiment of the present invention comprises the following steps:

[0099] Identify and define the boundaries of the power system for which the power system electronic disturbance model is required, and determine the operating characteristics of the power system;

[0100] The boundaries include motors, batteries, on-board chargers and DC / DC converters, as well as the switching frequency of motor controllers. The motors include type, torque / speed characteristics, rated voltage, efficiency, mechanical characteristics and structural parameters. The batteries include the voltage, power and quantity of single cells, the number of modules in the battery pack, the power supply voltage and power supply efficiency of the battery pack, the input power and output power of the on-board charger, and the input current and output current of the DC / DC converter.

[0101] Working characteristics include: system dynamic response time under frequent starting / stopping, acceleration / deceleration and stable operation conditions, overload signal characteristics, etc.

[0102] According to the working characteristics and the nature of electronic disturbance, a power system electronic disturbance model is constructed, and disturbance terms are introduced into the power system electronic disturbance model to represent the impact of electronic disturbance on the power system; for low-frequency working conditions, the electrical characteristics of the power system are analyzed, and a lumped parameter low-frequency circuit model is established; the model is subjected to dynamic response analysis to analyze the behavioral changes of the power system under different working conditions.

[0103] Integrate radiation, diffraction, scattering and coupling models to conduct in-depth analysis of power system electronic disturbance using numerical simulation tools, evaluate the impact of acoustic and electromagnetic noise sources, and their impact on power system performance;

[0104] Among them, antenna radiation model: such as antenna gain and directivity, to analyze the propagation characteristics of the signal; identify the time delay and signal attenuation caused by the radiation of the excitation signal, so as to correct the power system electronic disturbance model. Aperture radiation model: evaluate the impact of apertures on the propagation of electromagnetic waves, especially when the signal needs to be transmitted through small holes or gaps, considering the impact of edge effects and aperture size on the radiation pattern; diffraction and scattering model: use Fresnel diffraction and Rayleigh scattering models to analyze the behavior of signals near various objects (such as metal frames, insulators, etc.); adjust the system response model based on measured data and theoretical models to enhance the perception of potential interference sources; the introduction of transmission line coupling model, due to the enhanced energy coupling under high-frequency conditions, the use of transmission line coupling model can help evaluate emerging electromagnetic interference. Application of coupling model: by analyzing the impedance changes of the transmission line, taking into account factors such as poor grounding and reduced shielding effect, evaluate these effects on the high-frequency signal link; introduce transmission line model parameters in the power system electronic disturbance model to simulate the coupling effect under different working conditions.

[0105] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first identifies and defines the boundaries of the power system for which the power system electronic disturbance model needs to be established, and determines the working characteristics of the power system; secondly, according to the working characteristics and the properties of the electronic disturbance, a power system electronic disturbance model is constructed, and disturbance terms are introduced into the power system electronic disturbance model to represent the influence of the electronic disturbance on the power system; for low-frequency working conditions, the electrical characteristics of the power system are analyzed, and a lumped parameter low-frequency circuit model is established; the model is subjected to dynamic response analysis, and the behavior changes of the power system under different working conditions are analyzed; finally, radiation, diffraction, scattering and coupling models are integrated to analyze the electrical characteristics of the power system. Sub-disturbance is deeply analyzed using numerical simulation tools to evaluate the impact of acoustic and electromagnetic noise sources and their impact on the performance of the power system; the above scheme identifies and defines the boundaries and working characteristics of the power system, establishes the specific boundaries of each component in the model, such as motors, batteries, on-board chargers and DC / DC converters, etc., through the clear definition of the technical parameters of each component; determines the core elements that affect the performance of the power system and their interrelationships; identifies the dynamic response characteristics of the power system under different working conditions, including frequent starting / stopping, acceleration / deceleration and steady-state operation; evaluates the system's ability to withstand overload and determines the characteristics of the overload signal. This step lays the foundation for the construction of subsequent models. Through clear boundaries and working characteristics, subsequent electronic disturbance analysis can be carried out for specific systems and operating conditions, thereby achieving higher modeling accuracy; identifying and defining the working characteristics of the system helps to formulate targeted test plans and optimization strategies to improve the reliability and stability of the system. Construct a power system electronic disturbance model, introduce disturbance terms into the model, quantify the impact of electronic disturbance on the power system, and ensure that the model can reflect the electromagnetic interference effects encountered in actual work; for low-frequency working conditions, establish a lumped parameter low-frequency circuit model to help analyze and describe the electrical characteristics of the system; conduct dynamic response analysis, especially the behavior changes under different working conditions (such as starting, acceleration, steady state, etc.); this step enables the model to be more in line with real working conditions in practice, thus providing a basis for the subsequent dynamic response analysis; deeply understand the behavior changes of the system under electronic disturbance, ensure that the performance of the power system under high load and emergency conditions will not be significantly affected, and thus improve the system's anti-interference ability. Integrate radiation, diffraction, scattering and coupling models for in-depth analysis, comprehensively consider radiation, diffraction, scattering and coupling models, and form a comprehensive electronic disturbance analysis framework; use numerical simulation tools to conduct in-depth analysis of different sound and electromagnetic noise sources, and evaluate their impact on the performance of the power system; evaluate in detail the changes in the system dynamic characteristics caused by electromagnetic interference, and provide effective feedback basis for subsequent design optimization.This process, through comprehensive analysis of multiple influencing factors, enables a more comprehensive understanding of the impact of interference sources on the power system and provides theoretical support for its optimization; through in-depth simulation and analysis, the development team can more effectively identify and select appropriate power supplies and control systems to improve the robustness and performance of the entire power system.

[0106] In summary, the above steps of this embodiment have played an important role in clarifying the system boundary and working characteristics, constructing the disturbance model and its dynamic behavior analysis, and evaluating the comprehensive influencing factors. The significance of the whole process is to ensure the stability and reliability of the power system in the face of electronic disturbances, and to provide a scientific basis for the optimization and debugging of related designs. This can not only improve the overall performance of the power system, but also provide a solid foundation for subsequent applications and expansion.

[0107] Embodiment 9: Based on Embodiment 7, the process of constructing the full vehicle geometric model provided by the embodiment of the present invention comprises the following steps:

[0108] Obtain the design parameters and specific dimensional data of the vehicle, including the body shape, wheel position, chassis height and internal dimensions of the driving space (such as seats, instrument panel, roof height, etc.); obtain CAD drawings and reference models;

[0109] Select 3D modeling software for geometric modeling, generate the body geometry model based on the collected dimensional data, and model the internal structure of the driving space;

[0110] Use the meshing tool to select the structured mesh according to the requirements of electromagnetic field calculation and set the meshing parameters; discretize the three-dimensional geometric model of the whole vehicle to generate the mesh required for calculation. After completing the meshing, check the mesh quality indicators;

[0111] The divided grids are imported into the electromagnetic field analysis software for electromagnetic field simulation. Through simulation calculation, the accuracy and reliability of the three-dimensional geometric model of the whole vehicle are verified.

[0112] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first obtains the design parameters and specific dimensional data of the vehicle, including the body shape, wheel position, chassis height and internal dimensions of the driving space (such as seats, dashboard, roof height, etc.); obtains CAD drawings and reference models; secondly, selects 3D modeling software for geometric modeling, and generates a body shape geometric model based on the collected dimensional data; models the internal structure of the driving space; then uses a meshing tool to select a structured grid according to the requirements of electromagnetic field calculation, and sets the parameters for meshing; discretizes the 3D geometric model of the entire vehicle to generate the grid required for calculation, and after completing the meshing, checks the mesh quality indicators; finally, imports the divided grid into the electromagnetic field analysis software for electromagnetic field simulation, and verifies the accuracy and reliability of the 3D geometric model of the entire vehicle through simulation calculation. The above scheme obtains vehicle design parameters and dimensional data, and establishes the basic data set of the model by obtaining detailed information on the body shape, wheel position, chassis height and internal dimensions of the driving space; clarifies the physical scope and key structural elements of the model, and provides a clear direction for subsequent modeling; the accuracy of the data directly affects the authenticity of the model and subsequent calculation results, so it is crucial to collect comprehensive and accurate parameters; provide data support for efficient and accurate electromagnetic field analysis to ensure that the model conforms to the actual vehicle design. Obtain CAD drawings and reference models. Through CAD drawings and reference models, you can clearly understand the geometric structure and complex design of the vehicle; with the help of existing design files, you can build models faster and reduce errors and omissions; effectively use existing resources to improve modeling efficiency and ensure that the model matches the real vehicle design; provide reference for subsequent detail adjustments and optimizations to ensure the accuracy of the model. Choose 3D modeling software for geometric modeling. Choose appropriate software such as SolidWorks, CATIA, etc., and make full use of its powerful modeling functions to generate high-quality geometric models; use software functions for parametric modeling to improve the flexibility and efficiency of modeling; this step makes the modeling process more professional and standardized, reduces the errors that may be introduced by manual modeling, and improves the accuracy of the model; it lays a solid foundation for subsequent analysis and simulation. Model the internal structure of the driving space. Through the detailed modeling of the internal structure, the complete performance of the driving space during simulation is ensured; establish an accurate interior model, which is conducive to the detailed parameter setting in the subsequent electromagnetic field analysis; the accurate construction of the driving space is conducive to the subsequent electromagnetic and thermal analysis, affecting the overall vehicle performance evaluation; improve the realism of the model, make the simulation closer to the actual situation, and enhance the credibility of the simulation results.Use the meshing tool to select the structured mesh, select the mesh according to specific needs, and ensure that the type and size of the mesh are suitable for electromagnetic field calculation; standardize parameter settings: by setting reasonable meshing parameters, generate high-quality calculation meshes and improve calculation efficiency; reasonable meshing has a great impact on the accuracy of electromagnetic field simulation, ensuring the data validity of subsequent calculations; clear division methods can improve the use of computing resources and improve analysis efficiency. Discretize the three-dimensional geometric model of the whole vehicle, and convert the continuous model into a mesh suitable for numerical calculation through discretization; check the mesh quality indicator to ensure that it has no obvious defects, such as too large mesh units; discretization makes electromagnetic field analysis possible, ensuring that the model can be effectively used for numerical calculations; the improvement of mesh quality directly ensures the reliability and accuracy of simulation results, thereby affecting subsequent decisions. Import the divided mesh into the electromagnetic field analysis software, and import the mesh model into the analysis software to make electromagnetic field simulation feasible and obtain relevant analysis data; set the electromagnetic field calculation parameters through the software to ensure the accurate execution of the analysis. This process is the key to electromagnetic field analysis and realizes the transformation of the model from theory to practice; through simulation calculations, the electromagnetic interference problem of the vehicle can be evaluated and data support can be provided for optimized design. Verify the accuracy and reliability of the 3D geometric model of the entire vehicle, and verify the accuracy of the model and the rationality of the simulation results by comparing with experimental data or standard values; obtain feedback during verification to adjust and optimize the modeling and simulation process; ensuring the reliability of the model in practical applications is the ultimate goal of the entire modeling and simulation process, which helps to improve the design optimization level of electric vehicles in electromagnetics; through verification and optimization, the value of the model in practical applications is improved, ensuring the scientific nature of design decisions.

[0113] In summary, the above steps of this embodiment not only constitute the complete construction process of the vehicle geometry model, but also provide the necessary basis for the calculation and analysis of the electromagnetic field. Through the implementation of each step, the accuracy and practicality of the model can be ensured, the performance of electric vehicles in complex environments can be accurately evaluated, and an important basis can be provided for subsequent design optimization.

[0114] Embodiment 10: Based on Embodiment 7, the process of establishing a human body simulation model provided by the embodiment of the present invention comprises the following steps:

[0115] Determine the human body model standard to be used, including digital human body model or universal human body model; set the specific parameters of the human body model, such as height, weight, body shape, posture (driving or riding), etc.; define the electromagnetic properties of each part of the human body model (for example, tissue type, dielectric constant, etc.);

[0116] Select 3D modeling software and construct the geometric shape of the human body, including the head, torso and limbs, according to the selected standards and parameters;

[0117] Import the 3D mesh model of the entire vehicle and place the human body model at the corresponding position inside the vehicle (such as the driving position or the passenger position).

[0118] The working principle and beneficial effects of the above technical solution are as follows: This embodiment first determines the human model standard to be used, including a digital human model or a universal human model; sets specific parameters of the human model, such as height, weight, body shape, posture (driving or riding), etc.; defines the electromagnetic properties of each part of the human model (for example, tissue type, dielectric constant, etc.); secondly, selects a three-dimensional modeling software, and constructs the geometric shape of the human body, including the head, torso and limbs, etc., according to the selected standards and parameters; finally, imports the three-dimensional mesh model of the whole vehicle, and places the human body model in the corresponding position inside the vehicle (such as the driving position or the passenger position). The above scheme determines the human body model standard to be used, and selects the use of a digital human body model (such as SAM, DASY) or a universal human body model according to the relevant standards, thereby providing guidance for subsequent modeling, and the application of standard models ensures the consistency and comparability of the analysis; the selection of appropriate standards can ensure that the established human body model is scientific in terms of biophysical properties, and improve the application value of the model in simulation; different model standards can better reflect the characteristics of specific populations or scenarios, and help analyze health risks under specific conditions. Setting the specific parameters of the human body model enables the model to better reflect the physiological characteristics of the target population, making the simulation results more accurate and practical; the model in different postures can show the real sitting posture and riding comfort in the vehicle, providing a real basis for subsequent analysis. Define the electromagnetic characteristics of each part of the human body model. Different tissues have significant differences in the response to electromagnetic waves. Accurate electromagnetic characteristics help to truly simulate the performance of the human body in the electric field; reflecting the real biophysical properties in the model can improve the reliability of electromagnetic field calculation and specific absorption rate (SAR) analysis, and ensure the health and safety of occupants. Choosing 3D modeling software can improve modeling efficiency and accuracy, and use its powerful functions and features to efficiently create complex models; with flexibility, the modeling process can be adjusted according to needs to adapt to different simulation scenarios and goals. Importing the 3D mesh model of the whole vehicle to realize the physical combination of the vehicle model and the human body model helps to simulate the real response of the human body in the electromagnetic environment; ensuring that the subsequent electromagnetic field analysis is carried out in an accurate environment, so that the simulation results are closer to the actual situation, thereby improving the application value of the model.

[0119] In summary, this embodiment not only ensures the scientificity and accuracy of the human body simulation model through the implementation of the above steps one by one, but also lays a solid foundation for the subsequent electromagnetic field analysis. Each step plays a vital role in the entire modeling and analysis process, providing necessary support for the final design optimization, occupant safety assessment and electric vehicle electromagnetic compatibility research.

[0120] Embodiment 11: Based on Embodiment 1 to Embodiment 9, the application of the electromagnetic interference model based on the whole vehicle electromagnetic environment simulation provided by the embodiment of the present invention calculates the electromagnetic field distribution of the electric vehicle space and verifies the accuracy of the simulation mathematical model; comprising the following steps:

[0121] Formulate a test plan based on the actual road driving conditions of electric vehicles; select a certain electric vehicle as the test vehicle; establish a three-dimensional network geometry model of the entire vehicle based on the actual size of the test vehicle body;

[0122] After the three-dimensional mesh geometric model of the whole vehicle is built, the electromagnetic disturbance model is simulated and added at the actual position of the power system. The parameters are consistent with the actual vehicle (such as the battery voltage is 316.8V, the operating frequency is 1hz-400khz, etc.), simulating the electromagnetic field generated by the power system when it is working; dividing the grid, the density of the grid division directly affects the correctness and efficiency of the simulation calculation, and the appropriate grid density is calculated according to the characteristic frequency of the vehicle power system disturbance to perform discretization simulation calculation on the model; ⑥ Solve the Maxwell equations of the whole vehicle electromagnetic environment simulation mathematical model, and use the frequency domain moment method (MOM) to calculate the theoretical distribution value of the electromagnetic field generated by the power system in the vehicle space;

[0123] The industry implementation standard: JASO TP-13002 (2013) was selected as the reference standard for the test. Precision electromagnetic field measurement probes were used, and FFT analysis function was adopted. The operating frequency covered the characteristic frequency range of power system disturbance (1Hz-400kHz). The spectrum measurement of electric field and magnetic field was carried out simultaneously in each axis. The time-varying electromagnetic field was measured using the time-domain convolution weighted peak evaluation mode. The actual distribution value of the electromagnetic field in the selected test vehicle was measured when simulating actual road driving conditions.

[0124] Compare the simulation calculation results of the electromagnetic field radiation value of the electric vehicle power system using the frequency domain moment method (MOM) with the actual vehicle operation measurement results using the time domain convolution weighted peak method; analyze the characteristics of the spatial electromagnetic field distribution of electric vehicles under different operating conditions (vehicle start-up, stable operation, and braking status, etc.), analyze the causes of the deviation between theory and test, and correct the results to improve the applicability and accuracy of the system mathematical model.

[0125] The working principle and beneficial effects of the above technical solution are as follows: This embodiment formulates a test plan based on the actual road driving conditions of electric vehicles, establishes a comprehensive test framework, ensures that the experiment can cover the electromagnetic interference of electric vehicles under various actual driving conditions; ensures that the test results are representative, can reflect the electromagnetic field characteristics of electric vehicles in different scenarios, and provide real data support for subsequent model verification. Select a certain electric vehicle as the test vehicle to ensure that the selected vehicle can be an effective representative of the experimental results; make the test results have wide applicability, facilitate the promotion and application of the results, and support the electromagnetic compatibility research of this model or similar models. According to the actual size of the test vehicle body, establish a three-dimensional network geometric model of the whole vehicle, create a high-precision three-dimensional geometric model, ensure that it accurately reflects the design of a typical electric vehicle in shape and structure; the complete geometric model provides the necessary basis for subsequent electromagnetic field analysis, and ensures the accuracy and reliability of the simulation results. Simulate and add an electromagnetic disturbance model at the actual position of the power system, accurately simulate the electromagnetic disturbance of the electric vehicle power system, and set the parameters consistent with the actual vehicle to provide a model of a real electromagnetic radiation source; so that the simulation model can reflect the electromagnetic interference generated by the electric vehicle under actual operation, and provide a real basis for subsequent analysis. Divide the grid, according to the electromagnetic radiation characteristics of different frequencies, reasonably divide the grid density of the calculation model, improve the effectiveness and accuracy of the calculation; high-quality grid division directly affects the calculation efficiency and the accuracy of the results, making the simulation more precise and accurate. Solve the Maxwell equations of the whole vehicle electromagnetic environment simulation mathematical model, use the frequency domain moment method (MOM) to solve the electromagnetic field equations, and calculate the theoretical distribution of the electromagnetic field generated by the electric vehicle power system; this step provides a theoretical basis for the simulation of the electromagnetic field and provides a quantitative analysis basis for the subsequent comparison and verification with experimental measurement results. Select the industry implementation standard and test it according to the JASOTP-13002 (2013) standard to ensure that the test process meets regulatory requirements and has an international comparison basis; the standardized test process can improve the credibility and comparability of the test results and provide a basis for industry recognition. Use precision electromagnetic field measurement probes, high-precision measurement probes and FFT analysis technology to conduct comprehensive and detailed measurements of the electromagnetic field, covering a specific frequency range; the actual measurement data can verify the accuracy of the theoretical model calculation and provide a strong basis for verifying the simulation model. Compare the simulation results with the actual measurement results, compare the electromagnetic field distribution calculated by the frequency domain moment method with the actual measurement results, and analyze the consistency and deviation between the two. Through this comparative analysis, potential problems in the model can be identified and corrected, and the accuracy and applicability of the model can be improved. Study the spatial electromagnetic field distribution characteristics under different operating conditions, clarify the characteristic changes of the electromagnetic field under different operating conditions (such as starting, stable driving, braking, etc.) and the deviation between theoretical and actual measurements; this in-depth analysis will provide important guidance for the electromagnetic compatibility design of electric vehicles and ensure their safety and reliability under different working conditions.

[0126] In summary, this embodiment forms a complete set of electromagnetic interference models and their application process for electromagnetic field analysis of electric vehicles through the implementation of the above steps. This process can not only help verify and optimize the accuracy of the electromagnetic environment simulation mathematical model, but also help guide electric vehicles to improve electromagnetic compatibility during the design and manufacturing stages. This research provides important support for the safety, reliability and market competitiveness of electric vehicles, and has important academic value and practical application prospects.

[0127] Embodiment 12: Based on Embodiments 1 to 9, the application of the electromagnetic interference model based on the whole vehicle electromagnetic environment simulation provided by the embodiment of the present invention to the design of the electromagnetic compatibility (EMC) of the electric vehicle power system includes the following steps:

[0128] Evaluate the electromagnetic safety of electric vehicle power systems, including: the distribution law and trend of electromagnetic radiation field strength in the driving space of electric vehicles; introduce the calculation of the human electromagnetic absorption rate SAR value into the evaluation of electromagnetic radiation of electric vehicles to the human body, and calculate the intensity of electromagnetic radiation exposed to the human body in the electromagnetic environment inside the vehicle; evaluate whether the electromagnetic radiation inside the vehicle during operation meets the human safety standards, and formulate the test methods and standards for electromagnetic protection of the human body in the vehicle electromagnetic field;

[0129] Secondly, the design of electromagnetic compatibility (EMC) of electric vehicle power system includes: motor grounding design, grounding of various control signals and isolation of high and low voltage components; shielding design of alternating electromagnetic field between motor rotor and electronics and shielding design of transmission cable; filter layout between motor controller and sensor; electromagnetic wave absorption design of battery pack material; suppression of transient noise of various switching devices of motor controller, on-board charger and DC / DC conversion module; PCB grounding, wiring, decoupling and bypass design of various control circuit boards.

[0130] The working principle and beneficial effects of the above technical solution are as follows: This embodiment evaluates the electromagnetic safety of the electric vehicle power system, which is crucial to optimizing the design of electric vehicles and improving the safety of drivers and passengers. Understanding the spatial distribution of electromagnetic radiation can provide a reliable basis for subsequent improvement measures to ensure the health and safety of passengers during driving; the SAR value is a widely accepted standard for evaluating the impact of electromagnetic waves on the human body. This assessment will help protect the physical health of passengers and ensure that the car meets relevant safety standards; the assessment can ensure that electric vehicles have no adverse effects on consumers during the commercialization process, enhance market trust, and provide a basis for vehicle certification; this standardization process will provide a scientific and standardized basis for the electromagnetic radiation assessment of different models, so that the entire industry has more quantitative standards for electromagnetic interference and radiation assessment, which will help improve the overall safety level of electric vehicles. The design of electromagnetic compatibility (EMC) of electric vehicle power system can reduce the interference of electromagnetic radiation generated by motors or high-voltage systems on other electronic components, ensure the normal operation of various components of the vehicle, and improve the stability and reliability of the whole vehicle; the shielding design can significantly reduce the impact of electromagnetic radiation on drivers and passengers, while ensuring the integrity and reliability of control signals during transmission; ensure the stable operation of sensors and controllers, prevent erroneous signals caused by electromagnetic interference, thereby improving the vehicle's handling and safety; improve battery safety and the quality of the electromagnetic environment in the vehicle, protect the safety of drivers and passengers, and reduce electromagnetic radiation that affects the vehicle's electronic equipment; the switching devices of the controller, on-board charger and DC / DC conversion module can suppress transient noise to effectively reduce electromagnetic interference; reduce the impact of transient noise on vehicle performance, and ensure that the electric system of electric vehicles can work reliably and stably under different working conditions; enhance the electromagnetic compatibility of electric vehicle electronic systems, improve their anti-interference ability and overall performance, and ensure the long-term stability and operational reliability of the system.

[0131] In summary, through the implementation of the above technical measures in this embodiment, electric vehicles will meet higher standards in terms of electromagnetic safety and electromagnetic compatibility. This can not only reduce the impact of electromagnetic radiation on drivers and passengers, ensure that there is no potential threat to health in the daily use of electric vehicles, but also improve the performance and safety of the entire vehicle through optimized design. This series of measures has laid a good foundation for the future research and development, production and marketing of electric vehicles, and provided direction for the industry to formulate corresponding electromagnetic compatibility test standards and evaluation specifications. In terms of application, the results of electromagnetic safety assessment can be used to guide the design, manufacture and use of electric vehicle power systems. For example, the switching frequency and layout of power electronic devices can be optimized according to the evaluation results to reduce the level of electromagnetic radiation; or the electromagnetic safety of the driving space can be improved by improving the electromagnetic shielding measures of the vehicle.

[0132] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention belong to the scope of equivalent technologies of the present invention, the present invention is also intended to include these modifications and variations.

Claims

1. A method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation, characterized in that: The following steps are involved: Obtain the electromagnetic disturbance excitation signal source of the electric vehicle, analyze the bandwidth characteristics, obtain the spectrum characteristics of the electromagnetic disturbance excitation signal, and then extract the characteristic value of the electromagnetic disturbance excitation signal; establish the functional relationship between the electromagnetic disturbance excitation signal and the characteristic value; Construct a whole vehicle electromagnetic environment simulation mathematical model consisting of a power system electronic disturbance model, a full vehicle three-dimensional mesh geometric model, and a human body simulation model to analyze the frequency response relationship of the power system under electromagnetic disturbance excitation; The whole vehicle electromagnetic environment simulation mathematical model is used to calculate the spatial electromagnetic field distribution of electric vehicles, and the measurement results of the whole vehicle electromagnetic environment simulation mathematical model are verified and evaluated.

2. The method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation according to claim 1, characterized in that: The process of analyzing bandwidth characteristics includes the following steps: Determine the source of the electromagnetic disturbance excitation signal to be analyzed, and use a spectrum analyzer to capture the spectrum characteristics of the electromagnetic disturbance excitation signal; collect the electromagnetic disturbance excitation signal under different speeds, load conditions or switching frequencies and different working conditions, and record and store the captured electromagnetic disturbance excitation signal waveform; The time domain signal of the electromagnetic disturbance excitation signal is converted by using the fast Fourier transform to obtain the frequency domain representation of the electromagnetic disturbance excitation signal, and a set of complex numbers is output at the same time, representing the amplitude and phase of each frequency component; the spectrum, i.e. the amplitude information of each frequency in the time signal, is obtained by calculating the amplitude of the complex output, the frequency axis is established, the spectrum diagram is drawn, the frequency components are identified in the spectrum diagram, and the prominent peak and frequency range are obtained; According to the spectrum diagram, the bandwidth of the electromagnetic disturbance excitation signal is defined, and the energy distribution and attenuation characteristics of the electromagnetic disturbance excitation signal within the frequency range are analyzed.

3. The method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation according to claim 1, characterized in that: The process of extracting the characteristic value of the electromagnetic disturbance excitation signal includes the following steps: Each electromagnetic disturbance excitation signal source is placed in a simulation test platform of a power system to simulate the actual operating state of various speeds, loads and environmental conditions; sensors are arranged on each electromagnetic disturbance excitation signal source to record the electromagnetic disturbance excitation signal of each part under different working conditions in real time; Determine a standard reference signal under a certain working condition, analyze the frequency response characteristics of the reference signal, obtain the gain and phase changes at different frequency points, and the corresponding time domain characteristics; extract the characteristic value from the time domain signal; calculate the bandwidth width and amplitude of the time domain signal, reconstruct the time domain signal according to the characteristic value, and compare it with the reference signal; Extract the peak value and its peak frequency and corresponding peak time in the frequency domain signal, calculate the phase spectrum, and obtain the phase information at each frequency; extract the characteristic value from the phase spectrum; Based on the selected reference signal, its phase spectrum is defined as the comparison benchmark, and the phase spectrum of the electromagnetic disturbance excitation signal under different working conditions is differentially processed with the reference phase spectrum. The data in the phase spectrum is compared point by point to generate a new spectrum, which represents the difference between the two phase spectra at each frequency point. The collected differential phase spectrum will be used in the establishment of the electromagnetic disturbance model to quantify the difference between the actual electromagnetic disturbance excitation signal and the reference signal.

4. The method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation according to claim 3, characterized in that: Obtain phase information at each frequency, including the phase of zero frequency, DC component, and phase delay of each frequency component.

5. The method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation according to claim 3, characterized in that: Extract eigenvalues ​​from the phase spectrum, including minimum phase frequency and phase delay.

6. The method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation according to claim 3, characterized in that: The construction process of the simulation test platform includes the following steps: Identify the working conditions that need to be simulated and the types of electromagnetic disturbances that need to be tested, select the motor, transmission and load equipment, and select the electromagnetic interference source components to generate different types of electromagnetic disturbance signals; select current sensors, vibration sensors and voltage sensors; equip data acquisition cards and computers for real-time monitoring, recording and processing of experimental data; Build the physical structure of the simulation test platform, including fixing the motor, transmission and load equipment; arrange sensors to capture the electromagnetic disturbance signals of related components; connect various components according to the electrical drawings, including the connection between the motor and the power supply, the connection of the load, and the connection between the sensor and the data acquisition system; install the software on the data acquisition system and configure the parameters to read the sensor signals; Carry out preliminary debugging, check whether the connection is operating normally, and calibrate the sensor; for different operating conditions, clarify the speed, load and environmental parameter settings under each condition, prepare execution steps, data recording tables and analysis methods, record electromagnetic disturbance excitation signals in real time, store the collected data and perform preliminary analysis to identify signal characteristics.

7. The method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation according to claim 3, characterized in that: The process of analyzing the frequency response characteristics of the reference signal includes the following steps: The maximum amplitude value, the root mean square value and the zero crossing rate reflecting the amplitude of the reference signal are calculated; the root mean square value is used to represent the effective value of the reference signal, and the zero crossing rate calculates the frequency of the zero crossing point in the reference signal; the reference signal is subjected to a fast Fourier transform to convert the reference signal from the time domain to the frequency domain; The ratio of the input signal to the output signal of the reference signal is calculated to obtain the gain calculation result of the reference signal, and the phase variation characteristics of the reference signal are obtained by extracting the phase of each frequency point; Calculate the amplitude of the reference signal spectrum, determine the frequency range where the amplitude decays to a certain value under the frequency response, and record the value with the largest amplitude in the spectrum; use the inverse fast Fourier transform to convert the frequency domain signal back to the time domain, and reconstruct the signal using the frequency response characteristics obtained from the frequency domain; compare with the reference signal: compare the reconstructed signal with the initial reference signal, and analyze the consistency, similarity, or difference of the signal to identify any performance changes or distortions.

8. The method for constructing an electromagnetic interference model based on vehicle electromagnetic environment simulation according to claim 1, characterized in that: The process of establishing the functional relationship between the electromagnetic disturbance excitation signal and the characteristic value includes the following steps: Use finite element software to import the corresponding geometric model; the geometric model reflects the shape, size and relationship of the structure of each component of the power system; divide the geometric model into finite elements and use grids at the position where the excitation signal is applied; Set boundary conditions and apply reference excitation signals to the geometric model to simulate the forces or displacements that each component would experience under real conditions; use a dynamic analysis solver to configure the parameters required for the calculation process; perform finite element analysis to calculate the response of the structure under specific excitation; The simulation results of the finite element analysis are analyzed to extract the frequency response characteristics. The obtained reference signal and response signal are Fourier transformed from the time domain to the frequency domain to extract the frequency components. Important eigenvalues ​​are extracted from the spectrum, and the functional relationship between the excitation signal and the eigenvalue is established.

9. An application of an electromagnetic interference model in the calculation of the spatial electromagnetic field distribution of electric vehicles, characterized in that: The electromagnetic interference model is constructed by the electromagnetic interference model construction method based on whole vehicle electromagnetic environment simulation as described in any one of claims 1 to 8.

10. An application of an electromagnetic interference model in the design of electromagnetic compatibility of electric vehicle power system, characterized in that: The electromagnetic interference model is constructed by the electromagnetic interference model construction method based on whole vehicle electromagnetic environment simulation as described in any one of claims 1 to 8.

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