New energy automobile radiation emission resonance diagnosis method based on all-in-one high-voltage system

Abstract

According to the new energy automobile radiation emission resonance diagnosis method based on the all-in-one high-voltage system, real automobile experiment test data and modeling in a simulation environment are organically combined, and emission radiation resonance generation mechanisms and related distribution parameters corresponding to different high-voltage system structures under different working conditions can be subjected to real-time real-time real-time real-time real-time real-time real-time real-time real-time real-time real-time real-time real-time real-time real-time simulation; complete and deep simulation modeling is realized, and the radiation emission characteristics of the whole vehicle can be described and reproduced more accurately through verification of actually measured resonance data. A simulation model which is verified to be effective is used for carrying out multi-term quantitative discrimination on a resonance mechanism, so that a more targeted suppression strategy can be made and implemented, and the electromagnetic compatibility problem can be solved more efficiently from a design end.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic compatibility testing and optimization technology for new energy vehicles, specifically relating to a diagnostic method for radiated emission resonance in new energy vehicles originating from multi-in-one high-voltage systems. Background Technology

[0002] As research on the electromagnetic compatibility of vehicles deepens in the new energy vehicle industry, it has become increasingly clear that actual electromagnetic radiation emissions exceeding standards do not always manifest as a full-band increase. Instead, sharp peaks often appear at specific resonant points within the 150kHz to 30MHz frequency range, primarily caused by the highly integrated "all-in-one" high-voltage electric drive system in vehicles. Existing testing and optimization techniques for radiated emissions can be broadly categorized into two approaches: one is an experimental method that uses test data to pinpoint exceeding frequency points and analyzes the impact of key factors such as vehicle speed, high-voltage cables, and battery placement on the vehicle's radiated emissions. The drawback of this approach is its over-reliance on physical prototypes and the quality of measured data, which hinders effective implementation in the early stages, thus affecting the timely detection and resolution of problems. Another type is achieved through modeling and simulation. Although it has certain accuracy advantages compared to the previous method, most existing models still remain at the level of phenomenon description or local parameter design. They do not delve deeply into the physical mechanism of the formation of specific resonant frequencies, nor can they systematically reveal the inherent coupling mechanism between the resonant phenomenon and circuit parameters and structural layout. They cannot meet the requirements for dealing with complex problems such as multi-path coupling effects and distributed parameter characterization. Summary of the Invention

[0003] In view of this, and in response to the technical problems existing in this field, the present invention provides a diagnostic method for radiated emission resonance in new energy vehicles originating from an all-in-one high-voltage system, specifically including the following steps:

[0004] Step 1: Load the vehicle under test conditions in the experimental environment and conduct whole vehicle radiated emission test. Identify and record the corresponding frequency and amplitude of each radiated emission resonant point in the 150kHz to 30MHz frequency band. Then, keep the same test conditions and use an RF current probe clamped to the high voltage positive and negative cables to collect the frequency domain data of the common mode noise current flowing through the cables.

[0005] Step 2: Based on the vehicle's computer-aided design (CAD) data, a simplified geometric model is established using 3D modeling software, including the vehicle body metal structure, high-voltage component housing, high-voltage cables and their paths. The simplified geometric model is then imported into 3D electromagnetic simulation software, and a corresponding parametric model is established based on the structure and materials of the high-voltage cables to calculate the distribution parameters of the high-voltage cables in a wide frequency band.

[0006] Step 3: Use an impedance analyzer to measure the impedance-frequency curves of each key port of the high-voltage system to the vehicle body; on this basis, use the circuit simulator of the simulation software to establish a lumped parameter equivalent circuit so that it can accurately fit the impedance-frequency curve; then set the lumped parameter equivalent circuit as a load at the corresponding port of the three-dimensional electromagnetic model of the high-voltage cable to characterize the frequency-varying impedance characteristics of the common-mode current loop.

[0007] Step 4: Use the common-mode noise current frequency domain data collected in Step 1 as an excitation source and apply it to the corresponding port of the three-dimensional electromagnetic model of the high-voltage cable; set up a virtual field strength probe in the simulation environment to simulate the test antenna and calculate the virtual radiated emission field strength of the whole vehicle.

[0008] Step 5: Compare the simulated radiated emission spectrum of the whole vehicle obtained through simulation with the radiated emission related data obtained in Step 1, and evaluate the degree of matching between the simulation results and the measured frequencies and amplitudes of each radiated emission resonant point, thereby verifying the effectiveness of the simulation model.

[0009] Step 6: Use the validated simulation model for quantitative analysis to determine the causes of different emission and radiation resonance points.

[0010] Furthermore, in step one, an anechoic chamber or an open field is used as the experimental environment, and actual vehicle testing is carried out in accordance with the GB / T18387-2017 standard.

[0011] Furthermore, in step two, CATIA or Hyper Mesh 3D modeling software is used to establish simplified geometric models; CST Studio Suite is used for 3D electromagnetic simulation.

[0012] Furthermore, the parameterized model established in step two is specifically used to calculate distributed parameters, including at least parasitic inductance and parasitic capacitance.

[0013] Furthermore, the key ports for analysis and measurement in step three include at least the all-in-one controller and the power battery interface.

[0014] Furthermore, step six specifically distinguishes and quantifies the resonant modes dominated by different physical sources through the following quantitative analysis:

[0015] ① Cable structure resonance identification: The parasitic inductance and capacitance parameters in the parameterized model of the high-voltage cable are extracted by simulation software, and the series resonant frequency caused by these parameters is calculated. If the frequency calculation result is highly consistent with the measured resonant point, it can be determined that the resonance is mainly caused by the distributed parameter resonance caused by the structural parameters of the high-voltage cable itself.

[0016] ② Comparative simulation analysis using the port impedance replacement method: Specifically, the measured fitted impedance circuit of a key port (such as a multi-port) in the three-dimensional electromagnetic model is replaced with an ideal resistor with a constant impedance value in the corresponding frequency band, while keeping all other parameters of the model unchanged, and the simulation is run again; by comparing the frequency shift and amplitude change of the resonant point before and after the replacement, the contribution of the parasitic parameters of the port's impedance to ground to the resonance is evaluated, thereby determining whether the corresponding resonant point is dominated by the local resonance of the port.

[0017] The radiated emission resonance diagnostic method for new energy vehicles, derived from an all-in-one high-voltage system, provided by this invention, organically combines real-vehicle test data with modeling in a simulation environment. This enables relatively complete and in-depth simulation modeling of the emission and radiated resonance generation mechanisms and related distribution parameters under different operating conditions and for different high-voltage system structures. Verification with measured resonance data allows for a more accurate description and reproduction of the vehicle's radiated emission characteristics. Utilizing a validated simulation model to quantitatively identify multiple resonance mechanisms helps in developing and implementing more targeted suppression strategies, thus solving electromagnetic compatibility issues more efficiently from the design stage. Attached Figure Description

[0018] Figure 1 A flowchart of the method provided by the present invention;

[0019] Figure 2 A real vehicle radiated emission test platform built in an anechoic chamber environment;

[0020] Figure 3 A simplified geometric model was created for the vehicle's high-voltage system;

[0021] Figure 4 This is the electromagnetic model format established for the critical ports of high-voltage cables;

[0022] Figure 5 This describes the setup method for simulating test antennas in a simulation environment.

[0023] Figure 6 This is a verification result of the simulation modeling effect in an example of the present invention. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The present invention provides a diagnostic method for radiated emission resonance in new energy vehicles derived from multi-in-one high-voltage systems, such as... Figure 1 As shown, the specific steps include:

[0026] Step 1: Load the vehicle under test conditions in the experimental environment and conduct whole vehicle radiated emission test. Identify and record the corresponding frequency and amplitude of each radiated emission resonant point in the 150kHz to 30MHz frequency band. Then, keep the same test conditions and use an RF current probe clamped to the high voltage positive and negative cables to collect the frequency domain data of the common mode noise current flowing through the cables.

[0027] Step 2: Based on the vehicle's computer-aided design (CAD) data, a simplified geometric model is established using 3D modeling software, including the vehicle body metal structure, high-voltage component housing, high-voltage cables and their paths. The simplified geometric model is then imported into 3D electromagnetic simulation software, and a corresponding parametric model is established based on the structure and materials of the high-voltage cables to calculate the distribution parameters of the high-voltage cables in a wide frequency band.

[0028] Step 3: Use an impedance analyzer to measure the impedance-frequency curves of each key port of the high-voltage system to the vehicle body; on this basis, use the circuit simulator of the simulation software to establish a lumped parameter equivalent circuit so that it can accurately fit the impedance-frequency curve; then set the lumped parameter equivalent circuit as a load at the corresponding port of the three-dimensional electromagnetic model of the high-voltage cable to characterize the frequency-varying impedance characteristics of the common-mode current loop.

[0029] Step 4: Use the common-mode noise current frequency domain data collected in Step 1 as an excitation source and apply it to the corresponding port of the three-dimensional electromagnetic model of the high-voltage cable; set up a virtual field strength probe in the simulation environment to simulate the test antenna and calculate the virtual radiated emission field strength of the whole vehicle.

[0030] Step 5: Compare the simulated radiated emission spectrum of the whole vehicle obtained through simulation with the radiated emission related data obtained in Step 1, and evaluate the degree of matching between the simulation results and the measured frequencies and amplitudes of each radiated emission resonant point, thereby verifying the effectiveness of the simulation model.

[0031] Step 6: Use the validated simulation model for quantitative analysis to determine the causes of different emission and radiation resonance points.

[0032] In a preferred embodiment of the present invention, step one specifically employs the following method: Figure 2 The anechoic chamber or open field shown is used as the experimental environment, and real vehicle tests are carried out in accordance with the GB / T 18387-2017 standard.

[0033] In a preferred embodiment of the present invention, step two specifically employs CATIA or Hyper Mesh 3D modeling software to establish simplified geometric models, such as... Figure 3 As shown, Figure 3 (a) and Figure 3 (c) The original vehicle body structure and high-pressure system are shown separately. Figure 3 (b) and Figure 3 (d) are the simplified model forms respectively; the three-dimensional electromagnetic simulation software used is CSTStudio Suite.

[0034] In a preferred embodiment of the present invention, the parameterized model established in step two is specifically used to calculate distributed parameters including at least parasitic inductance and parasitic capacitance.

[0035] In a preferred embodiment of the present invention, the key ports for analysis and measurement in step three include at least an all-in-one controller and a power battery interface.

[0036] Figure 4 The diagram illustrates the specific form of constructing an RLC lumped-parameter equivalent circuit and assigning it as a load to the corresponding port of a three-dimensional electromagnetic model of a high-voltage cable. After applying an excitation source based on measured data, it is possible to utilize, for example... Figure 5 The virtual antenna setup shown is used to calculate the simulated spectrum of the vehicle's radiated emissions.

[0037] In a preferred embodiment of the present invention, step six specifically involves performing the following quantitative analysis to accurately distinguish and quantify the resonance modes dominated by different physical sources:

[0038] ① Cable structure resonance identification: The parasitic inductance and capacitance parameters in the parameterized model of the high-voltage cable are extracted by simulation software, and the series resonant frequency caused by these parameters is calculated. If the frequency calculation result is highly consistent with the measured resonant point, it can be determined that the resonance is mainly caused by the distributed parameter resonance caused by the structural parameters of the high-voltage cable itself.

[0039] ② Comparative simulation analysis using the port impedance replacement method: Specifically, the measured fitted impedance circuit of a key port (such as a multi-port) in the three-dimensional electromagnetic model is replaced with an ideal resistor with a constant impedance value in the corresponding frequency band, while keeping all other parameters of the model unchanged, and the simulation is run again; by comparing the frequency shift and amplitude change of the resonant point before and after the replacement, the contribution of the parasitic parameters of the port's impedance to ground to the resonance is evaluated, thereby determining whether the corresponding resonant point is dominated by the local resonance of the port.

[0040] In a specific example based on the present invention, the simulation results are compared with real vehicle test data, such as... Figure 6 As shown, the simulated curves at key resonant points such as 14.2MHz and 25.6MHz show a high degree of agreement between the center frequency and amplitude and the measured data, verifying the accuracy of the model in reproducing the real radiated emission characteristics in the key frequency band and proving that the method can provide a reliable basis for subsequent mechanistic analysis.

[0041] It should be understood that the sequence number of each step in the embodiments of the present invention does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A diagnostic method for radiated emission resonance in new energy vehicles derived from an all-in-one high-voltage system, characterized in that: Specifically, the following steps are included: Step 1: Load the vehicle under test conditions in the experimental environment and conduct whole vehicle radiated emission test. Identify and record the corresponding frequency and amplitude of each radiated emission resonant point in the 150kHz to 30MHz frequency band. Then, keep the same test conditions and use an RF current probe clamped to the high voltage positive and negative cables to collect the frequency domain data of the common mode noise current flowing through the cables. Step 2: Based on the vehicle's computer-aided design data, a simplified geometric model is established using 3D modeling software, including the vehicle body metal structure, high-voltage component housing, high-voltage cables and their paths. The simplified geometric model is then imported into 3D electromagnetic simulation software, and a corresponding parametric model is established based on the structure and materials of the high-voltage cables to calculate the distribution parameters of the high-voltage cables in a wide frequency band. Step 3: Use an impedance analyzer to measure the impedance-frequency curves of each key port of the high-voltage system to the vehicle body; on this basis, use the circuit simulator of the simulation software to establish a lumped parameter equivalent circuit so that it can accurately fit the impedance-frequency curve; then set the lumped parameter equivalent circuit as a load at the corresponding port of the three-dimensional electromagnetic model of the high-voltage cable to characterize the frequency-varying impedance characteristics of the common-mode current loop. Step 4: Use the common-mode noise current frequency domain data collected in Step 1 as an excitation source and apply it to the corresponding port of the three-dimensional electromagnetic model of the high-voltage cable; set up a virtual field strength probe in the simulation environment to simulate the test antenna and calculate the virtual radiated emission field strength of the whole vehicle. Step 5: Compare the simulated radiated emission spectrum of the whole vehicle obtained through simulation with the radiated emission related data obtained in Step 1, and evaluate the degree of matching between the simulation results and the measured frequencies and amplitudes of each radiated emission resonant point, thereby verifying the effectiveness of the simulation model. Step 6: Use the validated simulation model for quantitative analysis to determine the causes of different emission and radiation resonance points.

2. The method as described in claim 1, characterized in that: In step one, an anechoic chamber or an open field is used as the experimental environment, and actual vehicle testing is carried out in accordance with the GB / T 18387-2017 standard.

3. The method as described in claim 1, characterized in that: In step two, CATIA or Hyper Mesh 3D modeling software is used to create simplified geometric models; CST Studio Suite is used for 3D electromagnetic simulation.

4. The method as described in claim 1, characterized in that: The parameterized model established in step two is specifically used to calculate distributed parameters, including at least parasitic inductance and parasitic capacitance.

5. The method as described in claim 1, characterized in that: The key ports for analysis and measurement in step three include at least the all-in-one controller and the power battery interface.

6. The method as described in claim 1, characterized in that: Step six specifically involves the following quantitative analysis to precisely distinguish and quantify the resonant modes dominated by different physical sources: ① Cable structure resonance identification: The parasitic inductance and capacitance parameters in the parameterized model of the high-voltage cable are extracted by simulation software, and the series resonant frequency caused by these parameters is calculated. If the frequency calculation result is highly consistent with the measured resonant point, it can be determined that the resonance is mainly caused by the distributed parameter resonance caused by the structural parameters of the high-voltage cable itself. ② Comparative simulation analysis using the port impedance replacement method: Specifically, the measured fitted impedance circuit of a key port in the three-dimensional electromagnetic model is replaced with an ideal resistor with a constant impedance value in the corresponding frequency band, while keeping all other parameters of the model unchanged, and the simulation is run again; by comparing the frequency shift and amplitude change of the resonant point before and after the replacement, the contribution of the parasitic parameters of the port's impedance to ground to the resonance is evaluated, thereby determining whether the corresponding resonant point is dominated by the local resonance of the port.

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