An EMC simulation modeling and optimization prediction method based on permanent magnet brushless DC motor driver

Abstract

The application discloses an EMC simulation modeling and optimization prediction method based on a permanent magnet brushless DC motor driver, which comprises the following steps: obtaining first interference source data based on a driver physical object; performing near-field electric field simulation on the first interference source data based on a preliminary version of a driver PCB to obtain a preliminary near-field electric field radiation simulation cloud picture; obtaining an optimized driver PCB based on the preliminary near-field electric field radiation simulation cloud picture, performing near-field electric field simulation on the first interference source data based on the optimized driver PCB to obtain an optimized near-field electric field radiation simulation cloud picture; determining whether optimization design is needed according to the two obtained near-field electric field radiation simulation cloud pictures; if the optimization design is not needed, obtaining second interference source data corresponding to the optimized driver PCB and determining whether a preset target is reached, and if the preset target is not reached, continuing optimization based on the optimized near-field electric field radiation simulation cloud picture. The method has low complexity, fast and accurate simulation and lower cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electromagnetic compatibility simulation, and particularly relates to an EMC simulation modeling and optimization prediction method based on a permanent magnet brushless direct current motor driver. BACKGROUND

[0002] The permanent magnet brushless direct current motor has the advantages of small size, light weight, high torque density and efficiency, wide speed regulation range, etc., and inherits the advantages of direct current motor, such as convenient speed control, low control cost, good torque characteristics and fast response. At the same time, it also has the advantages of alternating current motor, such as simple structure, reliable operation and easy maintenance. It has been widely used since the 1970s, and has become one of the commonly used motors. Power electronic devices are widely used in the driving and control of permanent magnet brushless direct current motors. The study of electromagnetic interference of power electronic devices has become a problem that must be considered in the design process of motor systems.

[0003] In the permanent magnet brushless direct current motor driver, the widely used semiconductor switching devices and PWM modulation technology greatly improve the dynamic performance of the motor, but also have an unavoidable impact on the electromagnetic compatibility performance of the motor system. The voltage and current jump of the switching device and the signal distortion caused by the high-order harmonics of the PWM signal constitute the main electromagnetic noise source of the motor driver. The motor driver is processed by the driver PCB. The optimization of the PCB EMC is beneficial to improve the electromagnetic compatibility performance of the motor system.

[0004] At present, the EMC optimization of the traditional PCB is through electromagnetic compatibility darkroom scanning, spectrum near-field electric field scanning of the PCB board, and then analyzing and rectifying according to engineering experience. This scheme relying on experience rectification has uncertainty, long time cycle and high cost. Therefore, electromagnetic simulation software is used to assist rectification in engineering. The existing PCB electromagnetic simulation has high accuracy, but it needs expert experience and high complexity modeling means for signal extraction. For specific objects in actual engineering, due to parameter setting difficulties, model design defects and other problems, the simulation of the engineering object fails. SUMMARY

[0005] To solve the above technical problems, the application provides an EMC simulation modeling and optimization prediction method based on a permanent magnet brushless direct current motor driver to solve the problems existing in the prior art.

[0006] To achieve the above purpose, the application provides an EMC simulation modeling and optimization prediction method based on a permanent magnet brushless direct current motor driver, which comprises:

[0007] Obtain the first interference source data based on the driver real object.

[0008] performing near-field electromagnetic field simulation on the first interference source data based on the preliminary driver PCB to obtain a preliminary near-field electromagnetic field radiation simulation cloud picture; performing near-field electromagnetic field simulation on the first interference source data based on the optimized driver PCB to obtain an optimized near-field electromagnetic field radiation simulation cloud picture;

[0009] determining whether optimization design is needed based on the preliminary near-field electromagnetic field radiation simulation cloud picture and the optimized near-field electromagnetic field radiation simulation cloud picture; if the optimization design is not needed, obtaining second interference source data corresponding to the optimized driver PCB and determining whether a preset target is reached, if the preset target is not reached, continuing optimization based on the optimized near-field electromagnetic field radiation simulation cloud picture.

[0010] Optionally, the first interference source data includes motor system radiation data and driver near-field electromagnetic field radiation data; the process of obtaining the first interference source data includes:

[0011] connecting the driver physical object, the power supply and the permanent magnet brushless direct current motor, performing electromagnetic compatibility darkroom scanning on the motor system to obtain motor system radiation data, and performing near-field scanning on the driver physical object to obtain driver near-field electromagnetic field radiation data.

[0012] Optionally, the process of performing near-field scanning on the driver physical object to obtain the driver near-field electromagnetic field radiation data includes:

[0013] comparing the motor system radiation data with standard data to determine whether the motor system radiation noise is over-standard, if the motor system radiation noise is over-standard, storing the motor system radiation data and over-standard frequency; performing near-field electromagnetic field scanning on the driver physical object based on the scanning frequency range through a spectrum analyzer and a near-field probe to obtain driver near-field electromagnetic field radiation data and mark the scanning position point, wherein the scanning frequency range includes the over-standard frequency.

[0014] Optionally, the process of performing near-field electromagnetic field simulation on the first interference source data based on the preliminary driver PCB to obtain a preliminary near-field electromagnetic field radiation simulation cloud picture includes:

[0015] obtaining interference devices based on the first interference source data and constructing corresponding interference source models; constructing an electromagnetic finite element simulation model based on the preliminary driver PCB; performing near-field electromagnetic field simulation on the interference source models and the electromagnetic finite element simulation model to obtain a preliminary near-field electromagnetic field radiation simulation cloud picture.

[0016] Optionally, the process of obtaining interference devices includes:

[0017] Extract the frequency band of the radiation value exceeding the preset range in the near-field electric field radiation data of the driver, and judge the interference device based on the frequency band of the radiation value exceeding the preset range; analyze the data points of the near-field electric field radiation value at the frequency exceeding the standard of the motor system radiation data, and judge the interference device whose darkroom scanning frequency exceeds the standard.

[0018] Optionally, the process of obtaining the optimized near-field electric field radiation simulation cloud picture comprises:

[0019] Based on the electric field radiation distribution of the preliminary version of the near-field electric field radiation simulation cloud picture and the generation and propagation rules of electromagnetic interference, an optimized driver PCB is obtained, near-field electric field simulation is performed based on the electromagnetic finite element simulation model and the interference source model corresponding to the optimized driver PCB and the interference device respectively, and an optimized near-field electric field radiation simulation cloud picture is obtained.

[0020] Optionally, whether the near-field electric field radiation of the optimized near-field electric field radiation simulation cloud picture and the radiation drop value at the frequency exceeding the standard meet the requirements is judged, and if not, optimization design is needed.

[0021] The application also provides a computer device, comprising a memory, a processor to store a computer program on the memory and run the computer program on the processor, and the processor executes the computer program to realize the steps of the above method.

[0022] The application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the steps of the above method.

[0023] The application also provides a computer program product, comprising a computer program, and the computer program is executed by a processor to realize the steps of the above method.

[0024] Compared with the prior art, the application has the following advantages and technical effects:

[0025] The application combines traditional testing and simulation technology, proposes a simulation strategy independent of signal extraction, expert experience and high complexity modeling means, uses EMC near-field electric field simulation results to guide the design optimization of the driver PCB, realizes fast and accurate simulation of the near-field electric field of the PCB, greatly reduces the number of traditional driver PCB experiments, greatly reduces the number of darkroom site uses, saves a large number of darkroom scanning experiment fees for the driver PCB designer, and reduces the late rectification cost of the driver PCB caused by EMC problems. BRIEF DESCRIPTION OF DRAWINGS

[0026] The drawings constituting a part of the application are used to provide further understanding of the application, the illustrative embodiments of the application and the description thereof are used to explain the application, and do not constitute improper limitation on the application. In the drawings:

[0027] Figure 1 This is a flowchart of the EMC simulation modeling and optimization prediction method for a permanent magnet brushless DC motor driver according to an embodiment of the present invention. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0030] Example 1

[0031] like Figure 1 As shown, this embodiment provides an EMC simulation modeling and optimization prediction method based on a permanent magnet brushless DC motor driver, including:

[0032] Obtain the initial driver PCB and fabricate it to obtain the physical driver; obtain the first interference source data based on the physical driver.

[0033] Furthermore, the first interference source data includes motor system radiation data and driver near-field electric field radiation data; the process of obtaining the first interference source data includes:

[0034] After connecting the physical driver, power supply, and permanent magnet brushless DC motor, the motor system was scanned in an electromagnetic compatibility anechoic chamber to obtain the radiation data of the motor system; a near-field scan of the physical driver was performed to obtain the near-field electric field radiation data of the driver.

[0035] Furthermore, the process of performing a near-field scan on the physical actuator to obtain near-field electric field radiation data of the actuator includes:

[0036] The radiation data of the motor system is compared with the standard data to determine whether the radiation noise of the motor system exceeds the standard. If it does, the radiation data of the motor system and the frequency of exceeding the standard are stored. Based on the scanning frequency range, the near-field electric field of the driver is scanned by a spectrum analyzer and a near-field probe to obtain the near-field electric field radiation data of the driver and mark the scanning position points. The frequency range includes the frequency of exceeding the standard.

[0037] Specifically, in the software Altium Designer work interface, a preliminary version of a permanent magnet brushless direct current motor driver PCB is designed, the PCB is processed into a board, and components are soldered on the PCB to make a driver physical object; the driver physical object is connected with a power supply and a permanent magnet brushless direct current motor, electromagnetic compatibility darkroom scanning is performed on the motor system, radiation data of the motor system are obtained, and near-field scanning is performed on the driver physical object to obtain near-field electric field radiation data of the driver.

[0038] For example, in the software Altium Designer, a preliminary version of a driver PCB is designed, the PCB design process needs to comply with the EMC design PCB layout and wiring rules, the PCB is processed into a board, and components are soldered on the PCB to make a driver physical object.

[0039] After the driver physical object is completed, it is connected with a power supply and a permanent magnet brushless direct current motor to form a permanent magnet brushless direct current motor system, the radiation characteristics of the motor system are scanned and tested in an electromagnetic compatibility darkroom, the test results are compared with the GJB151B-2013 RE102 standard, and it is determined whether the motor system radiation noise is excessive and the darkroom scanning radiation data are recorded;

[0040] After it is determined that the permanent magnet brushless direct current motor system darkroom scanning radiation is excessive, the overall radiation data and the excessive frequency are recorded, a spectrum analyzer and a near-field probe are used to perform comprehensive near-field electric field scanning on the driver physical object of the motor system, the scanning positions are marked, and devices such as switching tubes and driving chips that may cause radiation to be excessive are scanned. The scanning frequency range covers the excessive frequency, the near-field electric field scanning results are exported from the spectrum analyzer through a U disk, the scanning data are analyzed and processed, a near-field electric field radiation data curve graph of the driver physical object and an interference source data file are made, and the following two matters need attention during the analysis process:

[0041] (1) The frequency band with a high radiation value in the near-field electric field radiation data curve graph is analyzed, so as to determine the interference device of the driver PCB physical object that causes radiation;

[0042] (2) The data points with a high near-field electric field radiation value at the darkroom scanning excessive frequency are analyzed, so as to determine the device of the driver physical object that has an influence on the darkroom scanning frequency being excessive.

[0043] Based on the preliminary version of the driver PCB and the first interference source data, a preliminary near-field electric field radiation simulation cloud diagram is obtained; based on the preliminary near-field electric field radiation simulation cloud diagram, an optimized driver PCB is obtained, and based on the optimized driver PCB and the first interference source data, an optimized near-field electric field radiation simulation cloud diagram is obtained;

[0044] Further, the process of obtaining a preliminary near-field electric field radiation simulation cloud diagram based on the preliminary version of the driver PCB and the first interference source data includes:

[0045] obtain the interference device based on the first interference source data and construct a corresponding interference source model; construct an electromagnetic finite element simulation model based on the preliminary driver PCB; perform near-field electric field simulation based on the interference source model and the electromagnetic finite element simulation model to obtain a preliminary near-field electric field radiation simulation cloud diagram.

[0046] Further, the process of obtaining the interference device includes:

[0047] extract the frequency band with a radiation value exceeding a preset range in the driver near-field electric field radiation data, judge the interference device based on the frequency band with the radiation value exceeding the preset range, and analyze the data points with high near-field electric field radiation values at the frequency bands exceeding the standard in the motor system radiation data to judge the interference device with the darkroom scanning frequency exceeding the standard.

[0048] Specifically, in the software Ansys SIwave working interface, the preliminary driver PCB and the interference source data are imported, the electromagnetic finite element simulation model and the interference source model are constructed, the first near-field electric field simulation is performed, the model test frequency band PCB near-field electric field radiation simulation cloud diagram is obtained, the results are analyzed, and an EMC optimization scheme is proposed.

[0049] For example, the driver PCB designed by the software Altium Designer is converted into an ODB++ format file, which can be recognized by the software Ansys SIwave to generate an electromagnetic finite element simulation model, and the electromagnetic finite element simulation model is set for PCB material, layering, capacitance value, resistance value, etc.

[0050] The interference source model is created through the Add Voltage Source tool in the Home column of the software Ansys SIwave, the selection object of the interference source model is the device corresponding to the radiation generated by the driver in priority, the interference source model is created, the software Ansys SIwave automatically pops up the electromagnetic interference radiation assignment interface, the Frequency Dependent item is selected and the interference source data file is imported, and the actual near-field electric field radiation energy of the interference source model is assigned.

[0051] After determining that the driver PCB electromagnetic finite element simulation model and the interference source model are designed correctly, the Compute NearField tool in the Simulation column of the software Ansys SIwave is used, in the popped-up interface, the Use source defined in project item is selected and the scanning frequency range and mesh division number are set, the Launch item is selected to perform near-field electromagnetic simulation. After the simulation is completed, the simulation results are viewed in the Results column, and the following three matters need attention in the simulation result analysis process:

[0052] (1) Field Quantity to Plot column selects |E| item;

[0053] (2) Plot Scale column selects Logarithmic item;

[0054] (3) Max.Field Plot column selects Max.E Field item.

[0055] In the software Ansys SIwave working interface, the near-field electric field simulation cloud picture of the driver PCB electromagnetic finite element simulation model is observed and analyzed, whether the near-field electric field radiation distribution of the cloud picture at each frequency is consistent with the near-field electric field scanning radiation distribution of the driver physical object is observed and analyzed, if the deviation is large, the interference source selection is adjusted until the result is consistent, and the final interference source selection device is recorded.

[0056] Further, the process of obtaining the optimized near-field electric field radiation simulation cloud picture includes:

[0057] Based on the electric field radiation distribution of the preliminary version of the near-field electric field radiation simulation cloud picture and the electromagnetic interference generation and propagation law, the optimized driver PCB is obtained, the corresponding electromagnetic finite element simulation model and the interference source model are constructed based on the optimized driver PCB and the interference device, and the near-field electric field simulation is performed to obtain the optimized near-field electric field radiation simulation cloud picture.

[0058] Specifically, according to the electric field radiation distribution of the near-field electric field radiation simulation cloud picture, the EMC optimization design is performed for the serious electric field radiation area, and the targeted optimization scheme is proposed for the PCB layout and wiring.

[0059] According to the PCB optimization scheme, the optimized version of the driver PCB is designed by the software Altium Designer, and the ODB++ format file is converted, the electromagnetic finite element simulation model is generated, the electromagnetic finite element simulation model is set, the interference source model is created, and the near-field electric field radiation simulation is operated in sequence. The operation is consistent with the previous operation, and the only thing to note is that since the layout and wiring of the optimized version of the PCB are different from those of the preliminary version of the PCB, the position of the interference source model in the optimized version of the PCB model will be different from that in the preliminary version of the PCB model, but the interference source selection object must remain consistent.

[0060] Based on the preliminary version of the near-field electric field radiation simulation cloud picture and the optimized near-field electric field radiation simulation cloud picture, it is judged whether optimization design is needed; if optimization design is not needed, the second interference source data corresponding to the optimized driver PCB is obtained and it is judged whether the preset target is reached, if not, the optimization is continued based on the optimized near-field electric field radiation simulation cloud picture.

[0061] Further, it is judged whether the radiation reduction value of the near-field electric field radiation at the frequency exceeding the standard of the optimized near-field electric field radiation simulation cloud map meets the requirements, and if not, the design needs to be optimized.

[0062] Specifically, the near-field electric field radiation simulation cloud maps of the optimized driver PCB and the initial driver PCB are compared and analyzed, and it is observed whether the near-field electric field radiation of the optimized cloud map, especially the radiation at the frequency exceeding the standard in the darkroom scanning, is significantly reduced.

[0063] The optimized driver PCB is made into a physical product, connected to a power supply and a permanent magnet brushless DC motor, and then subjected to near-field electric field scanning and electromagnetic compatibility darkroom scanning experiments.

[0064] The embodiment also provides a computer device, which comprises a memory, a processor, a computer program stored on the memory and executable on the processor, and the processor executes the computer program to implement the steps of the above method.

[0065] The embodiment also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the above method.

[0066] The embodiment also provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the above method.

[0067] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for EMC simulation modeling and optimization prediction based on a permanent magnet brushless DC motor driver, characterized in that, Includes the following steps: Obtain the initial version of the driver PCB and process it to obtain the physical driver; The first interference source data is obtained based on the physical driver. The first interference source data includes motor system radiation data and driver near-field electric field radiation data; The process of obtaining the first interference source data includes: After connecting the physical driver, power supply, and permanent magnet brushless DC motor, the motor system was scanned in an electromagnetic compatibility anechoic chamber to obtain the radiation data of the motor system; the physical driver was scanned in the near field to obtain the near field electric field radiation data of the driver. Near-field electric field simulation is performed based on the initial driver PCB and the first interference source data to obtain an initial near-field electric field radiation simulation cloud map; an optimized driver PCB is obtained based on the initial near-field electric field radiation simulation cloud map; near-field electric field simulation is performed based on the optimized driver PCB and the first interference source data to obtain an optimized near-field electric field radiation simulation cloud map. The process of performing near-field electric field simulation based on the initial driver PCB and the first interference source data to obtain the initial near-field electric field radiation simulation cloud map includes: Based on the first interference source data, the interference device is obtained and the corresponding interference source model is constructed; an electromagnetic finite element simulation model is constructed based on the initial version of the driver PCB; near-field electric field simulation is performed based on the interference source model and the electromagnetic finite element simulation model to obtain the initial version of the near-field electric field radiation simulation cloud map. The process of obtaining the optimized near-field electric field radiation simulation cloud map includes: Based on the electric field radiation distribution and electromagnetic interference generation and propagation laws of the initial near-field electric field radiation simulation cloud map, an optimized driver PCB is obtained. Based on the optimized driver PCB and the interference device, corresponding electromagnetic finite element simulation models and interference source models are constructed to perform near-field electric field simulation and obtain an optimized near-field electric field radiation simulation cloud map. Based on the initial and optimized near-field electric field radiation simulation cloud maps, determine whether design optimization is needed. If no optimization is needed, obtain the second interference source data corresponding to the optimized driver PCB and determine whether the preset target has been achieved. If not, continue optimization based on the optimized near-field electric field radiation simulation cloud map. Determine whether the near-field electric field radiation and the radiation reduction value at the exceeding frequency in the optimized near-field electric field radiation simulation cloud map meet the requirements. If not, design optimization is needed.

2. The EMC simulation modeling and optimization prediction method based on a permanent magnet brushless DC motor driver according to claim 1, characterized in that, The process of performing a near-field scan on the physical actuator to obtain near-field electric field radiation data of the actuator includes: The radiation data of the motor system is compared with standard data to determine whether the radiated noise of the motor system exceeds the standard. If it does, the radiation data of the motor system and the frequency of exceeding the standard are stored. Based on the scanning frequency range, the near-field electric field of the driver is scanned by a spectrum analyzer and a near-field probe to obtain the near-field electric field radiation data of the driver and mark the scanning position points. The frequency range includes the frequency of exceeding the standard.

3. The EMC simulation modeling and optimization prediction method based on a permanent magnet brushless DC motor driver according to claim 1, characterized in that, The process of obtaining the interference device includes: Extract the frequency bands in the near-field electric field radiation data of the driver where the radiation value exceeds the preset range, and identify interfering devices based on the frequency bands where the radiation value exceeds the preset range; analyze the data points with high near-field electric field radiation values ​​at the frequency exceeding the standard in the radiation data of the motor system to identify interfering devices with excessive scanning frequency in the anechoic chamber.

4. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the steps of the method according to any one of claims 1-3.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method described in any one of claims 1-3.

6. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method described in any one of claims 1-3.

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