EMC simulation modeling and optimization prediction method based on permanent magnet brushless direct current motor driver

Abstract

The invention discloses an EMC simulation modeling and optimization prediction method based on a permanent magnet brushless direct current motor driver. The method comprises the steps of obtaining first interference source data based on a driver real object; performing near-field electric field simulation based on the primary driver PCB and the first interference source data to obtain a primary near-field electric field radiation simulation cloud picture; obtaining an optimized driver PCB based on the initial edition of the near-field electric field radiation simulation cloud picture, and performing near-field electric field simulation based on the optimized driver PCB and the first interference source data to obtain an optimized near-field electric field radiation simulation cloud picture; judging whether optimization design is needed or not according to the near-field electric field radiation simulation nephograms obtained twice; and if the optimization design is not needed, acquiring second interference source data corresponding to the optimized driver PCB and judging whether the second interference source data reaches a preset target, and if the second interference source data does not reach the preset target, continuing optimization based on the optimized near-field electric field radiation simulation cloud picture. The method is low in complexity, rapid and accurate in simulation and lower in cost.

Description

Technical Field

[0001] The present invention 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 DC motor driver. Background Art

[0002] Permanent magnet brushless DC motors have the advantages of small size, light weight, high torque density and efficiency, and a wide speed regulation range. They inherit the advantages of convenient speed regulation control, low control cost, good torque characteristics and fast response of DC motors. At the same time, they also have the advantages of AC motors, such as simple structure, reliable operation and easy maintenance. Since the 1970s, they have been widely used and have now become one of the commonly used motors that are popular in applications. Power electronic devices are widely used in the drive and control of permanent magnet brushless DC motors. The research on the electromagnetic interference of power electronic devices has become an issue that must be considered in the design process of motor systems.

[0003] In permanent magnet brushless DC motor drivers, the widely used semiconductor switching devices and PWM modulation technology greatly improve the dynamic performance of the motor while also having an inescapable impact on the electromagnetic compatibility performance of the motor system. The voltage and current jumps of the switching devices and the signal distortion caused by the high-order harmonics of the PWM signals constitute the main electromagnetic noise sources of the motor driver. The motor driver is processed from a driver PCB. Optimizing the EMC of the PCB is beneficial to improving the electromagnetic compatibility performance of the motor system.

[0004] Currently, the EMC optimization of traditional PCBs is carried out by scanning the PCB in an electromagnetic compatibility anechoic chamber and performing near-field electric field scanning with a spectrum analyzer, and then analyzing and rectifying according to engineering experience. This rectification scheme relying on experience has uncertainty, a long time period and high costs. Therefore, electromagnetic simulation software is used to assist in rectification in engineering. Existing PCB electromagnetic simulations have high accuracy, but they require expert experience in signal extraction and highly complex modeling methods. Often, for specific objects in actual engineering, due to problems such as difficult parameter settings and model design defects, the simulation of the engineering object fails. Summary of the Invention

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

[0006] To achieve the above object, the present invention provides an EMC simulation modeling and optimization prediction method based on a permanent magnet brushless DC motor driver, including:

[0007] Obtain the initial version of the driver PCB and process it to obtain the driver physical object; obtain the first interference source data based on the driver physical object;

[0008] Perform near-field electric field simulation based on the initial version of the driver PCB and the first interference source data to obtain the initial version of the near-field electric field radiation simulation cloud map; obtain the optimized driver PCB based on the initial version of the near-field electric field radiation simulation cloud map, and perform near-field electric field simulation based on the optimized driver PCB and the first interference source data to obtain the optimized near-field electric field radiation simulation cloud map;

[0009] Judge whether optimization design is required based on the initial version of the near-field electric field radiation simulation cloud map and the optimized near-field electric field radiation simulation cloud map; if optimization design is not required, obtain the second interference source data corresponding to the optimized driver PCB and judge whether the preset target is reached. If not, continue to optimize based on the optimized near-field electric field radiation simulation cloud map.

[0010] Optionally, 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:

[0011] After connecting the driver physical object, the power supply and the permanent magnet brushless DC motor, perform electromagnetic compatibility anechoic chamber scanning on the motor system to obtain motor system radiation data; perform near-field scanning on the driver physical object to obtain driver near-field electric field radiation data.

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

[0013] Compare the motor system radiation data with the standard data to judge whether the motor system radiation noise exceeds the standard. If it exceeds the standard, store the motor system radiation data and the exceeding frequency; based on the scanning frequency range, perform near-field electric field scanning on the driver physical object through a spectrum analyzer and a near-field probe to obtain driver near-field electric field radiation data, and mark the scanning position points, where the scanning frequency range includes the exceeding frequency.

[0014] Optionally, the process of performing near-field electric field simulation based on the initial version of the driver PCB and the first interference source data to obtain the initial version of the near-field electric field radiation simulation cloud map includes:

[0015] Obtain interference devices based on the first interference source data and construct corresponding interference source models; construct an electromagnetic finite element simulation model based on the initial version of the driver PCB; perform near-field electric field simulation 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.

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

[0017] Extract the frequency bands in the near-field electric field radiation data of the driver where the radiation value exceeds the preset range, and determine the 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 frequencies exceeding the standard in the radiation data of the motor system, and determine the interfering devices with the dark room scan frequencies exceeding the standard.

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

[0019] Based on the electric field radiation distribution of the initial near-field electric field radiation simulation cloud map and the laws of electromagnetic interference generation and propagation, obtain an optimized driver PCB. Based on the optimized driver PCB and the interfering devices, construct corresponding electromagnetic finite element simulation models and interference source models respectively for near-field electric field simulation, and obtain the optimized near-field electric field radiation simulation cloud map.

[0020] Optionally, determine whether the near-field electric field radiation of the optimized near-field electric field radiation simulation cloud map and the radiation drop value at the frequencies exceeding the standard meet the requirements. If not, optimization design is required.

[0021] The present invention also provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor. The processor executes the computer program to implement the steps of the above method.

[0022] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0023] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the above method are implemented.

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

[0025] The present invention combines traditional testing and simulation technologies, proposes a simulation strategy that does not rely on the expert experience of signal extraction and high-complexity modeling means, uses the 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, significantly reduces the number of times of using the dark room site, saves a large amount of dark room scan experiment costs for the driver PCB designers, and reduces the later rectification costs of the driver PCB caused by EMC problems. Description of the Drawings

[0026] The drawings constituting a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0027] Figure 1 Flowchart of the EMC simulation modeling and optimization prediction method for the permanent magnet brushless DC motor driver according to the embodiment of the present invention. Specific embodiments

[0028] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

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

[0030] Embodiment 1

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

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

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

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

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

[0036] Compare the radiation data of the motor system with the standard data to determine whether the radiation noise of the motor system exceeds the standard. If it exceeds the standard, store the radiation data of the motor system and the exceeding frequency; based on the scanning frequency range, perform a near-field electric field scan on the physical driver through 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, where the scanning frequency range includes the exceeding frequency.

[0037] Specifically, in the working interface of the software Altium Designer, design the initial version of the PCB for the permanent magnet brushless DC motor driver, process the PCB into a board, solder components on the PCB board to make the physical driver; connect the physical driver to the power supply and the permanent magnet brushless DC motor, conduct electromagnetic compatibility anechoic chamber scanning on the motor system to obtain the radiation data of the motor system, and conduct near-field scanning on the physical driver to obtain the near-field electric field radiation data of the driver.

[0038] Exemplarily, in the software Altium Designer, design the initial version of the driver PCB. The PCB design process needs to comply with the PCB layout and wiring rules for EMC design, process the PCB into a board, and solder components on the PCB board to make the physical driver.

[0039] After the physical driver is made, connect it to the power supply and the permanent magnet brushless DC motor to form a permanent magnet brushless DC motor system. In the electromagnetic compatibility anechoic chamber, scan and test the radiation characteristics of the motor system, compare the test results with the GJB151B - 2013 RE102 standard, judge whether the radiation noise of the motor system exceeds the standard, and record the anechoic chamber scanning radiation data.

[0040] After determining that the anechoic chamber scanning radiation of the permanent magnet brushless DC motor system exceeds the standard, record the overall radiation data and the exceeding frequency. Through the spectrum analyzer and near-field probe, conduct a comprehensive near-field electric field scan on the physical driver of the motor system, mark the scanning positions, and focus on scanning devices that may cause radiation exceeding the standard, such as switching tubes and drive chips. The scanning frequency range covers the exceeding frequency. Export the near-field electric field scan results from the spectrum analyzer through a USB flash drive, analyze and process the scan data, make a curve graph of the near-field electric field radiation data of the physical driver and an interference source data file. There are the following two precautions in the analysis process:

[0041] (1) Analyze the frequency bands with high radiation values in the curve graph of the near-field electric field radiation data to judge the interference devices that generate radiation on the physical driver PCB.

[0042] (2) Analyze the data points with high near-field electric field radiation values at the anechoic chamber scanning exceeding frequency to judge the devices on the physical driver of the motor system that affect the exceeding of the anechoic chamber scanning frequency.

[0043] Based on the initial version of the driver PCB and the first interference source data, conduct near-field electric field simulation to obtain the initial version of the near-field electric field radiation simulation cloud map; based on the initial version of the near-field electric field radiation simulation cloud map, obtain the optimized driver PCB, and based on the optimized driver PCB and the first interference source data, conduct near-field electric field simulation to obtain the optimized near-field electric field radiation simulation cloud map.

[0044] Furthermore, the process of conducting near-field electric field simulation based on the initial version of the driver PCB and the first interference source data to obtain the initial version of the near-field electric field radiation simulation cloud map includes:

[0045] Obtain interference devices based on the first interference source data and construct corresponding interference source models; construct an electromagnetic finite element simulation model based on the initial version of the driver PCB; perform near-field electric field simulation 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.

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

[0047] Extract the frequency bands in the near-field electric field radiation data of the driver where the radiation value exceeds the preset range, and judge the interference 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 frequencies where the radiation data of the motor system exceeds the standard, and judge the interference devices that exceed the standard in the darkroom scanning frequency.

[0048] Specifically, in the working interface of the software Ansys SIwave, import the initial version of the driver PCB and the interference source data, construct the electromagnetic finite element simulation model and the interference source model, perform the first near-field electric field simulation, obtain the near-field electric field radiation simulation cloud map of the PCB in the model test frequency band, analyze the results and propose an EMC optimization plan;

[0049] Exemplarily, convert the driver PCB designed by the software Altium Designer into an ODB++ format file, which can be recognized by the software Ansys SIwave, generate an electromagnetic finite element simulation model, and set the PCB material, layer stack, capacitance value, resistance value, etc. for the electromagnetic finite element simulation model.

[0050] Through the Add Voltage Source tool in the Home column of the software Ansys SIwave, create an interference source model. The selection object of the interference source model is preferably the device corresponding to the radiation generated by the physical driver of the driver. After the interference source model is created, the software Ansys SIwave automatically pops up the electromagnetic interference radiation assignment interface, select the Frequency Dependent item and import the interference source data file to assign the actual near-field electric field radiation energy to the interference source model.

[0051] After determining that the electromagnetic finite element simulation model and the interference source model of the driver PCB are designed correctly, use the Compute NearField tool in the Simulation column of the software Ansys SIwave. In the popped-up interface, select the Use source defined in project item and set the scanning frequency range and the number of mesh divisions, and select the Launch item to perform near-field electromagnetic simulation. After the simulation is completed, view the simulation results in the Results column. There are the following three precautions in the process of analyzing the simulation results:

[0052] (1) Select item |E| in the Field Quantity to Plot column;

[0053] (2) Select the Logarithmic item in the Plot Scale column;

[0054] (3) Select the Max.E Field item in the Max.FieldPlot column.

[0055] On the working interface of the software Ansys SIwave, observe and analyze the near-field electric field simulation nephogram of the electromagnetic finite element simulation model of the driver PCB. Observe and analyze whether the near-field electric field radiation distribution of the nephogram at each frequency is consistent with the near-field electric field scanning radiation distribution of the physical driver. If the deviation is large, adjust the selection of the interference source until the results are consistent, and record the finally selected interference source device.

[0056] Furthermore, the process of obtaining the optimized near-field electric field radiation simulation nephogram includes:

[0057] Based on the electric field radiation distribution of the initial near-field electric field radiation simulation nephogram and the laws of electromagnetic interference generation and propagation, obtain an optimized driver PCB. Based on the optimized driver PCB and the interference device, respectively construct corresponding electromagnetic finite element simulation models and interference source models for near-field electric field simulation, and obtain the optimized near-field electric field radiation simulation nephogram.

[0058] Specifically, according to the electric field radiation distribution of the near-field electric field radiation simulation nephogram, conduct EMC optimization design for the severely radiated areas of the electric field, and propose targeted optimization solutions for the PCB layout and wiring.

[0059] According to the PCB optimization plan, use the software Altium Designer to design an optimized version of the driver PCB. Follow the previous operations to convert the ODB++ format file, generate the electromagnetic finite element simulation model, set the electromagnetic finite element simulation model, create the interference source model, and perform the near-field electric field radiation simulation operation in sequence. The operations are the same as before. The only thing to note is that due to the different layout and wiring of the optimized PCB and the initial PCB, the position of the interference source model in the optimized PCB model will be different from that in the initial PCB model, but the selected interference source objects must be the same.

[0060] Based on the initial near-field electric field radiation simulation nephogram and the optimized near-field electric field radiation simulation nephogram, judge whether optimization design is required; if optimization design is not required, obtain the second interference source data corresponding to the optimized driver PCB and judge whether the preset target is reached. If not, continue to optimize based on the optimized near-field electric field radiation simulation nephogram.

[0061] Furthermore, it is determined whether the near-field electric field radiation of the optimized near-field electric field radiation simulation cloud diagram and the radiation reduction value at the excessive frequency meet the requirements. If not, the design needs to be optimized.

[0062] Specifically, compare and analyze the near-field electric field radiation simulation cloud maps of the optimized driver PCB and the initial driver PCB, and observe 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. If the radiation is significantly reduced, the optimized driver PCB will be processed into a board, and the components will be soldered to the PCB board to make a physical driver. Otherwise, the design will be optimized again until the radiation of the near-field electric field simulation is significantly reduced.

[0063] The optimized version of the driver PCB is made into a physical product, connected to the power supply and permanent magnet brushless DC motor, and near-field electric field scanning and electromagnetic compatibility darkroom scanning experiments are carried out. If the darkroom scanning results show that the radiation is significantly reduced and reaches the expected goal, the EMC optimization design of the driver PCB is passed. Otherwise, the reasons for the design failure are analyzed, and PCB modeling, simulation prediction, and physical production of the driver are carried out again.

[0064] This embodiment further provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above method.

[0065] This embodiment also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0066] This embodiment also provides a computer program product, including a computer program, which implements the steps of the above method when executed by a processor.

[0067] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An EMC simulation modeling and optimization prediction method based on a permanent magnet brushless DC motor driver, characterized in that: The following steps are involved: Obtain the first version of the driver PCB and process it to obtain the actual driver; Obtaining first interference source data based on the driver object; Performing near-field electric field simulation based on the initial version of the driver PCB and the first interference source data to obtain an initial version of near-field electric field radiation simulation cloud map; Based on the first version of the near-field electric field radiation simulation cloud map, an optimized driver PCB is obtained; based on the optimized driver PCB and the first interference source data, a near-field electric field simulation is performed to obtain an optimized near-field electric field radiation simulation cloud map; Determine whether the design needs to be optimized based on the initial version of the near-field electric field radiation simulation cloud map and the optimized near-field electric field radiation simulation cloud map; If the design does not need to be optimized, the second interference source data corresponding to the optimized driver PCB is obtained and it is determined whether the preset target is achieved. If not, the optimization is continued based on the optimized near-field electric field radiation simulation cloud map.

2. The EMC simulation modeling and optimization prediction method based on the permanent magnet brushless DC motor driver according to claim 1 is characterized in that: 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 the physical driver, power supply and permanent magnet brushless DC motor are connected, the motor system is scanned in an electromagnetic compatibility darkroom to obtain the radiation data of the motor system; Perform near-field scanning on the actual driver to obtain the driver's near-field electric field radiation data.

3. The EMC simulation modeling and optimization prediction method based on the permanent magnet brushless DC motor driver according to claim 2 is characterized in that: The process of performing near-field scanning on the actual drive and obtaining the near-field electric field radiation data of the drive includes: The motor system radiation data is compared with the standard data to determine whether the motor system radiation noise exceeds the standard. If it exceeds the standard, the motor system radiation data and the exceeding frequency are stored; based on the scanning frequency range, the near-field electric field of the actual driver is scanned by a spectrum analyzer and a near-field probe to obtain the driver's near-field electric field radiation data, and the scanning position points are marked, wherein the exceeding frequency is included based on the scanning frequency range.

4. The EMC simulation modeling and optimization prediction method based on the permanent magnet brushless DC motor driver according to claim 1 is characterized in that: A process of performing near-field electric field simulation based on the preliminary version of the driver PCB and the first interference source data to obtain a preliminary version of the near-field electric field radiation simulation cloud map includes: Based on the first interference source data, an interference device is obtained and a corresponding interference source model is constructed; based on the initial version of the driver PCB, an electromagnetic finite element simulation model is constructed; based on the interference source model and the electromagnetic finite element simulation model, a near-field electric field simulation is performed to obtain an initial version of the near-field electric field radiation simulation cloud map.

5. The EMC simulation modeling and optimization prediction method based on permanent magnet brushless DC motor driver according to claim 4 is characterized in that: The process of obtaining the jammer device includes: Extract the frequency bands where the radiation values ​​exceed the preset range from the near-field electric field radiation data of the driver, and judge the interference devices based on the frequency bands where the radiation values ​​exceed the preset range; analyze the data points with high near-field electric field radiation values ​​at the exceeding frequencies of the motor system radiation data, and judge the interference devices whose darkroom scanning frequencies exceed the standard.

6. The EMC simulation modeling and optimization prediction method based on permanent magnet brushless DC motor driver according to claim 5 is characterized in that: 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 version of the 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 respectively constructed to perform near-field electric field simulation, and an optimized near-field electric field radiation simulation cloud map is obtained.

7. The EMC simulation modeling and optimization prediction method based on the permanent magnet brushless DC motor driver according to claim 3 is characterized in that: Determine whether the near-field electric field radiation of the optimized near-field electric field radiation simulation cloud diagram and the radiation reduction value at the excessive frequency meet the requirements. If not, the design needs to be optimized.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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