Modeling simulation method for radiation interference of hybrid stepping motor driving system

Abstract

The invention discloses a modeling simulation method for radiation interference of a hybrid stepping motor driving system, and aims to solve the problems that a radiation interference simulation model of a motor driving system is incomplete and a modeling method has high requirements on hardware configuration in the prior art. The system is divided into three modules of a driving control panel, a two-phase cable and a hybrid stepping motor for modeling, a PWM signal is extracted through monitoring equipment, a two-phase H-bridge driving circuit is established in Pspice software, and an output voltage time domain waveform is obtained through simulation; full-wave three-dimensional electromagnetic simulation models of the driving control panel, the two-phase cable and the hybrid stepping motor are respectively established in CST software, and corresponding voltage time domain waveform excitation is imported for simulation; carrying out vector superposition on the radiation interference electric field intensities of the three modules to obtain the overall radiation interference of the driving system; modeling precision and analysis efficiency are effectively improved, the method can be used for guiding improvement and optimization of radiation interference of a motor driving system in actual research and development, and the method has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of motor drive systems and their radiated interference analysis, and particularly to a method for modeling and simulating the radiated interference of a hybrid stepper motor drive system. Background Art

[0002] As a pulse motor widely used in industrial production and daily life, the hybrid stepper motor is based on the principle of electromagnetic induction and realizes precise operation by receiving electrical pulse signals, with advantages such as high precision and convenient control. With the continuous improvement of the performance of motor drive systems and power electronic devices, as well as the increasing system integration, power density, and operating frequency, the radiated interference problem of motor drive systems has become increasingly prominent and has become the focus of current research.

[0003] The development of motor drive systems tends to be efficient, high-performance, and ensure safety in use. However, power switching devices such as IGBTs (Insulated Gate Bipolar Transistors) generate large du / dt and di / dt during rapid turn-on and turn-off, and these rapid voltage and current changes can cause magnetic field radiation, thus triggering the radiated interference problem of motor drive systems. Especially under the wide application of pulse-width modulation technology (PWM), this problem is more significant.

[0004] To address this challenge, some relevant research work has been carried out in the industry. For example, some researchers have proposed an equivalent modeling method for PCB electromagnetic radiation. This method uses near-field scanning technology to capture the electromagnetic radiation of a PCB (Printed Circuit Board) in free space and simulates it through an ideal magnetic dipole model. However, this method may have certain errors at high frequencies and cannot fully and accurately reflect the actual electromagnetic radiation characteristics.

[0005] In addition, some researchers have used electromagnetic simulation software such as CST to evaluate the near-field and far-field emission levels of switching power supplies and put forward improvement suggestions. However, when establishing a radiated interference model for motor drive systems, these studies often only consider the motor housing model and the connected external cable model, while ignoring the influence of the motor stator winding on radiated interference. This results in an incomplete model that cannot comprehensively and accurately analyze the radiated interference situation of the system.

[0006] For example, 117313479A discloses an analysis method for the radiation interference of a motor drive system. This method constructs an equivalent circuit of the motor drive system through simulation, monitors the current data of the input cable, and extracts the interference source information from it. Then, a simplified model of the electric vehicle is constructed through simulation, and the interference source information is imported into the radiation cable model. Finally, the positions of the acquisition and monitoring points are determined according to the positions of the radiation cable models, the radiation information is collected, and the electric field strength and magnetic field strength of the acquisition and monitoring points are calculated according to the LOD-FDTD (Limits Of Deviation-Finite Difference Time Domain) method. Although this method breaks through the limitation of the time factor in calculating the electromagnetic field strength and improves the calculation efficiency, it mainly focuses on the radiation interference analysis in the field of electric vehicles and does not conduct detailed modeling and analysis on the internal structure of the motor drive system, such as the stator winding, etc.

[0007] In summary, there are many deficiencies in the existing radiation interference modeling and analysis methods for motor drive systems, such as overly simplified models, ignoring the influence of key components, and the need to improve calculation accuracy and efficiency. Therefore, there is an urgent need for a more comprehensive, accurate, and efficient radiation interference modeling and simulation method for motor drive systems to address the radiation interference challenges faced by current industrial stepper motor drive systems. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a radiation interference modeling and simulation method for a hybrid stepper motor drive system, which solves the problems of low calculation efficiency and difficulty in quickly and accurately obtaining the electric field strength and magnetic field strength in the field of radiation interference analysis of motor drive systems. Especially for high-power density and high-frequency motor drive systems, such as the motor drive system in electric vehicles, the analysis methods of the prior art are computationally complex, time-consuming, and have insufficient accuracy in analyzing the radiation interference of motor drive systems with complex structures.

[0009] To solve the above technical problems, the technical solution adopted by the present invention is: a radiation interference modeling and simulation method for a hybrid stepper motor drive system, including the following steps: Step1: Divide the hybrid stepper motor drive system into three modules: a drive control board, a two-phase cable, and a hybrid stepper motor; Step2: Establish electromagnetic simulation models for each module; Step3: Use the output voltage time-domain waveform of the drive circuit as the excitation, import it into the models of each module, and perform simulation to obtain the radiation interference of each module; Step4: Vectorially superimpose the radiation interference electric field strengths of each module to obtain the overall radiation interference of the system.

[0010] In a preferred embodiment, in Step1, the drive control board is further subdivided into a power circuit part and a control circuit part, and corresponding electromagnetic simulation models are established respectively.

[0011] In a preferred embodiment, Step1 further includes separately modeling and simulating the electromagnetic interference between the power circuit part and the control circuit part to evaluate its contribution to the overall radiation interference.

[0012] In a preferred embodiment, the specific steps of Step2 include: Step2.1: Establish a two-phase H-bridge drive circuit model in circuit simulation software, import the PWM signal for simulation, and obtain the time-domain waveform of the output voltage. Step2.2: Establish full-wave three-dimensional electromagnetic simulation models of the drive control board, two-phase cables, and hybrid stepper motor respectively in three-dimensional electromagnetic simulation software.

[0013] In a preferred embodiment, the circuit simulation software in Step2.1 is Pspice software.

[0014] In a preferred embodiment, the three-dimensional electromagnetic simulation software in Step2.2 is CST software.

[0015] In a preferred embodiment, when establishing the three-dimensional electromagnetic simulation model of the hybrid stepper motor in Step2.2, the influence of the motor's housing structure and material properties on radiation interference is also considered.

[0016] In a preferred embodiment, the specific steps of Step3 include: Step3.1: Use the time-domain voltage waveform obtained in Step2.1 as the excitation, import it into the drive control board model established in Step2.2, and perform simulation to obtain the radiation interference of the drive control board. Step3.2: Use the time-domain voltage waveform of the cable as the excitation, import it into the two-phase cable model established in Step2.2, and perform simulation to obtain the radiation interference of the two-phase cable. Step3.3: Use the time-domain voltage waveform of the motor as the excitation, import it into the hybrid stepper motor model established in Step2.2, and perform simulation to obtain the radiation interference of the motor.

[0017] In a preferred embodiment, the time-domain voltage waveform of the cable in Step3.2 is based on the time-domain output voltage waveform obtained in Step2 or is obtained according to actual measurement.

[0018] In a preferred embodiment, the time-domain voltage waveform of the motor in Step3.3 is based on the time-domain output voltage waveform obtained in Step2 or is obtained according to actual measurement, and the model of the motor simplifies its excitation winding based on the equivalent wire harness method.

[0019] In a preferred embodiment, the method further includes Step 7: Optimize the design of the drive control board, two-phase cables, and hybrid stepper motor according to the obtained radiated interference of the overall hybrid stepper motor drive system to reduce the radiated interference level of the system.

[0020] In a preferred embodiment, the method further includes Step 8: Conduct a radiated interference test in an anechoic chamber to verify the accuracy of the simulation model and correct the simulation model according to the test results.

[0021] In a preferred embodiment, the method further includes Step 9: Analyze and evaluate the electromagnetic compatibility of the hybrid stepper motor drive system using the simulation results to guide the design and optimization of the system.

[0022] In a preferred embodiment, the method is applicable to hybrid stepper motor drive systems of different models and specifications, and the simulation parameters and models can be flexibly adjusted according to actual requirements.

[0023] The modeling and simulation method for radiated interference of a hybrid stepper motor drive system provided by the present invention has the following beneficial effects: 1. The present invention divides the radiated interference modeling of the hybrid stepper motor drive system into drive control board modeling, two-phase cable modeling, and hybrid stepper motor modeling, which is beneficial to analyzing the radiated interference level and influencing factors of each component, and then putting forward improvement and optimization opinions to guide actual research and development; 2. The modular radiated interference modeling method of the present invention does not ignore the microscopic structure of the PCB during the modeling process, and at the same time considers the influence of various active and passive devices on the board on the radiated interference, solves the problem of analyzing and calculating the radiated interference of industrial drive control PCBs, and improves the modeling accuracy and analysis efficiency; 3. The radiated interference model of the hybrid stepper motor drive system established by the present invention compares the simulation results of the radiated interference of the drive system with the radiated interference test results based on the anechoic chamber to verify the accuracy and effectiveness of the radiated interference modeling; 4. The present invention uses the FITD (Finite Integration technique in the Time Domain) method for calculation, which greatly shortens the calculation time, improves the calculation efficiency, and solves the problem of low calculation efficiency in the prior art; 5. The present invention considers the complex structure and actual situation of the motor drive system. When modeling the motor, it not only considers the housing model and external cable model, but also considers the influence of the motor stator winding on the radiated interference, solves the deficiencies in existing research, and makes the analysis results more accurate and reliable; 6. The field-circuit co-simulation of the present invention combines circuit simulation and electromagnetic simulation, achieving accurate solution of the radiation interference of the drive system, and solving the problem that some modeling methods have high requirements for modeling quality and hardware configuration and are not suitable for pre-research analysis in industrial development; 7. Through modular modeling and field-circuit co-simulation, the present invention realizes accurate solution of the radiation interference of the hybrid stepping motor drive system, not only improving the accuracy of analysis, but also maintaining high analysis efficiency; 8. The method of the present invention is also applicable to the analysis of radiation interference of different types of motor drive systems, has broad application prospects, and is of great significance for promoting the development and application of motor drive system technology; 9. Through bold attempts and innovations in aspects such as modular modeling, high-precision consideration, verification of model accuracy, efficient calculation methods, consideration of complex structures, field-circuit co-simulation, and wide applicability, the present invention provides a comprehensive and effective solution for the analysis of radiation interference of the hybrid stepping motor drive system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the technical flow chart of the method of the present invention; Figure 2 is the B+ phase drive circuit in the H-bridge drive circuit of the present invention; Figure 3 is the PWM_T_B+ path PWM signal sent by the CPU of the drive control board of the present invention; Figure 4 is the output voltage time-domain waveform of the drive control board provided by the embodiment of the present invention; Figure 5 is the simulation model of the drive control board provided by the embodiment of the present invention in the 3D working area of CST Microwave Studio; Figure 6 is the circuit model of the drive control board of the present invention in the circuit working area; Figure 7 is the radiation interference electric field intensity of the drive control board of the present invention in the horizontal polarization direction; Figure 8 is the radiation interference electric field intensity of the drive control board of the present invention in the vertical polarization direction; Figure 9 is the simulation model of the two-phase cable provided by the embodiment of the present invention in the 3D working area of CST Cable Studio; Figure 10 is the circuit model of the two-phase cable of the present invention in the circuit working area; Figure 11 is the radiation interference electric field intensity of the two-phase cable of the present invention in the horizontal polarization direction; Figure 12is the radiated interference electric field strength of the two-phase cable of the present invention in the vertical polarization direction; Figure 13 is the simulation model of the hybrid stepper motor provided by the embodiment of the present invention in the 3D working area of CST Microwave Studio; Figure 14 is the circuit model of the hybrid stepper motor of the present invention in the circuit working area; Figure 15 is the radiated interference electric field strength of the hybrid stepper motor of the present invention in the horizontal polarization direction; Figure 16 is the radiated interference electric field strength of the hybrid stepper motor of the present invention in the vertical polarization direction; Figure 17 is the simulation result of the radiated interference of the hybrid stepper motor drive system of the present invention in the horizontal polarization direction; Figure 18 is the simulation result of the radiated interference of the hybrid stepper motor drive system of the present invention in the vertical polarization direction; Figure 19 is the layout diagram of the radiated interference test scenario provided by the embodiment of the present invention; Figure 20 is the test result of the radiated interference of the hybrid stepper motor drive system of the present invention in the horizontal polarization direction; Figure 21 is the test result of the radiated interference of the hybrid stepper motor drive system of the present invention in the vertical polarization direction. Detailed implementation manners

[0025] The technical solutions in the present invention will be further described below with reference to the accompanying drawings and embodiments: Embodiment 1 As Figure 1 shown, a method for modeling and simulating the radiated interference of a hybrid stepper motor drive system includes the following steps: Determine the composition of the radiated interference source and the simulation model. The radiated interference source is the du / dt and di / dt caused by the rapid on-off of the power switching device on the drive control board. These du / dt and di / dt contain rich high-order harmonics, which propagate in the drive control board, two-phase cable, and hybrid stepper motor, and at the same time form a closed loop to radiate energy outward. Therefore, according to the modeling idea of modular radiated interference, the drive system simulation model includes a drive control board model, a two-phase cable model, and a hybrid stepper motor model.

[0026] On the premise of ensuring the timing, the PWM signal sent by the CPU (Central Processing Unit) during the operation of the drive control board is extracted by the monitoring device, and a two-phase H-bridge drive circuit is established in the Pspice software. Finally, the PWM signal is imported into the built two-phase H-bridge drive circuit, and the time-domain waveform of the output voltage of the two-phase H-bridge drive circuit on the drive control board is obtained through simulation. This output voltage time-domain waveform excitation is input into the stepping motor through two-phase cables to excite the stator windings.

[0027] Import the PCB design file of the drive control board into the CST MWS studio, adjust the PCB material properties and component parameters, and establish a full-wave three-dimensional electromagnetic simulation model of the PCB. Apply a DC voltage excitation to the drive control board, and at the same time import the collected PWM signal to simulate the radiation interference of the drive control board.

[0028] According to the geometric dimensions and material properties of the cables, a full-wave three-dimensional electromagnetic simulation model of the two-phase cables is established in the CST Cable studio, and the voltage time-domain waveform excitation of the cables is imported to simulate the radiation interference of the two-phase cables.

[0029] Use the equivalent wire harness method to simplify the excitation windings of the hybrid stepping motor, establish a three-dimensional model of the motor after winding simplification, import the three-dimensional model into the CST MWS studio, import the voltage time-domain waveform excitation of the motor, and simulate the radiation interference of the motor.

[0030] Vectorially superimpose the radiation interferences of the drive control board, the two-phase cables and the hybrid stepping motor to obtain the overall radiation interference of the hybrid stepping motor drive system.

[0031] Operate the hybrid stepping motor under the rated working conditions, conduct a radiation interference test on the hybrid stepping motor drive system in the anechoic chamber, and compare the radiation interference test results with the simulation results to verify the accuracy of the simulation model.

[0032] This embodiment establishes a radiation interference simulation model of the hybrid stepping motor drive system according to Step in Figure 1 , analyzes and calculates the radiation interference electric field strengths generated by the drive control board, the two-phase cables and the stepping motor, and at the same time considers the influence of the spatial layout of the system components on the radiation interference, and can accurately obtain the radiation interference characteristics of the hybrid stepping motor drive system.

[0033] As Figure 2As shown, the B+ phase drive circuit is a half-bridge drive circuit based on Pspice software. The circuit simulation model at least includes: a half-bridge gate driver, a half-bridge circuit composed of two MOSFET switches, a rectifier diode, resistors, and capacitors. The B+ phase drive circuit receives the PWM signal sent from the CPU and drives two MOSFET switches to work through the half-bridge gate driver chip UCC27710DR. The B+ phase drive circuit, A- phase drive circuit, B+ phase drive circuit, and B- phase drive circuit together constitute a two-phase H-bridge drive circuit. The specific data is as follows: the +GATE voltage is 1.5V, the +BUS voltage is 48V, the capacitors C2, C4, and C5 are respectively 1 μF, 1 μF, and 0.1 μF, and the resistors R1, R4, R5, R7, R9, R11, R13, R16, R94, and R96 are respectively 20 Ω, 20 Ω, 22 Ω, 0.47 Ω, 100 kΩ, 22 Ω, 100 kΩ, 0.02 Ω, 22 Ω, and 22 Ω. The models of the diodes D4 and D6 are both B2100A, and the models of the diodes D14 and D15 are both EP05FA20. The frequencies of the PWM waves PWM_T_B+ and PWM_B_B+ are 15 kHz, the high level of the output voltage is 3.3V, and the low level is 0V. After connecting the circuit, set the simulation time to 1 ms, set a probe at the B+ phase output terminal, and run the simulation circuit to obtain the output voltage time-domain waveform as Figure 3 shown. At the same time, export the data of the voltage time-domain waveform in ASCII file format.

[0034] The full-wave 3D electromagnetic simulation model of the drive control board includes a 3D model and a circuit model. The 3D model is generated by importing the PCB design file into the CST MWS 3D workspace, and the circuit model is formed by connecting the S-parameter model or Spice model of the active devices on the drive control board to the corresponding ports.

[0035] When importing the PCB design file into the CST software for analysis and calculation, it is necessary to convert the PCB source file into an ODB++ format file. The ODB++ format file is a common PCB production file, which contains all the information for manufacturing and assembling printed circuit boards, such as copper layer images, board layer stacks, drilling, netlists, component layouts, etc. After importing the ODB++ file into the CST MWS 3D workspace, the PCB 3D models as shown in Figure 5 and Figure 6 can be obtained. The PCB size is 74 mm × 120 mm × 1.8 mm, and it is a 6-layer board structure, divided into 6 layers: "Top layer", "GND", "Midlayer1", "Midlayer2", "VCC", and "Bottom layer". The thickness of each layer is 0.03556 mm. The insulating dielectric layer material is FR4, the dielectric constant is 4.3, and the dielectric loss angle is 0.02.

[0036] After the ODB++ file is imported, in order to ensure that the component parameters on the PCB during simulation are consistent with the actual component parameters, on the one hand, it is necessary to import the S-parameter file or SPICE file that the software fails to recognize in the 3D workspace; on the other hand, it is necessary to adjust the S-parameter file or SPICE file of the components with incorrect recognition or inconsistent with the actual parameters. For multi-pin devices, such as active devices like MOSFETs, triodes, and half-bridge gate driver chips, their simulation models need to be imported into the circuit workspace. In the 3D model, first, discrete ports are established for the pins of MOSFETs, triodes, and half-bridge gate driver chips on the PCB. At the same time, corresponding terminals are automatically generated in the circuit workspace. Secondly, the Spice models of MOSFETs, triodes, and half-bridge gate driver chips are imported into the circuit workspace, and the pin ends of the Spice models are connected to the terminals automatically generated in the circuit workspace one by one according to the circuit design diagram, so as to realize the co-simulation and system analysis of the 3D model and the circuit.

[0037] There are two parts to the simulation excitation source of the PCB. The first part is the 48V DC input voltage of the entire drive system, and the second part is the 8-channel PWM signal output by the main control chip. Discrete ports are set at the 48V DC voltage input terminal and the 8-channel PWM signal input terminal of the 3D model. Corresponding terminals are automatically generated in the circuit workspace. The ASCII data file of the PWM signal is imported into the circuit workspace. At the same time, the 48V DC voltage excitation is set, and the PWM signal excitation and the 48V DC voltage excitation are connected to the corresponding terminals to complete the import of the excitation source.

[0038] According to the regulations of the radiation interference test frequency band, the solution frequency band is set to 30MHz~1GHz, the background material is set to Normal, the boundary condition is set to Open add space, the solver is set to the time-domain solver, the mesh division mode is Hexahedral, the solution method is selected as CST transient co-simulation, a spherical coordinate system is established with the geometric center of the PCB as the coordinate origin, and an electric field probe is defined at the position of (45, 270, 3000). Finally, the radiation interference simulation task of the drive control PCB is run to obtain the electric field strength at the (45, 270, 3000) probe. Figure 7 is the radiation interference electric field strength of the drive control board in the horizontal polarization direction. Figure 8 is the radiation interference electric field strength of the drive control board in the vertical polarization direction.

[0039] Such as Figure 9As shown, the two-phase cable is wound by a four-core stranded wire and has no braided shielding layer. The cable length is 1m, the diameter of the copper core is about 1.15mm, the outer diameter is about 8mm, and the insulating material used is PVC material. In the CST Cable studio, a simulation model of the two-phase cable is established according to the physical dimensions and material properties of the cable. The layout of the cable simulation model is adjusted according to the actual cable routing to make the simulation model consistent with the actual cable, as Figure 10 shown. At the same time, according to the size of the actual test platform, an ideal ground plane of 1.5m × 1.2m is constructed. The ideal ground plane is used to simulate good grounding conditions in EMC tests.

[0040] Consistent with the radiation interference solution settings of the drive control PCB, in the CST Cable studio, the solution frequency band is set to 30MHz - 1GHz, the background material is set to Normal, the boundary condition is set to Open add space, the solver is set to the time-domain solver, the solution method is selected as CST transient co-simulation, and an electric field probe is defined at the position (45, 270, 3000). The mesh division mode of the two-phase cable simulation model is Hexahedral TLM, and the mesh division strategy adopts an adaptive encryption strategy. Considering both the solution efficiency and solution accuracy, the FITD method is used in the present invention for calculation to shorten the calculation time and improve the calculation efficiency. In the 3D workspace of the CST Cable studio, discrete ports for cable excitation are set, corresponding terminals are automatically generated in the corresponding circuit workspace, the time-domain waveform excitation of the output voltage of the drive control board obtained by simulation is imported into the circuit workspace and connected to the corresponding terminals. Finally, the electric field intensity of the two-phase cable at the (45, 270, 3000) probe is obtained through field-circuit co-simulation Figure 11 is the radiation interference electric field intensity of the two-phase cable in the horizontal polarization direction, Figure 12 is the radiation interference electric field intensity of the two-phase cable in the vertical polarization direction.

[0041] As Figure 13 shown, the model of the hybrid stepper motor is the 57-type stepper motor. The modeling of the hybrid stepper motor includes stator modeling, rotor modeling, excitation winding modeling, and end cover modeling.

[0042] The hybrid stepper motor stator has 8 slots, and the slot type is a flat-bottom slot structure. The rotor is composed of permanent magnets and magnetic steels. The material of the stator is non-oriented electrical steel, the materials of the shaft and bearings are low-carbon steel, the material of the wire is pure copper, and the material of the end cover is aluminum alloy. Based on the above information, a three-dimensional model of the stepper motor stator, rotor, and end cover is established using Solidworks software. Minor structures are simplified without affecting the motor's radiation emission, which simplifies the modeling difficulty on the one hand and reduces the demand for computing resources and simulation time on the other hand.

[0043] The exciting winding of the motor is made by winding enameled wire in double strands. The winding is a bipolar winding. The exciting winding of each slot of the stator is wound 18 turns by two enameled wires. The diameter of the copper conductor of the enameled wire is 0.47 mm, and the thickness of the insulating outer coating is about 0.025 mm. In the simulation modeling of the radiation interference of the hybrid stepper motor, if the grid is set too large, the characteristics of the exciting winding cannot be accurately described; if the grid is set too small, the solution time will become longer and the hardware configuration requirements will also be higher. Therefore, the equivalent wire bundle method is used to simplify the exciting winding of the hybrid stepper motor. There are 18 turns in total for the coil of one exciting winding. Since it is wound in double strands, that is, there are 72 wires in one stator groove. When simplifying the core wire group composed of every 18 wires into a single wire, the equivalent radius of the wire is 0.81 mm, and thus 72 wires are simplified into 4 wires. Finally, the stator, rotor, exciting winding and end cover are assembled in Solidworks software to establish a complete 3D model of the hybrid stepper motor.

[0044] The 3D model of the hybrid stepper motor established in Solidworks software is imported into CST Microwave Studio to establish a full-wave three-dimensional electromagnetic simulation model of the motor. The solution settings for the radiation interference of the hybrid stepper motor are the same as those for the radiation interference of the driving control PCB. In CST Microwave Studio, the solution frequency band is set to 30 MHz - 1 GHz, the background material is set to Normal, the mesh division mode is Hexahedral, the boundary condition is set to Open add space, the solver is set to the time-domain solver, the solution method is selected as CST transient co-simulation, and an electric field probe is defined at the position (45, 270, 3000).

[0045] There are 8 windings in total on the stator poles. These 8 windings belong to two phases, A and B. Appropriate discrete ports are set on the cross-section of the 3D model of the exciting coil, and 8 terminals are automatically generated in the corresponding circuit working area. The output voltage excitation obtained from the simulation of the two-phase H-bridge drive circuit is connected to these 8 terminals, as Figure 14 shown. Finally, the electric field intensity of the hybrid stepper motor at the probe (45, 270, 3000) is obtained by solving through field-circuit co-simulation. Figure 15 This is the radiation interference electric field intensity of the hybrid stepper motor in the horizontal polarization direction. Figure 16 This is the radiation interference electric field intensity of the hybrid stepper motor in the vertical polarization direction.

[0046] After separately calculating the radiated interference electric field strengths of the drive control board, two-phase cable, and hybrid stepper motor, based on the principle of vector superposition of electromagnetic fields, the radiated interferences of these three components in the horizontal polarization direction and vertical polarization direction at the (45, 270, 3000) electric field probe are vectorially superimposed to obtain the radiated interferences of the hybrid stepper motor drive system in the horizontal polarization direction and vertical polarization direction, as Figure 17 and Figure 18 shown.

[0047] A radiated interference test is carried out in the anechoic chamber to verify the simulation model. Figure 19 is the test scenario built according to the EMC test standard, which includes an anechoic chamber, an antenna, an EMI receiver, and a series of supporting equipment. The test uses a broadband composite antenna to measure the electric field strengths in the vertical polarization and horizontal polarization directions in the frequency range of 30 MHz to 1 GHz. The equipment under test includes the drive control board, cable, and motor body in the HSM (Hybrid Stepper Motor) drive system. The equipment under test is placed on the test table, the height of the test table from the ground is 0.8 meters, and the broadband composite antenna is 3 meters away from the test table. The equipment under test is powered by a shielded cable under the turntable metal cover, and the other end of the cable is connected to an artificial power network. The height of the broadband composite antenna is adjustable to ensure that the maximum radiation intensity emitted by the equipment under test can be received at the corresponding height. At the same time, the antenna is connected to an EMI (Electromagnetic Interference) receiver outside the anechoic chamber, and the induced electromagnetic wave energy is transmitted to the receiver through a coaxial cable. Inside the receiver, the signal is amplified, filtered, and subjected to relevant operations and then converted into a digital form for spectrum analysis. Figure 20 and Figure 21 are respectively the radiated interferences in the horizontal polarization direction and vertical polarization direction of the hybrid stepper motor drive system measured in the anechoic chamber.

[0048] Comparing the simulation results with the test results, the overall trends are relatively consistent, and the amplitude levels at most frequency points also differ within the error range. There is a certain error in the amplitude in the vertical direction in the high-frequency band, and there is a difference of about 10 in the amplitude in the horizontal direction within the range of 100 MHz to 200 MHz. The above test results can show that the radiated interference simulation model of the hybrid stepper motor drive system established in this paper is accurate and effective. The spectral interference waveforms obtained through simulation are also consistent with the test results in the overall trend. There is an error of about 10 at some frequency points between the simulation results and the test waveforms, but it is also within the acceptable range. The overall process of modeling analysis and simulation solution is effective.

[0049] Embodiment 2 In another preferred embodiment, based on the above-mentioned Embodiment 1, this embodiment is basically the same as Embodiment 1, but is different in specific parameters and settings to demonstrate the diversity and practicality of the present invention.

[0050] In the establishment of the drive control board model, this embodiment uses different capacitance and resistance values, as well as different types of diodes. At the same time, the frequency of the PWM wave and the high and low levels of the output voltage are also adjusted. These changes are aimed at investigating the influence of different parameter settings on the simulation results of radiation interference.

[0051] In the establishment of the two-phase cable model, this embodiment changes parameters such as the length, copper core diameter, and outer diameter of the cable to simulate the influence of cables with different specifications and layouts on radiation interference.

[0052] In the establishment of the hybrid stepper motor model, this embodiment uses different types of stepper motors and adjusts parameters such as the number of stator slots, slot type structure, and material properties. In addition, the winding method and wire material of the excitation winding are also changed to investigate the influence of these changes on the radiation interference of the motor.

[0053] The above embodiment realizes the accurate modeling and simulation of the radiation interference of the hybrid stepper motor drive system through detailed steps and specific operation methods. This method not only considers the radiation interference of key components such as the drive control board, two-phase cable, and hybrid stepper motor, but also improves the accuracy and practicality of the simulation results through technical means such as field-circuit co-simulation and vector superposition. At the same time, the reliability of the simulation model is further ensured through experimental verification, providing strong support for the research and solution of the radiation interference problem of the motor drive system.

[0054] In the preferred solution, Step 1 further includes separately modeling and simulating the electromagnetic interference between the power circuit part and the control circuit part to evaluate its contribution to the overall radiation interference; the above settings further ensure the accuracy and reliability of the design. At the same time, the introduction of advanced filtering technologies and shielding measures effectively reduces the level of electromagnetic interference, laying a solid foundation for the stable operation of the system.

[0055] In the preferred solution, the circuit simulation software in Step 2.1 is Pspice software; with the above settings, by importing the circuit schematic diagram and performing simulation analysis, the circuit behavior can be accurately simulated and the performance can be evaluated; at the same time, using the advanced functions of Pspice, such as parameter scanning and temperature analysis, further optimizes the circuit design to ensure its stability and efficiency under different conditions.

[0056] In a preferred solution, the 3D electromagnetic simulation software in Step 2.2 is CST software; with the above settings, the performance of the stepper motor in a complex electromagnetic environment can be accurately simulated, including key parameters such as radiation pattern, gain, standing wave ratio, etc., providing strong data support for the design and optimization of the stepper motor, and ensuring that the final stepper motor product meets the performance index requirements.

[0057] In a preferred solution, when establishing the 3D electromagnetic simulation model of the hybrid stepper motor in Step 2.2, the influence of the motor's housing structure and material properties on radiation interference is also considered; with the above settings, the simulation model is closer to the actual operating conditions, effectively predicting the electromagnetic radiation characteristics of the motor under different working conditions, and providing a solid theoretical basis for subsequent electromagnetic compatibility design and optimization.

[0058] In a preferred solution, the voltage time-domain waveform of the cable in Step 3.2 is based on the output voltage time-domain waveform obtained in Step 2 or measured according to the actual situation; with the above settings, the accuracy and reliability of the voltage time-domain waveform are ensured, providing a solid foundation for subsequent motor system analysis and fault diagnosis. At the same time, this solution also considers the uncertainties in actual operation, improving the adaptability and robustness of the system.

[0059] In a preferred solution, the voltage time-domain waveform of the motor in Step 3.3 is based on the output voltage time-domain waveform obtained in Step 2 or measured according to the actual situation, where the motor model simplifies its exciting winding based on the equivalent wire harness method; with the above settings, the accuracy of the motor voltage waveform is ensured, while the computational complexity is simplified. Under the framework of the equivalent wire harness method, the dynamic response of the motor can be efficiently simulated, providing a solid foundation for subsequent control system design and optimization.

[0060] In a preferred solution, the method further includes Step 7: Optimize the designs of the drive control board, two-phase cable, and hybrid stepper motor according to the overall radiation interference of the hybrid stepper motor drive system obtained, so as to reduce the radiation interference level of the system; with the above settings, the electromagnetic compatibility of the system is further improved. In addition, it also includes Step 8: Conduct a comprehensive test on the optimized system to ensure that while reducing the radiation interference, it does not affect its drive performance and stability, thereby providing a more reliable stepper motor drive solution for users.

[0061] In a preferred solution, the method further includes Step 8: Conduct a radiation interference test in an anechoic chamber to verify the accuracy of the simulation model, and modify the simulation model according to the test results; with the above settings, it is ensured that the model is highly consistent with the actual situation, improving the reliability of subsequent design and testing. In addition, the solution also emphasizes the detailed recording and analysis of test data to continuously optimize the test process and improve the overall test efficiency and accuracy.

[0062] In a preferred embodiment, the method further includes Step 9: analyzing and evaluating the electromagnetic compatibility of the hybrid stepper motor drive system using the simulation results to guide the design and optimization of the system; the above settings can ensure the stable operation of the system in a complex electromagnetic environment, further improve the system efficiency, and ensure that the final product meets strict electromagnetic compatibility standards.

[0063] In a preferred embodiment, the method is applicable to hybrid stepper motor drive systems of different models and specifications, and the simulation parameters and models can be flexibly adjusted according to actual needs; the above settings ensure the wide applicability and high customizability of the method in different application scenarios, providing strong technical support and practical guidance for optimizing the performance of hybrid stepper motor drive systems.

[0064] In a preferred embodiment, the calculation method of the method is the FITD method, which combines the advantages of the finite element method (FEM) and the finite difference method (FDM). By solving the discrete equations on a three-dimensional unstructured grid, it can efficiently and accurately simulate fluid flow and heat transfer processes, is applicable to complex geometric shapes and flow conditions, has more accurate calculation results, shortens the calculation time, and improves the calculation efficiency.

[0065] In summary, the present invention proposes an innovative method for modeling and simulating the radiation interference of a hybrid stepper motor drive system. This method provides effective solutions to the core problems existing in the field of radiation interference analysis of motor drive systems, such as low computational efficiency and difficulty in quickly and accurately obtaining the electric field strength and magnetic field strength. Especially for high-power density and high-frequency motor drive systems, such as key components in electric vehicles, the present invention overcomes the limitations of the existing technology analysis methods in terms of complex calculation, long time consumption, and insufficient analysis accuracy for complex structures; by adopting a modular modeling concept, the present invention divides the radiation interference modeling of the hybrid stepper motor drive system into three major modules: drive control board modeling, two-phase cable modeling, and hybrid stepper motor modeling. This not only helps to independently and deeply analyze the radiation interference level and influencing factors of each component, but also enables the formulation of more targeted optimization strategies; compared with the previous modeling methods that only focused on single components or simple systems, the present invention constructs a more comprehensive and detailed analysis framework. With the help of professional software such as CST, full-wave three-dimensional electromagnetic simulation models of the drive control board, two-phase cables, and hybrid stepper motors are successfully established. These models can accurately reproduce the electromagnetic radiation characteristics in the actual physical environment, significantly improving the accuracy of the simulation results; in the modeling process, the present invention cleverly combines the circuit model and the three-dimensional electromagnetic model to achieve field-circuit co-simulation, thereby being able to more closely simulate the electromagnetic interference situation, comprehensively considering the fluctuations of current and voltage in the circuit and the distribution state of the electromagnetic field, laying a solid foundation for the accurate assessment of radiation interference; in addition, the present invention not only regards the power switching devices on the drive control board as radiation sources, but also incorporates the electromagnetic radiation inside the two-phase cables and the hybrid stepper motor. This measure makes the assessment of the system radiation interference level more comprehensive; in the modeling of the hybrid stepper motor, the present invention innovatively adopts the equivalent wire harness method to simplify the excitation winding, which greatly reduces the modeling difficulty, reduces the consumption of computing resources, and ensures a high simulation accuracy; finally, the present invention calculates the radiation interference electric field strength of each component separately and superimposes them according to the electromagnetic field vector superposition principle to obtain the overall radiation interference level of the system. This result can more accurately depict the distribution of the complex electromagnetic field in the actual situation, providing strong technical support for the analysis and optimization of the radiation interference of the motor drive system.

Claims

1. A modeling and simulation method for radiation interference of a hybrid stepping motor drive system, characterized in that: The following steps are involved: Step 1: Divide the hybrid stepper motor drive system into three modules: drive control board, two-phase cable and hybrid stepper motor; Step 2: Establish electromagnetic simulation model for each module; Step 3: Use the output voltage time domain waveform of the driving circuit as excitation and import it into the model of each module to simulate and obtain the radiation interference of each module; Step 4: Perform vector superposition of the radiation interference electric field strength of each module to obtain the overall radiation interference of the system.

2. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 1 is characterized in that: In the Step 1, the drive control board is further subdivided into a power circuit part and a control circuit part, and corresponding electromagnetic simulation models are established for each part.

3. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 2 is characterized in that: The Step 1 also includes separately modeling and simulating the electromagnetic interference between the power circuit part and the control circuit part to evaluate their contribution to the overall radiation interference.

4. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 1 is characterized in that: The specific steps of Step 2 include: Step 2.1: Establish a two-phase H-bridge drive circuit model in the circuit simulation software, and import the PWM signal for simulation to obtain the output voltage time domain waveform; Step 2.2: Establish full-wave three-dimensional electromagnetic simulation models of the drive control board, two-phase cable and hybrid stepper motor in the three-dimensional electromagnetic simulation software.

5. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 4 is characterized in that: The circuit simulation software in Step 2.1 is Pspice software.

6. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 4 is characterized in that: The three-dimensional electromagnetic simulation software in Step 2.2 is CST software.

7. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 4 is characterized in that: In Step 2.2, when establishing the three-dimensional electromagnetic simulation model of the hybrid stepper motor, the influence of the motor's housing structure and material properties on the radiation interference is also considered.

8. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 1 is characterized in that: The specific steps of Step 3 include: Step 3.1: Use the voltage time domain waveform obtained in Step 2.1 as excitation and import it into the drive control board model established in Step 2.2 to simulate and obtain the radiation interference of the drive control board; Step 3.2: Use the voltage time domain waveform of the cable as excitation and import it into the two-phase cable model established in Step 2.2 to simulate and obtain the radiation interference of the two-phase cable; Step 3.3: Use the motor’s voltage time domain waveform as excitation and import it into the hybrid stepper motor model established in Step 2.2 to simulate and obtain the motor’s radiation interference.

9. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 8 is characterized in that: The voltage time domain waveform of the cable in Step 3.2 is based on the output voltage time domain waveform obtained in Step 2 or obtained according to actual measurement.

10. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 8, characterized in that: The voltage time domain waveform of the motor in Step 3.3 is based on the output voltage time domain waveform obtained in Step 2 or obtained according to actual measurement, wherein the model of the motor is based on the equivalent wiring harness method to simplify its excitation winding.

11. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 1 is characterized in that: The method further includes Step 7: optimizing the design of the drive control board, the two-phase cable and the hybrid stepper motor according to the obtained overall radiation interference of the hybrid stepper motor drive system to reduce the radiation interference level of the system.

12. The modeling and simulation method for radiation interference of a hybrid stepping motor drive system according to claim 1, characterized in that: The method further comprises Step 8: performing a radiation interference test in a semi-anechoic chamber to verify the accuracy of the simulation model, and modifying the simulation model according to the test results.

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