Permanent magnet synchronous motor joint simulation method

Abstract

The invention discloses a permanent magnet synchronous motor joint simulation method, which comprises the following steps of: firstly, establishing a permanent magnet synchronous motor finite element model in Maxwell, and defining material nonlinear characteristics and motion boundary conditions; a motor drive control circuit is constructed in Simplorer, the finite element model is imported through a Twinbuild tool, and an electromagnetic-circuit joint simulation environment is established; creating a motor multi-body dynamic model and an external load model in Adams, and respectively exporting the motor multi-body dynamic model and the external load model into an FMU format and an Adamssub format; and finally, establishing an electromagnetic-circuit-mechanism joint simulation platform in the Simulink, and executing joint simulation. Compared with traditional joint simulation, according to the method, through electromagnetic-circuit-mechanism three-field real-time interaction, the motor can sense the load sudden change working condition, then the torque and current of the motor are rapidly adjusted through the PI controller, the problems that in engineering practice, the external load of the motor is not real, and the abnormal load is detected are solved, and the reliability of the motor is improved. And the crossing from an ideal load to an actual load is realized.

Description

Technical Field

[0001] This invention relates to the field of motor simulation technology, and in particular to a co-simulation method for permanent magnet synchronous motors. Background Technology

[0002] Today, generators provide power to both industrial production and daily life, and their applications are found in almost every industry, making them an indispensable piece of equipment in modern human society. Before an electric motor can be put into actual operation, it needs to be simulated and tested. However, traditional motor simulation methods have the following drawbacks:

[0003] I. Single software simulation cannot take into account the multi-physics coupling of electromagnetic fields, control circuits, mechanical dynamics and load characteristics.

[0004] Second, existing co-simulation solutions suffer from problems such as incompatible data interfaces, poor real-time performance, difficulty in closed-loop control, and unrealistic loads.

[0005] Third, the lack of a dynamic interaction mechanism between the load model and the motor model leads to a large deviation between the simulation results and the actual operating conditions. Summary of the Invention

[0006] The purpose of this invention is to provide a co-simulation method for permanent magnet synchronous motors. Compared with traditional single-physics simulation, this method realistically reflects the coupling effect between various physical fields under complex working conditions, avoiding errors and omissions caused by single simulation. Compared with traditional co-simulation, this method enables the motor to sense sudden load changes through real-time interaction of electromagnetic, circuit, and mechanism fields. Then, the motor torque and current are quickly adjusted through a PI controller, solving the problems of unrealistic external loads and abnormal load detection in engineering practice, and realizing the leap from "ideal load" to "actual load". In addition, this method also significantly shortens the simulation time through the FMU / Adams_sub standardized interface and motor model order reduction, thereby solving the problems mentioned in the background technology.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for co-simulation of permanent magnet synchronous motors includes:

[0009] Step 1: Create a finite element model of the permanent magnet synchronous motor in Maxwell, define the nonlinear characteristics of the material and the boundary conditions of motion, and set the winding excitation, number of turns, and current direction. In the Design Settings, check the "Enable transient-transient link with Twin Builder" option.

[0010] Step 2: Build the motor drive control circuit in Simplier. Import the finite element model and Simulink module using the Twinbuilder tool to establish an electromagnetic-circuit co-simulation environment and data transmission channel.

[0011] Step 3: Create the motor multibody dynamics model and the external load model in Adams, and export them as FMU format and Adams_sub format respectively.

[0012] Step 4: Deploy the S-Function module, FMU module, and Adams_sub module in Simulink, and connect them in sequence to form a joint simulation of electromagnetic-circuit-mechanism.

[0013] Step 5: Simulink is used as the main control program to perform co-simulation. The time step and total time are set to be the same in all software programs. The shorter the simulation step, the more accurate the results. The software programs achieve cross-platform data exchange through shared memory.

[0014] A further aspect of the present invention is that step 1 is specifically as follows:

[0015] Step 1.1: Establish the transient field model of the motor using the finite element method, draw the motor model, and set the materials of each component. The mathematical equations of the permanent magnet synchronous motor under the dq axis are as follows, where the d-axis refers to the axis aligned with the rotor magnetic pole direction (direct axis), and the q-axis refers to the axis orthogonal to the d-axis (quadrature axis):

[0016] Magnetic flux linkage equation:

[0017]

[0018] Voltage equation:

[0019]

[0020] Where ψ d ψ q L represents the flux linkage along the d and q axes; d and L q These are the d-axis and q-axis inductances of the motor, respectively; i d and i q These are the d-axis and q-axis currents, respectively; ψ f For permanent magnet flux linkage; R s ω is the stator phase resistance; e This refers to the electrical angular velocity of the motor.

[0021] Torque equation in dq coordinate system:

[0022]

[0023] Where T eFor electromagnetic torque; L d and L q These are the d-axis and q-axis inductances, respectively; U d U q and i d i q ψ represents the voltage and current along the d and q axes, respectively; f For permanent magnet flux linkage; P n This represents the number of pole pairs of the motor.

[0024] Equations of motion in the dq coordinate system:

[0025]

[0026] Where T e ω represents the electromagnetic torque; J represents the total moment of inertia of the rotor and load; B is the viscous friction coefficient of the system; y T is the mechanical angular velocity of the motor. L This represents the torque applied by the external load; P n This represents the number of pole pairs of the motor.

[0027] Step 1.2: Set various parameters for the materials in the material library, such as the BH curve and the demagnetization curve of the permanent magnet;

[0028] Step 1.3: Implement an adaptive mesh generation strategy to locally refine the mesh in the air gap region;

[0029] Step 1.4: Set the winding excitation, number of turns, current direction and boundary conditions. Change the default Votlage in the excitation options to External to allow the motor to accept current from the Simplier.

[0030] Step 1.5: Set parameters in the excitation to reduce the order of the motor. The reduced-order model can speed up the co-simulation process.

[0031] Step 1.6: In the Design Settings, check the "Enable transient-transient link with Twin Builder" option.

[0032] A further aspect of the present invention is that step 2 is specifically as follows:

[0033] Step 2.1: Build an SVPWM space vector pulse width modulation model in Simplier and set the dead time to 1μs to 10μs.

[0034] Step 2.2: Build an inverter circuit in Simplier. The inverter circuit consists of 6 transistors and 6 diodes. Connect the output of the SVPWM space vector pulse width modulation model to it.

[0035] Step 2.3: Build the Park and Clarke converter modules in Simplier. Connect the output terminals of the three-phase current to the input terminals of the Clarke converter module, and connect the output terminals of the Clarke converter module to the input terminals of the SVPWM module.

[0036] Step 2.4: Establish a dual closed-loop system consisting of a proportional-integral (PI) controller to control the motor speed and current respectively. The PI module is responsible for quickly adjusting the motor torque and current after the motor is subjected to an external load, enabling the motor to resist the external load.

[0037] The formula for calculating the current loop PI parameter is:

[0038]

[0039] Where k Ip Here, k is the proportional parameter of the current loop; Ii For the current loop integral; parameter L q R is the q-axis inductance of the motor. s Motor fixed resistor, T s This represents the system sampling time.

[0040] The formula for calculating the PI parameter of the speed ring is:

[0041]

[0042] Where k vp For the speed ring proportional parameter; k vi Here are the integral parameters of the speed loop; J is the moment of inertia of the motor, and n is the integral parameter of the speed loop. p τ is the number of pole pairs of the motor; s The electrical time constant; For permanent magnet flux linkage; T s This represents the system sampling time.

[0043] Step 2.5: Establish a bidirectional data link between the Maxwell model and Simulink using the Twinbuilder tool, including the torque transmitted from the Maxwell motor, the motor speed and angle transmitted from the Simulink FMU model, and the load torque transmitted from Adams_sub.

[0044] A further aspect of the present invention is that step 3 is specifically as follows:

[0045] Step 3.1: Create a multibody dynamics model of the motor and an external load model in Adams software. Adams software supports rigid-flexible hybrid modeling and defining the nonlinear stiffness characteristics of spring-damped systems.

[0046] Step 3.2: When exporting the motor model, select FMU as the target software; when exporting the external load model, select Matlab as the target software.

[0047] Step 3.3: Input torque into the FMU model and output the angle and angular velocity of the motor rotor.

[0048] Step 3.4: The Adams_sub model takes the rotor's angle or angular velocity as input and outputs the load torque.

[0049] A further aspect of the present invention is that step 4 is specifically as follows:

[0050] Step 4.1: Call the S-Function module in the Simulink module library. Input the path of the motor AnsysElectroic file from Step 1. The input of S-Function is the external load, and the output is the motor torque.

[0051] Step 4.2: Call the FMU module in the Simulink module library and input the FMU model file path from Step 3.

[0052] Step 4.3: Open the exported Adams folder using Matlab, run the Controls_Plant.m file inside, and enter adams_sys in the command window to call the Adams_sub module.

[0053] Step 4.4: Connect the three modules above in the following order: connect the motor torque output from the S-Function to the input of the FMU; connect the rotor angle or angular velocity output from the FMU to the input of Adams_sub to drive the load mechanism; and connect the output of Adams_sub to the input of the S-Function to transmit the external load torque to the Maxwell motor.

[0054] A further aspect of the present invention is that step 5 is specifically as follows:

[0055] The time step for each software component is set to be the same as the total simulation time, with the time step ranging from 10μs to 100μs. Shorter simulation steps result in more accurate results. Simulink is used as the main control program to perform co-simulation. Cross-platform data exchange is achieved among the software components through shared memory.

[0056] Beneficial effects

[0057] The beneficial effects of this invention are:

[0058] First, the co-simulation method for permanent magnet synchronous motors of the present invention, compared with traditional single-physics simulation, truly reflects the coupling effect between various physical fields under complex working conditions, and can avoid the errors and omissions caused by single simulation.

[0059] Secondly, the co-simulation method for permanent magnet synchronous motors of the present invention, compared with the traditional co-simulation, enables the motor to sense sudden load changes through real-time interaction of electromagnetic, circuit and mechanism fields. Then, the motor torque and current are quickly adjusted by the PI controller, which solves the problems of unrealistic external load and abnormal load detection in engineering practice, and realizes the leap from "ideal load" to "actual load".

[0060] Third, the present invention provides a co-simulation method for permanent magnet synchronous motors, which significantly shortens the simulation time by using the FMU / Adams_sub standardized interface and reducing the order of the motor model. Attached Figure Description

[0061] Figure 1 This is a flowchart of a co-simulation of a permanent magnet motor according to the present invention.

[0062] Figure 2 This is a schematic diagram of the finite element model of the motor provided in Embodiment 1 of the present invention.

[0063] Figure 3 This is the motor circuit control diagram provided in Embodiment 1 of the present invention.

[0064] Figure 4 This is a multibody dynamics model diagram of the Adams motor provided in Embodiment 1 of the present invention.

[0065] Figure 5 This is a diagram of the external load model of the Adams motor provided in Embodiment 1 of the present invention.

[0066] Figure 6 This is a diagram of the Simulink co-simulation platform provided in Embodiment 1 of the present invention.

[0067] Figure 7 This is the motor torque simulation result curve provided in Embodiment 1 of the present invention.

[0068] Figure 8 This is the motor current simulation result curve provided in Embodiment 1 of the present invention.

[0069] Figure 9 This is the motor speed simulation result curve provided in Embodiment 1 of the present invention.

[0070] Figure 10 The curve is the simulation result curve of the external load torque of the Adams motor provided in Embodiment 1 of the present invention.

[0071] Figure 11 This is a comparison chart of the motor torque simulation result curve provided in Embodiment 1 of the present invention and the torque simulation result curve of the traditional motor joint simulation.

[0072] Figure 12 The current simulation result curve is obtained by using traditional co-simulation of motor current.

[0073] Figure 13 The result curve of motor speed simulation is obtained by using traditional co-simulation.

[0074] Figure 14 The curves are simulation results of external load on the motor using traditional co-simulation.

[0075] Figure 15 This is a diagram of an abnormal external load model for a motor provided in Embodiment 2 of the present invention.

[0076] Figure 16 This is the motor abnormal load simulation torque result curve provided in Embodiment 2 of the present invention.

[0077] Figure 17 This is the simulation current result curve of abnormal load on the motor provided in Embodiment 2 of the present invention.

[0078] Figure 18 This is the motor abnormal load simulation speed result curve provided in Embodiment 2 of the present invention.

[0079] Figure 19 This is the simulation result curve of the external abnormal load torque of the Adams motor provided in Embodiment 2 of the present invention.

[0080] Figure 20 This is a schematic diagram of the control circuit in step 2 of the present invention. Detailed Implementation

[0081] The present invention will be further described below with reference to specific embodiments.

[0082] Example 1:

[0083] like Figure 1 As shown, the detailed steps of this embodiment are as follows:

[0084] I. Motor parameters are shown in Table 1 below. A finite element model of the permanent magnet synchronous motor is established in Maxwell. Material nonlinear characteristics and motion boundary conditions are defined. Then, the motor winding excitation, number of turns, current direction, and boundary conditions are set. The default Votlage option in the excitation settings is changed to External. Parameters are set in the excitation to reduce the motor's order. An adaptive mesh generation strategy is then implemented. Finally, in Design Settings, the reduced-order motor model is allowed to be imported into Simplier via TwinBuilder, as shown below. Figure 2 As shown.

[0085] Table 1. Parameters of Permanent Magnet Synchronous Motor

[0086]

[0087] II. Circuit parameters are shown in Table 2 below. An external circuit for motor control was built in Simplier, and the motor model from Maxwell was imported into the circuit. The external drive uses a three-phase full-bridge inverter circuit, and the motor inverter control method is implemented through the SVPWM module in Simplier. Based on the vector control principle, Park transform module, Clarke transform module, and PI control module were built to complete the regulation of the current loop and speed loop, as shown below. Figure 3 As shown.

[0088] Table 2 Circuit Parameters

[0089]

[0090] 3. Create the multibody dynamics model of the electric motor and the external load model in Adams. Since Adams only considers the dynamics of the electric motor, during modeling, you only need to set the rotor's moment of inertia to be the same as that in the Simplier circuit, such as... Figure 4 As shown. The external load model includes two meshing gears with a transmission ratio of 1:2, a torque of 70 N·m applied to the shaft at 0.4 s, and the collision force generated when the gears rotate. The collision force is generated by the contact force in Adams software, and the collision force index is set to the default of 2.2. Figure 5 As shown.

[0091] Fourth, build a bidirectional data transmission platform in Simulink, including the S-Function module, FMU module, Adams_sub module, etc., and connect them sequentially, such as... Figure 6 As shown.

[0092] V. The simulation time step for each software is 10μs, and the total simulation time is set to 0.6s. The Simulink platform is the main control program, executing the start, pause, or stop of the co-simulation. Cross-platform data exchange is achieved through shared memory among the software programs. Simulation results are as follows: Figure 7-10 As shown, the traditional co-simulation results are as follows: Figure 11-14 As shown.

[0093] Example 2:

[0094] This embodiment is identical to the previous one except for the load modeling step in the third step of embodiment 1. Figure 15 As shown, in this embodiment, the Adams load model uses abnormal load modeling, that is, the meshing of a broken gear and a intact gear as an external load. The simulation results are as follows. Figure 16-19As shown in the results, the current of the permanent magnet synchronous motor remained at 125A and the torque remained above 100N·m. The speed initially increased and reached about 670r / min at 0.25s before decreasing until it reached 0. This indicates that the load had already exceeded the motor's limit and the risk of motor damage was extremely high. This verifies that the method can detect abnormal load mechanisms.

[0095] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A co-simulation method for permanent magnet synchronous motors, characterized in that, Includes the following steps: Step 1: In Maxwell, establish a finite element model of a permanent magnet synchronous motor, define the nonlinear characteristics of the material and the boundary conditions of motion, set the winding excitation, number of turns, and current direction, and check the "Enable transient-transient link with Twin Builder" option in the Design Setting. Step 2: Build the motor drive control circuit in Simplier. Import the finite element model and Simulink module using the Twinbuilder tool to establish an electromagnetic-circuit co-simulation environment and data transmission channel. Step 3: Create the motor multibody dynamics model and external load model in Adams, and export them as FMU format and Adams_sub format respectively; Step 4: Deploy the S-Function module, FMU module, and Adams_sub module in Simulink, and connect them sequentially to form a joint simulation of electromagnetic-circuit-mechanism. Step 5: Simulink is used as the main control program to perform co-simulation. The time step and total time are set to be the same in each software. The shorter the simulation step, the more accurate the result. The software exchanges data across platforms through shared memory.

2. The co-simulation method for permanent magnet synchronous motors as described in claim 1, characterized in that, Step 1 specifically includes: Step 1.1: Establish the transient field model of the motor using the finite element method, draw the motor model, and set the materials of each component of the motor; Step 1.2: Set various parameters for the materials in the material library, such as the BH curve and the demagnetization curve of the permanent magnet; Step 1.3: Implement an adaptive mesh generation strategy to locally refine the mesh in the air gap region; Step 1.4: Set the winding excitation, number of turns, current direction and boundary conditions. Change the default Votlage in the excitation options to External to allow the motor to accept current from the Simplier. Step 1.5: Set parameters in the excitation to reduce the order of the motor. The reduced-order model can speed up the co-simulation process. Step 1.6: In the Design Settings, check the "Enable transient-transient link with Twin Builder" option.

3. The co-simulation method for permanent magnet synchronous motors as described in claim 1, characterized in that, Step 2 involves constructing a motor drive control circuit in Simplier, importing the finite element model using the Twinbuilder tool, and then... id =0 vector control algorithm, establishing an electromagnetic-circuit co-simulation environment, specifically including: Step 2.1: Build an SVPWM space vector pulse width modulation model in Simplier and set the dead time to 1μs~10μs; Step 2.2: Build an inverter circuit in Simplier. The inverter circuit consists of 6 transistors and 6 diodes. Connect the output of the SVPWM space vector pulse width modulation model to it. Step 2.3: Build Park and Clarke conversion modules in Simplier; connect the output terminal of the three-phase current to the input terminal of the Clarke conversion module, and connect the output terminal of the Clarke conversion module to the input terminal of the SVPWM module; Step 2.4: Establish a dual closed-loop system composed of proportional-integral controllers to control the motor speed and current respectively; the PI module is responsible for quickly adjusting the motor torque and current after the motor is subjected to external load, so that the motor can resist the external load. Step 2.5: Establish a bidirectional data link between the Maxwell model and Simulink using the Twinbuilder tool, including the torque transmitted from the Maxwell motor, the motor speed and angle transmitted from the Simulink FMU model, and the load torque transmitted from Adams_sub.

4. The co-simulation method for permanent magnet synchronous motors as described in claim 1, characterized in that, Step 3 specifically includes: Step 3.1: Create a multibody dynamics model of the motor and an external load model in Adams software. Adams software supports rigid-flexible hybrid modeling and defining the nonlinear stiffness characteristics of spring-damped systems. Step 3.2: When exporting the motor model, select FMU as the target software; when exporting the external load model, select Matlab as the target software. Step 3.3: Input torque into the FMU model, and output the angle and angular velocity of the motor rotor; Step 3.4: The Adams_sub model takes the rotor angle or angular velocity as input and outputs the load torque.

5. The co-simulation method for permanent magnet synchronous motors as described in claim 1, characterized in that, Step 4 includes: Step 4.1: Call the S-Function module in the Simulink module library, input the path of the motor AnsysElectroic file in claim 1, the input of S-Function is the external load, and the output is the motor torque; Step 4.2: Call the FMU module in the Simulink module library and input the FMU model file path from claim 3; Step 4.3: Open the exported Adams folder using Matlab, run the Controls_Plant.m file, and enter adams_sys in the command window to call the Adams_sub module; Step 4.4: Connect the above three modules in the following order: connect the motor torque output by S-Function to the input terminal of FMU; connect the rotor angle or angular velocity output by FMU to the input terminal of Adams_sub to drive the load mechanism; connect the output terminal of Adams_sub to the input terminal of S-Function to transmit the external load torque to the Maxwell motor.

6. The co-simulation method for permanent magnet synchronous motors as described in claim 1, characterized in that, The co-simulation employs the following synchronization mechanism: The time step and total simulation time should be set to be the same for all software programs. The time step should be between 10μs and 100μs. The shorter the time step, the more accurate the results. The software programs can exchange data across platforms by sharing memory.

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