Magnetic Gear Optimization with Ansys Maxwell and Ansys OptiSLang

PADT’s Kang Li shows how Ansys Maxwell can be driven by Ansys OptiSLang to optimize the design of a magnetic gear. This is a great example of connecting an Ansys solver to OptiSLang.

Ansys Maxwell Loss Calculations in a Magnetic Gear

In this video, PADT’s Kang Li shows how to carry out loss calculations from permanent magnets and the core materials.

ANSYS Maxwell: Building a Magnetic Gear Model

In this video, PADT’s Kang Li steps users through the process of building and running a magnetic gear from scratch in Ansys Maxwell. The model shows both standard magnets and a Halbach array.

Simulating Electrical Windings: Solid or Stranded?

In Ansys Maxwell, windings can be added in Eddy Current and Transient Solvers. There are two types of conductors when assigning the windings: Solid and Stranded. What is the difference?

The Solid type considers the conductor as a solid part and therefore, the eddy current and AC effects will be taken into consideration. While the Stranded type assumes the conductor consists of infinite strands of tiny conductors and therefore, there is no eddy current inside the conductor.

Now if there is no time-varying current or magnetic field in the model, will it be the same using Solid or Stranded? The answer is NO. Figure 1 shows a simple geometry of one-turn copper conductor. The cross-section is 1 mm by 1 mm and length of each edge is 100 mm. Assume the winding type is External and the circuit is shown below in Figure 2. The winding is connected to an external resistance (0.003 ohm) and the DC voltage source is 1 V.

The question will be: what is the current in the winding? Based on the physical geometry of the conductor, the conductor resistance can be calculated by R=ρ L/A, where L is the length of the conductor, A is the cross-sectional area and ρ is the resistivity of the copper material. The calculated conductor resistance is about 0.006872 ohm. The winding current will be different based on conductor type.

• Solid type

When the conductor is selected as Solid in ANSYS Maxwell, the winding resistance will be included while calculating the current. Therefore, the winding current will be:

Note: if the winding resistance is changing, the winding current will also change.

And the winding loss will be:

The winding loss calculated by Ansys Maxwell is 70.57 W which is identical to the result above.

• Stranded type

When the conductor is selected as Stranded in Ansys Maxwell, the winding resistance will NOT be included while calculating the current. Therefore, the winding current will be:

Note: the winding current is a constant no matter the winding resistance changes or not.

And the winding loss will be:

The winding loss calculated by Ansys Maxwell is 763.55 W which is identical to the result above.

Conclusion

1. The Solid type is needed if the AC effect is of interest.
2. For Voltage winding type, the DC winding current and DC winding loss will be different for Solid and Stranded types. If the load resistance is much larger/smaller than the winding resistance, this difference can be neglected.
3. If the user is using the Voltage source and doing the EM-Thermal coupling simulation, it requires more attention as the temperature rise will increase the winding resistance and therefore, decrease the winding current (as the voltage is fixed). In this case, users can either choose Solid or add an additional scaling factor in the material property to compensate for the current difference.

Ansys – Software for Electric Machine Design

The electric propulsion system has drawn more and more attention in the last decade. There has been a lot of development of the electric machines which are used in automotive and aerospace. It is essential for engineers to develop electric machines with high efficiency, high power-density, low noise and cost.

Therefore, simulation tools are needed to design the electric machines that can meet the requirement. The product launching time can be reduced significantly with the help of the simulation tools. The design process of electric machine involves the area of Electromagnetics, Mechanical, Thermal and Fluids. This makes Ansys the perfect tool for designing electric machines as it is a multi-physics simulation platform. Ansys offers a complete workflow from electromagnetics to thermal and mechanical which provides accurate and robust designs for electric machines.

To design high performance, more compact and reliable electric machines, design engineers can start with three Ansys tools: RMxprt, Maxwell and Motor-CAD. The capabilities and differences of these three tools will be compared and discussed.

1. Ansys RMxprt

Ansys RMxprt is a template-based tool for electromagnetic designs of electric machines. It covers almost all of the conventional radial types of electric machines. Starting from Ansys 2020R2, some axial types have also been included in RMxprt (IM, PMSM, BLDC).

Users only need to input the geometry parameters and materials for the machines. The performance data and curves can be obtained for different load types. Since RMxprt uses analytical approaches, it can generate results very fast. It is also capable of running fast coupling/system simulations with Simplorer/Twin Builder. Ready-to-run Maxwell 2D/3D models can be created directly from RMxprt automatically.

2. Ansys Maxwell

Ansys Maxwell is a FEA simulation tool for low-frequency electromagnetic applications. Maxwell can solve static, frequency-domain and time-varying electromagnetic and electric fields. The Maxwell applications can be but not limited to electric machines, transformers, sensors, wireless charging, busbars, biomedical, etc.

Unlike RMxprt which uses analytical method, Maxwell uses the FEA approach which allows it to do high accuracy field simulations. Engineers can either import the geometry or create their own models in Maxwell. Therefore, there is no limit of types of machines that can be modeled in Maxwell. It can model all types of electromagnetic rotary devices such as multi-rotor and multi-stator designs.

Maxwell can do more detailed electromagnetic simulations for electric machines, for example, the demagnetization of the permanent magnets, end winding simulations and magnetostrictive effects. With Maxwell, engineers are able to run parametric sweep for different design variables and to do optimizations to achieve the optimal design. Maxwell is also capable of creating equivalent circuit extraction (ECE) models. The ECE is one of the reduced order modelling (ROM) techniques, which automatically generates an efficient system-level model. There are several Ansys customization toolkit (ACT) available for Maxwell to quickly create efficiency map and simulate impact of eccentricity. Furthermore, Maxwell can be coupled with Ansys Mechanical/Fluent/Icepak to do thermal and mechanical analysis.

Ansys Motor-CAD is suitable to make design decisions in early design phase of electric machines. It includes four modules: electromagnetic, thermal, lab and mechanical. Motor-CAD can perform multiphysics simulations of electric machines across the full torque-speed range. Motor-CAD uses a combination of analytical method and FEA, and it can quickly evaluate motor topologies and optimize designs in terms of performance, efficiency and size.

Motor-CAD is capable of simulating the radial types of electric machines. With its lab module, it can do the duty cycle simulations to analyze electromagnetic, mechanical and thermal performances of electric machines. The thermal module is a standard tool in industry which can provide fast thermal analysis with insight of each thermal node, pressure drop, losses. Motor-CAD mechanical module uses 2D FEA to calculate the stress and deformation. Engineers can also manually correlate the models in Motor-CAD based on the manufacturing impacts or testing data.

Motor-CAD can provide links to Ansys Maxwell, Mechanical, Icepak and Fluent for more detailed analysis in the later phases of motor designs.

• What to use?

RMxprt and Motor-CAD both can handle most of the radial types of electric machines. RMxprt can also model some conventional axial flux machines. RMxprt can purely model the electromagnetic performance of the machines, while Motor-CAD can simulate electromagnetic, thermal and mechanical performances.

Maxwell can simulate any types of machines (radial, axial, linear, hybrid, etc.) as it can import or draw any geometry. Both static and transient analysis can be conducted in Maxwell.

• When to use?

RMxprt and Motor-CAD are most suitable in the early design stages of the electric machines. Engineers can get fast results about the machine performance and sizing which can be used as a guideline in the later design phase.

Maxwell can be used in the early design stages for more advanced types of electric machines as well. Maxwell is also capable of doing more detailed electromagnetic designs in the later stage and can be used to do system-level transient-transient co-simulation (coupled with Ansys Simplorer/Twin Builder). More detailed geometries, advanced materials and complex electromagnetic phenomenon can be modeled in Maxwell. In the final stages of running more advanced CFD and NVH analysis, Maxwell can be linked with Ansys Fluent/Icepak/Mechanical to ensure the design robustness of the machines before going into prototyping/production.

• Who can benefit?

RMxprt and Motor-CAD do not require strong FEA simulation skills as no boundary conditions or solution domain need to be set. Engineers with basic knowledge of electric machines can get familiar with the tools and get results very quickly.

Maxwell requires users to setup the mesh, boundary and excitations as it uses the FEA method. Engineers will need to acquire not only the basic concepts of machines but also some FEA simulation skills in order to get more reasonable results.

Summary

RMxprt: It is a template-based tool for initial electric machine designs which uses analytical analysis approach.

Maxwell: It uses FEA approach model both 2D and 3D models. It is capable of simulating either simple or mode advanced electromagnetics in electric machines.

Motor-CAD: It is suitable for initial machine designs which uses analytical and FEA methods. It can do electromagnetic, thermal and initial mechanical analysis.

Windows Update KB4571756 Triggers Error 3221227010 for Ansys Electronics Products

On September 7, 2020 Microsoft released a Windows update KB4571756, which may cause the Ansys electronic products to fail with the Error:

``3221227010 at ‘reg_ansysedt.exe’ and ‘reg_siwave.exe’ registration.``

This is the error message, users would see if they right-mouse-click and run the following file as administrator:

``C:\Program Files\AnsysEM\AnsysEM20.2\Win64\config\ConfigureThisMachine.exe``

To resolve this issue, here are the steps we recommend users take:

1. If the issue is not resolved or something your IT won’t let you do, continue to the next steps.
2. Set an environment variable that turns off the driver that is causing the error.
1. Use windows search and type “system environment” and click on “Edit the system environment variables”
2. This opens the “System Properties” tool
3. Go to the “Advanced” tab
4. Click on “Environment Variables…” at the bottom
5. In the System Variables window click on “New…”
6. Create the following variable:

Variable Value: 1
7. Click OK 3 times to exit out of the tool and save your changes.
3. If the issue is still not resolved, there is one more step:
1. Go to C:\Program Files\AnsysEM\AnsysEM20.2\Win64\config\
2. Right-Mouse-Click on “ConfigureThisMachine.exe” and run as Admin.

If these steps helped to resolve the issue, you will see the following info message when ‘ConfigureThisMachine.exe’ is run:

Video Tips – Two-way connection between Solidworks and ANSYS HFSS

This video will show you how you can set up a two-way connection between Solidworks and ANSYS HFSS so you can modify dimensions as you are iterating through designs from within HFSS itself. This prevents the need for creating several different CAD model iterations within Solidworks and allows a more seamless workflow.  Note that this process also works for the other ANSYS Electromagnetic tools such as ANSYS Maxwell.

ANSYS 17.2 Executable Paths on Linux

When running on a machine with a Linux operating system, it is not uncommon for users to want to run from the command line or with a shell script. To do this you need to know where the actual executable files are located. Based on a request from a customer, we have tried to coalesce the major ANSYS product executables that can be run via command line on Linux into a single list:

ANSYS Workbench (Includes ANSYS Mechanical, Fluent, CFX, Polyflow, Icepak, Autodyn, Composite PrepPost, DesignXplorer, DesignModeler, etc.):

/ansys_inc/v172/Framework/bin/Linux64/runwb2

ANSYS Mechanical APDL, a.k.a. ANSYS ‘classic’:

/ansys_inc/v172/ansys/bin/launcher172 (brings up the MAPDL launcher menu)
/ansys_inc/v172/ansys/bin/mapdl (launches ANSYS MAPDL)

CFX Standalone:

/ansys_inc/v172/CFX/bin/cfx5

Autodyn Standalone:

/ansys_inc/v172/autodyn/bin/autodyn172

Note: A required argument for Autodyn is –I {ident-name}

Fluent Standalone (Fluent Launcher):

/ansys_inc/v172/fluent/bin/fluent

Icepak Standalone:

/ansys_inc/v172/Icepak/bin/icepak

Polyflow Standalone:

/ansys_inc/v172/polyflow/bin/polyflow/polyflow < my.dat

Chemkin:

/ansys_inc/v172/reaction/chemkinpro.linuxx8664/bin/chemkinpro_setup.ksh

Forte:

/ansys_inc/v172/reaction/forte.linuxx8664/bin/forte.sh

TGRID:

/ansys_inc/v172/tgrid/bin/tgrid

ANSYS Electronics Desktop (for Ansoft tools, e.g. Maxwell, HFSS)

/ansys_inc/v172/AnsysEM/AnsysEM17.2/Linux64/ansysedt

SIWave:

/ansys_inc/v172/AnsysEM/AnsysEM17.2/Linux64/siwave