ANSYS EMAG

ANSYS, Inc. Proprietary© 2004 ANSYS, Inc.

ANSYS Release 9.0Multiphysics & Electromagnetics

New Features

ANSYS Release 9.0Multiphysics & Electromagnetics

New FeaturesPaul Lethbridge

Product ManagerRev 2


ANSYS Workbench Electromagnetics

ANSYS Workbench Electromagnetics


Contents

Workbench Electromagnetics– Workbench Emag Roadmap– Design Modeler

• Enclosure Symmetry• Winding Bodies• Winding Tool

– Simulation


Workbench Emag Roadmap

• LF Emag capability will be exposed over several release cycles:– 3D Magnetostatics (9.0)– 3D Electrostatics (10.0)– 3D Current conduction– Circuit elements– Time transient & 2D

• Workbench v9.0 is the first release with electromagnetic analysis capability. – Support solid and stranded (wound) conductors– Automated computations of force, torque, inductance, and coil

flux linkage.– Easily set up simulations to compute results as a function of

current, stroke, or rotor angle.

• Workbench Emag capability is mapped to & accessed via:– ANSYS Emag (stand alone or enabled task) – ANSYS Multiphysics license keys.


Workbench Emag Markets

Target markets:• Solenoid actuators• Permanent magnet devices• Sensors• Rotating Electric machines

– Synchronous machines– DC machines– Permanent magnet machines


Contents


• Enclosure Symmetry• Winding bodies• Winding Tool

– Simulation


Enclosure Symmetry

•Feature: The Enclosure feature now supports symmetry models when the enclosure shape is a box or a cylinder:

– Up to 3 three symmetry planes can be specified. – Full or partial models can be included in the Enclosure. – During the model transfer from DesignModeler to Simulation, theenclosure feature with symmetry planes forms two kinds of named selections:

– Open Domain– Symmetry Plane


Contents



– Simulation


Winding Bodies & Tool

• Feature: Design Modeler (DM) includes two new tools to allow a user to easily create current carrying coils:

– Winding Bodies: Used to represent wound coils for source excitation. The advantage of these bodies is that they are not 3D CAD objects, and hence simplify modeling/meshing of winding structures.

– Upon “attach to Simulation”, Winding Bodies are assigned as Conductor bodies.

– Winding Tool: Used to create more complex coils for motor windings. The Winding Tool uses a Worksheet table format to drive the creation of multiply connected Winding Bodies. Or a user can read in a text file created by MSExcel.

• Benefits: Very easy to use, rapid creation of coil windings.


Winding Bodies

A line body can be promoted to a winding body. Turns and cross-section (CS) dimensions are entered

Winding cross-section displayed

Tangent orientation vector (blue arrow) defines direction of current.


Winding Tool

Complex coil windings may be created using the Winding Tool:• The Winding Tool inserts a “Winding#” into the model tree. • A “Details” view is used for geometric placement.


Winding Tool

Each Winding consists a number of related Winding Bodies.The related Winding Bodies are shown in the Parts/Bodies branch:

Winding Bodies


Winding Table File

• Each Winding has a Winding Table File associated with it. • The Winding Table File can be created directly in DM• The Winding Table File can be exported to or imported from a text file.• Each row corresponds to a created Winding Body


Winding Table File

• The Winding Table File can be exported to or imported from a text file.


Winding Tool Example

Winding 1 highlighted with rotor

Complete DC Motor model


Winding Options

• Coils may have different radii between IN & OUT slots• Multiple coils may be stacked in the same slot


Winding Options - Skew

• A skew angle may be identified for the coil winding slots• Many motor designs employ a skewed coil form.


Winding Slot Clash Detection

Winding Tool automatically detects if the coil clashed with another part and warns the user


Contents



– Simulation• Tools Layout• Winding bodies• Material Properties• Air Gap Mesh Sizing• Conductors• Solution


Simulation Tools Layout

Electromagnetic Toolbar

Simulation Environment:•Emag boundary conditions•Conductor source excitation

Solution Results•Field•Force•Torque•Inductance •Flux linkage


Winding Body Transfer in Simulation

Winding bodies are automatically assigned to conductor bodies. From the Winding Tool, each Phase Winding is assigned as a unique conductor.In this example, Conductor A consists of 2 winding bodies.


Material Property Support

Both linear & nonlinear Emag materials are supported by Engineering Data:

• Soft materials (Steel, iron, etc.)– Constant (isotropic)– Laminated (orthotropic)– Linear/nonlinear (single B-H curve)

• Hard materials (NdFeB, SmCo, Alnico)– Linear– Nonlinear


Materials – BH Curves

BH curves with up to 500 data points are supported


Materials - Permanent MagnetsCoordinate systems are used to align the polarization axis of a magnet. Cartesian and Radial Magnetization are supported.


Air Gap Mesh Sizing• Requirement: . In an electromagnetics analysis models

typically include narrow gaps between parts such as rotors and stators. It is important to have a refined mesh in these gaps.

• Feature: Air Gap Mesh sizing. As for other mesh controls, air gaps are assigned under Advanced Controls in the Mesh Detail.

• Benefits: Easy to use mesh refinement, resulting in more accurate analysis results.


Air Gap Mesh Sizing


Conductor Objects identify conductors for excitation, inductance, and Post processing. Can be scoped to solid bodies (solid conductors), or Winding Bodies (wound coils)

Excitation: Supports voltage and current loading for solid conductors. Current and phase angle are supported for Winding Bodies.

Conductor Objects


Solution Results


Vector & Contour Plots

Vector / Contour is selected in the Solution objects “Definition”


Inductance & Flux Linkage

Solution branch can insert Inductance & Flux linkage post processing calculations. Self and mutual inductance is computed.


Parameter Sweeps

The Emag analysis can be fully parameterized so that a user can easily extract force or torque versus rotor position etc.

An example will be available to demonstrate this shortly!


ANSYS Multiphysics ANSYS Multiphysics


Contents

• ANSYS Multiphysics – Thermoelectric Direct Coupled Field– LF Electromagnetics– HF Electromagnetics


• Feature: New thermoelectric analysis option on the series 22X direct coupled-field elements includes: – Seebeck, Peltier, Thomson effects– Transient electrical effects (capacitive “damping”)

• Benefit: Addresses new thermoelectric applications where temperature stabilization, temperature cycling, compact or pinpoint cooling are required.

• Applicable to: PLANE223, SOLID226, SOLID227. Steady-state & transient analysis.

Thermoelectric Analysis


Thermoelectric Elements

PLANE223 SOLID226 SOLID2272-D 8-node 3-D 20-node 3-D 10-node

LoadsSF: CONV, HFLUX, RDSF

BF: HGEN

NameCoupled-field solid

Geometry

Product MP,PP,ED

KEYOPT(1) 110 (thermoelectric analysis)

DOFs-ReactionsTemperature (TEMP) – Heat flow (HEAT)

Electric scalar potential (VOLT) - Electric current (AMPS)

KXX, KYY, RSVX, RSVY, SBKX, SBKY, DENS, C, ENTH, PERX,PERYMaterial

PropertiesKZZ, RSVZ, SBKZ, PERZ

KEYOPT(3)0 - Plane

1-Axisymmetric


Thermocouple example

Voltage distributionTR= 25 ºC

TC= 0 ºC

TH= 100 ºC

Material AMaterial B

Material B

VS= 0.0425 V

Differential junction temperature results in a 42 mV potential difference


Peltier Cooler Example

p-type material(α=230μVolt/ oC)

n-type material(α= -195μVolt/ oC)

Iin= 10 A

conductor

Iout

Cold side T= -3 oC

Hot side T= 54 oC

Temperature distribution:

10A current flow results in a 57oC temperature differential.


Example markets and applications for the thermoelectric analysiscapability:

• Electronic and optical component cooling– CPU, photo-detectors, low noise amplifiers, laser diodes, fiber optics

• Consumer products– Portable food/beverage coolers, automotive seat cooling/heating

• Medical, laboratory and scientific equipment– Blood analyzers, thermal cycling devices (blood, lymph, DNA), portable

insulin coolers, heart and eye surgery, hypothermia blankets

• Military & Space– Night vision equipment, guidance systems, pilot suit temperature regulation

• Indoor environmental devices– Conditioners, fans, humidifiers

Markets and Applications


Contents

• ANSYS Multiphysics – Direct Coupled Field– LF Electromagnetics

• Electromagnetic forces & torque• Conductance Matrix

– HF Electromagnetics


Electromagnetic Force & Torque

• Feature: New command and underlying numerical (Virtual Work force) calculation to summarize electromagnetic force and torque.

• Command: EMFT• Benefit: Easier to use, faster, & more

accurate.Electric and magnetic methodology are now the same – consistency.

• Applicable to: SOLID117, PLANE121, SOLID122, SOLID123.


Electromagnetic Forces – 2D

Potential distribution

Electrostatic forces

Electrostatic Forces, 2D MEMS comb drive example


Electromagnetic Forces – 2D

gVN

xWF r

t

20

argεε

=∂∂

=

Electrostatic Force (N)

Driving (x) Transverse (y)

Simplified analytical [1,2](Ignores fringing effects)

5.31⋅10-9 0.0

ANSYS (Maxwell Stress Tensor)

3.55⋅10-9 0.006⋅10-9

ANSYS (New Virtual Work)

5.65⋅10-9 0.005⋅10-9

REFERENCES

1. T.-C. H. Nguyen W.C. Tang and R.T. Howe. Laterally driven polysilicon resonant microstructures. Sensors and Actuators A, 20:25–32, 1989.

2. M.W. Judy W.C. Tang, T.-C.H. Nguyen and R.T. Howe. Electrostatic-comb drive of lateral polysilicon resonators. Sensors and Actuators A, 21-23:328–331, 1990.

MEMS comb drive example results:


Electromagnetic Forces- 3D

1/8th symmetry Potential distribution

Electrostatic forces

Half symmetry problem description

Concentric sphere verification benchmark:


Electromagnetic Forces- 3D

Concentric sphere results:

REFERENCES

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capsph.html#c1

Radial Electrostatic Force (N)

Fa (inner) Fb (outer)

Analytical model2.23⋅10-6 -0.56⋅10-6

ANSYS (Maxwell Stress Tensor)

1.59⋅10-6 -0.79⋅10-6

ANSYS (New Virtual Work)

2.21⋅10-6 -0.55⋅10-6

22

20

112

⎥⎦⎤

⎢⎣⎡ −

=∂∂

=

baa

VaWF r

aεπε

22

20

112

⎥⎦⎤

⎢⎣⎡ −

−=∂∂

=

bab

VbWF r

bεπε


Electromagnetic forces – 3D

TEAM20 Solenoid Benchmark Results:

Vertical (z-direction) force (N)1000 A-turns 3000 A-turns 5000 A-turns

Experimental (target) 8.10 54.4 80.1

ANSYS (Old Virtual Work) 7.24 51.3 76.7

ANSYS (New Virtual Work) 7.25 51.4 76.8

REFERENCES

1. M. Gyimesi, D. F. Ostergaard, “Analysis of Benchmark Problem TEAM20 with Various Formulations”, Proceedings of TEAM Workshop, COMPUMAG, Rio, 1997.

2. M. Gyimesi, D. F. Ostergaard, “Mixed Shape Non-Conforming Edge Elements”, IEEE Transactions on Magnetics, Vol. 35 No. 3, 1999, pp. 1407-1409.

3. M. Gyimesi, D. F. Ostergaard, “Non-Conforming Hexahedral Edge Elements for Magnetic Analysis”, IEEE Transactions on Magnetics, Vol 34 No. 5, 1998, pp. 2481-2484.

See also new Verification Example: VM241.


Conductance Matrix

• Feature: A new macro is now available to extract conductance from multi-conductor systems. This macro, which is used much like the CMATRIX macro for capacitance, allows you to extract self and mutual conductance terms so that equivalent circuit lumped conductors can be defined for use in circuit simulators.

• Command: GMATRIX• Benefit: Provides improved lumped parameter connectivity with

circuit simulators. Combined with CMATRIX, and LMATRIX, a user can now extract L, C & G matrices for subsequent use circuit simulators.

• Applicable to:–SOLID5,PLANE67,LINK68,SOLID69,SOLID98–PLANE230,SOLID231,SOLID232–Not available with Trefftz method.


Contents

• ANSYS Multiphysics – Direct Coupled Field– LF Electromagnetics– HF Electromagnetics

Frequency Selective SurfacesLumped CircuitsFast Frequency Sweep VTSPICE sub-circuit extraction (Beta)Smith ChartsSpecific Absorption Rate (SAR)Multi-port Power Calculation


Frequency Selective Surfaces• Features:

–To compliment the Floquet periodic boundary condition (released at 8.1), a plane wave source port (via HFPORT) is now available to launch a plane wave for a scattering analysis of a periodic structure. Such a structure is commonly referred to as a Frequency Selective Surface (FSS).–Radar Cross Section (RCS) results can be displayed and listed for 2D TE and TM incident plane waves (via PLHFFAR and PRHFFAR). –FSS Reflection and transmission properties are calculated using the new FSSPARM macro.

• Benefit: A new capability introduced to address a growing market need to analyze FSS.

• Applicable to: HF119, HF120.(Hex, Tet, Wedge and Pyramid) & PML.

Incident Plane Wave

Periodic Structure


Frequency Selective SurfacesFSS example: Plane wave incident at 45o

ϕ=90°

θ=45°

x

y

z

E-Field (x) Contours

Far field pattern


Lumped HF Circuit Elements

• Feature: HF Lumped “RLC” circuit elements. They are applied to the mid-nodes of element edges using the BF command.

• Benefit: A new capability that can be used to greatly simplify a HF analysis in a similar manner to our LF Emag circuit elements. The lumped circuit greatly reduces the number of DOF’s.

• Application: Use to simulate passive devices like resistors, or to simplify a structure when fringe effects at discontinuities can be ignored.

• Applicable to: HF119, HF120 (Hex, Tet, Wedge and Pyramid).

Microstrip line

FEA Domain (Mesh)

Lumped RLC circuit model


Lumped HF Circuit Elements

• Command: BF, <Node>, Lump, <value1>

• Six types of lumped circuits are available, value1 of the BF command is used to specify which :

– Complex impedance – Shunt RCL circuit – Series RL with shunt C – Series RCL – Series RC with shunt L – Series LC with shunt R


SPICE Sub-circuit Extraction

• Feature: SPICE Compatible Sub-circuit Extraction. Feature synthesizes an RLCG equivalent circuit for passive multi-port electromagnetic structure.

• Commands: SPICE

• Benefit: Ability to easily connect ANSYS to system level EDA circuit simulation tools for signal integrity applications. Allows ANSYS to start to address high frequency time domain analysis. Extracted circuit is SPICE compatible.

• Usage: SPICE sub circuit is extracted from S-parameter frequency sweep.

• Applicable to: HF119, HF120.(Hex, Tet, Wedge and Pyramid). S parameter extraction only.

9.0 BETA


3rd Party EDA Signal Integrity

tool suite

ANSYS Multiphysics

SPICE Sub-circuit Extraction

Integrating ANSYS HF Emag into Signal Integrity Process Flow:

Parametric GeometryCreation

HF Emag solver

S-parameter sweep

SPICE circuit extraction

SPICE simulation

Time Transient Waveforms

Design Rules

9.0 BETA


Fast Frequency Sweep VT• Feature: The fast Frequency Sweep VT module has been enhanced

using a perfect absorber. This provides a 20% faster solution than the original VT method.

• Commands: SPSWP, HROPT

• Benefit: Fast S-parameter calculations over a wide frequency range.

• Usage: Frequency Sweep VT is an additional charge module that can be added to ANSYS Multiphysics.

• Applicable to: HF119, HF120.(Hex, Tet, Wedge and Pyramid). S parameter extraction only.

0

0.2

0.4

0.6

0.8

1

10

10.4

10.7

11.1

11.4

11.8

12.1

12.5

12.8

13.2

13.5

13.9

14.2

14.6

14.9

15.3

15.6 16

16.3

16.7 17

17.4

17.7

18.1

18.4

18.8

19.1

19.5

19.8

Frequency (GHz)

|S11

|


Smith Chart & Network Parameters

• Features:– Conversion of scattering (S), admittance (Y) or impedance (Z)

parameters for display on a Smith Chart.– Display the required network parameters and generate a new

Touchstone file for the required parameter. – Plot the required network parameters as the response of the

frequency on an x-y graph. • Commands: PLSCH, PLSYZ, PRSYZ• Benefit: Ability to display results in formats that are widely accepted in

the industry. Easier for RF engineers to understand ANSYS results! • Applicable to: HF119, HF120.(Hex, Tet, Wedge and Pyramid).


Smith Chart & Network Parameters


Specific Absorption Rate (SAR)

Features: Specific Absorption Rate (SAR) Calculation for lossy materials. Can plot or list SAR distribution using ETABLE of ANSYS postprocessor.

Commands: SAR is calculated when a mass density of the material is defined by the MP command. Results are stored in the HF119 and HF120 Item and Sequence Numbers Table.

Benefit: Ability to compute SAR is an important capability required for primarily biomedical studies of effects of HF energy on living tissue.

Applicable to: HF119, HF120.(Hex, Tet, Wedge and Pyramid).


Multi-Port Power Calculation

Feature: Power Calculation for Multi-port High-Frequency networks. Feature provides:

• Input/Output power at ports• Dissipated power in multi-port system• Power reflection/transmission coefficient• Return loss and insertion loss at ports

Command: HFPOWER

Benefit: Ability to compute SAR is an important capability required for primarily biomedical studies of effects of HF energy on living tissue.

Applicable to: HF119, HF120.(Hex, Tet, Wedge and Pyramid).


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