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Ansoft Maxwell Field Simulator V12 – Training Manual P1-1
Permanent Magnet Synchronous Machine
0.00 0.20 0.40 0.60 0.80 1.00Norm alizedDis tance
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
1.20
Bra
dial
Ansoft Corporation PMSM_CTXY Plot 2Curve Info
BradialSetup1 : TransientTime='0ns'
0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00Time [s]
-3.00
-2.00
-1.00
0.00
1.00
2.00
3.00
Y1 [N
ewto
nMet
er]
Ansoft Corporation PMSM_CT_VerifyCogging Torque
0.1402
2.2271
0.43540.5877
MX2: 5.4031MX1: 0.6379
Curve Info
Optimized DesignSetup1 : Transient
Moving1.TorqueImported Nominal Design
0.00 2.00 4.00 6.00 8.00 10.00Time [ms]
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0.20
0.40
0.60
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Cor
eLos
s [k
W]
Ansoft Corporation PMSM_OC_EMFCore Loss
Curve InfoCoreLoss
Setup1 : Transient
0.00 2.00 4.00 6.00 8.00 10.00Time [ms]
-150.00
-100.00
-50.00
0.00
50.00
100.00
150.00
Y1 [V
]
Ansoft Corporation PMSM_OC_EMFXY Plot 2
Curve Info
InducedVoltage(PhaseA)Setup1 : Transient
InducedVoltage(PhaseB)Setup1 : Transient
InducedVoltage(PhaseC)Setup1 : Transient
Ansoft Maxwell Field Simulator V12 – Training Manual P1-2
Permanent Magnet Synchronous Machine: Contents
RMxprtBasic Theory
Review Example
Add Unique Winding Arrangement
Setup Parametric Problem
Export Design to Maxwell 2D
Maxwell: Cogging TorqueReview Maxwell Setup
Create Variables
Apply Mesh Operations
Solve Nominal Problem
Setup Optimization Problem
Review Pre-Solved Optimization Results
Maxwell: Open Circuit Back EMFDefine Material Core Loss Characteristics
Set Lamination and Stack Factor
Consider Power Loss in Magnets
Solve Problem and Review Results
Maxwell: Rated Condition – Functional Voltage Source
Modify Rotor Geometry using UDP’s
Winding Setup Definitions and Variable Definition
Choosing Optimal Time Step
Solve Problem and Review Results
Drive DesignCreate a Machine Model
Use the Model in Circuit Simulation
Notes:
1. RMxprt/Maxwell V12 or higher is required
2. Basic knowledge of electric machine is required
3. Basic understanding of Finite Element is required
Ansoft Maxwell Field Simulator V12 – Training Manual P1-3
Electric Machine Design Suite
A Complete Solution for Modern Electric Machines and Drives Design
Equivalent Circuit Model : High Fidelity Physics Based Model
Fast Analytical Solution: Narrow the Design Space
Parametric AnalysisOptimization
Magnetostatic/Eddy Current Analysis using FEA
Parametric AnalysisOptimization
AHAJA ×∇×+×∇+∇−∂∂−=×∇×∇ vV
t cs σσσυ
scf
ff
ff uu
dtid
LiRddtdA
aSlN
d =+++Ω∫∫ 0=−dt
duCi cf
Field Equation:
Circuit Equation:
Motion Equationexternalem TTm +=+λωα
Simultaneous Equations:
Transient Analysis using FEA
Parametric Analysis
A_PHASE_N1
A_PHASE_N2
B_PHASE_N1
B_PHASE_N2
C_PHASE_N1
C_PHASE_N2
ROTB1
ROTB2
EMSSLink1
EMF2
RA
RB
RC
A
IA
A
IB
A
IC
1750.023
0.023
0.023
theta>90 AND theta<150theta>150 AND theta<210
theta>210 AND theta<270
theta>270 AND theta<330theta>330 OR theta<30
ICA:
theta>30 AND theta<90
EMF1 175
E1
R1
E2
R2
E3
R3
E4
R4
E5
R5
E6
R6
ctrl_1:=OFFctrl_6:=OFF
ctrl_1:=ON
ctrl_6:=ONctrl_1:=ONctrl_2:=ON
ctrl_1:=OFFctrl_2:=OFF
ctrl_2:=ONctrl_3:=ON
ctrl_2:=OFF
ctrl_3:=ONctrl_4:=ON
ctrl_4:=ONctrl_5:=ON
ctrl_5:=ON
ctrl_6:=ON
ctrl_5:=OFFctrl_6:=OFF
ctrl_3:=OFF
ctrl_3:=OFFctrl_4:=OFF
ctrl_4:=OFFctrl_5:=OFF
A AM_IGBT
+ VVBC
+ VVGE4
MASS_ROTB1
Drive System Integration with Manufacturer’s IGBTs
EMF
A
IA
A
IB
A
IC
175
ICA:
EMF 175
A AM_IGB
V+ VVBC
A_PHASE_N1
B_PHASE_N1
C_PHASE_N1
ROT1
ROT2
ECE
ECELink
T
FM_ROT
PP:=
ON:=
OFF:=
THRESH:=4
HYST:=
EQU theta_elect := PP * ECELink
theta := MOD(theta_elect
ωω+IGBT
IGBT IGBT
IGBTIGBT
D2 D3
Drive System using System Level IGBT’s and Analytical Motor Model
Phase CurreIAIBIC
t
1.00
-1.00
0
-500.0
500.0
0 17.27m10.00m
TorquTo
t
400.0
-100.0
0
200.0
0 17.2710.00
Phase VoltagV_A
t
300.0
-300.0
0
-200.0
200.0
0 17.2710.00
Von Mises stress
Thermal and Stress Analysis
A_PHASE_N1
A_PHASE_N2
B_PHASE_N1
B_PHASE_N2
C_PHASE_N1
C_PHASE_N2
ROTB1
ROTB2
EMSSLink1
EMF2
RA
RB
RC
A
IA
A
IB
A
IC
1750.023
0.023
0.023
theta>90 AND theta<150theta>150 AND theta<210
theta>210 AND theta<270
theta>270 AND theta<330theta>330 OR theta<30
ICA:
theta>30 AND theta<90
EMF1 175
E1
R1
E2
R2
E3
R3
E4
R4
E5
R5
E6
R6
ctrl_1:=OFFctrl_6:=OFF
ctrl_1:=ON
ctrl_6:=ONctrl_1:=ONctrl_2:=ON
ctrl_1:=OFFctrl_2:=OFF
ctrl_2:=ONctrl_3:=ON
ctrl_2:=OFF
ctrl_3:=ONctrl_4:=ON
ctrl_4:=ONctrl_5:=ON
ctrl_5:=ON
ctrl_6:=ON
ctrl_5:=OFFctrl_6:=OFF
ctrl_3:=OFF
ctrl_3:=OFFctrl_4:=OFF
ctrl_4:=OFFctrl_5:=OFF
A AM_IGBT
+ VVBC
+ VVGE4
MASS_ROTB1
Complete Transient FEA -Transient System Co-simulation
Design Requirements
Size/Weight EfficiencyTorqueSpeedCogging/RippleInverter MatchingThermalStressManufacturabilityCost
Ansoft Maxwell Field Simulator V12 – Training Manual P1-4
RMxprt: Background
ASSM: Adjustable-Speed Synchronous MachineRotor speed is controlled by adjusting the frequency of the input voltage
Unlike brushless PMDC motors, ASSM does not utilize the position sensors.
Rotor can be either inner or outer type
Can operate as a generator or as a motorMotor Mode:
Sinusoidal AC source
DC source via a DC to AC inverter
Generator Mode:Supplies an AC source for electric loads
Ansoft Maxwell Field Simulator V12 – Training Manual P1-5
ASSM: Background
Input voltage U is the reference phasor, let the angle I lags U be φ, the power factor angle
Let the angle I lags E0 be ψ. The d- and the q-axis currents can be obtained respectively as follows:
ϕ−∠= II
=
=
ψψ
cossin
III
q
dI
q
d1
II−= tanψ
Ansoft Maxwell Field Simulator V12 – Training Manual P1-6
ASSM: Background
OM can be used to determine the direction of E0
Let the angle E0 lags U be θ, which is called the torque angle for the motor, then the angle ψ is
For a given torque angle θ :
Solving for Id and Iq yields:
)jj( aq11 XXROM ++−= IU
θϕψ −=
−
−=
− θ
θsin
cosU
EUII
XRRX 0
q
d
q1
1d
−−+−
+=
θθθθ
sin)cos(sin)cos(
UXEURUREUX
XXR1
II
d01
10q
qd21q
d
Ansoft Maxwell Field Simulator V12 – Training Manual P1-7
ASSM: Background
The power factor angle φ is
The Input electric power is
The Output mechanical power is
Pfw : Frictional and Wind Loss
PCua: Armature Copper Loss
PFe : Iron-core Loss
Torque:
Efficiency:
θψϕ +=
ϕcos31 UIP =
)(12 FeCuafw PPPPP ++−=
ω2
2PT =
%100PP
1
2 ×=η
Ansoft Maxwell Field Simulator V12 – Training Manual P1-8
RMxprt: Base Project
Open the RMxprt project located on your desktop by double clicking on PM_SyncMotor.mxwl
Save the project under a new name:File > Save As > c:\Training\PM_SyncMotor.mxwl
Select Setup1 under Analysis and click the Right Mouse Button (RMB) and Choose Analyze
Ansoft Maxwell Field Simulator V12 – Training Manual P1-9
RMxprt: Results
Select Setup1, click the RMB and choose Performance
Choose a Solution Set
Ansoft Maxwell Field Simulator V12 – Training Manual P1-10
RMxprt: Results
Select Setup1, click the RMB and choose Performance
Choose a Performance Curve
Ansoft Maxwell Field Simulator V12 – Training Manual P1-11
RMxprt: Add New Winding Arrangement
1
2
3
Double click on Stator > WindingClick on Whole-CoiledSelect Editor
Ansoft Maxwell Field Simulator V12 – Training Manual P1-12
RMxprt: Add New Winding Arrangement
In the Winding Editor Panel, click the RMB and select Edit Layout
Deselect Constant PitchChange the Layout as shown
Ansoft Maxwell Field Simulator V12 – Training Manual P1-13
RMxprt: Add New Winding Arrangement
View the new winding arrangement by placing the mouse over one of the A phase coils in the drawing window and click the RMB selecting Connect One Phase Coils.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-14
RMxprt: Performance
Solve the problem by selecting Setup1 under Analysis and click the Right Mouse Button (RMB) and Choose AnalyzeSelect Setup1, click the RMB and choose Performance
Ansoft Maxwell Field Simulator V12 – Training Manual P1-15
RMxprt: Add Variables
Click on Winding and in the Properties window, next to Conductors PerSlot type in CPS
Click on Stator and in the Properties window, next to Length type in Depth
1
2
1
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-16
RMxprt: Add Variables
Click on Rotor and in the Properties window, next to Length type in Depth
Select menu item RMxprt > Optimetrics Analysis > Add Parametrics
Ansoft Maxwell Field Simulator V12 – Training Manual P1-17
RMxprt: Parametric Setup
Click on Add and setup the two variables as follows:
Click on the Calculations Tab > Setup Calculations and add the followingCurrent > RMSLineCurrentParameter
Power > OutputPowerParameter
Misc. > EfficiencyParameter
1
2
3
4
Ansoft Maxwell Field Simulator V12 – Training Manual P1-18
RMxprt: Parametric Solution
Select ParametricSetup1 under Optimetrics, click the RMB and Analyze
Select ParametricsSetup1, click RMB and select View Analysis ResultsSelect Table and then click on Efficiency Parameter
Efficiency increased from 89% to over 98% while maintaining output power
Ansoft Maxwell Field Simulator V12 – Training Manual P1-19
RMxprt: Create Maxwell Design
Select Setup1, click the RMB and select Create Maxwell Design
2
deselect
Choose
4
1
3
Ansoft Maxwell Field Simulator V12 – Training Manual P1-20
Maxwell 2D: Base Design
Material Assignment
Motion
Boundaries
Winding
Mesh
Results
Soln. Setup
Ansoft Maxwell Field Simulator V12 – Training Manual P1-21
Maxwell 2D: Cogging Torque, Excitation
Select the PhaseA winding, click the RMB and select PropertiesChange the Type to Current with a value of zero
Repeat this for PhaseB and PhaseC
Ansoft Maxwell Field Simulator V12 – Training Manual P1-22
Maxwell 2D: Cogging Torque, Mesh Ops
Select Length_Magnet under Mesh Operations, click the RMB and select Properties
Decrease the size of the element by half. Just type in 3.75/2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-23
Maxwell 2D: Cogging Torque, Mesh Ops.
Select Length_Main under Mesh Operations, RMB and select Properties
Decrease the size of the element by 4. Just type in 10.96/4
Ansoft Maxwell Field Simulator V12 – Training Manual P1-24
Maxwell 2D: Cogging Torque, Mesh Ops.
Select SurfApprox_Mag under Mesh Operations, RMB and select Properties
Decrease the length of the “Maximum Surface Deviation” to 190 nm. This yields an angular segmentation of Θ = 0.25 deg.
))2/cos(1( Θ−= rDr is the inside radius of the stator which is 81mm
Ansoft Maxwell Field Simulator V12 – Training Manual P1-25
Maxwell 2D: Cogging Torque, Mesh Ops.
Select SurfApprox_Main under Mesh Operations, RMB and select Properties
Decrease the length of the “Maximum Surface Deviation” to 190 nm
Ansoft Maxwell Field Simulator V12 – Training Manual P1-26
Maxwell 2D: Cogging Torque, Mesh Ops.
Three possible operations:
D D = Maximum Surface Deviation
ro
ri
SFoAspectRati
DSFro
ri
DrShapeFactoro
ri
1
)3(*3
)2(*2
=
=
=1
AR=2
Θ
))2/cos(1( Θ−= rD
rΘ = Maximum Surface
Normal Deviation
2
Aspect Ratio of Cells,not of triangles
Ansoft Maxwell Field Simulator V12 – Training Manual P1-27
Maxwell 2D: Cogging Torque, Mesh Ops.
Select Band in the modeler tree, RMB and select Properties
Decrease the SegAngle value to 0.25 degrees
NOTE!: This small value for angular segmentation, 0.25deg, is neededonly for very sensitive calculations such as Cogging Torque
Ansoft Maxwell Field Simulator V12 – Training Manual P1-28
Maxwell 2D: Cogging Torque, Mechanical Setup
Select Motion Setup1 under Model, RMB to select PropertiesSelect Mechanical Tab and change speed to 1 deg/sec
Select Setup1 under Analysis and RMB to select Properties
Ansoft Maxwell Field Simulator V12 – Training Manual P1-29
Maxwell 2D: Cogging Torque, Solution Setup
Change to Save Fields tab
31
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-30
Maxwell 2D: Cogging torque, Results
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-3.00
-2.00
-1.00
0.00
1.00
2.00
3.00
Mov
ing1
.Tor
que
[New
tonM
eter
]
Ansoft Corporation Maxwell2DDesign1Torque
Curve Info
Moving1.TorqueSetup1 : Transient
Since the speed is held constant at 1.0 deg/sec, the X-Axis represents both time and position, i.e. 10 sec = 10 deg
Solve the cogging torque problem by selecting Setup1 under Analysis, RMB and select Analyze:
Once the problem is solved double click on Results > Torque
Click the RMB in the plot and select Export Data. Save the plot on the desktop.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-31
Maxwell 2D: Cogging torque, Results
Select menu item View > Set Solution Context, and choose zero seconds.
In the drawing window hit
CTRL+A to select all objects,
RMB to select Fields > A >Flux_Lines
Ansoft Maxwell Field Simulator V12 – Training Manual P1-32
Maxwell 2D: Cogging torque, Results
Double Click on Legend to change plot properties
Ansoft Maxwell Field Simulator V12 – Training Manual P1-33
Maxwell 2D: Cogging torque, Results
Select Flux_Lines1 under A under Field Overlays, RMB to select Animate
Ansoft Maxwell Field Simulator V12 – Training Manual P1-34
Maxwell 2D: Cogging torque, Rename Design
Rename Maxwell2DDesign1 by selecting its name in the project tree, RMB and select Rename. Change the name to PMSM_CT for Permanent Magnet Synchronous Motor Cogging Torque.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-35
Maxwell 2D: Cogging torque, Variables
Select CreateUserDefinedPart under Mag_0 under NdFe30_N and choose Properties
1
2
3
In the Value field type in the name PoleEmbrace
Ansoft Maxwell Field Simulator V12 – Training Manual P1-36
Maxwell 2D: Cogging Torque, Optimization Variables
Change the field for the ThickMag to MagnetThickness and accept the default value of 7.5mm
1
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-37
Maxwell 2D: Cogging Torque, Optimization Variables
Change the field for the Offset to PoleOffset and accept the default value of 0mm.
1
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-38
Maxwell 2D: Cogging Torque, Optimization Variables
Select CreateUserDefinedPart under InnerRegion under Vacuum and choose Properties
In the Value field type in the names: PoleEmbraceMagnetThicknessPoleOffset
1
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-39
Maxwell 2D: Cogging Torque, Optimization Variables
Select CreateUserDefinedPart under Rotor under M19_26G_SF0.950 and choose Properties
In the Value field type in the names: PoleEmbraceMagnetThicknessPoleOffset
1
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-40
Maxwell 2D: Cogging Torque, Optimization Variables
Select menu item Maxwell 2D > Design Properties and change the value of the variables just defined:
Select the Optimization radio button and Include each variable:
Ansoft Maxwell Field Simulator V12 – Training Manual P1-41
Maxwell 2D: Cogging Torque, Optimization Variables
Modify the variable to see the effect on the geometry
Pole Offset
PE
MT
For this exercise, the range for each is:6.5 mm < MagnetThickness < 9.5 mm0.6 < PoleEmbrace < 0.90 < PoleOffset < 30 mm
Ansoft Maxwell Field Simulator V12 – Training Manual P1-42
Maxwell 2D: Cogging Torque Optimization, Air Gap Arc
Create an arc in the air gap to be used for post processing purposes, by selecting menu item Draw > Arc > Center Point
Using the mouse select the origin, any point in the air gap along the X axis and any point in the air gap at the 45 degree angle. Any value used if valid, it will be modified in the next step.
1
2
3Double click to end
Ansoft Maxwell Field Simulator V12 – Training Manual P1-43
Maxwell 2D: Cogging Torque Optimization, Air Gap Arc
Select CreateAngularArc under CreatePolyline under Polyline1 under Lines, RMB and select Properties
Change the value for the starting point to 80.8, 0, 0. This will place the arc between the band object and the stator ID
Select Polyline1. In the Properties window change its name to AG_Arc
Ansoft Maxwell Field Simulator V12 – Training Manual P1-44
Maxwell 2D: Cogging Torque Optimization, Variables
Select menu item Maxwell 2D > Field > CalculatorPerform the following commands to calculate the radial component of the flux density in the air gap
Quantity > B
Scal? > Scalar X
Function > PHI
Trig > cos
Multiply *
Quantity > B
Scal? > Scalar Y
Function > PHI
Trig > sin
Multiply *
Add + -- this gives Bx*cos(PHI) + By*sin(PHI)
Add … > Name: Bradial -- this adds the express to the stack
Ansoft Maxwell Field Simulator V12 – Training Manual P1-45
Maxwell 2D: Cogging Torque Optimization, Variables
Continue to calculate the average radial component of the air gap flux density
Select Bradial under Named Expressions
Copy to Stack
Geometry > Line > AG_Arc
Integrate
Number > Scalar > Value = 1
Geometry > Line > AG_Arc
Integrate
Divide / -- this give the average radial flux density in the air gap
Add … > Name: Brad_Avg -- this adds this expression to the stack
Ansoft Maxwell Field Simulator V12 – Training Manual P1-46
Maxwell 2D: Cogging Torque Optimization, Variables
Continue to calculate the area of the permanent magnetNumber > Scalar > Value = 1
Geometry > Surface > Mag_0
Integrate
Number > Scalar > Value = 1e6 -- this converts from m2 to mm2
Multiply *
Add … > Mag_Area -- this adds this expression to the stack
Select the Maxwell 2D Design PMSM_CT and in the Properties window change the variables back to their default values
Even though the design variables and thus the geometry has changed, once the design variables are set to their previous values, the solution is automatically reloaded; there is no need to solve the problem again.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-47
Maxwell 2D: Cogging Torque Optimization, Variables
Plot the radial flux density in the air gap by selecting Results, RMB to select Create Field Report > Rectangular Plot
Ansoft Maxwell Field Simulator V12 – Training Manual P1-48
Maxwell 2D: Cogging Torque Optimization, Brad AG
Plot B_rad on the AG_Arc
2
3
4
5
7
10
1
6
8 9
Ansoft Maxwell Field Simulator V12 – Training Manual P1-49
Maxwell 2D: Cogging Torque Optimization, Brad AG
Plot of B radial in air gap at time zero
0.00 0.20 0.40 0.60 0.80 1.00Norm alizedDis tance
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
1.20
Bra
dial
Ansoft Corporation PMSM_CTXY Plot 2Curve Info
BradialSetup1 : TransientTime='0ns'
Click the RMB in the plot window and select Export Data. Save the plot on the desktop.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-50
Optimization: Solution Setup
Change the Stop Time of the Simulation from 15 seconds to 3.75 sec. The cogging torque waveform is symmetric after 3.75 deg (equal to 3.75 sec) and to save simulation time we only need to solve up to this point.
Select Setup1 under Analysis and RMB to select Properties
Ansoft Maxwell Field Simulator V12 – Training Manual P1-51
Maxwell 2D: Cogging Torque Optimization, Variables
Select Optimetrics and RMB to select Add > Optimization
Next to Optimizer select Genetic Algorithm
Ansoft Maxwell Field Simulator V12 – Training Manual P1-52
Maxwell 2D: Cogging Torque Optimization Setup
Click on Setup
Change the values as shown here
Ansoft Maxwell Field Simulator V12 – Training Manual P1-53
Maxwell 2D: Cogging Torque Optimization Setup
Cogging Torque Peak Nominal Value* = 2.2 N-mMaximum Value** = 5.5 N-m
Optimal Goal = 0.2 N-m (subjectively chosen, we want to reduce CT by >10x)
Normalize Solution Range: 1 to 10G1 = 1 + (max(abs(Torque)) – 0.2) * 9 / 5.3
Objective: G1 = 1.0
*Note: The Peak Nominal Value is when:MagnetThickness = 7.5 mmPoleEmbrace = 0.85PoleOffset = 0 mm
**Note: The Maximum Value is determined when these values are a Maximum:MagnetThickness = 9.5 mmPoleEmbrace = 0.90PoleOffset = 0 mm
The maximum value of cogging torque may lay outside these parameter values, i.esomewhere else in the solution domain. These values are used just to define a range for the objective.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-54
Maxwell 2D: Cogging Torque Optimization Setup
Nominal Bavg Value = 0.76 TeslaRange*: 0.50 < Bavg < 0.81 Tesla Optimal Goal = 0.76 Tesla (we want to maintain the Air Gap Flux Density)Normalize Range: 1 to 10
G2 = 1 + (Brad_Avg – 0.5) * 9 / 0.31Objective: G2 = 8.55
Magnet AreaRange*: 220 < Mag_area < 510 mm2
Normalize Range: 1 to 10G3 = 1 + (Mag_area – 220) * 9 / 290Objective: G3 = 1.0
*Note: The Range was calculated by simulation the minimum and maximum values:MagnetThickness … 6.5 mm and 9.5 mmPoleEmbrace … 0.6 and 0.9PoleOffset .. 0 mm and 30 mm
Ansoft Maxwell Field Simulator V12 – Training Manual P1-55
Maxwell 2D: Cogging Torque Optimization Setup
In the Calculation Expression field type in the function as shown below
1 2 3
4
5
Ansoft Maxwell Field Simulator V12 – Training Manual P1-56
Maxwell 2D: Cogging Torque Optimization Setup
Include Calculation for the average radial component of the flux density in the air gap
Type in the rest of the expression and then click on Add Calculation
2 3 4
1
5
Ansoft Maxwell Field Simulator V12 – Training Manual P1-57
Maxwell 2D: Cogging Torque Optimization Setup
Include calculation for Magnet Area
Type in the rest of the expression and then click on Add Calculation
1
2 3
4
Ansoft Maxwell Field Simulator V12 – Training Manual P1-58
Maxwell 2D: Cogging Torque Optimization Setup
For the calculation expressions for Brad_Avg and Mag_Area click on Calc. Range and select 0ns for time zero
1
3
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-59
Maxwell 2D: Cogging Torque Optimization Setup
Set the Goal and Weigh for each objective
Cost1 = (G1 – 0.2)2 * W1 where G1 = max(abs(Torque))
Cost2 = (G2 – 0.75)2 * W2 where G2 = abs(AirGap_Bavg)
Cost3 = (G3 – 230)2 * W3 where G3 = Mag_area
Cost = Cost1+Cost2+Cost3
Note: The Cogging Torque and Air Gap Flux Density have equal weight, which is twice that of the magnet area
Ansoft Maxwell Field Simulator V12 – Training Manual P1-60
Maxwell 2D: Cogging Torque Optimization Setup
Click on the Variables tab and change the values accordingly:
This problem takes too long to solve during the class. The full solution can be downloaded from Ansoft’s FTP site:
ftp://ftp.ansoft.com/download/ChinaTraining/PM_SyncMotor_Opt.zip
To solve the problem, select OptimizationSetup1 under Optimetrics, RMB and select Analyze
Ansoft Maxwell Field Simulator V12 – Training Manual P1-61
Maxwell 2D: Cogging Torque Optimization Results
Ansoft Maxwell Field Simulator V12 – Training Manual P1-62
Maxwell 2D: Cogging Torque Optimization Setup
Since the field solution was not saved for each variation in theoptimization solution, create a second Maxwell 2D design and solve the problem with the optimized design variable values.
Select the Maxwell 2D design PMSM_CT, RMB and select Copy
Select the project name PM_SyncMotor, RMB and select Paste
Select the Maxwell 2D design PMSM_CT1, RMB and select Rename, and change the design name to PMSM_CT_Verify
Ansoft Maxwell Field Simulator V12 – Training Manual P1-63
Maxwell 2D: Cogging Torque Optimization Verify
Select the design PMSM_CT_Verify and in the Properties window change the design variables to the Optimized value
Increase the Stop Time to 7.5 sec and then solve the design:
1 2
3
Ansoft Maxwell Field Simulator V12 – Training Manual P1-64
Maxwell 2D: Cogging Torque Optimization Verify
Plot the Cogging Torque
0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00Time [s]
-0.50
-0.40
-0.30
-0.20
-0.10
0.00
0.10
0.20
0.30
0.40
0.50
Opt
imiz
ed D
esig
n [N
ewto
nMet
er]
Ansoft Corporation PMSM_CT_VerifyCogging TorqueCurve Info
Optimized DesignSetup1 : Transient
Ansoft Maxwell Field Simulator V12 – Training Manual P1-65
Maxwell 2D: Cogging Torque Optimization Verify
In the plot window RMB to select Import Data and pick the cogging torque plot that was exported earlier.
0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00Time [s]
-3.00
-2.00
-1.00
0.00
1.00
2.00
3.00
Y1
[New
tonM
eter
]
Ansoft Corporation PMSM_CT_VerifyCogging Torque
0.1402
2.2271
0.43540.5877
MX2: 5.4031MX1: 0.6379
Curve Info
Optimized DesignSetup1 : Transient
Moving1.TorqueImported Nominal Design In plot window, RMB
and select Marker > Add X Marker
Optimized Design
Nominal Design
Ansoft Maxwell Field Simulator V12 – Training Manual P1-66
Maxwell 2D: Cogging Torque Optimization Verify
Plot the air gap flux density
0.00 0.20 0.40 0.60 0.80 1.00NormalizedDistance
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
1.20
Brad
ial
Ansoft Corporation PMSM_CT_VerifyAir Gap Flux Density
Curve Info
BradialSetup1 : TransientTime='0ns'
Ansoft Maxwell Field Simulator V12 – Training Manual P1-67
Maxwell 2D: AG Flux Density
In the plot window RMB to select Import Data and pick the Air Gap flux density plot that was exported earlier.
0.00 0.20 0.40 0.60 0.80 1.00NormalizedDistance
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
1.20
Bra
dial
Ansoft Corporation PMSM_CT_VerifyAir Gap Flux Density
Curve Info
BradialSetup1 : TransientTime='0ns'
BradialImported Nominal Design
Ansoft Maxwell Field Simulator V12 – Training Manual P1-68
Maxwell 2D: AG Flux Density
Determine the average air gap flux density.
3
4The target optimized value is 0.76T
1
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-69
Maxwell 2D: Magnet Area
Determine the magnet area.
21
The area of the magnet for the nominal design was 383 mm2
3
Ansoft Maxwell Field Simulator V12 – Training Manual P1-70
Maxwell 2D: Open Circuit Back EMF
Select the design PMSM_CT_Verify, RMB and select Copy
Select the project PM_SyncMotor, RMB and select Paste
Select the new design PMSM_CT_Verify1, RMB and select Rename. Change the name to PMSM_OC_EMF
Ansoft Maxwell Field Simulator V12 – Training Manual P1-71
Maxwell 2D: Open Circuit Back EMF
Select MotionSetup1 under Model, RMB to select Properties
Select the Mechanical tab and change the speed to 3600 rpm
Ansoft Maxwell Field Simulator V12 – Training Manual P1-72
Maxwell 2D: Open Circuit Back EMF, Core Loss Setup
Calculate the core loss coefficients from multiple core loss curves
Ansoft Maxwell Field Simulator V12 – Training Manual P1-73
Maxwell 2D: Open Circuit Back EMF, Core Loss Setup
Select the Stator and in the Properties widow click on the material M19_26G_SF0.950 and then select View/Edit Material
1
3
2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-74
Maxwell 2D: Open Circuit Back EMF, Core Loss Setup
Add the core loss curve for 60Hz
1
2
3 Choose the file M470-65A-60Hz.tab4
5
Ansoft Maxwell Field Simulator V12 – Training Manual P1-75
Maxwell 2D: Open Circuit Back EMF, Core Loss Setup
Add the core loss curve for 100Hz
1
2
3 Choose the file M470-65A-100Hz.tab4
5
Ansoft Maxwell Field Simulator V12 – Training Manual P1-76
Maxwell 2D: Open Circuit Back EMF, Core Loss Setup
Continue to add the following curves:M470-65A-200Hz.tab M470-65A-400Hz.tab
M470-65A-600Hz.tab M470-65A-700Hz.tab M470-65A-1kHz.tab
Ansoft Maxwell Field Simulator V12 – Training Manual P1-77
Maxwell 2D: Open Circuit Back EMF, Magnet Loss
Select Mag_0 and in the Properties next to Materials click on NdFe30_N and then on View/Edit Materials.
Change the conductivity to 625000 S/m
Material properties are global quantities, the affect all designs. Thus when modifying materials that are common to various designs, thesolutions to the designs become invalid.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-78
Maxwell 2D: Open Circuit Back EMF, Magnet Loss
Select Mag_0, RMB to select Assign Excitation > Current
By assigning zero current to the magnet it is assured that total current into and out of this magnet is zero. If there were more than one magnet, each one should have a separate excitation of zero amps.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-79
Maxwell 2D: Open Circuit Back EMF, Magnet Loss
Select Excitations, RMB to select Set Eddy Effect
Ansoft Maxwell Field Simulator V12 – Training Manual P1-80
Maxwell 2D: Open Circuit Back EMF, Core Loss
Select Excitations, RMB to select Set Core Loss. Add Core Loss for the Rotor and Stator
Ansoft Maxwell Field Simulator V12 – Training Manual P1-81
Maxwell 2D: Open Circuit Back EMF, Solution Setup
Modify the solution setup by selecting Setup1, RMB and select Properties
1
2
The time step is determined by:
sec3.46deg1
secdeg21600
sec60min1*deg360*
min3600
urevrev
==
The frequency is 240 Hz, which gives a period of 4.2 msec. Thus 10 msec is ~2.5 cycles
Ansoft Maxwell Field Simulator V12 – Training Manual P1-82
Maxwell 2D: Open Circuit Back EMF, Results
Solve the transient problem by selecting Setup1 under Analysis, RMB to select Analyze
After the problem is solved, click on Results, RMB to select Create Transient Report > Rectangular Plot
1
23
Ansoft Maxwell Field Simulator V12 – Training Manual P1-83
Maxwell 2D: Open Circuit Back EMF, Results
0.00 2.00 4.00 6.00 8.00 10.00Time [ms]
-150.00
-100.00
-50.00
0.00
50.00
100.00
150.00Y
1 [V
]
Ansoft Corporation PMSM_OC_EMFXY Plot 2
Curve Info
InducedVoltage(PhaseA)Setup1 : Transient
InducedVoltage(PhaseB)Setup1 : Transient
InducedVoltage(PhaseC)Setup1 : Transient
Ansoft Maxwell Field Simulator V12 – Training Manual P1-84
Maxwell 2D: Open Circuit Back EMF, Results
Click on Results, RMB to select Create Transient Report > Rectangular Plot
12
3
Ansoft Maxwell Field Simulator V12 – Training Manual P1-85
Maxwell 2D: Open Circuit Back EMF, Results
0.00 2.00 4.00 6.00 8.00 10.00Time [ms]
0.00
0.20
0.40
0.60
0.80
1.00
1.20C
oreL
oss
[kW
]
Ansoft Corporation PMSM_OC_EMFCore Loss
Curve InfoCoreLoss
Setup1 : Transient
Ansoft Maxwell Field Simulator V12 – Training Manual P1-86
Maxwell 2D: Rated Condition
To solve the problem for the rated condition, select the Maxwell 2D design PMSM_OC_EMF, RMB and select CopySelect the project name PM_SyncMotor, RMB and select Paste
Select the Maxwell 2D design PMSM_OC_EMF1, RMB and select Rename, and change the design name to PMSM_Rated
Delete the Mag_0, Rotor,and InnerRegion
Ansoft Maxwell Field Simulator V12 – Training Manual P1-87
Maxwell 2D: New Rotor Geometry
Select menu item Draw > User Defined Primitive > SysLib > RMxrpt > IPMCore. Modify the Values as shown below.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-88
Maxwell 2D: New Rotor Geometry
Select the object IPMCore1 and then Edit > Arrange > Rotate
Select Modeler > Boolean > Split
Select Edit > Arrange > Rotate and use -45 degrees about the Z axisSelect Modeler > Boolean > Split in the XZ Plane Keeping Fragments on the Negative SideSelect Edit > Arrange > Rotate and use +45 degrees about the Z axis
Ansoft Maxwell Field Simulator V12 – Training Manual P1-89
Maxwell 2D: New Rotor Geometry
Select IPMCore1 and in the Properties windowName: Rotor
Material: M19_26G_SF0.950
Select Rotor, RMB to select Edit > CopyIn the drawing window, RMB to select Edit > PasteSelect CreateUserDefinedPart under Rotor1, RMB to select Properties
Change InfoCore to 1
Select Rotor1 and then Maxwell Model > Boolean > Separate Bodies. This will create two magnets. Change the name of the magnets to Mag_0 and Mag_1and change their color.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-90
Maxwell 2D: New Rotor Geometry
Select Rotor, RMB to select Edit > CopyIn the drawing window, RMB to select Edit > PasteSelect CreateUserDefinedPart under Rotor1, RMB to select Properties
Change InfoCore to 2
Select Rotor1 and in the Properties windowName: Duct
Material: Vacuum
Ansoft Maxwell Field Simulator V12 – Training Manual P1-91
Maxwell 2D: Rated Condition, PM Setup
Select Mag_0 and in the Properties window click on the material M19_26G_SF0.950 and select NdFe30 and then Clone Material(s)
1
2
3
Ansoft Maxwell Field Simulator V12 – Training Manual P1-92
Maxwell 2D: Rated Condition, PM Setup
Change the name to NdFe30_NV for North Pole V Core
Repeat the same for Mag_1
Cartesian CS with the pole aligned with the X axis
Ansoft Maxwell Field Simulator V12 – Training Manual P1-93
Maxwell 2D: Rated Condition, PM Setup
The drawing tree should look like this
Ansoft Maxwell Field Simulator V12 – Training Manual P1-94
Maxwell 2D: Rated Condition, PM Setup
A local coordinate system needs to be create for each magnet. Zoom into Mag_0. Select the Create Relative CS Icon
2
3
1
A local CS is create with X and Y axis as shown. Magnetization will be along the X axis4
Ansoft Maxwell Field Simulator V12 – Training Manual P1-95
Maxwell 2D: Rated Condition, PM Setup
Zoom into Mag_1. Select the Create Relative CS Icon
3
1
2
A local CS is create with X and Y axis as shown. Magnetization will be along the X axis4
Ansoft Maxwell Field Simulator V12 – Training Manual P1-96
Maxwell 2D: Rated Condition, PM Setup
Select Mag_0 and in the Properties Window change Orientation to RelateiveCS1
Select Mag_1 and in the Properties Window change Orientation to RelateiveCS2
Ansoft Maxwell Field Simulator V12 – Training Manual P1-97
Maxwell 2D: Rated Condition, PM Mesh Ops.
Select Mag_0 and Mag_1, RMB to assign mesh operations
Ansoft Maxwell Field Simulator V12 – Training Manual P1-98
Maxwell 2D: Rated Condition, Excitation
Select Rotor, Mag_0, Mag_1, and Duct. Select Moving1 under Motion, RMB to select Add Selected Object
Select PhaseA under Excitations, RMB to select Properties
163.299 * sin(2*pi*240*time+18.2635*pi/180)
Ansoft Maxwell Field Simulator V12 – Training Manual P1-99
Maxwell 2D: Rated Condition, Excitation
Select PhaseB and then PhaseC under Excitations, RMB to select Properties.
VB = 163.299 * sin(2*pi*240*time+18.2635*pi/180-2*pi/3)VC = 163.299 * sin(2*pi*240*time+18.2635*pi/180-4*pi/3)
Ansoft Maxwell Field Simulator V12 – Training Manual P1-100
Maxwell 2D: Rated Condition, Excitation
Select Excitation, RMB to select Setup Y Connection
2
3
1
Ansoft Maxwell Field Simulator V12 – Training Manual P1-101
Maxwell 2D: Rated Condition, Solution Setup
Select MotionSetup1 under Model, RMB to select Properties and then Data to change the Initial Position, and then Mechanical to set the speed
Select Setup1 under Analysis, RMB and select Properties
This problem takes too long to solve during the class. The full solution can be downloaded from Ansoft’s FTP site:
ftp://ftp.ansoft.com/download/ChinaTraining/PM_SyncMotor_Rated.zip
Ansoft Maxwell Field Simulator V12 – Training Manual P1-102
Maxwell 2D: Rated Condition, Results
0.00 50.00 100.00Time [ms]
-100.00
0.00
100.00
200.00
300.00
400.00
500.00
600.00
Mov
ing1
.Tor
que
[New
tonM
eter
]
Ansoft Corporation PMSM_RatedTorque Quick ReportCurve Info
Moving1.TorqueSetup1 : Transient
0.00 50.00 100.00Time [ms]
-4000.00
-3000.00
-2000.00
-1000.00
0.00
1000.00
2000.00
3000.00
Y1
[A]
Ansoft Corporation PMSM_RatedWinding Currents
Curve Info
Current(PhaseA)Setup1 : Transient
Current(PhaseB)Setup1 : Transient
Current(PhaseC)Setup1 : Transient
85.00 87.50 90.00 92.50 95.00 97.50 100.00Time [ms]
1.20
1.30
1.40
1.50
1.60
1.70
1.80
1.90
Cor
eLos
s [k
W]
Ansoft Corporation PMSM_RatedCore LossCurve Info
CoreLossSetup1 : Transient
Ansoft Maxwell Field Simulator V12 – Training Manual P1-103
Simplorer: Drive Design
1. Create Permanent Magnet Synchronous Machine Model from RMxprt:
Double click on the original RMxprt design, click on menu RMxprt > Analysis Setup > Export …,choose “Simplorer Model” from the list and select a path where you want the model to be saved.
2. View the text of the model: Run Simplorer V7.0.5, in “SSC 7.0 Commander” window, click on Programs > Editor, open the model file we just created from RMxprt(*.sml).
Note: The model is not simply a linear model you can typically find from a textbook any more. It has nonlinear effect considered for both main and leakage flux magnetic paths. This model can also be used as both motor and generator.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-104
Simplorer: Drive Design
3. Use the RMxprt created model in Simplorer as a generator:
Open a new Simplorer Schematic, click on the “Add Ons” tab of the “ModelAgent”, click on “interfaces”, drag and drop “RMxprt” component on the schematic.
Double click on the “RMxprtLink1” and then click on “Import Model (*.sml)”, browse to the locationwhere the model was saved. Select the model > Open > OK, you should have the model show up like the following graph, with electrical nodes on the left and mechanical nodes on the right.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-105
Simplorer: Drive Design
4. Build the rest of the schematic like below. Details of each component are shown on the next page.
RMXABC
ROT1ROT2
RMxprtLink1
ω+
V_ROT1
0
92.00
50.00
0 40.00m20.00m
DC Link Voltage
R_Load.V [V]
B6U
D1D3D5
D2D4D6
B6U1
R_Load C1
+ V VM1
-94.00
84.00
-50.00
0
50.00
0 40.00m20.00m
Back EMF (A-B
VM1.V [V]
0
2.00k
1.00k
0 40.00m20.00m
Input Speed from Shaft
V_ROT1.OMEGA [rpm]
-362.00
-3.55f
-300.00
-200.00
-100.00
0 40.00m20.00m
Rotor Position (Deg
RMxprtLink1.Pos
C := 1u
R := 1k
VALUE := 1000*(1+(t>0.02))
Ansoft Maxwell Field Simulator V12 – Training Manual P1-106
Simplorer: Drive Design
5. ModelAgent > Add Ons tab > power > Line-commutated Converters > B6 Diode Bridge
Ansoft Maxwell Field Simulator V12 – Training Manual P1-107
Simplorer: Drive Design
6. ModelAgent > Basics tab > Measurement > Electrical > Voltmeter
7. ModelAgent > Basics tab > Circuit > Passive Elements > Resistor and Capacitor
Note: Select the component and right mouse click to Flip or Rotate the component. Or you can use quick shortcut “F’ for Flip and “R” for Rotate.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-108
Simplorer: Drive Design
8. ModelAgent > Basics tab > Physical Domains > Mechanical > Velocity-Force-Representation > Rotational_V > Angular Velocity Source
Ansoft Maxwell Field Simulator V12 – Training Manual P1-109
Simplorer: Drive Design
9. Click on Simulation > Parameters, or Alt + F12, or just double mouse click on any empty space on the schematic, define simulation parameters as seen from the picture.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-110
Simplorer: Drive Design
10. ModelAgent > Displays tab > Displays > 2D View
Create plots of R_Load.V, VM1.V, RMxprtLink1.Pos, V_ROT1.OMEGA (rpm).
11. Run the simulation and view the results.
Ansoft Maxwell Field Simulator V12 – Training Manual P1-111
This completes the one day training course on permanent magnet
synchronous machines using Ansoft’sRMxprt, Maxwell 2D and Simplorer