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Presentation - Component Subsystem and System Solutions with Ansoft Software
2001 2002 Worldwide
Road
Show
Mark Christini, Senior Application Engineer Solenoids and Actuators
2D, 3D Electromechanical
System Simulation Simplorer model of
electromechanical actuation Simplorer model of
electromechanical actuation Electromechanical setup of
2D transient analysis
Fast acting
solenoid
Driving circuit Global and local field
results for detailed analysis Magnetic MEMS Position
Sensor
Study of a position sensor in an external
magnetic field Magnetic MEMS Position
Sensor
Fields along the longitudinal axis Magnetic MEMS
Field magnitude on target
Theta = 0
The
ta =
2.5

o Electrostatic MEMS
Actuators
!
For a given distribution of voltages and
various positions of the rotor find:
!
Charge on armatures
!
Torque characteristic
!
Electric energy
!
Force distribution on the rotor Electrostatic MEMS
Actuator
V1
V2
Ground Electrostatic MEMS
Actuator
Rotor
Left armature Right armature
Charge distribution Electrostatic MEMS
Levitation Device
Position
Current Hall Effect Sensor
Target wheel
Permanent magnet
assembly
Permanent magnet
Pole piece
Hall sensor
IC How does it work?
Field in permanent magnet
& pole piece
Field in IC and
Hall sensor Variable reluctance sensor
Permanent magnet
Coil
Pole piece Electro-mechanical
equivalent setup
Coil resistance
Finite element models
(equivalent circuit)
speed
angle
Output voltage VR Sensor Simplorer Results Bus bar system solution
B6C
B6C1
M
DCM
P
MchRDcmp1
~
3PHAS
~
~
A * sin (2 * pi * f * t + PHI + phi_u)
PHI = 0°
PHI = -120°
PHI = -240°
THREE_PHASE1
Bus bar system Bus bar system analysis
Maxwell 3D finite
element model
Equivalent circuit System level analysis of the
bus bar system
Inductance matrix
exported to Simplorer
and/or Maxwell Spice System level model and
results (Maxwell Spice) Simplorer model & results
N_7
N_6
N_5
N_4
N_3
N_2
N_1
EMSS - LINK
EMSS - LINK
EMSSLin
I1
R1
R2
R3
Simplorer model
of bus bas system
Bus bar currents Thermal analysis of the bus
bar system Component Design:
AC Circuit
Breaker Design
Overview
!
Frequency Domain (AC)
analysis consists of time -
dependant vector quantities
!
Design of devices like motors,
generators, transformers and
switches are based on
quadratic quantities such as:
magnetic and electric energies,
power losses, and forces
!
These quantities consist of a
time-averaged DC component
and an alternating component
!
A designer can study the
behavior by knowing the lower
and upper bounds of these
quantities
frequency
nominal
twice
at
oscillates
Force
:
Note
density
flux
magnetic
B
density
current
J
:
where
)
t
(2
cos
F
F
t at
B
J
Force
AC
DC
=
=
+
+
=
×
= The Challenge:
!
Setup and solve AC current
flow problem with multiple paths
!
Consider proximity effects
!
Determine instantaneous force
acting on interrupting contacts
I(c) = 50kA at 240 deg.
I(b) = 50kA at 120 deg.
I(a) = 50kA at 0 deg.
Component Design:
AC Circuit
Breaker Design The Result:
!
Current splits in
parallel paths
based on AC
resistance
!
Skin and
proximity effects
are considered
!
Current
migrates
towards
conductors with
opposite current
flowing
Component Design:
AC Circuit
Breaker Design The Result:
!
Wizard calculates Lorentz
force in any direction
!
Automatically creates plot of
DC, AC and Instantaneous
force vs. time
AC
DC
INST
AC
DC
F
F
F
t
at
dV
B
J
F
dV
B
J
al
F
+
=
×
=
×
=
2
1
Re
2
1
Component Design:
AC Circuit
Breaker Design The Challenge:
!
Analyze complicated
insulation system of oil
and pressboard collars
!
Determine areas of high
electric field stress
Component Design:
Insulation
System Design The Result:
!
Peak E-field plotted on surface of
insulation
!
In areas exceeding dielectric
withstand, clearance increased so as
to decrease maximum E-field
Component Design:
Insulation
System Design Component Design:
Insulation
System Design
The Challenge:
!
Determine peak E-field
!
Determine cumulative stress along
creep path
HV
Ph A
HV
Ph B
LV
Ph B
TV
Ph B
Core
LV
Ph A
TV
Ph A
Pressboard Insulation System for
Oil-filled transformer
Oil The Result:
!
Voltage contours between windings
!
Reduced E-field observed in pressboard collars
!
Peak E-field occurs on corners of static plate
Component Design:
Insulation
System Design
Voltage Plot
E-field Plot The Result:
!
Peak electric field stress (V/m)
!
Using Post 2D macro, can perform Creep Stress Analysis to
determine cumulative stress along line vs. allowable withstand
Component Design:
Insulation
System Design
Critical path
for creep stress
line1 Transformer Simulation
3D Transient with Schematic
Three phase power transformer
Rectifier Circuit
FEA internally coupled
with circuit elements
Coupled with external circuits using Schematic B Vector Plot
t = 0.008
t = 0.011 Simulation Results
Secondary winding current
Output voltage from rectifier
Output voltage from rectifier
Notch caused by
switching on-off
Current
Induced voltage hysteresis loss
eddy loss
excess loss
!
Applicable to
Electric Steel
and
Power Ferrite
!
Consider hysteresis minor loop
!
Based on available manufacturer coefficients
Core temperature distribution
(steady state analysis)
Average core loss Device Geometry and Source
Source current
Coil
Aluminum
cylinder Force distribution on Aluminum
Cylinder (N/m
3
) Current distribution in the
Aluminum Cylinder Vector plot of Induced Current in
Aluminum Cylinder Position sensor analysis
Permanent magnet
Coil (2 KHz)
Permeable core
Magnetic flux density plot
(0.15 mm thick)
Eddy currents in the core Ferrite Core Inductor
Parametric definition of the coil:
x= (a * sin (t * c) + b) cos t
y = (a * sin (t * c) + b) sin t
z = a * cos (t * c)
c = number of turns
a = radius of the turn
b = median radius of the torus Ferrite Core Inductor
I (t) = 15 sin (2 pi 500 t) Ferrite Core Inductor Ferrite Core Transformer
I(t), 500 Hz
50 Ohms Ferrite Core Transformer
Current induced
In conductive core
Currents in coils
Mag. Flux density