Tutorial Induction Machine Calculations

Induction MachineCalculations in Flux2D

Preflux2D 9.2

Copyright 2006 Magsoft Corporation

All rights reserved. No part of this work may be reproduced or used in any form or by anymeansgraphic, electronic, or mechanical, including photocopying, recording, taping, Webdistribution or information storage and retrieval systemswithout the written permission of thepublisher.

www.magsoft-flux.com

Cover illustration: Model showing shade plot of the induction motor

1 Physical properties 1

Start Preflux 9.2 1

Open the induction machine geometry 2

Using the menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Define Steady State AC Model 5

Change to the Physics context 7

Physics context toolbars 9

Import materials from the materials database 10

Select an Equivalent B(H) Curve For Iron 12

Import the problem circuit 14

Define the circuit component properties 16

Define the circuit resistors 16

Define the circuit inductors 17

Define the power supply 18

Define the coils 21

Define the squirrel cage 22

Creating Mechanical Sets 24

Create the MOVING_ROTOR Mechanical Set 25

Create the FIXED_STATOR Mechanical Set 27

Create the ROTATING_AIRGAP Mechanical Set 28

Save your problem 30

i

ContentsUsing the icon in the toolbar 30

Using the menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

2 Add and assign regions for the faces 31

About surface regions 31

Add the 7 rotor bar regions 33

Open the Add Region Face dialog 33

Using the icon in the toolbar . . . . . . . . . . . . . . . . . . . . . . . . . 33

Using the menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Add the data for the first rotor bar region (RB1) 34

Add the other rotor bar regions 36

Add the rotor region 38

Add the AIRGAP region 41

Add regions for the stator slots 43

Add the STATOR surface region 47

About assigning geometric faces to the region faces 51

Assign the seven rotor bars 53

Open the Assign Region to Faces dialog 53

Using the icon in the toolbar . . . . . . . . . . . . . . . . . . . . . . . . . 53

Using the menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Assign the first rotor bar to RB1 55

Assign the other rotor bars 56

Assign the stator slots 60

Assign the rotor 63

Assign the stator 63

Assign the airgap 64

Contentsii

Check the physical model 66

3 Solve in Direct or Batch mode 69

Check the version: Flux2D Standard 70

Start the solver 71

Solving in direct mode 72

Solving in batch mode 77

Prepare the batch file 77

Start the batch computation 82

4 Analyze results with PostPro_2D 85

Start PostPro_2D 86

Display the full geometry 88

Display isovalues plots 89

Display the isovalues plot at phase = 0 91

Display the plot at phase = 30 92

Display the plot at phase = 60 93

Display color shade plots on the stator and rotor regions 95

Create a group of the stator and rotor regions 95

Display a flux density plot 97

Display a saturation map (permeability) 99

Create a group of the rotor bars 100

Display a power density plot in the rotor bars 102

Display the current density in the first rotor bar 104

Contents iii

Computations of torque and power values 107

Compute the torque in the airgap 108

Compute the current and power supply values in each phase 110

Compute the electric quantities for other components 114

Save the results of your computations 115

Analyze the flux density in the airgap 116

Create a path through the center of the airgap 116

Create curves using the airgap path 121

Flux density: Magnitude . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Flux density: Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Flux density: Normal component . . . . . . . . . . . . . . . . . . . . . . 124

Flux density: Tangential component . . . . . . . . . . . . . . . . . . . . . 125

Superimpose the Magnitude and Direction curves . . . . . . . . . . . . . 127

Superimpose the Normal and Tangential curves . . . . . . . . . . . . . . 131

Create a spectrum analysis of the normal component of the flux density 132

Plot the flux density at phase = 30 136

Current distribution in the rotor bars 138

Create a path through the first rotor bar 139

Create a curve using the rotor bar path 142

Save and close PostPro_2D 145

5 Parameterized solution at different speeds 147

Use SOLVER_2D to parameterize the speed and slip 147

Open SOLVER_2D 148

Save the problem under a new name 150

Open the parameterization tools 151

Contentsiv

Choose the computation method, mono- or multi-parametric 152

Select the parameter to vary 152

Set the parameter variation for the slip: List of values 154

Close the parametrisation tools 156

Solve the parametric computation 156

PostPro_2D: Analyze the results 158

Open the postprocessor 158

Create curves and extract power values 161

Torque vs. slip (different speeds) . . . . . . . . . . . . . . . . . . . . . . 161

Create curves of the active power in the voltage sources . . . . . . . . . . 163

Create curves of the current in the voltage sources . . . . . . . . . . . . . 166

Display the curves and write the values into the review file 169

Display the torque-slip curve . . . . . . . . . . . . . . . . . . . . . . . . . 169

Display the input power (active power) curves . . . . . . . . . . . . . . . 172

Display the current curves . . . . . . . . . . . . . . . . . . . . . . . . . . 176

Save the Review file 180


6 Transient analysis at 1459 rpm 183

Physical properties 183

Start Preflux 9.2 183

Open the magnetodynamic problem 185

Save your project with a new name 187

Redefine the model to be a Transient Magnetic 189

Import and define the drive circuit for Transient Magnetics 190

Define the power supply (voltage sources) 191

Contents v

Define the rotor bar regions for Transient Magnetics 194

Assign iron (nonlinear steel) to the rotor and stator 196

Define the stator slot regions 199

Assign vacuum to the Airgap region 202

Specify the rotor speed in the Mechanical Set 204

Check the Physical Model and Close Preflux 209

Transient startup 210

Solving with transient startup 213

Choosing the time step 213

Solving strategy for harmonic analysis: batch mode 213

Start the batch computation 217

Analyze results from the constant speed problem 220

Start PostPro_2D 220

Choose the time step to analyze 222


Display isovalues plots 225

Display the isovalues plot at t = .05 s 226

Display the isovalues plot at t = .055 s 226

Analyze the flux density through the airgap 227

Create a path through the airgap . . . . . . . . . . . . . . . . . . . . . . . 227

Create curves using the airgap path . . . . . . . . . . . . . . . . . . . . . 232

Spectrum analysis of the normal component curve . . . . . . . . . . . . . 235

Create curves of torque and electrical quantities 239

Axis torque curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

Voltage in VAC curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

Current in VAC curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

Contentsvi

Current in the PA coil curve . . . . . . . . . . . . . . . . . . . . . . . . . 242

Voltage in the PA coil curve . . . . . . . . . . . . . . . . . . . . . . . . . 243

Voltage in the first rotor bar curve . . . . . . . . . . . . . . . . . . . . . . 243

Current in the first rotor bar curve . . . . . . . . . . . . . . . . . . . . . 244

Spectrum analyses 245

Spectrum analysis of VAC current . . . . . . . . . . . . . . . . . . . . . . 247

Spectrum analysis of PA current . . . . . . . . . . . . . . . . . . . . . . . 247

Spectrum analysis of Bar1 current . . . . . . . . . . . . . . . . . . . . . . 248

Display the curves and extract the values 249

Display the axis torque curve . . . . . . . . . . . . . . . . . . . . . . . . . 249

Display the spectrum analysis of the axis torque . . . . . . . . . . . . . . 252

Superimpose the VAC voltage and current curves . . . . . . . . . . . . . 256

Display the spectrum of the VAC current curve . . . . . . . . . . . . . . 257

Superimpose the PA voltage and current curves . . . . . . . . . . . . . . 260

Display the spectrum of the PA current curve . . . . . . . . . . . . . . . 261

Superimpose the voltage and current curves for the first rotor bar. . . . . 263

Display the spectrum analysis of the current in the first rotor bar . . . . . 264

Save Review file values 265


7 Transient analysis: electromechanical coupling269

Physical properties 269

Start Preflux 9.2 269

Open the constant speed problem 270

Save your project with a new name 272

Redefine the Rotor mechanical set 274

Close the Preflux Application 277

Contents vii

Solve the no load startup problem 278

Configure the Solver Options 280

Start the Solver 281

Analyze results from no load startup 285

Start PostPro_2D 285


Display the isovalues plot at time step 1 288

Display the isovlaues plot at time step 20 289

Analyze the flux density through the airgap 291

Create a path through the airgap . . . . . . . . . . . . . . . . 291

Create normal and tangential flux density curves using the airgap path . . . . . . 294

Display the normal component curves . . . . . . . . . . . . . . . . . . . . . . . . 297

Create a spectrum analysis of the normal component curve at t = 0.28 s . . . . . 299

Create curves of mechanical and electrical quantities 302

Create curves of the axis torque, position and angular velocity . . . . . . . . . . . 302

Display the mechanical quantity curves using the data tree . . . . . . . . . . . . . 306

Create a spectrum analysis of the second axis torque curve . . . . . . . . . . . . . 311

Create curves of voltage and current in circuit components . . . . . . . . . . . . 315

Create spectrum analyses of the VAC and PA current curves 320

Display the voltage and current curves 322

Display the spectrum analyses using the curves list in the data tree . . . . . . . . 325

Save Review file values 327


Close Flux2D 329

Contentsviii

Physical properties

To enter the physical properties, use the Preflux 9.2 application, the same application used tocreate the geometry and mesh (in previous versions of Flux, a separate application, the PhysicalProperties module, Prophy, was used).

Start Preflux 9.2

In the Flux Supervisor, in the Construction folder, double click Geometry & Physics:

Program Input

Double click Geometry & Physics

1

Chapter 1

Starting Preflux 9.2 to enter the physical properties

The Preflux 9.2 application opens:

Open the induction machine geometry

You can open an existing project either with the toolbar icon or the menu.

Using the icon in the toolbar

To open a new Flux project, click the icon on the toolbar

Program Input

click

Start Preflux 9.2 Physical properties

Page Chapter 12

Preflux 9.2 screen

Using the menu

If you prefer, choose Project, Open project from the menu:

Program Input

Project

Open project...

The Open project dialog appears:

Physical properties Start Preflux 9.2

Chapter 1 Page 3

Opening the induction machine geometry

Enter or verify the following:

Program Input

Look in: Flux_Work [your workingdirectory)]

FileName: Ind_Motor [your name]

Open

The induction motor model is displayed:

Start Preflux 9.2 Physical properties

Page Chapter 14

Induction machine opened in Preflux

Define Steady State AC Model

Define this as a steady state AC magnetic problem using the Application menu:

Program Input

Application

Define

Magnetic

Steady State AC

Magnetic 2D

The Define Steady State AC Magnetic 2D application dialog opens:


Program Input

Frequency in Hertz 50

Physical properties Define Steady State AC Model

Chapter 1 Page 5

Defining the physical application for the induction machine

Program Input

2D domain type 2D plane

Length Unit MILLIMETER

Depth of the domain 145

Symmetry & Periodicity =>

Coefficient for coils flux

computation

Automatic coefficient

OK

Your screen should look like the following. Notice that there is a new context symbol,representing the Physical model context.

Define Steady State AC Model Physical properties

Page Chapter 16

Induction machine model after defining physical application

Change to the Physics context

The Physics commands are available only in the Physics context. The following figure shows thePhysics context selected:

At the top of the data Tree, click the button to change to the Physics context.

Program Input

click

Physical properties Change to the Physics context

Chapter 1 Page 7

The Physics context is shown in the following figure:

Change to the Physics context Physical properties

Page Chapter 18

Induction machine model after moving to the Physics context

Physics context toolbars

The Physics context includes some of the same icons and commands as the Geometry and Meshcontexts. Most of the Display and Select icons are the same.

The following figures show the Physics toolbar icons:

The following figures identify the Physics toolbar icons:

Physical properties Change to the Physics context

Chapter 1 Page 9

Physics toolbar icons: Add, Check

Physics toolbar icons: Display, Select

Import materials from the materials database

Before we can assign materials we created to the different regions of our model, we must importthem. Use the menu, Physics, Material, Import material.

Program Input

Physics

Material

Import material

The import material dialog appears. Click on the icon next to the material database name todisplay the list of materials in the database.

Now scroll to find the two materials you want to import; ALUMINUM and IRON. Select bothwith the mouse using the Control key.

Import materials from the materials database Physical properties

Page Chapter 110

List of materials in the database

Proceed as follows:

Program Input

Click ALUMINUM

Click IRON + Ctrl

Import

After the import is complete, close the Import materials window.

Program Input

Close

If you expand the Materials in the data tree, you will see the two materials now included in theproject.

Physical properties Import materials from the materials database

Chapter 1 Page 11

Materials imported into project

Select an Equivalent B(H) Curve For Iron

In a Steady state AC Magnetic application, the unknown state variables and the derived physicalquantities - magnetic field strength and magnetic flux density - are supposed to be harmonic(sinusoidal) time dependent. In reality, if the field computation domain includes nonlinearmagnetic materials, the magnetic field H and the magnetic induction H cannot have sinusoidaltime dependence simultaneously.

To account for this, you can select an "equivalent" B(H) curve for the nonlinear material. If themodel has a current supply, the sinusoidal magnetic field strength model is used. If the modelhas a voltage supply, like this one, the sinusoidal magnetic flux density model is used. Moreinformation on this can be found in Volume 2 of the User's Guide.

Double-click on IRON in the data tree to edit the material:

Program Input

Double-click IRON

Import materials from the materials database Physical properties

Page Chapter 112

The Edit Material [IRON] opens:


Program Input

Name of the material IRON

Comment nonlinear steel

Magnetic property Isotropic spline saturation

Type of equivalent B(H) curve Sine wave flux density

OK

Physical properties Import materials from the materials database

Chapter 1 Page 13

Defining the physical application for the induction machine

Import the problem circuit

Before we can assign the components in the circuit we created earlier to the different regions ofour model, we must import the circuit.

To import the circuit we created, click the icon on the toolbar.

Program Input

click

If you prefer, choose Physics, Circuit, Import circuit from a CCS file from the menu:

Program Input

Physics

Circuit

Import circuit from a CCS file

The Import circuit dialog appears. Click on the browse file selector in the dialog box.

Program Input

click

Import the problem circuit Physical properties

Page Chapter 114

The Open circuit dialog appears.


Program Input

Look In: Flux_Work [your workingdirectory]

File Name: Ind_Motor_Circuit.ccs [yourname]

Open

The circuit file name is transferred to the Import Circuit dialog box.

Proceed as follows:

Program Input

click OK

Physical properties Import the problem circuit

Chapter 1 Page 15

Selected circuit ready for import

The circuit is displayed on the screen. If you expand the data Tree under the Electric Circuitnode, you will see the components from the imported circuit.

Define the circuit component properties

Now that the circuit is imported into your problem, each individual component has propertiessuch as resistance that need to be defined. By performing these assignments inside a particularmodel, the same circuit can be used for various models with unique properties.

Define the circuit resistors

With the "Edit Array" command in Flux, you can define the resistance of all the circuit resistorsas one time. To edit the resistors in the data tree, first expand the data tree to display theresistors (under the Electric Circuit node, then under RLC Components). Select R1, R2 and R3using the mouse and Control key. Next, use the right mouse button to display the contextmenu.

Define the circuit component properties Physical properties

Page Chapter 116

Imported circuit displayed as a new "tab" in the graphics area

Proceed as follows:

Program Input

Click R1

Click R2 + Ctrl

Click R3 + Ctrl

Right-click, Edit array

The Edit Resistor dialog appears. In the Modify All column, enter the resistance.

Proceed as follows:

Program Input

Modify all - Resistance (Ohm) 0.5575*4

OK

Define the circuit inductors

Similarly, use the Edit Array command to edit the inductors in the data tree (under the ElectricCircuit node, then under RLC Components). Select L1, L2 and L3 using the mouse and Controlkey. Next, use the right mouse button to display the context menu and select "Edit Array."

Physical properties Define the circuit component properties

Chapter 1 Page 17

Setting the resistance for the circuit resistors

The Edit Inductor dialog appears. In the Modify All column, enter the inductance.

Proceed as follows:

Program Input

Modify all - Inductance(Henry) 0.0021*4

OK

Define the power supply

Because we defined the physical model with the option "Automatic coefficient" (see page 6), wedefine the voltage source with the value for the entire motor. Flux will internally scale the circuitto whatever portion of the full motor we are modeling. The Voltage Sources are definedindividually because of the phase difference. To edit the first voltage source, you can select itfrom the data tree (under the Electric Circuit node, then under Voltage/Current sources). SelectVAC, then use the right mouse button to display the context menu and select "Edit".

Proceed as follows:

Program Input

Click VAC

Right-click, Edit


Page Chapter 118

Setting the inductance for the circuit inductors

The Edit Voltage Source dialog appears:


Program Input

Voltage source name VAC

Comment Voltage source phase A-C

Value 380

Phase in degree 0

OK


Chapter 1 Page 19

Defining the VAC voltage source

Now define the other voltage source. With the circuit diagram displayed, you can select and editcomponents graphically. Double-click the VBA component, or right-click on it to display thecontext menu and select "Edit".

Proceed as follows:

Program Input

Click VBA component

Right-click, Edit


Page Chapter 120

Graphically selecting the VBA voltage source to edit

The Edit Voltage Source dialog appears:


Program Input

Voltage source name VBA

Comment Voltage source phase B-A

Value 380

Phase in degree -120

OK

Define the coils

Use the Edit Array command to edit the coils in the data tree (under the Electric Circuit node,then under Fe Coupling Components, then under Stranded Coil Conduction). Select BMC,BPA and BPB using the mouse and Control key. Next, use the right mouse button to displaythe context menu and select "Edit Array"


Chapter 1 Page 21

Defining the VBA voltage source

The Edit Stranded Coil dialog appears. In the Modify All column, enter the resistance. Thenumber of turns in each coil will be defined later.

Proceed as follows:

Program Input

Modify all - Resistance formula 0.46557*4

OK

Define the squirrel cage

To edit the squirrel cage, select it from the data tree (under the Electric Circuit node, then underRotating machine components). Select Q1, then use the right mouse button to display thecontext menu and select "Edit".

Proceed as follows:

Program Input

Click Q1

Right-click, Edit


Page Chapter 122

Setting the resistance for the coils

The Edit Squirrel Cage dialog appears:


Program Input

Squirrel cage name Q1

Number of bars 7

Resistance of the portion ofend rings between two adjacentbars (Ohm)

2.5e-6

Inductance of the portion ofend rings between two adjacentbars (Henry)

4e-9

OK

This concludes the definition of the circuit. Click the GeometryFlux2DView tab at the bottomof the screen to return to the geometric view of the model.

Program Input

Click GeometryFlux2DView

Chapter 1 Page 23


Defining the squirrel cage

Creating Mechanical Sets

New with Flux 9.2 is the existence of Mechanical Sets. Mechanical Sets are used whenever youwant motion in the model (either rotating or translating). Whenever there is motion in themodel, you must define 3 mechanical sets;

Fixed - This defines the parts of the model that do not move

Moving - This defines the parts of the model that move (either rotating or translating)

Compressible - This defines the region between the moving and non-moving parts (and thedisplacement regions, in the case of translating motion)

We will first create these mechanical sets. Later, parts of the model will be assigned to theseMechanical Sets. Select Physics, Mechanical Set and New from the menu.

Program Input

Physics

Mechanical set

New

Creating Mechanical Sets Physical properties

Page Chapter 124

Create the MOVING_ROTOR Mechanical Set

The New Mechanical set dialog appears. Enter the information to create theMOVING_ROTOR mechanical set.

Proceed as follows:

Program Input

Mechanical set name moving_rotor

Comment The moving parts of the model

Type of mechanical set Rotation around one axis

Rotation Axis Rotation around one axis

parallel to Oz

Coordinate system ROTMAIN

Pivot point

First coordinate 0

Physical properties Creating Mechanical Sets

Chapter 1 Page 25

Defining the Axis information for the MOVING_ROTOR Mechanical

Set

Program Input

Second coordinate 0

Click on "Kinematics" tab

The Kinematics tab opens. Enter the information to define the kinematics, then click OK.

Proceed as follows:

Program Input

Type of kinematics Multi static

Optional value for slip 0.0273

OK


Page Chapter 126

Defining the Kinematics information for the MOVING_ROTOR

Mechanical Set

Create the FIXED_STATOR Mechanical Set

The New Mechanical set dialog closes briefly and then reappears. Enter the information to create the FIXED_STATOR mechanical set.

Proceed as follows:

Program Input

Mechanical set name fixed_stator

Comment the non-moving parts of the model

Type of mechanical set Fixed

OK


Chapter 1 Page 27

Defining the information for the FIXED_STATOR Mechanical Set

Create the ROTATING_AIRGAP Mechanical Set

The New Mechanical set dialog closes briefly and then reappears. Enter the information to create the ROTATING_AIRGAP mechanical set.

Proceed as follows:

Program Input

Mechanical set name rotating_airgap

Comment the rotating airgap

Type of mechanical set Compressible

Used method to take the motioninto account

Remeshing of the air partsurrounding the moving body

OK


Page Chapter 128

Defining the information for the ROTATING_AIRGAP Mechanical

Set

The New Mechanical set dialog closes briefly and then reappears. Close the dialog by hitting theCancel button.

Proceed as follows:

Program Input

Cancel


Chapter 1 Page 29

Close the Mechanical set dialog

Save your problem


Save your problem now (if you wish) by clicking the button in the toolbar.

Program Input

click

Using the menu

If you prefer, choose Project, Save from the menu.

Program Input

Project

Save

Save your problem Physical properties

Page Chapter 130

Add and assign regions for the faces

In this chapter you will create regions to represent different parts of the motor. To makecalculations later, you will assign materials or source properties to these regions (such asaluminum for the rotor bars or plus A 1" for the first three stator slots).

About surface regions

Surface regions are created by entering names, comments (reflecting the material or sourceproperties, in this case), materials, circuit components, mechancal sets and colors for each of the19 faces of the geometry. For instance, the first rotor bar at the bottom of the figure will benamed RB1, identified as composed of aluminum, in the MOVING_ROTOR mechanical set,assigned to the first bar of the squirrel cage, and assigned the color turquoise.

Creating region faces is similar to creating parameters or coordinate systems. You will not seeany changes in the model display on your graphics screen while you enter the information tocreate the region faces. However, you will see confirmation messages in the Console window.

31

Chapter 2The following figure shows which features of the geometry will be assigned to each named regionface.

About surface regions Add and assign regions for the faces

Page Chapter 232

Labels for surface regions

Add the 7 rotor bar regions

Begin by adding a region for each of the rotor bars.

Open the Add Region Face dialog


To add the surface regions, open the New Region Face dialog with the button

Program Input

click

Using the menu

If you prefer, choose Physics, Face Region, New from the menu:

Program Input

Physics

Face Region

New

Add and assign regions for the faces Add the 7 rotor bar regions

Chapter 2 Page 33

The New Region Face dialog will open:

Add the data for the first rotor bar region (RB1)


Program Input

Name of the region RB1

Comment rotor bar 1, aluminum

Type of region Solid conductor region

Material of the region ALUMINUM

Type of the conductor Circuit

Associated solid conductor BAR_1_Q1

Positive orientation for thecurrent

Click Appearance

Add the 7 rotor bar regions Add and assign regions for the faces

Page Chapter 234

Defining material for surface region RB1, for the first rotor bar

The data for the Appearance is displayed.


Program Input

Color Turquoise

Visibility Visible

Click Mechanical Set


Chapter 2 Page 35

Defining color for surface region RB1

The data for the Mechanical set is displayed.


Program Input

Mechanical Set MOVING_ROTOR

OK

The New Face region dialog closes briefly and then reappears.

Add the other rotor bar regions

Add the data for the other rotor bar regions as follows. Since the color and mechanical set is thesame for these bars as the first bar, there is no need to go to the Appearance tab or theMechancial Set tab. You just need to change the Name, Comment and Associated SolidConductor for each new region:


Page Chapter 236

Defining the Mechanical Set for surface region RB1

Program Input

RB2

rotor bar 2, aluminum

Solid conductor region

ALUMINUM

Circuit

BAR_2_Q1

Positive orientationfor the current

OK

Name of the region:

Comment:

Associated Solid Conductor

RB3


BAR_3_Q1

OK

Name of the region:

Comment:


RB4


BAR_4_Q1

OK

Name of the region:

Comment:


RB5


BAR_5_Q1

OK

Name of the region:

Comment:


RB6


BAR_6_Q1

OK

Name of the region:

Comment:


RB7


BAR_7_Q1

OK


Chapter 2 Page 37

Add the rotor region

The new face region dialog should still be open.


Program Input

Name of the region ROTOR

Comment iron (nonlinear steel)

Type of region Magnetic non conducting region

Material of the region IRON

Click Appearance


Page Chapter 238

Defining material for ROTOR, the face region of the machine rotor

The data for the Appearance is displayed. The rotor should be a different color. The followingshows Cyan being selected:


Program Input

Color Cyan

Visibility Visible



Chapter 2 Page 39

Defining color for surface region ROTOR

The data for the Mechanical Set is displayed:


Program Input

Mechanical Set MOVING_ROTOR

OK


Page Chapter 240

Defining the Mechanical Set for surface region ROTOR

Add the AIRGAP region

Now add the AIRGAP region.


Program Input

Name of the region AIRGAP

Comment moving airgap

Type of region Air or vacuum region

Click Appearance


Chapter 2 Page 41

Defining material for AIRGAP, the face region gap between rotor and stator

The data for the Appearance is displayed. The air gap should be a different color. The followingshows Yellow being selected:


Program Input

Color Yellow

Visibility Visible



Page Chapter 242

Defining the color of the AIRGAP region

The data for the Mechanical Set appears. Select the Mechanical Set defined earlier as a"Compressible" mechanical set:


Program Input

Mechanical Set ROTATING_AIRGAP

OK

Add regions for the stator slots

The three regions for the stator slots represent the three coils of the external circuit (one perphase). In our model, each region will be assigned 3 stator slots.


Chapter 2 Page 43

Defining the Mechanical Set of the AIRGAP region

The New Region Face dialog should still be open.


Program Input

Name of the region SSA

Comment plus a, 3 slots

Type of region Coil conductor region

Material of the region

Positive orientation for thecurrent

Number of turns of theconductor

132

Coil conductor region component BPA

Symetries and periodicities -conductors in series or inparallel

All the symmetrical andperiodical conductors are inseries

Click Appearance


Page Chapter 244

Defining the material for the SSA region

The data for the Appearance is displayed. The slot should be a different color. The followingshows Red being selected:


Program Input

Color Red

Visibility Visible



Chapter 2 Page 45

Defining the color of the SSA region

The data for the Mechanical Set appears. Since the slots are in the stator, select the MechanicalSet defined as stationary, FIXED_STATOR.


Program Input

Mechanical Set FIXED_STATOR

OK

Add the regions for the other two stator slots. The only difference in the definition of theseslots with the first slot is the Name, Comment, Coil Component and Color. The following tabledescribes these changes for the remaining stator slots:

Program Input

Name of the region

Comment

Coil conductor region component

Color

SSB

plus b, 3 slots

BPB

Click Appearance

Magenta

OK


Page Chapter 246

Defining the Mechanical Set of the SSA region

Program Input

Name of the region

Comment

Coil conductor region component

Color

SSC

minus c, 3 slots

BMC

Click Appearance

Yellow

OK

Add the STATOR surface region

Finally, add the STATOR surface region, as shown below:


Chapter 2 Page 47

Defining the material for the STATOR surface region


Program Input

Name of the region STATOR

Comment iron (nonlinear steel)

Type of region Magnetic non conducting region

Material of the region IRON

Click Appearance

The data for the Appearance is displayed.


Program Input

Color Cyan

Visibility Visible



Page Chapter 248

Defining the color for the STATOR surface region

The data for the Mechanical Set appears. Obviously, we will be selecting the Mechanical Setnamed FIXED_STATOR


Program Input

Mechanical Set FIXED_STATOR

OK


Chapter 2 Page 49

Defining the Mechanical Set for the STATOR surface region

When the New Region Face dialog reopens, close it.

Program Input

Name of the region (STATOR_1) Cancel


Page Chapter 250

Closing the New Region Face dialog

About assigning geometric faces to the region faces

Next you will assign the region faces to the appropriate geometric faces.

When you select a geometric face to assign it to a surface region, the face will change to a darkercolor. In the dialog, the program will display the automatically assigned face number (for the firstrotor bar, the Face number is 2, in our example).

The following figure shows the first rotor bar being selected for assignment to region RB1:

After you choose the region face name from the menu list, the face you have assigned changescolor again (to white or invisible).

Add and assign regions for the faces About assigning geometric faces to the region faces

Chapter 2 Page 51

Selecting the first rotor bar to assign to region face RB1

For example, the following figure shows the screen after region face RB1 has been assigned.

About assigning geometric faces to the region faces Add and assign regions for the faces

Page Chapter 252

Screen after assigning the first rotor bar to RB1 region face

Assign the seven rotor bars

Now begin by assigning the seven rotor bars to their respective surface regions (RB1, RB2, etc.).The following figure shows which bars are assigned to the rotor bar regions.

Open the Assign Region to Faces dialog


Open the Assign Region to Faces dialog with the button in the toolbar.

Program Input

click

Add and assign regions for the faces Assign the seven rotor bars

Chapter 2 Page 53

Labels for rotor bar regions

Using the menu

If you prefer, choose Geometry, Assign regions to geometric entities, Assign Region to Faces(completion mode) from the menu.

Program Input

Geometry

Assign regions to

geometric entities

Assign Region to Faces (completion mode)

The Assign Region to Faces dialog will open:

Assign the seven rotor bars Add and assign regions for the faces

Page Chapter 254

Assigning RB1 region face to rotor bar 1 (Face 2)

Assign the first rotor bar to RB1

Proceed as follows:

Program Input

List of Faces

Face

2 [first rotor bar]

Region Face for Faces RB1

OK

After you have assigned the first rotor bar, your screen should resemble the following figure.

The Assign Region to Faces dialog should still be open.


Chapter 2 Page 55

First rotor bar assigned to region face RB1

Assign the other rotor bars

Because the face numbers assigned by FLUX may vary, the figures in the following sequenceshow both the model and the dialog, so that you can see which rotor bar face is being selected forwhich region. (Your screen may not look exactly like these figures; they are composites createdfor your reference.)

Your input into the Assign Region to Face dialog is in the right column, as before.

To assign the other rotor bars, proceed as follows.

Program Input

11 [second rotor bar]

RB2

OK

12 [third rotor bar]

RB3

OK


Page Chapter 256

Program Input

13 [fourth rotor bar]

RB4

OK

14 [fifth rotor bar]

RB5

OK


Chapter 2 Page 57

Program Input

15 [sixth rotor bar]

RB6

OK

16 [seventh rotor bar]

RB7

OK


Page Chapter 258

With all seven bars assigned, your screen should resemble the following figure:


Chapter 2 Page 59

Rotor bars assigned to regions RB1 - RB7

Assign the stator slots

Now assign the stator slots to the three coil regions. The following figure shows which slots areassigned to each of the three slot regions (SSA, SSB, SSC).

Because the face numbers assigned by FLUX may vary, the figures in the following sequenceshow the full screen, so that you can see which slots are being selected.

Your input into the Assign Region to Faces dialog is in the right column, as before.

To select more than one slot at the same time, click the first slot, hold down theCtrl key, and then click the second and third slots.


Page Chapter 260

Labels for stator slot regions

Assign the stator slots as follows.

Program Input

1 [first slot] + Ctrl

3 [second slot]

4 [third slot]

SSA

OK

8 [seventh slot]+ Ctrl

9 [eighth slot]

10 [ninth slot]

SSB

OK


Chapter 2 Page 61

Program Input

5 [fourth slot] + Ctrl

6 [fifth slot]

7 [sixth slot]

SSC

OK

With the nine slots assigned your screen should resemble the following figure:


Page Chapter 262

Stator slots assigned to SSA, SSC, SSB region faces

Assign the rotor

Now assign the ROTOR region face as follows:

Program Input

19 [rotor face]

ROTOR

OK

Assign the stator

Assign the stator face as follows:

Program Input

17 [stator face]

STATOR

OK


Chapter 2 Page 63

Assign the airgap

The only face remaining to assign is the airgap. When assigning the last region using "completionmode", you can use the "Select All" command to select all remaining faces. The following figureshows the airgap being selected using the "Select All" command:

Proceed as follows:

Program Input

Click

Select all


Page Chapter 264

Selecting the airgap to assign the AIRGAP surface region

Program Input

18 [airgap face]

AIRGAP

OK


Chapter 2 Page 65

The surface regions will be displayed in their assigned colors, as shown in the following figure:

Check the physical model

Now that all physical attributes have been assigned to our model, we should have Flux check itbefore proceeding to solving.

Select the icon from the toolbar to start the Physical Check.

Program Input

Click

Check the physical model Add and assign regions for the faces

Page Chapter 266

Surface regions assigned

If you prefer, you can select Physics, Check physics from the menu.

Program Input

Physics

Check physics

The console indicates that the physical check is completed.

Add and assign regions for the faces Check the physical model

Chapter 2 Page 67

The model is ready for solving. Close the Preflux application.

Select Project, Exit from the menu.

Program Input

Project

Exit

When prompted, select to save your problem.

Proceed as follows:

Program Input

Save current project before Yes

The Flux Supervisor is displayed.

Check the physical model Add and assign regions for the faces

Page Chapter 268

Solve in Direct or Batch mode

Now use SOLVER_2D to solve the finite element problem you have defined. You can solvedirectly or in batch mode, which allows you to run Flux2D in the background. We describe bothoptions below.

The solver forms the equations matrix and solves it iteratively. The size of the matrix and thesolution time depend on the number of nodes in the finite element mesh, the number of circuitcomponents and the electromechanical equation.

Because this problem uses nonlinear materials and the computation is carried out iteratively, youshould specify the maximum number of iterations and the precision. Flux2D will continueiterating until it reaches either this precision or the maximum number of iterationswhichevercomes first.

If the solution does not converge within the number of iterations you specified, you can increasethe maximum number of iterations afterwards. For nonlinear problems, you can use an improved algorithm for speeding up the Newton-Raphson calculation. This progressive algorithm modifiesthe parameters and results in a significant savings in computing time for problems requiring more than 15 Newton-Raphson iterations.

69

Chapter 3Check the version: Flux2D Standard

Before you start solving the steady state AC magnetic problem, in the Flux2D Supervisor, makesure that Flux2D: Standard is shown in the Program manager at the top of the Supervisorwindow.

If you do not see "Flux2D: Standard", choose Versions, Standard from the menu.

Program Input

Versions

Standard

Check the version: Flux2D Standard Solve in Direct or Batch mode

Page Chapter 370

Start the solver

To start solving, in the Flux2D Supervisor, in the Solving process folder, double click Direct:

Program Input

Double click Direct

Solve in Direct or Batch mode Start the solver

Chapter 3 Page 71

Starting the solver

In the Open dialog, select the problem to be solved and click Open:

Solving in direct mode

In the Solver window, click the Options tab to bring it to the front:

Solving in direct mode Solve in Direct or Batch mode

Page Chapter 372

Checking the solving options

Choosing the problem to solve

Enter or verify the options as follows:

Program Input

Magnetic, Electric iterations

Number of iterations 50

Requested precision 1.e-004

Thermal iterations



Magnetic updatings to coupledproblem

Minimal number of updatings 1

Maximal number of updatings 5


Be sure that the Newton-Raphson algorithm is Disabled, as shown in the following figure:

Program Input

Progressive Newton Raphsonalgorithm

Disabled

Accuracy definition Automatic accuracy

Solver type SuperLu without pivoting

Priority associated to thecomputation

Priority normal

Apply

Click Apply to verify the options.

Solve in Direct or Batch mode Solving in direct mode

Chapter 3 Page 73

Then click the Solve button to begin the computation.

Program Input

click

The following dialog will open:

Do not change the initial position of the rotor. Click OK to close this dialog

Program Input

Initial position of the rotor

0 degrees

OK


Page Chapter 374

Verifying the initial position of the rotor (0 degrees)

Watch as the solution proceeds. It may take some time.

Solve in Direct or Batch mode Solving in direct mode

Chapter 3 Page 75

Solving (direct mode)

When the computation is finished, the Status: computation finished message will be displayedin the dialog window:

Choose File, Exit to close the solver:

Solving in direct mode may require a relatively long time. You may wish to solve in batch mode:see below.


Page Chapter 376

Closing the solver

Computation finished

Solving in batch mode

Solving in batch mode can reduce the computation time.

To solve in batch mode, you must prepare a batch file of the information required to solve theproblem: the maximum number of iterations, the precision required, the solution method oralgorithm, how the problem is to be solved, and so on.

Prepare the batch file

In the Flux2D Supervisor, in the Solving process folder, double click Direct to openSOLVER_2D.

Solve in Direct or Batch mode Solving in batch mode

Chapter 3 Page 77

Starting the solver

In the Open dialog, choose the problem to be solved and click OK:

In the Solver window, click the Options tab to bring it to the front:

Solving in batch mode Solve in Direct or Batch mode

Page Chapter 378

Checking the solving options

Choosing the problem to solve (to prepare a batch file)

Enter or verify the options as follows:

Program Input

Magnetic, Electric iterations



You do not need to change any of the other options.


Chapter 3 Page 79

To prepare the batch file with the number of iterations and the requested precision, click the

button.

Program Input

click

The following dialog will open:

Do not change the initial position of the rotor. Click OK to close this dialog

Program Input

Initial position of the rotor

0 degrees

OK


Page Chapter 380

Verifying the initial position of the rotor (0 degrees)

You should see the Preparation of batch file completed message in the dialog:

Close the solver with File, Exit:

The batch file has been created. Flux2D has created a file called IND_MOTOR.DIF that will beused to start the batch job.


Chapter 3 Page 81

Closing the solver

Batch file completed

Start the batch computation

In the Flux2D Supervisor, in the Solving process folder, double click Batch:

Program Input

Double click Batch


Page Chapter 382

Starting the solver for a batch computation

In the Batch window, the names of problems with batch files prepared show a "Yes" in the Readycolumn, as shown in the following figure.

Select the problem you wish to solve, e.g., IND_MOTOR, and click the Start button to beginthe computation:


Chapter 3 Page 83

Starting the batch computation

The Solver window will open:

When the problem has finished solving, the Supervisor with the Batch window opens again.Choose Quit to close the Solver.

The Flux2D Supervisor should remain open. You will analyze the results next.


Page Chapter 384

Closing the solver after batch computation

Batch computation in progress

Analyze results with PostPro_2D

Use PostPro_2D to analyze your results. With PostPro_2D module you can display a variety ofplots of the results, compute various local and global values, create animations and graphics forpresentations, etc. In this section, we will analyze several types of results for the induction motorwe are modeling. We encourage you to explore other types of results on your own.

The results that are relevant for this model are the torque-speed characteristic, the phasecurrents, the current in the rotor bars, the general distribution of the flux density, and eddycurrent losses in the rotor bars.

The equiflux lines and the flux density color shade plots are also useful because you can use them to check the validity of your model.

85

Chapter 4Start PostPro_2D

To see your results, from the Flux2D Supervisor, double click the Results button:

Start PostPro_2D Analyze results with PostPro_2D

Page Chapter 486

Starting Results analysis

From the Open dialogue, choose the problem to analyze and click Open:

Analyze results with PostPro_2D Start PostPro_2D

Chapter 4 Page 87

Choosing the problem to analyze

PostPro_2D will open with a display of the model geometry:

Display the full geometry

You can display various quantities as plots on the model geometry. If you wish, instead of themodel (1/4 of the motor, in this case), you can display the full geometry.

To see the full geometry, from the menu bar, click the Full Geometry button or chooseGeometry, Full Geometry:

Display the full geometry Analyze results with PostPro_2D

Page Chapter 488

Model open in PostPro_2D

Display isovalues plots

It is often useful to begin analysis with a display of the equiflux (isovalues) lines. Examining theequiflux plot is a good way to check if the results are reasonable.

The default display is 11 equiflux lines. To display more lines, click the Results Properties button

or choose Results, Properties from the menu.

Analyze results with PostPro_2D Display isovalues plots

Chapter 4 Page 89

The Display properties dialog will open.

Make sure the Isovalues tab is on top.

Then enter or verify the information in the dialog as follows:

Field Input

Isovalues

Analyzed quantity Equi flux

Support Graphic selection

Computing paramters

Quality Normal

Number 41

Display isovalues plots Analyze results with PostPro_2D

Page Chapter 490

Properties for isovalues display with 41 lines

Field Input

Scaling Uniform

OK

The properties dialog will close.

Display the isovalues plot at phase = 0

Click the Isovalues button and you will see the isovalues (equi flux) lines:


Chapter 4 Page 91

Display of equi flux lines over the whole geometry (phase = 0)

Display the plot at phase = 30

The model is displayed with the phase angle of the sources at the default value, 0 degrees. Youcan see how the flux distribution varies with time by changing the phase angle of the sources.Lets look at the equi flux lines at phase angles of 30 and 60.

To change the phase angle, open the Phase manager dialog by clicking the button or bychoosing Parameters, Phase from the menu.

The Phase dialog will open.

You can change the phase value by moving the slider, but for a precise value, you will need totype 30 in the Phase field and press Enter. You should see the slider move to the right, as shownin the following figure.


Page Chapter 492

Phase dialog

Phase set to 30 degrees

In a few seconds, the isovalues display will be updated to show the plot for a phase angle of 30degrees:

Display the plot at phase = 60

Now change the phase to 60 and press Enter:


Chapter 4 Page 93

Equi flux lines, phase = 30

Phase = 60

Again, it may take a few seconds for the plot to be updated to show the results at a phase angle of 60 degrees:

Finally, set the phase to 0 again for the other displays:


Page Chapter 494

Equi flux lines, phase = 60

Phase returned to 0 (default)

Display color shade plots on the stator and rotorregions

Now display several color shade plots, but on the stator and rotor only. Instead of selecting theregions to display each time, you can define your own groups of regions and use them for theplots.

Create a group of the stator and rotor regions

To create a group, click the icon, or select Supports, Group manager from the menu.

The Group manager dialog will open.

In the Group manager dialog, enter or verify the following:

Field Input

Filter Region

Objects available ROTOR

STATOR

Add >

Analyze results with PostPro_2D Display color shade plots on the stator and rotor regions

Chapter 4 Page 95

Group manager dialog

Field Input

Current group ROTOR

STATOR

Group name RotStat [your choice]

Notice that the regions you have chosen are displayed in their assigned color on the geometry.

Click the Create button to create the group and close the Group manager dialog.

Display color shade plots on the stator and rotor regions Analyze results with PostPro_2D

Page Chapter 496

Regions to be added to rotor-stator group

Display a flux density plot

Now use your group to display a color shade plot of the flux density in the rotor and stator.

Open the Results, Properties dialog by clicking the button or by choosing Results,Properties from the menu.

Click the Color Shade tab to bring it to the front. In the Color shade dialog, enter or verify thefollowing:

Field Input

Color Shade

Analyzed quantity |Flux density|

Support RotStat [your regions group]

Computing parameters


Chapter 4 Page 97

Properties for color shade plot of flux density

Field Input

Quality Normal

Scaling Uniform

OK

The properties dialog will close.

Then click the color shade button to see the flux density plot on the rotor and stator:

You may wish to modify the scaling of the color shade to give a better distribution of theequipotential regions. If so, in the Results, Properties dialog, instead of Uniform scaling, youmay wish to choose Min Max or Each Line.


Page Chapter 498

Color shade plot of flux density on the rotor and stator (phase = 0)

Display a saturation map (permeability)

Now display a saturation map in the rotor and stator. Click the button again to open theResults, Properties dialog.

Field Input

Color Shade

Analyzed quantity Relative permeability

Support RotStat [your regions group]


Quality Normal

Scaling Uniform

OK


Chapter 4 Page 99

Properties for color shade plot of permeability

The properties dialog will close. In a few seconds you should see the saturation map:

Create a group of the rotor bars

Now create a group of the seven rotor bars. Open the Group manager dialog:


Page Chapter 4100

Saturation map on rotor and stator regions (phase = 0)

Creating a group of the rotor bars


Field Input

Filter Region

Objects available RB1

RB2

RB3

RB4

RB5

RB6

RB7

Add >

Current group RB1

RB2

RB3

RB4

RB5

RB6

RB7

Group name Bars [your choice]

Click Create to create the group and close the Group manager dialog.


Chapter 4 Page 101

Display a power density plot in the rotor bars

Now display a plot of the power density in the rotor bars. Click the button to open theResults, Properties dialog:


Page Chapter 4102

Properties for color shade plot of power density in the rotor

bars


Field Input

Color Shade

Analyzed quantity Power density

Support Bars [your group]


Quality Normal

Scaling Uniform

OK

The properties dialog will close. You may need to click the button to display the plot:


Chapter 4 Page 103

Power density in the rotor bars

Display the current density in the first rotor bar

Now display the current density in the first rotor bar only.

First, click the Full Geometry button to deselect it, and click the Color shade button toturn off the display.

Then use the Zoom rectangle button to select an area around the first rotor bar and enlargethe display:


Page Chapter 4104

Zooming in on the first rotor bar

Now, once again, click the button to open the Results, Properties dialog.


Field Input

Color Shade

Analyzed quantity |Current density|

Support RB1


Quality Normal

Scaling Uniform

OK


Chapter 4 Page 105

Properties for current density color shade plot for first rotor bar

The properties dialog will close. Click the button to display the plot:

One can clearly see the skin depth effect in the rotor bar. The current density is concentratednear the top of the bar.


Page Chapter 4106

Current density in the first rotor bar

Computations of torque and power values

Now use the Computation manager for a series of power computations.

Open the Computation manager by clicking the button or by choosing Computation, On asupport from the menu:

The Computation manager will open:

Analyze results with PostPro_2D Computations of torque and power values

Chapter 4 Page 107

Computation manager

Compute the torque in the airgap

Begin with a computation of the torque in the airgap. The following figure shows the initialsettings for the computation:

In the Computation manager, select or verify the following:

Field Input

Filter Regions

Support AIRGAP

Properties...

Computations of torque and power values Analyze results with PostPro_2D

Page Chapter 4108

Initial settings for airgap torque computation

When you click the Properties button, the Properties dialog will open:

Make sure the Computation tab is on top. Then in the Properties dialog, enter the following:

Field Input

Quantity Torque

Component Moment

Add>

Users choice Torque/Moment


Chapter 4 Page 109

Properties for computation of torque in the airgap

Click OK to set the properties and close the dialog; you will return to the Computationmanager. Click the Compute button and you will see the results almost instantly:

Note that this result is the model motor torque (one pole or of the machine)even though you selected the AIRGAP region. The torque for the whole machine isobtained by multiplying this value by four: 4 6.723701= 26.894804

Compute the current and power supply values in each phase

Now compute the current and power supply values in each phase. The Computation managershould still be open.

Change the Filter and Support as follows:

Field Input

Filter Electrical components

Support VAC


Page Chapter 4110

Airgap torque

The following figure shows the new selections being made:

Click the Properties button and the Properties dialog will open. First, remove the torque fromthe Users choice field, as follows:


Chapter 4 Page 111

Removing Torque / Moment selection

Selecting VAC as computation support

Field Input

Users choice Torque / Moment

Remove

Then enter or verify the following:

Field Input

Quantity Circuit

Component Rms voltage

Phase voltage

Rms current

Phase current

Active power

Reactive power

Add >

Users choice Circuit/Rms voltage

Circuit/Phase voltage

Circuit/Rms current

Circuit/Phase current

Circuit/Active power

Circuit/Reactive power


Page Chapter 4112

You should see the following components selected for the computation:

Click OK and the properties dialogue will close. In the Computation manager, click theCompute button to see all the results for the voltage source VAC:


Chapter 4 Page 113

Results of circuit computations for voltage source VAC

Properties for power computations

Use these same properties to compute the values for the Phase B-A voltage source, VBA.Proceed as follows:

Field Input

Support VBA

Compute

And you should see all the results for VBA:

To calculate the total power of the motor, you can add the Active Power components computedfor the two power supplies. In this case, the total power would be -1.532098E3 + -3.020423E3or -4.552521KW. The minus sign means the source is providing power to the motor.

Compute the electric quantities for other components

With the same computation property settings, you can compute the electric quantities for all theother circuit components in just 2 steps:

1 Select the component from the drop down list in the Support field (e.g., BPA, BPB, BMC,etc.)

2 Click the Compute button.


Page Chapter 4114

Power supply values for voltage source VBA

Save the results of your computations

The results from computations you have performed through the Computation manager arewritten into the Review file (displayed at the bottom of the screen).

This file is saved by default as, for instance, Ind_Motor_Hist.txt, but the file will be overwrittenwhenever you open this problem again in PostPro_2D.

Therefore, to save these computation results, you must save them to a different file.

To do so, from the View menu choose the Save review file as... command:


Chapter 4 Page 115

Results in Review file

The Save As dialog will open:

To save your review file with the power computation results, proceed as follows:

Field Input

Save in fluxwork [choose directory]

File name IND_MOTOR_MAIN [or your name]

Save as type Postpro2D review file(*.txt)

Click the Save button to save your file.

Analyze the flux density in the airgap

We can see how the magnetic flux density varies in the airgap by plotting a curve of the fluxdensity versus position along a path in the air gap.

Create a path through the center of the airgap

To create a path through the center of the airgap, use the Path Manager.

Analyze the flux density in the airgap Analyze results with PostPro_2D

Page Chapter 4116

Saving review file (computation results)

Click the Path Manager button or choose Supports, Path manager from the menu:

The Path manager dialog will open:

You will be creating an arc of 180 degrees through the center of the airgap (1 electric cycle). Toverify the coordinates for the path, with the Path manager open, move your cursor over thegeometry model.

Analyze results with PostPro_2D Analyze the flux density in the airgap

Chapter 4 Page 117

Path manager

The cursor will appear either in the shape of a cross with a trailing line (for straight linesegments) or a drawing compass (for arcs of circles).

Enlarge the bottom of the airgap below the first rotor bar and stator slot:

Position the cursor in the middle of the airgap to see the coordinates (we used X = 58.4).

Then in the Path manager dialog, enter or verify the information as follows:

Field Input

Name Airgap [or your choice]

Discretization 200

[default color] [new color if desired]

Graphic section Arc

Numerical section New section


Page Chapter 4118

Checking coordinates for starting point of path through the airgap

When you click the New section button, the Section Editing dialog will open:

In the Section Editing dialog, enter or verify the information as follows:

Field Input

Section type Arc start angle

Center point

X 0

Y 0

Origin point

X 58.4

Y 0

Length 180

OK


Chapter 4 Page 119

Section Editing dialog to create path

Click OK to close the Section Editing dialog. You will see a part of the path displayed in theairgap:

In the Path manager dialog click the button to create the path and open the 2D Curvesmanager at the same time.


Page Chapter 4120

Path through the airgap (enlarged)

Create curves using the airgap path

Now use the path to create curves of the flux density through the airgap.

The 2D Curves manager is shown in the following figure:

Flux density: Magnitude

Begin with a curve of the magnitude of the flux density. Enter or verify the following:

Field Input

Curve description

Name FDMag

[default color] [new color, if desired]

Path

Set parameters...

Phase (deg) 0


Chapter 4 Page 121

Settings to create curve of flux density magnitude

Field Input

First axis

X axis Airgap

Second axis

Quantity Flux density

Components Magnitude

Third data

Parameter No parameter

Parameter values No value

Selection step 1

Click the Create button to create the curve. It will not be displayed yet on your screen, but youshould see its name added in the field at the bottom of the Curves manager:


Page Chapter 4122

Flux density Magnitude curve created

Flux density: Direction

Now create a similar curve for the direction of the flux density. The 2D Curves manager shoulddisplay a new default name for the curve (e.g., C...2) and a new color. You should be able tochange only the name, the color (if you wish), and the component setting, in order to create thesecond curve.

For the curve of the flux density direction, enter or verify the following:

Field Input

Curve description

Name FDDir


Path

Set parameters...

Phase (deg) 0

First axis

X axis Airgap

Second axis


Components Direction

Third data



Selection step 1

Click the Create button to create the flux density direction curve. Again, you will not see thecurve yet.


Chapter 4 Page 123

Flux density: Normal component

Next create a curve of the normal component of the flux density.


Field Input

Name FDNorm


Path

Set parameters...

Phase (deg) 0

First axis

X axis Airgap

Second axis



Page Chapter 4124

Settings for curve of normal component of flux density

Field Input

Components Normal component

Third axis



Selection step 1

Click the Create button to create the normal component curve. Remember, the curve will not bedisplayed.

Flux density: Tangential component

Next create a curve of the tangential component of the flux density.


Chapter 4 Page 125

Settings for curve of tangential component of flux density


Field Input

Name FDTang


Path

Set parameters...

Phase (deg) 0

First axis

X axis Airgap

Second axis


Components Tangent component

Third axis



Selection step 1

Again, click Create to create the tangential component curve.


Page Chapter 4126

Superimpose the Magnitude and Direction curves

Now display the flux density magnitude and direction curves together. To create a superimposeddisplay of these two curves, proceed as follows.

Click the button to open a new (blank) curves sheet. Right click on the curve sheet andopen the properties dialog.


Chapter 4 Page 127

Blank curves sheet with context menu--choosing Properties

In the Properties dialog, make sure the Selection tab is on top:

In the Selection dialog, enter or verify the following:

Field Input

Curves filter Computation

Curves available FDMag

FDDir

Add >

Displayed curves FDMag

FDDir


Page Chapter 4128

Curves properties Select dialog: choose curves to display

Click on the Display tab to bring it to the front.


Field Input

Display Superimposed

Gradations On

X Axis

Range Automatic

Scale linear

Y Axis

Range Stretched

Scale linear


Chapter 4 Page 129

Settings for superimposed curves display

Click OK to close the dialog. You should see the two curves, flux density magnitude anddirection, superimposed:


Page Chapter 4130

Curves of flux density magnitude and direction (superimposed)

Superimpose the Normal and Tangential curves

Follow the same steps to create a superimposed display of the normal and tangential componentsof the flux density. The figures below show the settings to select and superimpose these curves:

Select normal and tangential curves Settings to superimpose normal and tangentialcurves


Chapter 4 Page 131

Click OK to display the normal and tangential flux density curves:

Create a spectrum analysis of the normal component of the flux density

Next, use the Spectrum manager to display the harmonics of the normal component of the fluxdensity.

Click the button or choose Computation, 2D Spectrum manager from the menu:


Page Chapter 4132

Normal and tangential flux density curves (phase = 0)

The Spectrum manager dialog will open:

Enter or verify the following settings for the spectrum analysis:

Field Input

Analyzed curve FDNorm

Between 0

and 183.468994

Part of cycle described Full cycle

Create this rebuilded curve too [check box to enable display of normal component curve]

Spectrum

Harmonics number 30

Spectrum scale Linear


Chapter 4 Page 133

Spectrum manager

Field Input

Display the DC component line [check if desired]

Name Spec_FDNorm


Click the button to create and display the spectrum and the normal component curve:

One can observe important 5th, 13th, 15th, 17th and 19th harmonics.


Page Chapter 4134

Spectrum analysis of normal component of flux density through the airgap

To clarify the spectrum display, you can change its properties. Right click on the legend of thespectrum and choose Properties from the context menu:

In the properties dialog, you can change the legend text, the form of the curve, the line width andcolor. Change the settings as you wish (for example, our spectrum uses a line width of 3).

Click OK to apply your changes and close the dialog.


Chapter 4 Page 135

Changing spectrum properties

Plot the flux density at phase = 30

Now create new flux density curves with the phase angle at 30 degrees. The following figuresshow the settings for the normal and tangential curves of the flux density.


Page Chapter 4136

Settings for flux density normal component curve at phase = 30

Be sure to change the phase angle to 30 for both curves.


Chapter 4 Page 137

Settings for flux density tangential component curve at phase = 30

Once you have created both curves, superimpose them for a display like the following:

The movement of the peaks of the magnetic flux density curve can be seen clearly following themovement of the power supply traveling wave.

Current distribution in the rotor bars

Another interesting result to examine is the current distribution in the rotor bars. This can befound by plotting the current density curve along a radial path inside the rotor bar.

Display the model geometry again by returning to the first sheet (click the"Geometry[IND_MOTOR.TRA:1]" tab at the top of the window).

Current distribution in the rotor bars Analyze results with PostPro_2D

Page Chapter 4138

Normal and tangential flux density curves, phase = 30

Enlarge the area around the first rotor bar:

Create a path through the first rotor bar

Create a path through the first rotor bar as follows.

Open the Path manager with the button, or choose Supports, Path manager from the menu.

Analyze results with PostPro_2D Current distribution in the rotor bars

Chapter 4 Page 139

Enlarging view of first rotor bar

The Path manager dialog will open.

Because the rotor bar is a relatively small area, we use a discretization of 50 points along the path,instead of the default 200, but you may choose any number you wish.

In the Path manager, enter or verify the initial information as follows:

Field Input

Name Bar1

Discretization 50


Graphic section Segment


Page Chapter 4140

Path manager: RB1

Now, instead of entering coordinates, however, you can just draw the path through the rotor bar,as shown in the following figure.

Click a point at the left edge in the middle of the bars outline for the starting point, and drag the

cursor to draw a line through the center of the bar. Click again to end the line.


Chapter 4 Page 141

Drawing the path through the first rotor bar

You should see a line through the bar as shown in the following figure.

Then in the Path manager, click the Create button to create the path.

Create a curve using the rotor bar path

Now create curves of the magnitude and phase of the current density along the path through the

rotor bar. Open the 2D Curves manager with the icon:


Page Chapter 4142

Path through first rotor bar

For the current density magnitude curve, proceed as follows:

Field Input

Curve description

Name Bar1_IDensM

[default colot] [new color, if desired]

Path

First axis

X axis Bar1

Second axis

Quantity Current density

Components Magnitude

Create

Click the Create button to create the curve. (Remember, the curve will not be displayed.)

Now modify the settings to create a curve of the current density/phase. You should be able toenter only a new name, a new color (if you wish), and then select the Phase component tocreate the new curve.


Field Input

Curve description

Name Bar1_IDensP


Path

First axis

X axis Bar1

Second axis

Quantity Current density

Components Phase

Create


Chapter 4 Page 143

Again, when you click the Create button, the curve will be added but not displayed.

Open a new blank curves sheet and superimpose the curves for a display like the following:

The outer end of the rotor bar has a higher current density than the inner end because of the skineffect.


Page Chapter 4144

Magnitude and phase of current density through first rotor bar

Save and close PostPro_2D

This concludes our magnetodynamic analysis of the induction motor at rated slip. To save theanalysis supports (groups, paths, etc.) and the curves you have created, proceed as follows.

When you are ready, click the Save button to save your work.

Then close PostPro_2D by selecting File, Exit from the menu:

You will return to the Flux2D Supervisor.

Analyze results with PostPro_2D Save and close PostPro_2D

Chapter 4 Page 145

Closing PostPro_2D

Parameterized solution at differentspeeds

We would now like to analyze the machine running at different speeds. This involves redefiningthe slip specified when entering the physical properties with Pre

Documents

Tutorial Induction Machine Calculations