1. PExprt Modeling Procedure

2. Overview
Power Electronics Expert (PExprt)® is an interactive, performance based design tool that uses analytical expressions to design magnetic components, such as transformers and inductors.
Standard libraries of magnetic cores, bobbins, insulators, and conductors allow you to define the model to your exact specifications.
Using PExprt, you can design: inductors, multi-winding transformers, coupled inductors, and flyback components.
Optimize constructive parameters, such as core size, core material, number of turns, air gap length, wire gauge, and number of parallel turns.

3. Overview (cont.)
Calculate performance parameters, such as winding losses, core losses, flux density, DC and AC resistance, Irms currents, magnetizing inductance, leakage inductance, and temperature rise.
Consider complex effects, such as skin and proximity effects, fringing flux near the air-gap for energy calculations
Calculate winding losses based on FEA field solution and core losses.
PExprt also includes the Pemag modeling module, a powerful magnetic analysis module based on finite element analysis. This module conducts a detailed analysis of geometry, frequency, and material
Generate model netlists for SIMPLORER®, Maxwell SPICE®, PSpice®, and Saber® electrical simulators to perform a complete system simulation of the entire device.

4. Step 1: Choose device type
Choose the appropriate device type (1 of 12 options) and assign appropriate inputs
Inductor, Transformer, Coupled Inductor and Flyback
Choose either Waveform based or Converter based 1 2 3 4 5 6 7 8 9 10 11 12

5. Waveform Based Inductor (option 1)
Inputs:
Voltage Waveform
Voltage Value
Iaverage
Frequency
Inductance
Duty Cycle
Conduction Mode
Note: Inductance is known

6. Converter Based Buck Inductor (option 2)
Inputs:
Input Voltage
Output Voltage
Output Power
Current Ripple
Ripple %
Note: Inductance is unknown

7. Waveform Based Transformer (option 3)
Inputs:
Primary Voltage
Turns Ratio
Power
Frequency
Voltage Shape
Duty Cycle
Voltage Waveform

8. Converter Based PushPull Transformer (option 9)
Inputs:
Input Voltage
Output Voltage
Output Power
Switching Freq.
Duty Cycle

9. Waveform Based Coupled Inductor (option 10)
Inputs:
Input Voltage
Average Current
Inductance
Turns Ratio
Frequency
Duty Cycle
Conduction Mode

10. Waveform Based Flyback (option 11)
Inputs:
Input Voltage
Average Current
Inductance
Turns Ratio
Frequency
Duty Cycle
Conduction Mode

11. Converter Based Flyback (option 12)
Inputs:
Input Voltage
Switching Frequency
Output Voltage
Output Power
Ripple Current
Turns Ratio
Waveform

12. Step 2: Select Design Inputs
The design inputs vary depending on the device being modeled:
Gap, Geometry (concentric, planar, toroidal), Bobbin, Permeability, Ventilation type, Radiation and Convection, Ambient Temperature, Winding Setup (1D or 2D), Winding Efficiency, Fringing gap energy, Maximum parallel turns, fixed gap, margin tape, limit values

13. Step 3: Modeling Options
The modeling options help to improve the accuracy of the results:
Winding losses calculation, Core losses calculation, Optimization method, listing results, apply restrictions, number of harmonics

14. Step 4: Select Library
PExprt contains seven manufacturer libraries: AVX, Epcos, Ferroxcube, Magnetics, Micrometals, Steward, and TDK
Only one library can be used for a given design
To select a library, highlight it and drag it down to the Design Library icon
Once copied to the Design Library, the elements can be modified

15. Step 5: Select Core Shape
PExprt contains eleven cores shapes
For Concentric and Planar, choose: POT, RM, EE, EI, ETD, EFD, UU, EP, PQ, or UI
For Toroidal, choose only toroidal cores

16. Step 6: Select Core Size
To select a core, right mouse click on the core displaying a symbol
To modify core properties or dimensions, double click on the core

17. Step 7: Select Bobbin
If used, select a bobbin to match the core used

18. Step 8: Select Conductors
PExprt contains five conductor types, depending on the geometry chosen (concentric, planar, or toroidal)
For Concentric, choose: Litz, Round, Foil, or Square
For Planar, choose only planar
For Toroidal, choose Litz or Round

19. Available Conductor Types
Litz
Foil
Planar
Round
Square

20. Step 9: Select Core Material
PExprt contains two basic material types: iron powder and ferrite
For each core material, the electrical properties and core loss parameters can be specified

21. Step 10: Start the Design Process
Use either“Calculations/Start Design Process” or click on the button at the toolbar

22. Several of each component are chosen, instead of the complete library
Automatic selection of core shape, wires, and core material
If you do not specify the core shape, conductors, and core material, the program will do this automatically.
Several of each component are chosen, instead of the complete library

23. A progress bar shows the status of the design procedure.
Designing the component…
A progress bar shows the status of the design procedure.
When completed, the number of valid designs and number of attempted designs are listed.

24. Step 11: Explore the list of results
To sort a particular column, such power loss, click on the top of the column

25. Step 12: Explore the performance results
Select Performance Results to examine the losses, inductances, resistance, flux density, incremental permeability, and temperature

26. Step 13: Explore the construction results
Select Construction Results to see the chosen: core size, bobbin, core material, gap, wire, winding turns, and parallel paths
Double click on core size, bobbin, core material, or wire to check the details of the component

27. Select Reports > Complete Report to see summary of design
Step 14: View Complete report
Select Reports > Complete Report to see summary of design
| PExprt Magnetic Component Report |
| Generated by PExprt |
| Copyright UPM-Ansoft |
| Version |
| Waveform Description |
Square Voltage Waveform
Positive Voltage Value: V
Negative Voltage Value: V
Frequency: 70 kHz
Continuous Conduction Mode
Average Current Value: A
Current Ripple Value: A
Specified Inductance Value: uH
Duty Cycle (ton/T): 24 %
| Design Inputs |
Gap at central leg only
Use Bobbin: No
Planar Component
2D Winding strategies are feasible
Maximum number of parallel turns: 10
Heat transfer method: Normal
Winding efficiency defined by turns spacing:
Intralayer spacing: 25 um
Interlayer spacing: 25 um
Window filling defined by window occupancy (Wire area/Window area):
| Modeling Options |
Winding losses calculated accounting for skin effect
Number of harmonics to be considered: 512
Optimization of solutions for each parallel
| Design Performance Results |
Losses Distribution:
Winding Losses: W
Core Losses: mW
Total Losses: W
Flux Density:
Variation of B: mT
Maximum B: mT
| Design Constructive Results |
Design Library: Ferroxcube_Design
Core Size: E71/33/32
Core Material: 3F3
Bobbin: None
Wire: Copper_70um_7mm
Number of Turns: 4
Number of parallel turns: 10
Gap: um

28. Select Modeler > Generate Model to create a netlist for the design.
Step 15: Create a netlist model
Select Modeler > Generate Model to create a netlist for the design.
Choose Analytical, FEA with capacitance, or FEA without capacitance for the model type.

29. Step 16: View Simplorer Netlist
Choose Modeler > View Netlist > Simplorer to see the netlist for the design

30. Step 17: Import into Simplorer