James Goss's EV Momentum Summit, Berlin 21 June 2018

1. Simulation based eMachine design
for EV powertrains

2. 2
Overview
• Introduction to Motor Design Ltd
• Multi-physics simulation and design
• Practical engineering approach
• Systems modelling and engineering workflow
• Conclusion

3. 3
Motor Design Ltd (MDL)
Motor-CAD Software
➢ Develop Motor-CAD software for electric motor design
➢ High level of customer support and engineering know-how
➢ Motor design software is developed by motor engineers
Consultancy
➢ Design, analysis & training.
Research
➢ Involved in collaborative government/EU funded research projects:
➢ Concept_e – Prototype Electric vehicle development with Jaguar Land Rover (JLR)
➢ HVEMS – High Volume E-Machines Manufacturing Supply. Make-Like-Production prototyping facility in the UK with JLR
➢ Tevva – Design of SRM motors for Trucks
➢ ReFreeDrive – Rare Earth Traction motors with improved performance and lower cost (Induction and Reluctance Motors)
➢ ELETAD – Helicopter electric tail rotor
➢ Collaborate with Universities worldwide to develop electric machine modelling techniques and create validation data.

4. 4
Introduction
• Development of an EV powertrain is a complex systems problem
• Achieving an optimal system design requires evaluation of many different
concepts and topologies as well as detailed understanding of the system
interactions.
• These interactions are typically cross specialism or discipline, involve different
teams and often require multi-physics analysis.
• Design and simulation tools are crucial to evaluating different design
topologies as well as identifying and understanding important system
interactions.

5. 5
Motor-CAD Software: Multi-physics machine design
➢ Leading dedicated multi-physics tool for design and
simulation of electric motors
➢ Motor-CAD EMag, Therm and Lab modules are
developed to enable fast and accurate analysis in
one integrated software
➢ EMag: A fast 2D finite element module for
accurate electromagnetic and electrical
performance predictions.
➢ Therm: Combines a lumped circuit and finite
element thermal calculation for optimising the
cooling system of a machine.
➢ Lab: Provides efficiency mapping and duty cycle /
drive cycle transient outputs within minutes

6. 6
Motor-CAD EMag
➢ Motor Types:
➢ BPM (inner & outer rotor)
➢ Induction
➢ Synchronous reluctance
➢ Switched reluctance
➢ Synchronous wound field
➢ Very fast and easy to set-
up a design and do
complex analysis
➢ Comprehensively validated
Winding eddy current loss

7. Motor-CAD Therm: Thermal Network
• Thermal and flow network analysis
• 3D network automatically generated
• 20 years of embedded experience in thermal modelling of eMachines

8. 8
➢ Facilitates very fast and accurate calculation of the motor electromagnetic and thermal
performance over the full torque/speed envelope by use of intelligent loss algorithms
➢ Suited to applications such as traction applications that have complex duty cycle loads
➢ Automated calculation of optimum phase advance angle for maximum torque/amp or
maximum efficiency control
Motor-CAD Lab: Virtual Testing Laboratory
Efficiency map with drive cycle overlaid Loss v Time calculated from
efficiency map to be input into
thermal model
Temperature v Time for a particular
drive cycle

9. Examples of Traction Motors in Motor-CAD
➢Can model all common EV traction motors types in Motor-CAD
➢Leaf, Tesla, Prius, Accord, Volt, i3, Zoe, ….
➢Different winding types
➢Distributed, Tooth Wound, Bar/Hairpin, Litz …
➢BPM, Induction, Wound Field, Reluctance, ….
➢Different Cooling types
➢Air Cooled, Water Jacket, Oil Spray, …..
TESLA LEAF PRIUS ACCORD
i3

10. 10
Motor-CAD: Drive cycle simulation
➢ The operation of these machines is very dynamic and consideration of performance across
the full torque/speed operating envelope is required
➢ Modelling tools need to support this, Motor-CAD is a unique solution on the market for
this type of analysis
➢ It allow machine efficiency to be optimised over standard operating cycles and sized for a
worst-case cycle, giving minimum system size and cost
Vehicle
Speed Profile
Motor/Generator: Time
vs Torque vs Speed
Motor/Generator:
Loss vs Time
Motor/Generator:
Temperature Vs Time

11. 11
Motor-CAD: Engineering tool
➢ Typically there are a number of unknowns when designing or
modelling electric machines, often influenced by the
manufacturing process, for example:
➢ The influence of the manufacturing process on the loss coefficients in the electrical
steel laminations
➢ The thermal interface resistance between the stator lamination and housing
➢ The ratio of air to impregnation in the winding
➢ Motor-CAD includes embedded knowledge on these aspects
built up over many years using practical/experimental
experience

12. 12
Motor-CAD: Engineering tool
➢ Example on-going project:
➢ Quantify the impact of different types of oil spray cooling
on a hairpin wound machines
➢ Oil Mist from spray nozzles
➢ Oil Drip from tube above winding
➢ Oil Jet from ring offset axially from the machine
➢ Oil thrown from rotor due to centrifugal force
➢ This is used to provide useful information on the set-up of
oil cooling models

13. Motor-CAD: Systems Engineering and workflow
➢ Interaction between other powertrain components is
handled through coupling with other specialist tools
➢ Combined NVH response of motor and gearbox using Motor-CAD and Romax
designer
➢ Combined inverter and motor behaviour through model export to Simulink
Simscape
➢ Vehicle thermal system behaviour analysed through co-simulation with GT-
Suite
➢ Partnership with Ansys provides coupling to high power numerical
simulation:
➢ 3D FEA for analysis of end-effects with Ansys Maxwell
➢ CFD for analysis of heat transfer due to fluid flow with Fluent
➢ Mechanical stress and vibration analysis with Ansys Mechanical

14. Motor-CAD Links to ANSYS for Improved Design Workflow
Concept Design to System Validation
Design Tool
for electrical
machines
Advanced Magnetics Modeling
Maxwell 2D & 3D
Lab
Efficient Motor Design Toolkit
Motor-CAD
EmagThermal
NVH, Cooling
Mechanical & CFD
Control logic, software
System Validation
3D Physical Validation
Concept Design System Validation
Lab
Design Analysis Operation

15. 15
• OptiSlang is a robust design optimisation
platform its offers sensitivity analysis,
optimization and robustness evaluation
• Previous state-of-the-art electric motor
design optimisation techniques focus on only
analysis of machines at single operating
points and usually only account for
electromagnetic operation.
• This coupling will allow the full power of
Motor-CAD to be used in an optimisation
procedure.
• This will include peak performance,
continuous performance and drive cycle
analysis to be included in the cost or
constraint functions.
Motor-CAD – OptiSlang Coupling
http://www.proteanelectric.com/specifications/

16. 16
Summary
• E-machine development requires iteration of many design
variants with other system components to achieve an optimal
system solution
• These e-machine design variants need to be analysed
considering electromagnetic, thermal and mechanical
behaviour over the full operating range
• A combined physics and practical based experience approach
is crucial
• Modelling of the interaction between components is required
to understand the performance and capability of the overall
system.

17. Motor Design Ltd
5 Edison Court | Wrexham | LL13 7YT | UK
Tel. +44 (0)1691 623305