Dr J Rhett Mayor's of President of DHX Machine and Georgia Institute of Technology's talk at CWIEME Berlin 2018

1. Direct-winding Heat Exchange
Cooling Technology
(DwHX™)
Dr. J.Rhett Mayor
President, CEO
DHX Electric Machines, Inc.
Associate Professor
George W. Woodruff School of Mechanical Engineering,
Georgia Institute of Technology

2. “…it will do the work of the world. ”
Nikola Tesla
30 hp
Induction Motor
230 V, 3φ
90.4%
330 lbs
7110 TWhr (2011)
4.5B barrels of oil

3. 30 hp
Surface-Mount Permanent
Magnet Synchronous Motor
230 V, 3φ
94%
12 lbs
Increased Power Density | Increased EMDS Efficiency
DwHX Cooling TechnologyTM

4. 30 hp
Surface-Mount
Permanent Magnet
Synchronous Motor
230 V, 3φ
94%
12 lbs
“More Power. Less Motor. ”
DHX Electric Machines, Inc.

5. Outline
1. DwHX Cooling Technology™ – by the physics
2. Hawk Series
3. E-Mobility, Sustainable Mobility & The Future of Electric Traction
4. Application Spaces – Opens Possibilities™

6. Traditional Water Cooling Technology
Water Jacket Direct Lamination Cooling
Frame
Tooth
Slot
Stator
Windings
Conduction Paths
Rotor
Conduction Paths
Flow
Channel
Flow
Channel

7. DwHX Cooling TechnologyTM - by the physics
R-θ Design plane
Power = Torque x Speed
Power:
Ambient Rejection:
Internal Transport:
Internal losses:
Where:

8. No load Load
5,000
rpm
7,500
rpm
10,000
rpm
SRM Finite Difference Predictions

9. DwHXTM Cooling Technology
Rotor
Permanent
Magnets
Windings
Stator
Direct winding Heat
eXchanger
Flow
Channel

10. Active Thermal Capacitance
• Ultra high torque density for peaking loads can be achieved through
optimal design and existing thermal management techniques
• Sustained periods of peaking power significantly increases the thermal
management challenge as the thermal capacitance of the frame is
insufficient
• Active thermal capacitance enables the active control of motor thermal
capacitance using micro-feature heat exchanger technology

11. Micro feature enhanced convective
thermal transport from the
winding bundle:

12. DHX Design & Analysis Capabilities
[1] J. R. Mayor and S. A. Semidey, "Generic electric machine thermal model development using an automated finite difference approach," in 2009 IEEE International Electric Machines and Drives Conference, IEMDC '09, May 3, 2009 - May 6, 2009, Miami, FL, United
states, 2009, pp. 137-143.
[2] S. A. Semidey, D. Yao, J. R. Mayor, R. G. Harley, and T. G. Habetler, "Optimal Electromagnetic-Thermo-Mechanical Integrated Design Candidate Search and Selection for Surface-Mount Permanent-Magnet Machines Considering Load Profiles," Industry
Applications, IEEE Transactions on, vol. 47, pp. 2460-2468, 2011.
[3] S. A. Semidey and J. R. Mayor, “Parametric Thermal Estimation of Electric Machines using a Finite Difference Approach,” Submitted for inclusion in PEMD 2014
[4] S. A. Semidey and J. R. Mayor, “Design and Optimization of SMPM Electric Machines Incorporating Direct Windings Heat Exchangers,” Submitted for inclusion in PEMD 2014
Thermo-Mechanical &
Electromagnetic FEA
Custom thermo- mechanical-
electromagnetic design
optimization tool
[1]-[4]
Parametric CAD Solid Modeling
Crane 4000

13. Hawk Series

14. Hawk20
(48V) traction motor
40 Nm max torque
18.4 kW [25 hp] max power
5.4 kg [12 lbs]

15. Hawk40
(96 VDC) traction motor
80 Nm max torque
36.8 kW [49 hp] max power
9.2 kg [20.2 lbs]

16. Hawk60
(144 VDC) traction motor
120 Nm max torque
55.3 kW [74 hp] max power
11.9 kg [26.2 lbs]

17. LOGISTICS
HAWK20
MOTOR + KiT

18. EV● “The Future of Electric Vehicles is
Golf Carts, Not Tesla” – Thomas
Bartman, Harvard Business
Review, May 14, 2015
● Bottom of the market with low-
speed EVs built of golf-cart
platforms is experiencing huge
growth.
○ ~100,000 vehicles per year
USA
○ ~500,000 vehicles per year
China
● Electric Utility Vehicles (EUVs)
experiencing similar gains due to
incentives and operating
advantages in congested city
delivery businesses.
● MOTOR OPPORTUNITY SPACE –
Compact, high-torque low-
voltage traction motors in the 10-
30 hp range

19. The Hawk 20 powered
golf cart 25mph.
With regenerative braking.
Demonstrated 55 mile
range.
More Power, Less Motor.TM

20. 100% Green Personal Mobility
Capability of
DHX motors to
provide high
kVA on low
voltage bus
(48Vdc) opens
possibility for
combined solar
& wind-turbine
based fast-
charging
towers.

21. OPENS POSSIBILITIESTM
Vertical Traction
HVACR
Marine
Green Power
Aerospace
Factories of the Future
DwHXTM Cooling Technology -

22. DHX Electric Machines, Inc.
1101 HWY 124, Bldg 5
Hoschton, Georgia 30548
U.S.A
@DHXmachines
P: +1 (678) 900-1074
e: info@dhxmachines.com
www.dhxmachines.com