HEV TCP Task 26 Workshop 9: Wireless Charging for EVs (6-7 Nov. 2018 in Detroit, Michigan USA)
“NREL’s Managed WPT Experiences and Lessons Learned”
PresenterAhmed Mohamed
Transportation and Hydrogen Systems Center, NREL.
NREL | 2
Introduction/NREL’s Vision for Demonstrating WPT for EV
Description of 25 kW WPT system at NREL’s Shuttle
EMF Testing of On-Vehicle WPT System
Monitoring and Control of the Wireless Charging
Description of WPTsim Tool for WPT design
Design of Greenville AMD Project using WPTsim
Conclusions/Opportunities
NREL | 3
Dyna
mic
WPTQua
si-dy
nam
ic W
PT Stat
iona
ry W
PT
vehicle pad
ground pad
PPM
https://www.nbcnews.com/mach/mach/futuristic-roads-may-make-recharging-electric-cars-thing-past-ncna766456
https://www.nbcnews.com/mach/mach/futuristic-roads-may-make-recharging-electric-cars-thing-past-ncna766456
NREL | 4
NREL | 5
Wirelessly Charged Electric Shuttle
Momentum Dynamics WPT system
3ϕ ACsupply
Filter EVbattery
Primary controller Secondary controller
Radio munications
vehicle pad
ground pad
PPM
o Full electric on-demand serviceo 16 passengero 62.1 kWh battery capacityo 100 miles rangeo 7600 curb weight, including VAo 6.6 kW on-board conductive charger
o 35.5”x35.5”x2.25” (900x900x57 mm) symmetrical square pads
o 25 kW maximum power transfero 20 (19-21) kHz nominal operating
frequency.o Automatic alignment capability.o 5”-9.5” (125-240 mm) airgap
NREL | 6
https://www.narda-sts.com/en/http://www.eenewsautomotive.com/news/one-test-system-analysing-electromagnetic-fields-5-hz-60-ghz
Test Methodology
1. Define coordinates.
2. Define a marked safety perimeter.
3. Identify the worst misalignment condition (X, Y, Z, pitch, roll and yaw).
4. Define test zones and pointsRegion I: Under the vehicleRegion II: Around and above the vehicleRegion III: Inside the vehicle
5. Define the standard limits for each zone (2010 ICNIRP)
Coupler Offset & Gap Max Magnetic Field Max Electric FielddX dY dZ Location B (µT) Location E (V/m)
+max +max max+max -max max-max +max max-max -max max
“J2954A (WIP) Wireless Power Transfer for Light-Duty Plug-In/ Electric Vehicles and Alignment Methodology - SAE International.”
EHP-50D,Narda
https://www.narda-sts.com/en/http://www.eenewsautomotive.com/news/one-test-system-analysing-electromagnetic-fields-5-hz-60-ghz
NREL | 7
X-axis
Y-axis
VA
X-axis
Y-axis
VA
X-axis
Y-axis
VA
X-axis
Y-axis
VA
X-axis
Y-axis
VA
(a) (b) (c)
(d) (e)
EMFs around the vehicle (zone II)
EMFs before/during alignment (Low Power Excitation)
Y-axis
X-axis
GA
×
×
×
×
×
× ×
×
× × × × × ×
Z
test
regi
on
9"
9"
240"shuttle
20" 20"8.5"
driver’s seat
36"
36"
76"
Y-axis
X-axisVA &GA
front
back
test
regi
on
Z× P1
6'
6'
6'
6'
Misalignment Max Brms (µT) Max Erms (V/m)Position I 16.661 1.7414 Position II 18.380 2.4091Position III 17.696 2.5345 Position IV 17.152 1.7147 Position V 18.526 2.0853
NREL | 8
× × × × ×
×
×
×
×
× × × bus
inside
seat
VA
bus outside Y’-axis
X’-axis
A
B
C
EMFs inside the vehicle (zone III)
Test Point Max Brms (µT) Max Erms (V/m)PA 0.0328 0.0633 PB 0.0068 0.0380 PC 1.0362 0.0257
Magnetic field along X’-axis at a height of 27.25” from the floor of the bus
Magnetic field along Y’-axis at a height of 6.25” from the floor of the bus
Driver seat test points Over VA test points
NREL | 9
NREL | 10
NREL Intelligent Campus Integrates:
o RESs
o ESSs
o Building loads
o EVSEs- AC level 2- DC FC (50 kW)- Wireless Charger (25 kW)- Bidirectional EV
NREL | 11
Objective: ‘smart’ integration of wireless charger with surrounding infrastructure on NREL campus (e.g. Renewable Generation, Loads, other EVSEs, etc. )
Momentum Dynamics Grafana System
vehicle pad
ground pad
PPM
Charge Control
SOCVehicle status
NREL’s campus load
Charge decision
SOCVehicle status
Power transfer
NREL’s Campus Load
Block diagram for the data-flow of the wireless charging control
NREL | 12
Cloudy day results: lack of PV generation
0 5 10 15 203500
4000
4500
PL
(kW
)
load
limit
0 5 10 15 20-500
0
500
PL
(kW
) loadlimit
0 5 10 15 200
5
Alig
n
0 5 10 15 200
50
100
SOC
(%) SOC
Max SOC
Min SOC
0 5 10 15 20
Time (hr)
0
1
2
sign
al
0 5 10 15 20
2000
4000
PL
(kW
)
load
limit
0 5 10 15 200
1000
2000
3000
PL
(kW
) loadlimit
0 5 10 15 200
5
Alig
n
0 5 10 15 200
50
100
SO
C (%
)
SOC
Max SOC
Min SOC
0 5 10 15 20
Time (hr)
0
1
2
sign
alNice day results: lots of PV generation
NREL | 13
NREL | 14
It is a design optimization tool that incorporates driving data, vehicle data with charging infrastructure parameters (conductive or wireless).
SpeedPositiongrade
Driving data
Vehicle’s data
BatteryMotorDimensionsetc.
0 0.5 1 1.5 2 2.50
10
20
30
Spee
d (m
ph)
Type 1
WPT location 1
WPT location 2
WPT location 3
WPT location 4
WPT location 5
WPT location 6
Type 4
Type 4
0 0.5 1 1.5 2 2.5
Time (hr)
-200
-100
0
100
200
Bat
tery
pow
er (k
W)
65
70
75
SOC
(%)
Charger’s data
PowerEfficiency
Conductive
Wireless
PowerEfficiencyPositionsLength
WPTsim
Evaluate Fitness- Charge sustaining- Min. Battery capacity- Min. charging infrastructure cost
Generate variables- Battery capacity- Track positions- Track length- Rated power
It is capable of providing optimum design of wireless infrastructures (stationary, dynamic and quasi-dynamic) for certain road scenario.
It is utilized to provide designs for multiple scenarios such as:
NREL’s circulator shuttle. Greenville AMD Project
Optimization Search Algorithm
NREL | 15
WPTsim
LtLr
Wr Wt
PnP
n
Wr
S
d
d
Travel direction
Lane direction
T1 T2R
16 passenger, curb weight 3500 kg, 36 kWh battery capacity and about 45 mph maximum speed
GRT AES
Phase 0
Phase 1
0 1 2 3 4 5 60
50
0 1 2 3 4 5 60
50
Sp
eed
(m
ph
)
0 1 2 3 4 5 60
50
0 1 2 3 4 5 6
Time (hr)
0
50
-82.35 -82.345 -82.34 -82.335 -82.33 -82.325 -82.32 -82.315 -82.31
Longitude
34.818
34.82
34.822
34.824
34.826
34.828
34.83
34.832
34.834
34.836
34.838
latit
ude
AET11
AET12
AET13
AET14
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.50
20
40
Spe
ed (m
ph)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
Time (hr)
-100
0
100
Bat
tery
pow
er (k
W)
60
80
100
SO
C (%
)
GRT, AET11 with 17 WPT positions (60 kW and 155 m track at each position).
1.6 1.65 1.7 1.75 1.8 1.85 1.9 1.95 20
10
20
30
40
50
Spee
d (mp
h)
1.6 1.65 1.7 1.75 1.8 1.85 1.9 1.95 2
Time (hr)
0
Batte
ry po
wer (
kW)
80
SOC
(%)
NREL | 16
Parameter Optimal value# wireless chargers 11 out of 17Positions [3 4 5 7 8 9 11 13 14 15 17]Power 80 kWBattery capacity 12 kWh# segments per Track 25 (125-meter track length)
Optimal driving performance
Optimal WPT positions
Optimal key design parameters
-82.35 -82.345 -82.34 -82.335 -82.33 -82.325 -82.32 -82.315 -82.31
Longitude
34.815
34.82
34.825
34.83
34.835
34.84
Latit
iude
Map of travel with highlighted WPT segments
Full Drivecycle
Segment 1 boundary
Segment 2 boundary
Segment 3 boundary
Segment 4 boundary
Segment 5 boundary
Segment 6 boundary
Segment 7 boundary
Segment 8 boundary
Segment 9 boundary
Segment 10 boundary
Segment 11 boundary
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.50
20
40
Spee
d (m
ph)
Type 1
WPT location 1
WPT location 2
WPT location 3
WPT location 4
WPT location 5
WPT location 6
WPT location 7
WPT location 8
WPT location 9
WPT location 10
WPT location 11
Type 4
Type 4
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
Time (hr)
-100
0
100
Batte
ry p
ower
(kW
)
50
60
70
80
90
SOC
(%)
– Optimization Variables:– Position of each wireless charger.– Wireless charger power.– EV’s battery capacity.– Number of track segments (track length).
– Optimization Objectives:– Minimum battery capacity.– Minimum charging infrastructure cost.– Achieve charge sustaining operation.
NREL | 17
Extra effort is required for demonstrating the WPT technology in real world scenarios starting with closed campus scenarios.
Collecting data from real-world projects, including NREL’s shuttle one, to be utilized for better understanding the technology, control design and validating design tools.
Updating and utilizing WPTsim tool for analyzing more complex charge design scenarios (e.g. interstate, urban and rural roads).
Working to have an EasyMile autonomous shuttle operating at NREL campus with the possibility to install a wireless charger to it.
www.nrel.gov
This work was authored by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy,LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided by U.S.Department of Energy Office of Energy Efficiency and Renewable Energy Vehicles Technologies Office. The viewsexpressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S.Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S.Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the publishedform of this work, or allow others to do so, for U.S. Government purposes.
NREL/PR-5400-72805
NREL's Managed WPT Experiences and Lessons LearnedOutlinesVisions of WPT for EVStationary Wireless Charging: 25 kW Wireless Charger at NREL’s ShuttleWPT on NREL’s CampusEMF Testing for In-Vehicle WPT SystemEMF Test ResultsEMF Test Results
Wireless Charger Operation: Monitored and ManagedNREL’s Intelligent Campus Energy Management PlanWireless Charging Operation: ControlResults of the Wireless Charging ControlDynamic Wireless Charging: Feasibility Analysis of DWPT for Autonomous Vehicles at AMDsWPTsim Tool: Wireless Charging DesignGreenville Automated Mobility District (AMD):� WPTsim Scenario AnalysisOptimization Results of Greenville AMD
Conclusion/Opportunities