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