Transcript Update of SAE J2908 Activities

Update of SAE J2908 Activities
Mike Duoba
Argonne National Laboratory
19 October 2015
1
SAE J2908 History
J2907 – Motor Ratings
J2908 – System Rating
• J2907/J2908 originally given SAE “J-doc” numbers more than 10 years
ago, due to lack of progress, committee was tabled
• 2013: some meetings were held to restart J2907
• Dec 2013: J2908 committee started recruiting members,
regular monthly meetings in 2014 and 2015
• July 2014: Argonne started doing exploratory chassis dyno testing
• March – July 2015: rented hub dyno for testing
2
Basic Elements of J2908
good progress
1. Run a Test
good progress
2. Collect Data
problems
3. Report Rating
–
Based upon test data & possibly other information
3
1. Run Test
• Prep requirements varied slightly for each HEV design (SOC and Temps)
• Found a few test procedure options to best achieve peak total
powertrain power for different types of HEVs
• Hub dyno and chassis dyno (w/axle torque) were found to be equivalent
Hub Dyno
or
Chassis Dyno
or
Wheel or axle torque sensor needed
for power direct power measurements
4
Different Test Types Were Developed for
Different Powertrain Operation
Fixed-Speed mode
Road load mode
Low-Inertia, High ABC loads
Road load mode
Notes: - When speeds are changing quickly, inertia effects lower measured power.
- Fixed Speed and Terminal Velocity tests are preferable.
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2. Collect Data
• Measure DC electric power
– from battery
– From accessories
• Monitor Powertrain Parameters
– Engine: RPM, MAP, MAF, injection timing, reported torque
– Other: gear #, powertrain states, reported RPM and torques of motors
• Measure Axle or Wheel Power
– May or may not be required
Current and Voltage Measurements
Vehicle Network Data
Dynamometer Data
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3. Report Rating
• J2908 is Currently stuck here!
• Conflict between two objectives:
– Value to Consumer (rating allows comparisons to other vehicles)
– Ability to Verify (is information from OEM required?)
• Reporting options do not satisfy both objectives
Ability to Verify 
 Useful to Consumer (can compare to ICE Vehicles)
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From What Information is the
“Net System Power” Rating Reported??
Three methods emerged
Battery
Acc
Engine Powerestimated +
Method
1
DC Powermeasured
MG2
MG1
Eng
S Shaft Powersestimated Method 2
Any
Configuration
Axle/Wheel Powermeasured Method 3
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Deciding on a Solution
• If verifiability is of most importance, Method 3 will provide best data
without reliance on estimations
• If 100% compatibility with conventional vehicle (engine-only) ratings are
of most importance, Method 2 provides that rating
• Method 1 is partially compatible with existing ratings and partially
verifiable
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Application of Methods on Parallel HEV
• Engine appears to be at rated power (from data)
• Method 1 and Method 2 are similar in value (small battery assist)
• As expected, Method 3 provides much a lower power rating than
the other two.
Axlemeas = 125 kW
Engine assumed to be
at rated power here
Elecmeas = 35 kW
Current OEM Catalog Ratings
Engine: 123.7 kW
Motor: 30 kW (mechanical)
Total: 153.7 kW
Method (1)
123.7 + 35 = 158.7 kW
(engine rating + measured battery power)
“Method (2)
123.7 + 29 = 152.7 kW
Motorest = 29 kW
(engine rating + reported motor power)
Method (3)
Total: 125 kW
Time
(measured axle kW)
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Application of Methods on Series HEV
•
•
•
•
Engine appears to be at rated power (from data)
Method 2: Total power = Motor Power (CAN bus RPM and torque)
Method 1 and Method 2 are 23 kW different
Method 2 and Method 3 are different by only 8 kW
Motorest = 124 kW
Axlemeas = 116 kW
Battmeas = 42 kW
Current OEM Catalog Ratings
Engine: 105.1 kW
Motor: 123.8 kW
Total: 123.8 kW
Method (1)
105.1 + 42 = 147.1 kW
(rated engine kW + measured battery kW)
Point at expected rated Eng kW
- Peak fuel, peak RPM
Method (2)
Series HEV output = only Motor kW
Motor output: 124 kW
(from CAN bus)
Method (3)
Total: 116 kW
(measured axle power)
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Application of Methods on (another) Series HEV
• Engine power taken from CAN bus, motor power at rated power
• Method 1 has very high result, 30 kW higher than Method 2
Current OEM Catalog Ratings
Engine: 63 kW
Motor: 111 kW
Total: 111 kW
105 kW
Method (1)
61 + 80 = 141 kW
(CAN bus engine kW + measured battery kW)
80 kW
61 kW
Method (2)
Series HEV output = only Motor kW
Rated motor = 111 kW
Method (3)
Total: 105 kW
(measured axle power)
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Final Issue: Processing Results
•
•
•
•
•
All methods will require some filter applied to results
Data signals must be filtered for robust result (avoid transient spikes or signal noise)
Filter duration defines the duration period of peak power
We must decide duration of filter size recognizing this choice is arbitrary but uniform
Other viable methods besides window filter?
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J2908 Summary / Conclusions
• Test procedures should be flexible to achieve
highest and most representative peak power
• Hybrids are transient in nature, definition of
power is linked to duration (filter size)
• Must resolve Key Issue:
– Should hybrid rating be molded to fit current
rating?
– Should all vehicle power ratings switch basis to
wheel/axle power
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