Comment Log Display

US Hybrid is pleased to provide the following
recommendation/comments on the proposed ZEV certification.
The California standards and test procedures for new 2021 and
subsequent model heavy-duty zero-emission powertrains requires
better-quantified definitions in support of test procedures, so the
consumer, powertrain technology provider, OEM, and the dealer have
uniform understanding of the ratings. 
Following is the recommendation to be included in the test
procedures for the zero emission MD/HD vehicles:
Table 1. Fuel Cell Engine Energy Efficiency Determination.
Item	Definition	Requirements  
1	FC Rated Power	The FC engine must provide the manufacturer
specified rated power and energy efficiency for at least 1 hour as
continuous power at the vehicle or equivalent test configuration
with an ambient temperature of >35C and specified rated cooling
system (>60C). Rated power is to be provided at rated voltage and
the power rating at the end of 1 hour, and the test must meet the
manufacturer specified name plate. This is the Beginning-Of-Life
(BOL) test power rating. 
2	FC Maximum Power	The FC engine must provide the manufacturer
specified max power for at least 5 minutes (after being subjected
to 15 minutes of continuous rated power) at the vehicle, or
equivalent test configuration with ambient temperature of >35C and
specified rated cooling system (>60C).
3	FC End-of-Life	FC engine manufacturer must specify the
End-of-Life (EOL) definition for the fuel cell engine as % of rated
power and maximum power at the end of 1 hour of testing/operation
for continuous power and 5 minutes for max power. Typically 70%.
4	FC Run Decay	FC engine manufacturer must specify the End-of-Day
(EOD) power rating decay based on 8 hours of operation.  
5	FC Engine Rated Energy Efficiency 	FC engine manufacturer must
specify the FC engine energy efficiency kWhr/kg-H2, NET after the
FC engine with all BOP included and NET after the dc-dc converter
output to the vehicle HV system, at the end of 1 hour of operation
at rated power and end of the 5 minute operation at the maximum
power. 
6	FC Engine Energy Efficiency Map	FC engine manufacturer must
provide the FC engine energy efficiency over the FC engine
operation from 10% to 100% of power rating at rated voltage
(kWhr/kg-H2 NET) after the FC engine with all BOP included and
kWhr/kg-H2 NET after the dc-dc converter output to the vehicle HV
system. FC engine shall operate for >30 minutes at rated power
before reducing power at 10% step and taking energy efficiency
measurement at the end of this test to measure energy efficiency
after 2 minutes of operation with the maximum power.
Table 2. Energy Storage System Rated and Peak Power Testing.  
Item	Definition	Requirements  
1	Battery Energy Storage Rated Power	The battery energy storage
system must provide the rated power for at least 1 hour as
continuous power at the vehicle or equivalent test configuration
with ambient temperature of >35C and specified rated cooling system
(>60C). 
2	Battery Energy Storage Max Power	The battery energy storage
system must provide the manufacturer specified max power for at
least 5 minutes (after being subjected to 15 minutes of continuous
rated power) at the vehicle or equivalent test configuration with
ambient temperature of >35C and specified rated cooling system
(>60C).
3	Battery Energy Storage End-of-Life	Battery system manufacturer
must specify the End-of-Life (EOL) definition for the battery as %
of rated power and energy at the end of 1 hour of testing/operation
for continuous power as well as after 5 minutes at maximum power at
EOL.
4	Battery System Energy Efficiency Map	Battery manufacturer must
provide the battery system round trip energy efficiency over the FC
engine operation from 10% to 100% of power rating.  

Table 3. Powertrain System Rated and Peak Power Testing.  
Item	Definition	Requirements  
1	Powertrain Rated Power	Powertrain system must provide the rated
power for at least 1 hour as continuous power at the vehicle or
equivalent test configuration with ambient temperature of >35C and
specified rated cooling system (>60C). 
2	Powertrain Max Power	Powertrain system must provide the
manufacturer specified max power for at least 5 minutes (after
being subjected to 15 minutes of continuous rated power) at the
vehicle, or equivalent test configuration with ambient temperature
of >35C and specified rated cooling system (>60C).
3	Powertrain Energy-Eff Map	Powertrain manufacturer must provide
the powertrain system energy efficiency over the operation from 10%
to 100% of power rating at 25%, 50%, 75% and max speed.  

Table 4. Charger System Rated and Peak Power Testing.  
Item	Definition	Requirements  
1	Charger Rated Power	Charger system must provide the rated power
for at least 1 hour as continuous power at the vehicle or
equivalent test configuration with ambient temperature of >35C and
specified rated cooling system (>60C). 
2	Charger Max Power	Charger system must provide the manufacturer
specified max power for at least 30 minutes (after being subjected
to 15 minutes of continuous rated power) at the vehicle, or
equivalent test configuration with ambient temperature of >35C and
specified rated cooling system (>60C).
3	Charger Energy Efficiency Map	Charger manufacturer must provide
the charger system energy efficiency (AC-in/DC-out to battery) over
the operation at 10%, 25%, 50%, 75% and 100% of max power rating at
base voltage +/-20%.