Currently, paragraph 2.2 of Appendix 2 to Annex 8 reads:
2.2
The correction coefficients shall be determined from a set of nCS CS type 1 tests performed
by the manufacturer. This set shall contain at least one test with ∆EREESS,CS ≤ 0 and at least
one with ∆EREESS,CS > 0. ∆EREESS,CS,n is the sum of electric energy changes of all REESS of
test n calculated according to paragraph 1.1 of this Annex.
If the latter condition cannot be realised on the test cycle, the responsible authority shall
evaluate the statistical significance of the extrapolation that is necessary to determine the
corrected CO2 mass emission and fuel consumption at ∆EREESS,CS = 0.
New proposal by T&E:
2.2
The correction coefficients shall be determined from a set of nCS CS type 1 tests performed
by the manufacturer. This set shall contain at least one test with ∆EREESS,CS ≤ 0 and at least
one with ∆EREESS,CS > 0. ∆EREESS,CS,n is the sum of electric energy changes of all REESS of
test n calculated according to paragraph 1.1 of this Annex.
In the unlikely event that it is not possible to achieve a set of type 1 tests with at least one
test with ∆EREESS,CS ≤ 0 and at least one with ∆EREESS,CS > 0, the manufacturer may
request the state of charge of the REESS prior to the test to be set according to the
manufacturer’s recommendation. This practice shall only be used for the purpose of
achieving a type 1 test with opposite sign of the ∆EREESS,CS and with approval of the type
approval authority.
Rationale:
First of all, it is very unlikely that this would happen. Since the vehicle is tested in charge sustaining
mode there would always come a cycle where the sign of ∆EREESS,CS would reverse (otherwise the
battery would either be overloaded or depleted completely). Therefore, the manufacturer should be
able to give a sound explanation to the type approval authority what the reason is for this
exceptional behaviour.
Secondly, the correlation coefficient is better defined by an interpolation between positive and
negative ∆EREESS,CS values, rather than an extrapolation from only positive or only negative values.
Therefore T&E recommends to apply this SOC manipulation to force a ∆EREESS,CS with opposite sign.
The text of this paragraph was chosen similar to par. 2.1.4 of Appendix 4
Currently, paragraph 2.1.4 of Appendix 4 reads:
Alternatively, at the request of the manufacturer, the state of charge of the REESS for the chargesustaining test can be set according to the manufacturer’s recommendation in order to achieve a
charge balance neutral charge-sustaining test.
In such a case, an additional ICE preconditioning procedure as described in paragraph 1.2.6. of Annex
6, may be applied.
It is not clear if this should read “may be applied” or “shall be applied”. T&E would like to know what
the intention is of this requirement, and proposes to discuss this during the next EV group meeting.