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JRCSTU / CO2MPAS-TA

EU's Type-Approving vehicle simulator predicting NEDC CO2 emissions from WLTP
https://co2mpas.readthedocs.io/
European Union Public License 1.1
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Sign of alternator current #35

Open Steinbachson opened 5 years ago

Steinbachson commented 5 years ago

CO2MPAS declares the INCA Export data would have the wrong sign, so you have to multiplicate with *(-1). Does anybody know why CO2MPAS cannot work with the original INCA export data or knows something about the logic?

gfon commented 5 years ago

@Steinbachson, Seasons Greetings. We are not sure we understand fully the question but we can comment on the following. CO2MPAS input does not follow a specific standard for testing-hardware/software . So it is very likely that incompatibilities exist with different commercial platforms. The sign of the currents follows the following convention, current entering the battery should be positive and current exiting the battery should be negative. In cases of current measurements done outside the CAN, the amperometer positioning on the cable can affect the sign. Hence we advise always to double check the input data prior to running co2mpas in order to make sure that the correct current signs have been applied. The same convention applies to the alternator current (negative sign for current supplied to the vehicle by the alternator). You may find some additional information in the model description presentations here.

CC'd: @vinci1it2000 @dimitriskomnos