1.3.1. BMS Reference Design Car Model
The Urban Dynamometer Driving Schedule (UDDS), the Highway Fuel Economy Test (HWFET) and the Federal Test Procedure (FTP) are defined by the U.S. Environmental Protection Agency. The New European Driving Cycle (NEDC), the Extra-Urban Driving Cycle (EUDC) and the Economic Commission for Europe urban driving cycle (ECE R15) are maintained by the United Nations Economic Commission for Europe (UNECE). The Common Artemis Driving Cycles consists of the Urban cycle (ArtUrban), the Rural road cycle (ArtRoad) and the Motorway cycles (ArtMw130 and ArtMw150, with a maximum speed of 130 and 150 km/h, respectively). The Worldwide harmonized Light vehicles Test Procedures (WLTP) Class 3 is developed the following the guidelines of UNECE World Forum for Harmonization of Vehicle Regulations. The various cycles differ in the average speed and electric power required from the traction battery.
Driving Cycle | Duration (min) | Distance (km) | Average speed (km/h) |
---|---|---|---|
UDDS | 23 | 12.0 | 31.5 |
HWFET | 13 | 16.5 | 77.5 |
FTP | 31 | 17.8 | 34.1 |
EUDC | 7 | 6.5 | 58.6 |
NEDC | 20 | 8.3 | 25.4 |
ECE R15 | 3 | 0.9 | 16.5 |
WLTP class 3 | 30 | 23.2 | 46.5 |
ArtUrban | 17 | 4.9 | 17.6 |
ArtRoad | 18 | 17.3 | 57.4 |
ArtMw130 | 18 | 28.7 | 96.8 |
ArtMw150 | 18 | 29.5 | 99.5 |
where:
- M is the kerb weight
- S is the frontal area
- C X is the drag coefficient
- R is the rolling resistance
- ρ air is the air density
- g is the gravity acceleration
- v is the speed.
You obtain the electric power P e from P m where:
- η wheel is the efficiency from the battery to the wheels
- η reg is the efficiency in the opposite direction, i.e., during the regenerative breaking.
To obtain the battery current, divide the electric power by the sum of the cell voltages calculated by the battery model.