Drive cycle consumption
To measure the consumption, we are going to drive the car until the battery is empty and see how far it came. With this kind of competition, the amount of power versus distance is measured. It turns out that the slower you drive, the less the friction and windage losses are, leading to a lower consumption and thus a larger distance. Let us put it to the test.
Connect all components and add a scope to measure the vehicle speed.
First we assume a constant speed of 80[km/h]. We can drive nearly 200[km], before the battery SoC drops below 10% and cannot deliver any power any more because of the low voltage.
When we increase the speed to 90km/h, we have more windage and driving mechanical losses. The total distanceis now reduced to 170[km].
Driveing the maximum speed of 120[km] cost even more energy, as driving losses increase. Especially the driving force to overcome the wind on the front of the car, increases the overall power required to maintain driving at 120[km/h] and reduce the total range the car can drive. The car can only drive a 125 kilometers before the battery is empty.
Driving at constant speed is nearly impossible and a more realistic consumption can be estimated when comparing consumption against a drive cycle.
If we drive the car according to the NEDC drive cycle, we can simulate the amount of energy required when start-stop and regeneration becomes an issue.
Electric power consumption
Parameters
To perform these kind of consumption studies, a number of key parameters are required to get a basic insight of the electrical consumption. For the battery, most important are the battery power density in [kwh], its internal resistance [Ω] to simulate the losses(Default is 10mΩ). The car mass[kg] and frontal area [m2] are key parameters. All other parameters can be replaced by their default values, as their influence is below 5 to 10%.
Parameters Car and LiIon Battery
LiIonModule -
Connection Diagram:
| PLUS | ||
|
| ATHERMAL | |
| SOC | ||
| MINUS |
| Connections(79) | Position | Remark |
| SOC | Right | |
| PLUS | Top | |
| MINUS | Bottom | |
| ATHERMAL | Right |
| Parameters(19) | Default | Remark |
| Ah | 1 | Maximuj charge, called the Ampere-Hours of the battery |
| Voc100 | 3.6 | Voltage for 100% Soc |
| Voc95 | 3.372 | Voltage for 95% Soc |
| Voc60 | 3.312 | Voltage for 60% Soc |
| Voc40 | 3.288 | Voltage for 40% Soc |
| Voc10 | 2.874 | Voltage for 10% Soc |
| Tslow[s] | 180 | Slow time constnt related to the mass transport (diffusion) |
| ReferenceTemperature[C] | 25 | |
| Fast Time constant | 5 | Fast time constant related to the electric double layer SEI |
| SoC[time=0] | 100 | Initial State of charge |
| Rtotal[Ohm] | 125m | Total series resistance |
| Nseries | 1 | |
| Nparallel | 1 | |
| Lseries | 1uH | |
| TemperaturefudgeFactor2 | -5.7 | |
| TemperatureFudgeFactor1 | 500 | |
| Rthermal | 1e-3 | |
| Mass[Kg] | 1e6 | |
| SpecificHeat[J/Kg/K] | 1 |
| Function | ||
| Status | Standard | |
| Select from | Components\Library\Electric\Battery | |