Physical consumption model for EVs
Note
This feature is currently in beta.
The physical consumption model estimates energy consumption on a given route and takes the following data into account:
- Physical properties of the vehicle
- Terrain properties
- Road network properties
Using this model enables the use of additional controls for energy consumption calculations, such as:
- Charging time
- Charge levels
- Charging stations
To use this model for energy consumption calculation, you must set the consumptionModel=physical option in the API request.
Parameters
EV vehicle properties
| Request parameter | Model parameter | Mandatory | Description |
|---|---|---|---|
ev[driveEfficiency] | $eta d$ | Yes | The proportion of the energy drawn from the battery that is used to do actual work to move the vehicle. Remaining part is lost due to inefficiencies mainly as heat. |
ev[recuperationEfficiency] | $eta r$ | Yes | The proportion of the energy gained when braking or going downhill that can be recuperated and restored as battery charge. |
ev[airDensity] | $ ho$ | No | Air density in $kg/m^3$. This has a default value of 1.225, which corresponds to air density for 15°C temperature at the sea level. |
ev[auxiliaryPowerConsumption] | $P$ | No | Power consumed by the vehicle's auxiliary systems, such as air conditioning and lights. Specified in watts. |
General vehicle properties
| Request parameter | Model parameter | Mandatory | Description |
|---|---|---|---|
vehicle[rollingResistanceCoefficient] | $C_{rr}$ | Yes | Describes the resistance that affects the vehicle's tire as it rolls over a surface. The main causes of this resistance are tire deformation, wing drag, and friction with the ground. The coefficient of rolling resistance is a numerical value indicating the severity of this factor. |
vehicle[airDragCoefficient] | $C_{d}$ | Yes | Describes the way the vehicle is expected to pass through the surrounding air. More streamlined vehicles are more aerodynamic and therefore have lower drag coefficient. |
vehicle[currentWeight] | $M$ | Yes | Current vehicle weight, including trailers and current load. Specified in kilograms. |
vehicle[frontalArea] | $A$ | No | Specifies the total cross-section area of the vehicle as viewed from the front. Specified in square meters. Must be set when width and height are not set. |
vehicle[width] | No | Vehicle width, specified in centimeters. | |
vehicle[height] | No | Vehicle height, specified in centimeters. |
Map data
The following values from the map data are used in calculating consumption:
| Parameter | Description |
|---|---|
| $L$ | Length of the segment, expressed in meters. |
| $Delta h$ | Elevation difference between the start and the end of the segment, expressed in meters. |
| $Delta v$ | Average speed difference between previous and next segment, expressed in meters per second. |
| $V$ | Average speed of a vehicle in a segment, expressed in meters per second. |
| $t$ | Time taken to travel the segment, expressed in seconds. |
Constant values
| Parameter | Value | Description |
|---|---|---|
| $g$ | 9.81 | Gravity on the surface of the Earth. |
Consumption calculation formula
The following table lists the intermediate components of the total used energy.
| Parameter | Unit | Description |
|---|---|---|
| $M_{air}$ | Nm | Moment needed to overcome the air resistance. |
| $M_{rol}$ | Nm | Moment needed to overcome the rolling resistance. |
| $E_{pot}$ | J | Energy gained or lost due to height difference. |
| $E_{kin}$ | J | Energy gained or lost due to speed difference. |
| $E_{aux}$ | Wh | Energy consumed by auxiliary systems. |
Nm and J are dimensionally equivalent in the sense that they have the same expression in SI base units, therefore moments can be summed up with energies. Resulting total energy needed to move the vehicle is in J and is divided by 3600 to convert into Wh.
In the final stage, drive or recuperation efficiency is accounted for and the auxiliary consumption is added. Drive or recuperation efficiency is applied per segment in the calculation depending on whether the consumption calculation result is a positive or a negative value.
Updated 10 days ago