Week 5 Battery characteristics using drive cycle

Use of Driving cycle:

Driving cycle are generally use to to simulate the actual driving pattern in test lab. Driving cycle are derived once and it is fed to vehicle dynamometer to simulate the driving pattern. One of the standard driving cycle is UDDS. The EPA Urban Dynamometer Driving Schedule (UDDS) is the city test and represents city driving conditions. It is used for light duty vehicle testing.

To simulate the above driving cycle in Matlab, this data need to fed into signal builder. But, the limitation of the signal builder is that, it accept only current profile. Thus, the Vehicle speed vs time data need to convert to current vs time data.

To simulate the battery behaviour in matlab, we need signal builder to input the currrent profile, controlled current source to provide input to the battery and to get the output scope is required. thus the matlab block is as followes.

Signal Builder: The driving cycle input is provided through the block .To input the driving cycle, first it is required to convert the speed vs Time data to current Vs Time .

Controlled Current Source: The Controlled Current Source block converts the input signal into an equivalent current source. The generated current is driven by the input signal of the block.

The simulation is performed with following battery configuration.

Result:

From the above result it is observed that the SOC of the battery is decreased to 96% from fully charged condition and voltage of the battery decreases to 7.8 V. Below fig. is showing the exaggerated view of the result. It is observed that, during deceleration of the vehicle, there is minor but increase in SOC of the battery. This indicating the charging of the battery.