Unable to connect "DRIVE CYCLE SOURCE" block with "CONTROLLED CURRENT SOURCE" block.

Hi,

i want to connect the drive cycle source block with controlled current source block so as to monitor the effect of drive cycle in battery temperature over a period of time. But as i connect it, it is showing red highlighted signal with warning "unit mismatch :m/s to 1". Although i have changed the simulink to PS converter properties to "A" as i think it is for current(ampere,A) but after running the simulation, i am still getting same error in diagnostic tab. Please guide me through this. i have also shared the image for reference. Thank you.

Answer 1

[Xiangchun]

Hi Sudeep,

The Drive Cycle Source block provides velocity profile for standard drive cycles. We would need a vehicle model to convert velocity profile to a current profile. Vehicle model determines how much discharge current or regen charge current the battery pack needs to provide or accept. Once the current (in Amps) profile is created, we can connect that to a Controlled Current Source block to cycle a battery pack like what you have in the diagram.

To create a vehicle model, an easy way is to use Virtual Vehicle Composer: Configure, build, and analyze a virtual automotive vehicle - MATLAB (mathworks.com).

Best wishes,

Xiangchun

[SUDEEP SINGH RAWAT]

thanks for your response sir. my purpose is to see the effects of variable vehicle speed/acceleration on the temperature of the battery cells in a battery pack. When i use "battery" block and make battery pack from it, the drive cycle can be connected to it and the model works well( please see image attached) but when i create the battery pack using "battery builder app", i am unable to connect drive cycle to it. please respond.

Thank you.

[Xiangchun]

Hi Sudeep,

The Battery block, along with Controlled Current Source, used in the "battery pack with udds.jpg" attached above is from Specialized Power Systems in Simscape Electrical. These are Simulink blocks instead of Simscape blocks. They do not necessarily perform checks for units when Drive Cycle Source is connected to Controlled Current Source in Specialized Power Systems. On the other hand, the generated battery block from Battery Builder App is Simscape, and it works only with Simscape version of the Controlled Current Source block. Simscape detects a unit mismatch because Drive Cycle Source outputs vehicle speed (velocity) in m/s, km/h, or mph whereas Simscape Controlled Current Source expects a physical signal of current in Amp.

As mentioned in my previous comment, we do need a vehicle model to convert velocity profile to a current profile. Vehicle model determines how much discharge current or regen charge current the battery pack needs to provide or accept. Once the current (in Amps) profile is created, we can connect that to a Controlled Current Source block to cycle a battery pack like what you have in the diagram. To create a vehicle model, an easy way is to use Virtual Vehicle Composer: Configure, build, and analyze a virtual automotive vehicle - MATLAB (mathworks.com).

Best wishes,

Xiangchun

[SUDEEP SINGH RAWAT]

Thank you for your valuable feedback sir.

Regards,