How do I switch on and off my voltage source to charge batteryes based off of my current state of charge?

I'm trying to implement a closed-loop system that uses a state of charge percentage which turns on/off a DC voltage source for charging batteries as seen in my attached simulink project.

What blocks or set ups would I use that would disconnect the batteries in series when the SOC is <20% and then connect a DC voltage source to charge the batteries until they reach 80%, where then the system would switch back from the voltage source and the batteries would resume powering the DC system.

Basically the blocks would be set up such that:

if state of charge from batteries in series is less than 20%, then disconnect the batteries from what they're powering and connect them to a DC voltage source to charge them until they reach 80% where then the switch would go back to before and the batteries would return to powering a system until they reach 20% again.

Answer 1

[madhan ravi]

I don"T have Simscape License. But the logic can be implemented.

Feed the SOC signal to the switch Switch provide the threshold, by using this switch you need to use it for load and the voltage source. But using PS Switch you can close and open load and voltage source by giving the appropriate threshold.

Note make sure to convert the SOC Simulink Signal to Physical Signal using Simulink - PS Converter block.

[Jonas]

Thank you for your response, I'll try to implement your answer and notify you my results

[Jonas]

I wasn't able to implement it. I'm still very lost. this is what I have now.

[madhan ravi]

Please provide a picture since I don’t have the license.

[Jonas]

[madhan ravi]

Doesn"t your current implementation work? It seems to be ok, not sure what"s happening within the MATLAB Funnction block.

[Jonas]

My mistake I should have included the block too. What happens is if the code runs for too long, the values of the SOC run out of control. Here is the code inside the block.

[madhan ravi]

Could you be more descriptive ? When you mean run out of control? Do you mean it exceeds the values?

And only include the code from

 if(SOC < .2) 
   …

   SW = 1; 

 end

Remove all the other lines than the ones I mentioned above

[Jonas]

Yes that's right, either it exceed 1 and goes on forever, or it drops past 0 and goes on forever in the negatives

[madhan ravi]

Throw in a saturation block after "For Each Subsytem" with lower limit 0 and upper limit 1. By the way, the SOC shouldn"t exceed 0 and 1. There might be some calculation error within the "For Each Subsytem" the way it"s being calculated.

Just realised, the way you have implemented the switches. The battery will only get discharged right? since the batterz is disconnected when the voltage source is connected to the load. Because the switches are not on at the same time.

This video might be helpful for you https://youtu.be/L_wVCoMyh5E?si=a4ZNqWVfWgsNEvGl

[Jonas]

Okay, I was able to implement what you recommended, everything appears to be in order, thank you!

[madhan ravi]

Wunderbar!