-inf values for C rate

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Hemant Sriram

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Oct 14, 2021, 9:30:53 AM10/14/21
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Hi,

I am currently running a cruise mission profile for a system with values similar to the tut_solar_uav.py, but after changing a few values, I am getting "nan" or -inf values for Crate and battery Voltage for the electronic conditions plot. I understand that they are both dependent on the energy calculations of the battery. But, I am trying to figure out which input has a major effect on the same?

Is there a place where the power consumed is being calculated that updates the energy of the battery remaining? I have noticed by just changing the solar logic voltage, the graph values change drastically. I also read in an older post on the google group, that the solar logic module cannot be trusted as it isn't complete? is that still the case or has it been modified?

Hope to hear from you soon!
Hemant Sriram

ebot...@gmail.com

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Oct 15, 2021, 6:11:51 PM10/15/21
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Hi,
When you get -inf for voltage that means the battery's state of charge is negative (and usually highly negative). It physically doesn't make sense that a battery could be discharged past 0, but SUAVE allows it for optimization reasons. First thing to check is if you've set the battery energy at the first segment. Otherwise, the battery is too small for the mission/vehicle.

The solar logic voltage should be set to the same as the battery. The solar module can be trusted for solar aircraft. I'm not sure what you're referring to.

-Emilio

Hemant Sriram

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Oct 18, 2021, 6:16:16 AM10/18/21
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Hi Emilio,

Thank you for your answer. I am referring to this conversation here. I believe this has been resolved and updated in the latest 2.4.0 version?

Thank you for your help with the -inf C rate. trying to resolve that is still a major task as I am not really sure what value of battery voltage is needed for this particular mission. I tried a couple of different values but nothing worked.
 Hope I can figure it out and solve the issue soon.

Hemant
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