Simscape thermal mass discrete model

Hi, I'm trying to create a model of a lithium battery that will run with a discrete solver. The last hurdle I've come across seems to be the Thermal Mass block which I am using to simulate heat loss in the battery. The Thermal Mass block contains this line : Q == mass * sp_heat * T.der;. The T.der part seems to be what is preventing my model from running with a discrete solver as it is a continuous time derivative function. I have the following questions:

• Is there a discrete alternative to the Thermal Mass block?
• If not, is it possible to replace T.der by a discrete counterpart?
• Is is possible to incorporate the Discrete Differentiator block from the Simulink library into the Thermal Mass source code?

Thanks in advance.

Answer 1

[Javier Gazzarri]

Dear Lalumet,

A discrete solver can be used if you set up "Use Local Solver" in the Simscape Solver configuration block. Please see the simple example attached.

Please let me know if this solves your problem.

Best regards,

Javier

[Duilio Graciano Diniz Costa]

Hi Javier Gazzarri,

Could you please attach the example? I think that have the same problem.

thank you very much,

Duilio