"First solve for initial conditions failed to converge." Thermal model

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I struggle with my model failing to solve for my set initial conditions. I have built a thermal model for an electric actuator using thermal mass and convection blocks from simcape. However, I get a warning that there are conflicts between the model temperature constraint and the blocks target.
I am trying to set a starting temperature for the whole system at 20 degC, but in the following branch and mass codes I am not able to overrun the block's initial target. I have set "override" and the priority at high in the convection blocks parameters in simulink.
Example warning:
Branch.ssc with the first reffered equation:
component (Hidden=true) branch
% Thermal Branch
% This base component defines a branch with two ports in a thermal network.
% It also defines the temperature change and the heat flow rate through
% the branch.
% Copyright 2005-2016 The MathWorks, Inc.
nodes
A = foundation.thermal.thermal; % A:left
B = foundation.thermal.thermal; % B:right
end
variables (Conversion=relative)
T = {0, 'degC'}; % Temperature difference
end
variables
Q = {0, 'W'}; % Heat flow rate
end
branches
Q : A.Q -> B.Q;
end
equations
T == A.T - B.T;
end
end

Answers (1)

Martin
Martin on 20 Jul 2020
Hello Kotryna,
The temperature on those blocks is a difference, not absolute. Also focus on specifying the differential variables, otherwise the system may become overspecified.
Martin

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