Type mismatch for equation in SIMSCAPE

Error compiling Simscape network for model cardsimscape.

Caused by:

['cardsimscape/V12/int idt']: Type mismatch for equation. The left hand side of the equation is {[1x1 double], '1/s'} and the right hand side of the equation is {[1x1 double], 'A'}. In foundation.signal.linear.integrator (line 24)

x = [1x1 double]

I = {[1x1 double], 'A'}

Source code for PS-integrator (int idt) is below.

component integrator

% PS Integrator :0.75 :fixed

% This block performs continuous-time integration of the input Physical Signal.

% Copyright 2005-2018 The MathWorks, Inc.

inputs

I; % :left

end

outputs

O; % :right

end

parameters

x0 = { 0, 's' }; % Initial condition

end

variables(Access = private)

x = {value = x0.*ones(size(I)), priority = priority.high};

end

equations

x.der == I;

O == x;

end

annotations

x0 : UnitDropdown = common

end

end

Answer 1

[Sabin]

Hi,

The problem in this model is that a unit mismatch. The integrator is expecting a unitless physical signal while the Current sensor is providing a Current in Amperes. The solution here would be to use a PS-Gain with value 1 and unit 1/A between the Current Sensor and PS-Integrator. This will strip the unit and the model should work fine.

I hope this helps.

[Pulak Kumar Ray]

Thanks Sabin.