Singular matrix when running Load Flow on Simulink Powergui

When running a Load Flow from Powergui on simulink I am getting this warning, which makes all the results of the load flow to be NaN.

I have realized this only happens when, in the Load Flow Parameters tab, the base power is set to be a variable instead of a numerical value. i.e: when Base Power = 100e6 it works fine, however it is when I set Base Power = S_base (which is a variable I set on a matlab script I run before running the load flow) when I get this error.

%  Warning: Matrix is singular, close to singular or badly scaled. Results may be inaccurate. RCOND = NaN.  
%     > In LoadFlowTool 
%     In LoadFlowTool 
%     In LoadFlowTool 
%     In power_loadflow (line 131) 
%     In runpf (line 2) 
%     In Model (line 53) 

Answer 1

[Nadia Shaik]

Hi Sergi,

The warning message you are getting is likely indicating that there is a problem with the value of the base power you are using as a variable (i.e., S_base) in the Load Flow Parameters tab. This could be because the value of "S_base" is not being properly defined or calculated before the Load Flow is Run.

To ensure that "S_base" is properly defined and calculated, check the following:

1. Make sure that "S_base" is defined in your MATLAB Script before it is used in the Load Flow Parameters tab. You can do this by verifying that the script is being run successfully without any errors.
2. Try printing the value of "S_base" to the MATLAB Command Window before running the Load Flow to confirm that it is being properly calculated.
3. Verify that the value of "S_base" is not NaN or Inf. If "S_base" is NaN or Inf, this could cause the Load Flow to return NaN results when passed as one of the arguments to the backslash (\) or forward slash (/) operators, which are commonly used to solve systems of linear equations.
4. Check that the units of "S_base" are consistent with the units used in the Load Flow Parameters tab.

I hope the above information resolves your query.