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check error: "The problem is structurally singular."

check error: "The problem is structurally singular."

"the model  is structurally singular" is the alarm message during the check. What is the problem?

Edited by: claudio34 - Aug-29-15 20:05:44
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Re: check error: "The problem is structurally singular."

Did you attached your model? Or can you give some more information about what you are doing? Otherwise it is hard to say what the issue is in your case.

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Re: check error: "The problem is structurally singular."

this model works good, in this model the principal parameters  is a matrix [6,1], every array [ : , 1 ]  (one column) is ok:
"model AdvancedStackCycling2
  extends Modelica.Icons.Example;
  parameter CellRecords.LinearDynamicImpedance.LinearDynamicImpedanceParameters cellParameters2[:, :] = {{CellRecords.LinearDynamicImpedance.Test1Parameters()}, {CellRecords.LinearDynamicImpedance.Test1Parameters()}, {CellRecords.LinearDynamicImpedance.Test1Parameters()}, {CellRecords.LinearDynamicImpedance.Test1Parameters()}, {CellRecords.LinearDynamicImpedance.Test1Parameters()}, {CellRecords.LinearDynamicImpedance.Test1Parameters()}}  ...."


In this model simulation don't start, check is ok but simulation no. In this model the principal parameters  is a array [3,2]:
"model AdvancedStackCycling2
  extends Modelica.Icons.Example;
  parameter CellRecords.LinearDynamicImpedance.LinearDynamicImpedanceParameters cellParameters2[:, :] = { CellRecords.LinearDynamicImpedance.Test1Parameters(), CellRecords.LinearDynamicImpedance.Test1Parameters()}, {CellRecords.LinearDynamicImpedance.Test1Parameters(), CellRecords.LinearDynamicImpedance.Test1Parameters()}, {CellRecords.LinearDynamicImpedance.Test1Parameters(), {CellRecords.LinearDynamicImpedance.Test1Parameters()} }  ...."

If the array column is difference to 1 (array [ 7, 2] forx example)   simulation don't start. Every array with one column is ok, with the others array model pass the check but simulation don't start

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Re: check error: "The problem is structurally singular."


error:
The problem is structurally singular.
It has 1220 scalar unknowns and 1220 scalar equations.
The Real part has 1216 unknowns and 1216 equations.
The Integer part has 4 unknowns and 4 equations.
The Boolean part has 0 unknowns and 0 equations.
The String part has 0 unknowns and 0 equations.

Attempting to further localize singularity.

The model component fixedTemperature[1, 1] has the same number of unknowns and equations.

The model component fixedTemperature[1, 2] has the same number of unknowns and equations.

The model component fixedTemperature[2, 1] has the same number of unknowns and equations.

The model component fixedTemperature[2, 2] has the same number of unknowns and equations.

The model component cell[1, 1] has the same number of unknowns and equations.

The model component cell[1, 2] has the same number of unknowns and equations.

The model component cell[2, 1] has the same number of unknowns and equations.

The model component cell[2, 2] has the same number of unknowns and equations.

Singularity of Modelica_EnergyStorages.Batteries.Stacks.Basic.LinearDynamicImpedanceMatrix is at the top level.

The model Modelica_EnergyStorages.Batteries.Stacks.Basic.LinearDynamicImpedanceMatrix is structurally singular,
when assuming the most generic outside couplings to all the flow variables of its connectors.

The problem is structurally singular for the element type Real.
The number of scalar Real unknown elements are 1216.
The number of scalar Real equation elements are 1216.

The model includes the following hints:
An electrical current cannot be uniquely calculated.
The reason could be that
- a ground object is missing (Modelica.Electrical.Analog.Basic.Ground)
to define the zero potential of the electrical circuit, or
- a connector of an electrical component is not connected.

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Re: check error: "The problem is structurally singular."

Hi, I wonder did you manage to solve the problem now, as i met exactly the same issue. I'm also doing the electrical system. If you solved this problem, can you share with me how to solve it?

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Re: check error: "The problem is structurally singular."

no, it's a problem of openmodelica solver, with dymola the battery library works good

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Re: check error: "The problem is structurally singular."

I am a beginner in modelica and using Dymola. This is a common error that I receive at most "The problem is structurally singular for the element type Real".

Can anybody explain what to check in the model when this error is issued?

Regards.

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Re: check error: "The problem is structurally singular."

Hi
Maybe you have closed kinematic chain?

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Re: check error: "The problem is structurally singular."

For people who might see this with the same problem: :

http://www.claytex.com/blog/getting-sta … ola-model/

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