[Getdp] frequency slip

[Christian Geikowsky]

Dr. Johan Gyselinck:

Thank you for his answer...

After your remarks I am born to some questions. Prior to the model vxB that I sent it, I implemented it that you recommend me now. Some of the models previous, I explain them to him below:

Model 1: 

Function {

...

slip=0.1;

Frec=50*slip; 

...

}



Constraint {

...

{ Name Jo; Type Assign;

Case {

{ Region FaseAin; Value Corr_FaseAi[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseA}; }

{ Region FaseCout; Value Corr_FaseCo[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseC}; }

{ Region FaseBin; Value Corr_FaseBi[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseB}; }

{ Region FaseAout; Value Corr_FaseAo[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseA}; }

{ Region FaseCin; Value Corr_FaseCi[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseC}; }

{ Region FaseBout; Value Corr_FaseBo[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseB}; }

}

}

}



Formulation {

{ Name Magnetismo; Type FemEquation;



...

Equation {

Galerkin { [ nu[]*Dof{Curl a}, {Curl a}]; In Todo;

Jacobian JacobVol; Integration Integra; }



Galerkin { [ - Dof{js} , {a} ]; In ConducEst;

Jacobian JacobVol; Integration Integra; }



Galerkin { DtDof [ sigma[] * Dof{a} , {a} ]; In Rotor;

Jacobian JacobVol; Integration Integra; }

Galerkin { [ sigma[] * Dof{e} , {a} ]; In Rotor;

Jacobian JacobVol; Integration Integra; }



Galerkin { DtDof [ sigma[] * Dof{a} , {e} ]; In Rotor;

Jacobian JacobVol; Integration Integra; }

Galerkin { [ sigma[] * Dof{e} , {e} ]; In Rotor;

Jacobian JacobVol; Integration Integra; }



GlobalTerm { [ Dof{I} , {U} ]; In ConducRot; }

}

}

}



Resolution {

{ Name Magnetismo;

System {

{ Name Sys_Mag; NameOfFormulation Magnetismo; 

Type ComplexValue; Frequency Frec; } 

}

Operation {

Generate[Sys_Mag]; Solve[Sys_Mag]; SaveSolution[Sys_Mag];

}

}

}



 

Model 2:

Function {

...

slip=0.1;

Frec=50; 

...

}



Constraint {

...

{ Name Jo; Type Assign;

Case {

{ Region FaseAin; Value Corr_FaseAi[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseA}; }

{ Region FaseCout; Value Corr_FaseCo[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseC}; }

{ Region FaseBin; Value Corr_FaseBi[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseB}; }

{ Region FaseAout; Value Corr_FaseAo[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseA}; }

{ Region FaseCin; Value Corr_FaseCi[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseC}; }

{ Region FaseBout; Value Corr_FaseBo[]/SecDev[]; TimeFunction F_Cos_wt_p[]{w,phaseB}; }

}

}

}



Formulation {

{ Name Magnetismo; Type FemEquation;



...

Equation {

Galerkin { [ nu[]*Dof{Curl a}, {Curl a}]; In Todo;

Jacobian JacobVol; Integration Integra; }



Galerkin { [ - Dof{js} , {a} ]; In ConducEst;

Jacobian JacobVol; Integration Integra; }



Galerkin { DtDof [ sigma[]* slip* Dof{a} , {a} ]; In Rotor;

Jacobian JacobVol; Integration Integra; }

Galerkin { [ sigma[] * Dof{e} , {a} ]; In Rotor;

Jacobian JacobVol; Integration Integra; }



Galerkin { DtDof [ sigma[]* slip* Dof{a} , {e} ]; In Rotor;

Jacobian JacobVol; Integration Integra; }

Galerkin { [ sigma[] * Dof{e} , {e} ]; In Rotor;

Jacobian JacobVol; Integration Integra; }



GlobalTerm { [ Dof{I} , {U} ]; In ConducRot; }

}

}

}



Resolution {

{ Name Magnetismo;

System {

{ Name Sys_Mag; NameOfFormulation Magnetismo; 

Type ComplexValue; Frequency Frec; } 

}

Operation {

Generate[Sys_Mag]; Solve[Sys_Mag]; SaveSolution[Sys_Mag];

}

}

}

 

 

In the first model, the simulation frequency is the slip frequency, for it that the current density in the rotor corresponds to that frequency. The current densities in the core and in the rotor bars are examined in this case.

In the second model, he is the frequency of the source of 50 [Hz]. To multiply dA/dt for the slip, the relative velocity of the rotor with the stator is considered.

On both instances the current densities are equal, included the current densities of the stator core are it.



I suppose that the magnitudes of the current density of the stator core must be different, the first to frequency of slip and the seconds to frequency of the source.

What error I am committing?

In your model. How considers the current density of the nucleus of the stator at 50 [Hz]?

Johan Gyselinck wrote:

> The simplest way to model an induction motor with the FEM taking into 

> account the slip and induced currents in the rotor cage, is in the 

> frequency domain (supply frequency) with a FE model without movement. 

> The movement is taken into account by multiplying the conductivity of 

> the rotor bars by the slip value. This agrees with the division of the 

> rotor resistance by the slip in the per phase equivalent scheme.



In the phase equivalent scheme, the frequency of the source is 50 [Hz], so that I understand in their own model to multiply the conductivity of the rotor bars by the slip is optional to modify the frequency of the source and no both at the same time.

 

The objective of this research is to determine the losses of the stator and rotor core for different slips.

 

 

Waiting for a quick response and thank you beforehand


Greeting


Christian Geikowsky R

Universidad Técnica Federico Santa María

Departamento de Electricidad

Programa de Magíster en Ciencias de la Ingeniería Eléctrica.

Valparaíso

Chile.

email: christiangeikowsky at yahoo.es - otulp at 123mail.cl


		
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