Hey everybody,

hope you can help me with this problem. I have a programm code about an electric drive and some physical properties. I want to calculate some values. But every compiler says, that the code is singular. But I don't understand why, cause I have 4 unknowns and 4 equations...

maybe you can give me a hint.
Here's the code:

model E_Motor

        import Modelica.SIunits;
    input SIunits.Frequency freqHzIst(start=50);
    input SIunits.Voltage UIst(start=400);
    input SIunits.Current IMax(start=5);
    parameter SIunits.Inertia JAntrieb(start=30);
    parameter Real i(start=5);
    parameter Integer p(start=2);
    parameter SIunits.Frequency freqHzNenn(start=50);
    parameter SIunits.AngularVelocity nNenn(start=1430);
    parameter SIunits.Inertia JRot(start=0.003);
    parameter Real pi=2*Modelica.Math.asin(1.0);
    parameter SIunits.AngularVelocity nIst;
    parameter SIunits.AngularVelocity w;
    parameter SIunits.KineticEnergy EKinMax;
    parameter SIunits.Power PMax;

equation
        nIst=((freqHzIst/p)*(nNenn/(freqHzNenn/p)))/i;
        w=2*pi*nIst;
        EKinMax=0.5*(JAntrieb+JRot)*w^2;
        PMax=UIst*IMax;

end E_Motor;

thank you very much in advanced!