DE, error, This function cannot be used here

[ptc-4975800]

I cannot solve a nonlinear DE, the Odesolve gives the error "This function cannot be used here" (Mathcad 15 M020), please help!

[ptc-4975800]

Mathcad file with english symbols.

[AndyWesterman · Accepted solution]

Hello Ivanov,

Looking at your worksheet , I think that the problem comes from the definition of mu.

The DE initial condition i.0(0)=0 means that the diferential equation has to calculate the L.0 value for i=0 & the mu function in this case will return NaN so the calculation must fail.

For a magnetic material I would not expect the mu value to increase asympototically to infinity but rather plateau at a value determined by the material & core parameters.

Hope this helps

Regards

Andy

[ptc-4975800]

Thank you very much!

Yes, this is a mistake comes from the definition of mu. I made a correction.