There isn't such a clear interpretation of "inductance" for nonlinear systems, because inductance is a proportionality constant between current and flux linkage that is supposed to be independent of current. If you have a nonlinear system, you can get an inductance-like proportionality constant between the instantaneous current and the instantaneous flux via the A.J integral divided by i^2 (i.e. same procedure as with a linear system); however, this value is not related to energy in a simple way. Alternatively, if you have an AC system, it is sometimes useful to derive an "inductance" based on the average stored energy over a cycle that is a function of the current amplitude. In this case, you can pick the "inductance" so that the energy obeys linear-looking formulas for computing energy; however, there will be errors in the instantaneous flux density.
Hello everybody,
I would like to calculate the d and q inductance of a synchronous machine. The relation Ld*Id^2 = Energy (for a d axis field applied) is correct only for linear case. But for saturated case, I'm a little confused ! Any help would be very appreciated.
Best regards
Tsarafidy.
Dave. -- David Meeker email: dmeeker@xxxxxxxx www: http://femm.berlios.de/dmeeker