## Abstract:

This paper presents an efficient method of calculation concerning D-axis saturation in a synchronous

machine model when winding flux linkages are the state variables. A method is presented for calculation of a saturation indicator S based on a linear combination of the flux linkages in the D-axis windings. A method is then presented for developing a look-up curve F(S) which is dependent on the saturation indicator. The product of S times F(S) produces ψmd, the main mutual magnetizing flux linkage for the D-axis. The component of flux linkage due to leakage in each winding on the D-axis can be obtained by subtracting ψmd from the flux linkage of the particular winding. D-axis winding currents are subsequently

obtained by multiplying the components of winding flux linkages due to leakage by the pre-calculated inverse of the leakage inductance matrix.

*T. Maguire, R. Kuffel, In Proc. 7th International Conference on Modeling and Simulation of Electric Machines, Converters and Systems (Electrimacs 2002), Montreal Canada*