A new method for calculating the q-axis saturation characteristics of salient-pole synchronous machines

For the accurate analysis of salient-pole synchronous machines using the two-axis frame models. The direct- (d-) and quadrature-axis (q-) saturation characteristics are needed. Usually the direct-axis saturation characteristic can be obtained easily by the conventional open-circuit test with the machine excited from its field winding. On the other hand, the quadrature-axis saturation characteristics of synchronous machines cannot be measured applying simple, conventional methods and, thus, they are usually not available. This paper presents a new method for calculating the quadrature-axis saturation characteristics of salient-pole synchronous machines. In this method, the quadrature-axis saturation characteristic can be calculated from the readily available test data. Namely the direct-axis saturation characteristic, and the direct- and quadrature-axis unsaturated magnetizing reactances