Graphical determination of magnetic fields: Practical applications to salient-pole synchronous machine design

There are three methods of obtaining the flux distribution in a magnetic field. First: By test. Templates or models can be made of the field to be explored and the flux distribution can be obtained by test as described in a companion paper “Graphical Determination of Magnetic Fields — Comparison of Calculations and Tests” by Messrs. E. E. Johnson and C. H. Green. Second: By mathematical analysis. This method is accurate and consistent results can be obtained. If the problem is very complicated, however, the mathematical solution is very laborious and sometimes impossible. Third: By the graphical method. This method is quite accurate and it can be used for design calculations. It is comparatively easy and it is the quickest method of the three. The graphical method of plotting magnetic fields used in this paper is described in a companion paper, “Graphical Determination of Magnetic Fields — Theoretical Considerations” by Messrs. A. R. Stevenson, Jr. and R. H. Park. This paper shows how the graphical flux plots can be used very successfully in design calculations. In fact, the performance characteristic of a salient-pole synchronous machine can not be predetermined accurately without the use of flux distribution coefficients.