Fundamental Concepts of Synchronous Machine Reactances

This educational paper presents fundamental concepts of synchronous machine reactances in a form suitable for college seniors and recent graduates. Part I builds up the ``physical concepts´´ of flux linkage and inductance, part II applies the concepts to synchronous machines, developing a physical picture of machine reactances. Part III starts with the fundamental circuit differential equations of a machine and obtains expressions for the reactances in terms of self- and mutual inductances, ending with the machine equations in the direct, quadrature, and zero axes, which give a physical picture of the machine ``viewed´´ from these axes.