Abstract
The paper gives first a brief résumé of previous work on tensor analysis of electrical machines. The steady-state equations of the synchronous machine are written in Park's reference axes, and from these the hunting equations are derived. It is then shown that these equations are part of a general group of transformations of reference axes of the synchronous machines, all of which are embraced by the general tensor equations. The hunting equations are then derived in a freely-rotating reference system. These equations are rewritten in tensor form and the significance of the grouping of terms into tensors is discussed. The latter equations are shown to give a more realistic interpretation of the hunting equations and the equivalent circuit.