Performance Equations for DC Commutatorless Motors Using Salient-Pole Synchronous-Type Machines

A large volume of research has been done to analyze commutatorless dc motors using salient-pole synchronous-type machines. These studies have not resulted in clear design-oriented expressions relating performance to machine geometry. The development of design-oriented algebraic expressions of machine performance measures in terms of machine inductances is described. Speed independent equations for commutation angle, commutating current, critical angle, safety angle, average and instantaneous torques, and instantaneous damper currents are developed. Shunt- and series-type machines are analyzed, and numerical examples of both are included.