Investigation of a novel brushless electrically excited synchronous machine with arc-shaped rotor structure

Abstract

Electrically excited synchronous machines (EESMs) with brushes and slip rings are popular in many application fields. Nevertheless, the brushes and slip rings of EESM would increase maintenance cost and reduce the reliability. Addressing this issue, this paper proposes a novel brushless electrically excited synchronous machine (BEESM) with arc-shaped rotor structure, whose armature and field windings are placed on the stator. Firstly, the special structure and operation principle of the BEESM are illustrated and studied. Then, the electromagnetic performance indexes, including the air-gap flux density, flux linkage, back electromotive force (back-EMF), cogging torque, output torque and losses are fully analyzed by finite element method (FEM). Finally, the proposed BEESM is optimized to suppress the cogging torque. The results indicate that the proposed BEESM could serve as a high reliability and cost-effective candidate for the electricity generation system and industrial drive.

Keywords

• Brushless
• Electrically excited synchronous machine (EESM)
• Reliability