Geometry optimization of synchronous machines used on ship shaft generator systems

摘要

In this paper, the geometry optimization and analysis of two synchronous machines for ship shaft generator applications was carried out. The use of shaft generators in marine applications is a convenient and effective way to supply electric energy to the ship, operating in conjunction with conventional diesel generators. On a first step, state of the art topologies of shaft generator systems are identified and evaluated. In addition, potential improvements in shaft generator systems are proposed. On a second step, a low-speed, direct-driven Permanent Magnet Synchronous Generator (PMSG) for shaft generator applications is designed and optimized in terms of torque production as well as efficiency. The PMSG is compared with an equal power Salient-Pole generator driven by a step-up gear, which is a set-up commonly used in shaft generator systems. The machines are evaluated and optimized in terms of torque production, efficiency and electromotive force's (EMF) harmonic content in nominal operating conditions.