Hybrid excitation synchronous generators for small hydropower plants

摘要

Modern rare-earth permanent magnets (PMs) can substantially improve the output characteristics of electrical machines. However, at the same time, the main flux created by PMs is not adjustable, and therefore, permanent magnet synchronous generators (PMSGs) are inappropriate for some applications where the reactive power regulation is required. To overcome this disadvantage, the researchers investigated hybrid excitation synchronous generators (HESGs) where the flux due to PMs is regulated with the help of field windings. The aim of this paper is to present a study of a direct-on-line HESG for small hydropower plants where reactive power regulation is required. This paper demonstrates the performance of all three different types of synchronous machines, that is a PMSG, a conventional electrically excitated synchronous generator (EESG), and an HESG, designed for small hydropower plants, and presents their comparison.