Excitation System Technologies for Wound-Field Synchronous Machines: Survey of Solutions and Evolving Trends

Abstract

Wound-field synchronous machines (WFSMs) are included in the majority of large power generating units and special high-power motor drives, due to their high efficiency, flexible field excitation and intrinsic flux weakening capability. Moreover, they are employed in a wide range of high-end solutions in the low-to-medium power range. This contribution presents a comprehensive survey of classical and modern methods and technologies for excitation systems (ESs) of WFSMs. The work covers the fundamental theory, typical de-excitation methods and all the modern excitation equipment topologies in detail. It also includes a description of the state-of-the-art and the latest trends in the ESs of wound-field synchronous motors and generators. The purpose of the paper is to provide a useful and up-to-date reference for practitioners and researchers in the field.

High-Power Machines and Starter-Generator Topologies for More Electric Aircraft: A Technology Outlook

“…Moreover, the excitation current can be controlled to achieve the needed flux de-regulation capacity. In addition, a redundant de-excitation circuit improves the security for the S/G [117]. This because it has the opportunity to eliminate the fault current shortly after a short-circuit or a high voltage occur.…”

“…For faster dynamics, rotating power electronics (RPE) is needed on the shaft of the MG, where a lot of different solutions exists [126]- [128]. There is also a myriad of available exciter-less solutions that eliminates the need for an external source to the ME [117].…”

Electrical Machines and Power Electronics For Starter-Generators in More Electric Aircrafts: A Technology Review

“…The field current can be controlled to achieve the necessary flux weakening capability. In addition, a redundant de-excitation circuit improves the safety for the S/G [39]. This because of the possibility to cancel the fault current when short-circuits or high voltages occur.…”

Future Operational Regimes of Bulk Power Generation in The Era of Global Energy Transition: Grid Codes, Challenges and Open Issues

“…Nowadays, a new product line of generators [6] have been argued. In addition, different types of synchronous machines for various applications employ very different excitation systems [7]. The grid codes for different machines and types of systems do also vary [8].…”