It is necessary to break the technical barrier and make breakthroughs in information system

control system

device and other aspects when reforming large thermal power excitation system domestically. The article first systematically concludes and summarizes the key technologies of modern excitation technology

including control and command subsystems

communication subsystems

rectifier subsystems

and excitation subsystems. It analyzes and summarizes the research status

existing problems

and difficulties involved in each technology at home and abroad. Secondly

the localization and replacement process of the HN-i6200 excitation system for largescale supercritical 670 MW thermal power units was described. Targeted design was carried out to meet the special requirements of the excitation system operation for thermal power units

and highly reliable domestic DC breakers were developed. Through experimental research

the operation strategy of the excitation system for thermal power units was overcome

and a nationally produced HN-i6200 excitation system was successfully developed. The onsite testing and system modeling have verified the working performance of the nationwide production excitation system

providing technical and practical references for the localization of excitation technology in the power industry.