This paper presents an experimental investigation into multi-diode open-circuit faults in the rotating rectifiers of brushless synchronous generators. Unlike single-diode faults, multi-diode faults introduce complex electrical behavior by reconfiguring conduction paths and altering rectifier topology. Representative fault scenarios, categorized from Class 3 to Class 8 are examined under no-load conditions to isolate excitation system dynamics. Key electrical quantities, including exciter armature currents (  -  ), rectifier output voltage ( ), main field current ( ), exciter field current ( ), and generator terminal voltage (  ), are evaluated. The results show that electrical characteristics are governed by the effective conduction paths and the resulting rectifier structure rather than the number of faulty diodes. Depending on the fault condition, the rectifier transitions move transitions from asymmetric three-phase rectification to single-phase full-wave or half-wave rectification. These structural transitions lead to amplitude reduction and the emergence of dominant frequency components, particularly at 60 Hz and 120 Hz. The findings provide a structural interpretation and electrical characteristic analysis of multi-diode faults.

서 론
재료 및 방법
    실험의 구성 및 계측 방법
    다중 다이오드 개방 고장의 분류와 정류 구조 기반 재해석
결과 및 고찰
    실험 결과
    Class 3 개방 고장
    Class 4 개방 고장
    Class 5 개방 고장
    Class 6 개방 고장
    Class 7 개방 고장
    Class 8 개방 고장
    실험 결과 분석
결 론
References

• 류기탁(한국해양수산연수원 해양기술교육팀 교수) | Ki-Tak RYU (Professor, Ocean Technology Training Team, Korea Institute of Maritime and Fisheries Technology, Busan 48562, Korea)
• 이윤형(한국해양수산연수원 해양기술교육팀 교수) | Yun-Hyung LEE (Professor, Ocean Technology Training Team, Korea Institute of Maritime and Fisheries Technology, Busan 48562, Korea) Corresponding author