Generator Life Extension, Performance Upgrade and Maintenance Process Improvement
(Room Garuda 10B, 1st Floor)
18 Sep 18
4:00 PM
-
5:30 PM
Tracks:
TRACK C - Optimizing Plant Operation
KOSEP(Korea South East Power Company) Yeongdong Division has pursued continuous changes since 1973 by carrying out major fuel transition project 2 times from anthracite to bituminous and to wood pellet. At present, it has placed the leading eco-friendly power plant which is also the first and the biggest wood pellet firing plant in Korea. In accordance with division’s change, we had finished a project to extend generator lifetime. Yeongdong Unit 1 generator has capacity of 125MW(147MVA) and is hydrogen cooled 3 phase synchronous generator which is operated more than 40 years without major replacement except rotor re-winding in 1991. In concern about equipment failure because of thermal/mechanical stress and also about exceeding designed lifetime, we diagnosed generator status. From deteriorated stator condition such as development of powder on stator end winding, displacement of stator slot liner, discoloration of windings, we concluded overall aging and performance degradation on unit 1 generator. We started a major project to extend generator lifetime as a response. This project was about not only stator/rotor re-winding and subsidiary equipment replacement but also improving equipment by adopting up-to-dated technology. Insulator’s better grade and performance led higher efficiency as well as equipment reliability. Material change of retaining ring to non-magnetic substances prevented deformation caused by long term operation. Maintenance process was also improved by making generator rotor uninstallation tool. This special tool helped rotor disassemble work to be easier, more safe and faster. Such a large scale project to extend lifetime of generator which was operated long period of time, is unique and would be difficult to find similar cases. We hope to share our experiences with Asian power generation industry about the process from status diagnostics to life extension, improvement on generator itself and maintenance procedure.