F313 Rewind of Four Water Cooled Generators in South Korea

抄録

This paper will focus on four successful generator rewinds performed at the Inchon and Honam power plant stations in South Korea. These four generators are owned by KEPCO Korean Electric Power Company). Since this project was complete, along with the successful continue operation of these units, NEC has rewound, or supplied coils for, additional large, water cooled generators, ranging up in size to a maximum of 945,000kVA. These types of rewinds demonstrate to power plant owners, that often, the most cost effective repair is a rewind and upgrade by a qualified non-OEM company, such as NEC. These units were designed and rewound from 1997 to 2001,and have been operating successfully since their initial startup. Electrical generators, in the Power Industry, overall have has an enviable history of high efficiency and high reliability. Although there have been significant, generic problems by the major manufacturers throughout the years (i.e., tooth top cracking, copper dusting, etc.), none may be as costly as the current problems occurring on water cooled generators. These units, in service for the last 10 to 20 years, often develop cooling water leaks, neutralizing the high voltage electrical insulation, leading to failure of the bar, and many times replacement of the entire stator winding.