Maintenance of the generator rotor: 9 important lessons the following list consists of lessons of the utilities that have rewound their generator rotor and renovated. “Best practices” in Appendix A, these lessons in fairly large groups of similar experiences are arranged, and the order provides no special precedence or importance of a particular lesson. Not all lessons are applicable to each generator; We recommend readers to review the entire list and determine what lesson is for their own units of importance. Repeat some of the lessons learned”may the best practices” which are provided by the other utilities in the Appendix A. In the course of the repair of many types of Turbo rotors has been found that many runners not specifically designed for the application and the environment, where the generators were used. Clarifications and notes on the design of the hydrogen seal and seal oil flow rates, are important if the new rotor to be changed.
Change of hydrogen seal design, especially if no original equipment manufacturers are the new rotor and stator, can lead to various oil flow requirements and various dense columns. The replacement of tension crack corrosion prone fixing ring with not susceptible to rings, and the stress relieve of the rotor teeth can extend the useful life of the rotor. Fatigue cracks in Rotornut teeth can occur often, especially outside the snap-ring groove. The cracks are caused by cyclic stress on the teeth. This problem is not restricted to a particular type of generator or a specific manufacturer. It can occur in each rotor, where the teeth between the Nutkeil and the retaining ring are trapped.
The design modifications of the rotor may be required to reduce the fatigue cracks, low-cycle-fatigue of the retaining ring seats and pole to pole connection with generators, not specifically designed for long service life. Several new studies show that a significant proportion of the installed generators with short circuit coils work. Without emergency planning, to edit any errors, the duration of a ungeplannten failure can be extended by rotor failure after days, weeks or even months. A river sample monitoring system should be used. It requires monitoring at different impact points. Running first often, until is established a database of operating conditions. The cycling of the Gnerators is the main cause of failure, deterioration of the insulation, and general deterioration of the generator area. The running of the generator at a constant load and with less action and shut down will help to minimize these problems. Two shift creates accelerated wear and fatigue on the components of the rotor, such as pole-to-pole connectors.