Corona Protection Systems for Generators with Un > 20 kV

Inhalt:
The special importance of the corona protection system for the function of the entire insulation system calls for special efforts in R&D as well in quality control. The prime demands are: 1. Stable function at operational conditions; 2. Stable and simple system; 3. Cope with the special stress situations at acceptance tests. These requirements are met by one single system available as paint or tape, based on the same silicon carbide (SiC) material. It will be shown that this system can be used up to the most demanding types of generators, i.e. indirect air cooled generators with Un=23 kV (operating) and 25 kV (in evaluation). In order to reach this, long time R&D efforts both in theory and experiment were needed. The theoretical considerations are discussed here only briefly and the main accent is put on the presentation of experimental work.