Protection for Generator Unbalance

The thesis deals with the problem of unbalance in generators and discusses various means of generator protection against the effects caused by this abnormal working condition. The general importance of the problem is described in the introductory part of this work. The theoretical section of the thesis contains an analysis of procedures applied to solve different types of unbalance by the help of the method of symmetrical components. As a central aspect of the topic, the causes of unbalance are examined. This investigation is realized together with a close insight into the diverse possibilities of unbalance reduction and, importantly, in respect the effects of negative sequence current on a generator and its components. The principles of generator protection against unbalance are described at the end of this section. In its practical part, this work deals with the procedure of protection setting and testing. The applied protection is an actual component of the REM 543 machine terminal as made by the ABB company. In order to facilitate the testing of the protection, we used the TZO3 electrical protection testing device provided by the EGÚ Brno, a. s. company. A summary of the most important information and measurement results can be found in the final part of the thesis