Improvement in the 《Generator-transformer》unit earth-fault protection

摘要

Ways for increasing the effectiveness of the unit single-phase earth fault protections are considered. Methods are proposed which make it possible not only to check the insulance of a network with insulated neutral whenequipment is on operation but also to determine the character of the insulation deterioration process and to detect domage location. The methods are based on an analysis of signals formed with the help of a high-voltage switchgear. Shemes of devices which realize the methods proposed and recommendations on their use are given