Simulation of differential protections of transformers in power systems

In this paper the problem of wrong actions of relay protection (RP) and emergency automation (EA), including the transformer differential protection (TDP), is considered. It was found that this problem is caused by the discrepancy of TDP settings from the real operation conditions, associated mainly with the use of several gross simplifications in existing method of TDP settings calculation. Based on the research, presented briefly in this paper, it is concluded that the adequate mathematical models considering peculiarities of the specific implementations and processes in current transformers (CT) and integrated into the appropriated aids, in particular, into the program - mathematical modeling of TDP designed by the author of the article, are effective tools for testing and optimizing of TDP settings.