Study of mutual influence of measuring part elements of transformer differential protection and its impact on the primary signal processing

摘要

Calculation of relay protection (RP) settings ensuring its adequate functioning under specific operating conditions is extremely difficult task. The main prerequisite for solving this problem is availability of a detailed analysis of functioning of key elements of RPs schemes in the specific conditions of its operation. That is possible to do with adequate RPs mathematical models and modern EPS simulators. Based on developed by authors approach for detailed RPs simulation the models of the whole circuit of measuring part (MP) of numerical transformer differential protection were developed for different types of auxiliary transformers and low-pass filters. A comparative numerical analysis of its impact on the primary signal processing is carried out, including taking into account the magnetization current transformers. Summarizing, the theoretical and practical studies presented in the article allows formulating requirements for RPs' detailed mathematical models, which will be used in the further research.