Analysis and Design of Distance Protection Scheme

Abstract

Maloperation of over-current relays for low voltage system can be tolerated as the supply to consumers has to be supplied continuously but cannot be tolerated for EHV system. Distance protection, or distance relay, is a type of protection system which detects fault within preset zone of transmission lines and hence enabling the necessary actions to isolate the faulted lines. This device is required to provide reliability in the protection system of transmission lines, avoiding loss of load or loss of synchronism in case of disturbances. The operation of distance relays is influenced by different factors such as mutual compensation, load encroachments, power swings etc.; hence affecting its performance. To ensure its reliable operation, various settings parameters will be studied and recommendations will be provided based on the analysis and calculations. Here, analysis on the different types and make of Distance Protective Relays will be done, e.g. MiCOM P441,442,444, REL 670. Based on that analysis and calculations, software based modeling will be done for different characteristics for Distance Relays. Operation of relay during power swing will be studied and its operation will be analyzed.