Performance evaluation of transmission lines protection using Real Time Digital Similator (RTDS) and SEL311-L

This thesis, we will conduct evaluation and testing of Schweitzer Engineering Laboratories Line Current Differential Protection and Automation System (SEL-311L) using Real Time Digital Simulator (RTDS) for each protective element of the relay. First, we build very large power system model representing portion of California power rid and use Computer-Aided Protection Engineering (CAPE) software to reduce system into a seven buses equivalent system. We also use Positive Sequence Load Flow (PSLF) to get power flow into and out of each bus. Finally, we use RSCAD software to build the model with given data from CAPE and PSLF and validate the result. Finally, we place two SEL-311L protective relays at each end of the transmission line and set them up and examine different protective elements and evaluate their performance. We will make a comparison of elements with each other and rank them according to trip condition. The steps how to execute each different kind of software will be presented