The Real Time Digital Simulator (RTDS) is a tool for the design, development, and testing of power system protection and control schemes. RTDS can be used for the investigation, development, and integration of new and complex power system components. The user is able to study both the device itself and the response of the existing power system to its operation (or misoperation). The Hardware in the Loop (HIL) test provides an opportunity for understanding the behavior and validating the model of physical device. In the HIL simulation, parts or components of the virtual power system are replaced with physical devices. In the Software in the Loop (SIL) simulation, the software model replaces the physical protective device. This paper presents the modeling and testing of a Schweitzer Engineering Laboratories (SEL) 351S protective overcurrent relay using RTDS. The first part of the paper discusses HIL tests conducted with the physical SEL 351S overcurrent relay for an eight-bus power system. The second part discusses the development of a software relay model in RSCAD and real time SIL simulation. The results obtained by conducting the real time HIL are presented and procedure to conduct the SIL tests is proposed.
A. Saran, P. Kankanala, A. K. Srivastava, N.N. Schulz, Grand Challenges in Modeling & Simulation, Summer Simulation Conference (SummerSim), 2008 Edinburgh, Scotland
KEYWORDS: Hardware in the loop, software in the loop, real time digital simulator, overcurrent relay, line protection