Model-based design of a protection scheme for shipboard power systems

The focus of this paper is the design and implementation of an advanced protection scheme for shipboard power systems (SPS) using model- or simulation-based techniques. An overcurrent scheme has been adopted as proof-of-concept application. By designing a model and hardware prototype, advanced adaptive protection schemes can be developed. The protection system is designed to minimize the effects of faults on the SPS, which presents challenges, such as increased fault vulnerability and lack of an electrical ground in the system. The development of elaborate digital protection devices for SPS requires appropriate tools for modeling, simulation, and testing. Different software and hardware prototyping tools were used in the present work. First, MATLAB/Simulink was used to model the whole system including the protective device. The Virtual Test Bed (VTB) and RSCAD (RTDS software package) were used to model the entire system for comparison purposes. The power system was then modeled using an electromagnetic transient real-time simulator such as RSCAD or VTB-RT. The protective device was thoroughly modeled in MATLAB/Simulink and then downloaded to a dSPACE controller board, which was interfaced with one of the real-time simulator to perform the corresponding hardware-in-the-loop (HIL) tests. The results of these HIL tests were then compared to similar tests using a commercial protective device, the SEL-351-S relay.