Simulation and demonstration for transmission line protection in educational and industry training programs

This paper describes the philosophy, development and use of software package which assist in the analysis and demonstration of some fundamental concepts associated with power system protection, especially transmission lines. A commercial digital line protection device (RCS-901) is selected as object to be simulated which is widely used in the EHV transmission line in China. It can use both fault recorder data and EMTP simulation data. As a basic analysis tool for line protection, the software provides several analysis modules, including line pilot protection, impedance protection using PFFC, distance protection, zero sequence protection. Also it has various kinds of digital filtering in protection relays. Each module can illustrate the detail of interior data process and can replay the fault waveform and event data. The results of the software simulation are consistent with the protection device (RCS-901). It is applicable to both academic power programs and industry training efforts.