Virtual relay design for feeder protection testing with online simulation

The aim of this study is to design and implement an accurate virtual model of a basic feeder protection relay. The work focuses on certain sets of ANSI functions and COMTRADE (Std C37.111) to interact with an online simulation subjects to different fault scenarios. The proposed methodology includes robust synchronization between power system simulations and the response of the virtual relay. The results validation integrates a distribution system simulation software running with remote control for time-based simulation, then it reproduces voltage and current signals with the virtual relay operation. The performance is assessed in three cases of study comparing real protection equipment and the operation of the virtual relay at the same fault scenarios. This work is the next step of the attempt to reach a versatile test engine for substation automation systems, including multiple protective virtual devices which reduces costs and allows to assess critical protection schemes.