Table 2 Summary of different techniques used for protection coordination of sub-transmission systems
Technique | Main feature | Merits | Demerits |
|---|---|---|---|
Intelligent distance to over current relay coordination [62, 64] | Performs the coordination operation of distance and over current relays | Utilizes the different standard time inverse over current relay and optimized zone-2setting of distance relays for coordination. | No hardware implementation reported. |
Definite time based distance to over current coordination [66] | Definite time based over current relays are coordinated with distance | Simple in implement | Over current relays have fixed operating time. |
Optimized coordination for series compensation line [67] | Multiple relay settings are identified for different level of series compensation | Applicable for varying degree of series compensation. | Real-time implementation challenges |