A new algorithm to prevent maloperation of distance protection zone 3 during wide‐area disturbances

摘要

This paper presents a new algorithm to avoid cascading tripping of interconnected transmission lines caused by maloperation of zone 3 distance relay during major power system disturbances. Blocking of zone 3 distance relay and the application of static var compensator controllers are the 2 corrective actions that proposed algorithm use to protect the power system from cascade tripping. Distance relay zone 3 blocking is achieved using real-time information about the balance between generation and load in each area of the power system. However, the static var compensator controller allows injecting, rapidly and efficiently, necessary reactive power in the system to mitigate the disturbance development during the blockage of the distance relay protection. Results of dynamic simulation on 400kV Turkish transmission system, using SECRE software, are presented to demonstrate the effectiveness of the proposed algorithm. Simulation results clearly indicate that the use of this algorithm can improve reliability of zone 3 distance relay operation, enhance the stable operation of power system, and can limit the spread of cascading outages during wide-area disturbance.