detection of asymmetrical short-circuit faults and determination of the faulty line section in compensated transmission lines equipped with static inter-phase power controller based on signal processing techniques

The rapid advancements in power electronics and control systems have significantly contributed to the evolution of flexible ac transmission systems, enabling the development of increasingly sophisticated compensation devices. among these, the static inter-phase power controller has emerged as a novel and extended configuration of the traditional inter-phase controller, in which phase-shifting transformers are replaced by static synchronous series compensators, thereby offering enhanced controllability and operational flexibility. despite its technical advantages, integrating the inter-phase power controller into transmission networks introduces new protection challenges, particularly in accurately detecting fault locations due to the division of the line into two separate segments. this paper proposes a robust signal-processing-based method for detecting asymmetrical short-circuit faults and identifying the faulty line section in static inter-phase power controller compensated transmission systems. the approach employs statistical indicators derived from the cumulative sum method and correlation coefficients among phase currents. by applying a heuristic comparison framework, the algorithm reliably detects fault occurrence and classifies the faulty segment with respect to the inter-phase power controller location. the proposed method is implemented in a matlab/simulink environment and validated through extensive simulations covering 5,400 fault scenarios across various fault types, locations, and impedances. the results demonstrate an impressive accuracy rate of 98.46%, confirming the effectiveness and reliability of the algorithm under both nominal and stressed operating conditions.