Centralized Fault-Location and PMU Placement Strategies in Weakly Observable Grids: A Comprehensive Review

This review addresses the critical challenge of ensuring electrical power system reliability through optimized wide area measurement system architecture and centralized fault management. The primary contribution of this study is a systematic comparative synthesis of optimal phasor measurement unit placement strategies and centralized fault localization methods tailored specifically for weakly observable networks. The paper critically evaluates the mathematical foundations, computational constraints, and trade-offs of both deterministic optimization techniques and non-deterministic data-driven algorithms (heuristic, metaheuristic, and machine learning). Furthermore, we establish a unified framework for data preprocessing workflows within Phasor Data Concentrators, identifying how noise filtering and missing value recovery impact downstream diagnostic accuracy. Based on a rigorous cross-analysis of literature benchmarks on IEEE test systems, this review demonstrates that hybrid frameworks combining digital signal processing with machine learning yield superior real-time adaptability. Finally, we map out a targeted research agenda focusing on next-generation grid maintenance, including advanced relay protection monitoring and anomaly detection for non-technical losses.