Structural analysis for assessment of monitoring possibilities: Application to simple power system topologies

Any power system, either an integrated power system in an all-electric ship or a utility power system, needs to be highly reliable. Reliability of a complex system strongly depends on the possibility of detecting faults and isolating them from each other, i.e., on the monitoring potential of the system. The area of power system engineering that is concerned with the fault detection and isolation is called protection. As power systems becoming more and more complex, current standards for their protection should be adjusted accordingly to meet the challenges associated with increased system complexity. The standard approach used in power system protection is local, that is, current and voltage sensors are placed at or near individual breakers that open up to isolate a fault (short circuit). Coordination between breakers is achieved indirectly by setting the voltage or current trip points of the breakers differently so they open up in a desired sequence. Wide-area (global) protection is a new research direction. Wide-area protection schemes provide protection at more unified, global level than local protection schemes, and often operate as a backup level of protection. However, these schemes are usually developed manually, that is, the arrangement of protective actions within areas are made by hand, following heuristic considerations. More systematic and automated approaches are required for successful wide-area protection of larger systems. The objective of the current study is to adapt the model-based fault detection and isolation approach based on structural analysis to power systems in order to evaluate the monitoring potential of a given power system topology (architecture) in a systematic and automated manner. A new methodology is applied to evaluate the monitoring potential of a few simple topologies.