Temporal Causal Diagrams for Diagnosing Failures in Cyber Physical Systems
Abstract
Resilient and reliable operation of cyber physical systems of societal importance such as Smart Electric Grids is one of the top national priorities. Due to their critical nature, these systems are equipped with fast-acting, local protection mechanisms. However, commonly misguided protection actions together with system dynamics can lead to unintentional cascading effects. This paper describes the ongoing work usingTemporal Causal Diagrams (TCD), a refinement of the Timed Failure Propagation Graphs (TFPG), to diagnose problems associated with the power transmission lines protected by a combination of relays and breakers. The TCD models represent the faults and their propagationas TFPG, the nominal and faulty behavior of components (including local, discrete controllers and protection devices) as Timed Discrete Event Systems (TDES), and capture the cumulative and cascading effects of these interactions. TheTCD diagnosis engine includes an extended TFPG-like reasonerwhich in addition to observing the alarms and mode changes (as the TFPG), monitors the event traces (that correspond to the behavioral aspects of the model) to generate hypotheses that consistently explain all the observations. In this paper, we show the results of applying the TCD to a segment of a power transmission system that is protected by distance relays and breakers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 02, 2014
- Accession Number
- AD1002411
Entities
People
- Abhishek Dubey
- Anurag K. Srivastava
- Chen-ching Liu
- Gabor Karsai
- Nagabhushan Mahadevan
Organizations
- Vanderbilt University