Exploring Self-Organized Criticality Conditions in Iran Bulk Power System with Disturbance Times Series

Ubiquitous power-law as a fingerprint of Self-Organized Criticality (SOC) is used for describing catastrophic events in different fields. In this paper, by investigating the prerequisites of SOC, we show that SOC-like dynamics drive correlation among disturbances in Iran bulk power system. Existence of power-law region in the probability distribution is discussed for empirical data using Maximum likelihood estimat­ion. To verify the results, long time correlation is evaluated in terms of Hurst exponents by means of statistical analysis of time series including Rescaled Range (R/S) and Scaled Windowed Variance (SWV) analysis. Also, Sensitivity analysisshowed that for correct inference in existence of SOC in power systems, all disturbances should berecorded to be used in statistical analyses. Greater thresholds for recording disturbances lead to underestimate the Hurst exponent.