Fuzzy based approach for the safety assessment of human body under ELF EM field considering power system states

This paper presents a study on the fuzzy based approach for the safety assessment of a human body under ELF electric and magnetic (EM) fields considering power systems. The analysis of ELF EM field based on quasi-static method is introduced. Up to the present, the analysis of ELF EM field has been conducted with the consideration of one transmission line, or a power line model only. In this paper, however, the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes and the states are classified into two types, normal state resulting from normal operation and emergency state from outages. In order to analyze the uncertainty in the normal state, the Monte Carlo simulation, a statistical approach was introduced and line current and bus voltage distribution are calculated by a contingency analysis method, in the emergency state. To access the safety of the human body, the approach based on a fuzzy linguistic variable is adopted to overcome the shortcomings of the assessment by a crisp set concept. In order to validate the usefulness of the approach suggested herein, the case study using a sample system with 765 kV was done. The results are presented and discussed.