Dissertação de Mestrado
Estudo de descargas elétricas induzidas em subestações de alta tensão: soluções para mitigação e monitoramento
Geraldo Magela Gontijo
High intensity electric fields are intrinsic to extra-high voltage substations, where the effects are particularly pronounced. The work at non-energized areas, but in the vicinity of energized of high-voltage bus bars, may lead to discomfort in the workers due to the spark discharges between people and metallic objects. The resulting electric shocks are very annoying and present risks of fall from the structure, due to the involuntary impulsive reaction to the shock. In this context, the question involving the discomfort and the risk of fall from the structure requires theoretical and experimental studies aiming the development of devices to allow the workers to execute their tasks without discomfort and in a safe condition. As explained above, the proposal of this dissertation is to consolidate a theoretical base concerning the effects of the electric fields in the human body from literature review, field surveys and tests in laboratories and substations, aiming to present contributions for the development and implementation in CEMIG of the devices for mitigation of sparks discharges during work in high voltage substations; improvement of a methodology of evaluation of undisturbed electric field, from studies regarding the correlation between leakage current through the workers body and electric field. This methodology satisfies a present need for the evaluation of levels of exposition to the electric field prior to the work in energized substations, as an instrument for occupational healthy investigation, looking ahead to some prescribed normative aspects in Brazilian standard NR-10; and, finally a knowledge base updates regarding the work under high intensity electric fields exposure, through the literature review and its adequacy to the new available electric field probes and software for modeling and simulation of electric fields.