Custos de paradas de processos industriais devido a afundamentos momentâneos de tensão

Abstract

With the advent of electro-electronic technology, the industries have invested in systems and equipment in order to increase productivity and quality of their products. At the same time, researchers indicate that, linked to their use the equipment and systems bring great sensitivity in their operation which impacts on production continuity, generating significant economic losses for companies, especially those in the industrial sector. Short-term voltage variations, mainly when there are momentary voltage sags bring very serious consequences for consumer units, especially for those industrial units with sensitive loads. It is, therefore, essential that studies on costs of interruption in industrial processes due to voltage sags begin to be prioritized by electric energy concessionaires and researchers, so that the results start contributing to the improvement of the image and relationship between the concessionaire and its customers, as well as for the academic society, technicians and agents of the electric sector. The objective of this work is to present the results of a methodology to obtain the costs of industrial stoppages due to momentary voltage sags. This is a direct survey, through a questionnaire with the consumer units, composed of several industries supplied by medium voltage networks granted by EDP – Energias de Portugal. Initially, 70 industries were selected, of which 60 were chosen by EDP itself. Of this total, 33 agreed to participate in the research. They are classified into 12 different types of activities, thus allowing an assessment of costs per event and per installed demand. The research was supported by an ANEEL R&D project by EDP, covering industries from the southeast region (São Paulo and Espírito Santo) and its results were very coherent compared to the few estimations that may be found in the literature, although these are related to shutdowns in general. Crowning the work, the costs found were used in order to have a broader evaluation (annual costs) from existing measurements at EDP, considering shutdowns that happened in 61 substations’ busbars in the states of ES and SP. Finally, it is worth mentioning that this research brought a relevant technical contribution to the Brazilian electricity sector, helping to fill gaps in the national literature when this subject tries to be addressed.