Risks in isolated earth or high impedance grouding systems at the laúca hydroelectric power plant
Keywords:
High impedance, Grounding, Synchronous generator, Grounded neutral, Isolated systemAbstract
The aim of the study was to understand the risks associated with earth-isolated systems and high-impedance faults, focusing on the grounding of the neutral of the synchronous generator at the Laúca hydroelectric power station. Using a qualitative-quantitative methodology, based on descriptive and explanatory research with exploratory and observational procedures, the behavior of electrical current and voltage during single-phase faults, the selectivity of earth-insulated systems and the risks to which technicians are exposed when measuring the voltage of the grounded high-impedance neutral directly on the primary circuit of the grounding transformer were analyzed. The results showed that earth-insulated systems are not selective, making it difficult to detect single-phase faults. The analysis of the Laúca power station case highlighted the dangers of measuring neutral voltage with unsuitable equipment, such as multimeters isolated at 1 kV, exposing technicians to significant risks. It was concluded that it is crucial to adopt safe and appropriate practices for measuring neutral voltage, guaranteeing the effectiveness of electrical protections and operational safety. The study reinforces the need to understand the risks of these systems and implement technical solutions that minimize failures, promoting safety and efficiency in hydroelectric plants. The education and training of technicians is also essential to reduce the risks associated with these operations.
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