Uma contribuição para a medição das componentes de correntes de descargas atmosféricas através de transdutores resistivos

• Ano de defesa: 2007
• Autor(a) principal: Antonia Navarro Gomez
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Engenharia Elétrica; Engenharia elétrica
• Link de acesso: http://hdl.handle.net/1843/BUOS-8CVFKL

In this work, a system is developed for direct lightning current measurements in instrumented towers. This system uses resistive transducers and allows the measurement of both the impulsive and continuous components of the lightning current. The design of the transducer is described in detail, as well as the characteristics of the electronic system applied to monitoring and recording the measured signals. Due to inductive effects, the application of resistive transducers to measure impulsive lightning currents may lead to errors, especially in the wavefront and in the peak current. To minimize these eventual errors, two different aspects were dealt with: firstly, the resistive transducer was designed to have a special shape to reduce inductive effects (coaxial shunt); secondly, a correction function was derived analytically to compensate the residual inductance of the shunt. Laboratory experiments were performed in order to evaluate and calibrate the measuring system and the transducer itself. Such experiments considered the injection of typical lightning currents. Once the performance of the measuring system was considered satisfactory, it was incorporated to the Morro do Cachimbo Station. The results derived from an actual lightning strike on the tower are presented here. Given the good performance of the measuring system in both laboratory and field conditions, it was decided to definitely incorporate it to the Morro do Cachimbo Station.