Religador automático para redes de baixa tensão

Abstract

Fuses are protective devices used in electric power distribution. Fuses are made of wire designed for melting in case of short-circuit or over-current, thus avoiding that the current of high value damage the circuit. Therefore, fuses have to be replaced everytime that this type of event occur. Another feature of those devices is the disability to distinguish between permanent and transient fault. New devices have been proposed to solve these problems by increasing the reliability of electric power system. Reclosers are examples of devices with the capacity to detect faults and disconnect the circuit without any replacement. Nowadays the reclosers that protect the electrical system are medium voltage. The present research intends to develop an automatic recloser to low voltage networks with the ability of distinguishing permanent faults from transient faults, allowing selectivity of the electrical system and enabling remote operation and automation of the line to which it is connected. The recloser is made of three main parts: voltage and current measurements devices, measurement data processing devices and disconnecting devices, that will open thecircuit. Each one of these parts is analysed, specied and described.