Dimensionamento de um dispositivo para detectar avarias em cabos subterrâneos

Abstract

The growing concern with safety and the increase in infrastructure in densely populated urban areas, as well as the search for aesthetic preservation, has required the installation of underground networks. Although they are devoid of some faults that occur in overhead lines, they have similar short-circuit faults as well as open-circuit faults. Locating the exact position of any of these types of faults is an arduous, expensive and time-consuming process as the system is not exposed. Thus, the need to design a device to detect such malfunctions is perceived. The following project presents a proposal for the design of a device to detect faults in underground cables. Ohm's first law will be used to determine the resistance between two short-circuited conductors and thereby know the location of the fault. In the case of open circuits, the phenomenon of the discharge time constant of the capacitors is used to determine the capacitance formed between two conductors and, with this, to estimate the distance at which the fault is. The device will have a DC power supply, a control unit that will carry out operations to estimate the location of the fault, an LCD display unit, a circuit used to measure the resistance of the conductors, and a circuit used to measure the capacitance between two conductors of a cable.