Transformer Fault Detection by Frequency Response Analysis
Vikash.M*, Sharlinprija.K*, Ilampoornan.M.K**, (*Students M.E-Power Electronics and Drives, **Professor-EEE Dept.) Loyola Institute of Technology, Chennai-600 123. TamilNadu,India
Abstract: Power transformers are one of the most vital as well as expensive equipment in an electric power system. Therefore, it is the responsibility of utilities to decrease the transformer lifecycle costs and to increase the usable service time. The damage may cause a change in the physical condition of transformer which would be reflected in the electrical parameters- resistance, inductance and capacitance. The insulation performance is influenced by thermal, electrical and mechanical stresses. The displacement of windings can occur during transportation of transformers or during a short circuit near the transformer in the power system. The Frequency Response Analysis (FRA) can detect the type of fault and the exact location of fault. The result obtained for the various fault condition is compared with the reference set and the conclusion are drawn.
II. SHORT CIRCUIT FAULT IN WINDINGS System short circuit may occur across any two lines or if the neutral point is earthed between any one lines. The effect of system short circuit will produce over currents, magnitude of which are dependent on the system MVA, feeding the fault or the voltage, which has been short circuited and on the impedance of the circuit up to the fault. Short circuit may cause winding movement and shorted turns. Short circuits near transformers usually cause currents of high amplitudes. This leads to extreme mechanical stress of core and coil assembly. The mechanical forces do not always cause a failure. Sometimes there is only some significant damage, which are not recognized and further service is not possible. III. SHORT CIRCUIT FORCES
This project proposes to detect short circuit faults between two turns in a winding...