Effect of Rotor Angle Displacement on Synchronous Generator Transient Condition under Three-phase Fault

Abstract

Abstract: This paper approaches the effect of change of rotor angle upon armature current due to short circuit condition at the terminal of the synchronous generator. The synchronous machine as an AC generator, driven by the turbine to convert mechanical energy to electrical energy, is the major electric power-generating source throughout the world. The severest condition of three-phase shortcircuit waveform is naturally higher than the steady-state condition concerning with AC component of armature current, because armature reactances change due to armature reaction. The Park‟s equations are solved numerically during balanced three-phase shortcircuit. Under three-phase fault is applied at the terminal of the synchronous generator, the fault current waveforms of ia, ib, ic and iF are observed for the various rotor angle displacements, i.e, δ=0°, δ=30°, δ=60° and δ=90°. The transformed quantities are obtained from the projection of the actual variable on three axis; one along the direct axis, a second along the quadrature axis, and the third on a stationary axis. The interest is to study the wave form of the currents of the armature and field windings under three-phase short-circuit at the terminal of synchronous machine by using the MATLAB program.