Optimization of Inrush Current in Electrical Transformer

Paper narrates the optimization of residual flux in network transformers by using MATLAB Simulation. The purpose of the paper is to mitigation a large inrush currents taken by various transformers when a feeder is energized. Here Time-domain simulations are used to prove that a small-power device can substantially reduce the residual flux of all transformers simultaneously. The device used in this paper consists of a low-voltage dc source. Before a feeder is re-energized, the residual flux is reduced to a minimum level and as a consequence, the large inrush currents are reduced to an acceptable level. This greatly improves the probability for the feeder to be successfully energized when otherwise a false trip would have occurred. Inrush current reductions of more than 60% are obtained at the head of the feeder.