Artificial identification system for transformer insulation aging

An artificial identification system to classify the insulation aging status of cast-resin transformer through current impulse method of partial discharge (PD) is proposed. The aging phenomenon of insulation materials belongs to a natural property and has strongly influences with the stability of power systems. Therefore, an effectively insulating identification technology plays an important role to enhance the system operating reliability. Since PD is a well known evidence of insulation degrading, a series of high voltage test with acceleration aging process to collect PD signals for identification system are conducted. Some selected statistical PD features instead of waveform are then extracted from these experimental PD signals as input data of the identification system. Also, an artificial neural network that combined particle swarm optimization is presented as the effectively identification tool. To demonstrate the effectiveness and feasibility of the proposed approach, the artificial identification system is applied on both noisy and noiseless circumstance. The experiment showed promising results with over 94% identification rate and even with 30% noise per discharge signal, an 85% successful identification rate can still be achieved. (C) 2009 Elsevier Ltd. All rights reserved.