Autotransformers (ATs) have been widely used for many years. For large size ATs, a tertiary winding is usually included. Sometimes the tertiary winding is loaded for station service, local loads, VAR compensation, etc. Other times, the tertiary winding is buried and acts as stabilizing winding which provides a path for zero-sequence current and 3rd harmonic current. Three-winding ATs present so...

This paper presents the use of ANN as a pattern classifier for differential protection of power transformer, which makes the discrimination among normal, magnetizing inrush, over-excitation, external fault and internal fault currents. The Back Propagation Neural Network Algorithm and Genetic Algorithm are used to train the multi-layered feed forward neural network and simulated results are comp...

A feed forward neural network (FFNN) has been trained to discriminate between power transformer magnetizing inrush and fault currents. The training algorithm used was back-propagation, assuming initially a sigmoid transfer function for the network’s processing units (“neurons”). Once the network was trained the units’ transfer function was changed to hard limiters with thresholds equal to the b...

259 Lines are protected by overcurrent-, distance-, or pilot-relaying equipment, depending on the requirements. Overcurrent relaying is the simplest and cheapest, the most difficult to apply, and the quickest to need readjustment or even replacement as a system changes. It is generally used for phaseand ground-fault protection on station-service and distribution circuits in electric utility and...

Power transformer is a major component of power system and it’s correct functioning is vital to system operations. It is quite expensive and has no substitute for it’s major role. It is therefore, very important to closely monitor the in-service behavior to avoid costly outages and loss of production. Many devices such as Buchholz relay and Differential relay have been evolved to monitor servic...