The traditional infrastructure of power system industry is presently going through large amount of change that consensus over the improvement of power quality for fulfilling this requirement electronically automated devices having high sensitivity toward the disturbance in the power system signals are under the major consensus of research activities. The low power quality signal is responsible ...

Transformers are major elements of any power systems. Normally they must be properly protected by differential relays. This protection system should be precise and reliable via implementation of strong algorithms that able to differentiate between faulted and unfaulted condition to fully grantee of power continuity. This system should be able to detect the non-faulted condition, such as inrush ...

New types of appliances sometimes bring unexpected power quality problems. On several locations it was reported that energy-saving lamps cause random false tripping of circuit breakers. In all of these cases these lamps had electronic drivers. An investigation of this phenomenon is presented in the paper. Laboratory measurements were done on several types of LED and gas-discharge lamps to obtai...

In order to rapidly identify the source of water inrush in coal mine, and provide the theoretical basis for mine water damage prevention and control, fuzzy comprehensive evaluation model was established. The F statistics of water samples was normalized as the weight of fuzzy comprehensive evaluation for determining the source of water inrush in coal mine. The determination result of F statistic...

Knowledge about the magnetic quantities in a magnetic circuit is always of great interest. On the one hand, this information is needed for the simulation of a transformer. On the other hand, parameter studies are more reliable, if the magnetic quantities are derived from a well established model. One possibility to model the 3-phase transformer is by using a magnetic equivalent circuit (MEC). T...

In the last years controlled switching became an effective method to reduce switching transients which is documented by several publications – especially of CIGRE. Controlled switching is most commonly used for switching capacitor banks. Even though uncontrolled energisation of power transformers can lead to very high inrush current transients whose maximum values can exceed many times the rate...

Theoretically, controlled switching taking into account the residual flux is able to fully eliminate inrush currents. Due to non-idealities in the field (closing time scatter, residual flux measurement uncertainty) that significantly affect the performance of controlled switching, inrush currents of 1.0 pu must be tolerated. To calculate the maximum acceptable tolerances of both nonidealities i...

Due to an unfortunate oversight the acknowledgement has been given erroneously. It should read.

This paper presents the use of Artificial Neural Networks (ANN) as a pattern classifier for the combined differential protection of generator-transformer unit with an aim to build a backup protection system to improve the overall reliability of the system. The proposed neural network model is trained and tested with an efficient Resilient Back propagation (RPROP) algorithm and Genetic Algorithm...