Real Feeder Research Articles

High-impedance fault identification using a fuzzy reasoning system

A methodology is presented to detect high-impedance faults in radial distribution feeders by means of fuzzy logic reasoning. The proposed technique is based on the analysis of the feeder responses to impulse waves which are periodically injected at the feeder inlet. These responses are compared to standard responses which were previously stored in a database. Standard responses correspond to responses of the feeder operating in normal configurations. A supervisory system processes the information in the database and, using a fuzzy inference machine, indicates possible occurrences of abnormalities. The proposed system has been tested in a real feeder; the relevant results are presented.

A Computer Controlled VAR Compensator for Distribution Feeders

Various methods of providing VAR injection have been used to compensate the inductive current in power distribution feeders. Some were based on the optimization of the location and the rating of the compensators by minimizing the resistive losses. However, these methods were limited and their range and benefit reduced due to the approximation of the reactive load profile using a single or a limited multi-level model. This paper describes the design and the testing of a compensator that continuously. adapts to the inductive current in the feeder, ensuring a maximum reduction of the resistive power losses at all levels of inductive load for a singly located compensator. The system is based on a microprocessor controlled susceptance consisting of a fixed inductor in series with a thyristor biased by a fixed capacitor in parallel. By adjusting the firing angle of the thyristor in series with the inductor, a continuously controlled compensator is obtained. A detailed analysis of the harmonics and the means For their suppression are presented. The analysis have been verified experimentally by designing and fabricating a suitable system in which the modelled feeder is tested in a laboratory environment. Good agreement is obtained between the analysis and the experimental results. The results of the application of a simplified version of the compensator to a real feeder are also presented.

A Computer Controlled Var Compensator for Distribution Feeders

Various methods of providing VAR injection have been used to compensate the inductive current in power distribution feeders. Some were based on the optimization of the location and the rating of the compensators by minimizing the resistive losses. However, these methods were limited and their range and benefit reduced due to the approximation of the reactive load profile using a single or a limited multi-level model. This paper describes the design and the testing of a compensator that continuously. adapts to the inductive current in the feeder, ensuring a maximum reduction of the resistive power losses at all levels of inductive load for a singly located compensator. The system is based on a microprocessor controlled susceptance consisting of a fixed inductor in series with a thyristor biased by a fixed capacitor in parallel. By adjusting the firing angle of the thyristor in series with the inductor, a continuously controlled compensator is obtained. A detailed analysis of the harmonics and the means For their suppression are presented. The analysis have been verified experimentally by designing and fabricating a suitable system in which the modelled feeder is tested in a laboratory environment. Good agreement is obtained between the analysis and the experimental results. The results of the application of a simplified version of the compensator to a real feeder are also presented.