Piotr Łukaszewski
supervisor: Łukasz Nogal
Rapid removal of faults reduces damage to devices and reduces their negative impact on the quality of electrical power. Hence, the development of fast and accurate protection algorithms and fault locators is crucial both from an economic and a technical point of view.
The conventional approach to fault detection is based on the analysis of currents and voltages at the fundamental frequency of the grid. For this reason, algorithms based on these values require a signal analysis over a long period of time to be sure that the short has actually occurred. A more modern approach is based on the analysis of traveling waves. This type of protection is called "ultrafast" because of its greater speed. The developed method belongs to the "ultrafast" branch of protection algorithms.
The method uses travelling waves in the phase voltage signal. Measurement takes place in a substation with the use of voltage sensors - increasingly popular measuring devices used as a substitute for voltage transformers. The sensors are characterized by a more precise transformation of the signal. The method utilizes short-time matrix pencil method to detect the waves and measure their amplitudes. Due to the fact that the voltage values are taken into account, it is possible to easily estimate the shape of the expected fault wave and to classify the type of it.