Evaluation method for determining of the probability of an asymmetrical fault location in a distribution network and a monitoring system for performing such method
TOPOLÁNEK, D. TOMAN, P. ORSÁGOVÁ, J.
The present invention relates to a method of determining probability of unsymmetrical failure occurrence points in electrical networks, where a backward chart of monitored distribution system is created, a coordination time of a failure occurrence is evaluated based on exceeding a change limit of a current negative phase-sequence component, records of change of a voltage negative phase-sequence component recorded on secondary sides of the distribution transformers (VN/NN) and records of negative phase-sequence components of currents withdrawn from feeding transformers (VVN/VN) are collected for the given coordination time of the failure occurrence. Subsequently, values of maximum change in the current and voltage negative phase-sequence components, corresponding to the instant at which the sum of all the recorded changes in the voltage negative phase-sequence components is maximal are determined. The values of the maximum change in the voltage negative phase-sequence components are converted to the primary side of a corresponding distribution transformer (VN/NN). Individual deviations of absolute values of the calculated changes of the voltage negative phase-sequence component and recorded values of the maximum change in the voltage phase-sequence component at the individual measuring nodes (MU) are then calculated from the converted maximum changes in the voltage phase-sequence components and the current phase-sequence components. Then total deviations of the absolute values of the calculated changes in voltage phase-sequence components and recorded values of the maximum changes in the voltage phase-sequence components for the individual nodes are calculated, and finally, a probability of occurrence of the asymmetry source in individual points of the monitored system is calculated.
earth fault, localization, unsymmetrical fault, negative sequence, voltage sag
Vysoké ucení technické v Brne Antonínská 548/1 60190 Brno / CZ
K využití výsledku jiným subjektem je vždy nutné nabytí licence
Poskytovatel licence na výsledek požaduje licenční poplatek