DISTANCE PROTECTION RELAY WITH PRONY PHASOR ESTIMATION.

摘要

The present invention describes a device and a method for a microprocesor distance relay using as an alternative phasorial estimation the Prony method, for obtaining the corresponding fundamental frequency phasors of the voltage and current signals required by the distance relay. The relay comprises a higher fault-detection sensitivity by obtaining a minimum error in the value estimate of the fundamental frequency phasors required by the distance relay, thereby resulting in a reduction in the operating time in comparison with the relays using conventional digital filters. The device of the present invention can be additionally used as an alternative for offsetting measurements errors of the apparent impedance during a fault period due to the presence of frequency components of the inter-harmonic and sub-harmonic type that affect the value estimate of the fundamental frequency phasors by using conventional digital filters. The characteristic features disclosed in the present invention can be used in other protection schemes. The relay is obtained without any modifications of the hardware of a standard relay.