FAST POWER SWING UNBLOCKING METHOD AND APPARATUS FOR DISTANCE PROTECTION IN POWER SYSTEM

摘要

A fast power swing unblocking method and the corresponding apparatus for a distance protection in a power system are able to ensure fast phase-segregated tripping of distance protection for faults during a power swing (3 -phase or 2-phase swing). The power swing unblocking method comprises calculating changing rates of impedances for all operating loops including phase-phase loops and phase-ground loops in the power system and identifying a fault loop based on the calculated changing rates. If a fault loop is identified, a blocked distance zone in the fault loop is unblocked and the corresponding protective relays can be excited.