Feasibility study of using synchronized phasor measurements for generator dropping controls in the Colstrip System

This paper presents a feasibility study of using synchronized phasor measurements for improving selectivity of the generator dropping controls at the Colstrip power plant-acceleration trend relay (ATR). The purpose of this study is to evaluate the usefulness of phasor information for the Colstrip stability controls. The ATR performance during the August 10th 1996 Western Systems Coordinating Council system disturbance event is analyzed, and benefits of using relative phase angles for generator dropping controls are demonstrated. The EMTP studies are done to evaluate and compare performance of the ATR and PMU transducers during large transient events in the Colstrip system.