Small signal stability and coherency analysis of northern regional power grid of India

This paper presented results on 'small signal stability' and 'coherency' analysis of Northern Regional Power Grid (NRPG) system of India. Analysis is conducted by using modelling data of NRPG in Power System Toolbox (PST). The study based on modelling data of NRPG system is presented first time in this article. Conventional approaches, “eigenvalue analysis” and “slow & tight coherency analysis” are used for 'small signal stability' and 'coherency' analysis respectively. Mode shape of inter-area mode, local mode and participation factors for inter-area mode are shown. 'Slow coherency' method gives nine coherent areas by using nine slowest modes whereas 'tight coherency' method gives sixteen coherent areas for the same number of slowest modes.