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A new under‐voltage load shedding scheme for islanded distribution system based on voltage stability indices
Author(s) -
Yusof Nurul Aisyah,
Mohd Rosli Hazwani,
Mokhlis Hazlie,
Karimi Mazaher,
Selvaraj Jeyraj,
Sapari Norazliani Md
Publication year - 2017
Publication title -
ieej transactions on electrical and electronic engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.254
H-Index - 30
eISSN - 1931-4981
pISSN - 1931-4973
DOI - 10.1002/tee.22452
Subject(s) - load shedding , control theory (sociology) , voltage , electric power system , photovoltaic system , transmission system , voltage regulation , grid , stability (learning theory) , distributed generation , transmission (telecommunications) , engineering , power (physics) , computer science , electrical engineering , mathematics , renewable energy , control (management) , physics , geometry , quantum mechanics , artificial intelligence , machine learning
Under‐voltage load shedding (UVLS) is an important technique to maintain the voltage stability and frequency of a power system network. UVLS has been applied widely in transmission systems to avoid system blackouts. However, with increasing penetration of distributed generation such as photovoltaic (PV) systems, the application of UVLS becomes important for islanded distribution systems. Under this condition, the network does not have a frequency reference as when it is connected to the grid. In this condition, when the load demand exceeds the PV capacity, UVLS is the only option to stabilize the system by shedding the load based on the changes of the voltage magnitude. In this work, a new UVLS scheme based on voltage stability indices is proposed. Four voltage stability indices are used as indicators for load shedding. Based on the stability indices, the loads that have the highest tendency of voltage collapse shall be the first ones to be shed. The proposed scheme is tested on a practical distribution network energized by a grid, a mini hydro generator, and a PV system. The test results on various scenarios prove that the proposed method is able to restore the system stability. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.