Optimal Placement of Unified Power Flow Controllers to Improve Dynamic Voltage Stability Using Power System Variable Based Voltage Stability Indices Research Authors FADI ALBATSH, Saad Mekhilef, Shameem Ahmad, Hazlie Mokhlis and M. A. Hassan Research Journal Plos One Research Member Mohsen AbdelNaeim Hassan Mohamed Research Rank 1 Research Vol Vol 10 No 4. Research Year 2015