With the offtake of 1,100 MW power from the national grid, various special protection schemes were studied and applied to enhance system stability under exigent scenarios. These schemes have helped improve system security and increased outage flexibility to perform rehabilitation works on critical 220kV interconnecting lines whilst successfully importing 1,100 MW power from National grid.
These schemes include: 1) Enhancement in Under Frequency Scheme 2) Introduction of Under Voltage load ejection scheme 3) N-1-1 contingency protection scheme on 220kV KDA-NKI-Baldia lines 4) Enhancement in existing Cross Trip Scheme in under power scenario All these schemes have been incorporated on SCADA at LDC / DRC with an audible alarm system to alert in case any of the tripping scheme is operated.
