21-05-2012, 03:10 PM
ISLANDING
ISLANDING SEMINAR.ppt (Size: 326.5 KB / Downloads: 47)
What is islanding?
Normally all Power generators are interconnected to form a network called ‘GRID’.
Some times it so happens for a generator to come out of grid, either due to disturbance in grid or due to some other internal reasons. When generator gets disconnected from the grid it is ‘ISLANDED’.
The advantages of Islanding in our network:
Unit tripping can be avoided
Tripping of major critical loads in steel plant & JPOCL can be avoided
Generation loss can be avoided
Oil consumption can be reduced or avoided
If other unit got tripped, it can be restored fast
Islanded unit can be connected back to grid much faster, once grid disturbance is cleared.`
Scenario generation & loads before Islanding:
GT-1, CPP-2, ST-1, ST-2, T-1, T-2,T-3,T-4, T-5, T-7, T-8 & T-9 will be connected to BUS-2 (Islanding Bus)
GT-2, T-6, T-10, L-1, L-2, ICT-1, ST-3 & ST-4 are connected to BUS-1
CPP-1 will be selected either in mode-1 or mode-2 depending upon their gas availability. Mode-1 will trip CPP-1 in case of islanding and Mode-2 will bring it to house load.
CPP-2 has been chosen to put in parallel islanding along with one of our unit. Depending upon the CPP-2 generation and BF-3 status, following modes has been incorporated
In case CPP-2 generation is less or it nor required in islanding scheme a face plate is provided in DCS to enable or disable CPP-2 tripping in line loading logic.
Consequences Islanding:
In case of islanding & bus coupler open, a hard wired logic provided to trip both the 220KV lines. In this condition if ICT is healthy, then U#2 will survive else it will trip. L1 & L2 breakers open to non-islanding unit trip is removed