Synchrophasor Initiative in India - erldc

SYNCHROPHASORS - INITIATIVE IN INDIA JUNE 20124.2 Visualization of angular separation between two nodes in the gridThe angular separation between two nodes within a synchronous system is primarily a functionof the voltage at the two nodes; Impedance between the two nodes and the power flow betweenthe nodes. Therefore the angular separation between the two nodes is sensitive to the variationin one or more of these variables. This has been illustrated with the help of plot showingvariation in angular separation between Vindhyachal/Kanpur/Dadri/Agra/Hisar/Bassi/Mogaduring the following four grid incidents:• Complete 400/220 kV Allahabad substation handling 1900 MW;• Tripping of + 500 kV Rihand-Dadri HVDC bipole carrying 1400 MW• Tripping of 400/220 kV ICTs at Greater Noida carrying 430 MW• Tripping of complete power station at Rihand STPS generating 2000 MW4.2.1 Case Study-2: Complete outage of 400/220kV AllahabadOn 14th January 2012, a bus fault on 400 kV bus at Allahabad resulted into loss of all theincoming and outgoing lines at the 400/220 kV Allahabad substation handling 1900 MW. Thispower was diverted through other parallel circuits. The consequent change in the impedanceand the voltage caused a change of 34 degrees in the angular separation between Vindhyachaland Kanpur which are located on either side of the 400/220 kV Allahabad.Figure 44: Angular difference between buses in NR during blackout at 400 kV AllahabadPOSOCO Page 57 of 143