PRESENT CONDITIONS

FREQUENCY DURATION CURVE , , & < & < & Above MaxMinAvgFVI

FREQUENCY SPECTRUM OF SOUTHERN REGION FOR PAST SIX YEARS

VOLTAGE PROFILE OF SOUTHERN REGION FOR PAST SIX YEARS

ISSUE: In general it can be seen that SR grid is shifting from low frequency/ low voltage to high frequency/high voltage regime.

HIGH VOLTAGE CONDITIONS IN SOUTHERN REGIONAL GRID

VARIATION OF MAXIMUM VOLTAGES IN SR GRID DURING NOV 2005

Issues Of Concern – High Voltage Frequent switching in/out of Lines –Resulting wear and tear of equipments Continuous High Voltage –Resulting damage to the equipments Network Redundancy is lost with opening of EHV lines –causing Security concerns Opening of EHV lines causes increase in system losses –Commercial losses

Actions Taken TAKING OUT THE LINE AND CONVERTING LINE REACTOR TO BUS REACTOR MVAR ABSORPTION BY GENERATING UNITS TRANSFORMER TAP CHANGES MANY ICT TAPS WERE CHANGED ON 400/220 ICT’s GT TAP CHANGES OPENING UP OF LIGHTLY LOADED REDUNDANT TIE LINES UTILISATION OF HYBRID AC/DC NETWORK DIVERSION OF TALCHER STAGE 2 POWER THROUGH GAJUWAKA

Desired Actions ABSORPTION OF VARS BY ALL THE OPERATING UNITS WITHIN THEIR CAPABILITY CURVES OPENING OF 220 KV AND BELOW LEVEL LIGHTLY LOADED LINES IN SATES GENERATORS ON SYNCH CONDENSOR MODE TO CARRY OUT DETAILED STUDIES TO FIND OUT REQUIREMENT OF ADDITIONAL REACTORS AT SUITABLE LOCATIONS

HIGH FREQUENCY CONDITIONS IN SOUTHERN REGIONAL GRID

FREQUENCY PROFILE DURING THE MONTHS SEPTEMBER, OCTOBER, NOVEMBER 2005 Cont..

Issues Of Concern – High Frequency Wastage of Resources Grid Insecurity High Frequency also Causes High Voltage Damage to the Equipments Cont..

ACTIONS TAKEN TO ARREST HIGH FREQUENCY: Reservoir based hydro backing/closing Liquid Fuel Stations backing/closing down Inter Regional Export under UI Thermal Stations backing/Closing down Exports under Short Term Open Access (STOA ) Cont..

TARIFF RELATED SOLUTION: RATIONALISATION OF UI PRICE CURVE SLOPES

IN SR 16000MW OF THERMALS OUT OF MW (87%) HAS VARIABLE COST THAT FALLS IN THE RANGE OF 60PAISE TO 300 PAISE

THIS UI CURVE WAS IN EFFECT FROM 01JAN 03 TO 31 MAR 04 THIS UI CURVE WAS IN EFFECT FROM 01 APR 04 TO 30 SEP 04

UNITS WITH A VARIBLE COST OF 90 PAISE WOULD NOT REDUCE TILL FREQUENCY RISES ABOVE 50.2 HZ UNITS WITH A VARIBLE COST OF 90 PAISE WOULD NOW HAVE TO REDUCE AT 50.00HZ ITSELF UI_PRICE Vs FREQUENCY:- THE EFFECT OF PRICE VECTOR ON GENERATION FREQUENCY IN HZ UI PRICE IN PAISA/UNIT IN SR 16000MW OF THERMALS OUT OF MW (87%) HAS VARIABLE COST THAT FALLS IN THE RANGE OF 60PAISE TO 300 paise UI CURVE IN FORCE SINCE 01 OCT 04 SHOW TABLE HIDE TABLE HIDE GRAPH SHOW GRAPH KNEE POINT CHANGED FROM 49.8 TO 50 HZ SLOPE OF HIGH FREQUENCY BAND CHANGED FROM 30ps/0.1 HZ TO 18ps/0.1 HZ SHOW CHANGES

Furthur Rationlisation of UI curve can address low frequency problem also.

SHOW TABLE HIDE TABLE ESC TO EXIT