IN ADDITION OF UI RATE CORROSPONDING TO FREQUENCY OF 49 IN ADDITION OF UI RATE CORROSPONDING TO FREQUENCY OF 49.2 HZ AN ADDITIONAL UNSCHEDULED INTERCHANGE CHARGE AT THE RATE EQUIVALENT TO 40 % OF THE UI RATE CORRESPONDING TO FREQ. OF 49.2 HZ SHALL BE APPLICABLE FOR OVER-DRAWL OR UNDER-INJECTION OF ELECTRICITY FOR EACH TIMEBLOCK WHEN GRID FREQ IS BELOW 49.2 HZ.

Transmission and Distribution Network In India the Power and distribution system is a three tier system comprising of distribution network, state grids and regional grids. The Distribution network are owned by Distribution licensees and the state grids are primarily owned and operated by respective state utilities .In order to facilitate the transmission of power among neighboring states, state grids are interconnected to form a regional grids. Most of the Inter-state-transmission links are owned and operated by PGCIL . PGCIL is working towards achieving its mission of “Establishment and operation of Regional and National power Grids to facilitate transfer of power within and across the regions with reliability, security and economy, on sound commercial principles”.

Requiring right of way (ROW) for constructing transmission lines is becoming difficult especially in eco-sensitive areas like North-Eastern Region, Chicken neck area, hilly areas in Jammu &Kashmir and Himachal Pradesh. At the same time these areas are also endowed with major hydropower potential of the country. This necessitates creation of “Transmission Super Highways” so that constraints in ROW do not cause bottleneck in harnessing generating resources. Inter- connection of these highways from different part of the country would ultimately dead to formation of a high capacity “National power Grid”

Since there was wide variation in electrical parameters in the Regional grids, primary HVDC interconnections were established between regions to achieve the interregional power transfer capacity of 5000MW. Inter-regional connectivity to be established with hybrid system consisting of high capacity UHV & EHV AC(765kv&400kv)and HVDC links. Once it is completed, it will take the form of National Power Grid which will help not only enable to disperse power from Mega sized generation projects but also to enable transfer of bulk power from one part of the country to another in different operation scenario

Links are: Talchar-II HVDC Bipole—2000 MW Raipur-Rourkela D/C 400KV AC Line Augmentation of GazuwakaHVDC (5000MW)back to back link and Tala transmission system. Interregional transfer capacity of 16200 MW is available as on date.