Optimal Approach to Transmission Planning in Indian Power System

1. Transsmision Planning in India

2. Tr. Planning Practices • Indian Power System divided into five electrical Regions • Gradual shifting from Regional level planning to National level due to uneven disposition of energy resources • Planning of National Grid by interconnecting different regional grids with high capacity lines as well as development of Regional Grids

4. Tr. Planning Practices … contd • Planning process involves Policy makers, Authority, Generating agencies, Beneficiaries and Transmission utilities • Tr. Planning is not confined only to connect generation to the grid points but also take care of overall development of the grid • Tr. Planning criteria and Indian Electricity Grid Code being followed

5. Tr. Planning Procedures • Future Power demand projections carried by Central Govt. and Electric Power Survey Report published • Future generation Capacity addition programme for next 10-15 years developed by Central Govt. • Based on the above information, a long-term perspective Tr. Plan evolved

6. Tr. Planning Procedures … contd Phased development of Tr. system • Different generation utilities both at Center & State level firm up generation schemes, their time frame and beneficiaries, based on which - • State Tr. Utility (STU) plans and coordinates transmission system within states • Central Transmision Utility(CTU) evolves optimal inter-state and inter-regional transmission system in co-ordination with Authority & STUs

7. Tr. Planning Procedures … contd • The Tr. System so evolved fulfils the security standards as stipulated in the Planning criteria and Grid Code • The Tr. System so planned has adequate capacity margin for future requirements and also fits into long-term perspective plan • In addition to generation associated Tr. Schemes, system strengthening schemes are also evolved for overall development of the grid

8. Tr. Planning Procedures … contd • Tr. Schemes discussed and finalised in a common forum of Authority, generation utilities, beneficiaries, STUs and CTU

9. Hierarchy of Indian Power System

10. Tr. Planning Criteria • Tr. Capacity of a corridor evolved considering maximum power dispatch • Security standards • Withstand ‘n-1’ contingency without rescheduling of dispatch • Outage of 400kV D/c line, if such possibility is more • Application of ‘n-2’ contingency for multi line & vital Tr. corridors

11. Tr. Planning Criteria … contd • Tr. Capacity of a corridor evolved considering maximum power dispatch • Security standards • Withstand ‘n-1’ contingency without rescheduling of dispatch • Outage of 400kV D/c line, if such possibility is more • Application of ‘n-2’ contingency for multi line & vital Tr. corridors • System should remain in synchronism with outage of one single largest unit/ 5 cycles SLG fault followed by opening of line/outage of one pole of HVDC bipole

12. Tr. Planning Consideration • Bulk power transmission from generation resource confined to few pockets to far-off load centers across the regions • Conservation of Right-of-Way • Flexible for phase development • High availability/Reliability • Optimum Transmission cost

13. Technological Options • Maximum utilisation of existing transmission facilities • Application of FACTS devices – SVC, TCSC etc. • Uprating/upgrading of Tr. Lines • Conversion of AC line to HVDC line • Dynamic Thermal circuit rating • Development of new Tr. corridor • Multi-conductor line • 800kV lines/HVDC bipole • Compact line/Multi-circuit lines • High thermal rating conductors like INVAR

14. Future Transmission Plan

15. Future Transmission Plan Phase-II & III Phase – II & III

16. Growth of cumulative capacity of inter-regional links