Detailed vision of 2012 related to transmission sector

Detailed vision of 2012 related to transmission sector

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The Investments in and growth of Transmission, sub-Transmission and Distribution Systems have not matched the increase in generating capacity. Consequently, there are constraints of power evacuation from generating sations. The problem is severe in the eastern region, where surplus capacity is idling due to lack of absorption network and evacuation facilities. The power sector development demands a thrust on Transmission sector and the following blueprint is envisaged for the sector.

Formation of National Grid
Before the beginning of the planning era in 1951, the electricity supply industry in the country consisted of generating stations supplying power to loads in their immediate vicinity. With a view to promote reliability of power supply and achieving operating economies, interconnections of individuals systems was down leading first to the formation of State grids. The uneven geographical distributon of exploitable energy resources (coal and hydro potential in the country) necessitated large scale transportation of coal across the State boundaris. A decision was taken in the early sixties to create regional electricity grids as basic units for power planning and operations of the electric power system. In the seventies, the regional grids were in position and advantages of sharing generating capacity between the State, and the inter-connected operation were being obtained. In the eighties, with the commissioning of the Regional power stations by Central sector Generating Companies (NTPC, NHPC) and construction of EHV transmission lines by them transcending state boundaries, the development of regional grids was further accelerated. This has necessitated the formation of a National Power Grid to fulfill the following objectives:

  • Enable transfer to power from power surplus regions to deficit regions
  • Enable optimal development and utilisation of coal and hydro resources, in the overall interest of the nation.
  • Improve economy, reliability and quality of power supply.

Towards the objective of formation of National Grid, a number of inter-regional schemes have been planned for phased development. The brief status including interregional links under operation, approved schemes and future programme is presented ahead:

With the help of the above links, transfer of power among the regions, especially from the power surplus Eastern Region, has enhanced significantly, as can be seen from the chart below:

Inter-regional links under Operation

Energy Transferred Among Regions (Million Units)

New Approved Schemes
In order to further strengthen the interconnection between regions, some more schemes have been approved which are under different stages of implementation and are expected to be commissioned by 2003.

Additional inter-regional Schemes by 2003

Name of the link Regions Interconnected Capacity (MW)
Talcher-Kolar HVDC bipole East and South 2000
Rourkela-Raipur 400kV D/c East and West 1000
Total 3000

Future Programme
Looking into the future demand and availability of generation resources, a Perspective Transmission Plan has been drawn up indicating the major inter-regional transmission highways to be developed by 2011-12. This will ultimately lead to the formation of a strong National Grid. These highways are proposed to be established in phases matching with the requirement of inter-regional power transfer.

As per the envisaged programme, cumulative capacity of the inter-regional links will be enhanced as shown in the graph.

Evacuation of surplus power from Eastern Region
Eastern Region at present is having substantial energy surplus, as load growth has to been commensurate with the generation capacity addition, leading to non-utilisation of available capacities. The total installed capacity in the Eastern region is of the order of 15,000 MW (out of which NTPC contributes 3900MW) whereas the peak load is around 6500-7500 MW and off-peak load is 4000-4500 MW.

While the formation of National Grid is an ultimate solution to remove inter-regional imbalance, the following schemes have been completed on priority basis to facilitate power transfer from surplus Eastern Region to other deficit Regions,

  • 220 kV 3rd Ckt Korba-Budhipadar connecting ER & WR
  • Jeypore-Gazuwaka HVDC Bipole between ER & SR
  • 220 kV S/c Balimela-Upper Sileru between ER & SR
  • 400 kV D/c Bongaigoan-Malda between ER & NER
  • 220 kV D/c Birpara-Salakati between ER & NER
  • 220 kV S/c Dehri-Mughalsarai between NR & ER
  • 400 kV Sasaram-Sarnath-Allahabad line between NR & ER

With the above concerted efforts, energy exchange from Eastern Region has increased to the turn of about 6,790 MUs in 2000-2001 as against 5500 MUs in 1999-2000, registering a growth of more than 23%. However total transfer of only 1100 MW is posssible currently. Inter-regional links to increase the transfer to 4400 MW in short run involving an investments of Rs.17,600 crores are proposed.

A task force under the Chairmanship of Special Secretary (Power) has been constituted by Ministry of Power to formulate a short-term action plan for evacuation of surplus power from Eastern Region.

Monitoring of grid discipline and grid issues
Grid discipline is a pre-requisite for maintenance of primary grid parameters namely frequency and voltage within permissible limits for safe, secure and stable operation of the grid. However in India, the operating frequency goes beyond the permissible range of 49-50.5 Hz. mainly due to:

  • Mismatch in generation and demand.
  • Due to chronic power shortages, there is a tendency among state utilities to overdraw from the grid during peak hours.
  • Predominance of thermal/base load stations and inadequate peaking capacity (hydro/Gas Turbines) limiting the flexibility of generation control as per load pattern of the grid.

Lack of grid discipine leads to critical situations of the kind, which happened on the 2nd of January 2001 in the Northern region, when the entire grid failed. A failure of this proportion not only causes severe stress on the power plant equipment and reduces its life, it also has a cascading effect on the industries and the people. It adds up to huge economic losses and causes immense damage to the country’s image. After the grid failure in January 2001, at the instance of the Minister of Power, the Chairman, CEA conducted an inquiry and submitted its report. Follow-up action on the report is being taken on priority. The following measures have already been taken.

  • Modification and modernisation of Panipat 400 KVA substation
  • In-principle approval of CEA given to (i) series compensation for Panki-Muradnagar, (ii) providing inter-connection between 400 KVA substations of POWERGRID and UPPCL at Agra, and (iii) preponing of Allahabad-Mainpuri-Ballabgardh 400 KV double circuit line.
  • All States have been advised to observe strict grid frequency discipline, promptly carry out the instructions of RLDC, ensure free governor operation of their power plants and expedite capacitor installation programme.

As a result of these measures, there has been substantial improvement in grid frequency. However the situation is being closely monitored to prevent its recurrence.

Encouraging FDI in Transmission
Out of the Rs.8,00,000 crores required for doubling the power capacity to 2,00,000 MW by the year 2012, about Rs.2,00,000 crores would be required for the associated transmission system including creation of a National Grid. Out of this, an investment of about Rs.70,000 crores would be required in Central Sector Transmission Systems alone. POWERGRID is expected to mobilise an investment of Rs.41,000 crores from its own resources. The balance requirement of Rs.29,000 Crores is proposed to be mobilised through private investments.

Considering the scale of investment and the volume of expansion required, attracting large private investment in transmission is essential. The Government of India amended Indian Electricity Act and Electricity Supply Act in 1998, to enable private sector participation in transmission sector. In January 2000, the Ministry of Power has issued detailed guidelines for private sector participation in transmission. The Guidelines envisage two routes for inviting private sector participation. One route is through joint Venture of POWERGRID and private investor. The other route called IPTC (Independent Power Transmission Corporation) shall facilitate private investor including investors coming through FDI to invest 100% by themselves.

Preparation of Manual on Disaster Management
Power is an essential service and it is one of the first to be affected by natural disasters like the earthquake in Gujarat in January, 2001 and the cyclone in Orissa in October, 1999. it is, therefore, necessary to have a clear-cut action plan ready for managing major breakdown of essential power supply posing wide-spread and protracted problems. Ministry of Power has directed all power sector utilities and State Electricity Boards to prepare contingency plans to meet situations arising out of breakdown of machinery and equipment and disruption of power system due to any reasons including natural calmities. Such action plans have already been drawn by a number of State Electricity Boards and Central Power Sector Undertakings such NTPC, NHPC, PGCIL, BBMB.