Manual on Planning Criteria
The Manual on Planning Criteria is prepared by CEA and covers the transmission network planning philosophy, the information required from various entities, permissible limits, reliability criteria, broad scope of system studies, modelling and analysis etc. and gives guidelines for transmission planning. The manual was initially prepared in 1985, revised in 1994 and again in 2013. A completely revised manual was released in 2023, the summary of which can be found below.
CEA Manual on Transmission Planning Criteria 2023
Effective from
1st April, 2023 (for all new transmission systems planned thereafter)
Planning Philosophy
1. The principle for planning of the ISTS shall be to ensure that it is available as per the requirements of the States and the generators, as reflected by their General Network Access (GNA) requests. As far as possible, the transmission system shall be planned and developed matching with growth of generation and load and care shall be taken that there is no wasteful investment.
2. The transmission customers as well as utilities shall give their network access requirement well in advance considering time required for implementation of the transmission assets. Transmission customers are also required to provde a reasonable basis for their transmission requirement such as size and completion schedule of their generation facility, demand and their commitment to bear transmission service charges.
3. In case of highly constrained areas like congested urban / semi-urban area, very difficult terrain (including hilly) etc., the transmission corridor may be planned by taking long term perspective of optimizing the right-of-way and cost.
4. The system parameters and loading of system elements shall remain within permissible limits. The adequacy of the transmission system should be tested for different probable load-generation scenarios as detailed in the manual.
5. For strengthening of the transmission network, cost, reliability, right-of way requirements, transmission losses, down time (in case of up-gradation and reconductoring options) etc. need to be studied. If need arises, addition of new transmission lines/ substations to avoid overloading of existing system including adoption of next higher voltage may be explored.
6. The planned transmission capacity would be finite and there are bound to be congestions if large quantum of electricity is sought to be transmitted in direction not previously planned.
7. Communication system for new transmission system may be planned and implemented such that the communication system is available at the time of commissioning of the transmission system.
8. Further, (N-0), (N-1), (N-1-1) contingency criteria shall be evaluated. N-1 criteria may not be applied to immediate connectivity system of RE generators with ISTS or InSTS grid. But it shall be applicable for RE projects with storage. N-1 reliability criteria may be considered for ICTs at the ISTS / STU pooling stations for renewable energy-based generation of more than 1000 MW after considering the capacity factor of renewable generating stations.
9. Also, economic analysis of planned alternatives shall be carried out, considering project cost, annual transmission charges and impact on existing total annual transmission charges.
2. The transmission customers as well as utilities shall give their network access requirement well in advance considering time required for implementation of the transmission assets. Transmission customers are also required to provde a reasonable basis for their transmission requirement such as size and completion schedule of their generation facility, demand and their commitment to bear transmission service charges.
3. In case of highly constrained areas like congested urban / semi-urban area, very difficult terrain (including hilly) etc., the transmission corridor may be planned by taking long term perspective of optimizing the right-of-way and cost.
4. The system parameters and loading of system elements shall remain within permissible limits. The adequacy of the transmission system should be tested for different probable load-generation scenarios as detailed in the manual.
5. For strengthening of the transmission network, cost, reliability, right-of way requirements, transmission losses, down time (in case of up-gradation and reconductoring options) etc. need to be studied. If need arises, addition of new transmission lines/ substations to avoid overloading of existing system including adoption of next higher voltage may be explored.
6. The planned transmission capacity would be finite and there are bound to be congestions if large quantum of electricity is sought to be transmitted in direction not previously planned.
7. Communication system for new transmission system may be planned and implemented such that the communication system is available at the time of commissioning of the transmission system.
8. Further, (N-0), (N-1), (N-1-1) contingency criteria shall be evaluated. N-1 criteria may not be applied to immediate connectivity system of RE generators with ISTS or InSTS grid. But it shall be applicable for RE projects with storage. N-1 reliability criteria may be considered for ICTs at the ISTS / STU pooling stations for renewable energy-based generation of more than 1000 MW after considering the capacity factor of renewable generating stations.
9. Also, economic analysis of planned alternatives shall be carried out, considering project cost, annual transmission charges and impact on existing total annual transmission charges.
Aspects to consider while planning
Transmission system planning shall be done considering following aspects:
a) Power system data for transmission planning modelling: Data accuracy; use of actual data
b) Time horizon for transmission planning: 3-5 years on rolling basis every year
c) Load generation scenarios: reflecting typical daily and seasonal variations in load demand and generation availability.
d) Load: Active Power, Reactive power
e) Generation dispatches and modelling: considering different generation dispatch scenarios, special are dispatches (like high agricultural load or complete closure of generating station close to a major load centre)
f) Planning margins to avoid stranded transmission assets
g) System studies for transmission planning (Power flow studies, Short circuit studies, Stability studies, ATC/ TTC calculations, Electro Magnetic Transient (EMTP) studies)
h) Inertia: Assessing system inertia to assess frequency assessment
a) Power system data for transmission planning modelling: Data accuracy; use of actual data
b) Time horizon for transmission planning: 3-5 years on rolling basis every year
c) Load generation scenarios: reflecting typical daily and seasonal variations in load demand and generation availability.
d) Load: Active Power, Reactive power
e) Generation dispatches and modelling: considering different generation dispatch scenarios, special are dispatches (like high agricultural load or complete closure of generating station close to a major load centre)
f) Planning margins to avoid stranded transmission assets
g) System studies for transmission planning (Power flow studies, Short circuit studies, Stability studies, ATC/ TTC calculations, Electro Magnetic Transient (EMTP) studies)
h) Inertia: Assessing system inertia to assess frequency assessment