Inter-regional Transfer Capacity

Indian power network is demarcated into five regions (North, East, West, South and North-East) and any power flow from one region to another is restricted by the inter-regional corridor transfer capacity. The graphs below provide information related to transfer capability and transmission reliability margin for different inter-regional corridors.

Inter-regional Transfer Capacity

Intra-regional Transfer Capacity

Indian power network is demarcated into five regions (North, East, West, South and North-East) and there is power flow from one state to another state within each region, with limitation in terms of transfer capacity within a region. The graph below shows the transfer capacity for intra-regional corridors and at the state level, published by POSOCO.

Intra-regional Transfer Capacity

Congestion

The Indian power network is demarcated into five regions (North, East, West, South and North-East). The power flow within a region and across regions is limited by the transfer capacity. At certain times, there is a possibility that the demand for power flow is more than the transfer capacity, resulting in congestion within the transmission system. For smoother functioning and grid management, POSOCO provides real-time import-export transmission flows for each region and corridor here
In addition to this, POSOCO also issues congestion warning notices at different time and can be accessed here.

Congestion-warning-notice-on-SR-import-17.11.2018 
Congestion Warning Notice WR-NR & NR Import 22.06.2018 
Congestion Warning Notice WR-NR & NR Import 23.06.2018 
CONGESTION-WARNING-NOTICE-25.03.2019 
Congestion-Warning-for-NR-Import-on-Date-15.08.2018. 
Congestion-warning-for-SR-Import-date-16.10.2018. 
CONGESTION-WARNING-NOTICE-31032019_1647hrs 
ATC_NLDC_Apr'17_Rev19 
Congestion-Warning-for-NR-Import-on-Date-17.08.2018 

Curtailment

The Indian Electricity Grid Code (IEGC) provides must run status to solar and wind power projects. Their curtailment is only allowed to ensure grid security, for example in situations of transmission constraints.

A petition was filed before APTEL regarding the backing down instructions given by SLDC to solar generators in the state of Tamil Nadu. During this process, APTEL directed POSOCO to conduct a third-party assessment on the issue raised by the appellant. The summary on APTEL order and POSOCO report in this regard can be found here.

POSOCO Report to APTEL on RE curtailment
APTEL Judgement on RE curtailment

State Transmission Performance

While there are various parameters against which the performance of a transmission network in a state can be assessed, we have covered two important parameters which are Transmission line losses and Transmission network availability. The graph below shows the performance for 11 states with these two parameters.

State Transmission Performance

GNA allocation by CTU

Central Transmission Utility (CTU) has allocated GNA to state licensees based on the provisions of GNA Regulations, 2022. The graph below presents the GNA allocated to each licensee and compares the same with the maximum demand for the state in 2021-22.

The summary and relevant documents of GNA regulations can be accessed here.

GNA allocation by CTU