ANNUAL REPORT 2011-12 - State Load Despatch Centre (SLDC)

Annual Report 2011-12
D. Transferring of 132 KV system load to 220 KV system
The Gujarat system is now having cheaper generation from Adani-Mundra, Essar-
Vadinar and Tata UMPP-Mundra power plants. Also, the minimum contribution from
RE sources (Wind + Solar) is around 600 MW which, being green power has to be
absorbed in the system. Overall frequency trend has improved. The generation
available with Sikka TPS (STPS) and gas based power stations is costlier and DISCOMs
are not giving schedule. So, the generation from STPS and Dhuvaran Gas Based (DGB)
power station is scheduled only in case of extreme contingency. Also, GIPCL unit is
kept under reserve shut down (RSD) so many times looking to merit order despatch.
As the STPS, DGB and GIPCL units are connected to 132 KV system, non-availability of
these units cause substantial loading on 220/132 KV ICTs at Rajkot, Limdi, Karamsad,
Asoj and Jambuva.
Considering above, it is very important to continuously monitor the 132 KV system
and ensure that no part of the network becomes vulnerable and reliability is not put
at risk. Therefore, it is required to transfer most of the loads of 132 KV system to
nearest 220 KV system wherever feasible so as to relieve the loading on 132 KV
system.
E. PGVCL catering more than 3000 MW load without RE generation support:
The Gujarat system is catering maximum energy from last week of September to end
of November without RE generation support to the grid. At the same time, PGVCL is
catering maximum load due to high potential rise in AG demand. In such conditions,
many important lines and ICTs at major substations are loaded to about 70 to 80% of
the rated capacity resulting in denial of outages for such lines and ICTs even for a day
or two.
F. Network complexity in South Gujarat Pocket:
The units of GPEC, Essar-Hazira, Kawas are kept under reserve shut down or running
on technical minimum for long time looking to merit order despatch. As a result, most
of the time, the loading on 220 KV D/C Ukai – Mota, 220 KV S/C Kawas – Icchapore,
220 KV D/C Jhanor – Haldarwa, and the EHV lines connected to 220 KV Vav and 220 KV
Vapi S/S remain on higher side resulting in denial of outages of lines even for a few
hours.
State Load Despatch Centre
Gujarat Energy Transmission Corporation Limited
43