Power Grid Corporation of India Ltd (PGCIL), in a recent stock exchange filing, said that Pole-2 and some more components of the Raigarh-Pugalur HVDC link have started commercial operations.
PGCIL elaborated that the following assets related to the ±800kV Raigarh-Pugalur link traversing from Chhattisgarh to Kerala have started commercial operations effective March 9, 2021:
- ± 800kV 1,500 mw (Pole-II) HVDC terminal each at Raigarh (HVDC Station) and Pugalur (HVDC Station). This forms part of the Raigarh-Pugalur HVDC system with a transmission capacity of 6,000 mw.
- ±320kV VSC-based 2,000 mw Pugalur (HVDC) – North Trichur HVDC (Kerala) HVDC link (Part of this link, in Kerala portion, is implemented as underground cable) along with ±320kV 1,000 mw (Mono Pole-II) HVDC terminal each at Pugalur (HVDC Station) and North Trichur (HVDC Station) [Read separate story.]
- LILO of North Trichur-Cochin 400KV (Quad) D/C line at North Trichur HVDC station along with associated bays and equipment (GIS) at North Trichur HVDC station.
The associated bays and equipment related to #3 are:
- 2 x 315 MVA 400/220/33kV three-phase auto transformers along with its associated bays and equipment (GIS) at North Trichur HVDC station; and
- Two additional 220KV GIS line bays at North Trichur HVDC for implementation of 220kV feeder of Kerala.
Pole-1 of the Raigarh-Pugalur HVDC link started commercial operations on September 6, 2020. (Read more)
Project Background
The Raigarh-Pugalur bipolar link with a transfer capacity of 6,000 mw, will traverse around 1,750 km from Chhattisgarh to Tamil Nadu, passing through Maharashtra, Andhra Pradesh and Telangana, en route.
The 800kV bipolar Raigarh-Pugalur HVDC line will help India’s southern region importing power from the northern region. In view of the long-distance, it was decided to go in for HVDC technology.
One component of the project is a 320kV HVDC line spanning 153 km and the VSC terminal. It may be noted that the 320kV HVDC line discussed above will connect Pugalur in Tamil Nadu to North Trichur in Kerala, and will have a transfer capacity of 2,000 mw. Because of severe right-of-way constraints in Kerala, it was decided to go in for VSC technology so that power could ultimately be transferred to Kerala.
It is very interesting to note that in this 320kV link between Tamil Nadu and Kerala, there are overhead lines up to the Kerala territory. Within Kerala, wherever RoW constraints were encountered, PGCIL has laid underground EHV cables. Of the 153 km of total length, underground cables accounted for some 27 km (all in Kerala).
Apart from HVDC, VSC technology and underground EHV cables were innovations that marked a departure from conventional technology for interregional lines.
(Featured photograph for illustration only)
