Tamil Nadu, AP, Maharashtra, MP get new transmission schemes
The National Committee on Transmission (NCT) has approved four major transmission schemes covering Tamil Nadu, Andhra Pradesh, Maharashtra and Madhya Pradesh, aimed at integrating additional renewable energy capacity and strengthening networks facing rising power flows and system constraints.
The approvals cover transmission infrastructure for the Karur and Kadapa-II renewable energy zones, evacuation and downstream network expansion at Solapur, and a common system for the 2×800 MW Gadarwara-II thermal project and additional renewable capacity at Mandsaur. The schemes will largely be implemented through the Tariff-Based Competitive Bidding (TBCB) route, with PFC Consulting Limited (PFCCL) acting as Bid Process Coordinator (BPC) for most projects.
Karur strengthening
The NCT approved the “Transmission System Strengthening at Karur PS for Integration of RE Generation Capacity” in Tamil Nadu at an estimated cost of Rs 634 crore.
The scheme is intended to accommodate an additional 687 MW of renewable generation at the Karur Renewable Energy Zone (REZ), over and above 1,489 MW already connected, while addressing loading constraints on the existing network.
The scope includes a second 400 kV double-circuit (Quad) line of around 15 km between Karur Pooling Station (PS) and Pugalur High Voltage Direct Current (HVDC), along with another 400 kV double-circuit line of around 36 km between Karur PS and the existing Pugalur substation. Associated Gas Insulated Switchgear (GIS) line bays will be developed at the Pugalur substations.
The scheme also provides for augmentation through two 500 MVA, 400/230 kV Inter-Connecting Transformers (ICTs), designated as the fifth and sixth units, at Karur PS.
The additional infrastructure is intended to relieve overloading of existing corridors under N-1 contingency conditions. It will also support enhancement of the reverse power transfer capability of the Raigarh-Pugalur HVDC link from 3,000 MW to 6,000 MW.
The project has an implementation timeframe of 30 months.
Kadapa-II integration
In Andhra Pradesh, the committee approved the “Transmission System for Integration of Kadapa-II REZ (Phase-I)” at an estimated cost of Rs 3,673 crore.
The scheme is being planned against significant connectivity interest in the Kadapa region. Applications aggregating 6,322 MW have already been received, including a 600 MW Pumped Storage Project (PSP) and a new application for a 2,250 MW PSP.
The project will establish Kadapa-II PS with 3×1,500 MVA of 765/400 kV transformation capacity and 7×500 MVA of 400/220 kV capacity, along with 330 MVAr bus reactors.
A 226 km 765 kV double-circuit transmission line will connect Kadapa-II to Thiruvalam, supported by 330 MVAr switchable line reactors. A 300 MVAr Static Synchronous Compensator (STATCOM) will also be installed at Kadapa-II PS to provide voltage support.
During deliberations, the NCT Chairperson directed that Battery Energy Storage Systems (BESS) should not be considered where hybrid applications comprising solar and PSP are received, highlighting the contribution of PSP to grid inertia and stability.
The Kadapa-II Phase-I transmission system is scheduled for implementation within 36 months.
Solapur expansion
The NCT also approved the “Transmission System for Evacuation of Power from RE Projects in Solapur SEZ (Phase-II: 2 GW) and Network Expansion Scheme to Enable Drawl of Power from Solapur PS” in Maharashtra. The scheme has an estimated cost of Rs 2,295 crore and has been divided into two parts with separate implementation schedules.
Part A, estimated at Rs 196 crore, focuses on strengthening the downstream network connected to Solapur PS. It includes two additional 500 MVA, 400/220 kV ICTs, designated as the fifth and sixth units, along with six 220 kV line bays on the new Bus Section-2 for the Maharashtra State Electricity Transmission Company Limited (MSETCL) network. This portion is scheduled for completion within 30 months.
Part B, estimated at Rs 2,099 crore, is focused on evacuation of 2 GW of renewable energy capacity. It includes creation of a new 400 kV Bus Section-2 and 220 kV Bus Section-3 at Solapur PS, along with three additional 500 MVA, 400/220 kV ICTs, designated as the eighth, ninth and tenth units.
The transmission component includes a 240 km 400 kV double-circuit line between Solapur PS and Jejuri (MSETCL), followed by a 20 km 400 kV double-circuit connection between Jejuri and Pune-III. The system will also include 125 MVAr bus reactors and 63 MVAr switchable line reactors.
Given severe Right-of-Way constraints, MSETCL suggested constructing the Solapur PS-Pune-III line and subsequently carrying out loop-in loop-out (LILO) at Jejuri using multi-circuit towers.
Part B has an implementation period of 36 months. Apart from renewable evacuation, the broader scheme will strengthen Maharashtra’s intra-state network and support the recently awarded Wagdari Transmission Limited project.
Gadarwara and Mandsaur
In Madhya Pradesh, the committee approved the “Common Transmission System Augmentation for Evacuation of Power from 2×800 MW Gadarwara-II TPS and an Additional 1500 MW RE Power at Mandsaur PS” at an estimated cost of Rs 3,573 crore.
The transmission system has been divided into two parts to align infrastructure development with the commissioning schedule of NTPC Limited’s Gadarwara-II Thermal Power Station (TPS).
Part A, estimated at Rs 3,201 crore with an implementation period of 36 months, includes augmentation of Mandsaur PS with two 1,500 MVA, 765/400 kV ICTs, designated as the fifth and sixth units, and three 500 MVA, 400/220 kV ICTs, designated as the eighth, ninth and tenth units.
A ±400 MVAr STATCOM will also be installed at Mandsaur PS to provide dynamic reactive power support.
The scheme further includes establishment of a new 765 kV Gadarwara substation with four line bays and bus reactors. The associated 765 kV network comprises the approximately 225 km Kurawar-Gadarwara single-circuit line, approximately 50 km Kurawar-Bhopal single-circuit line and approximately 175 km Bhopal-Gadarwara single-circuit line.
The scope also provides for 240 MVAr switchable line reactors at the Gadarwara and Bhopal ends.
Part B, estimated at Rs 372 crore, is scheduled for completion by March 31, 2031. It will establish the 400 kV level at the Gadarwara substation with two 1,500 MVA, 765/400 kV ICTs. It also includes 400 kV line bays at Gadarwara and Seoni (PG) substations for downstream connections to Madhya Pradesh Power Transmission Company Limited (MPPTCL).
The common transmission system is intended to evacuate power from the 2×800 MW Gadarwara-II project and accommodate an additional 1,500 MW of renewable generation at Mandsaur PS. It will also address loading on the existing Gadarwara-Jabalpur and Gadarwara-Warora corridors and help maintain fault levels at critical substations within permissible limits.
The featured photograph is for representation only.
