Incorporated in 2010, Punjab State Transmission Company Limited (PSTCL) is one of the largest state transcos in the country, with a total line length of over 12,500 ckt. km and a transformer capacity of over 38,000 MVA.
Over the last few years, PSTCL has been proactively undertaking several key initiatives towards making its grid more reliable and efficient and securing its assets. Remote substation monitoring, improved testing and diagnostics of assets, hotline maintenance, installation of high temperature low sag (HTLS) conductors, laying of optical ground wire (OPGW) to connect substations, and the use of emergency restoration systems have been some key strategies adopted by the transco to maintain network reliability and ensure high uptime, especially during the Covid pandemic.
Notably, in 2020-21, the company’s transmission losses stood at 2.5 per cent, a remarkable decline from 4.2 per cent in 2016-17. Transmission availability was maintained at 99.83 per cent for the same period. PSTCL has planned a significant capex of nearly Rs 25.9 billion for the period 2021-22 to 2025-26. The state transco is gearing up to cater to the state’s power requirement during peak summers by enhancing its import capability up to 10,000 MW by 2023.
Assets and performance
As of March 2021, the total length of PSTCL’s transmission lines stood at 12,558 ckt. km compared to 11,466 ckt. km in 2016-17. Voltage-wise, the maximum increase of nearly 4 per cent in line length, for the period between 2016-17 and 2020-21, has been at the 220 kV level. PSTCL’s transformer base across voltage levels stood at 632 as of March 2021, recording a CAGR of 1 per cent from 2016-17 to 2020-21. In 2020-21, the company’s total transformation capacity stood at 38,168 MVA compared to 33,566 MVA in 2016-17.
The transco’s substation base stood at 171 as of March 2021, an increase of about 2 per cent from 2016-17 levels. Of the total, 101 substations were at the 220 kV level, registering a CAGR of 2 per cent from 2016-17 to 2020-21, while 65 substations were at the 132 kV level, registering a negative CAGR of 1 per cent. In terms of operational performance, the transco successfully reduced its transmission losses from 4.2 per cent in 2016-17 to 2.5 per cent in 2020-21, while maintaining a high system availability of 99.83 per cent in 2020-21.
PSTCL has been actively implementing various initiatives for attaining an optimum and sustainable level of network performance parameters. Remote control operations have been implemented at some of its substations at the 220 kV level (Lalru, Dera Bassi, Kharar and Mohali-2). Another key initiative under way is the implementation of the Scheduling, Accounting, Metering and Settlement of Transactions in Electricity (SAMAST) scheme in Punjab for assessing the voltage-wise transmission losses of Punjab’s transmission network. The tender for the implementation of this scheme in Punjab was floated by PSTCL and is under evaluation. The total estimated cost of the project is Rs 244.4 million, of which the Power System Development Fund will provide funds amounting to Rs 122.2 million and the remaining Rs 122.2 million will be invested by the transco. As of now, the company has received the first instalment of funding amounting to Rs 12.2 million. Further, the company has taken measures to address the issue of overloading by undertaking works such as installation of HTLS conductors and allowing greater flow of power through same corridors. Besides, anti-fog insulators have been installed to safeguard the network from tripping or breaking down in foggy season.
To maintain transmission lines without affecting shutdowns or interruptions, hotline techniques are regularly used. Jumper tightening, disc insulator replacement and substation yard equipment repair are some hotline maintenance activities. Another key initiative has been the setting up of a first-of-its-kind oil and diagnostic testing laboratory in Ludhiana to facilitate diagnosis and testing of several parameters pertaining to direct current (DC) batteries, insulation health, power transformers, transformer oil, surge arresters and SF6 gas leakages, etc. PSTCL has also started online transformer oil reclamation to enhance system availability and provide support for financial savings with reduction in fresh oil requirement.
As per data shared by the company, PSTCL’s total revenues for 2020-21 stood at Rs 13.8 billion, as compared to Rs 13.6 billion in the previous year, recording a growth of 1.5 per cent. Notably, PSTCL had a net profit of Rs 206.6 million during this period, as compared to a net loss of Rs 335.7 million in the previous fiscal. Therefore, the company’s financial performance and liquidity profile improved remarkably, as it witnessed a CAGR of 35.5 per cent in profits and 2 per cent in revenues in the past five years. PSTCL’s operations and maintenance cost (including employee, renovation and modernisation, and administrative and general expenses) stood at Rs 5.86 billion for 2020-21, as compared to Rs 4.86 billion in 2016-17. The company had a debt-equity ratio of 1.51 for 2020-21, as compared to 1.7 in 2016-17. During 2020-21, the company incurred a capex of Rs 2.19 billion, while for 2016-17, 2017-18, 2018-19 and 2019-20, the capex was Rs 4 billion, Rs 3.51 billion, Rs 2.62 billion and Rs 2.26 billion respectively.
New technology initiatives
PSTCL is working on several new technologies and system automation techniques for reducing manpower needs and improving reliability. It has installed RHMI to control and supervise substations from remote stations. The control of the 400 kV substation at Dhuri has been shifted to the 400 kV substation at Rajpura while RHMI of another 400 kV substation is being shifted on one station. The company is also installing OPGW for connecting all substations and generation stations under a reliable communication project. Another key initiative under way is the implementation of a framework on the SAMAST scheme as recommended by the Forum of Regulators. Under this initiative, several meters are scheduled to be installed at various boundaries, generating and open access points including data concentrator units, servers, communication systems and switches. After the installation of meters along with other hardware, data of these locations/points will be available at the state load despatch centre (SLDC). The meters contain software for online scheduling of generators, reports generation, etc. Further, after implementation of SAMAST, the SLDC will commence functions such as forecasting of solar generation and scheduling, accounting and deviation settlement of all intra-state entities in line with the PSERC regulations. Another important technology initiative for the restoration of transmission corridors is the use of the emergency restoration system (ERS) in the case of fallen towers of 132/220/400 kV transmission lines.
Future plans and investments
To support the state’s power requirements during peak summers, the transco is committed to enhance its import capability up to 10,000 MW by 2023. In terms of network augmentation, three 400 kV substations at village Dhanansu near Ludhiana, Ropar, and Behman Jassa Singh and one 220 kV geographic information system (GIS) substation at Sherpur (Ludhiana) are under construction. In addition to this, augmentation of the 400/220 kV transmission system is being carried out, that is, augmentation of ICTs, replacement of aluminium conductor steel reinforced with HTLS conductors, etc.
Overall, over the next five years, that is, from 2021-22 to 2025-26, PSTCL plans to incur an annual capex of approximately Rs 5.8 billion, Rs 5.7 billion, Rs 4.5 billion, Rs 5 billion and Rs 5 billion respectively. In terms of physical network additions, PSTCL is planning to add 660 km of transmission lines between 2022-23 and 2025-26. Further, it plans to add over 6,400 MVA of substation capacity in the same period, with most of the infrastructure addition at the 220 kV level.
The way forward
PSTCL continues to play a pivotal role in maintaining strong transmission availability across Punjab. It has displayed a strong performance in reducing losses. With significant capex planned for network modernisation and capacity augmentation, and new technology initiatives for improving the state grid’s reliability and efficiency, PSTCL’s efforts are focused on meeting the future power requirements of the state as well as sustaining a strong flow of power across strategic transmission corridors.