This was said to be a miracle of the 20th century since it set unprecedented records such as the length of nearly 1,500km, complex technology, and design and construction conducted concurrently in just two years.

This facility helped connect the power systems of the three regions nationwide, becoming an important turning point that reflects the Party and State’s vision about economic development and national energy security, as well as the Vietnamese people’s mettle, wisdom, and creativity in the Doi moi (Renewal) period.

After more than 10 years since the first circuit of the 500kV North-South lines was launched, the country’s electricity sector made a new milestone – putting the second circuit into use on September 23, 2005.

And now, with strong determination, the Vietnam Electricity (EVN) group and relevant units are augmenting efforts to complete Circuit 3 in the spirit of thinking big, acting bold, and daring to bear responsibility.

Miracle continues

Between 2008 and 2019, the first two 500kV lines had their capacity improved to reach 2,300MW in total, capable of transmitting more than 12 billion kWh per year.

However, many places in the southern region still experienced power cut due to transmission line overload at certain points of time. Meanwhile, some power projects there lagged behind schedule, triggering severe electricity shortage.

As electricity demand increases by over 8% annually, the output must reach 570 billion kWh during 2011 – 2030 to meet the need.

Facing that fact, the Government decided to assign EVN to invest in the Pleiku – My Phuoc – Cau Bong 500kV line project, the first stretch of the Circuit-3 500kV lines.

The Pleiku 2 500kV transformer station (Photo: VNA)

The completion and inauguration of this section in 2014 held critical importance as it guaranteed safe and stable transmission from the North to the South, along with timely and sufficient supply of electricity for people’s daily life and socio-economic development across the southern region in the dry season of 2014 and following years.

This facility helped create a prerequisite for connecting the grid in southeastern and southwestern areas, ensuring the system’s safe and economical operations in case electricity needs to be sent at a high level from region to region.

After the Pleiku – My Phuoc – Cau Bong section, in 2018, the Government tasked EVN with building the nearly-742km Vung Ang – Quang Trach – Doc Soi – Pleiku 2 section of the Circuit-3 500kV lines. Braving numerous difficulties such as flooding and the COVID-19 pandemic during the project implementation, the National Power Transmission Corporation (EVNNPT) completed this line after four years, on August 17, 2022.

The EVNNPT has gradually mastered technology to serve the management and operation of transmission lines. (Photo: VNA)

The stretch of Vung Ang – Quang Trach – Doc Soi – Pleiku 2 is crucial to improving the national power system’s 500kV transmission capacity and ensuring supply for Ha Tinh, Quang Binh, Quang Tri, Thua Thien – Hue, Quang Nam, Quang Ngai, Gia Lai, Kon Tum, Da Nang, and nearby areas in the central and Central Highlands regions.

New opportunities opened up

Following those projects, work started on a new section of the Circuit-3 500kV lines – from Pho Noi in northern Hung Yen province to Quang Trach in central Quang Binh province – in October 2023.

The new project is about 519km long and invested with some 22.35 trillion VND in total. It consists of four sub-projects, namely Quang Trach – Quynh Luu (Nghe An province), Quynh Luu – Thanh Hoa (Thanh Hoa province), Thanh Hoa – Nam Dinh 1 thermal power plant (Nam Dinh province), and Nam Dinh 1 thermal power plant – Pho Noi.

Once operational, this project will help raise the capacity of transmitting power from the central region to the North from 2,200MW to 5,000MW to guarantee supply for the northern region in the hot season.

Emphasising the significance of Circuit 3, especially to supply harmonisation among regions in the peak season, Prime Minister Pham Minh Chinh ordered ministries, sectors, and localities to keep close monitoring to ensure progress, quality, and labour safety, particularly in areas with complex terrain and amid unfavourable weather conditions, for the sake of the country, people, and national development.

Ministries, sectors, and localities were ordered to keep close monitoring to ensure progress, quality, and labour safety, particularly in areas with complex terrain and amid unfavourable weather conditions, for the sake of the country, people, and national development.

June 30, 2024 marked the completion of work on the 74.4km stretch from Thanh Hoa to Nam Dinh. This sub-project is expected to help ease the pressure on and prevent overload on the existing 500kV lines.

It will also contribute to the enhancement of transmission stability and the increase of supply from power sources in the north-central region to the North, a big electricity consumption centre.

An array of difficulties and challenges also occurred during the implementation of this sub-project such as the construction of 48 bases in mountainous areas. However, engineers and labourers worked with the highest sense of responsibility to finish it on schedule.

PM Pham Minh Chinh examines the construction of a section of the Circuit-3 500kV transmission line project, Quang Trach – Pho Noi, in Thanh Hoa province on June 22. (Photo: VNA)

Braving all difficulties and challenges during the implementation of this sub-project, engineers and labourers worked with the highest sense of responsibility to finish it on schedule.

The operation of the Thanh Hoa – Nam Dinh section on schedule has provided an impulse for the entire project from Quang Trach to Pho Noi to be completed as directed by the PM./. VNA