25 years of safe and effective operation of North - South 500kV transmission line

Officially operated since 1994, the North - South 500kV ultra high-voltage power transmission line - circuit 1, with a length of 1,487km, has always promoted its role, meeting the power demand for socio-economic development of the country.

Miracle in electricity construction industry

In the earlier 1990s, the South had a great demand on power consumption but its on-site supply was inadequate, so power was alternatively cut-off to limit demand of load.

In order to overcome this situation, the Government decided to construct North - South 500kV ultrahigh-voltage transmission line - circuit 1, with the task of transmitting power from the North to the Central and the South being in serious shortage of power, and connecting power system amongst the three regions at the same time. This is a historic decision as, for the first time, Vietnam had constructed a 500kV ultrahigh-voltage transmission line with a length of nearly 1,500km, which was one of the longest ultrahigh-voltage lines in the world at that time.

The project was commenced on 5th April 1992 and energized on 27th May 1994, after 2 years of construction in a rapid speed, with the method of combining design and construction at the same time. This is an unprecedented miracle. The North - South 500kV transmission line - circuit 1, is 1,487km long, with starting point at 500kV distribution yard of Hoa Binh Hydropower Plant and the ending one at 500kV Phu Lam Substation together with 5 500kV substations, which forms the system of North - South 500kV power transmission line.

This “spine” not only fulfills the urgent mission of resolving power shortages, creating a foundation and driving force for socio-economic development in the central and southern provinces, but also connects the power grids of 3 regions, unifying the national power system, improving safety, stabilizing power supply and quality, and facilitating reasonable utilization of power sources in the system at the same time.

Prime Minister Vo Van Kiet inspecting the erection of 500kV electric posts - Documentary photo

Miracle followed by miracle

After over 10 years of operating the North - South 500kV ultrahigh-voltage transmission line, circuit 1, on 23rd September 2005, Vietnam’s Power sector made another new miracle: Completing and putting into operation the North - South 500kV ultrahigh-voltage transmission line, circuit 2, (from 500kV Thuong Tin substation to 500kV Phu Lam substation) with a length of nearly 1,600km. Thus, the North - South 500kV power transmission system has had two parallel circuits to create a strong connection, safe and reliable operation for the national power transmission system.

The construction of circuit 1 was participated by foreign experts from design consultancy, technical supervision, direct checking and acceptance, etc., the work of circuit 2 was entirely undertaken by Vietnamese officials and engineers, marking the outstanding growth of the staffs and employees of Vietnam’s Power Sector.

So far, after 25 years of operation, the North - South 500kV power transmission system has made great contributions to the socio-economic development of the country, playing a crucial role in the national power transmission system.

On 4th December 2017, the Prime Minister issued Decision No. 1944/QD-TTg to put the 500kV transmission system into the List of important projects related to national security.

EVNNPT applying unmanned aerial vehicle to check operation of transmission power grid - Photo: Ngan Ha

Establishment of EVNNPT - turning point of Power transmission

On 1st July 2008, the National Power Transmission Corporation was established with the main task of construction investment and operation management of national power transmission system, including 220kV and 500kV transmission lines and substations nationwide. Thereby, construction investment and operation management of the national power transmission system are concentrated at a point, opening a new development period in the field of power transmission.

Over 11 years of operation, EVNNPT has gained many great achievements in the field of operation management of power transmission system and increasingly affirmed its position. After 25 years, since the completion of the North - South 500kV transmission line, circuit 1, the national power transmission system has dramatically developed in both scale and quality and technology. In ASEAN, EVNNPT has been ranked 3rd in operation management of transmission line and 4th in total capacity of transformers.

The national power transmission system has been increasingly synchronous and modern, covering all over provinces and cities throughout the country; connecting with power transmission systems of China, Laos and Cambodia. At the same time, it has met requirements of connection, capacity release of power sources and ensured the power supply as required by loads. EVNNPT has made a crucial contribution to ensuring sufficient power supply for the country’s socio-economic development.

Currently, EVNNPT is urgently implementing construction for the project cluster of Vung Ang - Quang Trach - Doc Soi - Pleiku 2 500kV transmission line with a total length of nearly 750km, completing the 500kV - circuit 3 from the North to the South and strengthening the transmission capacity of 500kV power transmission system, ensuring stable power supply for the South in the period of 2020 and the subsequent years under the context that the Southern power system cannot balance supply and demand.

PTC3’s workers conducting detection at Pleiku 500kV substation - Photo: Ngan Ha

In 2019, EVNNPT was rated by Fitch Ratings as a long-term foreign currency issuer default rating at BB level (equal to the national credit rating and that of Vietnam Electricity). Regarding the independent credit, EVNNPT was rated at BB+ by Fitch Ratings. This result has helped EVNNPT consolidate its credit level and enhance the transparency, in line with international standards, allowing EVNNPT to diversify financial resources and create many advantages in mobilizing capital for construction investment.

The application of scientific and technological achievements is always focused on by EVNNPT. As a result, the national power transmission system has been gradually synchronized and modernized. The management and technical personnel of the Corporation has been increasingly growing and mastering modern technologies. EVNNPT is focusing on researching and applying achievements of Industrial Revolution 4.0, contributing to improving production and business efficiency as well as labour productivity.

PTC 2’s workers participating in supervising construction of Vung Ang - Doc Soi - Pleiku 2 500kV transmission line - Photo: Ngan Ha

Toward the future...

With the goal of sustainable development, reaching the regional and international ranking, EVNNPT set a strategic goal to turn the National Power Transmission Corporation into one of the top four power transmission organizations in the ASEAN region by 2020; striving to become one of the top 10 power transmission organizations in Asia by 2025; reaching the world advanced level in the field of power transmission by 2030.

In order to realize this goal, EVNNPT must implement many synchronous solutions such as construction investment; operation management; finance and capital mobilization; application of science and technology; corporate governance, organizing apparatus and human resource development; environmental protection, response to climate change; communications and international relations, etc.

The tasks set for the coming years are very tough, EVNNPT will face many difficulties and challenges, which requires every staff and employee to strive and make more efforts to successfully perform the tasks assigned.


  • 27/05/2019 03:07
  • evn.com.vn